MGF纳米微球静电纺丝材料及对hMSC增殖和迁移的影响

力生长因子(MGF,mechano-growth factor)是由Yang等发现并命名,是细胞对力刺激响应的产物,对人骨髓间充质干细胞(hMSC,human mesenchymal stem cells)有重要的调控作用。利用静电纺丝技术(electrospinning)及相分离法制备了基于聚已内酯(PCL,polycaprolactone)的含MGF的葡聚糖纳米微球的纤维支架,间接性地保护了MGF活性,采用扫描电镜和透射电镜对微球和纤维支架进行了基础表征。同时,进一步采用激光共聚焦显微镜和酶标仪分别考察了纳米微球中释放出来的MGF对细胞的作用。研究结果表明含MGF的纳米微球支架能够显著促进hMSC增殖和迁移。此静电纺丝纤维支架能够较好地保护MGF的活性,有望在组织工程领域得到应用。     

Bone tissue engineering therapeutics: controlled drug delivery in three-dimensional scaffolds

This paper provides an extensive overview of published studies on the development and applications of three-dimensional bone tissue engineering (TE) scaffolds with potential capability for the controlled delivery of therapeutic drugs. Typical drugs considered include gentamicin and other antibiotics generally used to combat osteomyelitis, as well as anti-inflammatory drugs and bisphosphonates, but delivery of growth factors is not covered in this review. In each case reviewed, special attention has been given to the technology used for controlling the release of the loaded drugs. The possibility of designing multifunctional three-dimensional bone TE scaffolds for the emerging field of bone TE therapeutics is discussed. A detailed summary of drugs included in three-dimensional scaffolds and the several approaches developed to combine bioceramics with various polymeric biomaterials in composites for drug-delivery systems is included. The main results presented in the literature are discussed and the remaining challenges in the field are summarized with suggestions for future research directions.     

Metallic ions as therapeutic agents in tissue engineering scaffolds: an overview of their biological applications and strategies for new developments

This article provides an overview on the application of metallic ions in the fields of regenerative medicine and tissue engineering, focusing on their therapeutic applications and the need to design strategies for controlling the release of loaded ions from biomaterial scaffolds. A detailed summary of relevant metallic ions with potential use in tissue engineering approaches is presented. Remaining challenges in the field and directions for future research efforts with focus on the key variables needed to be taken into account when considering the controlled release of metallic ions in tissue engineering therapeutics are also highlighted.     

Cell distribution profiles in three-dimensional scaffolds with inverted-colloidal-crystal geometry: modeling and experimental investigations

Limited ingrowth of stromal cells is observed when a three-dimensionally ordered scaffold possessing inverted-colloidal-crystal geometry is used to culture adherent cells. In this work, a computational model explaining, as well as predicting, experimental cell distributions is developed. It incorporates a modified Contois cell-growth model that includes the effects of nutrient saturation, competitive product inhibition, and cell-contact inhibition to describe the scaffold-cell system. Our results agree with the hypothesis that the rapid growth of cells on the surface of the scaffold depletes the nutrient supply to the core, resulting in the preferential growth on the exterior of the scaffold. When the cells are cultured in a scaffold subjected to a uniform velocity field, they penetrate to a greater extent into the scaffold core. Alternative seeding and culture strategies are suggested and evaluated.