Bone-seeking and cell-targeting non-viral vectors for BMP-2 gene delivery

描述（由申请人提供）： 基因治疗已成为骨修复和再生的一种有前途的策略。其成功的关键是将感兴趣的基因递送到目标骨折部位，并以合适的水平表达。已经提出了离体和体内基因治疗策略。在离体策略中，从患者收获靶细胞如间充质干细胞（MSC），在体外条件下将载体携带的感兴趣的基因如骨形态发生蛋白（BMP）基因递送至靶细胞，然后将靶细胞植入损伤部位。在体内策略中，载体携带的目的基因通过静脉内注射递送至靶位点或直接植入至损伤位点。因此，理想的基因传递载体应该是骨导向和细胞靶向的。我们的长期目标是整合自然进化的生物识别和纳米技术，构建靶向特异性的非病毒基因载体，用于基因治疗的骨再生。本申请的目的是形成和评价用于BMP-2基因的病毒样位点特异性递送的骨导向和细胞靶向非病毒载体。该项目的总体假设是，通过基于病毒的选择技术鉴定的寻骨和细胞靶向肽可以与携带BMP-2基因的纳米颗粒生物仿生自组装，以形成用于位点特异性BMP-2基因递送的寻骨和细胞靶向病毒样非病毒载体。本研究的主要目的是：（1）从病毒随机肽库中筛选趋骨和细胞靶向多肽，（2）将BMP-2基因纳米颗粒与趋骨和细胞靶向多肽仿生组装，形成趋骨和细胞靶向非病毒载体;和（3）通过骨导向和细胞靶向非病毒载体的体外BMP-2基因递送的评估。该项目的成功完成将发现一种骨导向和细胞靶向肽，并产生一种新型的非病毒基因递送载体，具有高转染效率和骨细胞/组织特异性。这种载体可用于肌肉骨骼组织的修复和再生，以及通过基因疗法治疗基于遗传的骨疾病如骨生成障碍。

DESCRIPTION (provided by applicant): Gene therapy has emerged as a promising strategy for bone repair and regeneration. The key to its success is to deliver the genes of interest to the target bone fracture site that can be expressed at suitable levels. Both ex vivo and in vivo gene therapy strategies have been proposed. In the ex vivo strategy, target cells such as mesenchymal stem cells (MSCs) are harvested from the patient, genes of interest such as bone morphogenetic protein (BMP) gene carried by a vector are delivered to the target cells under in vitro conditions, and then the target cells are implanted into the site of injury. In the in vivo strategy, genes of interest carried by a vector are delivered to the target site by intravenous injection or directly implanted to the site of injury. Thus an ideal gene delivery vector should be bone-seeking and cell-targeting. Our long-term goal is to integrate the naturally evolved biological recognition and nanotechnology to build target-specific non-viral gene vectors for bone regeneration by gene therapy. The objective of this particular application is to form and evaluate bone-seeking and cell-targeting non-viral vectors for virus-like site-specific delivery of BMP-2 gene. The overall hypothesis of this project is that bone-seeking and cell-targeting peptides identified by a virus-based selection technology can biomimetically self-assemble with the BMP-2 gene-bearing nanoparticles to form bone-seeking and cell-targeting virus-like non-viral vectors for site-specific BMP-2 gene delivery. The following specific aims are designed to test our central hypotheses: (1) Selection of bone-seeking and cell-targeting peptides from a virus-based random peptide library; (2) Biomimetic assembly of BMP-2-gene-bearing nanoparticles and the bone-seeking and cell-targeting peptides to form bone-seeking and cell-targeting non-viral vectors; and (3) Evaluation of in vitro BMP-2 gene delivery by the bone-seeking and cell-targeting non-viral vectors. Successful completion of this project will discover a bone-seeking and cell-targeting peptide and produce a novel non-viral gene delivery vector that exhibits high transfection efficiency and bone cell/tissue-specificity. Such vectors can be used for the repair and regeneration of musculoskeletal tissues and treatment of genetic based bone diseases such as osteogenesis imperfecta by gene therapy.