Coraça Débora Cristina, Duek Eliana Aparaecida R, Padovani Carlos A, Camilli José Angelo
Anatomy Department, Biology Institute, State University of Campinas-UNICAMP, SP, Brazil.
J Mater Sci Mater Med. 2008 Jul;19(7):2699-704. doi: 10.1007/s10856-008-3397-2. Epub 2008 Feb 19.
Natural or synthetic materials may be used to aid tissue repair of fracture or pathologies where there has been a loss of bone mass. Polymeric materials have been widely studied, aiming at their use in orthopaedics and aesthetic plastic surgery. Polymeric biodegradable blends formed from two or more kinds of polymers could present faster degradation rate than homopolymers. The purpose of this work was to compare the biological response of two biomaterials: poly(L: -lactic acid)PLLA and poly(L: -lactic acid)PLLA/poly(ethylene oxide)PEO blend. Forty four-week-old rats were divided into two groups of 20 animals, of which one group received PLLA and the other PLLA/PEO implants. In each of the animals, one of the biomaterials was implanted in the proximal epiphysis of the right tibia. Each group was divided into subgroups of 5 animals, and sacrificed 2, 4, 8 and 16 weeks after surgery, respectively. Samples were then processed for analysis by light microscopy. Newly formed bone was found around both PLLA and PLLA/PEO implants. PLLA/PEO blends had a porous morphology after immersion in a buffer solution and in vivo implantation. The proportion 50/50 PLLA/PEO blend was adequate to promote this porous morphology, which resulted in gradual bone tissue growth into the implant.
天然或合成材料可用于辅助骨折或骨质流失部位的组织修复。聚合物材料已得到广泛研究，旨在用于骨科和美容整形手术。由两种或更多种聚合物形成的聚合物可生物降解共混物的降解速率可能比均聚物更快。这项工作的目的是比较两种生物材料的生物学反应：聚（L-乳酸）（PLLA）和聚（L-乳酸）/聚环氧乙烷（PEO）共混物。将44只4周龄的大鼠分为两组，每组20只动物，其中一组接受PLLA植入，另一组接受PLLA/PEO植入。在每只动物中，将其中一种生物材料植入右胫骨近端骨骺。每组再分为5只动物的亚组，并分别在术后2、4、8和16周处死。然后对样本进行处理以进行光学显微镜分析。在PLLA和PLLA/PEO植入物周围均发现了新形成的骨。PLLA/PEO共混物在浸入缓冲溶液和体内植入后具有多孔形态。50/50的PLLA/PEO共混比例足以促进这种多孔形态，从而导致骨组织逐渐生长到植入物中。
