会议时间：2012年5月30日（星期三）下午14：00-16：30
会议地点：曹光彪326会议室
主讲人： Prof. Lucy Di Silvio 和 Dr Jie Huang
报告题目（一）：Engineering Functional Tissues: regeneration of complex and composite tissues
主讲人：Prof. Lucy Di Silvio 英国伦敦国王学院（King’s College London）
英国生物材料学会(UKSB)主席、欧洲生物材料学会(ESB)秘书长
Professor Lucy Di Silvio (LDS)
was specifically appointed to King’s College London in 2003 to establish a cell and tissue engineering group. Her research activity focuses on the development of viable constructs (stem cell technology), translation and application of tissue engineering solutions to important clinical problems related largely to hard tissue regeneration, for craniofacial and orthopaedic applications. She has many national and international research collaborations, and has strong links with student exchange programmes internationally (Europe, Asia).
She has over 22 years experience in the field of biomaterials/tissue engineering and has published over 100 papers in peer-reviewed journals in this field, numerous book chapters and is Editor of “Cell materials Interactions”. LDS was recently appointed as ‘Theme Lead’ for Translational Research (Dental Institute, KCL), and in this role, is responsible for developing research strategies to facilitate integration with clinical scientists in order to assist in the translation of technologies developed by basic scientists to the patient.
Abstract：
With the global ageing population, the demand to replace, repair and regenerate tissues is increasing. Included in this, are a large number of musculoskeletal disorders causing damage to cartilage and bone. Often these are accompanied by significant pain, restricted mobility and high socioeconomic costs. Current approaches to repair cartilage or bone give unpredictable results, and are usually aimed at treating the medical conditions, rather than curing them. Research in functional tissue engineering is developing new approaches for the treatment of degenerative diseases and congenital defects; this critical research has the potential to impact and improve the quality of life of many patients.
The majority of studies aimed at engineering tissues are based on a specific cell response and tissue type, however, without appropriate scaffolds (with a suitable architecture, physico-chemical properties and biologically responsiveness), isolated cells have limited capacity to form fully functionalized tissue. In the past, the focus has been on repairing the damaged tissue individually, without considering the interface structure between cartilage and bone. The use of stem cells is one of the most promising areas of research for the treatment of disease and tissue regeneration. Stem cells have the capacity to differentiate into multiple lineages including bone and cartilage, and are able to do this by responding to biological (growth factors, cytokines) and mechanical cues.
Success of cell-based therapies is highly dependent on the ability of the transplanted cells to be delivered and retained at the site where they are required. Such an integrated system requires an understanding of the basic biology of tissue regeneration in its broadest sense and the development of effective strategies and tools to initiate and control the regenerative process, and in addition, the effect of mechanical and biological cues on cell proliferation and subsequent tissue formation.
Tissue engineering still faces many challenges, including the isolation and expansion of appropriate cell types, the arrangement of assorted cells into correct spatial organization and the creation of the optimal microenvironments for growth and differentiation.The structural features of tissue engineered scaffolds play a pivotal role in supporting the cells to accommodate and guide their growth into a specific tissue; therefore, designing scaffolds that are favourable to cellular growth is of great importance.
This presentation will address the role of scaffolds and cells in engineering functional tissues.
报告题目（二）：Surface modification of medical implants: Coating and patterning
主讲人：Dr Jie Huang 英国伦敦大学学院（University College London）
Dr Jie Huang (JH) BSc, PhD, engaged upon the research of biomaterials for her PhD study at IRC in Biomedical Materials, Queen Mary, University of London, and has taken a great interest in the nanotechnology since joining the Cambridge Centre for Medical Materials, Department of Materials Science and Metallurgy, University of Cambridge in 2001. She established the Biomedical Materials Laboratory at University College London in 2006. JH’s research interests cover the development, characterisation and biological evaluation of bioactive glass, novel substituted hydroxyapatite, biocomposites and nanocomposites for tissue engineering scaffolds and medical applications. Currently there are 10 PhD and 5 MSc students under her supervision. She has published over 60 journal papers, patents and book chapters.
JH is a member of the European Society of Biomaterials and sits on the Editorial Board of Advances in Applied Ceramics: Structural, Functional and Bioceramics. She also sits on the committee of the Biomedical Applications Division, at the Institute of Materials, Minerals and Mining （IOM3）.
Abstract
Hydroxyapatite (HA) coated metallic prostheses, which combine the osteoconductivity of HA and high strength of metal alloys, have been increasingly the choice of joint replacement prostheses by surgeons as the general population lives longer. Surface modification of metallic implant surfaces is one of the key focal points to implantation technology.
Although silicon has only been found in trace quantities in bone mineral, it has been shown that it has a crucial role in bone mineralisation, and is essential in skeletal development. By substituting low levels of silicon in the form of silicate for phosphate into HA structure, Silicon substituted HA (SiHA), has demonstrated enhanced bioactivity and biocompatibility.
In addition to material chemistry, surface topography has been found to positively impact cellular response and is able to enhance the life time of the implant. Recently, an electrically driven jet-based deposition technique has been developed. The process offers the attractive advantages of compatibility with micro-fabrication technology and versatility in pattern specification for advanced implant designs. This technology incorporates nanosized calcium phosphate to mimic the size and chemical composition of bone mineral in a micrometer dimension pattern configuration to guide cellular responses. In vitro cellular studies showed that both pillar and track nanoSiHA patterns were able to encourage the attachment and growth of osteoblast cells, the track patterns provided the favourite surface for the initial cell attachment while a fast cell proliferation rate was found on the pillar pattern, which indicating that the cellular responses can be effectively controlled and guided. This is a significant step forward in the new generational implant for engineering bone repair and replacement.
The presence of resistant infecting organisms is an increasing concern. Antimicrobial nanoparticles have merged as robust alternative antibiotics due to their long lasting biocide with high thermal stability and low toxicity to human cells. Zinc oxide (ZnO) was found to be highly effective against both Gram- positive and negative bacterial associated with orthopaedic infection, such a Staphylococcus aureus. Furthermore, nano-titanium substituted HA (TiHA) was able not only to support the growth of osteoblast cells, but also inhibit the growth of 7 strains of bacteria, including the Methicillin Resistant Staphylococcus Aureus (MRSA) ‘superbug’.
