Optical fiber device based on temperature-sensitive hydrogel, preparation method and application

Abstract

The invention provides an optical fiber device based on temperature-sensitive hydrogel, a preparation method and application. The device comprises a flexible conduit used for injecting a photothermal conversion agent and a polymer optical fiber used for transmitting near-infrared second-area laser. The photothermal conversion agent is temperature-sensitive hydrogel and is prepared from a non-ionic surface active agent polyhydric alcohol and a nano material BL NPs; wherein the nanometer material BL NPs is prepared from a non-ionic surface active agent polyhydric alcohol and an organic molecule SW8. The optical fiber device based on the temperature-sensitive hydrogel can be used for photothermal therapy. After the polymer optical fiber with the strong scattering spherical end is adopted to transmit laser and irradiates the photothermal conversion agent BLat-F127, cell death can be effectively induced through the heat effect, the good tumor inhibition effect is achieved within a short time, and it is guaranteed that the curative effect of photothermal treatment is good.

Description

Technical Field

[0001] The present invention belongs to the technical field of photothermal therapy, and relates to a photothermal conversion agent and an optical fiber device, and specifically to an optical fiber device based on a temperature-sensitive hydrogel, a preparation method and an application thereof. Background Art

[0002] Photothermal therapy (PTT), an emerging weapon for precisely combating tumors, focuses on converting efficiently absorbed light energy into localized heat energy, achieving thermal ablation of cancer cells. Currently, the clinical application of PTT in combating tumors and other diseases faces the following challenges:

[0003] First, the biocompatibility of photothermal converters is poor: the biocompatibility of photothermal converters (PTAs) currently widely used in preclinical studies is far from ideal. Some inorganic nanomaterials (such as gold nanorods, copper sulfide nanoparticles) or their degradation metabolites in the body may trigger the immune system, activate innate or adaptive immune responses, and trigger unexpected systemic inflammatory responses or excessive immune stress. This uncontrolled immune activation not only directly threatens the safety of treatment, but may also disrupt the delicate balance of the tumor microenvironment. On the one hand, the inflammatory cytokine storm may damage normal tissues; on the other hand, sustained immune pressure may lead to the emergence of more aggressive tumor cell subpopulations, accelerate their immune escape process, and ultimately offset the foundation of PTT's efficacy.

[0004] Second, the active targeting ability of photothermal converters is insufficient: after intravenous injection of photothermal converters, a large amount of nanomaterials are easily captured and cleared by the mononuclear phagocytic system of the liver, spleen, etc. (RES effect), and the amount of drugs that actually reach and remain in the tumor site is limited. Passive targeting (such as the EPR effect) is inefficient and has huge individual differences. This "inaccurate ammunition delivery" results in the need to increase the systemic administration dose in order to reach the therapeutic threshold, which in turn exacerbates the aforementioned biocompatibility risks and forms a vicious cycle. At the same time, off-target accumulation may also cause potential photothermal damage to normal organs (such as the liver and kidneys).

[0005] Third, the penetration depth of laser light sources is limited: Near-infrared II (NIR-II, 1000-1700nm) light, with its significantly superior tissue penetration and higher maximum permissible exposure (MPE) compared to the traditional NIR-I window, has become a promising light for ablation of deep-seated solid tumors. However, when faced with tumor lesions buried deep within organ parenchyma or encased in thick tissue, the penetration of NIR-II light is still insufficient, and the energy is significantly attenuated before reaching the target. To overcome this limitation, interventional fiber-optic light delivery has become a practical option. Although the emission angle of traditional blunt-end optical fibers is narrow, their single-point coverage is extremely limited. Summary of the Invention

[0006] In view of the defects and shortcomings of the existing technology, the purpose of the present invention is to provide an optical fiber device based on temperature-sensitive hydrogel, a preparation method and application, so as to solve the technical problems of poor biocompatibility and insufficient active targeting ability of photothermal conversion agents in photothermal therapy in the existing technology, as well as the limited penetration depth of laser light sources.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A temperature-sensitive hydrogel-based optical fiber device comprises a flexible catheter for injecting a photothermal conversion agent and a polymer optical fiber for transmitting near-infrared zone II laser.

[0009] The photothermal conversion agent is a temperature-sensitive hydrogel, which is made of a non-ionic surfactant polyol and a nanomaterial BL NPs; wherein the nanomaterial BL NPs is made of a non-ionic surfactant polyol and an organic molecule SW8.

[0010] The present invention also has the following technical features:

[0011] Specifically, the mass ratio of the nonionic surfactant polyol to the nanomaterial BL NPs is 176-183:1; the mass ratio of the nonionic surfactant polyol to the organic molecule SW8 used to prepare the nanomaterial BL NPs is 10:1.

[0012] Specifically, the nonionic surfactant polyol is Pluronic F-127.

[0013] Specifically, the polymer optical fiber is made of polylactic acid, and the number average molecular weight of the polylactic acid is 80,000.

[0014] Specifically, the end of the polymer optical fiber is a spherical structure.

[0015] Specifically, the diameter of the end of the polymer optical fiber is 600 μm, and the diameter of the optical fiber excluding the end is 480-520 μm.

[0016] Specifically, the wavelength range of the near-infrared second zone laser is 1000-1700 nm, preferably 1064 nm.

[0017] The present invention also protects a method for preparing an optical fiber device based on the temperature-sensitive hydrogel as described above, characterized in that the method includes preparing a temperature-sensitive hydrogel, specifically comprising: dissolving a non-ionic surfactant polyol and nanomaterial BL NPs at 4°C to prepare a hydrogel solution, and then standing it at 38°C for at least 150 seconds to obtain a solidified temperature-sensitive hydrogel.

[0018] Specifically, the method includes the following steps:

[0019] Step 1: Preparation of temperature-sensitive hydrogel:

[0020] Step 1.1, preparation of nanomaterials BL NPs:

[0021] SW8 was dissolved in tetrahydrofuran, and then Pluronic F-127 was dissolved in deionized water. The tetrahydrofuran solution of SW8 was then gradually added to the Pluronic F-127 aqueous solution. After ultrasonic treatment for 5 minutes, the mixture was stirred for 12 hours and the tetrahydrofuran was removed by nitrogen purge. The reaction solution was filtered, and the sample collected by filtration was concentrated to obtain the nanomaterial BL NPs.

[0022] Step 1.2, preparation of hydrogel:

[0023] Pluronic F-127 powder was dispersed into a solution of nanomaterial BL NPs and stirred at 4°C. Pluronic F-127 was added again during the stirring process until the powder was completely dissolved, obtaining a hydrogel solution with a total mass fraction of Pluronic F-127 of 15 wt%. The solution was then placed in a 4°C refrigerator for 24 hours and then allowed to stand at 38°C for at least 150 seconds to obtain a solidified temperature-sensitive hydrogel BL@F127.

[0024] Step 2: Prepare polymer optical fiber using thermal stretching method:

[0025] Step 2.1, preparation of polymer optical fiber:

[0026] PLA particles were placed in a reaction vessel and heated at 220°C for 10 minutes to melt the PLA particles. A quartz optical fiber with a diameter of 700±20 μm and a length of 5 cm was then used as a medium. The end (2 mm) of the quartz optical fiber was immersed in the molten PLA so that its surface was coated with a layer of PLA. Subsequently, the quartz optical fiber was pulled upward at a uniform speed of 25 cm / min. The stretched molten PLA formed a polymer optical fiber with a diameter of 500±20 μm after cooling.

[0027] Polylactic acid particles were dissolved in dichloromethane to obtain a polylactic acid solution with a mass concentration of 6%; a polymer optical fiber was immersed in the polylactic acid solution for 5 seconds and then ventilated in a fume hood for 1 minute; after repeating three times, the dichloromethane was completely evaporated, a nanopore was formed at the end of the polymer optical fiber, and a polymer optical fiber with a strongly scattering spherical end with a diameter of 600 μm was obtained.

[0028] Step 3: Prepare micro devices:

[0029] Step 3.1, in situ injection of photothermal conversion agent:

[0030] 25 μL of photothermal conversion agent BL@F127 with a mass fraction of 0.8 mg / mL was injected in situ through a flexible catheter, which was assisted by a puncture needle outside; the diameter of the puncture needle was 900 μm, and the diameter of the flexible catheter was 100 μm.

[0031] Step 3.1, bonding the flexible catheter and the optical fiber:

[0032] The polydimethylsiloxane system mixture was prepared in advance, and then a length of 0.5 cm and an inner diameter of 1.5 mm of a hose was cut as a mold, the optical fiber and the flexible catheter were placed in the mold in a staggered manner, so that the distance between the tips of the flexible catheter and the optical fiber was 1 mm; then 5 mL of the polydimethylsiloxane system mixture was used to completely fill the gap between the optical fiber and the flexible catheter, and then placed in a 60℃ oven overnight, and after solidification, the mold was demolded with a blade.

[0033] The application also protects the use of the temperature-sensitive hydrogel-based optical fiber device as described above in photothermal therapy.

[0034] Compared with the prior art, the application has the following beneficial technical effects:

[0035] (I) The temperature-sensitive hydrogel BL@F127 of the application has good biocompatibility. At the same time, since the temperature-sensitive hydrogel exhibits excellent fluidity, it has good active targeting ability as a photothermal conversion agent, and can be directly injected into the tumor site or the surrounding area. These hydrogels will quickly phase change from liquid to gel under body temperature induction, thereby forming a high-concentration drug pool at the tumor site, prolonging the drug accumulation time.

[0036] The polymer optical fiber prepared by the application has a low loss rate after bending, can adapt to complex biological environments, has good light guiding properties in biological tissues, can effectively deliver light energy to deep tissues, has a small light transmission energy loss, and the polymer optical fiber with a strong scattering spherical end can achieve uniform excitation on a larger spherical area.

[0037] After the polymer optical fiber with a strong scattering spherical end is used to deliver laser and irradiate the photothermal conversion agent BL@F127, the heat effect can effectively induce cell death, achieving good tumor inhibition effect in a short time, and ensuring good curative effect of photothermal therapy.

[0038] (II) In addition to good biocompatibility and active targeting ability, the temperature-sensitive hydrogel (BL@F127) of the application has high photothermal conversion efficiency, good morphological stability, excellent thermal stability and good photothermal performance, and is an ideal photothermal conversion agent. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1Schematic diagram of the structure of optical fiber devices based on temperature-sensitive hydrogels. Figure 1 Middle: 1-puncture needle, 2-polymer optical fiber, 3-flexible catheter, 4-strong scattering spherical tip.

[0040] Figure 2 Characterization of polymer optical fibers. Figure 2 Middle: (a) shows a physical image of three optical fibers; (b) shows the transmission loss of a polymer optical fiber in chicken tissue as a function of length; (c) shows the transmission loss of a polymer optical fiber in air as a function of length; (d) shows the relationship between the degree of bending and the bending loss of a polymer optical fiber. (e) shows the actual light-guiding properties of a polymer optical fiber inserted into different media (air and chicken tissue). (f) shows the divergence characteristics of the output light from the three optical fibers. (g) is a quantified image of (f). (h) shows the microscopic morphology of a polymer optical fiber with a strongly scattering spherical end. (i) HE staining of the surrounding tissue after the three optical fibers were implanted subcutaneously in mice for 7 days. "F" indicates the region where the optical fiber is located. Scale bar: 100 μm.

[0041] Figure 3 The characterization and photophysical properties of the photothermal conversion agent BL@F127 are demonstrated. Figure 3 Middle: (a) shows the morphology and size of BL@F127; (b) shows the normalized absorption spectrum (blue region) and fluorescence spectrum (red curve) of the photothermal converter BL@F127 in water; (c) shows the photothermal conversion efficiency curve of the photothermal converter BL@F127; (d) shows the particle size stability of the photothermal converter BL@F127 over 10 days; (e) shows the thermal stability of the photothermal converter BL@F127 under 1064nm laser irradiation; (f) shows the concentration dependence of the photothermal performance of the photothermal converter BL@F127; (g) shows the photothermal images of BL@F127 and water under laser irradiation of different powers; (h) shows the laser power dependence of the photothermal performance of BL@F127.

[0042] Figure 4 The results of in vitro cell experiments on the photothermal conversion agent BL@F127 combined with optical fiber are shown. Figure 4 Middle: (a) NIR-II fluorescence image of HeLa cells co-incubated with the photothermal converter BL@F127 for 30 minutes. (b) Cell viability at different concentrations of the photothermal converter BL@F127. (c) Cell fluorescence imaging of the PBS group, the PBS group irradiated with a quartz fiber laser, the BL@F127 group, and the BL@F127 group irradiated with three types of fiber lasers. Green indicates live cells and red indicates dead cells. (d) Flow cytometry results of the PBS group, the PBS group irradiated with a quartz fiber laser, the BL@F127 group, and the BL@F127 group irradiated with three types of fiber lasers. (e) Quantification of (d).

[0043] Figure 5 The results of in vitro characterization experiments of three optical fibers and temperature field distribution simulation of combined photothermal conversion agents are presented. Figure 5 Middle: (a) Demonstrates the energy transmission characteristics of a needle-assisted optical fiber using four different devices. From left to right, they are: an external needle-assisted optical fiber passing through a porous polymer plate; an external needle-assisted optical fiber passing through pork tissue and a porous polymer plate; a single optical fiber passing through pork tissue and a porous polymer plate; and a conventional laser beam passing through pig tissue and a porous polymer plate. (b) Shows the optical power values ​​recorded below the polymer plate for each of the four devices. (c) A line graph of the optical energy transmitted through different pork thicknesses for the three optical fibers. (d) A physical image of the light transmission experimental platform for (c) and (e). (e) A line graph of the temperature inside the plastic tube for the three optical fibers passing through different pork thicknesses. (f) Demonstrates the thermal conduction of the optical hotspot detected using a temperature measurement device. (g) and (h) Show the three-dimensional steady-state thermal conduction results from a computer-simulated tumor model. (i) Shows the heating area of ​​the three optical fibers.

[0044] Figure 6 Fluorescence imaging and in vivo photothermal properties of tumor tissue were demonstrated. Figure 6 Middle: (a) shows the enrichment of the photothermal converter BL@F127 in mouse subcutaneous tumors; (b) is the NIR-II fluorescence image of the photothermal converter BL@F127 in mice; (c) shows the change of the NIR-II fluorescence signal of the photothermal converter BL@F127 as the tumor grows; (d) shows the photothermal treatment effect of the photothermal converter BL@F127 on mice with HeLa subcutaneous tumors in vivo.

[0045] Figure 7 In vivo animal experiment results of the photothermal converter BL@F127 combined with three optical fibers. (a) Shows the results of treating tumors in tumor-bearing mice by covering the tumor sites with pork to simulate real deep-seated tumors. (b) Graphs of in vivo photothermal temperature increases in five groups of mice after photothermal treatment; (c) Tumor volume growth curves in five groups of mice after photothermal treatment. (e) Shows the tumor weights of the five groups of mice after treatment. (d) Shows the tumors of mice treated with the photothermal converter and polymer optical fiber. (f) HE and TUNEL staining results of tumor tissues in the five groups of mice after treatment. (g) Western blot analysis of classical apoptosis- and pyroptosis-related proteins; (h) Western blot quantification of apoptosis-related proteins (Bax, Bcl2, Cleaved-Caspase 3, and Cleaved-PARP1); (i) Western blot quantification of pyroptosis-related proteins (Cleaved-Caspase 1 and Cleaved-Gasdermin D). The technical solution of the present invention is further described below in conjunction with embodiments.

[0046] The technical solution of the present invention is further described below in conjunction with embodiments. DETAILED DESCRIPTION

[0047] It should be noted that the raw materials used in the present invention, unless otherwise specified, are conventional raw materials known in the prior art. For example, SW8 is an organic molecule known in the prior art, described in the document "Acceptor Engineering Produces Ultrafast Nonradiative Decay in NIR-II Aza-BODIPY Nanoparticles for Efficient Osteosarcoma Photothermal Therapy via Concurrent Apoptosis and Pyroptosis" published in 2023.

[0048] In accordance with the above technical solution, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0049] Example 1:

[0050] This example provides an injectable temperature-sensitive hydrogel BL@F127, which is made of the nonionic surfactant polyol Pluronic F-127 and the nanomaterial BL NPs, with a mass ratio of 176:1. The BL NPs are made of Pluronic F-127 and the organic molecule SW8, with a mass ratio of 10:1.

[0051] Example 2:

[0052] This example provides a method for preparing the injectable temperature-sensitive hydrogel BL@F127 of Example 1, which specifically includes the following steps:

[0053] Step 1.1, preparation of nanomaterials BL NPs:

[0054] 1 mg of SW8 was dissolved in 1 mL of tetrahydrofuran, and then 10 mg of Pluronic F-127 was dissolved in 10 mL of deionized water; then the tetrahydrofuran solution of SW8 was gradually added to the sample bottle in which the Pluronic F-127 aqueous solution was dissolved, and ultrasonic treatment was performed for 5 minutes; the sample bottle was placed on a magnetic stirrer for stirring for 12 hours, and tetrahydrofuran was removed by nitrogen blowing; the solution was filtered by using a 0.45 μm aqueous filter membrane, and the collected sample solution was concentrated to 1 mg / mL by using an ultrafiltration centrifuge tube for storage, to obtain nanomaterials BL NPs.

[0055] Step 1.2, preparation of hydrogel:

[0056] Pluronic F-127 powder was gradually dispersed into the solution of nanomaterials BL NPs, 176 mg of Pluronic F-127 was added into 1 mL of BL NPs solution with a concentration of 1 mg / mL under magnetic stirring at 4°C until the powder was completely dissolved, i.e. a hydrogel solution with a total mass fraction of Pluronic F-127 of 15 wt% in BL@F127 was prepared, and then it was placed in a 4°C refrigerator for 24 hours to remove air bubbles; after standing at 38°C for at least 150 s, a temperature-sensitive hydrogel BL@F127 with a solidified shape was obtained; after gel formation, the sample was visually recorded by photography.

[0057] Example 3:

[0058] This example gives a near-infrared two-zone optical fiber device based on temperature-sensitive hydrogel, which comprises a puncture needle (1), a polymer optical fiber (2) and a flexible catheter (3) fixed in the puncture needle (1), the end of the polymer optical fiber (2) is a strongly scattering spherical end (4), and the polymer optical fiber (2) is used for transmitting 1064 nm NIR II laser; the flexible catheter (3) is used for delivering a light-heat conversion agent, and the light-heat conversion agent is the temperature-sensitive hydrogel BL@F127 of Example 1.

[0059] As a specific scheme of this example, the polymer optical fiber (2) and the flexible catheter (3) in the puncture needle (1) are fixed by using a polydimethylsiloxane system (Dow Corning DC184). The polydimethylsiloxane system is a conventional adhesive known in the prior art, which is purchased from Dow Corning DC184 PDMS company, and is uniformly mixed by using a main agent (main components are vinyl-containing polydimethylsiloxane and may also contain fillers such as silica, plasticizers, etc.) and a curing agent (main functional components are hydrogen-containing silicone oil and platinum catalyst) at a weight ratio of 10:1.

[0060] As a specific scheme of this example, the diameter of the flexible catheter (3) is 100 μm.

[0061] As a specific and preferred solution of this embodiment, the diameter of the strongly scattering spherical end (4) of the polymer optical fiber (2) is 600 μm, and the diameter of the polymer optical fiber excluding the end is 500±20 μm.

[0062] As a specific and optional solution of this embodiment, a quartz optical fiber or a flat-end polymer optical fiber may also be used; the diameters of the quartz optical fiber and the flat-end polymer optical fiber are both 500±20 μm.

[0063] Example 4:

[0064] This embodiment provides a method for preparing a near-infrared second-zone optical fiber device based on a temperature-sensitive hydrogel according to embodiment 3. The method specifically comprises the following steps:

[0065] Step 1: Preparation of temperature-sensitive hydrogel: The specific process is the same as in Example 2 above.

[0066] Step 2: Prepare polymer optical fiber using thermal stretching method:

[0067] Step 2.1, preparation of polymer optical fiber:

[0068] Polylactic acid (PLA) pellets were placed in a 5mL beaker and heated to 220°C using an electric heater. The PLA pellets melted after 10 minutes of heating. A quartz optical fiber with a diameter of 700±20μm and a length of approximately 5cm was used as the medium. The end of the quartz fiber (approximately 2mm) was immersed in the molten PLA, coating the surface with a layer of PLA. The quartz fiber was then pulled upward by a stepper motor at a uniform speed of ~25cm / min to control the diameter of the resulting polymer fiber. During the upward pulling process, the polymer fiber was pulled out from the end of the quartz fiber. After the stretched molten PLA cooled to room temperature, a polymer fiber with a diameter of approximately 500±20μm was formed.

[0069] In this embodiment, the quartz optical fiber is a commercial optical fiber purchased from Rayward Corporation.

[0070] Step 2.2, preparation of flat-ended polymer optical fiber (FPQF) and strongly scattering spherical-ended polymer optical fiber (SPQF):

[0071] The prepared polymer optical fiber was cut off for subsequent experiments. Subsequently, a polymer optical fiber with a flat end and a strongly scattering spherical end was prepared. Among them, the flat end was directly cut with a heated optical fiber cutter. The preparation method of the strongly scattering spherical end is as follows: polylactic acid particles are dissolved in dichloromethane to obtain a polylactic acid solution with a mass concentration of 6%. The polymer optical fiber is immersed in the polylactic acid solution for 5 seconds and then ventilated in a fume hood for 1 minute. After repeating three times, once the dichloromethane is completely volatilized and a nanopore is formed at the end of the polymer optical fiber, a strongly scattering spherical end is obtained. The diameter of the strongly scattering spherical end is measured by CCD imaging and is about 600μm.

[0072] Step 3: Prepare micro devices:

[0073] Step 3.1, in situ injection of photothermal conversion agent:

[0074] The photothermal conversion agent BL@F127 (25 μL, 0.8 mg / mL) was injected in situ through a flexible catheter, assisted by an external puncture needle with a diameter of 900 μm.

[0075] Step 3.1, bonding the flexible conduit and optical fiber:

[0076] Prepare the polydimethylsiloxane system in advance, then cut a hose with a length of 0.5 cm and an inner diameter of 1.5 mm as a mold. Place the optical fiber and flexible catheter in the mold with an offset position so that the distance between the flexible catheter and the tip of the optical fiber is 1 mm. Then use a 5mL syringe to completely fill the gap between the optical fiber and the flexible catheter with the polydimethylsiloxane system mixture. Then place it in a 60°C oven overnight. After curing, use a blade to demold it.

[0077] Example 5:

[0078] This example provides an injectable, temperature-sensitive hydrogel, BL@F127, made from the nonionic surfactant polyol Pluronic F-127 and the nanomaterial BL NPs, with a mass ratio of 183:1. The hydrogel in this example performs similarly to that in Example 1, demonstrating that excellent results can be achieved even when the total mass fraction of Pluronic F-127 exceeds the critical mass fraction for hydrogel formation.

[0079] Comparative Example 1:

[0080] This comparative example provides a method for preparing the injectable, temperature-sensitive hydrogel BL@F127 described in Example 1. This method is essentially the same as that in Example 2, except that the mass ratio of the nonionic surfactant polyol Pluronic F-127 to the nanomaterial BL NPs is 170:1. This comparative example failed to produce a hydrogel because the total mass fraction of Pluronic F-127 was below the critical mass fraction for hydrogel formation.

[0081] Comparative Example 2:

[0082] This comparative example provides a method for preparing the injectable temperature-sensitive hydrogel BL@F127 of Example 1. This method is essentially the same as that of Example 2, except that the heating temperature is set to 37°C. This comparative example failed to successfully produce a hydrogel because the temperature was too low to reach the solution-gel transition temperature.

[0083] Effect verification:

[0084] (A) Characterization of quartz optical fiber (QOF), flat-ended polymer optical fiber (FPOF), and strongly scattering spherical-ended polymer optical fiber (SPOF):

[0085] from Figure 2 In (a), we can see the macroscopic morphology of the three optical fibers. Figure 2 The spherical end design of the strongly scattering spherical-end polymer optical fiber can be clearly seen in (h).

[0086] from Figure 2 As can be seen in (b), the transmission loss of the polymer optical fiber in the chicken tissue is 0.479db / cm. Figure 2 As can be seen from (c), the transmission loss of polymer optical fiber in air is 0.159db / cm. Figure 2 As can be seen in (d), the polymer optical fiber is bent into a circle with a radius of 1 cm without breaking, and the bending loss is only about 24%, indicating that it can adapt to complex biological environments.

[0087] from Figure 2 As can be seen in (f), the actual light-guiding properties of polymer optical fibers when inserted into different media (air and chicken tissue): when the optical fiber is inserted into chicken tissue, scattering occurs at the insertion site due to the change in the refractive index between air and biological tissue; the refractive index of the middle part does not change, so there is no transverse scattered light; there is obvious light output at the light-emitting end, verifying its good light-guiding properties in biological tissue. In order to further verify the divergence characteristics of the optical fiber output light, quartz optical fiber, flat-end polymer optical fiber, and strongly scattering spherical-end polymer optical fiber were passed through the laser, and the spot distribution emitted by the three optical fibers was recorded and compared. The results are shown in Figure 1. Figure 2(g) and (h). Figure 2 As can be seen in (g), the light emitted by the quartz fiber or the flat-end polymer fiber can only illuminate a small angle range in front, while the polymer fiber with a spherical end can achieve uniform excitation over a larger spherical area; Figure 2 As can be seen in (h), the light spot intensity of the strongly scattering spherical end polymer optical fiber is the strongest.

[0088] After the three optical fibers were implanted into the mice subcutaneously for 7 days, the surrounding tissues were stained with HE. Figure 2 (i) As shown. Figure 2 (i) It can be seen that the inflammatory response around the flat-end polymer fiber and the strongly scattering spherical-end polymer fiber is mild, which proves that the in vivo biocompatibility of the flat-end polymer fiber and the strongly scattering spherical-end polymer fiber is better than that of the quartz fiber (F' represents the area where the fiber is located).

[0089] (B) Characterization and photophysical properties of the photothermal conversion agent BL@F127:

[0090] from Figure 3 As can be seen in (a), the particle size of the nanoparticles of the photothermal conversion agent BL@F127 is about 100 nm, and the morphology is relatively uniform; Figure 3 As can be seen in (b), the photothermal conversion agent BL@F127 has two absorption peaks at 745nm and 986nm. In addition, under the excitation of 1064nm, the emission wavelength of the photothermal conversion agent BL@F127 is between 1000nm and 1300nm, with the highest emission peak at 1134nm. Figure 3 (c) It can be seen that the photothermal conversion efficiency of the photothermal conversion agent BL@F127 is 74% (excitation wavelength is 1064nm, power is 0.23W). Figure 3 (d) It can be seen that the particle size of the photothermal conversion agent BL@F127 remains unchanged at 4°C within 14 days, proving its good stability. Figure 3 (e) It can be seen that the maximum temperature rise of the photothermal conversion agent BL@F127 remains basically unchanged after 5 on / off cycles of 1064nm laser irradiation at 0.20mg / mL and 0.23W, indicating good thermal stability. Figure 3 (f) It can be seen that under 1064nm laser irradiation of 0.15~0.25W, the temperature change curve of 0.20mg / mL photothermal conversion agent BL@F127 shows a gentle trend over time, indicating that the photothermal conversion agent BL@F127 has excellent photothermal performance. Figure 3 (g) It can be seen that under 1064nm laser irradiation of 0.15~0.25W, the photothermal conversion agent BL@F127 exhibits excellent photothermal performance. Figure 3(h) It can be seen that under the irradiation of 0.23 W 1064 nm laser, the temperature-time curve of the photothermal conversion agent BL@F127 at 0.05-0.25 mg / mL shows a gentle trend, indicating that the photothermal conversion agent BL@F127 has excellent photothermal performance.

[0091] (C) In vitro cell experiment results of the photothermal conversion agent BL@F127 combined with three optical fibers:

[0092] From Figure 4 (a) it can be seen that after co-incubating the photothermal conversion agent BL@F127 and HeLa cells for 30 minutes, obvious NIR-II fluorescence can be observed under laser irradiation, indicating that HeLa cells can effectively uptake the photothermal conversion agent BL@F127. From Figure 4 (b) it can be seen that in the dark environment, even at a high concentration of the photothermal conversion agent, the cell viability is more than 80%, indicating that the photothermal conversion agent BL@F127 has good biocompatibility and safety. However, after laser irradiation for 5 minutes, the cell survival rate of HeLa cells is reduced to more than 80% when the concentration of the photothermal conversion agent BL@F127 is 50 μg / mL and 100 μg / mL, indicating that after laser irradiation of the photothermal conversion agent BL@F127, cell death can be effectively induced by thermal effect. From Figure 4 (c) it can be seen that the number of living cells (green fluorescence) in the PBS group, the quartz optical fiber laser irradiation PBS group and the BL@F127 group is large, while the number of dead cells (red fluorescence) is large after the three optical fiber laser irradiation of BL@F127.

[0093] Further, the apoptosis of Hela cells was detected by flow cytometry, and the results are shown in Figure 4 (d) and (e). From Figure 4 (d) it can be seen that compared with the control group, the percentage of apoptotic cells of the photothermal conversion agent BL@F127 irradiated by the three groups of optical fibers is significantly increased, among which the strong scattering spherical end polymer optical fiber induces the highest proportion of HeLa cell apoptosis, indicating that the combination of the strong scattering spherical end polymer optical fiber and the photothermal conversion agent BL@F127 has stronger cell killing ability. From Figure 4 (e) it can be seen that there is a significant difference between the strong scattering spherical end polymer optical fiber group and the quartz optical fiber laser irradiation photothermal conversion agent BL@F127 group (*P<0.05).

[0094] (D) In vitro characterization test of three optical fibers and temperature field distribution simulation combined with photothermal conversion agent:

[0095] Four devices were used to compare the energy transmission characteristics of optical fibers with and without puncture needle assistance, as shown in Figure 5As shown in (a), from left to right, they are: external puncture needle-assisted optical fiber passing through a porous polymer plate (Setup 1), external puncture needle-assisted optical fiber passing through pork tissue and a porous polymer plate (Setup 2), single optical fiber passing through pork tissue and a porous polymer plate (Setup 3), and ordinary laser beam passing through pig tissue and a porous polymer plate (Setup 4). The thickness of the pork tissue is 60 mm. The experimental results are shown in Figure 5 (b) is shown. Figure 5 (b) It can be seen that Setup 3 and Setup 4 cannot detect the light energy received by the power meter below the tissue, while Setup 1 and Setup 2 can detect the light energy received by the power meter below the tissue, indicating that with the assistance of the puncture needle, the optical fiber can effectively transmit light energy to deep tissue.

[0096] like Figure 5 As shown in (d), pig tissue was used as an optical barrier to simulate in vivo heating. Plastic tubes filled with the photothermal conversion agent BL@F127 were placed on pig tissues of different thicknesses. The experimental results are shown in Figure 5 (c) and (e). Figure 5 (c) It can be seen that as the thickness of pork increases, there is no energy loss in the light transmission of the three optical fibers compared with the traditional exogenous laser; Figure 5 (e) It can be seen that as the thickness of the pork increases, the temperature inside the plastic tube does not change under the irradiation of the three optical fibers compared with the traditional exogenous laser.

[0097] In order to characterize the temperature distribution and thermodynamic properties of the internal thermal field, such as Figure 5 As shown in Figure (f), a custom-made temperature measurement device was used to detect the thermal conduction of the photothermal hotspot: the photothermal converter BL@F127 was injected into the tumor, and the needle carrying the thermocouple was tied to a ruler. Then, the ruler was guided by an injection pump to uniformly control the thermocouple away from the tip of the optical fiber (power: 110mW). At the same time, a third-class boundary condition was applied outside the tumor model, the heat transfer temperature was set to the ambient temperature, and the natural convection heat transfer coefficient was used to perform a three-dimensional steady-state heat conduction numerical calculation for the same tumor model and heat source power. The results are shown in Figure 5. Figure 5 (g) and (h). Figure 5 (g) It can be seen that the results of computer simulation are consistent with the actual experimental results, thus verifying each other and confirming the effectiveness of the experimental system and experimental method; Figure 5 (h) It can be seen that the numerical simulation shows that the strong scattering spherical end polymer fiber can achieve a wider range of uniform heating by providing 360° uniform irradiation. In addition, the heating area of ​​the three types of optical fibers was compared: water and the photothermal converter BL@F127 were irradiated with laser light through quartz fiber, flat end polymer fiber and strong scattering spherical end polymer fiber, respectively, with a laser power of 110mW. The thermal imaging results are shown in Figure 2. Figure 5 As shown in (i), Figure 5 As can be seen in (i), the strongly scattering spherical-end polymer optical fiber has a larger heat generation area, confirming the advantage of the large excitation volume of the spherical end, which is consistent with the computer simulation results.

[0098] (E) Fluorescence imaging and in vivo photothermal properties of tumor tissue:

[0099] from Figure 6 As can be seen in (a), the photothermal conversion agent BL@F127 was enriched in the subcutaneous tumor of mice for 12 days. Figure 6 (b) In vivo NIR-II fluorescence images show that the photothermal conversion agent BL@F127 can be enriched in the in situ tumor for 12 days, with a long-term retention effect, avoiding accumulation in non-lesion areas. Figure 6 (c) As can be seen, as the tumor continues to grow, the NIR-II fluorescence intensity change curve shows that the overall brightness of the fixed dose of photothermal conversion agent BL@F127 in the tumor area decreases.

[0100] The photothermal conversion agent BL@F127 was injected into the subcutaneous HeLa tumor of mice, and the tumor area was continuously irradiated with a 1064nm laser with a power of 110mW for photothermal therapy and photothermal images were captured. Figure 6 (d) As can be seen, within 4 minutes, the temperature in the group using the three optical fibers combined with the photothermal converter BL@F127 rapidly rose and stabilized at 44°C. In contrast, the tumor temperature in the PBS group changed less, demonstrating the excellent photothermal conversion capability of the photothermal converter BL@F127. Furthermore, when the tumor site reached the same temperature, the heat-generating area of ​​the photothermal converter BL@F127 combined with a strongly scattering spherical-end polymer fiber was significantly greater than that of the photothermal converter BL@F127 combined with a quartz fiber and the BL@F127 combined with a flat-end polymer fiber. (The power of 110 mW refers to the power of forward scattered light measured with an optical power meter).

[0101] (F) In vivo animal experiments using the photothermal conversion agent BL@F127 combined with three optical fibers:

[0102] The tumor sites of tumor-bearing mice were covered with pork to simulate the real deep tumor for treatment: a single intratumoral injection of 25 μL of photothermal conversion agent BL@F127 (0.8 mg / mL) was performed, and irradiation was performed every other day. The tumors of the mice were dissected on the 14th day. The results are as follows Figure 7 As shown in (a) to (i).

[0103] Depend on Figure 7(a) It can be seen that four 15-minute irradiations of quartz fiber or flat-end polymer fiber and the photothermal converter BL@F127 laser can achieve a good tumor inhibition effect, while three 5-minute irradiations of strongly scattering spherical-end polymer fiber and the photothermal converter BL@F127 laser can achieve a good tumor inhibition effect.

[0104] Depend on Figure 7 (b) It can be seen that after laser irradiation with three types of optical fibers and the photothermal converter BL@F127, the photothermal content in mice showed an upward trend after photothermal treatment.

[0105] Depend on Figure 7 (c) It can be seen that compared with other groups, the photothermal conversion agent BL@F127+strong scattering spherical end polymer optical fiber group has the smallest volume, and the tumor volume growth curve of each group (n=5, *P<0.05vs PBS+QOF; #P<0.05). Figure 7 (d) It can be seen that among the tumor tissues removed from the six groups after 14 days, the tumor in the group with photothermal conversion agent BL@F127+strong scattering spherical end polymer optical fiber was the smallest. Figure 7 (e) It can be seen that after the treatment period, the tumor weight of the BL@F127+flat-end polymer fiber group and the BL@F127+strong scattering spherical-end polymer fiber group was significantly reduced compared with the PBS group, PBS+QOF group, photothermal conversion agent BL@F127 group and BL@F127+QOF group. Figure 7 (f) It can be seen that in HE staining, the photothermal converter BL@F127 stained less pink in the cytoplasm of tumor tissue under laser irradiation, indicating leakage of intracellular contents. In TUNEL staining, the photothermal converter BL@F127+strong scattering spherical end polymer optical fiber group showed more green fluorescence signals, indicating a significant increase in the apoptosis rate, accompanied by abnormal cell morphology and nuclear disintegration.

[0106] Western blotting was used to detect tumor tissues. Figure 7 (g) to (i). Figure 7 (g) It can be seen that compared with the PBS group, PBS+QOF group and photothermal converter BL@F127 group, the expression levels of some classic apoptosis and pyroptosis related proteins in the three fiber + photothermal converter BL@F127 groups changed. Figure 7 (h) It can be seen that compared with the PBS group, PBS+QOF group and photothermal converter BL@F127 group, the protein expression levels of apoptosis-related proteins Bax, Bcl2, Caspase 3 and PARP1 in the three optical fiber + photothermal converter BL@F127 groups changed. Figure 7(i) Compared with the PBS group, the PBS+QOF group, and the photothermal converter BL@F127 group, the expression levels of pyroptosis-related proteins Caspase1 and Gasdermin D changed (n=3, *P<0.05 compared with PBS+QOF; #P<0.05). This suggests that the photothermal converter BL@F127 combined with the three optical fibers exerts its anti-tumor effect mainly through apoptosis and pyroptosis.

Claims

1. An optical fiber device based on a temperature-sensitive hydrogel, comprising a flexible conduit for injecting a photothermal conversion agent, characterized in that: Also included are polymer optical fibers for transmitting near-infrared laser light in the second region; The photothermal conversion agent is a temperature-sensitive hydrogel, which is made of non-ionic surfactant polyol and nanomaterial BLNPs; wherein the nanomaterial BL NPs is made of non-ionic surfactant polyol and organic molecule SW8.

2. The optical fiber device based on temperature-sensitive hydrogel according to claim 1, characterized in that: The mass ratio of the nonionic surfactant polyol to the nanomaterial BL NPs is 176-183:1; the mass ratio of the nonionic surfactant polyol used to prepare the nanomaterial BL NPs to the organic molecule SW8 is 10:

1.

3. The optical fiber device based on temperature-sensitive hydrogel according to claim 1, wherein: The nonionic surfactant polyol was Pluronic F-127.

4. The optical fiber device based on temperature-sensitive hydrogel according to claim 1, wherein: The polymer optical fiber is made of polylactic acid.

5. The optical fiber device based on temperature-sensitive hydrogel according to claim 1, wherein: The end of the polymer optical fiber is a spherical structure.

6. The optical fiber device based on temperature-sensitive hydrogel according to claim 1, wherein: The diameter of the end of the polymer optical fiber is 600 μm, and the diameter of the optical fiber excluding the end is 480-520 μm.

7. A method for preparing an optical fiber device based on a temperature-sensitive hydrogel according to any one of claims 1 to 6, characterized in that: The method includes preparing a temperature-sensitive hydrogel, specifically comprising: dissolving a nonionic surfactant polyol and nanomaterial BL NPs at 4°C to prepare a hydrogel solution, and then standing the solution at 38°C for at least 150 seconds to obtain a solidified temperature-sensitive hydrogel.

8. The method for preparing an optical fiber device based on a temperature-sensitive hydrogel according to claim 7, wherein: The method also includes preparing a polymer optical fiber, specifically comprising: immersing the end of a medium into molten polylactic acid, stretching the medium at a uniform speed, and allowing the polylactic acid at the end of the medium to solidify to form a polymer optical fiber; immersing the end of the polymer optical fiber into a polylactic acid solution, and then promoting solidification under ventilation conditions, and repeating this process multiple times so that the polylactic acid solidifies to form a spherical structure, thereby obtaining a strongly scattering spherical-end polymer optical fiber.

9. The method for preparing an optical fiber device based on a temperature-sensitive hydrogel according to claim 8, wherein: The speed of stretching the medium is 23 to 27 cm / min.

10. Use of the temperature-sensitive hydrogel-based optical fiber device according to any one of claims 1 to 6 in photothermal therapy.

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