AU2021100578A4

AU2021100578A4 - Use of thermosensitive material in preparation of injection for protecting perihepatic structure during thermal ablation

Info

Publication number: AU2021100578A4
Application number: AU2021100578A
Authority: AU
Inventors: Jingjing Fu; Song Wang; Wei Yang
Original assignee: Beijing Institute for Cancer Research
Current assignee: Beijing Institute for Cancer Research
Priority date: 2021-01-29
Filing date: 2021-01-29
Publication date: 2021-04-22
Anticipated expiration: 2029-01-29

Abstract

The present disclosure provides use of a thermosensitive material in the preparation of an injection for protecting perihepatic structures during thermal ablation. The thermosensitive material is to protect the perihepatic structures during the thermal ablation of tumors adjacent to capsules of mammalian solid abdominal viscera. The injection material is in a liquid state with excellent fluidity at 0-4°C and is transformed from a liquid phase to a non-flowing solid or semi-solid phase when temperature increases to 34-37°C, and the thermosensitive material can retain in an injection site; preferably, the injection material is transformed into the non-flowing solid or semi-solid phase within 10 secs to 3 min. The injection prepared from the thermosensitive material is used for intraperitoneal injection instead of a conventional injection, so that viscera are separated from peripheral structures susceptible to thermal damage, achieving an enough protective thickness; thus, the thermal ablation can be safer, overcoming the defects of large fluidity, short retention in a target region, durable perfusion requirement of a conventional liquid.

Description

USE OF THERMOSENSITIVE MATERIAL IN PREPARATION OF INJECTION FOR PROTECTING PERIHEPATIC STRUCTURE DURING THERMAL ABLATION

TECHNICAL FIELD The present disclosure relates to the field of medicine, and in particular to use of a thermosensitive material in the preparation of an injection for protecting perihepatic structures during thermal ablation, and more particularly to use of a thermosensitive material in the preparation of an injection for protecting perihepatic structures during thermal ablation in the process of thermal ablation of tumors adjacent to capsules of mammalian solid abdominal viscera. BACKGROUND "Thermal tumor ablation" is defined as a therapy based on the direct use of thermal energy in a tumor (or a plurality of tumors) to destroy or completely eradicate the tumor, including radiofrequency ablation, microwave ablation, laser ablation, and high-intensity focused ultrasound (HIFU). Among them, the most widely used thermal ablation technology is RFA. Radiofrequency ablation (RFA): Guided by means of ultrasound or CT/MRI imaging, a needle electrode is inserted into a tumor, and radiofrequency energy is emitted through the needle electrode; thus, ion oscillation occurs in local tumor tissues, and heat is generated by friction to reach a temperature of higher than 60°C, leading to tumor tissue protein denaturation and final coagulative necrosis and achieving the purpose of killing the tumor. RFA is an effective minimally invasive means of clinical treatment of liver cancer. The mortality of RFA is about 0.3-4.5%, and the incidence of serious complications is about 2.2-8.9%. These results confirm that RFA is a relatively low-risk treatment for liver tumors. Currently, RFA has been widely used to treat solid tumors in abdominal cavity, such as liver, kidneys and spleen. However, the risk of thermal damage increases regarding the treatment of subcapsular tumors via subcutaneous approach, such as use of adjacent diaphragms, gallbladder, and gastrointestinal tract. In addition, one limitation in the process of subcapsular tumor treatment is burning damage and pain from the adjacent parietal peritoneum. Therefore, the prevention and treatment of important perihepatic structural damage and related complications are receiving increasing attention.

In order to reduce injuries to important perihepatic structures and prevent related complications, previous studies reported that percutaneous injection of liquid or gas to make artificial ascites to isolate the liver from peripheral structures susceptible to thermal damage, enabling safer thermal ablation. Commonly used liquids include normal saline, 5% dextrose solution, etc.; gases include carbon dioxide (C0 2 ) and so forth. Because these conventional injections have large fluidity, retain in target areas in a short time and can be rapidly absorbed, it is sometimes difficult to achieve an adequate separation effect, still causing thermal damage to perihepatic structures. Therefore, a large amount of fluid (1-3 L) or continuous infusion is required to ensure that the fluid reaches a sufficient protective thickness, often resulting in postoperative discomfort in patients. Use of C02 as an artificial ascites material affects tumor ultrasonic imaging. A balloon catheter is deployed into the perihepatic area by percutaneous puncture, the balloon is inflated to increase volume, and perihepatic diaphragm or intestine is push aside. By means of such mechanical separation, intrahepatic thermal ablation zone is separated from the important intrahepatic structures to prevent injury. After treatment, the balloon is deflated and the catheter is withdrawn from the body. A balloon catheter is deployed into the perihepatic area by percutaneous puncture. Due to a short diameter of the catheter, puncture operation increases human body traumas, leading to increased complications. In case of abdominal adhesions, the mechanical separation by balloon inflation easily leads to perihepatic laceration, resulting in bleeding or intestinal wall laceration. In addition, this technology requires a skilled operator, and the balloon needs to be deployed in an exact location, without offset. Finally, the technology is generally conducted under the guidance of CT, which has radioactive radiation that causes specific damage to the human body. Therefore, there is an urgent need for an effective protective means for reducing damage to perihepatic structures during thermal ablation of subcapsular tumors. SUMMARY An objective of the present disclosure is to provide use of a thermosensitive material in the preparation of an injection for protecting perihepatic structures during thermal ablation in the process of thermal ablation of tumors adjacent to capsules of mammalian solid abdominal viscera. Another objective of the present disclosure is to provide an injection for protecting perihepatic structures during thermal ablation.

To achieve the above objectives, in one aspect, the present disclosure provides use of a thermosensitive material in the preparation of an injection for protecting perihepatic structures during thermal ablation. The thermosensitive material is to protect the perihepatic structures during the thermal ablation of tumors adjacent to capsules of mammalian solid abdominal viscera. The injection material is in a free-flowing liquid state at 0-4°C (ice box) and is rapidly transformed into a non-flowing solid or semi-solid phase when temperature increases to 25-37°C (room temperature to body temperature) (which can retain in situ). It is to be understood that the non-flowing in the present disclosure refers to the loss of fluidity of a liquid like water which will not be uniformly dispersed as a liquid at rest but will generally retain a solid or semi-solid form having a certain shape. The semi-solid form can be understood as a gel-like or frost-like state which is capable of changing shape within a certain range, between a free-flowing liquid state and a solid form which does not undergo a large shape change. According to some embodiments of the present disclosure, herein, the thermosensitive material maintains a liquid state at 0-4°C (ice box temperature). It is to be understood that maintaining the liquid state at 0-25°C according to the present disclosure means maintaining a liquid state capable of free flowing at least at 0 25°C, so that the thermosensitive material may be injected into the abdominal cavity in this temperature range through injection tools such as a syringe or catheter. The present disclosure does not preclude the possibility of holding the liquid state below 0°C or above 25°C. The thermosensitive material of the present disclosure may be transformed from a liquid state to a solid or semi-solid state as long as the temperature is higher than room temperature and close to human body temperature (e.g., 37°C). The thermosensitive material of the present disclosure increases in liquid viscosity with increasing temperature and transforms into a solid or semi-solid state within 10 secs to 3 min at 3C or above (close to body temperature). Herein, the thermosensitive material of the present disclosure has the highest viscosity at 40-50°C and may retain in an injection site without fluidity. It is to be understood that the thermosensitive material of the present disclosure should meet the safety standards of medical materials and be safe to the human body without causing fatal poisoning, infection and even rejection reaction. The thermosensitive material of the present disclosure may be biodegradable or may be manually removed again after the thermal ablation is finished, whereas according to some embodiments of the present disclosure, herein, the thermosensitive material may be absorbed by the body of a mammal within one month, without residue in vivo. According to some embodiments of the present disclosure, herein, the thermosensitive material may contain at least one of medical thermosensitive polymer and matrigel. Materials that satisfy the above conditions are well known to those skilled in the art and can be selected by those skilled in the art from the conventional materials in the art based on the description of the present disclosure and their own knowledge of the prior art. According to some embodiments of the present disclosure, herein, the medical thermosensitive polymer may be a thermosensitive polymeric hydrogel. The thermosensitive polymeric hydrogel of the present disclosure may, for example, be a block copolymer, random copolymer, grafted copolymer or branched polymer or copolymer conventionally used in the art. Polyoxyalkylene block copolymers such as poloxamers, and more specifically, poloxamers P407, 188, 338, 1107 and 1307 and poloxamers F127 and 108 (Pluronic) may be further included therein. For example, block copolymers, random copolymers, grafted copolymers or branched polymers or copolymers used in the art as vascular embolic materials may be included. Further for example, the thermosensitive polymeric hydrogel may be poly(N acrylamide) hydrogels. The poly(N-acrylamide) hydrogels may be selected from specific types conventional in the art, such as poly(N-n-propylacrylamide-co-N-isopropylacrylamide), N isopropylacrylamide, poly(N-isopropylacrylamide-co-acrylamide), and poly(N isopropylacrylamide-co-acrylic acid). It is to be understood that main components of the injection material of the present disclosure may be selected from at least one of poloxamers, poly(N-acrylamide) hydrogels, oligoesters, and chitosans. According to some embodiments of the present disclosure, the matrigel may be Matrigel Basement Membrane Matrix. According to some embodiments of the present disclosure, herein, the injection may further contain one of water for injection, normal saline, and aqueous solution of dextrose for injection.

According to some embodiments of the present disclosure, the mass percent of the water for injection, normal saline or aqueous solution of dextrose for injection may be 30%-90% of the total weight of the injection. According to some embodiments of the present disclosure, the injection solution may further contain additional materials. The additional materials are to further improve the performance of the injection material. Those skilled in the art may select conventional materials in the prior art to add as desired, such as improving the storage performance and usability thereof; according to some embodiments of the present disclosure, the additional materials may be selected from one of humectants, preservatives, antioxidants, emulsifiers and thickeners, or a combination thereof. It is to be understood that the amount of the additional materials may be determined according to the performance of the additional materials selected, that is, after ensuring the addition of the additional materials, injection material prepared may still transform from a liquid state to a solid or semi-solid state at a temperature approaching human body temperature and may maintain a free-flowing liquid state at a lower temperature (at least 0-4°C); according to some embodiments of the present disclosure, the total weight of the additional materials may be 0.5%-10% of the total weight of the injection material. According to some other embodiments of the present disclosure, the total weight of the additional materials may account for 0.5%-5% of the total weight of the injection material. According to some other embodiments of the present disclosure, the total weight of the additional materials may account for 0.5%-1% of the total weight of the injection material. In addition, in order to increase anti-tumor efficacy and imaging functions, the injection may further be supplemented with a contrast agent and/or a chemotherapeutic agent. Herein, the amount of the contrast agent and/or chemotherapeutic agent may be determined according to the usage and the conventional clinical dosage of the selected contrast agent and/or chemotherapeutic agent, without further creative work by those skilled in the art. According to some embodiments of the present disclosure, the amount of the contrast agent and/or chemotherapeutic agent is 1%-20% of the total weight of thermosensitive injection.

According to some more specific embodiments of the present disclosure, herein, the matrigel may be Matrigel Basement Membrane Matrix (BD, U.S.A.). According to some still more specific embodiments of the present disclosure, herein, the injection may consist of poloxamer (P407) and water for injection. Herein, more specifically, the mass percent of the poloxamer may be 15%-33% of the total weight of the injection. According to some still more specific embodiments of the present disclosure, herein, the injection may consist of poly(N-n-propylacrylamide-co-N-isopropylacrylamide) and/or water for injection. Physical phase transition properties of the injection material: At 0-4°C (ice box temperature), the injection material has maximum fluidity and is in a liquid form; at 25 37°C higher than room temperature, especially at 37°C (body temperature), the injection material undergoes rapid phase transition (within 10 secs to 3 min), and the fluidity thereof decreases significantly, showing a solid or semi-solid state; at 40-50°C, the injection material has maximum viscosity. Before RFA, thermosensitive injection material is stored and transported in the ice box (at 0-4°C) to maintain in a liquid state and be easy to percutaneously inject intraperitoneally. Ultrasound guidance may display the separation among liquid separation zones, abdominal viscera and peripheral structures (diaphragm, gallbladder, and intestine) in real time. During RFA of a subcapsular tumor, an appropriate amount of thermosensitive injection is injected between thermal ablation zone and important perihepatic structures; at body temperature (37C) and a temperature from a ablation needle (above 50°C), the thermosensitive injection shows a decrease in fluidity, undergoes rapid phase transition into a solid state, and form an isolated protective layer to achieve a relatively safe protective thickness. According to some embodiments of the present disclosure, herein, the solid abdominal viscera may include liver, kidneys, pancreas or spleen. According to some embodiments of the present disclosure, herein, the perihepatic structures may include diaphragm, gallbladder, gastrointestinal tract, abdominal wall, great vessels or ureters. According to some embodiments of the present disclosure, herein, the thermal tumor ablation may be a treatment technique for eliminating the tumors by generating coagulative necrosis by local tissue hyperthermia. According to some embodiments of the present disclosure, herein, the thermal tumor ablation may include RFA, microwave ablation, laser ablation, and HIFU.

According to some embodiments of the present disclosure, herein, the mammal may be human. According to some embodiments of the present disclosure, herein, the injection material may have a dose of 20-200 mL in the human body. In another aspect, the present disclosure provides an injection for protecting perihepatic structures during thermal ablation, which is to protect the perihepatic structures during the thermal ablation of tumors adjacent to capsules of mammalian solid abdominal viscera; the injection includes the following components: 10%-70% by weight of thermosensitive material, 30%-90% by weight of water for injection, normal saline or aqueous solution of dextrose for injection, 0%-10% by weight of additional material, and 0%-20% by weight of contrast agent and/or chemotherapeutic agent; the thermosensitive material is in a free-flowing liquid state at 0-25°C, and is transformed from a liquid phase to a non-flowing solid or semi-solid phase when temperature increases to 37C. According to some preferred embodiments of the present disclosure, the injection may include the following components: 10%-70% by weight of thermosensitive material, and 30%-90% of water for injection, normal saline or aqueous solution of dextrose for injection. According to some preferred embodiments of the present disclosure, the thermosensitive material may be in a free-flowing liquid state at 0-4°C. According to some preferred embodiments of the present disclosure, the thermosensitive material may be transformed into the non-flowing solid or semi-solid phase within 10 secs to 3 min. According to some preferred embodiments of the present disclosure, the solid abdominal viscera may include liver, kidneys, pancreas or spleen. According to some preferred embodiments of the present disclosure, the perihepatic structures may include diaphragm, gallbladder, gastrointestinal tract, abdominal wall, great vessels or ureters. According to some preferred embodiments of the present disclosure, the mammal may be human. According to some preferred embodiments of the present disclosure, the injection material may have a dose of 20-200 mL in the human body. According to some preferred embodiments of the present disclosure, the additional materials may be selected from one of humectants, preservatives, antioxidants, emulsifiers and thickeners, or a combination thereof.

According to some preferred embodiments of the present disclosure, the thermosensitive material may be biodegradable and absorbed by the mammalian body within one month. According to some preferred embodiments of the present disclosure, the thermosensitive material may contain at least one of medical thermosensitive polymer and matrigel. According to some preferred embodiments of the present disclosure, the medical thermosensitive polymer may be a thermosensitive polymeric hydrogel. According to some preferred embodiments of the present disclosure, the medical thermosensitive polymer may be selected from at least one of poloxamers, poly(N acrylamide) hydrogels, oligoesters, and chitosans. According to some preferred embodiments of the present disclosure, the matrigel may be Matrigel Basement Membrane Matrix. According to some preferred embodiments of the present disclosure, the thermal tumor ablation may be a treatment technique for eliminating the tumors by generating coagulative necrosis by local tissue hyperthermia. According to some preferred embodiments of the present disclosure, the thermal tumor ablation may include RFA, microwave ablation, laser ablation, and HIFU. In summary, the present disclosure provides use of a thermosensitive material in the preparation of an injection for protecting perihepatic structures in the process of thermal ablation of tumors adjacent to capsules of mammalian solid abdominal viscera. The technical solutions of the present disclosure have the following advantages: In order to reduce the damage of the thermal ablation to important structures (diaphragm, gallbladder, gastrointestinal tract, abdominal wall, ureters, etc.) around the solid abdominal viscera and prevent related complications, a thermosensitive injection material is used for intraperitoneal injection instead of a conventional injection, so that viscera are separated from peripheral structures susceptible to thermal damage, achieving an enough protective thickness; thus, the thermal ablation can be safer, overcoming the defects of large fluidity, short retention in a target region, durable perfusion requirement of a conventional liquid. When ablating a visceral subcapsular tumor, this material is percutaneously and intraperitoneally injected around the viscera adjacent to thermal ablation zones to create separation zones that effectively reduce or eliminate the thermal damage to adjacent structures such as diaphragm, gastrointestinal tract, abdominal wall, or ureters.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a comparison of ultrasound images showing the separation effect of a thermosensitive injection material versus normal saline used during thermal ablation in Example 1; FIG. 2 illustrates a comparison of the post-treatment incidence of thermal damage to perihepatic structures in three groups after treatment with thermosensitive injection material, with normal saline, and without any protective measure during thermal ablation in Example 1, respectively; FIG. 3 illustrates a separation zone for protecting gastrointestinal structures formed by percutaneous injection of thermosensitive Matrigel Basement Membrane Matrix between liver and gastrointestinal tract, where 1 presents a tumor, 2 presents a syringe, 3 presents an injection, 4 presents a radiofrequency needle electrode, 5 presents an intestine, and 6 presents a separation zone formed by injection curing; FIG. 4 illustrates the effect of perihepatic injection of Matrigel Basement Membrane Matrix in a rat experiment, where a semi-solid gel can be formed perihepatically, protecting adjacent diaphragm, abdominal wall and intestine. DETAILED DESCRIPTION The implementation process and the beneficial effects produced by the present disclosure will be described in detail below in conjunction with specific embodiments to help readers better understand the essence and characteristics of the present disclosure and not to limit the implementable scope of the present disclosure. Embodiment 1 A thermal injection was prepared from Matrigel Basement Membrane Matrix (BD, U.S.A.), which was previously used in cell culture tests. The main components thereof include laminin, collagen type IV, nestin, and heparan sulfate proteoglycan, as well as a temperature-sensitive hydrogel. Matrigel rapidly gels at 37°C, and therefore is freeze thawed overnight on ice at 0-4°C (at above 4°C, it partially gels with increasing temperature) when dissolving. All supplies should be placed in an ice bath before use. The Matrigel must be handled using a precooled syringe or catheter. The BD Matrigel Basement Membrane Matrix can form a semi-solid gel within 1 min at 37°C and polymerizes into a three-dimensional matrix with biological activity; the BD Matrigel Basement Membrane Matrix can simulate the structure, composition, physical characteristics and functions of a cellular basement membrane in vivo and is conducive to the in vitro cell culture and differentiation, as well as research on cell morphology, biochemical function, migration, infection and gene expression. High-concentration Matrigel is suitable for investigating in vivo angiogenesis and tumor cell migration and establishing tumor models. One vial (10 mL) of BD Matrigel Basement Membrane Matrix was placed at 0-4°C for 24-48 h, to remain in a liquid state and stored in an ice box when in use. Sprague Dawley rats were used in the experiment. RFA was conducted on a liver tumor 1 adjacent to the gastrointestinal tract 5 using a radiofrequency needle electrode 4; before treatment, a suitable amount (10 mL) of Matrigel Basement Membrane Matrix 3 was injected into the space between liver ablation zone and gastrointestinal tract 5 using a syringe 2, and a 5-10 mm thick separation zone 6 is formed (FIG. 3). The radiofrequency needle electrode was inserted into the liver percutaneously under ultrasonic guidance until a needle tip was in the hepatic subcapsular region adjacent to the separation zone formed by the Matrigel Basement Membrane Matrix. Animal body temperature (about 37C) and ablation needle temperature (above 50°C) reduced the fluidity of the Matrigel Basement Membrane Matrix, which was in a solid state within 1 min and formed a separation zone in the injection zone to effectively reduce the thermal damage of RFA to the gastrointestinal tract (FIG. 4). Ablation apparatus was a CC-1-220 monopolar RFA generator (Valleylab, Tyco Healthcare, U.S.A.) with a generator frequency of 480 kHz and a maximum power output of 40 W; 17G Cool-tip electrode was 15 cm long and 0.7 cm away from the tip. The course of treatment was the same as previous RFA parameters (tip temperature 70°C and ablation zone edge temperature 50°C). Treatment lasted for 5 min, and observation was conducted 30 min after treatment; in case of no active bleeding within the abdominal cavity, the rats could be returned for recovery. There was no special treatment, and the Matrigel Basement Membrane Matrix was absorbed within one month after treatment. Normal saline group was applied in exactly the same way as Matrigel Basement Membrane Matrix group. As shown in FIG. 1, there is a significant difference in the thickness of the separation zone between Matrigel group and normal saline group, especially at 5 min (P< 0.001). As shown in FIG. 2, the incidence of thermal damage to pre-hepatic structures differs significantly among the Matrigel Basement Membrane Matrix group, normal saline group, and RFA alone group (without any protective measures taken). The damage rate of peripheral structures adjacent to the ablation zone was 92.3% (12/13) in the RFA alone group, significantly higher than that in the normal saline group (57.1%, 8/14, P = 0.037) and the lowest in the Matrigel group (7.1%, 1/14, P < 0.001).

Embodiment 2 A thermosensitive injection was prepared from temperature-sensitive poloxamer aqueous solution, 15.4% of which was poloxamer P407. This polymeric hydrogel is a mixture system of water and three-dimensional crosslinked network composed of polymer, which is traditionally used as a non-ionic surfactant and has been widely used in the field of controlled drug release in recent years. This hydrogel exhibits a low viscosity liquid state at around 20°C (room temperature) and becomes a gel through phase transition at 34-37°C (close to body temperature), with the highest viscosity at 50°C. A poloxamer aqueous solution (Sigma) was placed at room temperature and maintained a liquid state. Sprague Dawley rats were used in the experiment. RFA was conducted on a liver tumor adjacent to the diaphragm; before treatment, an appropriate amount (10 mL) of poloxamer aqueous solution was injected into the space between liver ablation zone and diaphragm under ultrasonic guidance to form a 5-10 mm thick separation zone. A radiofrequency needle electrode was inserted into the liver percutaneously under ultrasonic guidance until a needle tip was in the hepatic subcapsular region adjacent to the separation zone formed by the poloxamer aqueous solution. Animal body temperature (about 37C) and ablation needle temperature (above 50°C) reduced the fluidity of the injection, which was in a solid state within 1 min and formed a separation zone in the injection zone to effectively reduce the thermal damage of RFA to the diaphragm. Embodiment 3 A thermosensitive injection was prepared from temperature-sensitive nano-hydrogel (N-isopropylacrylamide-co-acrylamide) (referred to as temperature-sensitive nano-gel) (developed by the Institute of Materia Medica, College of Life Science and Technology, Huazhong University of Science and Technology). This is an intelligent nanomaterial that produces structural and performance changes according to slight changes in temperature and is currently used in the field of endovascular embolization. It has been shown that temperature-sensitive nano-gels have low sol viscosity and high gel strength, along with rapid thermosensibility and significant thixotropy. At room temperature, about 20°C, the temperature-sensitive nano-gel is in a liquid state with good fluidity. When the temperature was increased to 34-37°C, the temperature-sensitive nano-gel completely loses fluidity in 12 secs and becomes a gel state. Sprague Dawley rats were used in the experiment. RFA was conducted on a liver tumor adjacent to the abdominal wall; before treatment, an appropriate amount (10 mL) of temperature-sensitive nano-hydrogel was injected into the space between liver ablation zone and abdominal wall under ultrasonic guidance to form a 5-10 mm thick separation zone. A radiofrequency needle electrode was inserted into the liver percutaneously under ultrasonic guidance until a needle tip was in the hepatic subcapsular region adjacent to the separation zone formed by the temperature-sensitive nano-hydrogel. Animal body temperature (about 37°C) and ablation needle temperature (above 50°C) reduced the fluidity of the injection, which was in a solid state within 1 min and formed a separation zone in the injection zone to effectively reduce the thermal damage of RFA to the diaphragm.

Claims

CLAIMS:

1. Use of a thermosensitive material in the preparation of an injection for protecting perihepatic structures during thermal ablation, wherein the thermosensitive material is to protect the perihepatic structures during the thermal ablation of tumors adjacent to capsules of mammalian solid abdominal viscera, and the thermosensitive material is in a free-flowing liquid state at 0-25°C, and preferably at 0-4°C and is transformed from a liquid phase to a non-flowing solid or semi-solid phase when temperature increases to 34-37°C; preferably the thermosensitive material is transformed into the non-flowing solid or semi-solid phase within 10 secs to 3 min; preferably, the solid abdominal viscera comprise liver, kidneys, pancreas or spleen; preferably, the perihepatic structures comprise diaphragm, gallbladder, gastrointestinal tract, abdominal wall, great vessels or ureters; the mammal is human; preferably, the injection material has a dose of 20-200 mL in the human body.

2. The use according to claim 1, wherein the thermosensitive material is biodegradable and absorbed by the mammalian body within one month.

3. The use according to claim 1, wherein the thermosensitive material comprises at least one of medical thermosensitive polymer and matrigel; preferably the medical thermosensitive polymer is a thermosensitive polymeric hydrogel, and more preferably at least one of poloxamers, poly(N-acrylamide) hydrogels, oligoesters, and chitosans; preferably the matrigel is Matrigel Basement Membrane Matrix; preferably, the injection further comprises one of water for injection, normal saline and aqueous solution of dextrose for injection; preferably, the mass percent of the water for injection, normal saline or aqueous solution of dextrose for injection is 30-90% of the total weight of the injection; wherein the injection further comprises additional materials; preferably, the total weight of the additional materials is 0.5-10%, more preferably 0.5-5%, and most preferably 0.5-1% of the total weight of the injection; preferably, the additional materials are selected from one of humectants, preservatives, antioxidants, emulsifiers and thickeners, or a combination thereof; wherein the injection further comprises a contrast agent and/or a chemotherapeutic agent; wherein the thermal tumor ablation is a treatment technique for eliminating the tumors by generating coagulative necrosis by local tissue hyperthermia; preferably, the thermal tumor ablation comprises radiofrequency ablation (RFA), microwave ablation, laser ablation, and high-intensity focused ultrasound (HIFU).

4. An injection for protecting perihepatic structures during thermal ablation, wherein the injection is to protect the perihepatic structures during the thermal ablation of tumors adjacent to capsules of mammalian solid abdominal viscera; the injection comprises the following components: 10%-70% by weight of thermosensitive material, 30%-90% by weight of water for injection, normal saline or aqueous solution of dextrose for injection, %-10% by weight of additional material, and 0%-20% by weight of contrast agent and/or chemotherapeutic agent; the thermosensitive material is in a free-flowing liquid state at 0-25°C, and preferably at 0-4°C and is transformed from a liquid phase to a non flowing solid or semi-solid phase when temperature increases to 34-37°C; preferably the thermosensitive material is transformed into the non-flowing solid or semi-solid phase within 10 secs to 3 min; preferably, the solid abdominal viscera comprise liver, kidneys, pancreas or spleen; preferably, the perihepatic structures comprise diaphragm, gallbladder, gastrointestinal tract, abdominal wall, great vessels or ureters; the mammal is human; preferably, the injection material has a dose of 20-200 mL in the human body; preferably, the additional materials are selected from one of humectants, preservatives, antioxidants, emulsifiers and thickeners, or a combination thereof.

5. The injection according to claim 4, wherein said thermosensitive material is biodegradable and absorbed by the mammalian body within one month; wherein the thermosensitive material comprises at least one of medical thermosensitive polymer and matrigel; preferably the medical thermosensitive polymer is a thermosensitive polymeric hydrogel, and more preferably at least one of poloxamers, poly(N-acrylamide) hydrogels, oligoesters, and chitosans; preferably the matrigel is Matrigel Basement Membrane Matrix; wherein the thermal tumor ablation is a treatment technique for eliminating the tumors by generating coagulative necrosis by local tissue hyperthermia; preferably, the thermal tumor ablation comprises RFA, microwave ablation, laser ablation, and HIFU.