人骨形成蛋白-7成熟肽在大肠杆菌中的高效表达

目的：利用大肠杆菌高效表达人骨形成蛋白-7（human bone morphogenetic protein-7，hBMP-7）成熟肽。方法：将编码hBMP-7成熟肽cDNA的基因片段克隆入受控于PRPL启动子的温控型大肠杆菌表达载体pDH，构建成的重组质粒pDHB-7m以大肠杆菌DH5a为宿主菌进行温度诱导表达。结果：含重组质粒的工程菌经42℃诱导表达后在SDS-聚丙烯酰胺凝胶电泳上显现出一条新蛋白区带，分子量约为16ku，表达量占菌体总蛋白的20％～25％，以包涵体形式存在，经简单纯化处理，得到纯度高于80％的人骨形成蛋白-7成熟肽。结论：hBMP-7成熟肽在大肠杆菌中得到高效表达，为深入研究其生物学活性和临床应用奠定了基础。     

Adjunctive Use of Plasma Rich in Growth Factors for Improving Alveolar Socket Healing: A Systematic Review

PurposeThe purpose of this study was to determine whether the adjunctive use of plasma rich in growth factors in postextraction sites could be beneficial in terms of hard- and soft-tissue healing and patients' comfort.Materials and MethodsAn electronic search was performed on MEDLINE, EMBASE, Scopus, and CENTRAL. Only controlled clinical trials or randomized clinical trials that used plasma rich in growth factors in the test group were included. The primary outcomes were pain assessment, complications, and adverse events. Secondary outcomes were hard-tissue healing, bone remodeling, and soft-tissue healing.ResultsEight comparative studies (5 randomized clinical trials) were included. Four studies had a split-mouth design. Six hundred fourteen teeth were extracted in 338 patients. Only qualitative analysis could be performed. Postoperative pain and the incidence of complications such as alveolar osteitis were consistently lower in the test group. Hard-tissue healing, evaluated by clinical, radiographic, histologic, and histomorphometric techniques, showed significantly better results for the test group in almost all studies. Better epithelialization, keratinized tissue thickness, and healing score were also reported.ConclusionPlasma rich in growth factors may bring advantages in some relevant clinical and radiographic outcomes, such as bone density and soft-tissue healing, after tooth extraction. It could also represent a useful tool for reducing adverse events, complications, and patients' discomfort, although it is still not quantifiable.