负载SDF-1的羟基磷灰石纳米带/聚乳酸“双面神”复合膜促进牙周再生的研究

As the key material of guided tissue regeneration, barrier membrane plays important roles in determining the outcome of periodontal regeneration. At present, barrier membrane only has the effect of barrier isolation. The development of barrier membrane with bioactivity has become the hotspot and frontier direction of periodontal regeneration. Our project firstly proposes to construct stromal cell derived factor-1 (SDF-1) loaded hydroxyapatite (HAp) nanobelt/polylactic acid (PLA) Janus membrane for promoting periodontal regeneration by controllable assembly method. This HAp/PLA Janus membrane with two functional sides can act as barrier membrane, recruit stem cells, regulate immune reaction and induce bone formation. The underneath mechanisms involve the following aspects: hydrophobic PLA side acts as a barrier to provide space for effective regeneration; hydrophilic HAp nanobelt side facilitates cell attachment, osteogenic differentiation and participates in bone formation as bone source; the sustained release of SDF-1 recruits stem cells to the defect site in the early stage of wound healing and enhances angiogenesis; both SDF-1 and HAp can stimulate M2 polarization of macrophages, alleviate inflammation and synergistically enhance tissue regeneration. This project aims to explore the effects of this Janus membrane on the proliferation, migration and osteogenic differentiation of periodontal ligament stem cells (PDLSCs); to evaluate the effects of this Janus membrane on the polarization of macrophages and on the host immune response; to investigate the effects of this Janus membrane on stem cells engraftment, immune reaction and periodontal regeneration by creating a rat periodontal defect in vivo. This project will provide a new strategy and a novel combined membrane for periodontal therapy, therefore to optimize periodontal tissue regeneration technique.

屏障膜作为引导组织再生的关键材料，决定着牙周再生效果。但目前的屏障膜主要起阻挡作用，开发具有生物活性的屏障膜是牙周再生研究的前沿方向。本项目首次通过对羟基磷灰石(HAp)与聚乳酸(PLA)进行可控组装，构建负载SDF-1的HAp/PLA“双面神”复合膜，一张膜两个功能面发挥屏障阻挡、干细胞募集、免疫反应调控和骨诱导等作用：疏水性PLA作为屏障维持再生空间；亲水性HAp利于细胞附着，促进成骨分化；缓释的SDF-1募集干细胞、促血管生成；SDF-1和HAp均可调控巨噬细胞向M2型极化，减轻炎症反应，协同促进组织再生。本项目拟通过体外实验探讨复合膜对牙周膜干细胞（PDLSCs）增殖、迁移和成骨分化的影响；对巨噬细胞极化的影响和在免疫反应中作用；将复合膜用于体内牙周创区，探讨对干细胞募集、免疫反应及牙周再生的作用。该项目旨在为牙周病治疗提供新的治疗策略和全新概念的复合屏障膜，从而优化牙周再生技术。

开发具有生物活性的屏障膜在重建和再生颌面部组织缺损中具有重要意义。该项目以此作为切入点，在优化组织工程、促进牙周再生及组织缺损修复方面做出贡献。在该项目的资助下，课题组在Applied materials today, Journal of Leukocyte Biology，ACS Omega, ACS Applied Materials & Interfaces ，Journal of Nanobiotechnology 等杂志上发表论文38篇，均标明NSFC资助号81873716。在该项目的资助下，获得山东省科技进步二等奖、山东医学科技奖一等奖等奖项，获批发明专利4项，培养了泰山学者特聘专家1名及多名优秀研究生和博士生，项目组成员多次参加国内外组织再生及口腔学术会议汇报成果，获得同行专家一致认可与好评，主要内容如下：.（1）基于牙周原位组织工程原理，成功构建了负载SDF-1的HAp/PLA“双面神”复合膜，实现SDF-1的早期快速释放和晚期的缓慢释放。利用SDF-1-HAp面对干细胞募集、免疫调控、促进血管分化、促进成骨作用，及PLA面的屏障阻挡作用，协同多因素高效修复牙周缺损。应用于牙周缺损时，启动宿主修复潜能，动员自身干细胞到达创区，促进早期骨改建，调控巨噬细胞M2型极化，促进新生血管的形成、成骨分化并形成成骨-成血管耦合，进一步提高新生骨质量，为原位牙周组织工程策略进一步临床转化奠定了坚实的基础。.（2）在此基础上，我们还开展了SDF-1与Exendin-4联合应用的研究，证明了二者联合应用在体外能够促进牙周膜干细胞增殖、迁移和成骨分化，体内促进牙周骨组织再生。.（3）研发了时序递控bFGF与BMP-2的核壳结构， DMOG/nSi成血管/成骨耦合双功能膜等生物支架材料，这些材料在体外具有促进细胞成骨分化、成血管分化， 在体内能够募集干细胞归巢、促进血管新生、调控骨免疫，协同促进牙周组织结构和功能上的再生。. 总之，该项目为牙周和骨组织的再生修复探讨了新的治疗策略和生物复合屏障膜，促进了原位牙周组织工程技术在牙周再生治疗中的应用和发展，为临床牙周病及口腔颌面部缺损的治疗奠定理论依据和实验基础。