Fabrication of Novel Biomimetic Polymers Using Combinatorial Peptide Screening

描述(申请人提供)：这些研究的目标是开发和表征用于生物医学应用的独特的合成聚合物-生物分子复合材料。作为初步研究的一部分，组合肽噬菌体展示文库和生物扫描技术已被用于选择独特的多肽序列(T59)，该序列可与氯掺杂聚吡咯(PPyrole)特异性地紧密结合，聚吡咯是一种导电聚合物，已显示出在生物医学应用中的前景，如神经再生。 在拟议的研究中，将研究T59肽与PPyCl(体外和体内)相互作用的亲和力和稳定性，以及这种相互作用的性质。这些信息将有助于理解表面相互作用和生物材料修饰策略，并对于有效地将这些序列应用于体外(例如，生物传感器)或体内(例如，组织工程)应用至关重要。还将用大的生物分子(如NGF)对PPyCl进行官能化，以说明这种方法的多功能性和实用性。这些目标将通过下列具体目标实现：(1)研究T59修饰的PPyCl在体内的反应；(2)使用荧光胺蛋白质分析、原子力显微镜和等温滴定热法定量分析T59与PPyCl的结合；(3)结合多肽变体(使用结合能量学的建模和模拟设计)使用化学和聚合物类似物来研究T59与PPyCl之间的相互作用机制；以及(4)研究通过T59多肽将大的生物分子(即神经生长因子或神经生长因子)附着到PPyCl上的能力。 总体而言，这些研究将探索用于组织工程应用的另一种改性合成聚合物的方法。通过选择和鉴定与合成聚合物高亲和力相互作用的独特的肽序列，人们可以很容易地使用这些肽来修饰聚合物表面(即，可以在一端合成具有聚合物结合序列的肽，而在另一端合成与细胞、药物、生长因子等结合的序列)。这种表面改性策略可以作为一种通用的方法，利用现有的聚合物(包括那些已经获得FDA批准的聚合物和/或那些没有用于偶联反应的官能化基团的聚合物，如PPyCl)来开发生物活性材料，而不会改变材料的整体性质。

DESCRIPTION (provided by applicant): The goal of these studies is to develop and characterize unique synthetic polymer-biological molecule composites for biomedical applications. As part of preliminary studies, combinatorial peptide phage display libraries and biopanning techniques have been used to select a unique peptide sequence ("T59") that specifically and tightly binds directly to chlorine-doped polypyrrole (PPyCl), an electrically conductive polymer that has shown promise in biomedical applications, such as nerve regeneration. In the proposed studies, the binding affinity and stability of the T59 peptide interaction with PPyCl (both in vitro and in vivo) and the nature of this interaction will be investigated. This information will contribute to the understanding of surface interactions and biomaterials modification strategies, and is critical for effectively applying these sequences for either in vitro (e.g., biosensor) or in vivo (e.g., tissue engineering) applications. PPyCl will also be functionalized with large biomolecules (e.g., NGF) to illustrate the versatility and utility of this approach. These goals will be accomplished in the following Specific Aims: (1) Study the in vivo response to PPyCl modified with T59; (2) quantitatively analyze, using fluorescamine protein assays, atomic force microscopy, and isothermal titration calorimetry, the binding of T59 to PPyCl; (3) use chemical and polymer analogs in conjunction with peptide variants (designed using modeling and simulations of binding energetics) to study the mechanism of interaction between T59 and PPyCl; and (4) study the ability to attach large biomolecules (i.e., nerve growth factor or NGF) to PPyCl via the T59 peptide. Overall, these studies will explore an alternate approach for modifying synthetic polymers for tissue engineering applications. By selecting and identifying unique peptide sequences that interact with high affinity to synthetic polymers, one can easily modify the polymer surfaces using those peptides (i.e., peptides can be synthesized with the polymer binding sequence on one end, and a sequence that binds to cells, drugs, growth factors, etc. on the other end). This strategy for surface modification could serve as a versatile method to develop bioactive materials using existing polymers (including those that are already FDA approved and/or those polymers that lack functional chemical groups for coupling reactions, like PPyCl), without changing the bulk properties of the materials.