骨髓基质干细胞与黄芪-壳聚糖/聚乳酸支架对犬牙周骨缺损再生的影响

Effects of astragalus polysaccharides-chitosan/polylactic acid scaffolds and bone marrow stem cells on repairing supra-alveolar periodontal defects in dogs

目的:探讨以犬骨髓基质干细胞(bone marrow stem cells,BMSCs)为种子细胞、黄芪-壳聚糖/聚乳酸(astragalus polysaccharides-chitosan/polylactic acid,AP-C/PLA)为支架移植对水平型牙周骨缺损再生的影响。方法:分离并诱导培养自体犬BMSCs细胞,与AP-C/PLA、壳聚糖/聚乳酸(chitosan/polylac-ticacid,C/PLA)支架构建组织工程复合物随机植入10只犬双侧下颌第3,4前磨牙水平型牙周骨缺损处,共40个实验牙位,每组10个牙位,共设4组:空白对照组;AP-C/PLA+培养基对照组;C/PLA+BMSCS材料对照组;AP-C/PLA+BMSCS实验组。8周后分别收集牙周标本作组织检查和组织学测量。另取2只犬植入AP-C/PLA+BMSCS,4周后作组织学检查。结果:体外诱导培养的BMSCs表达Ⅰ型胶原和碱性磷酸酶活性(alka linephos phatase,ALP);4周实验组缺损部位均有不规则的新骨形成;第8周时,新骨逐渐成熟,各组均有不同程度的牙周再生:实验组牙槽骨修复高度和修复率[(2.90±0.41)mm,57.46%]明显高于空白对照组[(0.83±0.30)mm,15.68%]、培养基对照组[(1.46±0.55)mm,30.13%]、材料对照组[(2.67±0.26)mm,51.87%](P<0.01,P<0.01,P<0.05)。结论:黄芪多糖具有促进牙周缺损部位骨形成作用,以BMSCs为种子细胞、黄芪-壳聚糖/聚乳酸为支架的组织工程复合物修复水平型牙周骨缺损可获得部分的牙周组织再生。

Objective To explore the effect of astragalus polysaccharides- chitosan / polylactic acid （ AP-C/PLA ） scaffolds and bone marrow stem cells （ BMSCs ） on periodontal regeneration of experimentally horizontal periodontal defects in dogs. Methods Dog BMSCs were isolated from the bone marrow and then cultured in a conditioned medium to be induced for osteogenesis. The expressions of Type I collagen and alkaline phosphatase （ALP） were examined by immunohistochemistry and histochemistry in the induced BMSCs, respectively. The BMSCs were harvested and implanted with astragalus polysaccharides- chitosan/polylactic acid （ AP- C / PLA ） and chitosan/polylactic acid （C/PLA） scaffolds. Horizontal alveolar bone defects （5 mm depth, 2 mm width ） were produced surgically in the buccal side of the mandibular premolar 3 and 4 of the 10 dogs . The defects were randomly repaired with a cell- scaffold construction （ 10 teeth per group ） ： root planning only （ surgi- cal control ） , AP-C/PLA with a conditioned medium（ medium control ） , C/PLA with BMSCs （scaf- folds control） , and AP-C/PLA with BMSCs （ experimental group ） . The dogs were killed at 4 weeks and 8 weeks after the surgery, and block sections of the defects were collected for the histologic and histometric analysis. Results BMSCs induced in vitro exhibited an osteogenic phenotype with expressing Type I collagen and ALP histologically. The bone nodule structure was observed in the experimental group 4 weeks postsurgically. The engineered bone became more mature, similar to the native bone 8 weeks postsurgically. The amount of new bone regeneration and the rate of new bone filling to the defect height of the experimental group were significantly different from those of the surgical control, medium control, and scaffolds control [ （2.90±0.41 ） mm vs （0.83 ±0.30） mm, （1.46±0.55） mm, （2.67±0.26） mm; 57.46% vs 15.68 %,30. 13%,51.87%） ]（P〈 0. 01, P 〈 0. 01 , P 〈 0. 05 ）. Conelusion Astragalus polysaeeharides can promote the new bone formation on the periodontal defects. The technology of tissue engineering with AP-C/PLA scaffolds and induced BMSCs may contribute to the periodontal regeneration.