Novel Nanofiber Materials For Tissue Scaffold

There are strict requirements on the properies of the material itself as a tissue repair materials. In this paper, the PLA micro/nano-fiber membrane was prepared by electrospinning as tissue repair scaffold. In order to improve the biocompatibility of the membrane, the bioactive materials hydroxyapatite (HAP) and collagen-Ⅰ(Col-Ⅰ) were doping in the PLA solution respectively and together, obtaining PLA / HAP, PLA / Col, PLA / Col / HAP composite nanofibers membrane which prepared by electrospun. And the properties such as composition, morphology, invasive, and mechanical properties of the four membrane were invested systematically. Cell culture experiments were aslo did on the four membranes. The result showed that, HAP, Col successfully doped into the fiber, and the four membranes were good morphology, the average diameter of fibers were all less than 1μm. Tensile test results indicated that the addition of HAP increased the tensile strength of fiber membrane, Although the addition of Col-Ⅰlead to reduce the mechanical properties, it improve the hydrophilic effectively. Cell culture staining results also showed that the cells growth more dense and uniform in the two membrane containing Col-Ⅰ.The PLA electrospun membrane was with a poor mechanical properties. in order to improve the mechanical strength, the post treatment of hot-press were taken on the membranes under different temperature of 60℃,85℃,100℃at pressure of 500kPa. The results show that the hot-pressing to improve the crystallinity of the fiber membrane, increasing fiber cross-linking point, tensile strength of electrospun membrane increased significantly, which is the best heat treatment temperature of 60℃, when the tensile strength of fiber membrane from 5.38MPa increases to 24.45MPa. Temperaturehigher than 85℃lead to a reduce of elongation at break.The morphology and structure of electrospun fiber have important effect on the function of the membrane. Biodegradable materals with novel structures like spiral structure PLA/PCL composite fiber, necklack structure PLA/PEG composite fiber were prepared by a new electrospinng method use positive and negative two-spinnerets. This particular structure is expected to expand the electrospinning nanofiber material applications in tissue repair.