Methods and compositions relating to hydrodissection

Abstract

The technology described herein is directed to compositions comprising gellan gum for hydrodissection.

Description

METHODS AND COMPOSITIONS RELATING TO HYDRODISSECTIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 63 / 595,910 filed November 3, 2023 and U.S. Provisional Application No. 63 / 613,927 filed December 22, 2023 the contents of which are incorporated herein by reference in their entireties.TECHNICAL FIELD

[0002] The technology described herein relates to hydrodissection and tissue displacement.BACKGROUND

[0003] Tissue displacement is used to separate a target and non-target in a patient, providing a safer physical environment for a number of medical interventions, such as ablation, excision, or inserting of medical devices. Introducing separation between a target and non-target reduces physical damage to the non-target and minimizes the non-target’s exposure to the intervention. For example, microwave ablation is used to treat some cancers. But when this therapy is used on tumors adjacent to critical organs, cardiac, bowel, colon, pancreatic, diaphragmatic, and gastrointestinal injuries have resulted in severe morbidity and mortality.

[0004] Hydrodissection (e.g., with saline), injected gas, and / or balloon inflation have been used to try and reduce such collateral damage, but these approaches provide limited benefits. For example, hydrodissection suffers from: a) a lack of control, b) poor retention time, and c) limited insulation abilities. There is a clinically unmet need for an injectable, conformable, and shapeable physical barrier system that can permit temporally stable planar tissue separation.SUMMARY

[0005] The technology described herein is directed to compositions and methods that provide improved tissue displacement and / or hydrodissection.

[0006] In one aspect of any of the embodiments, described herein is a method comprising placing a composition comprising gellan gum between a target location and at least one adjacent non- target tissue or at least one adjacent non-target organ. In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method comprising placing the composition between a target location and at least one adjacent non-target tissue or at least one adjacent non-target organ.

[0007] In some embodiments of any of the aspects, the composition comprising gellan gum further comprises at least one of: alginate; chitosan; a polyacrylic acid; a polyethylene glycol; a polyethylene oxide; a co-block polymer (e.g., poly(lactic-co-glycolic acid); and a poloxamer.

[0008] In some embodiments of any of the aspects, the composition comprising gellan gum comprises neat (unmodified) gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises at least one of modified gellan gum and cross-linked gellan gum. In1SUBSTITUTE SHEET (RULE 26)some embodiments of any of the aspects, the at least one of modified gellan gum and cross-linked gellan gum comprises high acyl gellan gum. In some embodiments of any of the aspects, the at least one of modified gellan gum and cross-linked gellan gum comprises low acyl gellan gum.

[0009] In some embodiments of any of the aspects, the composition comprising gellan gum comprises from 0.01-20 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises from 0.05-10 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises from 0.1-3 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises more than 0.1 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises less than 3 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises 1.4-1.6 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises 1.5 wt% gellan gum.

[0010] In some embodiments of any of the aspects, the composition comprising gellan gum further comprises at least one cross-linking ion. In some embodiments of any of the aspects, the at least one cross-linking ion comprises one or more of Mg2+, Ca2+, Na+, and K+. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises at least one of: at least one Mg2+salt, at least one Ca2+salt, at least one Na+salt, and at least one K+salt. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises at least one of: MgCL, NaCl, KC1, phosphate buffered saline (PBS), CaCL: DMEM; and EMEM. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a concentration of 0.1 mmol / L to 3.0 mol / L. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a concentration of 0.25 to 2.0 mmol / L. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises Ca2+at a concentration of 1.25 to 1.75 mmol / L. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises Mg2+at a concentration of 0.25 to 0.75 mmol / L. In some embodiments of any of the aspects, the composition comprising gellan gum is at a temperature of no more than 40 °C.

[0011] In some embodiments of any of the aspects, the target is a tumor, abscess, scar tissue, nerve tissue, or tissue in need of surgical resection. In some embodiments of any of the aspects, the target is a tumor. In some embodiments of any of the aspects, the target is adjacent to, part of, or in contact with the kidney, liver, prostate, bone, breast, heart, bowel, colon, pancreas, diaphragm, or gastrointestinal system.

[0012] In some embodiments of any of the aspects, the method further comprises administering a hyperthermal ablation treatment to the target. In some embodiments of any of the aspects, the target is insulated from heat, cold, and / or light as compared to the absence of the composition comprising gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum2SUBSTITUTE SHEET (RULE 26)reflects light. In some embodiments of any of the aspects, the hyperthermal ablation treatment is a microwave ablation procedure, a computed tomography (CT) ablation procedure, or an ultrasound (US) ablation procedure. In some embodiments of any of the aspects, the hyperthermal ablation treatment is a microwave ablation procedure.

[0013] In some embodiments of any of the aspects, the method further comprises administering a radiation treatment to the target. In some embodiments of any of the aspects, the method further comprises administering an acid, an alkali, cryotherapy, a photodynamic therapy, a high intensity focused ultrasound, or electrocautery to the target. In some embodiments of any of the aspects, the method further comprises dissecting, excising or removing the target. In some embodiments of any of the aspects, the method further comprises placing an endoscopic device within the composition comprising a gellan gum. In some embodiments of any of the aspects, the method further comprises placing an implantable device, catheter, leads, stimulator, probe, or material within the composition comprising a gellan gum or on the target. In some embodiments of any of the aspects, the method further comprises administering a drug to the composition comprising a gellan gum or wherein the composition comprising a gellan gum further comprises a drug.

[0014] In some embodiments of any of the aspects, the method further comprises administering a composition comprising one or more of:EDTA; glucose; glutathione; saline; and sodium bicarbonate to the subject. In some embodiments of any of the aspects, the glucose is a 5% glucose solution. In some embodiments of any of the aspects, the glucose is a 2-4% glucose solution. In some embodiments of any of the aspects, the glucose is a 4-6% glucose solution. In some embodiments of any of the aspects, the glucose is a 5% glucose solution. In some embodiments of any of the aspects, the saline is a normal saline solution.

[0015] In some embodiments of any of the aspects, the subject is not administered hydrodissection comprising or consisting of saline injection or dextrose solution injection. In some embodiments of any of the aspects, the subject is not administered hydrodissection comprising or consisting of polyethylene glycol (PEG), collagen, pluronic 407, or hyaluronic acid. In some embodiments of any of the aspects, the composition comprising gellan gum does not comprise polyethylene glycol (PEG), collagen, poloxamer 407, or hyaluronic acid.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figs. 1A-1E depict hydrodissection functionality needs and gel comparison. Fig. 1 A) Separation of organs desired using hydrodissection media; Fig. IB) Case study demonstrating the3SUBSTITUTE SHEET (RULE 26)limitations of hydrodissection using SoC procedures: (1) Tumor in segment II of the liver adjacent to the stomach in a non-surgical candidate, (2) Contrast injection attempting fluidic hydrodissection showing poor distension, (3) Air injected for anterior abdomen showing minimal protection, (4) Use of an inflated balloon to displace the stomach from the tumor; Fig. 1C) Functionalities of gel hydrodissection enabled by tunable material properties; Fig. ID) Comparison of functionality achievable by gel hydrodissection presented herein compared to SoC methods; Fig. IE) Hy drodissection achieved by the tunable gel platform both between tissues (inter-tissue; top) and within tissues (intra-tissue; bottom).

[0017] Figs. 2A-2J demonstrate neat GG hydrodissection gel characterization. Fig. 2A) GG helical coil entanglement facilitating reversible sol-gel transition at 60°C and dissociation under syringe shear force; Fig. 2B) Oscillatory shear amplitude sweep of GG gels with strain %-dependent viscoelastic behavior (storage > loss modulus at low strain and loss > storage modulus at high strain); Fig. 2C) Tan5 of GG gels from oscillatory shear amplitude sweep; Fig. 2D) Gels ejected from syringe and shape-holding comparison with saline; Fig. 2E) Frequency sweeps of GG gels with dominating elastic behavior across frequencies and modulus tunable by GG concentration; Fig. 2F) Pressure- controlled syringe stopper displacement experiment for determining “residence time”; Fig. 2G) Residence time of saline and GG gels under corresponding constant pressures; Fig. 2H) Viscosity of GG gels across shear rates; Fig. 21) Degradation of GG1.5% in EDTA-based solutions; Fig. 2J) Absorbance spectrum of GG gels across concentrations, all optically transparent throughout the visible range.

[0018] Figs. 3A-3G depict induced granular GG-PDx gels for intra-tissue hydrodissection using peritoneal dialysis (PD) cation concentration-matching. Fig. 3A) In situ granulation at the syringeneedle interface (scale bar = 2mm), GG-PDx gel dyed blue and dispersed in water for visualization; Fig. 3B) Intra-tissue hydrodissection distances created by injection of saline (blue), GG1.5% (orange), and GG-PDx (purple) in porcine liver tissue (scale bars = 2mm); Fig. 3C) Frequency sweeps; Fig. 3D) Viscosity profile, Fig. 3E) Stress profile of GG1.5% and GG-PDx gels post-ejection from 20G needles; Fig. 3F) Degradation of GG1.5% and GG-PDx gel in EDTA / glucose; Fig. 3G) Triggerable in situ degradation of GG-PDx within liver tissue (scale bars = 2mm).

[0019] Figs. 4A-4F demonstrate benchtop ablation thermal protection in porcine liver. Fig. 4A) MWA in saline with conductive and convective heating. Scale bars = 1 cm; Fig. 4B) Top: MWA with saline (outlined in blue) filling space in between tissues (dotted white); Bottom: MWA with GG (outlined in orange) filling space in between tissues (dotted white). Scale bars = 1 cm; Fig. 4C) Temperature profiles of saline (blue) and GG (orange) inter-tissue hydrodissection spacings; Fig. 4D) MWA with GG-PDx intra-tissue hydrodissection. Scale bars = 1 cm; Fig. 4E) Average temperatures along original tissue planes (red) and hydrodissected tissue planes (orange) for the left (dotted) and4SUBSTITUTE SHEET (RULE 26)right-side (solid) slits shown in (Fig. 4E); Fig. 4F) Cross-section of ablation zone with intra-tissue gel hydrodissection. Scale bars = 1 cm.

[0020] Figs. 5A-5I depict in vivo ablation protection. Fig. 5 A) Ultrasound images of hydrodissection pockets created by saline (top row, blue) and by GG (bottom row, orange). Scale bar = 1 cm; Fig. 5B) Minimum hydrodissection pocket distance created post-injection. Inset: focused view on initial distances created by injected solution (50mL for all saline and 20mL for gels); Fig. 5C) Ultrasound image of ablation and temperature probes placement with intraperitoneally injected GG1.5% in between the liver and stomach (scale bar = 1 cm); Fig. 5D) Temperatures recorded at the hepatic ablation site (red) and at the stomach (orange), separated by the GG hydrodissection volume; Fig. 5E) CT image post-ablation with GG hydrodissection pocket remaining intact (orange) (scale bar = 1 cm); histology post-ablation of: Fig. 5F) Liver, Fig. 5G) Peritoneum near ablation probe, Fig. 5H) Lesser curvature of the stomach adjacent to the gel (closest to hepatic ablation zone), Fig. 51) Greater curvature of the stomach located away from ablation zone.

[0021] Fig. 6 depicts a pressure-controlled syringe stopper displacement experiment setup for measuring dissipation time.

[0022] Figs. 7A-7E depict histological analysis of Fig. 7A) liver in the ablation zone (showing coagulative necrosis), Fig. 7B) peritoneal tissue near the ablation zone (showing damage from lack of protection from the MWA probe), Fig. 7C) peritoneal tissue distance from the ablation zone, Fig. 7D) stomach near the ablation zone protected by the hydrodissective GG gel, Fig. 7E) stomach tissue distance from the ablation zone (showing no differences from the stomach tissue closest to the ablation zone protected by the GG gel).

[0023] Figs. 8A-8B depict the long-term behavior and retention of GG. Fig. 8A depicts a graph of GG retention. Fig. 8B depicts histological analysis at the injection site.DETAILED DESCRIPTION

[0024] As described herein, the inventors have developed compositions comprising gellan gum that provide long-lasting and highly insulating / protective tissue displacement. For example, the compositions described herein provide tissue displace that lasts 24 times longer than the standard of care, using 40% less injected volume than the standard of care, while providing a stable thermal barrier.

[0025] In one aspect of any of the embodiments, described herein is a composition comprising gellan gum.

[0026] In one aspect of any of the embodiments, described herein is a method comprising placing a composition comprising gellan gum between a target location and at least one adjacent nontarget tissue or at least one adjacent non-target organ. In one aspect of any of the embodiments, described herein is a method comprising placing a composition comprising gellan gum between a5SUBSTITUTE SHEET (RULE 26)target location and at least one adjacent non-tar et tissue or at least one adjacent non-target organ in a subject.

[0027] In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of placing the composition between a target location and at least one adjacent non-target tissue or at least one adjacent non-target organ. In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of placing the composition between a target location and at least one adjacent non-target tissue or at least one adjacent non-target organ in a subject. In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of placing the composition between a first location and at least one adjacent location, tissue, or organ in a subject. Optionally, in some embodiments, the method of the above aspect is not a method for treatment of the human or animal body by surgery or therapy practiced on the human or animal body.

[0028] In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of placing the composition between a target location and at least one adjacent non-target tissue or at least one adjacent non-target organ. In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of placing the composition between a target location and at least one adjacent non-target tissue or at least one adjacent non-target organ in a subject. In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use as a tissue shielding agent. In some embodiments of any of the aspects, the tissue shielding agent is introduced between a therapeutic ablation target location situated within the body of a patient and at least one adjacent non-target tissue or at least one adjacent non-target organ. In some embodiments of any of the aspects, a tissue shielding agent shields a tissue from one or more of: surgical resection, hyperthermal ablation, radiation, acid, alkali, cryotherapy, photodynamic therapy, high intensity focused ultrasound, or electrocautery. In some embodiments of any of the aspects, a tissue shielding agent shields a tissue from one or more of: surgical resection and hyperthermal ablation. In some embodiments of any of the aspects, a tissue shielding agent shields a tissue from surgical resection. In some embodiments of any of the aspects, a tissue shielding agent shields a tissue from hyperthermal ablation. In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in tissue displacement and / or hydrodissection. A tissue shielding agent can reduce or prevent a stimulus or treatment from reaching or affecting a non-target tissue. In some embodiments of any of the aspects, the composition is introduced between a therapeutic ablation target location situated within the body of a patient and at least one adjacent non-target tissue or at least one adjacent non-target organ.

[0029] In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of hydrodissection.6SUBSTITUTE SHEET (RULE 26)

[0030] In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of ablation or excision treatment in a subject in need thereof.

[0031] In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of treating cancer in a subject in need thereof, optionally wherein the method comprises placing the composition between a target location and at least one adjacent nontarget tissue or at least one adjacent non-target organ in a subject and administering an ablation or excision treatment to the target location. In one aspect of any of the embodiments, described herein is a composition comprising gellan gum and an anti-cancer agent for use in a method of treating cancer in a subject in need thereof, optionally wherein the method comprises placing the composition between a target location and at least one adjacent non-target tissue or at least one adjacent non-target organ in the subject.

[0032] In some embodiments of any of the aspects, the cancer can be melanoma, squamous cell carcinoma, breast cancer, lung cancer, sarcoma, renal cancer, liver cancer, colon cancer, lymphoma, or prostate cancer.

[0033] In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of treating arrythmia in a subject in need thereof, optionally wherein the method comprises placing the composition between a target cardiac location and at least one adjacent non-target tissue or at least one adjacent non-target organ in a subject and administering an ablation treatment to the target cardiac location.

[0034] In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of treating liver cancer in a subject in need thereof, optionally wherein the method comprises placing the composition between a target hepatic location and at least one adjacent non-target tissue or at least one adjacent non-target organ in a subject and administering an ablation or excision treatment to the target hepatic location. In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of treating liver cancer in a subject in need thereof, optionally wherein the method comprises placing the composition between a target hepatic location and at least one adjacent non-target tissue or at least one adjacent non-target organ in a subject and administering an ablation treatment to the target hepatic location.

[0035] In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of treating cancer metastasis in a subject in need thereof, optionally wherein the method comprises placing the composition between a target metastasis location and at least one adjacent non-target tissue or at least one adjacent non-target organ in a subject and administering an ablation or excision treatment to the target metastasis location. In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of treating liver cancer in a subject in need thereof, optionally wherein the method comprises placing the composition between a target metastasis location and at least one adjacent non-target tissue or at least7SUBSTITUTE SHEET (RULE 26)one adjacent non-target organ in a subject and administering an ablation treatment to the target metastasis location. For example, the metastasis can be a metastasis of liver cancer. Alternatively, the metastasis can be a metastasis in the liver. Alternatively, the metastasis can be a lymph node metastasis. Metastasis can be of melanoma, squamous cell carcinoma, breast cancer, lung cancer, sarcoma, renal cancer, liver cancer, colon cancer, lymphoma, or prostate cancer.

[0036] In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of treating colon cancer in a subject in need thereof, optionally wherein the method comprises placing the composition between a target colon location and at least one adjacent non-target tissue or at least one adjacent non-target organ in a subject and administering an ablation or excision treatment to the target colon location. In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of treating colon cancer in a subject in need thereof, optionally wherein the method comprises placing the composition between a target colon location and at least one adjacent non-target tissue or at least one adjacent non-target organ in a subject and administering an ablation treatment to the target colon location.

[0037] In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of treating renal cancer in a subject in need thereof, optionally wherein the method comprises placing the composition between a target renal location and at least one adjacent non-target tissue or at least one adjacent non-target organ in a subject and administering an ablation or excision treatment to the target renal location. In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of treating renal cancer in a subject in need thereof, optionally wherein the method comprises placing the composition between a target renal location and at least one adjacent non-target tissue or at least one adjacent non- target organ in a subject and administering an ablation treatment to the target renal location.

[0038] In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of treating kidney stones in a subject in need thereof, optionally wherein the method comprises placing the composition between a target renal location and at least one adjacent non-target tissue or at least one adjacent non-target organ in a subject and administering an ablation or excision treatment to the target renal location. In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of treating kidney stones in a subject in need thereof, optionally wherein the method comprises placing the composition between a target renal location and at least one adjacent non-target tissue or at least one adjacent non- target organ in a subject and administering an ablation treatment to the target renal location.

[0039] In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of treating prostate cancer in a subject in need thereof, optionally wherein the method comprises placing the composition between a target prostate location and at least8SUBSTITUTE SHEET (RULE 26)one adjacent non-target tissue or at least one adjacent non-target organ in a subject and administering an ablation or excision treatment to the target prostate location. In one aspect of any of the embodiments, described herein is a composition comprising gellan gum for use in a method of treating prostate cancer in a subject in need thereof optionally wherein the method comprises placing the composition between a target renal location and at least one adjacent non-target tissue or at least one adjacent non-target organ in a subject and administering an ablation treatment to the target prostate location.

[0040] In some embodiments of any of the aspects, the composition comprising gellan gum comprises gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum consists of gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum consists essentially of gellan gum.

[0041] In some embodiments of any of the aspects, the composition comprising gellan gum does not comprise a polymer other than gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum does not comprise a polysaccharide other than gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum does not comprise a gelling agent other than gellan gum.

[0042] Gellan gum is an anionic polysaccharide, specifically a polymeric tetrasaccharide, having the structure of [D-Glc(pl^4)D-GlcA(pl^4)D-Glc(pl^4)L-Rha(al^3)]n, also shown Formula I below. The repeating tetrasaccharide comprises two residues of D-glucose and one of each residues of L-rhamnose and D-glucuronic acid. Gellan gum is also known as E418 or by the CAS number 71010-52-1 and is commercially available.Formula I

[0043] The gellan gum can be modified, cross-linked, and / or unmodified gellan gum.9SUBSTITUTE SHEET (RULE 26)

[0044] Neat (unmodified) gellan gum is shown in Formula I. In some embodiments of any of the aspects, the gellan gum comprises neat (unmodified) gellan gum. In some embodiments of any of die aspects, the gellan gum consists of neat (unmodified) gellan gum. In some embodiments of any of the aspects, the gellan gum consists essentially of neat (unmodified) gellan gum.

[0045] Gellan gum can be modified, e.g., by attaching side groups to the polymer. The most common modification is the attachment of acyl groups to glucose residues of the polymer. When such acyl groups are present on the glucose resides, the gellan gum is referred to has “high acyl” gellan gum. When such acyl groups are not present on the glucose residues, the gellan gum is referred to as “low acyl” gellan gum. High acyl gellan gum is known to form more elastic hydrogels, while low acyl gellan gum is known to form harder, more brittle hydrogels. The gellan gum may be entirely low acyl, entirely high acyl, or a mixture of the two types.

[0046] In some embodiments of any of the aspects, the gellan gum comprises low acyl gellan gum. In some embodiments of any of the aspects, the gellan gum consists of low acyl gellan gum. In some embodiments of any of the aspects, the gellan gum consists essentially of low acyl gellan gum.

[0047] In some embodiments of any of the aspects, the gellan gum comprises high acyl gellan gum. In some embodiments of any of the aspects, the gellan gum consists of high acyl gellan gum. In some embodiments of any of the aspects, the gellan gum consists essentially of high acyl gellan gum.

[0048] In some embodiments of any of the aspects, the gellan gum comprises both low acyl gellan gum and high acyl gellan gum.

[0049] In some embodiments of any of the aspects, the gellan gum is cross-linked. As used herein, “cross-linked” refers to the existence of one or more chemical bond between at least two separate chains in a polymer.

[0050] In some embodiments of any of the aspects, the gellan gum comprises at least one of modified gellan gum and cross-linked gellan gum. In some embodiments of any of the aspects, the at least one of modified gellan gum and cross-linked gellan gum comprises high acyl gellan gum. In some embodiments of any of the aspects, the at least one of modified gellan gum and cross-linked gellan gum comprises low acyl gellan gum. In some embodiments of any of the aspects, the at least one of modified gellan gum and cross-linked gellan gum comprises low acyl gellan gum and high acyl gellan gum.

[0051] The composition comprising gellan gum can comprise a solution or hydrogel of gellan gum, e.g., the composition comprising gellan gum can comprise gellan gum and water. In some embodiments of any of the aspects, the water is provided as saline or a physiologically compatible buffer.

[0052] In some embodiments of any of the aspects, the composition comprising gellan gum comprises from 0.001-50 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises from 0.01-20 wt% gellan gum. In some embodiments10SUBSTITUTE SHEET (RULE 26)of any of the aspects, the composition comprising gellan gum comprises from 0.05-10 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises from 0.1-3 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises from 1.4-1.6 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises 1.5 wt% gellan gum.

[0053] In some embodiments of any of the aspects, the composition comprising gellan gum comprises more than 0.1 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises 0.1-20 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises 0.1-10 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises 0.1-5 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises 0.1-1 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises less than 3 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises 0.001-3 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises 0.01-3 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises 0.1-3 wt% gellan gum. In some embodiments of any of the aspects, the composition comprising gellan gum comprises 1-3 wt% gellan gum.

[0054] In some embodiments of any of the aspects, the composition comprising gellan gum can comprise one or more additional polymers. Exemplary, non-limiting additional polymers include polylactide (PLA): polyglycolide (PGA); poly-(e-caprolactone) (PCL); polyphosphazenes; polyorthoesters; polyanhydrides; poly(a-hydroxy esters); poly(ether esters); copolymers comprising lactide of glycolide and s -caprolactone or trimethylene carbonate; poly(polyol sebacate) elastomers; elastomers; poly(polyol citrate); polyesters; poly(glycolic acid); poly(lactic acid); poly (caprolactone); poly(lactic-co-glycolic acid); poly(butylene succinate); poly(trimethylene carbonate); poly(p- dioxanone); poly(butylene terephthalate); poly(ester amide)s; Hybrane™ S1200; DegraPol™; polyurethanes; polyanhydrides; poly[(caboxyphenoxy) propane-sebacic acid]; polyphsophoesters; poly[bis(hydroxyethyl) terephthalate-ethyl orthophosphorylate / terephthaloyl chloride]; poly(ortho esters); poly(alkyl cyanoacrylates); polyfbulyl cyanoacrylate); polyethers; polyethylene glycol); poly(amino acids); tyrosine derived polycarbonate; microbial polyesters; poly (P-hydroxy alkanoate); poly (hydroxy butyrate); poly(hydroxybutyrate-co-hydroxyvalerate); collagen; albumin; gluten; chitosan; hyaluronate; cellulose; alginate; and starch.

[0055] In some embodiments of any of the aspects, the composition comprising gellan gum further comprises at least one of alginate; chitosan; polyacrylic acid; a polyethylene glycol; a polyethylene oxide; a co-block polymer (e.g., poly(lactic-co-glycolic acid); and a poloxamer. Coblock11SUBSTITUTE SHEET (RULE 26)polymers can include, by way of non-limiting example, PEG-PLGA-PEG, or any combination and / or permutation of at least two of PCL, PEG, PLA, PVA, PLGA.

[0056] Poloxamers are water-soluble nonionic triblock copolymers formed by polar (poly ethylene oxide) and non-polar (poly propylene oxide) blocks, which confer amphiphilic and surface active properties to the polymers. Poloxamers are known in the art and commercially available. For further discussion, see, e.g., Russo et al. Pharmaeutics 11 (12) :671 (2019), which is incorporated by reference herein in its entirety.

[0057] Gellan gum can be crosslinked by cross-linking ions, e.g., positive ions or solutions comprising positive ions. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises at least one cross-linking ion. In some embodiments of any of the aspects, the at least one cross-linking ion comprises one or more of Mg2, Ca2+, Na+, and K+. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises at least one of: at least one Mg2+salt, at least one Ca2+salt, at least one Na+salt, and at least one K+salt.

[0058] In some embodiments of any of the aspects, the at least one cross-linking ion comprises one or both of Mg2+and Ca2+. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises at least one of: at least one Mg2+salt and at least one Ca2+salt. In some embodiments of any of the aspects, the at least one cross-linking ion comprises Mg2+. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises at least one Mg2+salt. In some embodiments of any of the aspects, the at least one cross-linking ion comprises Ca2+. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises at least one Ca2+salt.

[0059] Cross-linking ions can be provided by a biological medium, e.g., PBS or a cell culture medium such as DMEM or EMEM. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises MgCk NaCl, KC1, phosphate buffered saline (PBS), CaCk, Dulbecco’s Modified Eagle Medium (DMEM), and / or Eagle’s Minimum Essential Medium (EMEM). In some embodiments of any of the aspects, the composition comprising gellan gum further comprises MgCk, NaCl, KC1, phosphate buffered saline (PBS), Dulbecco’s phosphate buffered saline (DPBS), Hank’s balanced salt solution (HBSS), Earle’s balanced salt solution (EBSS), CaCh, Dulbecco’s Modified Eagle Medium (DMEM), Eagle’s Minimum Essential Medium (EMEM), Minimum Essential Medium (MEM), Glasgow Minimum Essential Medium (GMEM), Basal Medium Eagle (BME), and / or Roswell Park Memorial Institute (RPMI) medium.

[0060] In some embodiments of any of the aspects, the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a concentration of 0.01 mmoVL to 30.0 mol / L. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a concentration of 0.1 mmol / L to 3.0 mol / L. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a12SUBSTITUTE SHEET (RULE 26)concentration of 0.25 to 2.0 mmol / L. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises Ca2+at a concentration of 1.25 to 1.75 mmol / L. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises Mg2+at a concentration of 0.25 to 0.75 mmol / L.

[0061] In some embodiments of any of the aspects, the composition comprising gellan gum further comprises one or more positive ions at a collective concentration of 0.01 mmol / L to 30.0 mol / L. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises one or more positive ions at a collective concentration of 0.1 mmol / L to 3.0 mol / L. In some embodiments of any of the aspects, the composition comprising gellan gum further comprises one or more positive ions at a collective concentration of 0.25 to 2.0 mmol / L.

[0062] The viscosity of a composition comprising gellan gum can be temperature dependent, with higher temperatures providing lower viscosity. It can therefore be advantageous to heat the composition comprising gellan gum before placing the composition according to the methods described herein, e.g., to make injection easier and / or faster. Accordingly, in some embodiments of any of the embodiments, the gellan gum is at a temperature of greater than 20 °C before or during the placing step. In some embodiments of any of the embodiments, the gellan gum is at a temperature of greater than 22 °C before or during the placing step. In some embodiments of any of the embodiments, the gellan gum is at a temperature of greater than 37 °C before or during the placing step. In some embodiments of any of the embodiments, the gellan gum is at a temperature of no greater than 40 °C before or during the placing step.

[0063] In some embodiments of any of the embodiments, the gellan gum is at a temperature of from 20-40 °C before or during the placing step. In some embodiments of any of the embodiments, the gellan gum is at a temperature of from 22-40 °C before or during the placing step. In some embodiments of any of the embodiments, the gellan gum is at a temperature of from 37-40 °C before or during the placing step.

[0064] In some embodiments of any of the embodiments, the gellan gum is at a temperature of from 20-44 °C before or during the placing step. In some embodiments of any of the embodiments, the gellan gum is at a temperature of from 22-44 °C before or during the placing step. In some embodiments of any of the embodiments, the gellan gum is at a temperature of from 37-44 °C before or during the placing step.

[0065] In some embodiments of any of the embodiments, the gellan gum is at a temperature of from 20-80 °C before or during the placing step. In some embodiments of any of the embodiments, the gellan gum is at a temperature of from 22-80 °C before or during the placing step. In some embodiments of any of the embodiments, the gellan gum is at a temperature of from 37-80 °C before or during the placing step.13SUBSTITUTE SHEET (RULE 26)

[0066] In some embodiments of any of the aspects, the method described herein can further comprise a first step of heating the composition comprising the gellan gum to one of the temperatures or temperature ranges detailed herein.

[0067] To prepare the composition comprising gellan gum, a mixture comprising water and gellan gum can be heated to at least 55 °C, or at least 60 °C to. A gel will form when the solution is cooled. Once the gel is formed, it can withstand temperatures of at least 100 °C. Compositions comprising gellan gum can be stored at 22 °C or lower, e.g., to maximize shelf-life.

[0068] As used herein “placing” refers to any suitable means for moving at least part of a composition comprising gellan gum from a first ex vivo location into a position which is between a target location and at least one adjacent non-target tissue or at least one adjacent non-target organ. In some embodiments, placing comprises physical human activity, e.g., an injection, an act of application, and / or manipulation of a delivery device or machine. Such activity can be performed, e.g., by a medical professional.

[0069] As used herein, “between” refers to a position at or across a space which separates a target and non-target. The space may be a pre-existing void, a pre-existing boundary, or created by the placement of the composition comprising gellan gum. Between may refer to position in part of the space separating the target and non-target, or the entirety of a plane, boundary, or surface separating the target and non-target.

[0070] As used herein, a “target” is a tissue, feature, or location which has been selected for a treatment or intervention (e.g., excision, ablation, pharmaceutical, or chemical treatment). As used herein, a “non-target” is a tissue, feature, or location which has been selected to not receive the treatment or intervention.

[0071] In some embodiments of any of the aspects, the target is a tumor, abscess, scar tissue, nerve tissue, or tissue in need of surgical resection. In some embodiments of any of the aspects, the target is a tumor, abscess, or scar tissue. In some embodiments of any of the aspects, the target is a tumor.

[0072] In some embodiments of any of the aspects, the target is adjacent to, part of, or in contact with an organ. In some embodiments of any of the aspects, the target is adjacent to an organ. In some embodiments of any of the aspects, the target is part of an organ. In some embodiments of any of the aspects, the target is in contact with an organ. In some embodiments of any of the aspects, the target is adjacent to, part of, or in contact with the kidney, liver, prostate, bone, breast, heart, bowel, colon, pancreas, diaphragm, gastrointestinal system, pleura, muscle soft tissue, brain, or any anatomic compartment. In some embodiments of any of the aspects, the target is adjacent to, part of, or in contact with the kidney, liver, prostate, bone, breast, heart, bowel, colon, pancreas, diaphragm, gastrointestinal system, pleura, muscle soft tissue, or brain. In some embodiments of any of the aspects, the target is adjacent to, part of, or in contact with the kidney, liver, prostate, bone, breast,14SUBSTITUTE SHEET (RULE 26)heart, bowel, colon, pancreas, diaphragm, or gastrointestinal system. When a treatment or intervention is administered to such targets, it is desirable to protect nearby non-targets from the treatment or intervention. For example, during cardiac ablation procedures, the methods described herein can protect structures such as the esophagus, phrenic nerve, and coronary arteries from excessive heat. As a further example, during liver ablation procedures, the methods described herein can protect nearby organs such as the gallbladder, bile ducts, and intestines. As a further example, during kidney ablation procedures, the methods described herein can protect nearby structures such as the meters, bladder, and rectum. As a further example, during prostate ablation procedures, the methods described herein can protect nearby structures such as the meters, bladder, and rectum.

[0073] In some embodiments of any of the aspects, after the composition comprising gellan gum is placed, the method further comprises administering an ablation treatment to the target. As used herein, “ablation treatment” refers to a procedme that destroys tissue, e.g., abnormal and / or diseased tissue. The composition comprising gellan gum can insulate and / or protect a non-target from heat, cold, radiation, chemicals, and / or light, e.g., as compared to the exposme the non-target would receive in the absence of the composition comprising gellan gum. In some embodiments of any of the aspects, the gellan gum reflects electromagnetic radiation, e.g., visible light.

[0074] In some embodiments of any of the aspects, the ablation treatment is a hyperthermal ablation treatment. In some embodiments of any of the aspects, the ablation treatment is a microwave ablation treatment. In some embodiments of any of the aspects, the ablation treatment is a computed tomography (CT) ablation treatment. In some embodiments of any of the aspects, the ablation treatment is an ultrasound (US) ablation treatment. In some embodiments of any of the aspects, the ablation treatment is radiation ablation treatment. In some embodiments of any of the aspects, the ablation treatment is laser ablation treatment. In some embodiments of any of the aspects, the ablation treatment is radiofrequency ablation treatment. In some embodiments of any of the aspects, the ablation treatment is cryoablation treatment. In some embodiments of any of the aspects, the ablation treatment is chemical ablation treatment.

[0075] In some embodiments of any of the aspects, after the composition comprising gellan gum is placed, the method further comprises administering a radiation treatment to the target. The composition comprising gellan gum can insulate and / or protect a non-target from radiation, e.g., as compared to the exposme the non-target would receive in the absence of the composition comprising gellan gum.

[0076] In some embodiments of any of the aspects, after the composition comprising gellan gum is placed, the method further comprises administering an acid, an alkali, cryotherapy, a photodynamic therapy, a high intensity focused ultrasound, or electrocautery to the target. The composition comprising gellan gum can insulate and / or protect a non-target from heat, cold, radiation, chemicals,15SUBSTITUTE SHEET (RULE 26)and / or light, e.g., as compared to the exposure the non-target would receive in the absence of the composition comprising gellan gum.

[0077] The placement of the composition comprising gellan gum can also provide physical separation of the target and non-target, making physical manipulation of the target less likely to damage or impact the non-target. In some embodiments of any of the aspects, after the composition comprising gellan gum is placed, the method further comprises dissecting, excising, or removing some or all of the target.

[0078] The placement of the composition comprising gellan gum can provide both physical separate of the target and non-target and a space where medical devices may be securely placed without physically contacting the non-target (or in some embodiments the target and the non-target). Accordingly, in some embodiments of any of the aspects, the method described herein can further comprising placing a device or material within the composition comprising the gellan gum. In some embodiments of any of the aspects, the composition comprising the gellan gum is placed first, and then at least part of the device or material is placed in the composition comprising the gellan gum. In some embodiments of any of the aspects, the device or material is placed first, and then the composition comprising the gellan gum is placed around or adjacent to at least part of the device or material. In some embodiments of any of the aspects, the device or material is placed in or coated in the composition comprising the gellan gum ex vivo, and then the combination of the device or material and composition comprising gellan gum is placed.

[0079] Exemplary devices or materials include but are not limited to an endoscopic device, a laparoscopic device, an implantable device, a catheter, one or more leads, a stimulator, a probe, or other materials used for therapeutic intervention or observation in patients.

[0080] Drugs or other therapeutic compounds can be placed in the composition comprising a gellan gum for delivery to the target. This can be a monotherapy or combined with other therapies described herein. For example, the composition comprising a gellan gum can further comprise one or more chemotherapeutics and be placed next to a target tumor as a monotherapy. Alternatively, the composition comprising a gellan gum can further comprise one or more chemotherapeutics and be placed next to a target tumor which is then subjected to an ablation or excision treatment, thereby providing a combination therapy.

[0081] As used herein, “drug” refers to an agent or compound which is therapeutically effective for the treatment of at least one condition in a subject. Therapeutic compounds are known in the art for a variety of conditions, see, e.g., the database available on the world wide web at drugs.com or the catalog of FDA-approved compounds available on the world wide web at catalog.data.gov / dataset / drugsfda-database; each of which is incorporated by reference herein in its entirety.16SUBSTITUTE SHEET (RULE 26)

[0082] In some embodiments of any of the aspects, the drug is an anti-cancer agent. As used herein “anti-cancer agent” refers to any chemical or biological agent with therapeutic usefulness in the treatment of diseases characterized by abnormal cell growth. Such diseases include tumors, neoplasms and cancer as well as diseases characterized by hyperplastic growth. Examples of anti-cancer agents can include, e.g., chemotherapeutics, radiation therapy reagents, immunotherapies, targeted therapies, or hormone therapies.

[0083] As used herein, the term “immunotherapy” refers to refers to any chemical or biological agent with therapeutic usefulness in the treatment of diseases characterized by abnormal cell growth by promoting, preserving, or increasing the activity of immune cells. Immunotherapies include immune checkpoint inhibitors, T-cell transfer therapy (e.g., CAR-T therapies), antibody therapies, treatment vaccines, and immune system modulators.

[0084] Immune checkpoint inhibitors inhibit one or more immune checkpoint proteins and are known in the art. Non-limiting examples of immune checkpoint inhibitors (with checkpoint targets and manufacturers noted in parentheses) can include:MGA271 (B7-H3: MacroGenics); ipilimumab (CTLA-4; Bristol Meyers Squibb); pembrolizumab (PD-1; Merck); nivolumab (PD-1; Bristol Meyers Squibb) ; atezolizumab (PD-L1; Genentech); galiximab (B7.1; Biogen); IMP321 (LAG3: Immuntep); BMS-986016 (LAG3; Bristol Meyers Squibb); SMB-663513 (CD137; Bristol-Meyers Squibb); PF- 05082566 (CD137; Pfizer); IPH2101 (KIR; Innate Pharma); KW-0761 (CCR4; Kyowa Kirin); CDX- 1127 (CD27; Called); MEDI-6769 (0x40; Medlmmune); CP-870,893 (CD40; Genentech); tremelimumab (CTLA-4; Medimmune); pidilizumab (PD-1; Medivation); MPDL3280A (PD-L1; Roche); MEDI4736 (PD-L1; AstraZeneca); MSB0010718C (PD-L1; EMD Serono); AUNP12 (PD-1; Aurigene); avelumab (PD-L1; Merck); durvalumab (PD-L1; Medimmune); IMP321, a soluble Ig fusion protein (Brignone et al., 2007, J. Immunol. 179:4202-4211); the anti-B7-H3 antibody MGA271 (Loo et al., 2012, Clin. Cancer Res. luly 15 (18) 3834); TIM3 (T-cell immunoglobulin domain and mucin domain 3) inhibitors (Fourcade et al., 2010, 1. Exp. Med. 207:2175-86 and Sakuishi et al., 2010, J. Exp. Med. 207:2187-94); anti-CTLA-4 antibodies described in US Patent Nos: 5,811,097; 5,811,097; 5,855,887; 6,051,227; 6,207,157; 6,682,736; 6,984,720; and 7,605,238; tremelimumab, (ticilimumab, CP-675,206); ipilimumab (also known as 10D1, MDX-D010); PD-1 and PD-L1 blockers described in US Patent Nos. 7,488,802; 7,943,743; 8,008,449; 8,168,757; 8,217,149, and PCT Published Patent Application Nos: W003042402, WO2008156712, W02010089411, WO2010036959, WO2011066342, WO2011159877, WO2011082400, and WO2011161699; nivolumab (MDX 1106, BMS 936558, ONO 4538); lambrolizumab (MK-3475 or SCH 900475); CT- 011; AMP -224; and BMS-936559 (MDX- 1105-01). The foregoing references are incorporated by reference herein in their entireties.

[0085] As used herein the term “chemotherapeutic agent" refers to any chemical or biological agent with therapeutic usefulness in the treatment of diseases characterized by abnormal cell growth.17SUBSTITUTE SHEET (RULE 26)Such diseases include tumors, neoplasms and cancer as well as diseases characterized by hyperplastic growth. One of skill in the art can readily identify a chemotherapeutic agent of use (e.g. see Physicians' Cancer Chemotherapy Drug Manual 2014, Edward Chu, Vincent T. De Vita Jr., Jones & Bartlett Learning; Principles of Cancer Therapy, Chapter 85 in Harrison's Principles of Internal Medicine, 18th edition; Therapeutic Targeting of Cancer Cells: Era of Molecularly Targeted Agents and Cancer Pharmacology, Chs. 28-29 in Abeloff s Clinical Oncology, 2013 Elsevier; and Fischer D S (ed): The Cancer Chemotherapy Handbook, 4th ed. St. Louis, Mosby-Year Book, 2003). Exemplary chemotherapeutics include an anthracycline (e.g., doxorubicin (e.g., liposomal doxorubicin)), a vinca alkaloid (e.g., vinblastine, vincristine, vindesine, vinorelbine), an alkylating agent (e.g., cyclophosphamide, decarbazine, melphalan, ifosfamide, temozolomide), an antibody (e.g., alemtuzamab, bevacizumab (Avastin®), gemtuzumab, nivolumab (Opdivo®), pembrolizumab (Keytruda®), rituximab (Rituxan®), traztuzumab (Herceptin®) tositumomab), an antimetabolite (including, e.g., folic acid antagonists, pyrimidine analogs, purine analogs and adenosine deaminase inhibitors (e.g., fludarabine)), an mTOR inhibitor, a TNFR glucocorticoid induced TNFR related protein (GITR) agonist, a proteasome inhibitor (e.g., aclacinomycin A, gliotoxin or bortezomib), an immunomodulator such as thalidomide or a thalidomide derivative (e.g., lenalidomide (Revlimid®)), a kinase inhibitor (e.g., palbociclib (Ibrance®), or a hormone therapy (e.g., abiraterone acetate (Zytiga®)). General chemotherapeutic agents include anastrozole (Arimidex®), bicalutamide (Casodex®), bleomycin sulfate (Blenoxane®), busulfan (Myleran®), busulfan injection (Busulfex®), capecitabine (Xeloda®), N4-pentoxycarbonyl-5- deoxy-5-fluorocytidine, carboplatin (Paraplatin®), carmustine (BiCNU®), chlorambucil (Leukeran®), cisplatin (Platinol®), cladribine (Leustatin®), cyclophosphamide (Cytoxan® or Neosar®), cytarabine, cytosine arabinoside (Cytosar-U®), cytarabine liposome injection (DepoCyt®), dacarbazine (DTIC-Dome®), dactinomycin (Actinomycin D, Cosmegan), daunorubicin hydrochloride (Cerubidine®), daunorubicin citrate liposome injection (DaunoXome®), dexamethasone, docetaxel (Taxotere®), doxorubicin hydrochloride (Adriamycin®, Rubex®), etoposide (Vepesid®, Etopophos®, Toposar®), fludarabine phosphate (Fludara®), 5- fluorouracil (Adrucil®, Efudex®), flutamide (Eulexin®), tezacitibine, gemcitabine (difluorodeoxycitidine), hydroxyurea (Hydrea®), ibrutinib (Imbruvica®), Idarubicin (Idamycin®), ifosfamide (IFEX®), irinotecan (Camptosar®), L-asparaginase (ELSPAR®), leucovorin calcium, melphalan (Alkeran®), 6-mercaptopurine (Purinethol®), methotrexate (Folex®), mitoxantrone (Novantrone®), mylotarg, paclitaxel (Taxol®), phoenix (Yttrium90 / MX-DTPA), pentostatin, polifeprosan 20 with carmustine implant (Gliadel®), tamoxifen citrate (Nolvadex®), teniposide (Vumon®), 6-thioguanine, thiotepa, tirapazamine (Tirazone®), topotecan hydrochloride for injection (Hycamptin®), vinblastine (Velban®), vincristine (Oncovin®), and vinorelbine (Navelbine®). Exemplary alkylating agents include, without limitation, nitrogen mustards, ethylenimine derivatives, alkyl sulfonates, nitrosoureas and triazenes): uracil mustard (Aminouracil Mustard®,18SUBSTITUTE SHEET (RULE 26)Chlorethaminacil®, Demethyldopan®, Desmethyldopan®, Haemanthamine®, Nordopan®, Uracil nitrogen mustard®, Uracillost®, Uracilmostaza®, Uramustin®, Uramustine®), chlormethine (Mustargen®), cyclophosphamide (Cytoxan®, Neosar®, Clafen®, Endoxan®, Procytox®, Revimmune™), ifosfamide (Mitoxana®), melphalan (Alkeran®), Chlorambucil (Leukeran®), pipobroman (Amedel®, Vercyte®), triethylenemelamine (Hemel®, Hexalen®, Hexastat®), triethylenethiophosphoramine, Temozolomide (Temodar®), thiotepa (Thioplex®, Tepadina®), busulfan (Busilvex®, Myleran®), improsulfan, piposulfan, carmustine (BiCNU®), lomustine (CeeNU®), streptozocin (Zanosar®), and Dacarbazine (DTIC-Dome®). Additional exemplary alkylating agents include, without limitation, Oxaliplatin (Eloxatin®); Temozolomide (Temodar® and Temodal®); Dactinomycin (also known as actinomycin-D, Cosmegen®); Melphalan (also known as L-PAM, L-sarcolysin, and phenylalanine mustard, Alkeran®); Altretamine (also known as hexamethylmelamine (HMM), Hexalen®); Carmustine (BiCNU®); Bendamustine (Treanda®); Busulfan (Busulfex® and Myleran®); carboplatin (Paraplatin®); Lomustine (also known as CCNU, CeeNU®); Cisplatin (also known as CDDP, Platinol® and Platinol®-AQ); Chlorambucil (Leukeran®); Cyclophosphamide (Cytoxan® and Neosar®); Dacarbazine (also known as DTIC, DIC and imidazole carboxamide, DTIC-Dome®); Altretamine (also known as hexamethylmelamine (HMM), Hexalen®); Ifosfamide (Ifex®); Prednumustine; Procarbazine (Matulane®);Mechlorethamine (also known as nitrogen mustard, mustine and mechloroethamine hydrochloride, Mustargen®); Streptozocin (Zanosar®); Thiotepa (also known as thiophosphoamide, TESPA and TSP A, Thioplex®); Cyclophosphamide (Endoxan®, Cytoxan®, Neosar®, Procytox®, Revimmune®); and Bendamustine HC1 (Treanda®). Exemplary mTOR inhibitors include, e.g., temsirolimus; ridaforolimus (formally known as deferolimus, (lR,2R,45)-4-[(2R)-2 [(lR,95,125,15R,16E,18R,19R,21R,235,24E,26E,28Z,305,325,35R)-l,18-dihydroxy-19,30- dimethoxy-15, 17,21,23, 29,35- hexamethyl-2,3,10,14,20-pentaoxo-l l,36-dioxa-4- azatricyclo[30.3.1.04'9] hexatriaconta- 16, 24, 26, 28-tetraen-12-yl]propyl]-2 -methoxycyclohexyl dimethylphosphinate, also known as AP23573 and MK8669, and described in PCT Publication No. WO 03 / 064383); everolimus (Afmitor® or RADOO1); rapamycin (AY22989, Sirolimus®); simapimod (CAS 164301-51-3); emsirolimus, (5-{2,4-Bis[(35,)-3-methylmorpholin-4-yl]pyrido[2,3- (i]pyrimidin-7-yl}-2- methoxyphenyl)methanol (AZD8055); 2-Amino-8-[iraw5,-4-(2- hydroxyethoxy)cyclohexyl]-6- (6-methoxy-3-pyridinyl)-4-methyl-pyrido[2,3-JJpyrimidin-7(8H)-one (PF04691502, CAS 1013101-36-4); andN2-[l,4-dioxo-4-[[4-(4-oxo-8-phenyl-4H-l-benzopyran-2- yl)morpholinium-4-yl]methoxy]butyl]-L-arginylglycyl-L-a-aspartylL-serine-, inner salt (SF1126, CAS 936487-67-1), and XL765. Exemplary immunomodulators include, e.g., afutuzumab (available from Roche®); pegfilgrastim (Neulasta®); lenalidomide (CC-5013, Revlimid®); thalidomide (Thalomid®), actimid (CC4047); and IRX-2 (mixture of human cytokines including interleukin 1, interleukin 2, and interferon y, CAS 951209-71-5, available from IRX Therapeutics). Exemplary19SUBSTITUTE SHEET (RULE 26)anthracyclines include, e.g., doxorubicin (Adriamycin® and Rubex®); bleomycin (lenoxane®); daunorubicin (dauorubicin hydrochloride, daunomycin, and rubidomycin hydrochloride, Cerubidine®); daunorubicin liposomal (daunorubicin citrate liposome, DaunoXome®); mitoxantrone (DHAD, Novantrone®); epirubicin (Ellence™); idarubicin (Idamycin®, Idamycin PFS®); mitomycin C (Mutamycin®); geldanamycin; herbimycin; ravidomycin; and desacetylravidomycin. Exemplary vinca alkaloids include, e.g., vinorelbine tartrate (Navelbine®), Vincristine (Oncovin®), and Vindesine (Eldisine®)); vinblastine (also known as vinblastine sulfate, vincaleukoblastine and VLB, Alkaban-AQ® and Velban®); and vinorelbine (Navelbine®). Exemplary proteosome inhibitors include bortezomib (Velcade®); carfdzomib (PX- 171-007, (5)-4-Methyl-N-((5)-l-(((5)-4-methyl-l- ((R)-2-methyloxiran-2-yl)-l-oxopentan-2- yl)amino)-l -oxo-3 -phenylpropan-2-y l)-2-((5,)-2-(2- morpholinoacetamido)-4- phenylbutanamido)-pentanamide); marizomib (NPT0052); ixazomib citrate (MLN-9708); delanzomib (CEP-18770); and O-Methyl-N-[(2-methyl-5-thiazolyl)carbonyl]-L-seryl- 0- methyl-N-[(HS')-2-[(2R)-2-methyl-2-oxiranyl]-2-oxo-l-(phenylmethyl)ethyl]- L-serinamide (ONX- 0912). Additional exemplary anti-cancer agents also include AMG479, vorinostat, ABT-737, PI- 103; aziridines such as benzodopa, carboquone, meturedopa, and uredopa; ethylenimines and methylamelamines including altretamine, triethylenemelamine, trietylenephosphoramide, triethiylenethiophosphoramide and trimethylolomelamine; acetogenins (especially bullatacin and bullatacinone); a camptothecin (including the synthetic analogue topotecan); bryostatin; callystatin; CC-1065 (including its adozelesin, carzelesin and bizelesin synthetic analogues); cryptophycins (particularly cryptophycin 1 and cryptophycin 8); dolastatin; duocarmycin (including the synthetic analogues, KW-2189 and CB1-TM1); eleutherobin; pancratistatin; a sarcodictvin: spongistatin; nitrogen mustards such as chlorambucil, chlornaphazine, cholophosphamide, estramustine, ifosfamide, mechlorethamine, mechlorethamine oxide hydrochloride, melphalan, novembichin, phenesterine, prednimustine, trofosfamide, uracil mustard; nitrosureas such as carmustine, chlorozotocin, fotemustine, lomustine, nimustine, and ranimnustine; antibiotics such as the enediyne antibiotics (e.g., calicheamicin, especially calicheamicin gammall and calicheamicin omegall (see, e.g., Agnew, Chem. Inti. Ed. Engl., 33: 183-186 (1994)); dynemicin, including dynemicin A; bisphosphonates, such as clodronate; an esperamicin; as well as neocarzinostatin chromophore and related chromoprotein enediyne antiobiotic chromophores), aclacinomysins, actinomycin, authramycin, azaserine, bleomycins, cactinomycin, carabicin, caminomycin, carzinophilin, chromomycinis, dactinomycin, daunorubicin, detorubicin, 6-diazo-5-oxo-L-norleucine, ADRIAMYCIN® doxorubicin (including morpholino-doxorubicin, cyanomorpholino-doxorubicin, 2- pyrrolino-doxorubicin and deoxy doxorubicin), epirubicin, esorubicin, idarubicin, marcellomycin, mitomycins such as mitomycin C, mycophenolic acid, nogalamycin, olivomycins, peplomycin, potfiromycin, puromycin, quelamycin, rodorubicin, streptonigrin, streptozocin, tubercidin, ubenimex, zinostatin, zorubicin; anti-metabolites such as methotrexate and 5 -fluorouracil (5-FU); folic acid20SUBSTITUTE SHEET (RULE 26)analogues such as denopterin, methotrexate, pteropterin, trimetrexate; purine analogs such as fludarabine, 6-mercaptopurine, thiamiprine, thioguanine; pyrimidine analogs such as ancitabine, azacitidine, 6-azauridine, carmofur, cytarabine, dideoxy uridine, doxifluridine, enocitabine, floxuridine; androgens such as calusterone, dromostanolone propionate, epitiostanol, mepitiostane, testolactone; anti-adrenals such as aminoglutethimide, mitotane, trilostane; folic acid replenisher such as frolinic acid; aceglatone; aldophosphamide glycoside; aminolevulinic acid; eniluracil; amsacrine; bestrabucil; bisantrene; edatraxate; defofamine; demecolcine; diaziquone; elformithine; elliptinium acetate; an epothilone; etoglucid; gallium nitrate; hydroxyurea; lentinan; lonidainine; maytansinoids such as maytansine and ansamitocins; mitoguazone; mitoxantrone; mopidanmol; nitraerine; pentostatin; phenamet; pirarubicin; losoxantrone; podophyllinic acid; 2-ethylhydrazide; procarbazine; PSK® polysaccharide complex (JHS Natural Products, Eugene, Oreg.); razoxane; rhizoxin; sizofuran; spirogermanium; tenuazonic acid; triaziquone; 2,2',2"-trichlorotriethylamine; trichothecenes (especially T-2 toxin, verracurin A, roridin A and anguidine); urethan; vindesine; dacarbazine; mannomustine; mitobronitol; mitolactol; pipobroman; gacytosine; arabinoside ("Ara-C"); cyclophosphamide; thiotepa; taxoids, e.g., TAXOL® paclitaxel (Bristol-Myers Squibb Oncology, Princeton, N.J.), ABRAXANE® Cremophor-free, albumin-engineered nanoparticle formulation of paclitaxel (American Pharmaceutical Partners, Schaumberg, Ill.), and TAXOTERE® doxetaxel (Rhone-Poulenc Rorer, Antony, France); chloranbucil; GEMZAR® gemcitabine; 6-thioguanine; mercaptopurine; methotrexate; platinum analogs such as cisplatin, oxaliplatin and carboplatin; vinblastine; platinum; etoposide (VP-16); ifosfamide; mitoxantrone; vincristine; NAVELBINE.RTM. vinorelbine; novantrone; teniposide; edatrexate; daunomycin; aminopterin; xeloda; ibandronate; irinotecan (Camptosar, CPT-11) (including the treatment regimen of irinotecan with 5-FU and leucovorin); topoisomerase inhibitor RFS 2000; difluoromethylornithine (DMFO); retinoids such as retinoic acid; capecitabine; combretastatin; leucovorin (LV); oxaliplatin, including the oxaliplatin treatment regimen (FOLFOX); lapatinib (Tykerb.RTM.); inhibitors of PKC -alpha, Raf, H-Ras, EGFR (e.g., erlotinib (Tarceva®)) and VEGF-A that reduce cell proliferation.

[0086] Further disclosed herein are methods for dissolving or dissociating a hydrogel or gel structure present in the composition comprising gellan gum. Specifically, the composition comprising gellan gum can be contacted with a dissolution composition to dissolve or dissociate a hydrogel or gel structure. In some embodiments of any of the aspects, the methods described herein can further comprising administering a dissolution composition to the subject after the placement of the composition comprising gellan gum. In some embodiments of any of the aspects, the methods described herein can further comprising administering a dissolution composition to the subject after the administration of an ablation treatment. In some embodiments of any of the aspects, the methods described herein can further comprising administering a dissolution composition to the subject after21SUBSTITUTE SHEET (RULE 26)the placement of the composition comprising gellan gum by injecting the dissolution composition into the composition comprising gellan gum.

[0087] In some embodiments of any of the aspects, the drug is an anti-inflammatory. Exemplary anti-inflammatories include, but are not limited to, non-steroidal anti-inflammatory drugs (NSAIDs - such as aspirin, ibuprofen, or naproxen); corticosteroids, including glucocorticoids (e.g. cortisol, prednisone, prednisolone, methylprednisolone, dexamethasone, betamethasone, triamcinolone, and beclometasone); methotrexate; sulfasalazine; leflunomide; anti-TNF medications; cyclophosphamide; pro-resolving drugs; mycophenolate; opiates (e.g. endorphins, enkephalins, and dynorphin), steroids, analgesics, barbiturates, oxycodone, morphine, lidocaine, and the like. In some embodiments, the antiinflammatory agent can be a steroid (e.g., a corticosteroid or glucocorticoid); a calcineurin inhibitor (e.g. cyclosporine, tacrolimus, pimecrolimus, or FK506); an mTOR inhibitor (e.g., everolimus, temsirolimus, rapamycin, deforolimus, TOP216, OSI-027, TAFA93, nab-rapamycin, tacrolimus, biolimus, CI-779, ABT-578, AP-23675, BEZ-235, QLT-0447, ABI-009, BC-210, salirasib, AP- 23841, AP-23573, KU-0059475, 32-deoxorapamycin, 16-pent-2-ynyloxy-32-deoxorapamycin, 16- pent-2-ynyloxy-32 (S or R)-dihydro-rapamycin, 16-pent-2-ynyloxy-32 (S or R)-dihydro-40-O-(2- hydroxyethylj-rapamycin, 40-O-(2-hydroxyethyl)-rapamycin, 32-deoxorapamycin; 16-pent-2- ynyloxy-32(S)-dihydrorapamycin; socalledrapalogs; AP23464; PI-103, PP242, PP30, Torinl; and derivatives or pharmaceutically acceptable salts thereof as well as and compounds described in, e.g. U.S. Patent Publications 2011 / 0178070; 2011 / 0021515; 2007 / 0112005; 2011 / 0054013; International Patent Publications WO98 / 02441; WOOl / 14387; WO99 / 15530; WO07 / 135411; WO03 / 64383; WO96 / 41807; WO95 / 16691; W094 / 09010; European Patent No. EP1880723; andU.S. Patent Nos. 8,163,775; 6,329,386; 6,200,985; 6,117,863; 6,015,815; 6,015,809; 6,004,973; 5,985,890; 5,955,457; 5,922,730; 5,912,253; 5,780,462; 5,665,772; 5,637,590; 5,567,709; 5,563,145; 5,559,122; 5,559,120; 5,559,119; 5,559,112; 5,550,133; 5,541,192; 5,541,191; 5,532,355; 5,530,121; 5,530,007; 5,525,610; 5,521,194; 5,519,031; 5,516,780; 5,508,399; 5,508,290; 5,508,286; 5,508,285; 5,504,291; 5,504,204; 5,491,231; 5,489,680; 5,489,595; 5,488,054; 5,486,524; 5,486,523; 5,486,522; 5,484,791; 5,484,790; 5,480,989; 5,480,988; 5,463,048; 5,446,048; 5,434,260; 5,411,967; 5,391,730; 5,389,639; 5,385,910; 5,385,909; 5,385,908; 5,378,836; 5,378,696; 5,373,014; 5,362,718; 5,358,944; 5,346,893; 5,344,833; 5,302,584; 5,262,424; 5,262,423; 5,260,300; 5,260,299; 5,233,036; 5,221,740; 5,221,670; 5,202,332; 5,194,447; 5,177,203; 5,169,851; 5,164,399; 5,162,333; 5,151,413; 5,138,051; 5,130,307; 5,120,842; 5,120,727; 5,120,726; 5,120,725; 5,118,678; 5,118,677; 5,100,883; 5,023,264; 5,023,263; and 5,023,262; which are incorporated by reference herein in their entireties.); rapamycin (sirolimus) or an analogue thereof (e.g. everolimus, temsirolimus, ridaforolimus, deforolimus); or an antiproliferative agent (e.g. mycophenoloate moefitil, azathioprine). Anti-proliferative agents can include, by way of non-limiting example, alkylating agents (e.g. cyclophosphamide, platinum compounds, and nitrosoureass), antimetabolites (e.g. methotrexate, azathioprine, mercaptopurine,22SUBSTITUTE SHEET (RULE 26)fluorouracil, etc.), and cytotoxic antibiotics (e.g., dactinomycin, anthracyclines, mitomycin C, bleomycin, and mithramycin).

[0088] In some embodiments of any of the aspects, the dissolution composition comprises one or more of: EDTA; glucose; glutathione; saline; and sodium bicarbonate. In some embodiments of any of the aspects, the dissolution composition comprises EDTA; glucose; glutathione; saline; and sodium bicarbonate. In some embodiments of any of the aspects, the glucose is a 5% w / v glucose solution. In some embodiments of any of the aspects, the glucose is a 2-4% glucose solution. In some embodiments of any of the aspects, the glucose is a 4-6% glucose solution. In some embodiments of any of the aspects, the glucose is a 5% glucose solution. In some embodiments of any of the aspects, the saline is a normal saline solution (e.g., 0.9% w / v NaCl).

[0089] In some embodiments of any of the aspects, the subject is not administered hydrodissection comprising or consisting of saline injection or dextrose solution injection. In some embodiments of any of the aspects, the subject is not administered a saline injection. In some embodiments of any of the aspects, the subject is not administered a dextrose solution injection. In some embodiments of any of the aspects, the subject is not administered a saline injection or a dextrose solution injection at the location of the placement of the composition comprising gellan gum.

[0090] In some embodiments of any of the aspects, the subject is not administered hydrodissection comprising or consisting of polyethylene glycol (PEG), collagen, pluronic 407, or hyaluronic acid. In some embodiments of any of the aspects, the subject is not administered hydrodissection comprising one or more of polyethylene glycol (PEG), collagen, pluronic 407, and hyaluronic acid and not comprising gellan gum. In some embodiments of any of the aspects, the subject is not administered, at the location of the placement of the composition comprising gellan gum, an injection comprising or consisting of polyethylene glycol (PEG), collagen, pluronic 407, or hyaluronic acid. In some embodiments of any of the aspects, the subject is not administered, at the location of the placement of the composition comprising gellan gum, an injection comprising one or more of polyethylene glycol (PEG), collagen, pluronic 407, and hyaluronic acid and not comprising gellan gum.

[0091] In some embodiments of any of the aspects, the composition comprising gellan gum does not comprise polyethylene glycol (PEG), collagen, poloxamer 407, or hyaluronic acid. In some embodiments of any of the aspects, the composition comprising gellan gum does not comprise polyethylene glycol (PEG). In some embodiments of any of the aspects, the composition comprising gellan gum does not comprise collagen. In some embodiments of any of the aspects, the composition comprising gellan gum does not comprise poloxamer 407. In some embodiments of any of the aspects, the composition comprising gellan gum does not comprise hyaluronic acid.

[0092] In some embodiments, the methods described herein relate to treating a subject having or diagnosed as having condition described herein. Methods of identifying the conditions described23SUBSTITUTE SHEET (RULE 26)herein are well known in the art. The compositions and methods described herein can be administered to a subject having or diagnosed as having a condition described herein. In some embodiments, the methods described herein comprise administering an effective amount of compositions described herein, e.g. a composition comprising gellan gum to a subject in order to effectively create space between a target and non-target, e.g., that will reduce the exposure of the non-target to a treatment administered to the target. As compared with an equivalent untreated control, such reduction is by at least 5%, 10%, 20%, 40%, 50%, 60%, 80%, 90%, 95%, 99% or more as measured by any standard technique.

[0093] In embodiments relating to administration of a drug or treatment, an effective amount can be administered. The term “effective amount" as used herein refers to the amount of the drug or treatment needed to alleviate at least one or more symptom of the disease or disorder (e.g.,. a reduction of one or more symptoms), and / or relates to a sufficient amount of pharmacological composition to provide the desired effect. As compared with an equivalent untreated control, such reduction is by at least 5%, 10%, 20%, 40%, 50%, 60%, 80%, 90%, 95%, 99% or more as measured by any standard technique. The term "therapeutically effective amount" therefore refers to an amount of a drug or treatment that is sufficient to provide a particular therapeutic effect when administered to a typical subject. An effective amount as used herein, in various contexts, would also include an amount sufficient to delay the development of a symptom of the disease, alter the course of a symptom disease (for example but not limited to, slowing the progression of a symptom of the disease), or reverse a symptom of the disease. Thus, it is not generally practicable to specify an exact “effective amount". However, for any given case, an appropriate “effective amount" can be determined by one of ordinary skill in the art using only routine experimentation.

[0094] Effective amounts, toxicity, and therapeutic efficacy can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, e.g., for determining the LD50 (the dose lethal to 50% of the population) and the ED50 (the dose therapeutically effective in 50% of the population). The dosage can vary depending upon the dosage form employed and the route of administration utilized. The dose ratio between toxic and therapeutic effects is the therapeutic index and can be expressed as the ratio LD50 / ED50. Compositions and methods that exhibit large therapeutic indices are preferred. A therapeutically effective dose can be estimated initially from cell culture assays. Also, a dose can be formulated in animal models to achieve a circulating plasma concentration range that includes the IC50 (i.e., the concentration of an active agent which achieves a half-maximal inhibition of symptoms) as determined in cell culture, or in an appropriate animal model. Levels in plasma can be measured, for example, by high performance liquid chromatography. The effects of any particular dosage can be monitored by a suitable bioassay. The dosage can be determined by a physician and adjusted, as necessary, to suit observed effects of the treatment.24SUBSTITUTE SHEET (RULE 26)

[0095] In some embodiments, the technology described herein relates to a pharmaceutical composition comprising a composition comprising gellan gum as described herein, and optionally a pharmaceutically acceptable carrier. In some embodiments, the ingredients of the pharmaceutical composition comprise a composition comprising gellan gum as described herein. In some embodiments, the ingredients of the pharmaceutical composition consist essentially of a composition comprising gellan gum as described herein. In some embodiments, the ingredients of the pharmaceutical composition consist of a composition comprising gellan gum as described herein.

[0096] Pharmaceutically acceptable carriers and diluents include saline, aqueous buffer solutions, solvents and / or dispersion media. The use of such carriers and diluents is well known in the art. Some non-limiting examples of materials which can serve as pharmaceutically-acceptable carriers include: (1) sugars, such as lactose, glucose and sucrose; (2) starches, such as corn starch and potato starch; (3) cellulose, and its derivatives, such as sodium carboxymethyl cellulose, methylcellulose, ethyl cellulose, microcrystalline cellulose and cellulose acetate; (4) powdered tragacanth; (5) malt; (6) gelatin; (7) lubricating agents, such as magnesium stearate, sodium lauryl sulfate and talc; (8) excipients, such as cocoa butter and suppository waxes; (9) oils, such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, com oil and soybean oil; (10) glycols, such as propylene glycol; (11) polyols, such as glycerin, sorbitol, mannitol and polyethylene glycol (PEG); (12) esters, such as ethyl oleate and ethyl laurate; (13) agar; (14) buffering agents, such as magnesium hydroxide and aluminum hydroxide; (15) alginic acid; (16) pyrogen-free water; (17) isotonic saline; (18) Ringer's solution; (19) ethyl alcohol; (20) pH buffered solutions; (21) polyesters, polycarbonates and / or polyanhydrides; (22) bulking agents, such as polypeptides and amino acids (23) serum component, such as serum albumin, HDL and LDL; (22) C2-C12 alcohols, such as ethanol; and (23) other nontoxic compatible substances employed in pharmaceutical formulations. Wetting agents, coloring agents, release agents, coating agents, sweetening agents, flavoring agents, perfuming agents, preservative and antioxidants can also be present in the formulation. The terms such as "excipient", "earner", "pharmaceutically acceptable carrier" or the like are used interchangeably herein.

[0097] In some embodiments, the composition comprising gellan gum as described herein can be a parenteral dose form. Since administration of parenteral dosage forms typically bypasses the patient's natural defenses against contaminants, parenteral dosage forms are preferably sterile or capable of being sterilized prior to administration to a patient. Examples of parenteral dosage forms include, but are not limited to, solutions ready for injection, dry products ready to be dissolved or suspended in a pharmaceutically acceptable vehicle for injection, suspensions ready for injection, and emulsions.

[0098] Suitable vehicles that can be used to provide parenteral compositions as disclosed within are well known to those skilled in the art. Examples include, without limitation: sterile water; water for injection USP; saline solution; glucose solution; aqueous vehicles such as but not limited to, sodium chloride injection, Ringer's injection, dextrose Injection, dextrose and sodium chloride injection, and25SUBSTITUTE SHEET (RULE 26)lactated Ringer's injection; water -miscible vehicles such as, but not limited to, ethyl alcohol, polyethylene glycol, and propylene glycol; and non-aqueous vehicles such as, but not limited to, corn oil, cottonseed oil, peanut oil, sesame oil, ethyl oleate, isopropyl myristate, and benzyl benzoate. Compounds that alter or modify the solubility of gellan gum as disclosed herein can also be incorporated into the parenteral dosage forms of the disclosure, including conventional and controlled-release parenteral dosage forms.

[0099] In certain embodiments, a composition comprising gellan gum as described herein can be administered to a patient once. In certain embodiments, a composition comprising gellan gum as as described herein can be administered to a patient repeatedly.

[0100] The dosage or volume of a composition as described herein can be determined by a physician and adjusted, as necessary, to suit observed effects of the treatment.

[0101] In embodiments relating to a drug, with respect to duration and frequency of treatment, it is typical for skilled clinicians to monitor subjects in order to determine when the treatment is providing therapeutic benefit, and to determine whether to increase or decrease dosage, increase or decrease administration frequency, discontinue treatment, resume treatment, or make other alterations to the treatment regimen. The dosing schedule can vary from once a week to daily depending on a number of clinical factors, such as the subject's sensitivity to the drug. The desired dose or amount of activation can be administered at one time or divided into subdoses, e.g., 2-4 subdoses and administered over a period of time, e.g., at appropriate intervals through the day or other appropriate schedule. In some embodiments, administration can be chronic, e.g., one or more doses and / or treatments daily over a period of weeks or months. Examples of dosing and / or treatment schedules are administration daily, twice daily, three times daily or four or more times daily over a period of 1 week, 2 weeks, 3 weeks, 4 weeks, 1 month, 2 months, 3 months, 4 months, 5 months, or 6 months, or more. A composition can be administered over a period of time, such as over a 5 minute, 10 minute, 15 minute, 20 minute, or 25 minute period.

[0102] The efficacy of a composition described herein in, e.g. the treatment of a condition described herein, or to induce a response as described herein (e.g. insulation or protection of a non-target) can be determined by the skilled clinician. However, a treatment is considered “effective treatment," as the term is used herein, if one or more of the signs or symptoms of a condition described herein are altered in a beneficial manner, other clinically accepted symptoms are improved, or even ameliorated, or a desired response or effect is induced e.g., by at least 10% following treatment according to the methods described herein. Efficacy can be assessed, for example, by measuring a marker, indicator, symptom, and / or the incidence of a condition treated according to the methods described herein or any other measurable parameter appropriate, e.g. the degree of insulation provided to a non-target. Efficacy can also be measured by a failure of an individual to worsen as assessed by hospitalization, or need for medical interventions (i.e., progression of the disease is halted). Methods of measuring26SUBSTITUTE SHEET (RULE 26)these indicators are known to those of skill in the art and / or are described herein. Treatment includes any treatment of a disease in an individual or an animal (some non-limiting examples include a human or an animal) and includes: (1) inhibiting the disease, e.g., preventing a worsening of symptoms (e.g. pain or inflammation); or (2) relieving the severity of the disease, e.g., causing regression of symptoms. An effective amount for the treatment of a disease means that amount which, when administered to a subject in need thereof, is sufficient to result in effective treatment as that term is defined herein, for that disease. Efficacy of an agent can be determined by assessing physical indicators of a condition or desired response. It is well within the ability of one skilled in the art to monitor efficacy of administration and / or treatment by measuring any one of such parameters, or any combination of parameters. Efficacy can be assessed in animal models of a condition described herein, for example ablation and hydrodissection models. When using an experimental animal model, efficacy of treatment is evidenced when a statistically significant change in a marker is observed, e.g. degree of insulation or separation.

[0103] In one respect, the present invention relates to the herein described compositions, methods, and respective component(s) thereof, as essential to the technology, yet open to the inclusion of unspecified elements, essential or not ("comprising). In some embodiments of any of the aspects, other elements to be included in the description of the composition, method or respective component thereof are limited to those that do not materially affect the basic and novel characteristic (s) of the technology (e.g., the composition, method, or respective component thereof “consists essentially of’ the elements described herein). This applies equally to steps within a described method as well as compositions and components therein. In other embodiments of any of the aspects, the compositions, methods, and respective components thereof, described herein are intended to be exclusive of any element not deemed an essential element to the component, composition or method (e.g., the composition, method, or respective component thereof “consists of’ the elements described herein). This applies equally to steps within a described method as well as compositions and components therein.

[0104] For convenience, the meaning of some terms and phrases used in the specification, examples, and appended claims, are provided below. Unless stated otherw ise, or implicit from context, the following terms and phrases include the meanings provided below. The definitions are provided to aid in describing particular embodiments, and are not intended to limit the claimed invention, because the scope of the invention is limited only by the claims. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. If there is an apparent discrepancy between the usage of a term in the art and its definition provided herein, the definition provided within the specification shall prevail.27SUBSTITUTE SHEET (RULE 26)

[0105] For convenience, certain terms employed herein, in the specification, examples and appended claims are collected here.

[0106] The terms “decrease”, “reduced”, “reduction”, or “inhibit” are all used herein to mean a decrease by a statistically significant amount. In some embodiments, “reduce,” “reduction" or “decrease" or “inhibit” typically means a decrease by at least 10% as compared to a reference level (e.g. the absence of a given treatment or agent) and can include, for example, a decrease by at least about 10%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98%, at least about 99% , or more. As used herein,“reduction” or “inhibition” does not encompass a complete inhibition or reduction as compared to a reference level. “Complete inhibition” is a 100% inhibition as compared to a reference level. A decrease can be preferably down to a level accepted as within the range of normal for an individual without a given condition. In the context of a marker, effect, or symptom, a “decrease” is a statistically significant decrease in such level.

[0107] The terms “increased”, “increase”, “enhance”, or “activate” are all used herein to mean an increase by a statically significant amount. In some embodiments, the terms “increased”, “increase”, “enhance”, or “activate” can mean an increase of at least 10% as compared to a reference level, for example an increase of at least about 20%, or at least about 30%, or at least about 40%, or at least about 50%, or at least about 60%, or at least about 70%, or at least about 80%, or at least about 90% or up to and including a 100% increase or any increase between 10-100% as compared to a reference level, or at least about a 2-fold, or at least about a 3-fold, or at least about a 4-fold, or at least about a 5-fold or at least about a 10-fold increase, or any increase between 2-fold and 10-fold or greater as compared to a reference level. In the context of a marker, effect, or symptom, an “increase” is a statistically significant increase in such level.

[0108] As used herein, a "subject" means a human or animal. Usually the animal is a vertebrate such as a primate, rodent, domestic animal or game animal. Primates include chimpanzees, cynomolgus monkeys, spider monkeys, and macaques, e.g., Rhesus. Rodents include mice, rats, woodchucks, ferrets, rabbits and hamsters. Domestic and game animals include cows, horses, pigs, deer, bison, buffalo, feline species, e.g., domestic cat, canine species, e.g., dog, fox, wolf, avian species, e.g., chicken, emu, ostrich, and fish, e.g., trout, catfish and salmon. In some embodiments, the subject is a mammal, e.g., a primate, e.g., a human. The terms, “individual,” “patient” and “subject” are used interchangeably herein.

[0109] Preferably, the subject is a mammal. The mammal can be a human, non-human primate, mouse, rat, dog, cat, horse, or cow, but is not limited to these examples. Mammals other than28SUBSTITUTE SHEET (RULE 26)humans can be advantageously used as subjects that represent animal models of a condition described herein. A subject can be male or female.

[0110] A subject can be one who has been previously diagnosed with or identified as suffering from or having a condition in need of treatment or one or more complications related to such a condition, and optionally, have already undergone treatment for the condition or the one or more complications related to the condition. Alternatively, a subject can also be one who has not been previously diagnosed as having the condition or one or more complications related to the condition. For example, a subject can be one who exhibits one or more risk factors for the condition or one or more complications related to the condition or a subject who does not exhibit risk factors.

[0111] A “subject in need” of treatment for a particular condition can be a subject having that condition, diagnosed as having that condition, or at risk of developing that condition.

[0112] As used herein, the term “hydrogel” refers to a three-dimensional polymeric structure that is insoluble in water but which is capable of absorbing and retaining large quantities of water to form a stable, often soft and pliable, structure. In some embodiments of any of the aspects, water can penetrate in between the polymer chains of the polymer network, subsequently causing swelling and the formation of a hydrogel. In general, hydrogels are superabsorbent. Hydrogels have many desirable properties for biomedical applications. For example, they can be made nontoxic and compatible with tissue, and they are highly permeable to water, ions, and small molecules.

[0113] In some embodiments of any of the aspects, the composition comprising gellan gum described herein is exogenous. In some embodiments of any of the aspects, the composition comprising gellan gum described herein is ectopic. In some embodiments of any of the aspects, the composition comprising gellan gum described herein is not endogenous.

[0114] The term "exogenous" refers to a substance present in a cell other than its native source. The term "exogenous" when used herein can refer to composition that has been introduced by a process involving the hand of man into a biological system such as an organism in which it is not normally found. Alternatively, “exogenous” can refer to a composition that has been introduced by a process involving the hand of man into a biological system such as an organism in which it is found in relatively low amounts and one wishes to increase the amount of the composition in the organism, e.g., to create ectopic expression or levels. In contrast, the term "endogenous" refers to a substance that is native to the biological system. As used herein, “ectopic” refers to a substance that is found in an unusual location and / or amount. An ectopic substance can be one that is normally found in a given organism, but at a much lower amount and / or at a different time. Ectopic also includes substance that is not naturally found or expressed in a given organism in its natural environment.

[0115] As used herein, the terms "treat,” "treatment," "treating,” or “amelioration” refer to therapeutic treatments, wherein the object is to reverse, alleviate, ameliorate, inhibit, slow down or stop the progression or severity of a condition described herein. The term “treating" includes reducing29SUBSTITUTE SHEET (RULE 26)or alleviating at least one adverse effect or symptom of a condition, disease or disorder associated with a condition described herein. Treatment is generally “effective" if one or more symptoms or clinical markers are reduced. Alternatively, treatment is “effective" if the progression of a disease is reduced or halted. That is, “treatment" includes not just the improvement of symptoms or markers, but also a cessation of, or at least slowing of, progress or worsening of symptoms compared to what would be expected in the absence of treatment. Beneficial or desired clinical results include, but are not limited to, alleviation of one or more symptom(s), diminishment of extent of disease, stabilized ( / .e., not worsening) state of disease, delay or slowing of disease progression, amelioration or palliation of the disease state, remission (whether partial or total), and / or decreased mortality, whether detectable or undetectable. The term "treatment" of a disease also includes providing relief from the symptoms or side-effects of the disease (including palliative treatment).

[0116] In some embodiments of any of the aspects, described herein is a prophylactic method of treatment. As used herein “prophylactic” refers to the timing and intent of a treatment relative to a disease or symptom, that is, the treatment is administered prior to clinical detection or diagnosis of that particular disease or symptom in order to protect the patient from the disease or symptom. Prophylactic treatment can encompass a reduction in the severity or speed of onset of the disease or symptom, or contribute to faster recovery from the disease or symptom. Accordingly, the methods described herein can be prophylactic relative to an ablation treatment, excision treatment, or use of a device or material described herein. In some embodiments of any of the aspects, prophylactic treatment is not prevention of all symptoms or signs of a disease.

[0117] As used herein, the term “pharmaceutical composition” refers to the active agent in combination with a pharmaceutically acceptable carrier e.g. a carrier commonly used in the pharmaceutical industry. The phrase "pharmaceutically acceptable" is employed herein to refer to those compounds, materials, compositions, and / or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit / risk ratio. In some embodiments of any of the aspects, a pharmaceutically acceptable carrier can be a carrier other than water. In some embodiments of any of the aspects, a pharmaceutically acceptable carrier can be a cream, emulsion, gel, liposome, nanoparticle, and / or ointment. In some embodiments of any of the aspects, a pharmaceutically acceptable carrier can be an artificial or engineered carrier, e.g., a carrier that the active ingredient would not be found to occur in in nature.

[0118] As used herein, the term "administering," refers to the placement of a compound as disclosed herein into a subject by a method or route which results in at least partial delivery of the agent at a desired site. Pharmaceutical compositions comprising the compounds disclosed herein can be administered by any appropriate route which results in an effective treatment in the subject. In30SUBSTITUTE SHEET (RULE 26)some embodiments, administration comprises physical human activity, e.g., an injection, act of ingestion, an act of application, and / or manipulation of a delivery device or machine. Such activity can be performed, e.g., by a medical professional and / or the subject being treated.

[0119] As used herein, “contacting" refers to any suitable means for delivering, or exposing, an agent to at least one cell. Exemplary delivery methods include, but are not limited to, direct delivery to cell culture medium, perfusion, injection, or other delivery method well known to one skilled in the art. In some embodiments, contacting comprises physical human activity, e.g., an injection; an act of dispensing, mixing, and / or decanting; and / or manipulation of a delivery device or machine.

[0120] As used herein, the term “cancer” relates generally to a class of diseases or conditions in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

[0121] In some embodiments of any of the aspects, the cancer is a primary cancer. In some embodiments of any of the aspects, the cancer is a malignant cancer. As used herein, the term “malignant” refers to a cancer in which a group of tumor cells display one or more of uncontrolled growth (i.e., division beyond normal limits), invasion (i.e., intrusion on and destruction of adjacent tissues), and metastasis (i.e., spread to other locations in the body via lymph or blood). As used herein, the term “metastasize” refers to the spread of cancer from one part of the body to another. A tumor formed by cells that have spread is called a “metastatic tumor” or a “metastasis.” The metastatic tumor contains cells that are like those in the original (primary) tumor. As used herein, the term “benign” or “non-malignanf ’ refers to tumors that may grow larger but do not spread to other parts of the body. Benign tumors are self-limited and typically do not invade or metastasize.

[0122] A “cancer cell” or “tumor cell” refers to an individual cell of a cancerous growth or tissue. A tumor refers generally to a swelling or lesion formed by an abnormal growth of cells, which may be benign, pre -malignant, or malignant. Most cancer cells form tumors, but some, e.g., leukemia, do not necessarily form tumors. For those cancer cells that form tumors, the terms cancer (cell) and tumor (cell) are used interchangeably.

[0123] As used herein the term "neoplasm" refers to any new and abnormal growth of tissue, e.g., an abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the normal tissues. Thus, a neoplasm can be a benign neoplasm, premalignant neoplasm, or a malignant neoplasm.31SUBSTITUTE SHEET (RULE 26)

[0124] A subject that has a cancer or a tumor is a subject having objectively measurable cancer cells present in the subject’s body. Included in this definition are malignant, actively proliferative cancers, as well as potentially dormant tumors or micrometastatses. Cancers which migrate from their original location and seed other vital organs can eventually lead to the death of the subject through the functional deterioration of the affected organs.

[0125] Examples of cancer include but are not limited to, carcinoma, lymphoma, blastoma, sarcoma, leukemia, basal cell carcinoma, biliary tract cancer; bladder cancer; bone cancer; brain and CNS cancer; breast cancer; cancer of the peritoneum; cervical cancer; choriocarcinoma; colon and rectum cancer; connective tissue cancer; cancer of the digestive system; endometrial cancer; esophageal cancer; eye cancer; cancer of the head and neck; gastric cancer (including gastrointestinal cancer); glioblastoma (GBM); hepatic carcinoma; hepatoma; intra-epithelial neoplasm.; kidney or renal cancer; larynx cancer; leukemia; liver cancer; lung cancer (e.g., small -cell lung cancer, nonsmall cell lung cancer, adenocarcinoma of the lung, and squamous carcinoma of the lung); lymphoma including Hodgkin’s and non-Hodgkin’s lymphoma; melanoma; myeloma; neuroblastoma; oral cavity cancer (e.g, lip, tongue, mouth, and pharynx); ovarian cancer; pancreatic cancer; prostate cancer; retinoblastoma; rhabdomyosarcoma; rectal cancer; cancer of the respiratory system; salivary gland carcinoma; sarcoma; skin cancer; squamous cell cancer; stomach cancer; testicular cancer; thyroid cancer; uterine or endometrial cancer; cancer of the urinary system; vulval cancer; as well as other carcinomas and sarcomas; as well as B-cell lymphoma (including low grade / follicular non-Hodgkin’s lymphoma (NHL); small lymphocytic (SL) NHL; intermediate grade / follicular NHL; intermediate grade diffuse NHL; high grade immunoblastic NHL; high grade lymphoblastic NHL; high grade small non-cleaved cell NHL; bulky disease NHL; mantle cell lymphoma; AIDS-related lymphoma; and Waldenstrom’s Macroglobulinemia); chronic lymphocytic leukemia (CLL); acute lymphoblastic leukemia (ALL); Hairy cell leukemia; chronic myeloblastic leukemia; and post-transplant lymphoproliferative disorder (PTLD), as well as abnormal vascular proliferation associated with phacomatoses, edema (such as that associated with brain tumors), and Meigs’ syndrome

[0126] A “cancer cell” is a cancerous, pre-cancerous, or transformed cell, either in vivo, ex vivo, or in tissue culture, that has spontaneous or induced phenotypic changes that do not necessarily involve the uptake of new genetic material. Although transformation can arise from infection with a transforming virus and incorporation of new genomic nucleic acid, or uptake of exogenous nucleic acid, it can also arise spontaneously or following exposure to a carcinogen, thereby mutating an endogenous gene. Transformation / cancer is associated with, e.g. , morphological changes, immortalization of cells, aberrant growth control, foci formation, anchorage independence, malignancy, loss of contact inhibition and density limitation of grow th, growth factor or serum independence, tumor specific markers, invasiveness or metastasis, and tumor growth in suitable animal hosts such as nude mice.32SUBSTITUTE SHEET (RULE 26)

[0127] The term “statistically significant" or “significantly" refers to statistical significance and generally means a two standard deviation (2SD) or greater difference.

[0128] Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients or reaction conditions used herein should be understood as modified in all instances by the term “about.” The term “about” when used in connection with percentages can mean ±1%.

[0129] As used herein, the term “comprising” means that other elements can also be present in addition to the defined elements presented. The use of “comprising” indicates inclusion rather than limitation.

[0130] The term "consisting of refers to compositions, methods, and respective components thereof as described herein, which are exclusive of any element not recited in that description of the embodiment.

[0131] As used herein the term "consisting essentially of refers to those elements required for a given embodiment. The term permits the presence of additional elements that do not materially affect the basic and novel or functional characteristic(s) of that embodiment of the invention.

[0132] The singular terms "a," "an," and "the" include plural referents unless context clearly indicates otherwise. Similarly, the word "or" is intended to include "and" unless the context clearly indicates otherwise. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of this disclosure, suitable methods and materials are described below. The abbreviation, "e.g." is derived from the Latin exempli gratia, and is used herein to indicate a non-limiting example. Thus, the abbreviation "e.g." is synonymous with the term "for example."

[0133] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and / or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

[0134] Unless otherwise defined herein, scientific and technical terms used in connection with the present application shall have the meanings that are commonly understood by those of ordinary skill in the art to which this disclosure belongs. It should be understood that this invention is not limited to the particular methodology, protocols, and reagents, etc., described herein and as such can vary. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention, which is defined solely by the claims. Definitions of common terms in immunology and molecular biology can be found in The Merck Manual of Diagnosis and Therapy, 20th Edition, published by Merck Sharp & Dohme Corp., 201833SUBSTITUTE SHEET (RULE 26)(ISBN 0911910190, 978-0911910421); Robert S. Porter et al. (eds.), The Encyclopedia of Molecular Cell Biology and Molecular Medicine, published by Blackwell Science Ltd., 1999-2012 (ISBN 9783527600908); and Robert A. Meyers (ed.), Molecular Biology and Biotechnology: a Comprehensive Desk Reference, published by VCH Publishers, Inc., 1995 (ISBN 1-56081-569-8); Immunology by Werner Luttmann, published by Elsevier, 2006; Janeway's Immunobiology, Kenneth Murphy, Allan Mowat, Casey Weaver (eds.), W. W. Norton & Company, 2016 (ISBN 0815345054, 978-0815345053); Lewin's Genes XI, published by Jones & Bartlett Publishers, 2014 (ISBN- 1449659055); Michael Richard Green and Joseph Sambrook, Molecular Cloning: A Laboratory Manual, 4th ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., USA (2012) (ISBN 1936113414); Davis et al., Basic Methods in Molecular Biology , Elsevier Science Publishing, Inc., New York, USA (2012) (ISBN 044460149X); Laboratory Methods in Enzymology: DNA, Jon Lorsch (ed.) Elsevier, 2013 (ISBN 0124199542); Cunent Protocols in Molecular Biology (CPMB), Frederick M. Ausubel (ed.), John Wiley and Sons, 2014 (ISBN 047150338X, 9780471503385), Current Protocols in Protein Science (CPPS), John E. Coligan (ed.), John Wiley and Sons, Inc., 2005; and Current Protocols in Immunology (CPI) (John E. Coligan, ADA M Kruisbeek, David H Margulies, Ethan M Shevach, Warren Strobe, (eds.) John Wiley and Sons, Inc., 2003 (ISBN 0471142735, 9780471142737), the contents of which are all incorporated by reference herein in their entireties.

[0135] Other terms are defined herein within the description of the various aspects of the invention.

[0136] All patents and other publications; including literature references, issued patents, published patent applications, and co-pending patent applications; cited throughout this application are expressly incorporated herein by reference for the purpose of describing and disclosing, for example, the methodologies described in such publications that might be used in connection with the technology described herein. These publications are provided solely for their disclosure prior to the filing date of the present application. Nothing in this regard should be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention or for any other reason. All statements as to the date or representation as to the contents of these documents is based on the information available to the applicants and does not constitute any admission as to the correctness of the dates or contents of these documents.

[0137] The description of embodiments of the disclosure is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. While specific embodiments of, and examples for, the disclosure are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the disclosure, as those skilled in the relevant art will recognize. For example, while method steps or functions are presented in a given order, alternative embodiments may perform functions in a different order, or functions may be performed substantially concurrently. The teachings of the disclosure provided herein can be applied to other procedures or methods as34SUBSTITUTE SHEET (RULE 26)appropriate. The various embodiments described herein can be combined to provide further embodiments. Aspects of the disclosure can be modified, if necessary, to employ the compositions, functions and concepts of the above references and application to provide yet further embodiments of the disclosure. These and other changes can be made to the disclosure in light of the detailed description. All such modifications are intended to be included within the scope of the appended claims.

[0138] Specific elements of any of the foregoing embodiments can be combined or substituted for elements in other embodiments. Furthermore, while advantages associated with certain embodiments of the disclosure have been described in the context of these embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the disclosure.

[0139] In some embodiments, the present technology may be defined in any of the following numbered paragraphs:1. A method comprising placing a composition comprising gellan gum between a target location and at least one adjacent non-target tissue or at least one adjacent non-target organ.2. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises at least one of: alginate; chitosan; a polyacrylic acid; a polyethylene glycol; a polyethylene oxide; a coblock polymer (e.g., poly(lactic-co-glycolic acid); and a poloxamer.3. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises neat (unmodified) gellan gum.4. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises at least one of modified gellan gum and cross-linked gellan gum.5. The method of paragraph 4, wherein the at least one of modified gellan gum and cross-linked gellan gum comprises high acyl gellan gum.6. The method of any one of paragraphs 4-5, wherein the at least one of modified gellan gum and cross-linked gellan gum comprises low acyl gellan gum.7. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises from 0.01-20 wt% gellan gum.8. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises from 0.05-10 wt% gellan gum.9. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises from 0.1-3 wt% gellan gum.10. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises more than 0.1 wt% gellan gum.35SUBSTITUTE SHEET (RULE 26)The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises less than 3 wt% gellan gum. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises 1.4-1.6 wt% gellan gum. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises 1.5 wt% gellan gum. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises at least one cross-linking ion. The method of paragraph 14, wherein the at least one cross-linking ion comprises one or more of Mg2+, Ca2+, Na+, and K+. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises at least one of: at least one Mg2+salt, at least one Ca2+salt, at least one Na+salt, and at least one K+salt. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises at least one of:MgCk NaCl, KC1, phosphate buffered saline (PBS), CaCL; DMEM; and EMEM. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a concentration of 0.1 mmol / L to 3.0 mol / L. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a concentration of 0.25 to 2.0 mmol / L. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises Ca2+at a concentration of 1.25 to 1.75 mmol / L. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises Mg2+at a concentration of 0.25 to 0.75 mmol / L. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum is at a temperature of no more than 40 °C. The method of any one of the preceding paragraphs, wherein the target is a tumor, abscess, scar tissue, nerve tissue, or tissue in need of surgical resection. The method of any one of the preceding paragraphs, wherein the target is a tumor. The method of any one of the preceding paragraphs, wherein the target is adjacent to, part of, or in contact with the kidney, liver, prostate, bone, breast, heart, bowel, colon, pancreas, diaphragm, or gastrointestinal system. The method of any one of the preceding paragraphs, further comprising administering a hyperthermal ablation treatment to the target.36SUBSTITUTE SHEET (RULE 26)The method of any one of the preceding paragraphs, wherein the target is insulated from heat, cold, and / or light as compared to the absence of the composition comprising gellan gum. The method of paragraph 27, whereby the composition comprising gellan gum reflects light. The method of paragraph 26, wherein the hyperthermal ablation treatment is a microwave ablation procedure, a computed tomography (CT) ablation procedure, or an ultrasound (US) ablation procedure. The method of paragraph 26, wherein the hyperthermal ablation treatment is a microwave ablation procedure. The method of any one of the preceding paragraphs, further comprising administering a radiation treatment to the target. The method of any one of the preceding paragraphs, further comprising administering an acid, an alkali, cryotherapy, a photodynamic therapy, a high intensity focused ultrasound, or electrocautery to the target. The method of any one of the preceding paragraphs, further comprising dissecting, excising or removing the target. The method of any one of the preceding paragraphs, further comprising placing an endoscopic device within the composition comprising a gellan gum. The method of any one of the preceding paragraphs, further comprising placing an implantable device, catheter, leads, stimulator, probe, or material within the composition comprising a gellan gum or on the target. The method of any one of the preceding paragraphs, further comprising administering a drug to the composition comprising a gellan gum or wherein the composition comprising a gellan gum further comprises a drug. The method of any one of the preceding paragraphs, further comprising administering a composition comprising one or more of:EDTA; glucose; glutathione; saline; and sodium bicarbonate to the subject. The method of paragraph 37, wherein the glucose is a 5% glucose solution. The method of paragraph 37, wherein the glucose is a 2-4% glucose solution. The method of paragraph 37, wherein the glucose is a 4-6% glucose solution. The method of paragraph 37, wherein the glucose is a 5% glucose solution. The method of any one of paragraphs 37-41, wherein the saline is a normal saline solution.37SUBSTITUTE SHEET (RULE 26)43. The method of any one of the preceding paragraphs, wherein the subject is not administered hydrodissection comprising or consisting of saline injection or dextrose solution injection.44. The method of any one of the preceding paragraphs, wherein the subject is not administered hydrodissection comprising or consisting of polyethylene glycol (PEG), collagen, pluronic 407, or hyaluronic acid.45. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum does not comprise polyethylene glycol (PEG), collagen, poloxamer 407, or hyaluronic acid.

[0140] In some embodiments, the present technology may be defined in any of the following numbered paragraphs:1. A method comprising placing a composition comprising gellan gum between a target location and at least one adjacent non-target tissue or at least one adjacent non-target organ.2. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises at least one of: alginate; chitosan; a polyacrylic acid; a polyethylene glycol; a polyethylene oxide; a coblock polymer (e.g., poly(lactic-co-glycolic acid); and a poloxamer.3. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises neat (unmodified) gellan gum.4. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises at least one of modified gellan gum and cross-linked gellan gum.5. The method of paragraph 4, wherein the at least one of modified gellan gum and cross-linked gellan gum comprises high acyl gellan gum.6. The method of any one of paragraphs 4-5, wherein the at least one of modified gellan gum and cross-linked gellan gum comprises low acyl gellan gum.7. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises from 0.01-20 wt% gellan gum.8. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises from 0.05-10 wt% gellan gum.9. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises from 0.1-3 wt% gellan gum.10. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises more than 0.1 wt% gellan gum.11. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises less than 3 wt% gellan gum.12. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises 1.4-1.6 wt% gellan gum.38SUBSTITUTE SHEET (RULE 26)The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises 1.5 wt% gellan gum. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises at least one cross-linking ion. The method of paragraph 14, wherein the at least one cross-linking ion comprises one or more of Mg2+, Ca2+, Na+, and K+. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises at least one of: at least one Mg2+salt, at least one Ca2+salt, at least one Na+salt, and at least one K+salt. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises at least one of:MgCh, NaCl, KC1, phosphate buffered saline (PBS), CaCh; DMEM; and EMEM. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a concentration of 0.1 mmol / L to 3.0 mol / L. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a concentration of 0.25 to 2.0 mmol / L. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises Ca2+at a concentration of 1.25 to 1.75 mmol / L. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises Mg2+at a concentration of 0.25 to 0.75 mmol / L. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum is at a temperature of no more than 40 °C. The method of any one of the preceding paragraphs, wherein the target is a tumor, abscess, scar tissue, nerve tissue, or tissue in need of surgical resection. The method of any one of the preceding paragraphs, wherein the target is a tumor. The method of any one of the preceding paragraphs, wherein the target is adjacent to, part of, or in contact with the kidney , liver, prostate, bone, breast, heart, bowel, colon, pancreas, diaphragm, or gastrointestinal system. The method of any one of the preceding paragraphs, further comprising administering a hyperthermal ablation treatment to the target. The method of any one of the preceding paragraphs, wherein the target is insulated from heat, cold, and / or light as compared to the absence of the composition comprising gellan gum. The method of paragraph 27, whereby the composition comprising gellan gum reflects light.39SUBSTITUTE SHEET (RULE 26)The method of paragraph 26, wherein the hyperthermal ablation treatment is a microwave ablation procedure, a computed tomography (CT) ablation procedure, or an ultrasound (US) ablation procedure. The method of paragraph 26, wherein the hyperthermal ablation treatment is a microwave ablation procedure. The method of any one of the preceding paragraphs, further comprising administering a radiation treatment to the target. The method of any one of the preceding paragraphs, further comprising administering an acid, an alkali, cryotherapy, a photodynamic therapy, a high intensity focused ultrasound, or electrocautery to the target. The method of any one of the preceding paragraphs, further comprising dissecting, excising or removing the target. The method of any one of the preceding paragraphs, further comprising placing an endoscopic device within the composition comprising a gellan gum. The method of any one of the preceding paragraphs, further comprising placing an implantable device, catheter, leads, stimulator, probe, or material within the composition comprising a gellan gum or on the target. The method of any one of the preceding paragraphs, further comprising administering a drug to the composition comprising a gellan gum or wherein the composition comprising a gellan gum further comprises a drug. The method of any one of the preceding paragraphs, further comprising administering a composition comprising one or more of:EDTA; glucose; glutathione; saline; and sodium bicarbonate to the subject. The method of paragraph 37, wherein the glucose is a 5% glucose solution. The method of paragraph 37, wherein the glucose is a 2-4% glucose solution. The method of paragraph 37, wherein the glucose is a 4-6% glucose solution. The method of paragraph 37, wherein the glucose is a 5% glucose solution. The method of any one of paragraphs 37-41, wherein the saline is a normal saline solution. The method of any one of the preceding paragraphs, wherein the subject is not administered hydrodissection comprising or consisting of saline injection or dextrose solution injection.40SUBSTITUTE SHEET (RULE 26)The method of any one of the preceding paragraphs, wherein the subject is not administered hydrodissection comprising or consisting of polyethylene glycol (PEG), collagen, pluronic 407, or hyaluronic acid. The method of any one of the preceding paragraphs, wherein the composition comprising gellan gum does not comprise polyethylene glycol (PEG), collagen, poloxamer 407, or hyaluronic acid. A composition comprising a gellan gum for use in a method of placing the composition between a therapeutic ablation target location situated within the body of a patient and at least one adjacent non-target tissue or at least one adjacent non-target organ. A composition comprising a gellan gum for use as a tissue shielding agent. The composition of paragraph 47, wherein the tissue shielding agent is introduced between a therapeutic ablation target location situated within the body of a patient and at least one adjacent non-target tissue or at least one adjacent non-target organ. A composition comprising a gellan gum for use in tissue displacement and / or hydrodissection. The composition of paragraph 49, wherein the composition is introduced between a therapeutic ablation target location situated within the body of a patient and at least one adjacent non-target tissue or at least one adjacent non-target organ. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises at least one of: alginate; chitosan; a polyacrylic acid; a polyethylene glycol; a polyethylene oxide; a coblock polymer (e.g., poly(lactic-co-glycolic acid); and a poloxamer. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises neat (unmodified) gellan gum. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises at least one of modified gellan gum and cross-linked gellan gum. The composition of paragraph 53, wherein the at least one of modified gellan gum and crosslinked gellan gum comprises high acyl gellan gum. The composition of any one of paragraphs 53-54, wherein the at least one of modified gellan gum and cross-linked gellan gum comprises low acyl gellan gum. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises from 0.01-20 wt% gellan gum. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises from 0.05-10 wt% gellan gum.41SUBSTITUTE SHEET (RULE 26)The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises from 0.1-3 wt% gellan gum. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises more than 0.1 wt% gellan gum. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises less than 3 wt% gellan gum. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises 1.4-1.6 wt% gellan gum. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum comprises 1.5 wt% gellan gum. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises at least one cross-linking ion. The composition of paragraph 63, wherein the at least one cross-linking ion comprises one or more of Mg2+, Ca2+, Na+, and K ", The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises at least one of: at least one Mg2+salt, at least one Ca2+salt, at least one Na+salt, and at least one K+salt. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises at least one of:MgCL. NaCl, KC1, phosphate buffered saline (PBS), CaCL: DMEM; and EMEM. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a concentration of 0.1 mmol / L to 3.0 mol / L. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a concentration of 0.25 to 2.0 mmol / L. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises Ca2+at a concentration of 1.25 to 1.75 mmol / L. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum further comprises Mg2+at a concentration of 0.25 to 0.75 mmol / L. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum is at a temperature of no more than 40 °C. The composition of any one of the preceding paragraphs, wherein the target is a tumor, abscess, scar tissue, nerve tissue, or tissue in need of surgical resection. The composition of any one of the preceding paragraphs, wherein the target is a tumor.42SUBSTITUTE SHEET (RULE 26)The composition of any one of the preceding paragraphs, wherein the target is adjacent to, part of, or in contact with the kidney, liver, prostate, bone, breast, heart, bowel, colon, pancreas, diaphragm, or gastrointestinal system. The composition of any one of the preceding paragraphs, further comprising administering a hyperthermal ablation treatment to the target. The composition of any one of the preceding paragraphs, wherein the target is insulated from heat, cold, and / or light as compared to the absence of the composition comprising gellan gum. The composition of paragraph 76, whereby the composition comprising gellan gum reflects light. The composition of paragraph 75, wherein the hyperthermal ablation treatment is a microwave ablation procedure, a computed tomography (CT) ablation procedure, or an ultrasound (US) ablation procedure. The composition of paragraph 75, wherein the hyperthermal ablation treatment is a microwave ablation procedure. The composition of any one of the preceding paragraphs, further comprising administering a radiation treatment to the target. The composition of any one of the preceding paragraphs, further comprising administering an acid, an alkali, cryotherapy, a photodynamic therapy, a high intensity focused ultrasound, or electrocautery to the target. The composition of any one of the preceding paragraphs, further comprising dissecting, excising or removing the target. The composition of any one of the preceding paragraphs, further comprising placing an endoscopic device within the composition comprising a gellan gum. The composition of any one of the preceding paragraphs, further comprising placing an implantable device, catheter, leads, stimulator, probe, or material within the composition comprising a gellan gum or on the target. The composition of any one of the preceding paragraphs, further comprising administering a drug to the composition comprising a gellan gum or wherein the composition comprising a gellan gum further comprises a drug. The composition of any one of the preceding paragraphs, further comprising administering a composition comprising one or more of:EDTA; glucose; glutathione; saline; and sodium bicarbonate43SUBSTITUTE SHEET (RULE 26)to the subject.87. The composition of paragraph 86, wherein the glucose is a 5% glucose solution.88. The composition of paragraph 86, wherein the glucose is a 2-4% glucose solution.89. The composition of paragraph 86, wherein the glucose is a 4-6% glucose solution.90. The composition of paragraph 86, wherein the glucose is a 5% glucose solution.91. The composition of any one of paragraphs 86-90, wherein the saline is a normal saline solution.92. The composition of any one of the preceding paragraphs, wherein the subject is not administered hydrodissection comprising or consisting of saline injection or dextrose solution injection.93. The composition of any one of the preceding paragraphs, wherein the subject is not administered hydrodissection comprising or consisting of polyethylene glycol (PEG), collagen, pluronic 407, or hyaluronic acid.94. The composition of any one of the preceding paragraphs, wherein the composition comprising gellan gum does not comprise polyethylene glycol (PEG), collagen, poloxamer 407, or hyaluronic acid.

[0141] The technology described herein is further illustrated by the following examples which in no way should be construed as being further limiting.EXAMPLESExample 1 : Transient hydrodissection hydrogel permits targeted, close-range, and shapeable tissuesparing ablation

[0142] Percutaneous, image-guided treatments including hyperthermal tumor ablations are a mainstay in the palette of cancer treatment options. The risk of collateral damage to neighboring critical organs from tumor ablations often necessitates pre-procedural tissue displacement and protection, but Standard of Care (SoC) tissue displacement strategies including hydrodissection (injection of fluid) are hampered by a combination of lack of control in deploy ability and poor retention time, worsening patient outcomes and limiting the scope of thermal ablations. Described herein is a rheological framework for new hydrodissection media and a corresponding hydrogel platform that accomplished longer-lasting, lower volume, and more controllable hydrodissection. Gel properties were tuned to achieve both inter- and intra-tissue hydrodissection and ablation protection. In vivo, demonstrated herein is 24 times longer-lasting hydrodissection volume using 40% less injected volume of gel than saline, creating a stable thermal barrier throughout microwave ablation. Further demonstrated is hydrogel structure-function tuned across all phases of hydrodissection44SUBSTITUTE SHEET (RULE 26)implementation to advance the translation of gels and augment percutaneous, image-guided procedures expandable to a wider range of endoscopic and laparoscopic surgeries.

[0143] Introduction

[0144] Percutaneous thermal ablation guided by computed tomography (CT) or ultrasound (US) has become a mainstay for treating malignant lesions in various locations, providing a minimally invasive and early-stage intervention for solid tumors compared to external beam radiation and chemotherapies, especially for patients who are not candidates for surgical resection.1 4Microwave ablation (MW A) is an increasingly predominant thermal ablation method for its high power, rapid heat delivery, and lower susceptibility to heat-sink effect from nearby blood vessels.5Early clinical studies have shown MWA can treat larger lesions usually untreatable by radiofrequency ablation (diameter >3 cm,), requires shorter ablation times (decreasing duration of general anesthesia and enabling the treatment of multiple lesions in the same session) and results in less blood loss.6'' However, the anatomic location of critical non-target tissues adjacent to the target lesions present a contraindication for MWA, as thermally-induced cardiac tamponade, bowel, colon, pancreatic, diaphragmatic, and gastrointestinal injuries have resulted in severe morbidity and mortalityl4. of which reports of the incidence of such injuries are biased by the exclusion of critically located tumors. At least 6-9% of ablations are limited by the position of the tumor, and one study with strategically placed thermocouples to monitor temperatures of adjacent structures found ablating tumors in this fashion was similar in risk to tumors distant to critical structures.15 16

[0145] Tissue displacement is an essential pre-ablation step to separate nearby organs and critical structures from the ablation zone (Fig 1A), which has previously been accomplished using fluid hydrodissection (the injection of saline or 5% dextrose solution) to create artificial ascites, injected gas, and / or balloon inflation. Artificial ascites in patients undergoing fluid hydrodissection are ephemeral due to rapid dispersion of fluid away from the hydrodissection site, requiring the injection of large volumes of fluid (upwards of sometimes ~2L per patient) and accompanying risk of focal edema and patient volume overload.121317Furthermore, the effectiveness of these Standard of Care (SoC) strategies is restricted by the positioning of the cavity available for deployment and patient’s anatomy, where gravitational and compressional effects from surrounding anatomical regions can make the displacement procedure lengthy or in some cases unachievable.18 19Decreased preprocedural time can minimize the time for patients under anesthesia and increase the ability for surgeons to perform multiple ablations in one session.5,8

[0146] A published case study demonstrated negative patient outcomes resulting directly from insufficient SoC tissue displacement methods. The patient’s tumor location was located adjacent to the stomach and precluded direct MWA (Fig. IB- 1). The surgical team attempted fluidic hydrodissection using CT-contrast (Fig IB-2), but the stomach-tumor barrier was minimal and inoperable due to flow of injected fluid away from the site of injection into regions of lower pressure45SUBSTITUTE SHEET (RULE 26)in the peritoneal cavity. Injected air rose to the top of the abdominal space and could not be properly retained at the injection site (Fig IB-3). A balloon was eventually inflated in the desired placement (Fig IB-4), but with challenging and lengthy maneuvering. Even after tissue displacement at the desired location is achieved, unstable tissue displacement distance or residence time forces surgeons to conduct MWA with greater margins, risking non-ablated malignant regions that are a major factor in local tumor progression.18,20In total, the inadequacy of SoC tissue displacement strategies for the lesion’s position resulted in a four-times longer MWA preparation duration than average, leading to a brachial plexus stretch injury-a complication associated with long-lasting cases-and an excess of over $10,000 additional procedural costs. There is a clinically unmet need for an injectable, conformable, and shapeable physical barrier system that permits temporally stable planar separation for MWA.

[0147] Hydrogels offer distinct advantages as hydrodissection media with tunable properties to fulfill varying needs of each individual stage of hydrodissection (Fig 1C). Gels can especially address shape adaptability and retention currently unachievable with fluid hydrodissection or balloons (Fig ID).21-23Successful biomedical hydrogel demonstrations have risen from such gel features, such as submucosal gel cushions for esophageal endoscopic dissection and gastrointestinal endoscopic surgery.24,23To our knowledge, the only commercially available gel evaluated for long-term safety in humans is the SpaceOAR polyethylene glucose (PEG)-based hydrogel; however, approval has been granted only for protecting the anterior rectum during prostate radiotherapy.6Additionally, while the 3 month duration the hydrogel resides within the body is optimized for radiotherapy, the residence time is unideal for shorter-term MWA operations.26Few gels have been evaluated for use in thermal ablation protection beyond initial studies of benchtop analysis of Pluronic 407 (P407) and hyaluronic acid, injection of P407 in a porcine model, and clinical injection of a fibrillar collagen slurry.21,22,27,28

[0148] Described herein is the development and validation of a rationally designed hydrogel platform evaluated for properties demanded by each stage of hydrodissection, especially simultaneous shapeability, triggerable degradability, and MWA thermal ablation protection. Material properties were evaluated that permitted both hydrodissection between (inter-) and within (intra-) tissues, under the hypothesis that gels would form larger and longer-lasting hydrodissection volumes in comparison to SoC saline injection while requiring less total fluid volume. It was further hypothesized that the gels injected pre-MWA could create hydrodissection pockets that decrease collateral tissue heating. Through gel characterization, benchtop, and in vivo testing, the ability of the instant hydrogel platform as a hydrodissection media for targeted tissue displacement and ablation protection inter- and intra- tissue was evaluated. Understanding the needs for hydrodissection gels holds significant value for opening a new frontier of gel-assisted surgical techniques, including MWA and similar interventional radiology and surgical procedures with improved spatial specificity and patient outcomes.

[0149] RESULTS46SUBSTITUTE SHEET (RULE 26)

[0150] Approach and Design

[0151] A rheological framework was developed to rationally design hydrodissection gels according to hydrodissection throughput requirements (Fig 1C). To understand the comprehensive material needs, the timeline of hydrodissection was analyzed in 4 general phases: 1) injection, 2) hydrodissection immediately at the site of injection, 3) resistance to deformation, and 4) outwards flow behavior.

[0152] Shear-thinning properties can be optimized to achieve injectability (criteria 1) and hydrodissection directly at the site of injection (criteria 2). Viscous over elastic behavior (tan5 > 1) at high shear permits viscous flow for injection through syringes. Conversely, dominant elastic behavior (tan8< 1) at low shear rates once gels exit the high shear environment of needles can be harnessed for gels to counteract gravitational and compressive barriers that restrict liquid injection in desired areas, producing an immediate shape-holding effect to permit buildup of subsequent injected gel. Once injected, the gel can be described as a mass with a resistance to deformation (criteria 3), exerting forces upon the surrounding tissues that compress inwards (as a function of intraperitoneal pressure, which increases with additional injected volume of material, and gravitational forces of overlying tissues). Residence time within the hydrodissection cavity (criteria 4) is decreased by its outwards flow rate, Q, in the presence of pressure differences (Pi, pressure increased in the hydrodissection area and P2, pressure of the surrounding peritoneal cavity areas), presented in equation (1):O = P2-P1 (1)R where R (residence to laminar flow) = 8r| L / TI r4and can be seen to be directly related to q. the viscosity of the solution.

[0153] Analysis of SoC normal saline and 5% dextrose solutions according to the criteria yields the following: though the low viscosity and land > 1 of aqueous fluids facilitates injection well (phase 1), the maintenance of tan8> 1 at all shear rates means the injected fluid is always subject to more viscous than elastic effects, and hence prefers to flow even after injection; this was observed in the case study to cause hydrodissection at the site of injection (phase 2) to fail. The resistance to deformation (phase 3) is thus restricted to how well the fluids are enclosed within the space. Once any outlets are present for outwards flow (phase 4), artificial ascites residence time can be expected to have an inverse relation to the pressures generated by hydrodissection (directly related to hydrodissection distance and opposing force of displaced mass).

[0154] Gellan gum (GG) was found to meet the outlined rheological needs for an improved hydrodissection media. GG has gained increasing traction for use in wound dressings, tissue scaffolds, and cell cultures for its high biocompatibility (common commercial food additive, status as a Generally Recognized as Safe (GRAS) compound, and history of FDA approval in medical devices),47SUBSTITUTE SHEET (RULE 26)degradability, and availability.29-35Assembly of the neat polymer backbones permits its gelation, where random coils are dispersed in heated aqueous solution and organize in entangled double helices upon cooling to form the gel state (Fig 2A).36The non-covalent nature of chain organization especially motivates GG Theologically for injection, with chain dissociation enabling the passage through needles used in interventional radiology procedures.

[0155] GG was directly gelled in a range of concentrations (1, 1.5, and 2 wt%) for rheological characterization. Viscous behavior (tanO > 1) at high strain was confirmed for all GG concentrations, representing predominant flowing for injectability (Figs. 2B and 2C). Conversely, dominant elastic effects (tan J < 1) at low strain % for the range of concentrations were observed, desirable for retaining gel volume directly at the site of injection instead of maximum outwards flow. Such injectability and shape-holding post-injection was observed empirically (Fig 2D), with ejection of saline solution for comparison. At constant strain within the rheological linear regime (representing GG resistance to deformation post-injection), GG gels displayed elastic behavior across all tested frequencies, with tunable modulus from 10-1000 Pa, corresponding to force exertion per tissue-gel interface area (Fig 2D). Dominant elasticity of GG gels across all tested frequencies is desirable for sustaining tissue-displacement in the constantly moving environments of the body during operations.

[0156] Residence time was simulated in a controlled pressurized setup (Fig 2F). Saline solution or GG (constant volume) was injected into a closed syringe to displace a stopper by 1 cm. Application of constant pressure and the opening of an exit valve were simultaneously placed upon the syringe, after which the “residence time,” time required for complete evacuation of media, was measured (Fig 2G). Saline dissipated within 2 seconds upon the application of 1 psi pressure, while GG1% required at least 4 minutes to evacuate under the same pressure. GG1.5% produced negligible movement with 1 psi and required an increase to 3 psi pressure to generate noticeable gel movement out of the syringe, with an average of at least 8 minutes residence time. GG2% required a further increase to 5 psi pressure, with 10 minutes residence time. Increasing residence times corresponded to increasing GG viscosities at higher GG concentration (Fig 2H). All GG concentrations demonstrated shearthinning behavior of decreasing viscosity with increasing shear rate, with power law indices of 0.313, 0.0782, and 0.0327, respectively (on a scale of 0 to 1, with higher injectability at lower values). All GG concentrations also exhibit dynamic yield stresses, which in a hydrodissection context represent a necessary barrier stress needed to overcome for greatly increased flow of hydrodissection volume from the site of injection (66 Pa, 62 Pa, and 6.9 kPa for GG1%, 1.5%, and 2%, respectively).Simultaneously, yield stresses for all GG concentrations were still magnitudes lower than maximum pressures applied by clinicians (up to 131 kPa).37The summation of these properties forwarded GG1.5% as the optimal GG concentration for maximizing residence time but maintaining injectability and minimizing the amount of GG used (in consideration of minimizing the amount of injected material).48SUBSTITUTE SHEET (RULE 26)

[0157] GG hydrogel cytotoxicity was analyzed using the 3-(4,5-Dimethylthiazol-2-yl)- 2,5- diphenyltetrazolium bromide (MTT) assay. Viability of HEK293 cells was monitored in 0.001 g / mL, 0.01 g / mL, and 1 g / mL GG hydrogel to analyze GG effects in even extreme concentrations. The Ig / mL GG series which has 66 times higher concentration than that of the GG 1.5% gel used in vitro.

[0158] GG1.5% exhibited complete dissolution in 20mM ethylenediaminetetraacetic acid (EDTA) in 5% glucose solution within 24h, or in 30mM EDTA-water after 150 hours (Fig. 21). All tested concentrations of GG are optically clear in the visible range for enabling endoscopy or biopsy through the gel (Fig 2J).

[0159] While neat GG hydrogels displayed attractive properties for inter-tissue hydrodissection, it was discovered that ionic cross-linking and “induced granularization” could be harnessed to create a GG-based gel to meet distinct rheological properties required for tissue displacement intra-tissue (to reach hydrodissective lesion boundaries deep within tissues) as well. In situ granulation at the syringeneedle interface of higher-modulus GG gels could be harnessed to generate smaller gel particles to accommodate tighter intra-tissue cavities and create hydrodissection volumes (Figs 3A and 3B). Divalent cations (Mg2+and Ca2+) were chosen for ionic cross-linking due to high EDTA chelation affinity to maintain maximally triggerable degradation. Notably, MgCL and CaCL utilized in the concentrations used in peritoneal dialysis (PD) solutions for maximum clinical translability. PD-ion balanced GG gels were named “GG-PDx.”

[0160] An incision in porcine liver tissue was created to provide a simulated observation plane for intra-tissue flow and expansion behavior. Direct injection of saline was unviable for intra-tissue hydrodissection, as injected fluid flowed directly outwards, creating less than 1 mm distance (Fig 3C). In contrast, neat GG created 4 mm intra-tissue distance, but reached a maximum hydrodissection force before spilling outwards (Fig 3C) and was subsequently expelled as a cohesive gel unit during MWA upon expansion of heated tissue. GG-PDx that was granulated in situ during injection into the incision separated the tissue by 4.7mm, where gel particles of higher modulus were retained and sustained the hydrodissection volume during MWA (Fig 3C and 4E).

[0161] GG-PDx displayed a balance of suitable modulus and injectability, with higher modulus than GG1.5% (Fig 3D) from ionic cross-linking to sustain separation intra-tissue hydrodissection, but simultaneously lower viscosity and stress at all shear rates from 0 to 100 s'1(Fig 3E and 3F, respectively) facilitated by granulated particles. GG-PDx exhibited rapid triggerable degradation using 15mM EDTA in 5wt% glucose (Fig 3G). Triggerable in situ degradation was further demonstrated within liver tissue, in which decreasing hydrodissection distances corresponded to decreased measurable gel mass remaining (Fig 3H). These demonstrate the ability to tailor gel properties to achieve hydrodissection capabilities in anatomical sites with varying mechanical environments, even in the interior of tissue masses.49SUBSTITUTE SHEET (RULE 26)

[0162] Benchtop MWA tests were conducted to analyze gel hydrodissection thermal protection compared to saline. The behavior of MWA in a neat saline solution was tested to observe MWA heat transfer through fluid. In the absence of physical barriers, heated solution rapidly was seen to spread radially from the MWA probe site, both conductively and convectively (Fig 4A). This indicated a further motivation for innovating upon SoC saline hydrodissection for thermal ablations, as the artificial ascites are not only ephemeral, but also facilitate rapid dispersion of heated fluids.

[0163] To compare the inter-tissue saline and gel hydrodissection thermal protection, MWA was performed in porcine liver tissue with another neighboring tissue representing healthy tissue to spare from MWA. The space in between the two pieces of tissue was filled with either saline (Fig 4B, top) or GG1.5% (Fig 4B, bottom). When MWA was performed with saline filling the inter-tissue space, the saline adjacent to the ablated tissue rapidly heated and spread, producing a 7-24°C increase throughout the inter-tissue space. In contrast, GG1.5% injected to fill the space in between two pieces of porcine liver (Fig 3E, orange outline) displayed improved confined heat dispersion and maintained a near 0°C temperature increase at the interface of the non-ablated tissue 1 cm away and a maximum of 5°C increased at the hottest points in the gel nearest to the ablation zone (Fig 4D, orange). A 23°C increase from physiologically normal temperatures (37°C) causes instant coagulative necrosis, whereas a 13-23°C increase increases the scale of coagulative necrosis to minutes.38Heat dispersion was observed to be more contained near the ablation zone when using GG in place of saline.

[0164] The protective effects of intra-tissue gel hydrodissection were also shown. GG-PDx was injected within two incisions made within hepatic tissue, representing borders marking ablation margins (Fig 4E, top). Tissues situated originally at the incision location were displaced outwards from the ablation zone by 0.5 cm. Upon MWA ablation, the GG-PDx hydrodissection volumes acted as a sacrificial ablated material (Fig 4E, bottom). Tissue on the side of the GG-PDx barrier closest to the ablation zone (original tissue pre-hydrodissection) experienced a 12.5°C increase, whereas displaced tissue was maintained at a maximum 5.1 °C increase. Thus, GG-PDx was shown as a sacrificial heated material to displace and protect ablation zone-periphery tissue.

[0165] Gel hydrodissection was evaluated in vivo through percutaneous injection in anesthetized swine. Hydrodissection pockets (with all dimensions >1 cm) were created under ultrasound guidance in the left perihepatic space between hepatic segments II / III and the lesser curvature of the stomach using saline (Fig 5A, top) and GG (Fig 5A, bottom), comparatively. Due to almost-immediate onset of saline dispersion post-injection, the creation of an exaggerated minimum hydrodissection spacing of ~2 cm was implemented in efforts to lengthen the artificial ascites residence time, requiring a total volume of 50mL saline for each pocket (Fib 5B inset; n=3). For all hydrodissection conducted with saline, the artificial ascites dissipated below 1 cm (minimum allowable dimension for ablation) within 10 minutes. When injecting GG, hydrodissection pockets remained stable over 4 hours post-injection50SUBSTITUTE SHEET (RULE 26)(Fig 5A, bottom and Fig 5B, orange; n=4) using only 40% of the volume used for saline (20 mL per injection).

[0166] In a separate anesthetized swine, MWA was performed post-hydrodissection (40 W, 3 min, max probe temp 80°C) in the left hepatic lobe. The ablation probe was inserted into segments 11 / 111 under ultrasound guidance. Temperature probes were inserted in tissue into hepatic parenchyma adjacent to the ablation probe as well as adjacent to the lesser curvature of the stomach on the far side of the GG hydrodissection pocket (located 2.7cm from the ablation probe) (Fig 5C). While the ablation zone was heated to 80°C over the course of the 3-minute ablation, the stomach tissue at the exterior of the GG hydrodissection pocket remained at 37°C (Fig 5D). The hydrodissection pocket remained stable after the ablation on CT imaging (Fig 5E). After euthanasia, surgical dissection of the region revealed intact gel contained at the site of injection as expected. Histological analysis showed intended coagulative necrosis in liver tissue (Fig 5F) as well as expected collateral bleeding in the peritoneum neighboring the ablation zone that was unprotected by GG (Fig 5G). Gastric tissue at the lesser curvature hydrodissected by GG remained without abnormalities and thermal injury (Fig 5H), nearly identical to gastric tissue at the greater curvature far away from the ablation zone (Fig 51).

[0167] DISCUSSION

[0168] Described herein is a rheological framework for gel hydrodissection that permits rational characterization of hydrogel material properties and optimization for improved MWA-protecting tissue displacement. A controlled pressurized setup permitted real-time quantification of hydrodissection media residence time, with observable increases in minimum pressure required to meaningfully displace the media. Such a setup can be further adapted to test a further range of hydrodissective media and molded to simulate anatomical cavity geometries. Based on the rational analysis of hydrodissective phases, GG was identified as a multifunctional hydrodissection gel. The dual gelling mechanisms of GG (helical organization and ionic cross-linking) were harnessed as separate handles to accordingly tune gel properties for tissue displacement both intra- and inter-tissue. When ionically cross-linking GG, desired mechanical properties were achieved using ion concentrations matched to those used in SoC peritoneal dialysis for maximum clinical translability. In vivo, shape-holding and flow resistance properties of GG permitted the use of 40% less volume than saline. Improved targeting and control diminishes the need for surgeons to overcompensate injection volumes and rush operations before rapid fluid dispersion occurs. As demonstrated herein, GG provided a 24 times longer-lasting MWA protection barrier compared to those of saline artificial ascites, enabling surgeons larger time and ablation margins for accurately positioning and safely performing MWA. From the preparation side, thermoreversible and one-pot gelation makes GG attractive for scalability (facile and bubble-free syringe loading) and on-demand deployability, avoiding in situ cross-linking of multiple precursor solutions or the use of dual-lumen catheters that risk clogging.51SUBSTITUTE SHEET (RULE 26)

[0169] In this study, a particular emphasis was placed on triggerable and non-enzymatic biodegradability to maximize biocompatibility and minimize gel residence time. The EDTA concentrations in degradation solutions were maintained at ~20 mM; while these are already in clinical use to treat lead poisoning, a wider tolerability window can be expected for the intraperitoneal injection used herein rather than intravenous injection used for lead poisoning.39-40The fast gel degradation in EDTA / 5% glucose also highlights biocompatibility and clinical translation by matching concentrations to SoC 5% glucose solutions routinely used clinically for fluid hydrodissection. Such accelerated degradation following intended use is theorized to limit infection and adhesion formation.

[0170] The gel-facilitated tissue displacement described herein can be applied to tumorous tissue and other anatomical targets.

[0171] The compositions and methods described herein can include integration of drugs, antibiotics, antitumoral agents, and additional stimuli-responsive properties that may augment patient outcomes achievable by gel hydrodissection. The compositions and methods described herein can be applied to endoscopic, laparoscopic and interventional radiology procedures previously barred by limited surgical access and lack of Theologically tuned materials, including tumor ablations and other applications of hydrodissection, reducing future morbidity and mortality for patients.

[0172] METHODS

[0173] Materials. Gellan Gum (Alfa Aesar) was used as purchased. MgCE’bl-LO (Sigma- Aldrich) and CaCh*2HiO (Sigma Aldrich) were used as ionic cross-linkers. EDTA (Sigma -Aldrich), sodium chloride (BioXtra, >99.5%, Sigma-Aldrich), and glucose (Sigma-Aldrich) were used as purchased in degradation solutions.

[0174] Gel preparation. Neat gellan gum was dissolved in Milli-Q water at 80°C at desired concentrations, transferred to syringes, and cooled into the gel phase to produce readily-injectable GG hydrogels. For GG-PDx gels, desired amounts of MgCTAjfFO and CaCFGFEO were dissolved and added dropwise to 80°C dissolved GG solutions, transferred to a syringe, and cooled into the gel phase. EDT

[0175] GG characterization. Rheological characterization (amplitude, frequency, and flow tests) was conducted using a HR20 Discovery Hybrid Rheometer (TA Instruments) with 20 mm parallel plate geometry at a constant temperature of 25°C. Frequency sweeps were conducted at a strain of 1% and 1 mm gap. Consistency (K) and shear-thinning (n) indices were calculated from flow tests. Samples were loaded by injecting gels through a 20G needle onto the parallel plate base with constant rotation.

[0176] Degradation was tested by submerging gel disks of constant dimensions in concentrations of EDTA in 0.9% normal saline solution or 5% glucose. Disks were tapped dry until no visible liquid remained on tapping napkins and weighed to determine the % of gel remaining.52SUBSTITUTE SHEET (RULE 26)

[0177] Differential Scanning Calorimetry (DSC) was performed on a TA Instruments Discovery DSC 250 (heating rate of 5°C).

[0178] Cytocompatibiltiy was analyzed using a MTT Assay. HEK293 cells were cultured in the presence of 1 g / mL, .01 g / mL, and .001 g / mL of GG 1.5% hydrogel with Dulbecco’s Modified Eagle Medium (Thermo), 10% fetal bovine serum (FBS), and 1% Pen-Strep (Thermo). 3 samples were conducted of each GG concentration and cell viability was measured at 24, 72, and 168 hours.

[0179] Controlled pressure setup. Dissipation time was measured in a pressure-controlled syringe stopper displacement setup (Fig. 6). A constant volume of media was injected into a vessel with a moveable stopper to displace the stopper by 1 cm. A constant pressure was applied simultaneously to opening a 3-way valve to allow outwards media flow. Dissipation time was measured as the time required to completely remove all media from the main vessel.

[0180] Ex vivo ablation performance. MWA was performed using an AMIGA GEN v.3.0 solid State Microwave Generator (2.45 GHz, 40W, 60°C maximum temperature). Thermometers and a FLIR SC5000 IR cooled camera were used for thermal measurements. MWA was performed in porcine liver.

[0181] In vivo testing. Male and female pigs (30kg) were used for all in vivo studies. Animals were premedicated using slow-release buprenorphine and meloxicam. During procedures, animals were anesthetized using 1.5-3% isoflurane in oxygen.

[0182] Tissue Harvest. Following euthanasia, tissue samples were carefully harvested from animals in the control and experimental groups. Tissue samples were fixed in 4% paraformaldehyde for 24 hours. They were then washed in phosphate buffered saline three times for 15 minutes each and stored in 70% ethanol. They were then paraffin processed, embedded, and then sectioned. Tissues were stained with 1) hematoxylin and eosin to assess morphology and surveil for adverse side effects related to the intervention.

[0183] REFERENCES1. Brock, K. K., Chen, S. R., Sheth, R. A. & Siewerdsen, J. H. Imaging in Interventional Radiology: 2043 and Beyond. Radiology 308, e230146 (2023).2. Ahmed, M., Brace, C. L., Lee, F. T. & Goldberg, S. N. Principles of and Advances in Percutaneous Ablation. Radiology 258, 351-369 (2011).3. Vetterlein, M. W. et al. Small renal masses in the elderly: Contemporary treatment approaches and comparative oncological outcomes of nonsurgical and surgical strategies. Investig. Clin. Urol. 57, 231 (2016).4. Low, G., Huang, G., Fu, W., Moloo, Z. & Girgis, S. Review of renal cell carcinoma and its common subtypes in radiology. World J. Radiol. 8, 484-500 (2016).5. Lubner, M. G., Brace, C. L., Hinshaw, J. L. & Lee, F. T. Microwave Tumor Ablation: Mechanism of Action, Clinical Results, and Devices. J. Vase. Interv. Radiol. 21, S192-S203 (2010).53SUBSTITUTE SHEET (RULE 26)6. Strickland, A. D. et al. Experimental study of large-volume microwave ablation in the liver. Br. J. Surg. 89, 1003-1007 (2002).7. Brace, C. L. et al. Microwave Ablation with Multiple Simultaneously Powered Small-gauge Triaxial Antennas: Results from an in Vivo Swine Liver Model. Radiology 244, 151-156 (2007).8. Boutros, C., Somasundar, P., Garrean, S., Saied, A. & Espat, N. J. Microwave coagulation therapy for hepatic tumors: Review of the literature and critical analysis. Surg. Oncol. 19, e22-e32 (2010).9. Shibata, T., Niinobu, T., Ogata, N. & Takami, M. Microwave coagulation therapy for multiple hepatic metastases from colorectal carcinoma. Cancer 89, 276-284 (2000).10. Laeseke, P. F. et al. Unintended Thermal Injuries from Radiofrequency Ablation: Protection with 5% Dextrose in Water. Am. J. Roentgenol. 186, S249-S254 (2006).11. Campbell, C., Lubner, M. G., Hinshaw, J. L., Del Rio, A. M. & Brace, C. L. Contrast Media- Doped Hydrodissection During Thermal Ablation: Optimizing Contrast Media Concentration for Improved Visibility on CT Images. Am. J. Roentgenol. 199, 677-682 (2012).12. Chung, M.-W. et al. Cardiac tamponade after radiofrequency ablation for hepatocellular carcinoma: Case report and literature review . Medicine (Baltimore) 97. el3532 (2018).13. Saito, T. et al. Fatal Diaphragmatic Hernia following Radiofrequency Ablation for Hepatocellular Carcinoma: A Case Report and Literature Review. Case Rep. Oncol. 8, 238-245 (2015).14. Koda, M., Ueki, M., Maeda, N. & Murawaki, Y. Diaphragmatic Perforation and Hernia After Hepatic Radiofrequency Ablation. Am. J. Roentgenol. 180, 1561-1562 (2003).15. Liang, P., Wang, Y ., Yu, X. & Dong, B. Malignant Liver Tumors: Treatment with Percutaneous Microwave Ablation — Complications among Cohort of 1136 Patients. Radiology 251, 933-940 (2009).16. McWilliams, J. P. et al. Percutaneous Ablation of Hepatocellular Carcinoma: Current Status. J. Case. Interv. Radiol. 21, S204-S213 (2010).17. Silverman, E. R., Lai, Y. H., Osborn, I. P. & Yudkowitz, F. S. Percutaneous radiofrequency ablation of hepatocellular lesions in segment II of the liver: a risk factor for cardiac tamponade. J. Clin. Anesth. 25, 587-590 (2013).18. Garnon, J. et al. Adjunctive Thermoprotection During Percutaneous Thermal Ablation Procedures: Review of Cunent Techniques. Cardiovasc. Intervent. Radiol. 42, 344-357 (2019).19. Gillams, A. R. & Lees, W. R. CT Mapping of the Distribution of Saline During Radiofrequency Ablation with Perfusion Electrodes. Cardiovasc. Intervent. Radiol. 28, 476-480 (2005).54SUBSTITUTE SHEET (RULE 26)20. Kang, T. W. et al. Percutaneous Radiofrequency Ablation for the Hepatocellular Carcinoma Abutting the Diaphragm: Assessment of Safety and Therapeutic Efficacy. Korean J. Radiol. 10, 34- 42 (2009).21. Moreland, A. J. et al. Evaluation of a Thermoprotective Gel for Hydrodissection During Percutaneous Microwave Ablation: In Vivo Results. Cardiovasc. Intervent. Radiol. 38, 722-730 (2015).22. Hasegawa, T. et al. Hyaluronic Acid Gel Injection to Prevent Thermal Injury of Adjacent Gastrointestinal Tract during Percutaneous Liver Radiofrequency Ablation. Cardiovasc. Intervent. Radiol. 36, 1144-1146 (2013).23. Wintjens, A. G. W. E. et al. Development of a Supramolecular Hydrogel for Intraperitoneal Injections. Macromol. Biosci. 2300005 (2023) doi:10.1002 / mabi.202300005.24. Fan, J. A. et al. Fractal design concepts for stretchable electronics. Nat. Commun. 5, (2014).25. Tang, S., Xu, Y., Su, G., Bao, J. & Zhang, A. Photoelectric and flexible polystyrene- b - ethylene / butylene- b -styrene)-zinc porphyrin-graphene hybrid composite: synthesis, performance, and mechanism. RSCAdv. 8, 35429-35436 (2018).26. FDA. De Novo Classification Request for SpaceOAR Summary. (2014).27. Johnson, A. et al. Design and Validation of a Thermoreversible Material for Percutaneous Tissue Hydrodissection. J. Biomed. Mater. Res. B Appl. Biomater. 101, 1400-1409 (2013).28. Majdalany, B. S., Willatt, J., Chick, J. F. B., Srinivasa, R. N. & Saad, W. A. Fibrillar collagen injection for organ protection during thermal ablation of hepatic malignancies. Diagn. Interv. Radiol.23, 381-384 (2017).29. Lozano, R. et al. 3D printing of layered brain-like structures using peptide modified gellan gum substrates. Biomaterials 67, 264-273 (2015).30. Jelkmann, M., Leichner, C., Zaichik, S., Laffleur, F. & Bemkop-Schmirch, A. A gellan gum derivative as in-situ gelling cationic polymer for nasal drug delivery. Int. J. Biol. Macromol. 158, 1037-1046 (2020).31. Gong, Y. et al. An improved injectable polysaccharide hydrogel: modified gellan gum for long-term cartilage regeneration in vitro. J. Mater. Chem. 19, 1968 (2009).32. Gering, C. et al. Chemical modification strategies for viscosity -dependent processing of gellan gum. Carbohydr. Polym. 269, 118335 (2021).33. Coutinho, D. F. et al. Modified Gellan Gum hydrogels with tunable physical and mechanical properties. Biomaterials 31, 7494-7502 (2010).34. Bacelar, A. H., Silva-Correia, J., Oliveira, J. M. & Reis, R. L. Recent progress in gellan gum hydrogels provided by functionalization strategies. J. Mater. Chem. B 4, 6164-6174 (2016).35. Xu, Y. et al. Cytocompatible, Injectable, and Electroconductive Soft Adhesives with Hybrid Covalent / Noncovalent Dynamic Network. Adv. Sci. 6, 1802077 (2019).55SUBSTITUTE SHEET (RULE 26)36. Tavagnacco, L. el al. Molecular origin of the two-step mechanism of gellan aggregation. Sci. Adv. 9, eadg4392 (2023).37. Hayward, W. et al. Pressure generated by syringes: implications for hydrodissection and injection of dense connective tissue lesions. Scand. J. Rheumatol. 40, 379-382 (2011).38. Wood, B. J., Ramkaransingh, J. R., Fojo, T., Walther, M. M. & Libutti, S. K. Percutaneous tumor ablation with radiofrequency. Cancer 94, 443 451 (2002).39. Zhu, H., Bao, B. & Zheng, X. Is NS-EDTA Effective in Clearing Bacteria From Infected Wounds in a Rat Model? Clin. Orthop. 476, 1083-1090 (2018).40. George, T. & Brady, M. F. Ethylenediaminetetraacetic Acid (EDTA). in StatPearls (StatPearls Publishing, 2023).Example 2

[0184] GG1.5% retention over 42 days and a representative histology afterwards.

[0185] The long-term behavior and retention of GG (1.5 wt / v%) was tested by injecting 0.5 mL of GG subcutaneously on the backs of C57BL / 6 mice (n=10). Ultrasound imaging was performed to measure the fraction of gel volume remaining (with mice under isoflurane anesthesia, 1.5-2% induction, 0.5-1. % maintenance) (Fig. 8A). No significant change in the gel volume was observed over 42 days (paired t test, p = 0.2182). Histological analysis for tissue post-explant showed minimal fibrotic encapsulation of 200-500 urn, indicating minimal foreign body reaction and suggesting longterm biocompatibility (Fig. 8B). These results indicate robust chronic viability of the gel platform in subcutaneous tissues.

[0186] Testing was also conducted in swine without adverse reactions. Injections in swine were demonstrated to help conduct electrical pulses to the celiac plexus.56SUBSTITUTE SHEET (RULE 26)

Claims

What is claimed herein is:

1. A method comprising placing a composition comprising gellan gum between a target location and at least one adjacent non-target tissue or at least one adjacent non-target organ.

2. The method of any one of the preceding claims, wherein the composition comprising gellan gum further comprises at least one of: alginate; chitosan; a polyacrylic acid; a polyethylene glycol; a polyethylene oxide; a coblock polymer (e.g., poly(lactic-co-glycolic acid); and a poloxamer.

3. The method of any one of the preceding claims, wherein the composition comprising gellan gum comprises neat (unmodified) gellan gum.

4. The method of any one of the preceding claims, wherein the composition comprising gellan gum comprises at least one of modified gellan gum and cross-linked gellan gum.

5. The method of claim 4, wherein the at least one of modified gellan gum and cross-linked gellan gum comprises high acyl gellan gum.

6. The method of any one of claims 4-5, wherein the at least one of modified gellan gum and cross-linked gellan gum comprises low acyl gellan gum.

7. The method of any one of the preceding claims, wherein the composition comprising gellan gum comprises from 0.01-20 wt% gellan gum.

8. The method of any one of the preceding claims, wherein the composition comprising gellan gum comprises from 0.05-10 wt% gellan gum.

9. The method of any one of the preceding claims, wherein the composition comprising gellan gum comprises from 0.1-3 wt% gellan gum.

10. The method of any one of the preceding claims, wherein the composition comprising gellan gum comprises more than 0.1 wt% gellan gum.

11. The method of any one of the preceding claims, wherein the composition comprising gellan gum comprises less than 3 wt% gellan gum.

12. The method of any one of the preceding claims, wherein the composition comprising gellan gum comprises 1.4-1.6 wt% gellan gum.

13. The method of any one of the preceding claims, wherein the composition comprising gellan gum comprises 1.5 wt% gellan gum.

14. The method of any one of the preceding claims, wherein the composition comprising gellan gum further comprises at least one cross-linking ion.

15. The method of claim 14, wherein the at least one cross-linking ion comprises one or more of Mg2+, Ca2+, Na+, and K+.

16. The method of any one of the preceding claims, wherein the composition comprising gellan gum further comprises at least one of: at least one Mg2+salt, at least one Ca2+salt, at least one Na+salt, and at least one K+salt.

17. The method of any one of the preceding claims, wherein the composition comprising gellan gum further comprises at least one of:MgC’T. NaCl, KC1, phosphate buffered saline (PBS), CaCT: DMEM; and EMEM.

18. The method of any one of the preceding claims, wherein the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a concentration of 0.1 mmol / L to 3.0 mol / L.

19. The method of any one of the preceding claims, wherein the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a concentration of 0.25 to 2.0 mmol / L.

20. The method of any one of the preceding claims, wherein the composition comprising gellan gum further comprises Ca2+at a concentration of 1.25 to 1.75 mmol / L.

21. The method of any one of the preceding claims, wherein the composition comprising gellan gum further comprises Mg2+at a concentration of 0.25 to 0.75 mmol / L.

22. The method of any one of the preceding claims, wherein the composition comprising gellan gum is at a temperature of no more than 40 °C.

23. The method of any one of the preceding claims, wherein the target is a tumor, abscess, scar tissue, nerve tissue, or tissue in need of surgical resection.

24. The method of any one of the preceding claims, wherein the target is a tumor.

25. The method of any one of the preceding claims, wherein the target is adjacent to, part of, or in contact with the kidney, liver, prostate, bone, breast, heart, bowel, colon, pancreas, diaphragm, or gastrointestinal system.

26. The method of any one of the preceding claims, further comprising administering a hyperthermal ablation treatment to the target.

27. The method of any one of the preceding claims, wherein the target is insulated from heat, cold, and / or light as compared to the absence of the composition comprising gellan gum.

28. The method of claim 27, whereby the composition comprising gellan gum reflects light.

29. The method of claim 26, wherein the hyperthermal ablation treatment is a microwave ablation procedure, a computed tomography (CT) ablation procedure, or an ultrasound (US) ablation procedure.

30. The method of claim 26, wherein the hyperthermal ablation treatment is a microwave ablation procedure.

31. The method of any one of the preceding claims, further comprising administering a radiation treatment to the target.

32. The method of any one of the preceding claims, further comprising administering an acid, an alkali, cryotherapy, a photodynamic therapy, a high intensity focused ultrasound, or electrocautery to the target.

33. The method of any one of the preceding claims, further comprising dissecting, excising or removing the target.

34. The method of any one of the preceding claims, further comprising placing an endoscopic device within the composition comprising a gellan gum.

35. The method of any one of the preceding claims, further comprising placing an implantable device, catheter, leads, stimulator, probe, or material within the composition comprising a gellan gum or on the target.

36. The method of any one of the preceding claims, further comprising administering a drug to the composition comprising a gellan gum or wherein the composition comprising a gellan gum further comprises a drug.

37. The method of any one of the preceding claims, further comprising administering a composition comprising one or more of:EDTA; glucose; glutathione; saline; and sodium bicarbonate to the subject.

38. The method of claim 37, wherein the glucose is a 5% glucose solution.

39. The method of claim 37, wherein the glucose is a 2-4% glucose solution.

40. The method of claim 37, wherein the glucose is a 4-6% glucose solution.

41. The method of claim 37, wherein the glucose is a 5% glucose solution.

42. The method of any one of claims 37-41, wherein the saline is a normal saline solution.

43. The method of any one of the preceding claims, wherein the subject is not administered hydrodissection comprising or consisting of saline injection or dextrose solution injection.

44. The method of any one of the preceding claims, wherein the subject is not administered hydrodissection comprising or consisting of polyethylene glycol (PEG), collagen, pluronic 407, or hyaluronic acid.

45. The method of any one of the preceding claims, wherein the composition comprising gellan gum does not comprise polyethylene glycol (PEG), collagen, poloxamer 407, or hyaluronic acid.

46. A composition comprising a gellan gum for use in a method of placing the composition between a therapeutic ablation target location situated within the body of a patient and at least one adjacent non-target tissue or at least one adjacent non-target organ.

47. A composition comprising a gellan gum for use as a tissue shielding agent.

48. The composition of claim 47, wherein the tissue shielding agent is introduced between a therapeutic ablation target location situated within the body of a patient and at least one adjacent non-target tissue or at least one adjacent non-target organ.

49. A composition comprising a gellan gum for use in tissue displacement and / or hydrodissection.

50. The composition of claim 49, wherein the composition is introduced between a therapeutic ablation target location situated within the body of a patient and at least one adjacent non- target tissue or at least one adjacent non-target organ.

51. The composition of any one of the preceding claims, wherein the composition comprising gellan gum further comprises at least one of: alginate; chitosan; a polyacrylic acid; a polyethylene glycol; a polyethylene oxide; a coblock polymer (e.g., poly(lactic-co-glycolic acid); and a poloxamer.

52. The composition of any one of the preceding claims, wherein the composition comprising gellan gum comprises neat (unmodified) gellan gum.

53. The composition of any one of the preceding claims, wherein the composition comprising gellan gum comprises at least one of modified gellan gum and cross-linked gellan gum.

54. The composition of claim 53, wherein the at least one of modified gellan gum and crosslinked gellan gum comprises high acyl gellan gum.

55. The composition of any one of claims 53-54, wherein the at least one of modified gellan gum and cross-linked gellan gum comprises low acyl gellan gum.

56. The composition of any one of the preceding claims, wherein the composition comprising gellan gum comprises from 0.01-20 wt% gellan gum.

57. The composition of any one of the preceding claims, wherein the composition comprising gellan gum comprises from 0.05-10 wt% gellan gum.

58. The composition of any one of the preceding claims, wherein the composition comprising gellan gum comprises from 0.1-3 wt% gellan gum.

59. The composition of any one of the preceding claims, wherein the composition comprising gellan gum comprises more than 0.1 wt% gellan gum.

60. The composition of any one of the preceding claims, wherein the composition comprising gellan gum comprises less than 3 wt% gellan gum.

61. The composition of any one of the preceding claims, wherein the composition comprising gellan gum comprises 1.4- 1.6 wt% gellan gum.

62. The composition of any one of the preceding claims, wherein the composition comprising gellan gum comprises 1.5 wt% gellan gum.

63. The composition of any one of the preceding claims, wherein the composition comprising gellan gum further comprises at least one cross-linking ion.

64. The composition of claim 63, wherein the at least one cross-linking ion comprises one or more of Mg2+, Ca2+, Na+, and K+.

65. The composition of any one of the preceding claims, wherein the composition comprising gellan gum further comprises at least one of: at least one Mg2+salt, at least one Ca2+salt, at least one Na+salt, and at least one K+salt.

66. The composition of any one of the preceding claims, wherein the composition comprising gellan gum further comprises at least one of:MgC’T. NaCl, KC1, phosphate buffered saline (PBS), CaCT: DMEM; and EMEM.

67. The composition of any one of the preceding claims, wherein the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a concentration of 0.1 mmol / L to 3.0 mol / L.

68. The composition of any one of the preceding claims, wherein the composition comprising gellan gum further comprises Mg2+and / or Ca2+at a concentration of 0.25 to 2.0 mmol / L.

69. The composition of any one of the preceding claims, wherein the composition comprising gellan gum further comprises Ca2+at a concentration of 1.25 to 1.75 mmol / L.

70. The composition of any one of the preceding claims, wherein the composition comprising gellan gum further comprises Mg2+at a concentration of 0.25 to 0.75 mmol / L.

71. The composition of any one of the preceding claims, wherein the composition comprising gellan gum is at a temperature of no more than 40 °C.

72. The composition of any one of the preceding claims, wherein the target is a tumor, abscess, scar tissue, nerve tissue, or tissue in need of surgical resection.

73. The composition of any one of the preceding claims, wherein the target is a tumor.

74. The composition of any one of the preceding claims, wherein the target is adjacent to, part of, or in contact with the kidney, liver, prostate, bone, breast, heart, bowel, colon, pancreas, diaphragm, or gastrointestinal system.

75. The composition of any one of the preceding claims, further comprising administering a hyperthermal ablation treatment to the target.

76. The composition of any one of the preceding claims, wherein the target is insulated from heat, cold, and / or light as compared to the absence of the composition comprising gellan gum.

77. The composition of claim 76, whereby the composition comprising gellan gum reflects light.

78. The composition of claim 75, wherein the hyperthermal ablation treatment is a microwave ablation procedure, a computed tomography (CT) ablation procedure, or an ultrasound (US) ablation procedure.

79. The composition of claim 75, wherein the hyperthermal ablation treatment is a microwave ablation procedure.

80. The composition of any one of the preceding claims, further comprising administering a radiation treatment to the target.

81. The composition of any one of the preceding claims, further comprising administering an acid, an alkali, cryotherapy, a photodynamic therapy, a high intensity focused ultrasound, or electrocautery to the target.

82. The composition of any one of the preceding claims, further comprising dissecting, excising or removing the target.

83. The composition of any one of the preceding claims, further comprising placing an endoscopic device within the composition comprising a gellan gum.

84. The composition of any one of the preceding claims, further comprising placing an implantable device, catheter, leads, stimulator, probe, or material within the composition comprising a gellan gum or on the target.

85. The composition of any one of the preceding claims, further comprising administering a drug to the composition comprising a gellan gum or wherein the composition comprising a gellan gum further comprises a drug.

86. The composition of any one of the preceding claims, further comprising administering a composition comprising one or more of:EDTA; glucose; glutathione; saline; and sodium bicarbonate to the subject.

87. The composition of claim 86, wherein the glucose is a 5% glucose solution.

88. The composition of claim 86, wherein the glucose is a 2-4% glucose solution.

89. The composition of claim 86, wherein the glucose is a 4-6% glucose solution.

90. The composition of claim 86, wherein the glucose is a 5% glucose solution.

91. The composition of any one of claims 86-90, wherein the saline is a normal saline solution.

92. The composition of any one of the preceding claims, wherein the subject is not administered hydrodissection comprising or consisting of saline injection or dextrose solution injection.

93. The composition of any one of the preceding claims, wherein the subject is not administered hydrodissection comprising or consisting of polyethylene glycol (PEG), collagen, pluronic 407, or hyaluronic acid.

94. The composition of any one of the preceding claims, wherein the composition comprising gellan gum does not comprise polyethylene glycol (PEG), collagen, poloxamer 407, or hyaluronic acid.

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