Implantable medical devices

Abstract

An implantable medical device comprising a polymer material that generates nitric oxide, wherein (i) A polymer material that generates nitric oxide comprises a polymer and (a) particles (wherein one or more individual particles each containing a nitrite and a proton source); or (b) aggregates of particles (wherein the aggregates each comprises one or more individual particles containing a nitrite, one or more individual particles containing a proton source, and optionally a binder, or the aggregates of particles each comprises one or more individual particles each containing a nitrite and a proton source, and optionally a binder); (ii) The polymer material that generates nitric oxide contains a polymer that is a proton source, and the polymer material that generates nitric oxide contains a nitrite dissolved in the polymer matrix that is a proton source; or (iii) A combination of (i) and (ii) above, Implantable medical device.

Description

[Technical Field]

[0001] The present invention relates to an implantable medical device comprising a polymer material that generates nitric oxide, wherein (i) A polymer material that generates nitric oxide comprises a polymer and (a) particles (wherein one or more individual particles each containing a nitrite and a proton source); or (b) aggregates of particles (wherein the aggregates each comprises one or more individual particles containing a nitrite, one or more individual particles containing a proton source, and optionally a binder, or the aggregates of particles each comprises one or more individual particles each containing a nitrite and a proton source, and optionally a binder); (ii) The polymer material that generates nitric oxide contains a polymer that is a proton source, and the polymer material that generates nitric oxide contains a nitrite dissolved in the polymer matrix that is a proton source; or (iii) A combination of (i) and (ii) above, Regarding implantable medical devices. [Background technology]

[0002] The medical applications of nitric oxide (NO) and its precursors have been widely studied. However, substantial problems remain regarding the efficient production of nitric oxide, other nitrogen oxides, and their precursors, and their delivery to organs and cells for therapeutic purposes. The widely employed system for nitric oxide production relies on the acidification of nitrites using a proton source such as an acid, first producing nitrite (HNO2), which then readily decomposes into nitric oxide and nitrates simultaneously with hydrogen ions and water. This decomposition is described by the following equilibrium equation (1):

number

[0003] The acid and nitrite are typically supplied in predetermined amounts as separate components. These separate components are stored separately until use to minimize the reaction until the required time. Thus, these two reactants are supplied in a two-component system comprising a component containing the nitrite and a separate component containing the acid. In this way, the two separate components in the two separate components can be combined or mixed at the required time, preventing the release of nitric oxide before it is needed.

[0004] Nitric oxide (NO) is associated with a key regulator of tissue repair and regeneration in multiple tissues, including but not limited to skin, tendons, and bone. In experimental and clinical studies, exogenous delivery of NO has been shown to restore healing in damaged dermal wounds. Topical delivery of the NO prodrug glyceryl trinitrate (GTN) has been shown in several clinical studies to rapidly and sustainably alleviate symptoms resulting from rotator cuff tears and other tendon injuries. However, the clinical application of GTN for tendon injuries has been limited by systemic adverse side effects associated with transdermal delivery and NO production (particularly migraine-like headaches).

[0005] Implantable medical devices are known for a variety of clinical applications. Extensive use of synthetic polymers in medical devices such as sutures and scaffolds includes, but is not limited to, polylactic acid (PLA), polyglycolic acid (PGA), polycaprolactone (PCL), or composite materials thereof. Over the past 40 years, these materials have demonstrated excellent biocompatibility when used in a wide range of clinical applications. However, devices composed of these materials are primarily passive in the healing response, either by tying together damaged tissue or protecting the site from harmful mechanical damage, creating a stable environment in which the endogenous repair response can proceed. [Overview of the project]

[0006] To address the lack of bioactivity of synthetic polymers and the adverse effects of systemic exposure to NO prodrugs, the inventors have developed a manufacturable synthetic biopolymer composition that delivers bioactive amounts of NO directly to the site of tissue repair and regeneration. By incorporating a stable powder of an acidified nitrite reaction into a synthetic medical polymer, a scaffold (device) is generated that can be directly implanted at the site of tissue damage, providing a structural scaffold that supports tissue repair by releasing nitric oxide in amounts that support tissue repair and regeneration. In other words,

[0007] In its most common embodiment, the present invention provides an implantable medical device having a polymer material that generates nitric oxide, wherein the nitric oxide-generating polymer material comprises (i) a polymer and particles or aggregates of particles containing both a nitrite and a proton source, or (ii) a polymer of an acid source and a nitrite dissolved in a polymer matrix. Thus, the nitrite and the proton source maintain a close proximity (or close association) state to provide acidification of the nitrite when in contact in an aqueous environment, but do not react substantially until required, thus providing a single-component system. By including solid components of both the nitrite and the acid source, contamination with a water source (such as a solution or aqueous gel) can be avoided. Thus, exposure of the reactants to water is reduced before the reaction is required, and the reaction is minimized.

[0008] In a first embodiment, the present invention relates to an implantable medical device comprising a polymer material that generates nitric oxide, wherein (i) A polymer material that generates nitric oxide comprises a polymer and (a) particles (wherein one or more individual particles each containing a nitrite and a proton source); or (b) aggregates of particles (wherein the aggregates each comprises one or more individual particles containing a nitrite, one or more individual particles containing a proton source, and optionally a binder, and / or the aggregates of particles each comprises one or more individual particles each containing a nitrite and a proton source, and optionally a binder); (ii) The polymer material that generates nitric oxide contains a polymer that is a proton source, and the polymer material that generates nitric oxide contains a nitrite dissolved in the polymer matrix that is a proton source; or (iii) A combination of (i) and (ii) above, Regarding implantable medical devices.

[0009] The polymer material that generates nitric oxide may have a water content of 10% or less, 5% or less, 2% or less, or 1% or less before transplantation, or the polymer material that generates nitric oxide may not contain substantially any water. The polymer material that generates nitric oxide may be present on the outer surface of the implantable medical device. The polymer material that generates nitric oxide may form a scaffold for an implantable medical device, the polymer material that generates nitric oxide may form a coating on another component of the implantable medical device, or the polymer material that generates nitric oxide may form part of the fabric of the implantable medical device.

[0010] The polymer material that generates nitric oxide may be a fiber or a coating. An implantable medical device may be a single-component device. The polymer material that generates nitric oxide may include a) particles (wherein one or more individual particles each containing a nitrite and a proton source); or (b) aggregates of particles (wherein the aggregates each contains one or more individual particles containing a nitrite, one or more individual particles containing a proton source, and optionally a binder, and / or the aggregates of particles each contains one or more individual particles each containing a nitrite and a proton source, and optionally a binder).

[0011] One or more individual particles or aggregates of particles may be blended or coated with excipients that affect the rate at which water penetrates the particles, and / or excipients that affect the rate at which nitric oxide is formed from the particles. Excipients that affect the rate of penetration into water particles may be hydrophobic materials such as polyols or phospholipids, magnesium stearate or colloidal silica, and / or excipients that affect the rate of penetration into water particles may be materials that sequestrate nitric oxide or nitric oxide precursors, such as thiols, alcohols, amines or amides.

[0012] Particles containing both nitrite and a proton source may be formed by spray-drying a mixture containing a nitrite solution and a proton source solution. The polymer material that generates nitric oxide may include a proton source polymer. The proton source polymer may be an acidic polymer, a photoacid polymer, or an acid precursor polymer such as a hydrolyzable ester. One or more particles or aggregates of particles may be embedded or partially embedded within the polymer of the nitric oxide-producing polymer material. Alternatively, one or more particles or aggregates of particles may be attached to the surface of the polymer of the nitric oxide-producing polymer material.

[0013] The polymer material that generates nitric oxide may include a polymer of a proton source, and the polymer material that generates nitric oxide may include nitrite dissolved in a polymer matrix of a proton source. In these embodiments, the nitrite may be mixed essentially homogeneously with the polymer matrix of the proton source. The polymer material that generates nitric oxide may be formed from a non-aqueous solution of nitrite and a polymer of a proton source. The polymer of the polymer material that generates nitric oxide may be a biocompatible polymer. The polymer of the polymer material that generates nitric oxide may be an absorbent material. The proton source may include an acid, an acid precursor such as an ester, or a photoacid.

[0014] The implantable medical device may include one or more additional dry components adjacent to the polymer material that generates nitric oxide. The implantable medical device may include one or more additional components adjacent to the polymer material that generates nitric oxide: provided that the water content of any component adjacent to the polymer material that generates nitric oxide is 10% or less, 5% or less, 2% or less, or 1% or less based on the weight of the component adjacent to the polymer material that generates nitric oxide. The implantable medical device may include an antimicrobial agent. The implantable medical device may be a one-piece medical device.

[0015] In a second aspect, the present invention provides a packaged implantable medical device comprising the implantable medical device described herein within a low moisture permeability package. The low moisture permeability package may include one or more low moisture permeability materials (e.g., aluminum foil) in the walls of the package and / or may be sealed. The atmosphere of the package within the packaged implantable medical device has a low moisture content at the time of initial packaging and / or the package includes a pack insert that isolates moisture.

[0016] In a third aspect, the present invention provides a method for implanting an implantable medical device, comprising implanting an implantable medical device as described herein. The implantable medical device may be a single-component implantable medical device.

[0017] In a fourth aspect, the present invention provides particles or aggregates of particles for use in implanting an implantable medical device as described herein, wherein (a) one or more individual particles each contain a nitrite and a proton source; or (b) the aggregate comprises one or more individual particles containing a nitrite, one or more individual particles containing a proton source, and optionally a binder, and / or the aggregates of particles comprise one or more individual particles each containing a nitrite and a proton source, and optionally a binder. The implantable medical device may be a single-component implantable medical device.

[0018] Any or specific features of one aspect of the present invention described herein are equally applicable to other aspects of the present invention, insofar as the features are compatible with the aspect. In particular, any or specific features of an implantable medical device are equally applicable to a packaged implantable medical device, a method for implanting an implantable medical device, and particles or aggregates of particles used in an implantable medical device, insofar as the features are compatible with these components. [Brief explanation of the drawing]

[0019] The present invention will now be described in more detail. Examples and accompanying drawings are provided as illustrations of the present invention. [Figure 1] This image shows a scanning electron microscope image of a PCL fiber that does not contain particles that generate nitric oxide. [Figure 2] This image shows a scanning electron image of a PCL fiber loaded with 1% w / w of nitric oxide-generating particles. The particles appear as white dots within the fiber. [Figure 3]This image shows a scanning electron image of a PCL fiber loaded with nitric oxide-generating particles at 5% w / w. The particles appear as white dots within the fiber. [Figure 4] This image shows a scanning electron image of a PCL fiber loaded with 10% w / w of nitric oxide-generating particles. The particles appear as white dots within the fiber. [Figure 5] This image shows a scanning electron microscope image of a TPU fiber that does not contain particles that generate nitric oxide. [Figure 6] This image shows a scanning electron image of a TPU fiber loaded with 1% w / w of nitric oxide-generating particles. The particles appear as white dots within the fiber. [Figure 7] This image shows a scanning electron image of a TPU fiber loaded with nitric oxide-generating particles at 5% w / w. The particles appear as white dots within the fiber. [Figure 8] This image shows a scanning electron image of a TPU fiber loaded with 10% w / w of nitric oxide-generating particles. The particles appear as white dots within the fiber. [Figure 9] The fluorescence intensity vs. time of the NO sensor (DAF-FM) of the electrospun fiber in Example 8 is shown. [Figure 10] The deposition patterns of the powders from Examples 1A, 2, 3, and 4 on agarose using Hanks equilibrium salt solution and pH indicator (phenol red) are shown. [Figure 11] The cumulative NO production amounts for Examples 1A, 2, 3, and 4 are shown. [Figure 12] The germination strength of HUVEC spheroids treated in Examples 1B and 6A is shown, quantified using an image analysis system and measured by comparing the cumulative germination length (CSL) per spheroid with a reference control. [Figure 13] The morphology of VERO cells grown on a PLGA scaffold that releases NO 7 days after culturing is shown. A: No nitric oxide releasing powder; B: Powder releasing 1% (wt / wt) nitric oxide; C: Powder releasing 5% (wt / wt) nitric oxide; D: Powder releasing 10% (wt / wt) nitric oxide [Figure 14]Scanning electron microscope images of PLGA fibers containing sodium nitrite are shown. Figures 14A, 14B, and 14C show fibers from Examples 14A, 14B, and 14C, respectively. [Figure 15A] The pH of Examples 14A-D over time is shown. [Figure 15B] The fluorescence intensity profiles over time for Examples 14A-D are shown. [Modes for carrying out the invention]

[0020] Reactions between one or more nitrites and a proton source that produce nitric oxide, optionally other oxides of nitrogen and / or optionally their precursors are referred herein to as “NOx-producing reactions” or “NOx-generating reactions,” where “NOx” is used to refer collectively to the products of the acidification of nitrites, in particular nitric oxide, other oxides of nitrogen and / or their precursors, individually or in any combination. It will be understood that each component of the NOx produced may evaporate as a gas, migrate in solution within the reaction mixture, or migrate initially in solution and then evaporate as a gas, or any combination thereof.

[0021] The term "approximately" is used herein to mean that the numerical value is not strictly limited, and those skilled in the art will understand that the value may (as necessary) range above or below the exact value in accordance with the understanding of the value by those skilled in the art. The term "approximately" may mean a value within ±10% of the value. In this specification, particle size refers to volume-average diameter (VMD) unless otherwise specified.

[0022] As used herein, the terms “one-component,” “single-component,” and “two-component” refer to the number of pieces of an implantable medical device up to the point in time when it is required (e.g., implantation into a target). For example, a one-component implantable medical device is supplied as a single piece up to the point in time when it is required. A one-component implantable medical device is typically implanted into a target as a single piece. In contrast, a two-component implantable medical device is supplied as two pieces up to the point in time when it is required, and is typically combined into a single-component implantable medical device immediately before implantation into a target. It should also be noted that the one-component implantable medical devices described herein may be formed from a polymer material that generates nitric oxide and one or more other components.

[0023] Implantable medical devices As used herein, “implantable medical device” refers to a device that is implanted in a subject (e.g., a human or an animal). Implantable medical devices are typically manufactured to replace a missing biological structure, support a damaged biological structure, or reinforce an existing biological structure. Implantable medical devices are widely known in themselves.

[0024] Examples of implantable medical devices include, but are not limited to, sensory and nerve implants (such as intraocular lenses, keratoconus ring segments, cochlear implants, tympanotomy tubes, and nerve stimulators), artificial vascular implants (such as artificial hearts, artificial heart valves, implantable defibrillators, artificial cardiac pacemakers, and coronary stents), orthopedic implants (such as pins, rods, screws, plates, and combinations thereof used to fix fractured bones until they heal), electrical implants, contraceptive implants (such as copper and hormone-based intrauterine devices), cosmetic implants, and implants for other organs and systems (such as LINX, implantable gastric stimulators, diaphragmatic / cranial nerve stimulators, nerve stimulators, surgical meshes, artificial urethral sphincters, and penile implants).

[0025] The polymer material that generates nitric oxide may be replaced with materials that constitute known implantable medical devices. For example, the polymer material that generates nitric oxide may form, for example, a scaffold for a cardiovascular stent, or a coating for an electrical implant. Alternatively, the polymer material that generates nitric oxide may be included as any further material that constitutes a known implantable medical device. For example, the polymer material that generates nitric oxide may form a further coating on the surface of an artificial joint.

[0026] Polymer material that produces nitric oxide The implantable medical device of the present invention comprises a polymer material that generates nitric oxide for producing nitric oxide by acidifying a nitrite, wherein the nitric oxide generating material comprises a polymer, a nitrite component, and a proton source component. The arrangement of the nitrite in the polymer may be either as particles or aggregates of particles, wherein the particles or aggregates contain both the nitrite component and the proton source component. Alternatively, the nitrite may be dissolved in the polymer of the proton source.

[0027] Thus, the nitrite and the proton source may be placed in close proximity to ensure sufficient reaction when exposed to an aqueous environment. The nitrite and proton source are present in the polymer material of the implantable medical device. In this way, these components do not need to be combined (as part of a two-component system) during use. Typically, polymer materials are solid polymer materials. Typically, particles or aggregates of particles are solid particles. In this way, the water content can be kept to a minimum, thus reducing the generation of nitric oxide before use.

[0028] Typically, all components of the polymer material that produces nitric oxide are dry components. Thus, the reaction between the nitrite and the acid component is minimized before use. The water content of the polymer material that produces nitric oxide can be 10% or less, 5% or less, 2% or less, or 1% or less, based on the weight of the polymer material. Thus, the reaction between the nitrite and the proton source reactants is minimized until use. The water content may be measured by standard laboratory methods, such as weighing the sample, removing the moisture (e.g., by drying it in an oven at a temperature above 100°C), and then weighing the sample again.

[0029] The polymer material that generates nitric oxide may contain one or more fibers. The polymer material that generates nitric oxide may be a woven or nonwoven fiber material. The polymer material that generates nitric oxide may be a coating on a substrate. The polymer material that generates nitric oxide may form a scaffold for a medical device. The polymer in the polymer material that generates nitric oxide may be adsorbent. The polymer material may consist of woven or nonwoven fibers or a solid foam. The polymer material may consist of fibers of cotton, rayon, polyester (such as PLGA), and / or gelling fibers such as carboxymethylcellulose and its salts. Additionally, or by alternative means, the polymer material may be a solid foam of a hydrophilic material (e.g., silicone).

[0030] In certain embodiments, the polymer material that generates nitric oxide is on or forms the outer surface of the implantable medical device during use. Thus, the nitric oxide generating layer is exposed to the implantation site and directly supplies nitric oxide to that site. Alternatively, the implantable medical device may have one or more permeable layers or elements outside the polymer layer that generates nitric oxide. The implantable medical device may include one or more permeable layers adjacent to the polymer material that generates nitric oxide, and may be configured so that one or more permeable layers come into contact with the implantation site during use. One or more permeable layers may be made from any permeable material, typically any gas and / or liquid permeable material. Thus, nitric oxide can enter these layers, and / or liquids can pass through these layers to the polymer material that generates nitric oxide.

[0031] The polymer material that generates nitric oxide may further contain one or more active pharmaceutical ingredients (APIs). In this way, the polymer material that generates nitric oxide may be able to directly deliver one or more active pharmaceutical ingredients to the implantation site. The APIs are not particularly limited. Certain APIs may include one or more analgesics, one or more anti-inflammatory agents, one or more additional antimicrobial agents, and / or one or more anticoagulants. Acidification of nitrite components and proton source components typically exhibits antimicrobial activity. In some examples, implantable medical devices contain additional antimicrobial agents. Antimicrobial agents are known to the extent. In some examples, implantable medical devices contain AgNO2 as both an antimicrobial agent and a nitrite.

[0032] Polymer material that generates nitric oxide The polymer material that generates nitric oxide comprises at least one polymer. This at least one polymer may be a natural polymer or a synthetic polymer. In certain embodiments, the at least one polymer is a synthetic polymer. Synthetic polymers are widely used in implantable medical devices. Examples of synthetic polymers that can be included in nitric oxide polymer materials include, but are not limited to, polylactic acid (PLA), polyglycolic acid (PGA), poly(lactic acid-coglycolic acid) (PLGA), polycaprolactone (PCL), thermoplastic polyurethane (TPU), and blends thereof.

[0033] In addition, or also, at least one natural polymer may be included in the polymer material that produces nitric oxide. Such natural polymers may act as cell-binding motifs and promote cell adhesion and / or proliferation. Examples of natural polymers that can be included in the polymer material that produces nitric oxide include, but are not limited to, gelatin, chitin, or collagen. In some embodiments, the polymer material that produces nitric oxide comprises only a synthetic polymer or a blend of synthetic polymers. In some embodiments, the polymer material that produces nitric oxide may comprise a blend of at least one natural polymer and at least one synthetic polymer.

[0034] At least one polymer may be a biocompatible polymer. In other words, at least one polymer may be compatible with living cells. In certain embodiments, the polymers present in the nitric oxide-producing polymer material are biocompatible. If multiple polymers are present, each polymer present in the nitric oxide-producing polymer material may be biocompatible. In some embodiments, at least one polymer is a biodegradable or bioabsorbable polymer. In other words, at least one polymer can decompose when exposed to a biological environment, such as cells or tissues of interest, and be absorbed into the body over time. In certain embodiments, the polymers present in the nitric oxide-producing polymer material are biodegradable or bioabsorbable. If multiple polymers are present, each polymer present in the nitric oxide-producing polymer material may be biodegradable or bioabsorbable.

[0035] The polymer may be an electrospinning polymer for forming one or more electrospinned fibers. Polymers suitable for electrospinning are known in themselves. Examples include poly(lactic acid-coglycolic acid) (PLGA), polycaprolactone (PCL), thermoplastic polyurethane (TPU), polymers that can act as cell-binding motifs (including, but not limited to, gelatin or collagen), and blends thereof.

[0036] In some embodiments, the polymer is a proton-source polymer. The proton source may be an acid polymer or an acid precursor polymer. An "acid precursor polymer" is a polymer species that can undergo a chemical reaction to supply an acid species. For example, an acid precursor polymer may be a polymer species that can undergo hydrolysis to supply an acid species. In other words, an acid precursor polymer may be a hydrolyzable acid precursor polymer that releases acid upon hydrolysis. For example, an acid precursor polymer may be a polyester. An acid precursor polymer may be a photoacid. In other words, an acid precursor polymer may be a species that absorbs light and becomes more acidic. To avoid doubt, the term "photoacid" as used herein includes species that undergo reversible proton photodissociation and species that undergo irreversible proton photodissociation. Examples of such proton-source polymers include, but are not limited to, polyacrylic acid (particularly partially neutralized polyacrylic acid) and polyester (particularly PLGA).

[0037] Particles or aggregates of particles containing nitrite components and proton source components. In some embodiments, the implantable medical device of the present invention comprises particles or aggregates of particles containing a nitrite component and a proton source component in a single polymer material that generates nitric oxide. Thus, the single polymer material that generates nitric oxide may release nitric oxide by acidification of the nitrite when exposed to an aqueous environment or moisture in the atmosphere.

[0038] Components of solid nitrite A nitrite is listed as a component of solid nitrite. The choice of nitrite is not particularly limited. The nitrite can be selected from one or more alkali metal nitrites or alkaline earth metal nitrites. For example, one or more nitrites can be selected from LiNO2, NaNO2, KNO2, RbNO2, CsNO2, FrNO2, AgNO2, Be(NO2)2, Mg(NO2)2, Ca(NO2)2, Sr(NO2)2, Mn(NO2)2, Ba(NO2)2, Ra(NO2)2, and any mixture thereof. The nitrite may be NaNO2 or KNO2. The nitrite may be NaNO2.

[0039] The nitrite may be of a pharmaceutically acceptable grade. In other words, the nitrite may conform to one or more active pharmacopoeia monographs relating to nitrites. For example, the nitrite may conform to one or more monographs relating to nitrites in the United States Pharmacopeia (USP), European Pharmacopoeia, or Japanese Pharmacopoeia.

[0040] In particular, the nitrite used may have one or more characteristics provided in Table 1 of paragraphs

[0032] to

[0060] and paragraph

[0204] of WO 2010 / 093746 (whose entire disclosure is incorporated herein by attribution).

[0041] Components of a solid proton source The components of the proton source include the proton source itself. The proton source may be any species that has the ability to act as a source of protons for acidifying the nitrite. The choice of proton source is not particularly limited. The proton source may be, for example, an acid.

[0042] Components of a solid proton source may be provided as components of a solid proton source. In addition, or also, components of a solid proton source may be provided as part of a polymer (for example, as a polymer of a proton source). The acid may be selected from one or more organic carboxylic acids or organic non-carbone reducing acids.

[0043] In this specification, the term "organic carboxylic acid" refers to any organic acid containing one or more -COOH groups in its molecule. Organic carboxylic acids may be linear or branched. They may be saturated or unsaturated. They may be aliphatic or aromatic. They may be acyclic or cyclic. They may be vinyl carboxylic acids.

[0044] Organic carboxylic acids may have one or more substituents, such as one or more hydroxyl groups. Examples of hydroxyl-substituted organic carboxylic acids that can be used in this disclosure include α-hydroxycarboxylic acids, β-hydroxycarboxylic acids, and γ-hydroxycarboxylic acids.

[0045] In this specification, the term "organic non-carbone reducing acid" refers to any organic reducing acid that does not contain a -COOH group in its molecule. Organic non-carbone reducing acids may be linear or branched. Non-carbone reducing acids may be saturated or unsaturated. Non-carbone reducing acids may be aliphatic or aromatic. Non-carbone reducing acids may be acyclic or cyclic. Non-carbone reducing acids may be vinyl-based.

[0046] The organic non-carbone reducing acid may have one or more substituents, for example, one or more hydroxyl groups. An example of a hydroxyl-substituted organic non-carbone reducing acid that can be used in this disclosure is an acidic reductone, for example, reductic acid (2,3-dihydroxy-2-cyclopentanone). One or more organic carboxylic acids or non-carbone reducing acids may have a pKa1 less than about 7.

[0047] One or more organic carboxylic acids may include, be composed of, or be themselves one or more reducing carboxylic acids. The organic carboxylic acids may be selected from, for example, salicylic acid, acetylsalicylic acid, acetic acid, citric acid, glycolic acid, mandelic acid, tartaric acid, lactic acid, maleic acid, malic acid, benzoic acid, formic acid, propionic acid, α-hydroxypropanoic acid, β-hydroxypropanoic acid, β-hydroxybutyric acid, β-hydroxy-β-butyric acid, naphthoic acid, oleic acid, palmitic acid, pamoic acid (envoicic acid), stearic acid, malonic acid, succinic acid, fumaric acid, glucoheptonic acid, glucuronic acid, lactobioic acid, cinnamic acid, pyruvic acid, orotic acid, glyceric acid, glycyrrhizic acid, sorbic acid, hyaluronic acid, alginic acid, oxalic acid, salts thereof, and combinations thereof.

[0048] The organic carboxylic acid may be citric acid or a salt thereof. The carboxylic acids may include polymeric or polymerized carboxylic acids such as polyacrylic acid, polymethacrylic acid, copolymers of acrylic acid and methacrylic acid, polybutyric acid, polyglycolic acid, or copolymers of butyric acid and glycolic acid. As used herein, the term “organic carboxylic acid” also includes partial or complete esters of organic carboxylic acids or their partial or complete salts, provided that they can function as a proton source when used in accordance with the present invention.

[0049] Organic non-carbone reducing acids may be selected from, for example, ascorbic acid; ascorbate palmitic acid (ascorbyl palmitate); ascorbate derivatives such as 3-O-ethyl ascorbic acid, other 3-alkyl ascorbic acids, 6-O-octanoyl ascorbic acid, 6-O-dodecanoyl ascorbic acid, 6-O-tetradecanoyl ascorbic acid, 6-O-octadecanoyl ascorbic acid, and 6-O-dodecanediol ascorbic acid; acidic redactones such as reductic acid; erythorbic acid; salts thereof; and combinations thereof.

[0050] The organic non-carbone reducing acid may be ascorbic acid or a salt thereof. One or more proton sources of organic carboxylic acids or organic non-carbone reducing acids may be present together with their conjugate bases, if appropriate. The acid and its conjugate base may be able to form a buffer when in contact with or exposed to an aqueous environment. The acid and its conjugate base may be provided in proportions that achieve a desired pH when exposed to an aqueous environment.

[0051] The buffer system may be selected so that, when exposed to an aqueous environment, the desired pH is achieved and the reaction that produces NOx proceeds and is maintained. The buffer system may be selected so that the pH of the reaction is in the range of about 3 to 9, for example, about 4 to 8. In physiological contact, or when in contact with living cells and organisms, the pH of the reaction may be in the range of about 5 to about 8. The conjugate base, if present, may be added separately, or may be generated in situ from a proton source by adjusting the pH with an acid and / or base, for example, a mineral acid and / or a mineral base. The proton source may be a citrate / citrate buffer system, for example, a citrate / trisodium citrate buffer system.

[0052] The proton source may be an acid precursor, or may contain an acid precursor. An "acid precursor" is a species that can undergo a chemical reaction to provide an acid species. For example, an acid precursor may be a species that can undergo hydrolysis to provide an acid species. In other words, an acid precursor may be hydrolyzable and release acid upon hydrolysis. For example, an acid precursor may be an ester. An acid precursor may be a photoacid. In other words, an acid precursor may be a species that absorbs light to become more acidic. To avoid ambiguity, the term "photoacid" as used herein includes species that undergo reversible proton photodegradation and species that undergo irreversible proton photodegradation.

[0053] Solid proton source components can be provided as polymer components of a polymer material (for example, as a proton source polymer). In some embodiments, solid proton source components encompass proton source fibers. In other words, the term proton source components encompass fibers having proton-supplying capabilities. Such proton source fibers include, but are not limited to, polyacrylic acid fibers (particularly partially neutralized polyacrylic acid fibers) and polyester fibers (particularly PLGA fibers).

[0054] In certain embodiments, the components of the solid proton source may include a combination of components of the solid powder proton source and proton source fibers. In certain embodiments, the components of a solid proton source encompass the components of a solid powder proton source. Those skilled in the art will understand that the choice of acid components / proton source can be selected according to the desired application.

[0055] Combination of solid nitrite components and solid proton source components The components of a solid proton source and the components of a solid proton source may be provided in the form of one or more particles, each containing a nitrite and a proton source. It should be understood that when a particle contains both a proton source and a nitrite, the particle may contain both the nitrite and the proton source within the same particle. The particles, each containing a nitrite and a proton source, may be provided as individual particles in a polymer material that generates nitric oxide, and / or as aggregates of particles, where each of the one or more particles in the aggregate contains a nitrite and a proton source.

[0056] In addition, or also, the components of the solid nitrite and the components of the solid proton source may be provided as aggregates of one or more particles containing nitrite but not the proton source, and one or more particles containing the proton source but not the nitrite. It should be recognized that the particles may contain either the nitrite or the proton source within the same particle, or may not contain either the nitrite or the proton source. One or more particles containing either the nitrite or the proton source may be blended to obtain a substantially homogeneous mixture of particles.

[0057] In this specification, the terms “aggregate,” “aggregate,” and “aggregated together” refer to the aggregation or assembly of primary (individual) particles exhibiting identifiable collective behavior.

[0058] In the present invention, aggregates of individual particles include (i) individual particles containing a nitrite and individual particles containing a proton source, (ii) individual particles containing a nitrite and a proton source, or (iii) a combination thereof, and may optionally include a binder. In the present invention, identifiable collective behavior may refer to resistance to mechanical separation, that is, adhesion between particles.

[0059] The particles or aggregates of the solid nitrite component and the solid proton source component may have a particle size suitable for the desired use or application. For example, the particles or aggregates of the solid composition may have a particle size of about 10 μm or less, for example, about 5 μm or less, about 4 μm or less, about 3 μm or less, about 2 μm or less, or about 1 μm or less.

[0060] Alternatively, the particles or aggregates of the solid nitrite component and the solid proton source component may have a particle size greater than 5 μm. For example, the particles or aggregates of the solid composition may have a particle size greater than 50 μm, greater than 100 μm, greater than 250 μm, greater than 500 μm, greater than 750 μm, or greater than 1000 μm.

[0061] The weight ratio of nitrite to proton source in a mixture of solid nitrite components and solid proton source components may be in the range of approximately 1:1 to approximately 1:99, such that it is in the range of approximately 1:4 to approximately 1:49 or approximately 1:7 to approximately 1:24. The mixture of the solid nitrite component and the solid powder proton source component may contain further optional additives such as a binder (as shown above) or an organic polyol.

[0062] Binder A mixture of a solid nitrite component and a solid proton source component may substantially contain one or more binders. Alternatively, a mixture of a solid nitrite component and a solid proton source component may further contain one or more binders. As used herein, "binder" refers to an agent that promotes the adhesion of particles, that is, promotes the formation of particle aggregates.

[0063] Suitable binders include sugars, natural binders, or synthetic or semi-synthetic polymer binders. Sugar species may include, for example, sucrose or liquid glucose. Natural binders may include, for example, acacia, tragacanth, gelatin, starch lake, pregelatinized starch, alginic acid, or cellulose. Synthetic or semi-synthetic polymer binders may include, for example, methylcellulose, ethylcellulose, hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose, sodium carboxymethylcellulose, polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), polyvinyl alcohol, or polymethacrylate. The binder may also be a copolymer of 1-vinyl-2-pyrrolidone and vinyl acetate (copovidone). The binder may also be microcrystalline cellulose.

[0064] The binder may be added to the mixture of the solid nitrite component and the solid proton source component at a %w / w concentration of approximately 5%w / w to approximately 30%w / w. For example, the binder may be added to the mixture of the solid nitrite component and the solid proton source component at a %w / w concentration of approximately 10%w / w to approximately 25%w / w.

[0065] Organic polyols A mixture of a solid nitrite component and a solid proton source component may substantially contain one or more organic polyols. Alternatively, the mixture of a solid nitrite component and a solid proton source component may further contain one or more organic polyols. If the mixture of a solid nitrite component and a solid proton source component contains one or more organic polyols, it is preferable to add the organic polyol to the mixture of a solid nitrite component and a solid proton source component after any treatment including solvent removal (e.g., after a spray-drying or freeze-drying step). In other words, the polyol may be added to a composition containing one or more particles containing nitrite and a proton source (either before or after the formation of aggregates of the particles described below); or to a mixture containing one or more particles containing nitrite and / or one or more particles containing a proton source.

[0066] In this specification, the term "organic polyol" refers to an organic molecule having two or more hydroxyl groups that is not a proton source, particularly not a proton source for nitrite reactions, and is not a sugar or polysaccharide (the terms "sugars" and "polysaccharides" include oligosaccharides, glycans, and glycosaminoglycans). Thus, organic polyols will have a pKa1 of approximately 7 or higher.

[0067] In this specification, the term "organic polyol" is preferably used to exclude reducing agents. Examples of reducing agents that are organic molecules having two or more hydroxyl groups and are not sugars or polysaccharides include thioglycerol (e.g., 1-thioglycerol), hydroquinone, butylated hydroquinone, ascorbic acid, ascorbate, erythorbic acid, and erythorbate. Thus, thioglycerol (e.g., 1-thioglycerol), hydroquinone, butylated hydroquinone, ascorbate, and erythorbate are preferably excluded from the term "organic polyol" because they are reducing agents. Ascorbic acid and erythorbic acid are excluded from the term in any case because they are proton sources, particularly proton sources for nitrite reactions.

[0068] The organic polyol may be cyclic or acyclic, or a mixture of one or more cyclic organic polyols and one or more acyclic organic polyols. For example, one or more organic polyols may be selected from one or more alkanes substituted with two or more OH groups, one or more cycloalkanes substituted with two or more OH groups, one or more cycloalkylalkanes substituted with two or more OH groups, or any combination thereof. The organic polyol may not have any substituents other than OH groups.

[0069] One or more organic polyols may be one or more acyclic organic polyols. One or more acyclic organic polyols may be selected from sugar alcohols having 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms. One or more acyclic organic polyols may be selected from algitols, e.g., algitols having 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms. One or more organic polyols may not contain saponins, sapogenins, steroids, or steroid glycosides.

[0070] Alternatively, one or more organic polyols may comprise one or more cyclic organic polyols. These cyclic organic polyols may be cyclic sugar alcohols or cyclic algitols. For example, one or more cyclic polyols may be cyclic sugar alcohols having 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms, or cyclic algitols having 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms. Inositol is a specific example of a cyclic polyol.

[0071] One or more organic polyols may have seven or more hydroxyl groups. One or more organic polyols may be sugar alcohols or alditols having seven or more hydroxyl groups. One or more organic polyols may have nine or more hydroxyl groups. One or more organic polyols may be sugar alcohols or alditols having nine or more hydroxyl groups. One or more organic polyols may have 20 or fewer hydroxyl groups. One or more organic polyols may be sugar alcohols or alditols having 20 or fewer hydroxyl groups. One or more organic polyols may have 15 or fewer hydroxyl groups. One or more organic polyols may be sugar alcohols or alditols having 15 or fewer hydroxyl groups. One or more organic polyols may have a number of hydroxyl groups in the range of 7 to 20, for example, in the range of 9 to 15. One or more organic polyols may contain 9, 12, 15 or 18 hydroxyl groups.

[0072] One or more organic polyols may be sugar alcohol compounds comprising one or more monosaccharide units and one or more acyclic sugar alcohol units, for example. One or more organic polyols may be sugar alcohol compounds comprising a linear chain of one or more monosaccharide units and one or more acyclic sugar alcohol units, or a branched chain of one or more monosaccharide units and one or more acyclic sugar alcohol units, for example.

[0073] As used herein, “monosaccharide unit” means a monosaccharide covalently bonded to at least one other unit (which may be another monosaccharide unit or an acyclic sugar alcohol unit) in the compound. As used herein, “acyclic sugar alcohol unit” means an acyclic sugar alcohol shared with at least one other unit (which may be another monosaccharide unit or an another acyclic sugar alcohol unit) in the compound. The units of the compound may be bonded via ether bonds. One or more monosaccharide units may be covalently bonded to other units of the compound via glycosidic bonds. Each monosaccharide unit may be covalently bonded to other units of the compound via glycosidic bonds. Sugar alcohol compounds may be glycosides having monosaccharides or oligosaccharide glycones and acyclic sugar alcohol aglycones.

[0074] Acyclic sugar alcohol units may be sugar alcohols having 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms. Acyclic sugar alcohol units may be selected from the group consisting of erythritol, treitol, arabitol, xylitol, ribitol, mannitol, sorbitol, galactitol, fusitol, iditol, and boremitol units. One or more monosaccharide units may be C5 or C6 monosaccharide units, i.e., pentose or hexose units. Each monosaccharide unit may be a C5 or C6 monosaccharide unit. One or more sugar alcohol units may be C5 or C6 sugar alcohol units. Each sugar alcohol unit may be a C5 or C6 sugar alcohol unit.

[0075] A sugar alcohol compound may consist of, for example, a unit comprising n monosaccharide units and m acyclic sugar alcohol units, where n is a natural number, m is also a natural number, and (n+m) does not exceed 10. A sugar alcohol compound may also contain a chain of n monosaccharide units terminated by one acyclic sugar alcohol unit, for example, a chain of such units (where n is an integer from 1 to 9). The chain of monosaccharide units may be covalently bonded by glycosidic bonds. Each monosaccharide unit may be covalently bonded by glycosidic bonds to another monosaccharide unit or to an acyclic sugar alcohol unit. A sugar alcohol compound may contain 1, 2, or 3 units terminated by one acyclic alcohol unit, for example, a chain of such units. 1, 2, 3, or each monosaccharide unit may be a C5 or C6 monosaccharide unit. The acyclic alcohol unit may be a C5 or C6 sugar alcohol unit. Examples of sugar alcohol compounds include, but are not limited to, isomalt, maltitol and lactitol (n=1); maltotriitol (n=2); and maltotetraitol (n=3).

[0076] Such sugar alcohol compounds may be described as sugar alcohols derived from disaccharides or oligosaccharides. As used herein, “oligosaccharide” means a sugar consisting of 3 to 10 monosaccharide units. Sugar alcohols derived from disaccharides or oligosaccharides may be synthesized (e.g., hydrogenated) from disaccharides, oligosaccharides, or polysaccharides (e.g., from hydrolysates and hydrogenated products), but are not limited to compounds synthesized from disaccharides, oligosaccharides, or polysaccharides. For example, sugar alcohols derived from disaccharides may be formed by a dehydration reaction between a monosaccharide and a sugar alcohol. One or more organic polyols may be sugar alcohols derived from disaccharides, trisaccharides, or tetrasaccharides. Examples of sugar alcohols derived from disaccharides include, but are not limited to, isomalt, maltitol, and lactitol. Examples of sugar alcohols derived from trisaccharides include, but are not limited to, maltotriitol. Examples of sugar alcohols derived from tetrasaccharides include, but are not limited to, maltotetraitol.

[0077] The organic polyol may be selected from erythritol, treitol, arabitol, xylitol, ribitol, mannitol, sorbitol, galactitol, fusitol, iditol, inositol, boremitol, isomalt, maltitol, lactitol, maltotriitol, maltotetraitol, polyglycitol, and any combination thereof. Glycerol, if present, is preferably used in combination with one or more other organic polyols, such as erythritol, treitol, arabitol, xylitol, ribitol, mannitol, sorbitol, galactitol, fusitol, iditol, inositol, boremitol, isomalt, maltitol, lactitol, maltotriitol, maltotetraitol, polyglycitol, or any combination thereof.

[0078] Many organic polyols contain one or more chiral centers and therefore exist in stereoisomerized forms. All stereoisomerized forms and optical isomers of organic polyols, as well as mixtures of isomers, are included within the scope of this invention. In particular, the D and / or L forms of any chiral organic polyol, and any mixture thereof, may be used.

[0079] Particle aggregation Particle aggregation can be achieved by any suitable means known to those skilled in the art. Particle aggregation may be achieved by mechanical means, for example, by mechanically pressing the particles. Mechanical aggregation may be achieved by pulverizing the nitrite particles and proton source particles. Alternatively, mechanical aggregation may be achieved by the particles being substantially free of static electricity.

[0080] Particle aggregation may be achieved by chemical means, such as chemically facilitating adhesion or by chemical coating. Chemical aggregation may be achieved by an adhesion promoter, such as moisture. Alternatively, chemical aggregation may be achieved by a coating material that binds the primary particles of nitrite together with the primary particles of the proton source. Suitable binders have been described above, and suitable coating materials are described in the "Coated Particles" section below.

[0081] Coating particles One or more particles of a mixture of a solid powder nitrite component and a solid powder proton source component may be coated with an excipient (also referred to herein as coated particles). The coated particles may contain nitrite and a proton source, and may include single particles coated with excipients.

[0082] Alternatively, the coated particles may also be aggregates of particles coated with an excipient, the aggregates of particles comprising (a) particles containing nitrite and a proton source, and / or (b) a mixture of one or more nitrite particles containing nitrite and one or more proton source particles containing a proton source. Thus, the coated particles contain nitrite and a proton source within the same coating.

[0083] The excipient may be hydrophobic. The excipient may be any material having the ability to coat particles or aggregates so that the particles or aggregates are coated with a hydrophobic layer. The hydrophobic material may be a polymer material, such as an organic polymer material such as a polyol. The hydrophobic material may be an amphiphilic species, such as a surfactant species such as a nonionic, anionic, cationic, or amphoteric surfactant species. The hydrophobic material may be an inorganic mineral material, such as an inorganic mineral material that forms a 3D framework. The hydrophobic material may be biocompatible. The hydrophobic material may include one or more poly(lactic acid-coglycolic acid) (PLGA), phospholipids such as dipalmitoylphosphatidylcholine (DPPC), magnesium stearate, and mesoporous silica. The hydrophobic material may include poly(lactic acid-coglycolic acid) (PLGA) as a polymer material without acid-terminated groups, or it may include poly(lactic acid-coglycolic acid) (PLGA) as a polymer material with acid-terminated groups. The excipients may include polyols, magnesium stearate, and colloidal silica.

[0084] As used herein, "surfactant" refers to a surfactant that can reduce the surface tension of a species in a medium or the interfacial tension between media. Surfactant species generally have a hydrophilic head and a hydrophobic tail. Hydrophobic materials can adhere to particles or aggregates by chemical bonding, electrostatics, or intermolecular forces.

[0085] The coating on coated particles or aggregates of coated particles may affect the reaction kinetics, such as the reaction kinetics of nitrite acidification, when the coated particles or aggregates are exposed to an aqueous environment. The excipients may be species that have the ability to capture or sequester nitric oxide or nitric oxide precursors. For example, the excipients may include thiols, alcohols, amines, or amides.

[0086] The coated particles or aggregates of the mixture of the solid nitrite component and the solid proton source component may have a particle size appropriate for the desired use or application. The coated particles or aggregates of the mixture of the solid nitrite component and the solid proton source component may have a particle size of about 10 μm or less, for example, about 5 μm or less, about 4 μm or less, about 3 μm or less, about 2 μm or less, or about 1 μm or less. Alternatively, the coated particles or aggregates of the mixture of the solid nitrite component and the solid proton source component may have a particle size greater than about 5 μm. For example, the particles or aggregates of the mixture of the solid nitrite component and the solid proton source component may have a particle size greater than about 50 μm, greater than about 100 μm, greater than about 250 μm, greater than about 500 μm, greater than about 750 μm, or greater than about 1000 μm.

[0087] Formation of particles from a mixture containing a nitrite solution and a proton source solution A mixture of solid nitrite components and solid proton source components can be formed by spray-drying or freeze-drying a mixture containing the nitrite solution and the proton source solution.

[0088] Particles of a mixture of solid nitrite components and solid proton source components can be formed from a mixture containing a nitrite solution and a proton source solution. These particles must be formed by removing the solvent quickly (e.g., within 30 seconds) after mixing the nitrite solution and the proton source solution, and / or by placing the mixture under reaction-inhibiting conditions (e.g., at a temperature below the freezing point of the solvent) to remove the solvent after mixing the nitrite solution and the proton source solution. In this way, the solvent is removed from the mixture while minimizing the acidification of the nitrite. Therefore, an effective amount of nitrite and proton source may be present in the resulting powder composition.

[0089] When the solvent is removed quickly after mixing the nitrite solution and the proton source solution, the solvent may be removed within 30 seconds after mixing. In some examples, the solvent is removed within 10 seconds, 5 seconds, 2 seconds, or 1 second after mixing the nitrite solution and the proton source solution. In some examples, the solvent is removed within 500 milliseconds, 100 milliseconds, 50 milliseconds, or 10 milliseconds after mixing the nitrite solution and the proton source solution.

[0090] In one example, particles can be formed by spray-drying a mixture containing a nitrite solution and a proton source solution. By spray-drying the mixture, the solvent can be removed within 30 seconds after mixing the nitrite solution and the proton source solution. Spray-drying of materials is well known.

[0091] The mixture is typically a mixture of an aqueous solution of nitrite and an aqueous solution of a proton source. When aqueous solutions are used, the time between mixing the two aqueous solutions should be minimized to suppress the acidification of the nitrite. The aqueous solutions of nitrite and acid can be mixed inline for about 1 to 10 milliseconds, for example, about 3 to 5 milliseconds, before spray drying. Spray drying may be performed immediately after mixing the nitrite solution and the acid solution. As described, it is understood that mixing and spray drying a mixture containing a nitrite solution and a proton source solution limits the time available for reaction between the proton source and the nitrite components.

[0092] The particles formed by spray-drying a mixture containing a nitrite solution and an acid solution may have a particle size of approximately 10 μm or less, for example, approximately 5 μm or less, approximately 4 μm or less, approximately 3 μm or less, approximately 2 μm or less, or approximately 1 μm or less. As described, a mixture containing a nitrite solution and an acid solution is spray-dried to obtain a mixture of solid powder nitrite components and solid powder proton source components, where each particle contains the nitrite and proton source components.

[0093] The particles formed by spray-drying a mixture containing a nitrite solution and a proton source solution may be in any suitable form. For example, the particles formed by spray-drying a mixture containing a nitrite solution and a proton source solution may be in a crystalline or amorphous form.

[0094] In addition, or by alternative means, the mixture of the nitrite solution and the proton source solution is placed under reaction-inhibiting conditions (e.g., a temperature below the freezing point of the solvent) to remove the solvent before, during, or immediately after mixing. In this way, the acidification of the nitrite is suppressed until the solvent is removed. In particular, the solvent may be an aqueous solvent.

[0095] A specific example of reaction-inhibiting conditions is to keep the temperature of the mixture below the freezing point of the solvent. In this way, the reaction rate of nitrite acidification can be slowed while removing the solvent. When the temperature of the mixture is below the freezing point of the solvent, the nitrite solution and the proton source solution are typically mixed at a temperature above the freezing point of the solvent, and then the temperature of the mixture is lowered to below the freezing point of the solvent. In this manner, good mixing of the solutions can occur.

[0096] In some embodiments, solvent removal may occur in a low-pressure gaseous state. In particular, solvent removal may occur in combination with a low-pressure gaseous state and a temperature below the freezing point of the solvent being removed. Freeze-drying (also known as "freeze drying") is a particularly useful technique for removing solvents under reaction-inhibiting conditions.

[0097] It should be noted that the terms “solvent removal” and / or “drying” are used herein to refer to obtaining a solid powder composition. These terms include, but are not limited to, the complete removal of the solvent. In some examples, the solid powder composition may contain trace amounts of residual solvent. For example, the powder composition may contain up to about 10% of the residual solvent, up to about 5%, up to about 3%, or up to about 1%. Additional drying techniques, such as vacuum drying, may be used after the solvent has been initially removed to obtain the solid powder composition.

[0098] A combination of solids for forming aggregates of particles A mixture of a solid nitrite component and a solid proton source component may be formed by combining a nitrite-containing solid with a proton source-containing solid to form a particle aggregate, where the particle aggregate comprises one or more particles containing nitrite and one or more particles containing the proton source.

[0099] The formation of particle aggregates by combining a nitrite-containing solid with a proton source-containing solid can be achieved, for example, (a) by blending one or more nitrite particles with one or more proton source particles, where the nitrite particles are formed by spray-drying a nitrite solution and the proton source particles are formed by spray-drying a proton source solution; or (b) by forming one or more particles by pulverizing the nitrite solid together with the proton source solid.

[0100] A blend of spray-dried nitrite particles and spray-dried acid particles. A mixture of solid nitrite components and solid proton source components is (i) The solution containing nitrite is spray-dried or freeze-dried, (ii) The solution containing the proton source is spray-dried or freeze-dried. (iii) Blend the seeds of (i) and (ii). It may be formed by...

[0101] A mixture of solid nitrite components and solid proton source components may be a blend of nitrite particles and proton source particles, where the nitrite particles are formed by spray-drying a nitrite solution, and the proton source particles are formed by spray-drying a proton source solution. The spray-dried nitrite particles and spray-dried proton source particles can be blended by standard means known to those skilled in the art to obtain a blended solid composition.

[0102] Spray-dried nitrite particles and spray-dried proton source particles can be blended in a weight ratio of approximately 1:1 to 1:99, with the nitrite ratio being in the range of approximately 1:4 to 1:49 or approximately 1:7 to 1:24.

[0103] The spray-dried nitrite particles and the spray-dried proton source particles may be blended for a period of time of approximately 5 to 60 minutes, for example, for approximately 10 to 40 minutes, or for approximately 15 to 30 minutes. The spray-dried nitrite particles and the spray-dried proton source particles may also be blended over a period of approximately 20 minutes.

[0104] As described above, the particles formed by spray-drying the nitrite solution and the acid solution and blending these components may have a particle size of about 10 μm or less, for example, about 5 μm or less, about 4 μm or less, about 3 μm or less, about 2 μm or less, or about 1 μm or less.

[0105] As described above, by spray-drying the nitrite solution and the proton source solution, and blending these components, a mixture of solid nitrite components and solid proton source components can be obtained, which contains aggregates of particles, where the aggregates contain one or more particles containing nitrite and one or more particles containing the proton source.

[0106] The particles formed by spray-drying a nitrite solution and a proton source solution, and then blending these components, may be in any suitable form. For example, the particles formed by spray-drying a nitrite solution and a proton source solution, and then blending these components, may be crystalline or amorphous in form. The particles obtained by spray-drying a mixture containing a nitrite solution and a proton source solution may be amorphous in form.

[0107] Particles formed by pulverizing nitrite solids together with acid solids. The particles may also be formed by pulverizing a nitrite solid together with an acid solid. As used herein, the term "micronization" refers to a process that reduces the average particle size of a solid composition to a range typically on the micrometer scale. Micronization can be achieved by standard processes known to those skilled in the art. For example, micronization may occur by grinding or abrading particles, or by utilizing supercritical fluids.

[0108] If the proton source is an acid buffer system, the proton source solid may consist of two components: a solid acid component and a solid conjugated base component. The nitrite solid and the proton source solid may be pulverized in a ratio of approximately 1:1 to approximately 1:99, such as 1:4 to approximately 1:49 or approximately 1:7 to approximately 1:24, for example, with a nitrite:proton source ratio of 1:9 w / w. The particles formed by pulverizing the nitrite solid together with the proton source solid may have a particle size of approximately 10 μm or less, for example, approximately 5 μm or less, approximately 4 μm or less, approximately 3 μm or less, approximately 2 μm or less, or approximately 1 μm or less.

[0109] As described above, a solid powder composition containing nitrite-containing particles and proton source-containing particles can be obtained by micronizing a nitrite solution together with a proton source solution. As described above, a solid powder composition consisting of aggregates containing nitrite-containing particles and proton source-containing particles can also be obtained by micronizing a nitrite solution together with a proton source solution. The particles formed by pulverizing the nitrite solution together with the proton source solution may be in any suitable form. For example, the particles formed by pulverizing the nitrite solution together with the proton source solution may be in a crystalline or amorphous form. The particles formed by pulverizing the nitrite solution together with the proton source solution may be in a crystalline form.

[0110] The particles formed by micronization may contain one or more optional additives (in addition to the proton source and nitrite) as described above. In particular, the particles formed by micronization may contain a binder as described above. The binder can be micronized together with the nitrite solid and the proton source solid.

[0111] If the polymer material that generates nitric oxide contains particles or aggregates of particles, the particles or aggregates of particles may be incorporated into or encapsulated within the polymer of the nitric oxide-generating polymer material. In this way, the particles or aggregates of particles may be retained within the material by the polymer until exposed to moisture or an aqueous environment. The particles or aggregates of particles may be exposed or partially exposed on the outer surface of the polymer of the nitric oxide-generating polymer material, or they may be completely encapsulated within the polymer of the nitric oxide-generating polymer material.

[0112] The polymer material that generates nitric oxide may be a fibrous material comprising polymer fibers and particles or aggregates of particles incorporated into or encapsulated within the fibrous material. The particles or aggregates of particles may be exposed or partially exposed on the surface of the base fibers, or they may be completely encapsulated within the fiber network and fiber cross-section.

[0113] In some embodiments, the polymer material that generates nitric oxide is porous, and at least some particles or aggregates of solid nitrite components and / or solid proton source components are present within the pores of the material. In other words, the material is porous and may be impregnated with particles or aggregates of solid nitrite components and / or solid proton source components. In some embodiments, the material is porous by containing pores on its surface. In other embodiments, the material is a porous mesh of material elements such as polymer fibers, and particles or aggregates of particles may be present in the voids between the material elements. As a specific example, particles or aggregates of solid nitrite components and / or solid proton source components may be impregnated into the voids of a polymer fiber mesh.

[0114] The particles or aggregates of the solid nitrite component and / or the solid proton source component may have a particle size suitable for dispersion in the gelling fibers. The particles or aggregates of the solid nitrite component and / or the solid proton source component may have a particle size larger than about 5 μm. For example, the particles or aggregates of the solid nitrite component and / or the solid proton source component may have a particle size larger than about 50 μm, larger than about 100 μm, larger than about 250 μm, larger than about 500 μm, larger than about 750 μm, and larger than about 1000 μm.

[0115] To obtain larger particle sizes, the particles or aggregates of particles may undergo a granulation process. Granulation is the process of combining finer particles to form larger particles known as granules. Granulation may be carried out, for example, by compressing the particles or aggregates to obtain a tablet that can then be ground into granules. The particles or aggregates may be compressed to about 1 to about 10 metric tons (MT), for example, to about 3 to about 7 MT. The particles or aggregates may be compressed to about 3.8 MT. The particles or aggregates may be compressed to about 6.5 MT. The tablets may be crushed into granules using a sieve, for example, a 1 mm sieve.

[0116] To promote compression, a binder may be added to the particles or aggregates. Suitable binders include sugars and natural, synthetic, or semi-synthetic polymer binders. Examples of sugars include sucrose or liquid glucose. Examples of natural binders include acacia, tragacanth, gelatin, starch paste, pregelatinized starch, alginic acid, and cellulose. Examples of synthetic or semi-synthetic polymer binders include methylcellulose, ethylcellulose, hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose, sodium carboxymethylcellulose, polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), polyvinyl alcohol, and polymethacrylate. The binder may also be a copolymer of 1-vinyl-2-pyrrolidone and vinyl acetate (copovidone). The binder may also be microcrystalline cellulose.

[0117] The binder may be incorporated into the composition at a %w / w concentration of approximately 5% w / w to approximately 30% w / w. For example, the binder may be incorporated into the composition at a %w / w concentration of approximately 10% w / w to approximately 25% w / w. Alternatively, the composition may be substantially free of binders. The particle size may be increased by such means to ensure that the particles or aggregated particles remain trapped (integrated or encapsulated) between the fibers.

[0118] Particles or aggregates of solid nitrite components and / or solid proton source components may be incorporated into a polymer material when producing a nitric oxide-producing polymer material. A method for incorporating or encapsulating particles or aggregates of solid nitrite components and / or solid proton source components into a nitric oxide-producing polymer material includes (i) mixing particles or aggregates of solid nitrite components and / or solid proton source components with a polymer-containing nonpolar liquid to form a liquid-particle mixture, and (ii) solidifying the liquid-particle mixture to form a material into which the particles or aggregates of solid nitrite components and / or solid proton source components are incorporated or encapsulated.

[0119] Liquid-particle mixtures can be solidified by spinning the mixture into fibers. Techniques known to those skilled in the art for spinning fibers may be used. For example, liquid-particle mixtures may be solidified by dry spinning, wet spinning, gel spinning, or electrospinning. Liquid-particle mixtures may be solidified by electrospinning. "Electrospinning" refers to a method of producing fibers in which an charged thread of a polymer solution or polymer molten material is drawn to the fiber diameter using electric force. Liquid-particle mixtures may be solidified by gel spinning. "Gel spinning" refers to a method of producing fibers that relies on temperature-induced physical gelation for solidification.

[0120] Alternatively, particles or aggregates of solid nitrite components and / or solid proton source components may be incorporated into the polymer material after the solid polymer has been formed. For example, particles or aggregates of solid nitrite components and / or solid proton source components may be impregnated into a porous polymer material such as a fibrous mesh substrate. In these examples, the solid polymer has already been formed, and particles or aggregates of solid nitrite components and / or solid proton source components are added thereto. Specific examples of methods for impregnating a porous polymer material with a solid powder composition include the method described in EP2331309 (and other techniques available from Fibroline France).

[0121] Nitrite dissolved in a polymer matrix In some embodiments, the nitrite component is dissolved in the polymer matrix of the proton-source polymer. In certain embodiments, the nitrite component is substantially homogeneously dissolved in the polymer matrix. The nitrite components and proton source polymers are as described herein. Methods for dissolving the nitrite components in the polymer matrix include dissolving the nitrite components in a polar solvent such as methanol and mixing them together with a polar solution of the polymer (such as dimethyl sulfoxide or DMSO). In certain embodiments, the mixing provides a substantially homogeneous mixture of the nitrite components and the polymer.

[0122] The optimal solvent for dissolving nitrite components and polymers is typically selected so that the solution containing the nitrite source and the polymer are miscible, the solute remains soluble, and the mixture is homogeneous. The solvent system may contain one or more solvents to prepare a cosolvent solution. A suitable solvent may be a single solvent or a mixture of solvents, preferably polar or polar aprotic with respect to the polymer and polar or polar protic with respect to the nitrite component. Water is not necessarily excluded as a solvent of choice for sodium nitrite, assuming that once mixed with the polymer solution, a homogeneous solution of the nitrite source and polymer can still be obtained. In some embodiments, the solvent for the nitrite component is non-aqueous, and / or the solvent for the polymer is non-aqueous.

[0123] In certain embodiments, the solvent used may be suitable for electrospinning or thermospinning, as is known to those skilled in the art. Next, the mixture of nitrite components and polymer may be formed into a polymer material that generates nitric oxide by known methods. For example, the mixture may be subjected to electrospinning or thermospinning to form fibers. Alternatively, the mixture may be coated onto a substrate. The mixture may be cast into a film. The solvent of the mixture may be removed at this stage.

[0124] Other features of implantable medical devices The implantable medical device may include one or more additional dry components or layers adjacent to the polymer material that generates nitric oxide. The water content of any component or layer adjacent to the polymer material that generates nitric oxide may be 10% or less, 5% or less, 2% or less, or 1% or less, based on the weight of the component or layer adjacent to the polymer material that generates nitric oxide.

[0125] Packaged implantable medical device The present invention also provides a packaged implantable medical device comprising the implantable medical device described herein within a low-moisture-permeability package. Low-permeability packaging materials may include one or more low-permeability materials (e.g., aluminum foil) in the walls of the packaging material. In certain embodiments, the low-permeability packaging material includes one or more low-permeability materials (e.g., aluminum foil) in the walls of the packaging material and the implantable medical device, and is sealed with high airtightness. The low-permeability packaging material may include one or more low-permeability materials (e.g., aluminum foil) in at least a portion of all of the outer walls of the packaging material.

[0126] The packaging atmosphere inside a packaged implantable medical device may have a low moisture content initially after packaging. The packaging atmosphere may have a relative humidity of 30% or less, 25% or less, 20% or less, 15% or less, or 10% or less. Relative humidity can be measured using a hygrometer. The packaging atmosphere may contain an inert packaging gas such as nitrogen, argon, helium, or CO2. The packaging atmosphere may also contain 10% or less, 8% or less, 5% or less, 2% or less, or 1% or less of oxygen. In some embodiments, the packaging atmosphere is substantially oxygen-free. In addition, or by alternative means, the packaging may include one or more pack inserts for moisture isolation. Such pack inserts may be desiccant packs, such as silica gel packs.

[0127] Method of implanting medical devices The present invention provides a method for implanting an implantable medical device as described herein. The implantable medical device may be a single-component implantable medical device. In other words, the implantable medical device may be provided as a single piece until needed. The present invention also provides particles or aggregates of particles used when implanting an implantable medical device as described herein into a subject, wherein (a) one or more individual particles each contain a nitrite and a proton source; or (b) the aggregate comprises one or more individual particles containing a nitrite, one or more individual particles containing a proton source, and optionally a binder, and / or the aggregate of particles comprises one or more individual particles, each containing a nitrite and a proton source, and optionally a binder. The implantable medical device may be a single-piece implantable medical device. In other words, the implantable medical device may be supplied as a single piece until required.

[0128] In some embodiments, the method includes adding water (including aqueous solutions, suspensions, gels, or other forms containing water) to a nitric oxide-producing polymer material before implanting an implantable medical device. The addition of water may be direct to the nitric oxide-producing polymer material or indirectly to the nitric oxide-producing polymer material (e.g., through one or more permeable components or layers adjacent to the nitric oxide-producing polymer material). The water added may be a sterile aqueous solution. The aqueous environment may be a sterile Saline solution.

[0129] Alternatively, the implantable medical device may be implanted in the subject without the addition of water. In this manner, aqueous fluids originating from the subject (e.g., blood and / or exudate) may be absorbed by the nitric oxide-generating polymer material of the implantable medical device, thereby activating nitric oxide production. The subject may be a human or an animal. The subject may be a human or a domesticated animal.

[0130] Method for manufacturing solid powder components Method for producing a solid powder composition by removing the solvent A method for producing a mixture of a solid powder nitrite component and a solid powder proton source component may include removing the solvent from the mixture of the nitrite solution and the proton source solution in such a manner to minimize acidification before the formation of the solid powder composition. In one example, the method includes the step of mixing a nitrite solution and a proton source solution to form a solid, and then removing the solvent (by spray drying) in less than 30 seconds.

[0131] In yet another embodiment, the method includes providing conditions to delay the reaction (e.g., freeze-drying) during the removal of the solvent and before, and / or immediately after, mixing the nitrite solution and the proton source solution. In one example, the method may include a step of removing the solvent from an aqueous mixture containing a nitrite solution and a proton source solution to form a solid powder.

[0132] The aqueous solution of nitrite may have a concentration in the range of approximately 0.1 M to approximately 5 M. The aqueous solution of nitrite may have a concentration of at least approximately 0.1 M, at least approximately 0.2 M, at least approximately 0.5 M, at least approximately 0.75 M, or at least approximately 1 M. The aqueous solution of nitrite may have a concentration up to approximately 5 M, up to approximately 4 M, up to approximately 3 M, or up to approximately 2 M. For example, the aqueous solution of nitrite may have a concentration in the range of approximately 1 M to approximately 2 M, such as approximately 1.5 M. The pH of the aqueous solution of nitrite may be approximately 6.5 to approximately 9, for example, approximately 7 to approximately 8.

[0133] The aqueous solution of the proton source may have a concentration in the range of about 0.1 M to about 5 M. The aqueous solution of nitrite may have a concentration of at least about 0.1 M, at least about 0.2 M, at least about 0.5 M, at least about 0.75 M, or at least about 1 M. The aqueous solution of nitrite may have a concentration up to about 5 M, up to about 4 M, up to about 3 M, or up to about 2 M. For example, the aqueous solution of nitrite may have a concentration in the range of about 0.5 M to about 1.5 M, such as about 1 M. The aqueous solution of citric acid may have a pH of about 4 to 6. The pH of the aqueous solution of the proton source may be adjusted using an inorganic base such as sodium hydroxide.

[0134] In some examples, the solvent removal step requires 20 seconds or less, 10 seconds or less, 5 seconds or less, 2 seconds or less, or 1 second or less after mixing the nitrite solution and the proton source solution. In some examples, the solvent is removed within 500 milliseconds, within 100 milliseconds, within 50 milliseconds, or within 10 milliseconds after mixing the nitrite solution and the proton source solution.

[0135] spray drying A mixture of a solid powder nitrite component and a solid powder proton source component can be produced by spray-drying the nitrite solution and the proton source solution. The aqueous solutions of nitrite and acid may be mixed inline for about 1 to 10 milliseconds, for example, about 3 to 5 milliseconds, before spray drying. Spray drying may be performed immediately after mixing the nitrite and proton source solutions. As described, mixing the mixture containing the nitrite solution and the proton source solution, and then spray drying, is understood to greatly limit the potential reaction time between the proton source and the nitrite components, so that the reaction stops completely when the water is rapidly removed.

[0136] Spray drying may be performed at an outlet temperature in the range of approximately 60 to 80°C, such as approximately 65 to 75°C or approximately 68 to 70°C. Spray drying may be performed at a spray pressure in the range of approximately 1 to 6 bar. Spray drying may be performed at a liquid supply rate in the range of approximately 1 to 5 g / min, such as approximately 2 g / min to 4 g / min or approximately 3 g / min.

[0137] Reaction suppression conditions Alternatively, the method may include providing reaction-inhibiting conditions (e.g., freeze-drying) during the removal of the solvent, and before, during, and / or immediately after mixing the nitrite solution and the proton source solution. A specific example of reaction-inhibiting conditions is to lower the temperature of the mixture below the freezing point of the solvent. In this way, the reaction rate of acidification of nitrite can be slowed while the solvent is removed. When the temperature of the mixture is below the freezing point of the solvent, the nitrite solution and the proton source solution are typically mixed at a temperature above the freezing point of the solvent, and then the temperature of the mixture is lowered to a temperature below the freezing point of the solvent. In this way, good mixing of the solutions may occur.

[0138] In some embodiments, solvent removal may be carried out under low gas pressure. In particular, solvent removal may be carried out at low gas pressure in combination with a temperature below the freezing point of the solvent being removed. A particularly useful technique for removing solvents under reaction-inhibiting conditions is freeze-drying (also known as "freeze-drying").

[0139] The time required to remove the solvent after mixing the nitrite solution and the proton source solution under reaction-suppressing conditions is approximately 10 minutes or less. Under these conditions, such rapid removal of the solvent (e.g., water) may not be of much importance. However, removal of the solvent in a relatively short time frame is also desirable to further limit the acidification of the nitrite. In some examples, the solvent is removed approximately 8 minutes or less, for example, approximately 7 minutes or less, approximately 6 minutes or less, approximately 5 minutes or less, approximately 4 minutes or less, approximately 3 minutes or less, or approximately 2 minutes or less, after mixing the nitrite solution and the proton source solution under reaction-suppressing conditions. In further examples, the step of removing the solvent is carried out approximately 1 minute or less, approximately 30 seconds or less, approximately 20 seconds or less, approximately 15 seconds or less, or approximately 10 seconds or less, after mixing the nitrite solution and the proton source solution.

[0140] It should be noted that the terms “solvent removal” and / or “drying” as used herein refer to obtaining a solid powder composition. These terms include, but are not limited to, the complete removal of the solvent. In some examples, the solid powder composition may contain trace amounts of residual solvent. For example, the powder composition may contain up to about 10% residual solvent, e.g., up to about 5% residual solvent, up to about 3% residual solvent, or up to about 1% residual solvent. To obtain a solid powder composition, after the solvent has been initially removed, additional drying techniques such as vacuum drying may be used.

[0141] A method for forming particle aggregates by combining particles. The formation of particle aggregates containing nitrite-containing particles and proton-containing particles can be achieved in many ways. In one embodiment, the method is (i) A step of spray-drying or freeze-drying a nitrite solution to form nitrite particles; (ii) A step of spray-drying or freeze-drying the proton source solution to form proton source particles; and (iii) A step of blending nitrite particles and proton source particles. It may include.

[0142] The aqueous solution of nitrite can have a concentration in the range of approximately 0.1 M to approximately 5 M. The aqueous solution of nitrite may have a concentration of at least approximately 0.1 M, at least approximately 0.2 M, at least approximately 0.5 M, at least approximately 0.75 M, or at least approximately 1 M. The aqueous solution of nitrite may have a concentration up to approximately 5 M, up to approximately 4 M, up to approximately 3 M, or up to approximately 2 M. For example, the aqueous solution of nitrite may have a concentration in the range of approximately 1 M to approximately 2 M, such as approximately 1.5 M. The pH of the aqueous solution of nitrite may be approximately 6.5 to approximately 9, for example, approximately 7 to approximately 8.

[0143] The aqueous solution of the proton source can have a concentration in the range of approximately 0.1 M to approximately 5 M. The aqueous solution of nitrite may have a concentration of at least approximately 0.1 M, at least approximately 0.2 M, at least approximately 0.5 M, at least approximately 0.75 M, or at least approximately 1 M. The aqueous solution of nitrite may have a concentration up to approximately 5 M, up to approximately 4 M, up to approximately 3 M, or up to approximately 2 M. For example, the aqueous solution of nitrite may have a concentration in the range of approximately 0.5 M to approximately 1.5 M, such as approximately 1 M. The aqueous solution of citric acid may have a pH of approximately 4 to 6. The pH of the aqueous solution of the proton source may be adjusted using an inorganic base such as sodium hydroxide.

[0144] Spray drying may be carried out at an outlet temperature in the range of approximately 60 to 80°C, such as approximately 65 to 75°C or approximately 68 to 70°C. Spray drying may be carried out at a spray pressure in the range of approximately 1 to 6 bar. Spray drying may be carried out at a liquid supply rate in the range of approximately 1 to 5 g / min, such as approximately 2 g / min to 4 g / min or approximately 3 g / min.

[0145] In some embodiments, the spray-dried particles are further dried, for example, by vacuum drying. Spray-dried or freeze-dried nitrite particles and spray-dried or freeze-dried proton source particles may be blended by standard means known to those skilled in the art to obtain a blended solid powder composition. Spray-dried or freeze-dried nitrite particles and spray-dried or freeze-dried proton source particles may be blended in a weight ratio of approximately 1:1 to approximately 1:99, such that the nitrite to proton source weight ratio is in the range of approximately 1:4 to approximately 1:49 or approximately 1:7 to approximately 1:24.

[0146] The spray-dried nitrite particles and the spray-dried proton source particles may be blended for a period of time of approximately 5 to 60 minutes, for example, approximately 10 to 40 minutes, or approximately 15 to 30 minutes. The spray-dried nitrite particles and the spray-dried proton source particles may also be blended for a period of approximately 20 minutes.

[0147] A method for producing a mixture of solid powder nitrite components and solid powder proton source components by micronization. A method for producing a mixture of a solid powder nitrite component and a solid powder proton source component may include the steps of pulverizing the solid nitrite and the solid proton source to produce the solid powder composition. Pulverization is known in itself. Pulverization can be achieved by standard methods known to those skilled in the art. For example, pulverization may be carried out by grinding or grinding the particles, or by utilizing a supercritical fluid.

[0148] The nitrite solid may be pulverized together with the proton source solid for about 5 to 30 minutes, for example, about 5 to 20 minutes, or about 5 to 15 minutes. The nitrite solid may be pulverized together with the proton source solid for about 10 minutes. The nitrite solid may be pulverized together with the proton source solid at a Venturi pressure of 8 bar and a grinding pressure of 2 bar.

[0149] The inventors have found that by micronizing a solid nitrite together with a solid proton source (i.e., simultaneously), a solid powder composition is obtained that, when exposed to an aqueous environment, exhibits better nitric oxide release than a solid powder composition formed by blending separately micronized nitrite powder and separately micronized proton source powder.

[0150] Method for producing a solid powder composition of coated particles A mixture of a solid powder nitrite component and a solid powder proton source component may be produced, including particles coated with a hydrophobic material. The method is one of the following: (i) A step of coating particles containing nitrite and a proton source with a hydrophobic material; or (ii) A step of combining one or more nitrite particles containing nitrite and one or more proton source particles containing a proton source, and then coating the mixture. It may include.

[0151] The hydrophobic material may be the same hydrophobic material as described above. The particles or aggregates of particles may be coated by any suitable method known to those skilled in the art. Particles or aggregates of particles can be coated by dispersing them in a solution containing a hydrophobic material and drying the solution, thereby obtaining particles or aggregates coated with a layer of hydrophobic material. In some examples, the solution contains a nonpolar solvent. In certain examples, the solution does not contain a polar solvent (e.g., methanol). Such a polar solvent may dissolve at least some of the particles. In particular, the solvent may be anhydrous.

[0152] The hydrophobic material may be, for example, PLGA. The particles or aggregates of particles may be dried with the hydrophobic material in a 1:1 w / w ratio. The solution in which the particles or aggregates of particles are dispersed or suspended may be a solution of DCM and the hydrophobic material. In certain embodiments, a suspension of a hydrophobic material particle in a solution is dried by spray drying. The solution containing the hydrophobic material with dispersed particles or aggregates of particles may be spray dried at an outlet temperature of about 28-30°C. The solution containing the hydrophobic material with dispersed particles or aggregates of particles may be spray dried at a spray pressure of about 1 bar. The solution containing the hydrophobic material with dispersed particles or aggregates may be spray dried at a liquid supply rate of about 2 g / min.

[0153] The coated particles or aggregates of coated particles may have a particle size of less than approximately 10 μm, for example, less than approximately 9 μm, for example, less than approximately 8 μm, less than approximately 7 μm, less than approximately 6 μm, or less than approximately 5 μm. Particles or aggregates of particles may be coated by blending them with a hydrophobic material to obtain particles or aggregates coated with a layer of hydrophobic material. The hydrophobic material can be, for example, DPPC, magnesium stearate, mesoporous silica, or a combination thereof. The particles or aggregates may be blended with the hydrophobic material in a 1:1 w / w ratio. The hydrophobic material may be sieved before blending. Alternatively, the hydrophobic material may not be sieved before blending.

[0154] Particles or aggregates of particles may be blended with hydrophobic materials for a period of time of approximately 10 to 40 minutes, or approximately 15 to 30 minutes. Spray-dried nitrite particles and spray-dried proton source particles may be blended for a period of approximately 20 minutes.

[0155] aqueous environment The nitric oxide generating layer of the present invention typically releases NOx upon contact with an aqueous environment. The aqueous environment is not particularly limited. The aquatic environment may also be an aquatic biological fluid, such as bodily fluids. Such bodily fluids may include wound secretions or exudates and / or blood (plasma, serum, etc.). Alternatively, the aqueous environment may be a sterile aqueous solution. The aqueous environment may also be a Seiline solution. In some embodiments, the solid powder composition may be sufficiently hygroscopic to absorb moisture from the air, which is sufficient to initiate the release of NOx.

[0156] Examples Manufacturing of solid powder compositions Materials and analytical methods The following materials were purchased from commercially available sources: sodium nitrite from Honeywell, citric acid from Sigma Aldrich, trisodium citrate from Merck, sodium hydroxide from Fisher, PLGA RG 502H from Sigma Aldrich, mesoporous silica (Syloid 244FP) from Grace, dipalmitoylphosphatidylcholine (DPPC) from Avanti, Kollidon VA64 Fine from BASF, microcrystalline cellulose from JRS Pharma, and dichloromethane (DCM) from Sigma Aldrich. Deionized (DI) water (18.2 MΩ) was prepared using the ELGA water purification system.

[0157] Unless otherwise specified, the following analytical methods were used. Dry powder particle size distribution (PSD) by Sympatec. Laser particle size analysis of spray-dried powders was performed using a Sympatec HELOS particle size analyzer equipped with an R3 lens (range 0.5–175.0 μm) / R5 lens (range 0.5–875 μm) and an ASPIROS dispersion unit. Dispersion was performed using compressed air at a pressure of 3.00 bar and a reduced pressure of 60 bar. The powder was packed into an ASPIROS glass tube in a low-humidity environment (<25% RH) and sealed with Parafilm until measurement. Unless otherwise noted, measurements were performed three times in a row, and the average data was reported.

[0158] Example 1: A mixture containing a nitrite solution and a proton source solution is spray-dried to form a solid powder composition. The 1.5M sodium nitrite supply solution (supply solution 1) was prepared by dissolving the required amount of sodium nitrite in deionized water. The 1M citric acid supply solution (supply solution 2) adjusted to pH 4 was prepared by dissolving the required amount of citric acid in deionized water and adjusting its pH to 4 using a 10M sodium hydroxide aqueous solution. The pH of the solutions was measured using a Mettler Toledo Seven Compact pH meter.

[0159] Supply solutions 1 and 2 were subjected to spray drying using a Buchi B290 spray dryer equipped with a Buchi two-fluid nozzle. The two supply solutions were simultaneously pumped using separate supply lines (platinum-hardened silicone L / S 14 tubing) connected by a Y-connector and a single Masterflex peristaltic pump, and the supply solutions were combined immediately before spraying. A standard Buchi cyclone and collection pot were attached to collect the product.

[0160] The supply solution was spray-dried in two batches under the following conditions: [Table 1]

[0161] Next, both batches were subjected to vacuum drying for 24 hours using an Edwards Super Modulyo freeze-dryer set to 25°C. Next, particle size distribution measurements were performed on both batches using a Sympatec HELOS particle size analyzer equipped with an R3 lens (range 0.5–175.0 μm) and an ASPIROS dispersion unit. Dispersion was performed using compressed air at a pressure of 3.00 bar and a reduced pressure of 60 bar. Measurements were performed three times in a duplicated manner.

[0162] The measured particle size distribution was as follows: [Table 2] VMD = Volume-averaged grain size

[0163] Example 2: Nitrite and proton source were spray-dried separately and then blended to produce a solid composition. A 1.5M sodium nitrite solution was prepared by dissolving the required amount of sodium nitrite in deionized water. A 1M citric acid solution adjusted to pH 5.6 was prepared by dissolving the required amount of citric acid in deionized water and adjusting its pH to 5.6 using a 10M sodium hydroxide solution. The pH of the solution was measured using a Mettler Toledo Seven Compact pH meter.

[0164] These supply solutions were subjected to separate spray drying using a Buchi B290 spray dryer under the following conditions. [Table 3]

[0165] Next, all batches were subjected to vacuum drying for 24 hours using an Edwards Super Modulyo freeze-dryer set to 25°C. Next, particle size distribution measurements were performed on three batches using a Sympatec HELOS particle size analyzer equipped with an R3 lens (range 0.5-175.0 μm) and an ASPIROS dispersion unit. Dispersion was performed using compressed air at a pressure of 3.00 bar and a reduced pressure of 60 bar. The measurements were repeated three times.

[0166] [Table 4]

[0167] Next, the solid nitrite (component 2A) and the solid citric acid (pH 5.6) (component 2C) that had been spray-dried were blended using a Turbula T2F mixer at 46 rpm for 20 minutes in a ratio of 9:1 w / w of citrate solid to nitrite solid, to obtain the powder composition of Example 2.

[0168] Example 3: A solid nitrite is pulverized together with a solid proton source to produce a solid powder composition. Sodium nitrite, citric acid, and trisodium citrate were combined in the following weight proportions: 10.79%, 14.74%, and 74.47%, respectively. The mixtures were blended using a Turbula T2F mixer at 47 rpm for 10 minutes.

[0169] The blend was pulverized using an Attritor M3 fluid energy mill with a venturi pressure of 8 bar and a grinding pressure of 2 bar. The blend was fed directly into a hopper at a target feed rate of approximately 2 g / min. The resulting powder (Example 3) was collected in a single collection jar under low humidity (20% RH).

[0170] Next, particle size distribution measurements were performed using a Sympatec HELOS particle size analyzer equipped with an R3 lens (range 0.5-175.0 μm) and an ASPIROS dispersion unit. Dispersion was performed using compressed air at a pressure of 3.00 bar and a reduced pressure of 60 bar. The measurements were repeated three times.

[0171] The obtained particle size distribution measurements were as follows: [Table 5] VMD = Volume-averaged grain size

[0172] Reference Example 4: Nitrite and proton source are separately pulverized and then blended to produce a solid composition. Sodium nitrite was pulverized using an Attritor M3 fluid energy mill at a Venturi pressure of 8 bar and a grinding pressure of 2 bar. The sodium nitrite was fed directly into a hopper at a target feed rate of approximately 2 g / min. The resulting powder (compound 4A) was collected in a single collection jar under low humidity (20% RH).

[0173] Citric acid and trisodium citrate were combined in the following weight proportions: 16.51% and 83.49%, respectively. The mixture was blended using a Turbula T2F mixer at 47 rpm for 10 minutes.

[0174] The blend was pulverized using an Attritor M3 fluid energy mill with a venturi pressure of 8 bar and a grinding pressure of 2 bar. The blend was fed directly into a hopper at a target feed rate of approximately 2 g / min. The resulting powder (Example 4B) was collected in a single collection jar under low humidity (20% RH).

[0175] Next, the pulverized solid nitrite (component 4A) and the pulverized solid citric acid (component 4B) were blended in a ratio of 9:1 w / w of citrate solid to nitrite solid using a Turbula T2F mixer at 46 rpm for 20 minutes to obtain the powder composition of Reference Example 4.

[0176] NOx generation Examples 1A, 2, 3, and 4 were loaded into APTAR Unidose nasal sprays (https: / / www.aptar.com / products / pharmaceutical / uds / ) supported on a rig 30 cm above a Petri dish (9.8 mm in diameter), containing agarose along with Hanks equilibrium salt solution and pH indicator (phenol red). Figure 1 shows the pattern of powder deposition resulting from localized pH modification by the particles at the deposition sites.

[0177] Immediately after coating, the plates were transferred to a sealed chamber, and nitrogen oxides (NOx) were measured over 15 minutes by selective ion flow tube mass spectrometry (SIFT-MS). All powders, regardless of their manufacturing method, generated nitric oxide. However, differences were observed in the total amount of NOx generated among the four powders over the 15-minute period.

[0178] Agarose is buffered at a neutral to slightly alkaline pH, which should inhibit the reaction; however, it should be noted that particles can overcome this buffering effect in a short period of time and can counteract it locally. The table and Figure 2 below show the cumulative amount of NO generated in Examples 1A, 2, 3, and 4. The experimental results are normalized for the percentage of nitrite in the powder by the cumulative NO / nanomole per 1 mg of nitrite.

[0179] [Table 6]

[0180] Composition of coated solid powder Example 5: Particles coated with hydrophobic material DPPC or mesoporous silica Example 1B was blended with mesoporous silica in a 1:1 w / w ratio using a Turbula T2F mixer at 46 rpm for 20 minutes to obtain the powder composition of Example 5A.

[0181] The powder composition of Example 5B was obtained by blending DPPC with a Turbula T2F mixer at a ratio of 1:1 w / w for 20 minutes at 46 rpm.

[0182] The mixture from Example 3 was blended with mesoporous silica in a 1:1 w / w ratio using a Turbula T2F mixer at 46 rpm for 20 minutes to obtain the powder composition of Example 5C.

[0183] The mixture from Example 3 was blended with DPPC in a 1:1 w / w ratio using a Turbula T2F mixer at 46 rpm for 20 minutes to obtain the powder composition of Example 5D.

[0184] Example 6: PLGA-coated particles PLGA RG 502 H solution was prepared by dissolving PLGA (1.5 g) in DCM (approximately 30 mL), forming a clear, colorless solution. Example 1B (1.5 g) was added to this solution while stirring to form a visually uniform white suspension, supply suspension 6A in a 1:1 w / w ratio.

[0185] Similarly, a separate PLGA RG 502H solution was prepared by dissolving PLGA (1.5 g) in DCM (approximately 30 mL) to form a clear, colorless solution. Example 3 (1.5 g) was added to this solution with stirring to form feed solution 6B in a 1:1 w / w ratio as a visually uniform white suspension.

[0186] The supply suspension was subjected to spray drying using a Buchi B290 spray dryer according to the method described above. The spray drying parameters are summarized below.

[0187] [Table 7]

[0188] In a low-humidity environment (28% RH), the sample vials were placed horizontally in individual weighing boats. The lids were removed, and the openings were covered with foil (perforated with a needle). The samples were transferred to an Edwards Super Modulyo freeze-dryer set to 25°C and subjected to vacuum drying for 24 hours (the maximum observed vacuum pressure was approximately 0.1 mmbar). After vacuum drying, the samples were transferred to a low-humidity environment (approximately 24% RH) and covered with nitrogen. The vials were then sealed with Parafilm and placed in foil pouches with a desiccant for storage at 2–8°C.

[0189] Next, particle size distribution measurements were performed using a Sympatec HELOS particle size analyzer equipped with an R3 lens (range 0.5-175.0 μm) and an ASPIROS dispersion unit. Dispersion was performed using compressed air at a pressure of 3.00 bar and a reduced pressure of 60 bar. The measurements were repeated three times.

[0190] The obtained particle size distribution measurements were as follows: [Table 8] VMD = Volume-averaged grain size

[0191] Example 7: NOx generation from coated particles An aliquot (30 mg) of the powder sample was placed in a 60 mm Petri dish. A cellulose filter paper (50 mm in diameter) was placed on top of the sample and light pressure was applied. A sodium phosphate solution (10 mM, 250 μl) was dispensed onto the cellulose filter paper. The sample was immediately placed in a 650 ml chamber, which was then sealed. Humidified air was then drawn through the chamber at a rate of 650 ml / min for 30 minutes. The airflow from the outfeed was analyzed by Single Ion Flow Tube Mass Spectrometry (SIFT-MS).

[0192] [Table 9]

[0193] Production of electrospun fibers containing nitrite / acid particles Electrospun fibers incorporating particles were formed using particles containing nitrite / acid particles, which were formed by spray drying and had a particle size of <10 μm as described above (according to Example 1A).

[0194] By using methods known to those skilled in the art, powder particles containing a nitrite source and a proton source were dispersed in a solution of the polymer polycaprolactone ("PCL") or thermoplastic polyurethane ("TPU"), and the resulting mixture was subjected to electrospinning to form electrospun fibers having powder particles containing a nitrite source and a proton source, thereby producing electrospun fibers.

[0195] Example 8: Biodegradable fiber based on PCL The following examples illustrate PCL-based biodegradable fibers, including and excluding particles containing nitrite and proton sources. [Table 10]

[0196] Using microscopy techniques such as scanning electron microscopy, the particles can be observed as being dispersed within the fibers. Figure 1 shows a control sample that does not contain powder particles. Figures 2-4 show electrospun fibers in which particles containing nitrite and proton sources are present on the surface of the fiber and within the body of the fiber.

[0197] Example 9: TPU-based non-biodegradable fiber The following examples illustrate non-biodegradable fibers based on TPU: [Table 11]

[0198] Using microscopy techniques such as scanning electron microscopy, the particles can be observed as being dispersed within the fibers. Figure 5 shows a control sample that does not contain powder particles. Figures 6-8 show electrospun fibers in which particles containing nitrite and proton sources are present on the surface of the fiber and within the body of the fiber.

[0199] Example 10: Production of nitric oxide from the fibers of Example 8 The generation of nitric oxide and its precursors was evaluated using established fluorescence measurement methods. Simply put, diaminofluorescein-FM (DAF-FM), an NO sensor, is known to be converted to a fluorescent triazole in the presence of nitric oxide (and oxygen) and its precursors. The resulting triazole (DAF-T) emits light at 520 nm when excited at a wavelength of approximately 490 nm.

[0200] If necessary, the casting liner was removed from the sample prior to testing. Discs of electrospun fibers having a powder containing a nitrite source and a proton source (Examples 8B-D), and control discs without powder (Example 8A) were each placed into 5 mL polyethylene tubes having screw-type cap lids, and the weights were recorded (the discs had to be folded into four to fit into the containers).

[0201]

Table 12

[0202] An aliquot of DAF-FM (1 mM in DMSO) was diluted with deionized water to produce a 1 μM DAF-FM aqueous solution (“DAF solution”). Example 10A was charged with DAF solution (1 μM, 5 mL). Examples 10B-D were charged with DAF-FM solution (1 μM, 4 mL). The volume was set so that the electrospun discs were completely immersed in the solution. As a control, a blank sample of only DAF-FM solution was also prepared.

[0203] Initial fluorescence readings were taken for the DAF-FM solution from each sample as follows: After mixing, an aliquot of the DAF solution for each experiment was transferred separately to a clean cuvette (approx. 3 mL volume) and the fluorescence intensity was measured. The pH of the solution was also measured before returning the solution to the same individual sample vial. The samples were incubated at 30 °C between time points.

[0204] Fluorescence and pH measurements were repeated at 0, 4, 24, and 96 hours (at longer timeframes, the control showed an increasing fluorescence signal). At each time point, the vial was removed from the incubator, stirred, and thoroughly mixed to ensure complete mixing of the DAF solution. After recording any visual observations, such as the physical condition of the electrospinning disk, the required volume for the test (approximately 3 mL) was taken from the container and transferred to the same cuvette used to obtain the 0-hour sample. After recording the fluorescence measurements, pH was also measured. Using a pipette, the sample to be tested was withdrawn from the cuvette, returned to the original sample container on the same disk, and resealed with the same lid until returned to the incubator. The same method was used for all samples and controls.

[0205] The fluorescence intensity of the blank sample at each time point was subtracted from the fluorescence intensity of the test sample. The corrected intensities are shown in Figure 9. The sample containing 10% powder had the highest fluorescence intensity, followed by the sample containing 5% powder.

[0206] Biological evaluation of solid powder compositions Example 11: Evaluation of the efficacy of four formulations against Pseudomonas aeruginosa Petri dishes containing nutrient agar (NA, available from AcuMedia) were prepared and left to stand. Inoculum of Pseudomonas aeruginosa (ATCC 9027) was prepared in phosphate-buffered selenium (PBS, Sigma-Aldrich) and 1 x 10⁻⁶ 5 CFU mL -1 The sample was subjected to serial dilutions up to the final concentration. 100 mL of the inoculum was pipetteed into an NA plate, spread out, and dried at room temperature for 15 minutes. The lid was removed from the inoculated agar plate, and the open plate was placed inside an Aptar Unidose nasal spray bottle.

[0207] An Aptor delivery device containing the powder of either Example 1A, Example 3, or Reference Example 4 or Example 2 was attached to an Aptor nasal spray device, and the powder (approximately 50 mg dose) was sprayed onto an agar plate. The following table shows the examples used for each formulation.

[0208] [Table 13]

[0209] After 5 seconds, the lid of the agar plate was replaced, and the agar plate was incubated at 37°C ± 2°C for 16 hours. After incubation, the plates were photographed. For all plates, three biopsy punches were taken from a 2x2 cm area in the center of the agar plate. Bacteria were removed from each biopsy using a sterile cotton swab moistened with PBS, any cells were suspended in 10 mL of PBS, then sonicated for 5 minutes, serially diluted, and placed on NA.

[0210] A negative control plate not exposed to the sprayed powder, and a positive control plate with 1 mL of bleach added, were also tested simultaneously. All tests were repeated five times. For each test item, three replicates were randomly selected, and DNA was extracted from 400 μL per biopsy using the DN easy Blood & tissue Kit (Qiagen) according to the manufacturer's instructions. The samples were eluted in AE buffer to a final volume of 100 μL.

[0211] For each extraction, qPCR was performed three times in duplicate using the QuantiNova Pathogen and IC kit (Qiagen) according to the manufacturer's instructions. Each reaction tube contained each primer at a final concentration of 16 μM and a 5 μM labeled probe.

[0212] The cycle conditions were as follows: 10 minutes at 50°C, 2 minutes at 95°C, 5 seconds at 95°C, 30 seconds at 55°C, and 1 minute at 72°C, for a total of 35 cycles. Each assay run was validated with a positive control (Pseudomonas aeruginosa) and a negative control (RNase-free water). The data were analyzed using Q-Rex software (Qiagen), and Cq values ​​were obtained from predetermined thresholds. For each sample, the mean Cq value was calculated as 1 x 10⁻⁶. 2 ~108 ·CFU·mL -1 Compare with the standard curve within the established range of -1 , and calculate the final sample concentration in Log 10 CFU·mL -1 as calculated at -1 .

[0213] Table 1: Mean recovery rate and reduction rate of Pseudomonas aeruginosa of three biopsy punches collected from the center of new nutrient agar seeded at 1x10 5 ·CFU·mL -1 after treatment with Formulations 1, 2, 3, 4 and bleach, compared with untreated negative control (N = 5)

[0214]

Table 14

[0215] Pseudomonas aeruginosa was observed at an average recovery rate of 7.44 ± 0.17 Log 10 CFU·mL -1 from biopsies collected from the negative control plates. Pseudomonas aeruginosa was observed at an average recovery rate of 3.52 ± 3.12 and 1.36 ± 2.13 Log 10 CFU·mL -1 from biopsies collected from Formulations 2 and 3. No viable Pseudomonas aeruginosa was recovered from biopsies collected from Formulations 1 and 4 or the positive control plates.

[0216] Table 2: Molecular quantification of Pseudomonas aeruginosa in biopsy punches collected from new nutrient agar seeded at 1x10 5 ·CFU·mL -1 after treatment with Formulations 1, 2, 3, 4 and bleach, compared with untreated negative control

[0217]

Table 15

[0218] After treatment with the powders of Formulation 1 and Formulation 4, a significant decrease was observed in the recovery rate of viable Pseudomonas aeruginosa from biopsies taken from new nutrient agar seeded with 1x10 5 ·CFU·mL -1 of inoculum. No viable Pseudomonas aeruginosa was observed when compared to the untreated negative control. Molecular quantification reflects the recovery rate from colony counts.

[0219] Example 12: Cell binding and proliferation Method (As described above) Four types of PLGA non-woven fiber scaffolds containing 0, 1, 5 and 10% (wt / wt) NO generating powder were produced by electrospinning. After preliminary tests to confirm low bioburden and optimal cell loading density, discs with a diameter of 8 mm were aseptically cut from the electrospun fiber sheets received and placed in individual sterile plates. A suspension of VERO was applied to each disc at a density of 5x10 4 cells / disc. As a positive control, the same number of cells were seeded in a cell culture plate of the same size, and as a negative control, the inventors incubated the discs in cell culture plastic with only the medium (no cells). After 24 hours and 7 days, the discs were recovered, rinsed with sterile PBS to remove non-adherent cells, and then: 1. Subjected to cell lysis buffer and the cell content was evaluated by quantification of total double-stranded DNA (dsDNA), 2. Prepared for cell morphology analysis by electron microscopy.

[0220] TIFF2026512646000017.tif4381

[0221] Results Morphological evaluation of cells bound to the scaffold at 7 days in Figure 12 shows that cells bound to the PLGA matrix alone maintained their roundness and spread along the fibers was minimized (Figure 12A). In contrast, cell cultures were observed to spread along the fibers and crosslink between fibers (Figure 12B-D). Similar spreading was observed with all doses of NO-releasing powder. Incorporation of NO-releasing powder into a PLGA nonwoven fabric scaffold did not adversely affect cell binding or proliferation, and increased cell diffusion and crosslinking between fibers within the scaffold.

[0222] Example 13: Effect of a powdered composition on the sprouting of human umbilical vein endothelial cells (HUVECs) in a spheroid-based cell angiogenesis assay. 10x concentrated stock solutions / suspensions of Examples 1B and 6A were prepared in basal medium (without supplements and FCS) by vortexing and pipetting. Subsequently, semi-logarithmic dilution series were prepared in the same medium.

[0223] [Table 16]

[0224] endothelial cells Cells: HUVEC, primary human umbilical vein endothelial cells (PromoCell, Heidelberg, Germany), passages 3-4 Morphology: They adhere to each other and proliferate as single layers, like round stones. Culture medium: Endothelial cell proliferation and basal medium (ECGM / ECBM, PromoCell) Secondary culture: Divide into 1:3 groups; approximately 1x10 every 3-5 days. 4 cells / cm 2 Seed out Incubation: 37℃, 5% CO2 Doubling time: 24-48 hours Storage: Approximately 1 x 10⁶ units in 70% medium, 20% FCS, and 10% DMSO. 6 Freeze cells / ampoules Origin: Human umbilical veins from pooled donors

[0225] Test method The experiment was performed using a modified version of the initially published protocol (Korff and Augustin: J Cell Sci 112:3249-58, 1999). Briefly, spheroids were prepared by pipetting 400 HUVEC cells into a plastic dish using a hanging drop method, as described (Korff and Augustin: J Cell Biol 143:1341-52, 1998), and allowing the spheroids to aggregate overnight. Next, 50 HUVEC spheroids were seeded onto 0.9 ml of collagen gel and polymerized by pipetting into each well of a 24-well plate. After 30 minutes, the pre-incubated test samples were added by pipetting 10x working solution (100 μl) onto the polymerized gel (see Table 1 for final assay concentrations). The plates were incubated at 37°C for 24 hours and then fixed by adding 4% PFA (Roth, Karlsruhe, Germany).

[0226] quantitative The germination strength of HUVEC spheroids treated with test samples was quantified using an image analysis system that measured the cumulative germination length (CSL) per spheroid. Photographs of individual spheroids were taken using an inverted microscope and digital image software - NIS-Elements BR3.0 (Nikon). The spheroid photographs were then uploaded to the Wimasis website for image analysis. The cumulative germination length of each spheroid was measured using the WimSprout image analysis system. The average cumulative germination length of 10 randomly selected spheroids was analyzed as individual data points. The mean and standard deviation (SD) values ​​of each data point, which were repeated three times, were converted to a percentage relative to the baseline.

[0227] result Figure 13 shows the CSL for Examples 1B and 6A compared to the reference control. The effect of Example 1B (particles without coating, subjected to spray drying) is small compared to the reference control. In contrast, the PLGA-coated particles of Example 6A show a significant dose-dependent effect compared to the reference control. This indicates that the coated particles provide a local environment that enables the acidification of nitrites, even though the environment is substantially neutral.

[0228] Example 14: Dissolution of nitrite into polymer material PLGA fiber manufacturing Poly(lactic acid-coglycolic acid) (PLGA), containing lactic acid and glycolic acid in different proportions, was dissolved in dimethyl sulfoxide (DMSO). Sodium nitrite was dissolved in methanol. A slight precipitate was observed when the sodium nitrite / methanol solution was added to the DMSO-PLGA solution, but it dissolved easily upon stirring, resulting in a clear and homogeneous solution. The solids content of the PLGA polymer in DMSO changed in the initial DMSO-PLGA solution so that the final solution containing sodium nitrite and methanol was sufficiently viscous for stable electrospinning. The concentration of sodium nitrite in the resulting electrospun fibers was limited to the limit that allowed for stable electrospinning; such a concentration could be as low as 0.15% in the final fibers, but it was not limited to that.

[0229] The following examples illustrate biodegradable fibers based on PLGA containing sodium nitrite at various concentrations. [Table 17]

[0230] Figures 14A-C show scanning electron microscope images of samples A-C (Examples 14A-C).

[0231] Release of nitric oxide The generation of nitric oxide and its precursors was evaluated using established fluorescence measurement methods. Simply put, the NO sensor diaminofluorescein-FM (DAF-FM) is known to be converted to a fluorescent triazole in the presence of nitric oxide (and oxygen) and its precursors. The resulting triazole (DAF-T) emits light at 520 nm when excited at a wavelength of approximately 490 nm.

[0232] Where necessary, the casting liner was removed from the samples before testing. Discs of electrospun fibers containing sodium nitrite (Examples 14B-D) and a blank without sodium nitrite (Example 14A) were individually placed in 5 mL polyethylene tubes with screw-on caps, and their weight was recorded (the discs had to be folded into four to fit into the containers).

[0233] [Table 18]

[0234] Aliquots of DAF-FM (1 mM in DMSO) were diluted with deionized water to prepare a 1 μM DAF-FM aqueous solution ("DAF solution"). All samples were charged with the DAF solution (1 μM, 5 mL). The volume was set so that the electrospinning disk was completely immersed in the solution. For control, blank samples containing only the DAF-FM solution were also prepared.

[0235] Initial fluorescence readings were performed on the DAF solution from each sample as follows: After mixing, aliquots of the DAF solution from each experiment were transferred separately to clean cuvettes (approximately 3 mL in volume), and the fluorescence intensity was measured. The pH of the solution was also measured before returning it to the same individual sample vial. The samples were incubated at 30°C between intervals.

[0236] Fluorescence and pH measurements were repeated at 0, 24, 48, and 120 hours. At each time point, the vial was removed from the incubator, stirred, and thoroughly mixed to ensure complete mixing of the DAF solution. After recording any visual observations, such as the physical state of the electrospinning disk, the required volume for the test (approximately 3 mL) was taken from the container and transferred to the same cuvette used to obtain the 0-hour sample. After recording the fluorescence measurement, pH was also measured. Using a pipette, the sample to be tested was withdrawn from the cuvette, returned to the original sample container on the same disk, and resealed with the same lid until returned to the incubator. The same method was used for all samples and controls.

[0237] The pH of the sample is shown in Figure 15A. As the PLGA fibers were hydrolyzed, the pH decreased. It is known that the fluorescence intensity derived from diaminofluorescein-type compounds decreases with increasing acidity [Angew. Chem. Int. Ed. 1999, 38, No. 21]. To account for the loss of fluorescence intensity due to the decrease in pH during the experiment, the intensity results were proportionally adjusted using the data and sample pH shown in the reference [Angew. Chem. Int. Ed. 1999, 38, No. 21], thus normalizing all results with respect to pH and making them directly comparable to one another.

[0238] Furthermore, the fluorescence intensity of a control sample containing no PLGA material was subtracted from the fluorescence intensity of the test sample at each time point. The corrected intensity profiles are shown in Figure 15B. The results show a fluorescence signal, particularly in samples containing 0.15% sodium nitrite, indicating that the material generates nitric oxide and its precursors.

Claims

1. An implantable medical device comprising a polymer material that generates nitric oxide, wherein (i) A polymer material that generates nitric oxide comprises a polymer and (a) particles (wherein one or more individual particles each containing a nitrite and a proton source); or (b) aggregates of particles (wherein the aggregates each comprises one or more individual particles containing a nitrite, one or more individual particles containing a proton source, and may contain a binder, and / or the aggregates of particles each comprises one or more individual particles each containing a nitrite and a proton source, and may contain a binder); (ii) The polymer material that produces nitric oxide contains a polymer that is a proton source, and the polymer material that produces nitric oxide contains a nitrite dissolved in the polymer matrix that is a proton source; or (iii) The combination of (i) and (ii) described above, Implantable medical device.

2. The implantable medical device according to claim 1, wherein the water content of the polymer material that generates nitric oxide before implantation is 10% or less, 5% or less, 2% or less, or 1% or less, or the polymer material that generates nitric oxide is substantially water-free.

3. The implantable medical device according to claim 1 or 2, wherein the polymer material that generates nitric oxide forms a scaffold of the implantable medical device, or the polymer material that generates nitric oxide forms a coating on another component of the implantable medical device, or the polymer material that generates nitric oxide forms part of the fabric of the implantable medical device.

4. The implantable medical device according to any one of claims 1 to 3, wherein the polymer material that generates nitric oxide is a fiber or a coating material.

5. An implantable medical device according to any one of claims 1 to 4, wherein one or more individual particles or aggregates of particles are blended or coated with an excipient that affects the rate of water penetration into the particles, and / or an excipient that affects the rate of nitric oxide formation from the particles.

6. The implantable medical device according to claim 5, wherein the excipient that affects the rate of penetration into water particles is a hydrophobic material such as a polyol, phospholipid, magnesium stearate, or colloidal silica, and / or the excipient that affects the rate of penetration into water particles is a material that sequesters nitric oxide or a precursor of nitric oxide, such as a thiol, alcohol, amine, or amide.

7. The implantable medical device according to any one of claims 5 or 6, wherein particles containing both a nitrite and a proton source are formed by spray-drying a mixture containing a nitrite solution and a proton source solution.

8. The implantable medical device according to any one of claims 1 to 7, wherein the proton source polymer is an acidic polymer, a photoacid polymer, or a polymer of an acid precursor such as a hydrolyzable ester.

9. An implantable medical device according to any one of claims 5 to 8, wherein one or more particles or aggregates of particles are embedded in or partially embedded within the polymer of a polymer material that generates nitric oxide, or one or more particles or aggregates of particles are attached to the surface of the polymer of a polymer material that generates nitric oxide.

10. The implantable medical device according to claim 1, wherein in any (ii), the nitrite is essentially homogeneously mixed with the polymer matrix of the proton source.

11. The implantable medical device according to claim 10, wherein the polymer material that generates nitric oxide is formed from a non-aqueous solution of a nitrite and a proton source polymer.

12. An implantable medical device according to any one of claims 1 to 11, wherein the polymer of the polymer material that generates nitric oxide is a biocompatible polymer, and the polymer of the polymer material that generates nitric oxide may be absorbable.

13. The implantable medical device according to any one of claims 1 to 12, wherein the implantable medical device comprises one or more further drying components adjacent to a polymer material that generates nitric oxide.

14. An implantable medical device according to any one of claims 1 to 13, further comprising one or more further components adjacent to a polymer material that generates nitric oxide, wherein the water content of any component adjacent to the polymer material that generates nitric oxide is 10% or less, 5% or less, 2% or less, or 1% or less, based on the weight of the component adjacent to the polymer material that generates nitric oxide.

15. An implantable medical device according to any one of claims 1 to 14, wherein the implantable medical device contains an antimicrobial agent.

16. The implantable medical device according to any one of claims 1 to 15, wherein the implantable medical device is a medical device consisting of one component.

17. An implantable medical device according to any one of claims 1 to 16, wherein a polymer material that generates nitric oxide is located on the outer surface of the implantable medical device.

18. A packaged implantable medical device comprising an implantable medical device according to any one of claims 1 to 17 within a low-moisture-permeability package.

19. Low moisture permeability packaging, (i) The packaging wall contains one or more low-permeability materials (e.g., aluminum foil); (ii) sealed or (iii) Includes a pack insert that isolates moisture, The implantable medical device according to claim 18.

20. Particles or aggregates of particles for use in implanting an implantable medical device according to any one of claims 1 to 19, wherein (a) one or more individual particles each contain a nitrite and a proton source; or (b) the aggregate comprises one or more individual particles containing a nitrite, one or more individual particles containing a proton source, and may contain a binder, and / or the aggregates of particles comprises one or more individual particles each containing a nitrite and a proton source, and may contain a binder, wherein the implantable medical device is a single-member implantable medical device.

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