双交联明胶-壳聚糖复合人工真皮支架的制备及其性能研究

Preparation of gelatin-chitosan composite dermis scaffold with bi-crosslinking system and study on the properties

采用1-乙基-(3-二甲基氨基丙基)碳化二亚胺盐酸盐(EDC.HCl)和三聚磷酸钠(STPP)作为共价-离子双交联剂交联制备了明胶-壳聚糖(gel-CS)复合人工真皮支架。通过FT-IR和SEM对复合多孔支架结构及形貌进行表征,同时对复合多孔支架的孔隙率、平均孔径、溶胀性能和降解性能进行了研究。研究结果表明,明胶和壳聚糖两相间成功地发生了交联反应,形成了具有贯通孔结构和良好孔隙率的复合多孔支架。该支架平均孔径在136.1～182.9μm之间,且随着壳聚糖含量的增加,孔径及孔隙率随之降低;溶胀性能研究发现,相较于单一共价交联方法,采用双交联法制备的支架溶胀率有所降低,再次印证双交联法制备的支架其交联度较单一共价交联的高;酶降解实验表明,固定STPP含量,随着EDC含量增加,复合支架的降解性能越好,而EDC含量一定,则STPP含量为0.5%时,复合支架具有最好的降解性能。

1-ethyl-（3-dimethylaminopropyl） carbodiimide hydrochloride（EDC.HCl） and sodium tripolyphosphate（STPP） as the covalent and ionic bi-crosslinking agents were introduced to prepare gelatin-chitosan（gel-CS） composite porous scaffolds.The structure and morphology of the scaffolds were characterized by Fourier transform infrared spectrometer（FT-IR） and scanning electron microscope（SEM）,and also the porosity,mean pore size,swelling properties and degradation were studied.In addition,the cross-linking mechanism was analyzed.The results show that covalent and ionic cross-linkage have taken place between the two phases of gel and CS in the composite porous scaffolds;these scaffolds have interconnected pores and high porosity,and the mean pore size is in the range of 136.1-182.9μm;the swelling properties of the scaffolds prepared by covalent and ionic bi-crosslinking are better than that of single covalent cross-linking,indicating that the cross-linking degree of covalent and ionic bi-crosslinking is higher than that of single covalent cross-linking.The degradation experiments show that,if STPP is constant,the degradation properties of scaffolds become better with EDC increasing;if EDC is constant,0.5% STPP can produce the scaffold with the best degradation property.