NANO-PATTERNING OF BIOMATERIALS FOR BLOOD-VESSEL FORMATION IN ARTIFICIAL TISSUES

用于人造组织中血管形成的生物材料纳米图案化

基本信息

批准号：
8484754
负责人：
Patrick Benitez
金额：
$ 3.19万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-06-25 至 2017-06-24
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8484754
关键词：
Actins Adhesions American Analysis of Variance Angiopoietin-1 Animal Model Area Arginine Artificial Organs Aspartic Acid Biocompatible Materials Biology Bioreactors Blood Vessels Cell Culture Techniques Cell physiology Cell-Matrix Junction Cells Chi-Square Tests Chimeric Proteins Clinic Clinical Coculture Techniques Computer Analysis Cytoplasmic Tail Cytoskeletal Modeling DNA Data Development Elastin Endothelial Cells Engineering Enzyme-Linked Immunosorbent Assay Extracellular Matrix Faculty Failure Fibronectins Fluorescence Microscopy Focal Adhesion Kinase 1 Glean Glycine Growth Factor Human Image Analysis Implant In Vitro Integrins Lead Left Length Life Ligands Measures Mechanical Stimulation Mediating Medical Mentors Mesenchymal Metabolic Molecular Organ Organ Transplantation Oxygen Patients Peptide Hydrolases Perfusion Phosphorylation Process Protein Engineering Proteins Radial Recombinants Regenerative Medicine Regression Analysis Research Reverse Transcriptase Polymerase Chain Reaction Signal Transduction Specific qualifier value Speed Staining method Stains Stem cells Structure Surface Talin Technology Testing Thick Tissue Engineering Tissues Training Translating Translations Transplantation Vascular Endothelial Growth Factors Vascularization Work base blebbistatin cell growth cell motility cellular engineering clinically relevant implantation improved in vivo meetings monolayer nano nanofiber nanopattern nanoscale novel polymerization prevent professor receptor regenerative therapy scaffold two-dimensional vector

项目摘要

DESCRIPTION (provided by applicant): Patients suffering from failure of a vital organ can be treated with whole organ transplantation; transplantation alone, however, cannot meet the public's medical needs due to the limited supply of donated organs. Artificial tissues present an alternative to donated organs, but our inability to engineer functional microvessels within such constructs broadly prevents the development of clinically effective artificial tissues. Because all tissue- scale regenerative therapies require perfusion, the ability to form functional microvasculature is paramount. Upon implantation of bulk artificial tissues without microvasculature, cells on the inside die from lack of oxygen, leaving a shell of live cells about 0.2 mm thick. Artificial vascularization will prevent this by creating a volume- spanning perfusion-competent network and by enabling swift vascular integration after implantation. To engineer microvasculature, we propose a novel biomaterials strategy: nanoscale clustering of cell- matrix adhesion ligands. Previous work on 2D surfaces has shown that clustering of ligands increases growth factor sensitivity and motility via receptor clustering. Research using animal models has shown that expression of molecular disruptors of receptor clustering is associated with a decrease in both branching and maturation. Though ligand clustering and receptor clustering are related thermodynamically, it is unknown whether nanoscale ligand clustering will lead to morphologically appropriate microvasculature in a 3D, bulk biomaterial. To answer this question, we have developed a nanofibrous biomaterial that can be fabricated at a specified bulk concentration and nanoscale clustering of adhesion ligands. By mimicking the nanoscale order of the native the extracellular matrix, we expect to achieve organotypic blood-vessel structure formation in vitro. We specifically hypothesize that clustering of adhesion ligands will upregulate three essential cellular process that lead to formation of blood-vessels in vivo: (1) growth factor sensitivity, (2) cell motility, and (3) vessel branching and maturation. Growth factor sensitivity will be assessed by measuring proliferation, metabolic activity, and protease secretion. Motility, as parameterized by cell speed and persistence length, and cytoskeletal organization will be assessed by quantitative image analysis. Branching and maturation will be assessed by immunostaining for appropriate markers and computational analysis of morphological data. The biomaterials proposed here can be further developed as an implant for regenerative medicine by incorporating non- overlapping technologies such as co-culture of tissue-specific stems cells, growth factor delivery, and bioreactor/ mechanical stimulation. My mentor Sarah Heilshorn, an expert in protein-based materials engineering, and our collaborator John Cooke, a senior professor of microvascular signaling biology, have developed an appropriate training plan to accomplish this project.

描述（申请人提供）：重要器官衰竭的患者可以进行全器官移植治疗；然而，由于捐献器官供应有限，仅靠移植无法满足公众的医疗需求。人造组织提供了捐赠器官的替代方案，但我们无法在此类结构中设计功能性微血管，这在很大程度上阻碍了临床有效人造组织的发展。因为所有组织规模的再生疗法需要灌注，形成功能性微脉管系统的能力至关重要。植入没有微血管的大块人造组织后，内部细胞会因缺氧而死亡，留下约 0.2 毫米厚的活细胞壳。人工血管化将通过创建跨体积的灌注网络并在植入后实现快速血管整合来防止这种情况发生。为了设计微脉管系统，我们提出了一种新颖的生物材料策略：细胞基质粘附配体的纳米级聚集。先前对 2D 表面的研究表明，配体簇通过受体簇增加了生长因子的敏感性和运动性。使用动物模型的研究表明，受体簇分子干扰物的表达与分支和成熟的减少有关。尽管配体簇和受体簇在热力学上相关，但尚不清楚纳米级配体簇是否会在 3D 块状生物材料中产生形态上合适的微脉管系统。为了回答这个问题，我们开发了一种纳米纤维生物材料，可以以指定的体积浓度和粘附配体的纳米级聚集来制造。通过模仿天然细胞外基质的纳米级顺序，我们期望在体外实现器官型血管结构的形成。我们特别假设粘附配体的聚集将上调三个重要的细胞过程，从而导致血管形成体内：(1) 生长因子敏感性，(2) 细胞运动性，(3) 血管分支和成熟。通过测量增殖、代谢活性和蛋白酶分泌来评估生长因子敏感性。由细胞速度和持久长度参数化的运动性以及细胞骨架组织将通过定量图像分析进行评估。将通过适当标记的免疫染色和形态学数据的计算分析来评估分支和成熟。这里提出的生物材料可以通过结合非重叠技术（例如组织特异性干细胞的共培养、生长因子递送和生物反应器/机械刺激）进一步开发为再生医学的植入物。我的导师 Sarah Heilshorn（蛋白质材料工程专家）和我们的合作者 John Cooke（微血管信号生物学高级教授）制定了适当的培训计划来完成这个项目。