利用等离子体技术调控丝素纤维表面性能诱导其仿生矿化的研究

Surface Property Regulation and Biomimetic Mineralization of Silk Fibroin Fibers by Air-plasma Technology

以蚕丝纤维为生物模板的仿生矿化,为骨组织工程和生物材料领域关注热点之一。利用空气等离子体处理改变丝素纤维材料表面理化性能,调控羟基磷灰石纳米棒在材料表面的沉积形貌,制备出仿天然骨组织的丝素纤维/纳米羟基磷灰石(SFF/n HAp)复合材料,并通过傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、扫描电子显微镜(SEM)及透射电子显微镜(TEM)等对SFF/n HAp复合材料的结构、形貌等理化性质进行分析表征。结果显示,虽然未处理丝素纤维及经空气等离子体处理的丝素纤维均能调控羟基磷灰石在其表面沉积,但后者由于表面产生颗粒结构,粗糙度变大,并且引入的含氧官能团使亲疏水性及结晶度发生了变化,导致沉积其上的羟基磷灰石形貌有所差异,尤其是等离子体处理时间对其影响显著:等离子体处理5 min,羟基磷灰石呈现的棒状结构已不再明显;等离子体处理20 min,羟基磷灰石聚集成簇,且其结晶度最高,结晶型与天然骨组织中n HAp的结晶型类似。用经过空气等离子体处理的丝素纤维制备的丝素纤维/羟基磷灰石复合材料有望用于骨组织修复。

Biomimetic mineralization by using silk fiber as template has attracted much attention in bone tissue engineering and biomaterial preparation. In this study, silk fibroin fibers （SFFs） were treated by airplasma to change their surface physical and chemical property. The air-plasma treated-SFFs were used as templates to regulate the morphology of hydroxyapatite deposition on its surface, and the natural bone-like nanocomposite fibers of silk fibroin fiber/nano-hydroxyapatite （SFF/ nHAp） were prepared. Then, Fourier transform infrared spectroscopy （FTIR）, X-ray diffraction （XRD）, scanning electron microscope （SEM） and transmission electron microscope （TEM） were employed to characterize surface morphology, physical and chemical features of the composite material. The results indicate that, although the non-treated SFFs and the air-plasma treated-SFFs could both regulate the deposition of nano-hydroxyapatite on their surfaces, the latter showed much rougher surface due to formation of particle structure on the surface. Moreover, the introduced oxygen-containing groups changed hydrophobicity-hydrophilicity and crystallinity degree of the air-plasma treated-SFFs, resulting in different morphologies of nano-hydroxyapatite deposited on them. Especially, the structures of nano-hydroxyapatite were greatly impacted by the treating time of air plasma. When the SFF was treated by air plasma for 5 minutes, the rod structure of nano-hydroxyapatite was no longer obvious. For 20 minutes, the nano-hydroxyapatite gathered into clusters, and the resultant SFFs had the highest crystallinity degree and possessed crystalline form similar with nHAp in natural bone tissue. The SFF/nHAp composite material prepared by using air-plasma treated-SFFs are potential bone tissue repairing biomaterials.