Electrochemically Guided Collagen Synthesis for Functional Tissue Engineering

用于功能组织工程的电化学引导胶原蛋白合成

• 批准号: 7587640
• 负责人: Ozan Akkus
• 金额: $ 14.57万
• 依托单位: PURDUE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-26 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7587640
• 关键词: Affect; Amendment; Behavior; Binding; Biocompatible Materials; Biological Assay; Biological Factors; Biomechanics; Biomimetics; Blood Vessels; Body Fluids; Bone Marrow; Caliber; Cells; Collagen; Collagen Fibril; Collagen Type I; Condition; Connective Tissue; Cues; Data; Dermatan Sulfate; Development; Dimensions; Fiber; Fibronectins; Fostering; Gel; Genotype; Glutaral; Goals; Hand; In Vitro; Length; Ligaments; Measures; Mechanics; Mesenchymal Stem Cells; Methods; Molecular; Morphology; Nature; Pathway interactions; Pattern; Peptides; Phase; Phenotype; Phosphate Buffer; Play; Process; Property; Public Health; Range; Rattus; Role; Saline; Shapes; Simulate; Site; Skin; Solutions; Stem cells; Tenascin; Tendon structure; Testing; Tissue Engineering; Tissues; Tubular formation; Weight-Bearing state; adult stem cell; analog; base; biomaterial compatibility; bone; clinically significant; concept; crosslink; decorin; density; desire; electric field; genipin; improved; novel; pH gradient; physical property; progenitor; prospective; repaired; research study; scaffold; size; synthetic construct; three dimensional structure

DESCRIPTION (provided by applicant): Collagen plays a central role as a biomaterial and as a scaffold in the regenerative tissue replacement strategies. Existing synthetic analogs of collagen have extremely poor biomechanical properties in comparison to the tissues they are targeted to replace due, in part, to the lack of orientation in hierarchical orders above the level of fibers. The overall goal of the proposed study is to demonstrate the feasibility of a novel biomechanically competent collagenous tissue engineering scaffold fabricated by: 1) an unconventional electrochemical process to attain an unprecedented level of molecular alignment and molecular packing density persistent across multiple levels of structural hierarchies, and, 2) the control of interfibrillar attachment by use of a biomimetic decorin-like linkage molecule. Phase 1 of proposed studies will elucidate the mechanisms by which collagen solutions achieve long-range order under the effect of weak currents applied to directly to the solutions. The effects of pH gradient electric current amplitude and collagen concentration on the hierarchical organization of collagen will be investigated to optimize the synthetic process. The strength of resulting oriented collagen gels will be improved by identifying the appropriate type and concentration of crosslinking amongst genipin and glutaraldehyde. {The D-banding pattern and collagen fibril diameter will be improved by modulating the phosphate buffered saline treatment conditions.} The viscoelastic properties of oriented constructs will be modified by decorin mimics consisting of dermatan sulfate attached to peptide motifs which selectively bind to type I collagen molecules. Mechanical properties of resulting synthetic constructs will be assessed by macroscale mechanical tests and compared to those of rat tendon, a reference natural tissue. {Phase 2 is going to assess the differentiation of bone marrow derived mesenchymal stem cell progenitors on this material towards tenocytic lineage and foster this differentiation pathway by the mechanical cue.} Overall, the proposed study will: a) optimize the fabrication process variables of a novel fabrication method to obtain highly oriented tendon-mimicking constructs, and, b) assess the feasibility of the material as a tissue engineering scaffold by investigating phenotypic and genotypic behavior of bone marrow derived stem-cell progenitors seeded within the three-dimensional structures consisting of multiple collagenous bundles. A biomaterial of this nature may play a key role in creating strategies towards replacement of load bearing connective tissues such as tendons, ligaments, bones and vascular walls provided that the current study proves its feasibility. PUBLIC HEALTH RELEVANCE: The overall goal of the proposed study is to demonstrate the feasibility of a novel collagenous tissue engineering scaffold with mechanical properties converging those of tendon or ligaments. The study will assess the promise of this novel material by investigating whether adult stem cells seeded on this material differentiate to act like tendon cells.

描述（由申请人提供）：胶原蛋白作为生物材料和再生组织替代策略中的支架发挥着核心作用。与它们要替代的组织相比，现有的合成胶原类似物具有极差的生物力学特性，部分原因是在纤维水平之上的分层顺序中缺乏定向。拟议研究的总体目标是证明一种新型的具有生物力学能力的胶原组织工程支架的可行性，该支架通过以下方式制造：1）非常规的电化学过程，以达到前所未有的水平的分子排列和分子堆积密度，在多个层次的结构层次上持续存在， 2) 使用仿生核心蛋白聚糖样连接分子控制原纤维间附着。拟议研究的第一阶段将阐明胶原蛋白溶液在直接施加到溶液的弱电流的作用下实现长程有序的机制。研究pH梯度电流幅值和胶原蛋白浓度对胶原蛋白分级组织的影响，以优化合成工艺。通过确定京尼平和戊二醛之间适当的交联类型和浓度，将提高所得定向胶原凝胶的强度。 {D带模式和胶原纤维直径将通过调节磷酸盐缓冲盐水处理条件来改善。}定向构建体的粘弹性特性将通过核心蛋白聚糖模拟物进行修改，该模拟物由附着在选择性结合 I 型胶原蛋白的肽基序上的硫酸皮肤素组成分子。所得合成结构的机械性能将通过宏观机械测试进行评估，并与大鼠肌腱（一种参考天然组织）的机械性能进行比较。 {第二阶段将评估这种材料上骨髓来源的间充质干细胞祖细胞向腱细胞谱系的分化，并通过机械提示促进这种分化途径。}总体而言，拟议的研究将：a）优化a）的制造工艺变量b) 通过研究骨髓干细胞的表型和基因型行为来评估该材料作为组织工程支架的可行性祖细胞接种在由多个胶原束组成的三维结构内。如果当前的研究证明其可行性，这种性质的生物材料可能在制定替代承重结缔组织（如肌腱、韧带、骨骼和血管壁）的策略方面发挥关键作用。 公共健康相关性：拟议研究的总体目标是证明新型胶原组织工程支架的可行性，其机械性能与肌腱或韧带的机械性能一致。该研究将通过调查种植在这种材料上的成体干细胞是否分化为像肌腱细胞一样的行为来评估这种新型材料的前景。