聚乳酸-羟基乙酸编织网/胶原-壳聚糖真皮替代物的设计及生物学性能初步评价

目的 设计并构建一种含有编织网的连续性真皮再生模板,并初步评价其生物学性能.方法 采用冷冻-冻干法将聚乳酸-羟基乙酸(PLGA)编织网整合到胶原-壳聚糖支架(CCS)中,形成PLGA编织网/胶原-壳聚糖复合支架(PCCS),对比PLGA编织网、PCCS、CCS微观形态及机械强度.将PCCS及CCS分别埋植于18只SD大鼠皮下(PCCS组、CCS组,每组9只大鼠).术后1、2、4周取埋植部位皮肤标本,行组织形态学观察及免疫组织化学观察(用CD68抗体对巨噬细胞染色),蛋白质印迹法检测CD68、髓过氧化物酶(MPO)、IL-1β、IL-10的蛋白含量.对数据行单因素方差分析和t检验.结果 含有编织网的PCCS具有类似CCS的三维多孔结构;PLGA编织网与PCCS的机械强度分别为(3.07±0.10)、(3.26±0.15)MPa,明显优于CCS[(0.42±0.21)MPa,F=592.3,P＜0.0001].PCCS组约在术后2周完成全层组织长入,CCS组于术后4周才实现这一过程.PCCS组、CCS组均出现巨噬细胞聚集的现象,在术后2周达到高峰,且CCS组可见更多数量的巨噬细胞浸润.术后2周,PCCS组IL-10蛋白含量高于CCS组,而CD68、MPO、IL-1β蛋白含量则低于CCS组(t=-4.06～2.89,P＜0.05或P＜0.01).结论 支架的三维结构与机械强度之间的相互作用,在诱导组织再生中非常重要.PCCS连续性真皮再生模板具有优良的机械性能,合适的三维多孔结构和快速诱导组织、细胞及血管长人的潜能,作为真皮替代物具有一定应用前景.

Abstract：

Objective To design and construct a kind of dermal regeneration template with mesh,and to preliminarily evaluate its biological characteristics. Methods PLGA mesh was integrated into CCS with freeze-drying method for constructing PLGA mesh/CCS composite (PCCS). The micromorphologies and mechanical properties among PLGA mesh, CCS, and PCCS were compared. PCCS and CCS was respectively implanted into subcutaneous tissue of SD rats(PCCS and CCS groups, 9 rats in each group). The tissue samples were collected at post operation week (POW) 1, 2, and 4 for histopathological and immunohistochemical observation. Protein levels of CD68, MPO, IL-1 β, IL-10 were examined by Western blot, with expression of gray value. Data were processed with one-way analysis of variance and t test. Results Threedimensional porous structure of PCCS was similar to that of CCS. Mechanical property of PLGA mesh and PCCS was respectively (3.07 ±0. 10), (3.26 ±0. 15) MPa, and they were higher than that of CCS [(0.42 ±0.21) MPa, F = 592.3, P ＜ 0. 0001)]. The scaffolds were filled with newly formed tissue in PCCS group at POW 2, while those in CCS group were observed at POW 4. A large accumulation of macrophages was observed in both groups, especially at POW 2, and more macrophage infiltration was observed in CCS group. The protein level of IL-10 in PCCS group at POW 2 was obviously higher than that in CCS group, while the protein levels of CD68, MPO, IL-1 β were significantly decreased as compared with those in CCSgroup (with t value from -4.06to2.89,P ＜0.05orP ＜0.01). Conclusions PCCS has excellent mechanical property with appropriate three-dimensional porous structure. Meanwhile, it can rapidly induce formation of new tissue and vascularization, and it has a prospect of serving as a dermal substitute.

Design and biological evaluation of poly-lactic-co-glycolic acid(PLGA) mesh/collagen-chitosan hybrid scaffold (CCS) as a dermal substitute

Objective To design and construct a kind of dermal regeneration template with mesh,and to preliminarily evaluate its biological characteristics. Methods PLGA mesh was integrated into CCS with freeze-drying method for constructing PLGA mesh/CCS composite (PCCS). The micromorphologies and mechanical properties among PLGA mesh, CCS, and PCCS were compared. PCCS and CCS was respectively implanted into subcutaneous tissue of SD rats(PCCS and CCS groups, 9 rats in each group). The tissue samples were collected at post operation week (POW) 1, 2, and 4 for histopathological and immunohistochemical observation. Protein levels of CD68, MPO, IL-1 β, IL-10 were examined by Western blot, with expression of gray value. Data were processed with one-way analysis of variance and t test. Results Threedimensional porous structure of PCCS was similar to that of CCS. Mechanical property of PLGA mesh and PCCS was respectively (3.07 ±0. 10), (3.26 ±0. 15) MPa, and they were higher than that of CCS [(0.42 ±0.21) MPa, F = 592.3, P ＜ 0. 0001)]. The scaffolds were filled with newly formed tissue in PCCS group at POW 2, while those in CCS group were observed at POW 4. A large accumulation of macrophages was observed in both groups, especially at POW 2, and more macrophage infiltration was observed in CCS group. The protein level of IL-10 in PCCS group at POW 2 was obviously higher than that in CCS group, while the protein levels of CD68, MPO, IL-1 β were significantly decreased as compared with those in CCSgroup (with t value from -4.06to2.89,P ＜0.05orP ＜0.01). Conclusions PCCS has excellent mechanical property with appropriate three-dimensional porous structure. Meanwhile, it can rapidly induce formation of new tissue and vascularization, and it has a prospect of serving as a dermal substitute.