Phage-inspired nanoparticles with genetically tunable target-specificity

修改后的项目摘要/摘要部分： 非病毒基因治疗是治疗心肌缺血的一种很有前途的方法，心肌缺血是一种由于血管堵塞而导致氧气和营养物质供应受阻的方法。血管内皮生长因子(VEGF)可以触发新的血管形成。因此，将携带血管内皮生长因子的间充质干细胞移植到受损心肌组织中，不仅是因为表达的血管内皮生长因子可以诱导新血管的形成，提供所需的氧气和营养，而且还因为骨髓间充质干细胞可以分化为心肌细胞，使受损组织再生，是治疗心肌缺血的基因治疗策略之一。我们的长期目标是将生物分子识别和纳米技术相结合，构建靶向特异性的非病毒纳米载体，将血管内皮生长因子基因转移到心脏，用于治疗心肌缺血。本应用的目的是模拟噬菌体的结构，将噬菌体展示筛选出的靶向多肽与血管内皮生长因子基因捆绑的超顺磁性纳米颗粒组装成噬菌体状纳米颗粒用于血管内皮生长因子基因的传递。本项目的总体假设是，噬菌体展示筛选出能够靶向MSCs的多肽，通过自组装过程将其整合到具有细胞特异性多肽基序的VEGF基因捆绑的超顺磁性纳米颗粒中，所得到的多功能噬菌体样纳米颗粒将具有理想的细胞特异性，并提高VEGF基因转移到MSCs的效率。目的1利用噬菌体展示技术筛选能够特异性内化到MSCs中的多肽。目的2是将细胞靶向多肽与血管内皮生长因子基因捆绑的超顺磁性纳米粒结合，通过自组装构建具有细胞特异性多肽结构的噬菌体纳米粒。目的3是评价纳米粒在外加磁场和不加磁场时的稳定性、细胞毒性、细胞特异性和转染率。该项目的成功完成将有助于开发一种新的基因治疗策略，用于治疗需要表达血管内皮生长因子以诱导新血管形成的疾病。

Modified Project Summary/Abstract Section: Non-viral gene therapy is a promising approach to treating myocardial ischemia where the supply of oxygen and nutrients are blocked due to blockage in the blood vessels. Vascular Endothelial Growth Factor (VEGF) can trigger new blood vessel formation. Thus, one of the gene therapy strategies for treating myocardial ischemia is to graft mesenchymal stem cells (MSCs) with VEGF transfected in damaged heart tissue not only because the expressed VEGF can induce the formation of new blood vessels to supply the required oxygen and nutrients but also because MSCs can differentiate into heart muscle cells and revive the damaged tissue. Our long-term goal is to integrate biomolecular recognition and nanotechnology to build target-specific non-viral nano-vectors that can deliver VEGF gene to heart for treating myocardial ischemia. The objective of this application is to mimic the structure of phage to assemble target-specific peptides selected by phage display and a VEGF gene-tethered superparamagnetic nanoparticle into a phage-like nanoparticle for VEGF gene delivery. The overall hypotheses of this project are that phage display selected peptides that can target MSCs can be integrated into the VEGF gene-tethered superparamagnetic nanoparticles with cell-specific peptide motif protruding from the surface by a self-assembly process and the resultant multi-functional phage-like nanoparticle will have desired cell-specificity and improved efficiency of VEGF gene transfer into MSCs. Aim 1 is to select a peptide that can be specifically internalized into MSCs by using phage display technology. Aim 2 is to integrate cell-targeting peptides into VEGF gene-tethered superparamagnetic nanoparticles to build phage-like nanoparticles with cell-specific peptide motifs protruding from the surface through self-assembly. Aim 3 is to evaluate the stability, cytotoxicity, cell-specificity and transfection efficiency of the nanoparticles with and without an external magnetic field. Successful completion of this project will enable the development of a new gene therapy strategy for treating diseases that require VEGF expression to induce new blood vessel formation.