Molecular Engineering of Biomimetic Hydrogel-Based Lubricious Films

该奖项的研究目标是检验仿生的“智能”人造润滑剂，并在微观水平上确定界面相互作用对受限聚合物薄膜摩擦学性能的影响。将刺激响应性聚(N-异丙基丙烯酰胺)(PNIPAM)水凝胶薄膜与透明质酸(HA)进行分子工程，模拟天然滑液中的润滑素-HA复合体，构建智能润滑膜。这些胶体润滑剂的界面材料性能可以通过外部刺激(如温度和生物聚合物添加剂)进行主动调整和优化，以模拟滑液的超级润滑性。同时进行的单粒子成像和界面作用力实验将考察聚合物微结构和动力学如何赋予不同薄膜厚度的受限PNIPAM-HA薄膜特定的粘弹性。如果成功，该研究结果将有助于阐明生物润滑机理，促进对关节炎和干眼症状的理解，以及设计具有最佳润滑性能的智能薄膜。在单颗粒水平上破译的受限有色薄膜的微结构-粘弹性关系，将有助于深入了解原子和纳米尺度润滑现象的基本原理。从这一努力中获得的知识可以转化为合理地设计与人工生物溶剂和有色生物医学装置相关的智能仿生聚合物组件或涂层。将通过课堂教学和实验室研究，培训研究生和本科生，以及未被充分代表的少数群体，如工程专业的女学生，学习新的和先进的材料表征技术。该项目还寻求与润滑油和汽车行业以及印第安纳州S当地的整形外科行业建立强大的联盟，以帮助学生、科学家和工程师更好地合作。

The research objective of this award is to examine biomimetic "smart" artificial lubricants and determine the role of interfacial interactions on the tribological properties of confined polymeric thin films at a microscopic level. The intelligent lubricious films will be constructed by molecular engineering of stimuli-responsive poly (N-isopropylacrylamide) (PNIPAM) hydrogel thin films added with hyaluronic acid (HA) to simulate the lubricin-HA complexes in natural synovial fluids. The interfacial materials properties of these colloidal lubricants can be actively tuned and optimized by external stimuli, such as temperature and biopolymer additives, to mimic the super-lubricity of synovial fluids. Concurrent single-particle imaging and interfacial force experiments will be conducted to examine how the polymeric microstructures and dynamics endow specific viscoelasticity of confined PNIPAM-HA thin films of varied film thickness.If successful, the results of this research will elucidate the biolubrication mechanism and advance the understanding of arthritis and dry-eye symptoms as well as the engineering of intelligent thin films with optimal lubrication properties. The microstructure-viscoelasticity relationship of confined lubricious thin films, deciphered at a single-particle level, will give insight to the fundamentals in atomic and nano scale lubrication phenomena. The knowledge gained from this endeavor can be transformed to rationally design intelligent biomimetic polymeric assemblies or coatings relevant to artificial biolubricants and lubricious biomedical devices. Graduate and undergraduate student participants, as well as underrepresented minorities such as female students in engineering majors, will be trained with new and advanced materials characterization techniques through classroom instruction and laboratory research. This project also seeks to establish a strong coalition with lubrication and automotive industries as well as Indiana?s local orthopedic industry to help students, scientists, and engineers work well together.