明胶改性壳聚糖纤维表征及其体内降解特点

Characteristics and in vivo biodegradation of chitosan fibers modified with gelatin

目的:采用明胶处理壳聚糖纤维,考察其表征及在大鼠肌袋内的生物相容性。方法:实验于2006-09/2007-01在解放军第八十九医院全军创伤骨科研究所实验室完成。①实验分组:分别以磷酸盐缓冲液、50,100g/L明胶处理壳聚糖纤维。②实验评估:测定壳聚糖纤维膨胀率、拉伸强度;扫描电镜、红外光谱观察壳聚糖纤维的形态及结构;分离大鼠脊柱两侧椎旁肌肉形成3个肌袋,分别植入经γ射线灭菌的3种纤维20mg。术后1周,1,3个月将纤维连同包膜完整取出,计算体内降解率。另取标本连同周围肌肉行苏木精-伊红染色。结果:①壳聚糖纤维的膨胀率及拉伸强度:磷酸盐缓冲液组纤维膨胀率最高,拉伸强度最小;100g/L明胶组膨胀率最低,拉伸强度最大。100g/L明胶组拉伸强度与磷酸盐缓冲液组和50g/L明胶组间差异有显著性意义(P<0.05),3组壳聚糖纤维膨胀率差异无显著性意义。②壳聚糖纤维的形态和结构:扫描电镜下磷酸盐缓冲液组纤维束交织,结构略显松散,50、100g/L明胶改性后纤维结构更为致密。红外光谱分析显示明胶和壳聚糖间有相互作用。③体内降解率:磷酸盐缓冲液组体内平均降解率65%,50,100g/L明胶组平均降解率分别为78%和81%,3组间差异无显著性意义。④壳聚糖纤维植入肌袋后的组织相容性:改性后壳聚糖纤维植入后与大鼠周围肌肉连接紧密,表面包膜薄,细胞主要为淋巴细胞,植入12周后3组纤维大部分吸收。结论:明胶改性可进一步提高壳聚糖纤维的强度和生物相容性。

AIM： To determine the characteristics of chitosan fibers modified with gelatin and their biocompatibility in intramuscular sacks of rats. METHODS： The study was carried out in the Military Institute of Traumatic Orthopaedics, the 89 Hospital of Chinese PLA from September 2006 to January 2007.①Grouping： Chitosan fibers were immersed into phosphate buffered saline （PBS）, 50 g/L and 100 g/L gelatin respectively. ②Evaluation： The degrees of swelling and tensile strength were measured, scanning electron microscopy and Fourier transform infrared spectroscopy were used to observe the morphology and structure of chitosan fibers. Furthermore, three kinds of chitosan fibers sterilized by gamma irradiation, each weighed 20 mg, were implanted respectively in three intramuscular sacks beside vertebra in rats. The degree of in vivo biodegradation was calculated by taking out the fibers with their envelopes after 1 week, 1 month and 3 months. Meanwhile, samples with their surrounding muscle were stained by Hematoxylin-eosin. RESULTS： ①The degree of swelling and tensile strength： The degree of swelling in PBS group was maximum and the tensile strength was minimum. While the degree of swelling in the 100 g/L gelatin group was minimum and the tensile strength was maximum. In comparison to the tensile strength, there were significant differences between 100 g/L gelatin group and PBS group, between 100 g/L gelatin group and 50 g/L gelatin group （P 〈 0.05）. However, there was no difference among three groups in the degree of swelling.②The morphological and structural analysis： Scanning electron microscopy observation showed the PBS group had a loose and smooth surface with interlaced fibers. The modified fibers became more compact. There was an interaction between gelatin and chitosan by Fourier transform infrared spectroscopy. ③The degree of in vivo biodegradation： The average degree of biodegradation was 65% in PBS group, 78% in 50 g/L gelatin group and 81% in 100 g/L gelatin group. There was no difference among them. ④The biocompatibility of implanted intramuscular sacks： The modified chitosan fibers were tightened with their surrounding muscles in rats, and their envelopes were thin. The cells presented mostly were lymphocytes. Most of the three fibers were resorbed 12 weeks postoperatively. CONCLUSION： Gelatin modified chitosan fibers has an improved mechanical property and biocompatibility.