Preparation and application of the hottest bioabso

2022-08-24
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Preparation and application of bioabsorbable fiber

bioabsorbable fiber is the raw material of bioabsorbable medical textiles. This paper comprehensively introduces the types of bioabsorbable fibers and the preparation technology, properties and applications of major bioabsorbable fibers such as chitin, collagen, alginate, PLA, PGA, PCL and PHB

medical textiles are one of the branches of industrial textiles, and their use in the medical field is becoming more and more important. Taking the United States as an example, the sales of medical textiles in 2000 was $76 billion, with an average annual growth rate of 10% in recent years

biomedical textiles are mainly made of biomedical fibers. Biomedical fibers can contact and interact with life systems, and can diagnose, treat, replace, repair or induce regeneration of cells, tissues and organs. Because biomedical fibers have high added value and show considerable market prospects in practical applications, they have become a research hotspot all over the world

the research of biomedical fibers in China started in 1978. By the 1990s, more basic research results and practical technologies emerged, which made China's biomedical fiber material research level close to the international level, and reached the international advanced level in some fields. Jinan experimental machine factory is the largest experimental machine production base in China. Among them, the solvent cellulose hollow fiber artificial kidney developed by Donghua University The polypropylene hollow fiber artificial lung developed by Fudan University is one of them

Donghua University's patented production line with an annual output of 5 tons of chitosan fiber

at present, China's biomedical fiber industry is in the process of gestation, and a number of biomedical fibers and devices (organs) are being industrialized

types of biomedical fibers

due to the crystallization of multidisciplinary technology in biomedical fiber materials, there are different classification methods. According to the source of raw materials, biomedical fiber materials include metal (such as stainless steel wire), inorganic non-metal (such as alumina fiber) and polymer biomedical fibers, of which polymer biomedical fibers can be divided into natural polymer based and synthetic polymer based biomedical fibers according to the source; According to the interaction between materials and living tissue, biomedical fibers can be divided into bio inert fibers, bio active fibers and bio absorbable fibers

bioabsorbable fiber is also called biodegradable fiber. This kind of material is gradually degraded in the body, and the degradation products are absorbed and metabolized by the body. It is widely used in the medical field

the types of bioabsorbable fibers are: natural polymer based bioabsorbable fibers, including chitin and its derivatives, collagen fibers, alginate fibers, etc; Synthetic polymer based bioabsorbable fibers, including polyglycolide (PGA) fibers, polylactic acid (PLA) fibers, polyglycolide lactide (PGLA) fibers, polycaprolactone (PCL) fibers, etc

preparation technology and performance

natural polymer based bioabsorbable fibers

chitin fibers

chitin widely exists in the wings or shells of arthropods (spiders, crustaceans) and the cell walls of fungi and algae. In nature, the annual biosynthesis is about 10 billion tons, which is the second largest organic resource on the earth except cellulose

chitin is treated with concentrated alkali and deethylated to produce chitosan. Chitin contains ethyl and hydroxyl, and chitosan contains hydroxyl and amino. Both of them produce a series of derivatives through chemical reaction, collectively referred to as chitin substances

chitin fibers can be manufactured by wet spinning, dry spinning and dry wet spinning processes. So far, chitin and chitosan fibers have been produced by wet spinning process. Chitin uses an organic solvent with excellent solubility, plus appropriate lithium chloride to help dissolve, and chitosan uses dilute acid as the solvent

chitin fibers are widely used in the medical field. For example, chitin fibers can stop bleeding and coagulate blood, so the fiber felt made of them is a good hemostatic product. In addition, chitin fibers can be made into various bandages and gauze, which will degrade naturally after being discarded and will not pollute the environment. In recent years, they have been equipped by the United States in the army

as early as in ancient documents such as Shennong materia medica classic, compendium of Materia Medica, dietotherapy Materia Medica, it was clearly recorded that chitin has the functions of attacking poison, dispersing wind and activating blood circulation, dredging pulse and detumescence, hemostasis and muscle regeneration. Chitin fiber is non-toxic, with the function of being completely absorbed by the human body due to the degradation of lysozyme in the human body. It has little immunogenicity to the human body, and has biological activities such as anti-inflammatory, analgesic and promoting wound healing

chitin fiber and chitosan underwear, underwear and socks have been on the market for many years. After clinical application in hospital, it has been proved to have good antibacterial properties. The antibacterial rate of pure spinners is more than 99%; The antibacterial rate of the blend is about 75%

at present, the breaking strength of chitin and chitosan fibers is low, especially the wet strength is far lower than the dry strength, which limits the processing and application. The chitosan fiber prepared by Donghua University has been tested by the chemical fiber product testing center of China Textile Industry Association. The linear density is 2.01dtex, the breaking strength is 2.0cn ~ 2.5cn/dtex, and the elongation at break is 90%, reaching the advanced level of similar foreign fibers

bacteriostasis test results of chitosan fibers and pure textiles (control the bacteriostasis rate of fibers to synthesize polymer based bioabsorbable fibers

polylactic acid and its copolymer fibers

polylactic acid (PLA) takes lactic acid as the basic raw material, in which L-lactic acid can be used to prepare biomedical polylactic acid fibers

pla can be synthesized in two ways: ring opening polymerization of lactide (cyclic dimer of lactic acid) and direct polymerization of lactic acid. PLA spinning can be realized by solution spinning and melt spinning, in which melt spinning has economic comparative advantages. Various current melt spinning processes (high-speed spinning one-step, spinning drawing two-step) used to produce polyester can be used

Shima Seiki of Japan successfully spun PLA melt in the laboratory in 1992. At present, the production of PLA fiber by melt spinning has entered the stage of commercial production

the project of "synthetic method and fiber preparation process of polylactic acid" undertaken by China Petrochemical Corporation Limited by Donghua University has passed the technical appraisal in July 2003. According to the determination of the chemical fiber product testing center of China Chemical Fiber Industry Association, the breaking strength of the tensile fiber is 4.0cn/dtex, and the breaking elongation is 31%

in vivo experiments show that PLA can undergo hydrolysis reaction, and the intermediate product of hydrolysis is lactic acid, which is the normal metabolite of sugar in the body. It can follow the metabolic pathway of lactic acid. The activities of all branches should be consistent with the overall deployment of the association to participate in biochemical metabolism in the body, and finally generate harmless small molecular water and carbon dioxide. Therefore, the polymer is non-toxic, non irritating, absorbable in the body, and has good biocompatibility

as PLA is a hydrophobic substance, the degradation cycle is not easy to control, so the synthesis of lactic acid copolymer has become one of the research hotspots of absorbable medical polymer materials in recent years, among which polyglycolide lactide (PGLA) is the most widely used. It is prepared by ring opening and bulk polymerization with a certain amount of glycolide and L-lactide under the action of organometallic catalysts

polylactic acid and its copolymer fibers have many uses in the medical field. For example, polylactic acid fibers can be used to strengthen polylactic acid in fracture internal fixation and greatly improve the initial strength of fixation materials; Or as a soluble drug carrier substrate for the preparation of sustained-release preparations and targeted drug delivery preparations; Using its mechanical properties and biodegradability, it can be used as drug carrier materials, artificial pipelines, artificial ligaments, artificial tendons, hernia patches, bandages, diapers and disposable work clothes in drug controlled release systems

polycaprolactone fiber

polycaprolactone (PCL) is a semi crystalline polymer with a melting point of 59 ° c~640 ° C and a glass transition temperature of 600 ° C. It has good flexibility and processability

pcl can be spun into fibers by melt spinning. Because the degradation time of PCL fiber is about 2 years, the biological absorption rate is often accelerated by copolymerization modification. For example, copolymerization of caprolactone with DLLA accelerates the biodegradation rate of fibers. After studying the preparation of PCL fiber, it is found that its mechanical properties are similar to polyolefin fiber, its flexibility is better than PLA fiber, and it has good biocompatibility

polyglycolide fiber

polyglycolide (PGA) fiber is also called polyglycolic acid fiber or polyglycolic acid fiber

pga is prepared by condensation polymerization of hydroxyacetic acid with antimony trioxide as catalyst, but its molecular weight is low. PGA with high molecular weight is prepared by ring opening polymerization of glycolide with antimony, zinc, lead and tin compounds as catalysts in industry. PGA can be spun into fibers by melt spinning, and the fibers are absorbed in living tissues within 10 to 18 weeks

main applications of bioabsorbable fibers

wound dressing

at present, the bioabsorbable fibers being developed and applied in wound protection are mainly collagen fibers, seaweed fibers and chitin fibers, which are very useful for the wound healing process. After cutting the above three fibers, they are made into non-woven fabrics, that is, wound dressing. This kind of dressing has excellent air permeability and moisture absorption, can keep the wound dry, avoid fatal infection, and solve the problem of effusion that is difficult to overcome by other dressings and external membranes

when alginate fiber is used in the wound contact layer, it interacts with the wound to produce sodium alginate and calcium alginate gel. This gel is hydrophilic, which allows oxygen to pass through but bacteria cannot, and promotes the formation of new tissues. Therefore, it is an ideal raw material for medical wound dressings. When changing the dressing made of this fiber, some fibers left on the wound do not need to be removed. Because a small amount of fiber can be slowly absorbed by soft tissue, which greatly reduces the pain of patients. Moreover, wound dressing made of calcium alginate fiber can accelerate wound healing

the chitosan wound dressing developed by Donghua University has been clinically applied in Changhai Hospital, Ruijin Hospital and Zhongshan Hospital Affiliated to Shanghai Second Military University. It has been proved to have the functions of stimulating the formation of new skin, accelerating the healing rate and reducing pain. It has a unique curative effect on curing burns, scalds, bedsores and body surface ulcers. It has obtained a production license and a hygiene license, and has entered the scope of medical insurance in Shanghai

absorbable surgical suture

surgical suture can be divided into: absorption type - within about a year after implantation, the main body no longer exists at the suture; Non absorbable - after more than a year, it still retains most of its original quality, and partially or completely retains its initial function

the traditional absorbable suture is casing suture. Although it can meet the use requirements, it is not easy to sew and knot, and it is easy to produce antigen/antibody reaction. Its adaptability in vivo is not ideal. Chitin fibers can also be used as sutures, which can be absorbed by tissues after hydrolysis, but the knot strength needs to be improved. Collagen is similar to casing thread in chemical composition. The surgical suture made of collagen has been included in British Pharmacopoeia for ophthalmic surgery

at present, absorbable synthetic suture in foreign countries is mainly composed of PLA, PGA and PGLA

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