组织工程骨-血管化策略.ppt

谢谢关注 WPS Office Make Presentation much more fun @WPS官方微博 @kingsoftwps Strategies to Increment Vascularization This is explained by the fact that when implanted, scaffolds with smaller pores tend to be hypoxic, favoring chondrogenesis, whereas in constructs with larger pores the higher oxygen tension promotes the differentiation of MSCs into osteoblast lineage, favoring osteogenesis. Strategies to Increment Vascularization Hierarchical Structures The design and architecture of the scaffold are two other features critical for the formation of a vascular network. One example of an innovative architecture is the nano/ micro fiber-combined scaffold (Figure 2a).[98] This scaffold made from a blend of starch with polycaprolactone (SPCL)[13,94,99–101] combines in the same structure microand nanofibers. Microfibers obtained by fiber bonding were combined with nanofibers producedbyelectrospinning in a single structure. In this way the scaffold material is capable of simultaneously providing the mechanical support for bone repair and mimicking the physical structure of the extracellular matrix (ECM). Strategies to Increment Vascularization As will be described later in greater detail, strategies that include seeding ECs on biomaterials and promoting their adhesion, migration, and functionality might be a solution for the formation of vascularized bone. Therefore, the nanonetwork that resembles the ECM physical structure on SPCL nano/micro fiber-combined scaffolds was designed with the aim to promote EC migration, and to establish a vascular network. Under pro-angiogenic conditions in vitro, this nanonetwork provided the structural and organizational stability for the migration and organization of ECs into capillary-like structures.[102] Strategies to Increment Vascularization Alternatively, Yang et al.[105] used extrusion free forming, a rapid prototyping technique to fabricate ceramic scaffolds with three distinct structure levels: submicrometer pores, aimed to enhance cell/