title：Silicate Based Bioactive Glass and Its Composite with Polymers
Silicate based bioactive glass (SBG) was initially developed for bone repair, which was found to bind to surrounding bone and promote bone regeneration through forming a layer of bone mineral like apatite upon reacting with body fluid. Later, it was also found that SBG can also bind to soft tissues. SBG products have been used in clinics for nearly 30 years. Despite of its great success, SBG has certain disadvantages, mainly lacking of toughness and the burst rising of pH at the beginning of implantation. To overcome the former shortcoming, incorporation of organic/polymeric moieties is a sensible way. For the latter, fine control over the distribution of network modifier ions, e.g. Ca2+ would be a possible approach. The conventional preparation method through high temperature melt-quenching is hard to achieve these goals, however, sol-gel method can produce materials with different structures. Our study showed that by varying types of precursors, the fine structure of glass network can be changed, although the overall elemental compositions are kept the same. We have managed to prepare SBG with similar bioactivity to the clinically used 45S5 at relatively low temperature (200℃ vs 1700℃), which does not cause pH rise when reacting with body fluid. Besides, the low temperature process enables us to prepare composite/hybrid materials in-situ, thus obtain bioactive materials with much improved mechanical properties, i.e. comparable to human cortical or cancellous bones.
Introduction of speaker：
Dong Qiu is currently a professor in polymer physics and chemistry at Institute of Chemistry, Chinese Academy of Sciences. He obtained his PhD in chemistry from the University of Bristol, UK in 2006. After two successive postdoctrate trainings in the University of Bristol and University of Kent, he joined ICCAS as a professor and set up his research group there. His main research interests concentrate on the understanding of structure-property relationship of composite materials. He extensively uses advanced scattering and NMR to explore the multi-length-scale structure of materials in situ, thus guiding the designation of materials with improved performances. He has published ~70 papers in peer-reviewed journals and have applied more than 10 patents. He is currently serving as a Youth Member of the Editorial Board of Chinese Chemical Letters and is an Executive Council Member of the 1st Board of Specialty Committee of Transdermal Drug Delivery of World Federation of Chinese Medicine Societies.