Biocompatibility of new absorbable material:nano-composite of poly (L-lactide) and surface grafted hydroxyapatite / 吉林大学学报(医学版)

ABSTRACT

Objective To make a comprehensive evaluation of nano-composite of poly(L-lactide) and surface grafted hydroxyapatite(PLLA/PLLA-gHA) as a new material.Methods According to the evaluated critera of medical implanted materials biology and animal trial recommended in GB/T 16886 and IS0 10993 criterion,the new material was carried out on acute systemic toxicity test,haemolysis test,muscular implantation test and subcutaneous injection test.The extract liquid of new material was injected into mice by vena caudalis to test common station,toxic reaction of it at different time,the results were used to evaluate the acute systemic toxicity.Fresh anticoagulant cony blood was mixed with extract liquid of new material with density of 100 g?L-1 to measure each absorbance with spectrophotometer and work out the corresponding rate of haemolysis.The red punctuation and hydropsia of rabbits were observed at different time by subcuntaneous injecting extract liquid into the back of rabbits.PLLA/PLLA-gHA composite plates were implanted into the sacrospinal muscle of rabbits.Cony venous blood was extracted to detect indicatrix of hematology at diferrent time.The material and surrounded tissues were taken out from animals at the 14th,30th,60th,90th,180th,360th day to examine anatomic and pathological changes.Results Rabbits with PLLA/PLLA-gHA composite had good general condition.There was no any acute systemic toxicity in vivo.Data of AST and Scr had no significant difference between experimental group and control group.The hemolysis rate of extrac liquid was 1.22%,which was under the standard criteria(5%).No red punctuation and light hydropsia were observed at different time in the subcutaneous injection test.The inflammation cytochange of PLLA/PLLA-gHA composite group was similar with that of control group in early days,which was met with the general regularity of inflammatory outcome.The fibrosis membrane surrounding the PLLA/PLLA-gHA composite became thinner gradually with the elongation of implantation time.The fibrosis membrane grew into the material at the 360th day.The degree of the fibrosis membrane was below class Ⅰ.Conclusion The new absorbable type PLLA/PLLA-gHA composite has excellent biocompatibility and security.