題 目📄：3D Micro- and Nano-hemispherical Surface Imprints Modulate
報告人：楊偉國教授 香港大學
時 間：2019年11月22日（星期五）15:00
地 點🏄🏿♂️：四號沐鸣樓3083室
主持人：何創龍 教授
歡迎各位老師和同學參加！
報告人簡介👫：
楊偉國，任香港大學醫沐鸣矯形及創傷外科副教授（終身聘任），香港大學深圳醫院深圳骨科創傷修復新技術重點實驗室副主任👨🔧，香港大學立之沐鸣副院長🔪🚣🏿♂️。1998年本科畢業於香港城市大學，主修材料科學🐍。隨後進入香港大學醫沐鸣攻讀骨科碩士及博士學位。畢業後，在矯形及創傷外科學系從事有關矯正脊柱畸形病症的研究工作。楊教授在香港大學醫沐鸣和香港大學深圳醫院均有實驗室研究基地，團隊成員來自材料、醫學、生物學和化學等專業，研究領域包括脊柱畸形及骨創傷🧎🏻♀️➡️🍦、生物醫用材料🧘🏽♂️、鎂合金骨科臨床應用🚵🏿♂️、骨科內植入器械開發等💪🏼。發表了230多篇SCI論文🥊，引用次數超過7500次👦🏽，H-index為49🧯。在Clarivate Analytics的ESI排行榜上🤹🏼♂️，楊教授從2014開始連續6年入選生物材料領域Top1％科學家，共獲得6800多萬港幣經費資助👫。此外, 他還獲取30多項美國或其他國家發明專利，並獲得香港科學會青年科學家獎、香港工程師學會青年工程師優異獎、第十三屆COA學術大會的骨科基礎青年研究二等獎和2019年度香港大學醫沐鸣最佳論文獎等獎項。楊教授還創立了OrthoSmart有限公司，兼任公司首席執行官🪺，致力於骨修復材料的臨床轉化。
報告內容簡介：
Osseointegration and inflammatory response at the bone-implant interface is of paramount importance for the success of orthopaedic implantations and their durability in long-term. Among a number of studies focused on modifying biomaterial physical and chemical properties, the design of surface topography still plays a significant role due to the ease of fabrication and clinical translation. Herein, a series of TiO2 hemisphere patterns ranging from nanoscale to microscale were prepared providing a platform on a 3D structure to study the cellular responses of mouse embryo osteoblast precursor cells (MC3T3-E1) and RAW264.7 macrophages in the absence of other surface features and additional osteogenic supplements in culture medium. This study aims to investigate the underlying correlations between surface topography and cellular behaviors of bone cells. Four groups of TiO2 hemispheres labeled as NWs-90, NWs-500, MWs-1, and MWs-5 with different diameters (i.e. 90 nm, 500 nm, 1 μm, and 5 μm) were prepared for further experiments. The surface properties including topography and materials structure were characterized by SEM, AFM and XRD, while the osteogenic differentiation capability and inflammatory responses of these patterns was validated by mouse pre-osteoblasts and RAW264.7 macrophages, respectively. The results revealed that the cell on flat Ti surface exhibited typical spindle like shapes with smooth boundaries, while the cells on various TiO2 hemisphere patterns presented with various morphologies. The NWs-90 surface was able to upregulate the ALP activity and mineralization, while the Runx2 and OCN genes were up-regulated by NWs-500 surface. Interestingly, NWs-90 sample convinced macrophages towards to M2 polarization with the highest expression level of anti-inflammatory markers (IL-4 and IL-10) and the lowest level of pro-inflammatory markers (TNF-α and IL-1β) among other samples. We believe that different intervals between TiO2 hemisphere patterns generated various mechanical resistances to cells and their filament structures were under stretching. Hence, this stress led to cytoskeleton rearrangement and then modulated cell morphologies, signal transduction indirectly and gene expression directly.
