Objective To carry out a comprehensive and objective evaluation of viscosupplementation, so as to provide the actual judgments of effectiveness, development trends, and direction. Methods The related l iterature was reviewed, and the keys were the assessments from the international relevant advisory bodies and insurance companies and the evidence-based medicine on cl inic. Results Viscosupplementation has been gradually accepted. Although there are many different cl inical views of the viscosupplementation in the molecular weight of hyaluronan, injection dose, and the indications, intra-articular injection of hyaluronan for the treatment of osteoarthritis is well accepted. ConclusionViscosupplementation is one of the methods of treating osteoarthritis. As it has been already verified that hyaluronan iseffective in treating osteoarthritis of the knee and the periarthritis of shoulder, the hip joint injection is gradually recognized,and other small joints are going gradually.
【Abstract】 Objective To broaden the cl inical uses of fibrin-based biomaterials and to develop further study incell biology and to comprehensively understand and master related knowledge with regard to the present development status of fibrin. Methods Many relevant domestic and international papers were reviewed to make a summary. Results Recognization was obtained from four aspects, which were structure and function of fibrinogen, cl inical use of fibrin, fibrin scaffold for tissue engineering, and compounding biomaterials of fibrin. It showed that every aspect had great research extension and practical appl ication. Conclusion Besides a surgical hemostat and sealant, fibrin has great potentials in playing roles of tissue engineering scaffold, drug del ivery vehicle, and compounding material.
Objective To review the current situation of alginate-based biomedical materials, especially focus on the clinical strategies and research progress in the clinical applications and point out several key issues that should be concerned about. Methods Based on extensive investigation of domestic and foreign alginate-based biomedical materials research and related patent, literature, and medicine producted, the paper presented the comprehensive analysis of its research and development, application status, and then put forward several new research directions which should be focused on. Results Alginate-based biomedical materials have been widely used in clinical field with a number of patients, but mainly in the fields of wound dressings and dental impression. Heart failure treatment, embolization, tissue engineering, and stem cells culture are expected to become new directions of research and products development. Conclusion Development of alginate-based new products has good clinical feasibility and necessity, but a lot of applied basic researches should be carried out in the further investigations.
Objective To compare product standards of drug and medical device made from sodium alginate and calcium alginate between domestic and abroad, and to emphases on the process parameters monitoring based on different standards. Methods Sodium alginate and calcium alginate standards of both domestic and foreign were analyzed and summarized, and the differences and commonalities of various product standards among each standard were compared. Results Differences exist in product standards of sodium alginate and calcium alginate between domestic and abroad, whether drug or medical device, but the fundamental control points are concordant. Conclusion Companies should focus on product quality control requirements combined with its own unique manufacturing process characteristics to develop reasonable and controllable quality standards, which can ensure safe and effective clinical use.
Objective To analyze and compare the domestic quality standard and foreign quality standard of sodium hyaluronate (HA), and to expatiate on the critical process monitoring parameters. Methods Different quality standards of HA were compared by translating and sorting, and some experimental data were analyzed as well as the manufacturing practice was elaborated. Results Differences exist in raw materials standard or specifications of products between domestic and foreign, but the basic control points are concordant. Conclusion The company should set up reasonable and controllable quality standard based on quality requirements and related process characteristics so as to assure the safety and effectiveness of the clinical application.
Objective To review and analyze the properties, products, and appl ications of chitosan so as to explore the key molecular structure parameters which can affect the properties and appl ications significantly, and to reveal the relationship between molecular structures and properties so as to provide reference for further development of chitosan industryand scientific research. Methods Based on the collection and analysis of related l iterature, patents and medical productsderived from chitosan, as well as the author’s experiences in research and development, evaluation and standardization of chitosan, the paper was prepared to bring more attentions into the correlativity between structure and properties of chitosan. Results Potential risks in cl inical appl ication of chitosan-based preparations were seriously proposed in addition to a scientific review and analysis on relationships between chitosan structure and properties, as well as the present situations of developments and appl ications of chitosan. Conclusion The molecular structure is the crucial factor that can bring not only positive but also passive effects to the properties and appl ications of chitosan, especially for highly purified chitosan, molecular weight, and deacetylation degree are the most important parameters that should be focused more attention on.
Objective To verify the technics of inactivating/removing pathogens in medical chitosan derived from shrimp shell. Methods Possible pathogen species were included according to the raw material of shrimp shell used in production, then bacillus cereus, porcine parvovirus (PPV) and pseudorabies virus (PRV) were selected as indicator pathogens.Pathogen solution was prepared in accordance with Technical Standard for Disinfection. The processing procedure of medical chitosan was analyzed to determine whether the alkal ization of chitin and the filter steril ization of chitosan were capable of inactivating/removing pathogens and their efficiencies were tested. Results Bacillus cereus was removed by 8 184 cfu/ mL after alkal ization and 30 818 cfu/mL after filter steril ization. The average logarithm inactivation value (LIV) of PPV and PRV after alkal ization were equal to or above 4.76 logTCID50/0.1 mL and 6.67 logTCID50/0.1 mL, respectively, and their average LIV after filter steril ization were 2.25 logTCID50/0.1 mL and 3.04 logTCID50/0.1 mL. The alkal ization of chitin inactivated/removed indicator pathogens effectively, while the filter steril ization of chitosan removed bacterial effectually but could not inactivate viruses completely. Conclusion The alkal ization of chitin can be used as the technics of inactivating/removing pathogens during the preparation process of medical chitosan to guarantee the safety of the product.
To develop a novel biodegradable collagen-chitosan-[poly(vinyl alcohol), PVA] composite artificial lacrimal canal iculus for treating tear overflowing (epiphora) caused by canal icular obstruction. Methods Homogeneously mixing solution composed of collagen, chitosan and PVA with different ratios was prepared. After several cycles of freezing/thawing process, the mixing solution was transferred into elastic hydrogel. Then the hydrogel was rinsed, punctured, dehydrated and trimmed, and three groups (T1, T2 and T3) of novel artificial lacrimal canal iculus were obtained. The appearance and diameter of all samples were observed under optical microscopy. The cross-section before and after drying as well as phase distribution of sample T2 was observed by SEM. The water absorption ratio and expanding ratio in PBS solution were calculated from three swell ing behavior curves. The degradabil ity of groups T1, T2 and T3 were prel iminary analyzed by degradation experiment in vitro. Results The micro-tubes with 0.5-0.7 mm in inner diameter, 0.9-1.5 mm in outer diameter and more than 20 mm in length were fabricated successfully through physical crossl inking without addition of toxic cross-l inker. SEM result showed that the sample had uniform phase distribution and smooth surface at dried state as well as interpenetrate network structure at hydrogel state. It was seen from the swell ing behavior curves that groups T1, T2 and T3 swelled rapidly within 10-30 minutes, and formed elastic composite hydrogel pipes. In addition, the expanding ratio of inner and outer diameter of the tube was 20%-30% and 100%-120% with swell ing, respectively. The equil ibrium water content of the hydrogel pipes increased with increase of collagen composition. Three groups of samples were immerged in PBS solution contained 2 mg/mL lysozyme at 37 for 1 month, their nozzle cracked, their wall became thin and more transparent. And also, there was small floc deposited on the tube surface. The samples were degraded into mash after they were soaked in PBS solution at 70 for 2 days. Conclusion The novel artificial lacrimal canal iculus with good mechanical property and high water absorption is in favor of operation, tear passing and anti-conglutination. It will be a potential candidate for treating the lacrimal passage occlusion.
Objective To prepare carboxymethylchitin and study its properties. Methods Chitin was prepared from fresh shrimp shells and then carboxymethylchitin was prepared by the methods of alkalization and etherification as well as by the purification technique. The deacetylation degree of carboxymethylchitin was determined by the doublejump potentiometric titration method; the substitution degree was determined by the element analysis method; the carboxymethyl substitution position was analyzed by the Fourier transform infrared spectroscopy apparatus and the nuclear magnetic resonance spectroscopy apparatus; the relative molecular weight and its polydispersity were determined by the gel permeation chromatography with the multiple angle laser light scattering detection; the biological properties were tested according to the GB/T 16886 biological evaluation on medical devices. Results Carboxymethylchitin could be prepared by alkalization and etherification from chitin which was prepared from fresh shrimp shells by decalcification and deproteinization. The deacetylation degree of carboxymethylchitin was 13.76% according to the doublejump potentiometric titration; the degrees of deacetylation and substitution were 14.53% and 1.239 0 respectively according to the element analysis. The IR spectrum showed that the substitutive position was N,O-substitution, and the 13C-NMR spectrum showed that substitutive position of carboxymethylchitin was mostly primary substitution of 6-OH, and according to the substitutive proportion, the substitutive turns were in the following decreasing order: 6-OH, NH2, and 3-OH. The weightaveraged and the numberaveraged molecular weights and polydispersity were 6.25×105, 5.60×105 and 1.22, respectively. The results from the biological property test showed that carboxymethylchitin was a biomaterial that was sterile, pyrogen-free, acute toxicity-free, cytotoxicity-free, intracutaneous irritationfree, skin sensitization-free and biomaterial genotoxicity-free, with no side or adverse effects on the related tissues after implantation into the human body. Conclusion Carboxymethylchitin prepared from chitin by alkalization and etherification is amacromolecule biomaterial that has a low degree of deacetylation, a high degreeof substitution, and a good biocompatibility.
Objective To investigate the latest development of tissue engineeredregenerative medicine in industrialization, with the intention to direct work in practical area. Methods A complete insight of regenerative medicine in industrialization was obtained through referring to update publications, visiting related websites, as well as learning from practical experience. Results The aerial view of the future of regenerative medicine was got based on knowledge of four different tissue engineering projects. Conclusion All present efforts should be devoted to regenerative medicine area meeting the industrialized trends.