壳聚糖I型胶原明胶复合材料的生物相容性及神经修复作用精.docx

1、壳聚糖I型胶原明胶复合材料的生物相容性及神经修复作用精NEURAL REGENERATION RESEARCH Volume 7, Issue 15, May 2012Cite this article as: Neural Regen Res. 2012;7(15):1179-1184.www.nrronline.orgEffect of chitosan/type I collagen/gelatin composites in biocompatibility and nerve repair*Qing Wang1, Xiaolei Yang2, Ming Ren2, Yulin Hu3

2、, Qiang Chen2, Lei Xing2, Chunyang Meng2, Tiemei Liu11China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China2Department of Toxicology, School of Public Health, Jilin University, Changchun 130021, Jilin Province, China3Department of Liver, Gall and Pancreas, First Hospi

3、tal of Jilin University, Changchun 130021, Jilin Province, ChinaAbstractChitosan, collagen I and gelatin were mixed in appropriate quantities to develop a new nerve repair material, with good arrangement and structure, as well as even aperture size. The compositematerial was sterilized by 60Co irrad

4、iation for 24 hours prior to implantation in the right thigh of rats following sciatic nerve damage. Results showed that the material was nontoxic to the kidneys and the liver, and did not induce an inflammatory response in the muscles. The composite material enhanced the recovery of sciatic nerve d

5、amage in rats. These experimental findings indicate that the composite material offers good biocompatibility and has a positive effect on injured nerve rehabilitation.Qing Wang, M.D., Professor, China-Japan Union Hospital, Jilin University, Changchun130033, Jilin Province, ChinaCorresponding author:

6、Tiemei Liu, M.D., Professor, China-Japan Union Hospital, Jilin University, Changchun130033, Jilin Province, China liutiemei777Received: 2012-02-03 Accepted: 2012-04-24 (N20111015003/WLM)Wang Q, Yang XL, Ren M, Hu YL, Chen Q, Xing L, Meng CY, Liu TM. Effect of chitosan/type I collagen/ gelatin compos

7、ites inbiocompatibility and nerve repair. Neural Regen Res. 2012;7(15):1179-1184.www.nrronline.orgdoi:10.3969/j.issn.1673-5374.2012.15.009Key Wordschitosan; collagen I; gelatin; biomaterials; biocompatibility; nerve repair; neural regenerationcartilage, bone and nerve tissue repair13. Gelatin is bio

8、degradable; however, it is a brittle substance, absorbs water well and expands. The combination of gelatin and chitosan can compensate for the deficiencies in each of these twocompounds. Type I collagen is the most abundant of all the collagen proteins that undergoes natural degradation in the body.

9、 Collagen has been widely used for drug delivery systems, particularly in burn repair, as it provides a supporting structure for cells. Collagen may enhance the affinity of chitosan to nerve cells14. Published papers have used combinations of chitosan and gelatin, chitosan andcollagen, or gelatin an

10、d collagen for nerve or tissue repair15-17.However, there is currently no research using the combination of chitosan, gelatin and collagen I in nerve repair. Thus, the aim of this study is to explore thebiocompatibility and nerve repair potential ofINTRODUCTIONNerve damage is commonplace in clinics

11、due to accidents and injuries1. However, mature nerve cells have a limited capacity for regeneration. Injured nerves will trigger various functional disturbances to the body if they are not repaired in a timely manner. An ideal nerve repair material should bebiocompatible, biodegradable and enhance

12、nerve function rehabilitation.Chitosan is a polysaccharide with great biocompatibility and biodegradability that facilitates tissue regeneration; thus, it has been widely used for nerve repair. However, chitosan has a crispy texture that makes it difficult to suture to the host tissues, and the abso

13、rption of chitosan is slow, which affects its efficacy as a treatment strategy2-12. Gelatin, on the other hand, is a constituent of bones, tendons, and connective tissues of animals, and is widely used in clinics for skin,1179Wang Q, et al. / Neural Regeneration Research. 2012;7(15):1179-1184.a chit

14、osan/gelatin/collagen I biomaterial.RESULTSQuantitative analysis of experimental animalsA total of 156 rats were included in this study: 96 rats were used to determine the biocompatibility of thecomposite, and 60 rats were examined for nerve repair. For each experiment, the rats were equally divided

15、 into three groups: control (uninjured), injury (injured only) and materials (injured and treated with material placement). Overall, 156 rats were involved in the results analysis.Ultrastructure of chitosan-collagen I-gelatin compositeThe structure of the nerve repair material was cylindrical and un

16、iform, with good flexibility and strong elasticity. The microstructure of the transverse, longitudinal and diagonal sections of the sterilized material under a scanning electronic microscope showed that the outer structure of the material was fully enclosed. The inner structure showed a uniform aper

17、ture, with parallelmicrotubules travelling uniformly. The structure was not affected by pore size, and the trabecular wall of the pores had good continuity, smooth surfaces, and no folds; the outer surface was imbricated. The longitudinal orientation of the microtubules was independent of each other

18、 and in a closed state. There were no exchanges for the bridge connecting pipes and the overall structure was irregular, with an inconsistent diameter. The transverse sections of the material were predominantly circular, with a regular shape and uniform diameter (Figure 1). The internal structure of

19、 the material was also regular, and the ideal microstructure was conducive to the regeneration of fiber-oriented growth. The basic direction of themicrotubules was parallel and independent, with a uniform diameter. These structures helped the anatomical and functional reconstruction of the nerve aft

20、er injury.The biocompatibility of chitosan/collagen I/gelatin compositeAfter surgery, the activity level for the rats in the injury and material groups reduced significantly. The footattached to the operated limb was lame, yet there was no notable inflammatory reaction or self-mutilation. On day 2 a

21、fter surgery, the operated muscle cicatrized well. At days 3, 7, 14, 21 after surgery, we noted no obvious changes to the embedded material.Gross and histological changes of liver, kidney and musclesUnder a light microscope, the structures of the liver and1180the kidneys in the rats from the three g

22、roups were similar, and no abnormal changes were found. In the leftquadriceps femoris muscles of rats in the materials group, numerous inflammatory cells had infiltrated around the material on days 3 and 7. Furthermore, the material had been subjected to phagocytosis, degraded and a foreign granulom

23、a had formed. An inflammatory response was also seen in the rats of the injury group. On days 14 and 21, the inflammatory response in the thigh muscles of rats from the material group had disappeared, but the foreign granuloma was still visible. For rats in the injury group, the inflammation had als

24、o disappeared, similar to that seen in the rats in the control group (Figure 2). There was no significant difference in the organ:body weight ratio in rats among these three groups (P 0.05; Table 1).Figure 1 Surface sections of the repair materials under electron microscopy.(A) Longitudinal section

25、of the material showed anirregular shape and an inconsistent diameter ( 150).(B) Transverse section of the material showed that theinternal structure was regular ( 601).(C) Transverse section of the material showed thetrabecular walls of the pores had good continuity ( 1 201). (D) Transverse section

26、 of the material showed the surface was smooth, with no folds ( 2 403).Changes of blood routine and biochemical indicators in ratsThere were no significant differences in the peripheral hemoglobin and the level of blood urine nitrogen and urine creatine from rats among the three groups (P 0.05). On

27、days 3 and 7 after injury, the number ofperipheral white blood cells in rats from the material and injury groups was significantly higher than that from the control group (P 0.05). By day 14, the number ofperipheral white blood cells decreased to normal levels. The changes in glutamic oxaloacetic tr

28、ansaminase, glutamic pyruvic transaminase, lactate dehydrogenase and creatine kinase levels from day 3 to day 21 are shown in Tables 2-5.Wang Q, et al. / Neural Regeneration Research. 2012;7(15):1179-1184.Liver (100) Kidney (100) Muscle (200)pu org lor ntoC p u o) rgs yl aaidr e3( atM p u) osrgy a y

29、dr u3j( nI p uo)r gs ylaa idr e7( atM p u)os rgy aydr u7j(nI p uo) sr gy aladir4 e1(atMp u)osryga yd ru4j1n(Ipu o)rsgylaadi r e12at( Mpu)osry ga yd r u1j2n(I Figure 2 Hematoxylin-eosin stained sections. Morphology changes in the liver, kidneys and muscles were determined using light microscopy.There

30、 were no changes in liver and kidneys in rats from the three groups. In the thigh muscles, numerous inflammatory cells had infiltrated after surgery in the materials and injury groups. By days 14 and 21, the inflammation haddisappeared, but foreign granuloma could still be observedin the materials g

31、roup.1181Wang Q, et al. / Neural Regeneration Research. 2012;7(15):1179-1184.Chitosan/collagen I/gelatin composite promotes the functional rehabilitation of sciatic nerveOn day 45 after surgery, a muscular electromyogram showed that the injured nerve in the material grouprecovered from the lesion qu

32、icker than the nerves in the injury group (P 0.01; Table 6).1182DISCUSSIONNerve injury is very common clinically. When nerve injury is severe and the nerve function is lost, the patient often exhibits a series of functional disturbances in other parts of the body, which is sometimes puzzling for clinicians. As such, nerve repair has attracted a lot of attentionwithin the medical profession. Various tissue engineering methods