膜性高分子材料在兔眼部的生物相容性

目的评价聚羟基脂肪酸(polyhydroxyalkanoates,PHA)、聚乳酸(polylacetic acid,PLA)和聚己内酯(polycaprolactone,PCL)三种膜性高分子材料在兔眼部的生物相容性。方法将24只新西兰兔随机分为4组,每组6只。PHA、PLA、PCL为实验组,材料植入兔右眼结膜下。假手术组结膜下钝性分离,但不植入任何高分子材料。使用裂隙灯显微镜观察并记录植入后不同时间手术眼的反应并评分。裂隙灯下观察材料的吸收时间。术后4周和16周取眼球,行HE染色、Masson染色和天狼猩红染色分别定性观察组织结构和炎症细胞、胶原纤维和胶原纤维的亚型与排列方向。结果术眼刺激性评分等级各组均不高于"轻度刺激性"。结膜下吸收时间PHA、PLA和PCL组分别是16周,12周和大于16周。组织学观察术后4周PHA、PLA和PCL组均形成材料包裹囊腔,囊壁以纤维组织为主,伴有毛细血管形成和炎性细胞浸润,以中性粒细胞为主。胶原纤维染色与假手术组无明显差异,以Ⅰ型和Ⅲ型为主,大致呈平行排列。术后16周PHA和PLA组材料已不可查及,包裹囊腔结构不规则,而PCL材料整体可查及,包裹囊腔规则。各组未见毛细血管,偶见淋巴细胞浸润。胶原纤维与假手术组无明显差异,以Ⅰ型和Ⅲ型为主,仍大致呈平行排列。结论 PHA、PLA和PCL三种膜性高分子材料在兔眼具有较好的生物相容性,结膜下吸收时间分别是16周,12周和大于16周。

Biocompatibility of membranous polymers in rabbit eyes

Objective To investigate the biocompatibility of three membranous polymers,polyhydroxyalkanoates（PHA）,polylacetic acid（PLA） and poly-ε-caprolactone（PCL） in the rabbit eyes.Methods Twenty four healthy New Zealand white rabbits were randomly divided into 4 groups,with 6 rabbits each.PHA,PLA and PCL polymers were implanted into subconjunctival space of the right eyes in rabbits.The sham-operation group underwent subconjunctival space blunt dissection,without polymers implantation.The reactions of the operated eyes at different time-points were scored according to the Experimental Eye Irritation criteria under slit lamp microscope.Absorption time of the polymers was also recorded.The eyeballs were enucleated at 4 weeks and 16 weeks after implantation,HE staining,Masson staining and Sirius red staining were used to examine the tissue structure and inflammatory cells,collagen and collagen fiber subtypes,respectively.Results Irritation scores of all experimental groups were less than the level of ＂mild irritant＂.The absorption time of PHA,PLA and PCL groups were 16 weeks,12 weeks and longer than16 weeks,respectively.Histological study revealed that,4 weeks after the implantation,a capsule was formed around the implanted membrane by fibroblasts and collagen fibers.Few capillaries and inflammation cells,neutrophils were also observed.The subtypes of collagen fibers showed no significant difference among groups.Sixteen weeks after the implantation,no PHA and PLA membranes could be observed at the implanted site,leaving an irregular cavity.PCL membrane was still present in situ.Capillaries were rare and a few lymphocytes were present.Conclusions Membranous PHA,PLA and PCL polymers show good biocompatibility in rabbit eyes,and their absorption time is 16 weeks,12 weeks and longer than 16 weeks,respectively.