3D Differentiation of Mesenchymal Stem Cells in Peptide Amphiphile Matrices

肽两亲基质中间充质干细胞的 3D 分化

• 批准号: 8202481
• 负责人: John B Matson
• 金额: $ 4.84万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2012-08-10
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8202481
• 关键词: 3-Dimensional; Adult; Area; Binding; Biological; Bone Development; Bone Growth; Bone Regeneration; Buffers; Cancerous; Cell Culture Techniques; Cells; Circular Dichroism; Defect; Dexamethasone; Dimensions; Electron Microscopy; Excision; Extracellular Matrix; Family; Fatty Acids; Future; Gel; Gene Expression; Growth Factor; Healed; Human; Hydrazones; Hydrolysis; Hydroxyapatites; In Vitro; Injectable; Kinetics; Lead; Malignant Neoplasms; Measures; Mesenchymal Stem Cells; Methods; Minerals; Nanostructures; Natural regeneration; Osteogenesis; Osteoporosis; Pathway interactions; Patients; Peptide Signal Sequences; Peptides; Pharmaceutical Preparations; Play; Production; Proteins; Quality of life; Regenerative Medicine; Reporting; Research; Rheology; Roentgen Rays; Role; Solutions; Staining method; Stains; Time; Trauma; Work; adult stem cell; aging population; analog; aqueous; bone; bone healing; bone morphogenic protein; cell type; controlled release; design; healing; improved; in vitro testing; in vivo; mimetics; nanofiber; novel; osteogenic; osteoporosis with pathological fracture; peptide A; protein aminoacid sequence; protein expression; research study; scaffold; stem cell differentiation; two-dimensional

DESCRIPTION (provided by applicant): New materials that are capable of interacting with adult stem cells to direct their differentiation toward a certain terminal cell type will play an important role in the emerging field of regenerative medicine. The proposed work details a strategy for inducing the differentiation of human mesenchymal stem cells (hMSCs) into osteoblastic lineage inside a three dimensional scaffold, with applications in bone regeneration. The proposed scaffold will be comprised of peptide amphiphiles (PAs), which are synthetic materials made entirely from common biological components (peptides and fatty acids). PAs of the family described here are well-known to form high aspect ratio nanofibers in aqueous solution, yielding a fibrous gel that resembles the extracellular matrix in nanostructure. PAs will be outfitted with dexamethasone (Dex) bound to the PA via a hydrolysable hydrazone linkage. Dex is well-known to induce osteogenesis of hMSCs in 2-dimensional culture, but an injectable, 3-dimensional, Dex-releasing gel capable of differentiating hMSCs and supporting their proliferation in vivo has never been reported. Once a Dex-releasing PA has been synthesized, Dex release will be measured from the PA gels into buffer in the absence of cells. Zero-order hydrolysis of the hydrazone bond is expected to release Dex in a slow, sustained manner. After release kinetics have been determined, hMSCs will be cultured in three dimensions inside the proposed Dex-releasing gel, which will be constructed with a diluent PA to provide structural support. Characterization of the gel will be accomplished using electron microscopy, small-angle X-ray scattering, rheology, and circular dichroism. A combination of staining, gene expression, and protein expression will be used to quantify the extent of osteogenesis and mineral production. In parallel with the Dex-releasing PA, a PA that displays a peptide sequence mimicking the growth factor bone morphogenic protein 2 (BMP-2) will also be developed. The proposed BMP-2-mimetic PA may function in synergy with the Dex-releasing PA, eventually yielding faster bone production and healing than either component alone. Several in vitro experiments will be performed to compare the two methods of osteogenesis, which function through different cellular pathways. If successful, the Dex-releasing and BMP-2-mimetic PA scaffolds developed and studied here may be used as injectable materials in conjunction with hMSCs for bone development in humans. Such a treatment may drastically improve the quality of life of patients with severely compromised bone regeneration capacities due to bone defects, removal of cancerous bone, or osteoporotic fractures. PUBLIC HEALTH RELEVANCE: Bone defects due to cancer, trauma, or osteoporosis are an increasing problem in the context of an aging population. The proposed research will investigate an injectable material that when mixed with adult mesenchymal stem cells may be capable of promoting bone regeneration when the body's natural regeneration capacity is compromised. The results of this work will inform future studies aimed at improving the quality of life of patients with severe bone defects.

描述（由申请人提供）：能够与成年干细胞相互作用以将其分化为特定末端细胞类型的新材料将在再生医学的新兴领域中起重要作用。提出的工作详细介绍了一种诱导人间充质干细胞（HMSC）分化为三维支架内部成骨细胞谱系的策略，并在骨再生中应用。拟议的支架将由肽两亲物（PA）组成，它们是完全由常见的生物学成分（肽和脂肪酸）制成的合成材料。此处描述的家族的PA是在水溶液中形成高纵横比纳米纤维的众所周知的，产生了类似于纳米结构中细胞外基质的纤维凝胶。 PAS将通过可通过水解的氢化链接连接到PA的地塞米松（Dex）配备。 DEX在二维培养物中诱导HMSC的成骨，但从未报道过能够区分HMSC并支持其在体内增殖的，但从未报告过可诱导HMSC的成骨。一旦合成了dex释放PA，在没有细胞的情况下，将从PA凝胶中测量DEX释放。悬挂式键合的零级水解将以缓慢，持续的方式释放DEX。确定释放动力学后，HMSC将在提出的脱氧凝胶内的三个维度中培养，该凝胶将使用稀释剂PA构建以提供结构支持。凝胶的表征将使用电子显微镜，小角度X射线散射，流变学和圆形二色性。染色，基因表达和蛋白质表达的组合将用于量化成骨和矿物质的生产程度。与脱氧释放的PA并联，还将开发模仿生长因子骨形态蛋白2（BMP-2）的肽序列的PA。提出的BMP-2模拟PA可能与脱氧释放PA的协同作用，最终比单独的任何一个组件产生更快的骨产生和愈合。将进行几种体外实验，以比较两种通过不同细胞途径发挥作用的成骨方法。如果成功，则在此开发和研究的dex释放和BMP-2模拟PA支架可与HMSC一起用作可注射的材料，用于人类的骨骼发育。这种治疗可能会大大改善由于骨缺损，去除癌性骨骼或骨质疏松性骨折而导致骨骼再生能力严重损害的患者的生活质量。 公共卫生相关性：在衰老人群中，由于癌症，创伤或骨质疏松症引起的骨骼缺陷是一个越来越多的问题。拟议的研究将研究一种可注射材料，当与成年间充质干细胞混合时，当人体的自然再生能力受到损害时，可能能够促进骨骼再生。这项工作的结果将为未来的研究提供旨在改善严重骨缺陷患者生活质量的未来研究。