tailieunhanh - Advances in Biomimetics Part 10

Tham khảo tài liệu 'advances in biomimetics part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Bioinspired Strategies for Hard Tissue Regeneration 307 4. Hard tissue regeneration Bone and dentin are biological composites of organic and inorganic phases have a microstructure that provides an unusual combination of toughness and fracture resistance. Cartilage is composed of specialized cells called chondrocytes that produce a large amount of extracellular matrix composed of Type II collagen proteoglycans and elastin fibers. The rapidly emerging field of tissue engineering holds great promise for the generation of functional bone and cartilage tissues. To this end molecular self-assembly presents a very attractive strategy to construct nanoscale materials for hard tissue engineering. This free energy-driven process spontaneously organizes molecules into ordered structures at multiple-length scales. Molecular Biology techniques can be employed to synthesize protein domains and peptide motifs to create responsive protein for tissue engineering bone dentin and cartilage. A critical requirement for materials designed to interact with cell receptors is the organization of multiple ligands on the surface of a scaffold in order to engage the receptors more effectively. Structures forming a-helices and P-sheets have been used to mediate selfassembly into hydrogels of peptides. In this review we review these processes on a few peptides that possess self-assembling properties and their use in hard tissue engineering. 5. Genetically engineered polypeptides in hard tissue engineering a Self-Assembly of Elastin Elastin is the major extracellular matrix protein which is responsible for the properties of extensibility and elastic recoil of many tissues such as the large arterial blood-vessels lung parenchyma and skin 18 . Elastin is synthesized as a monomer tropoelastin which is subsequently assembled into a stable polymeric structure in the extracellular matrix 19 . This self-assembly property of full-length tropoelastin can also be mimicked by smaller polypeptides. .