Materials Science and Engineering

Biography

Biography: Xiang Zhang

Abstract

This presentation will introduce new theories and industry practice for design and development of polymer-based ceramic hybrids.  The evolution from pure polymer-based medical devices to polymer-based ceramic hybrids is to meet unmet market needs for better clinical performance over existing systems.  There are many factors that can affect medical implant performance and, historically, most of them have been well studied, such as bioactivities and biocompatibility.  In this presentation, new concept will be mainly addressing issue surround biomechanics, biofracture mechanucs and biofunctionality for design and development of new hybrid biomaterials for implant applications.  It will report the principles on formulations for two type of the new systems.  One family is of biodegradable and bioresorbable hybrids and 2nd is of non-biodegradable hybrids.  It will be followed by design and development of medical devices in view of industry practice with clinical performance considerations of medical devices.  The main topics covered in the presentation include: (a) New concepts and synthetic pathway of polymer-based ceramic hybrids; (b) Nano/Micro mechanics and nano/micro fracture mechanics; (c) Industry practice – two case studies will be used to demonstrate on how to design and develop polymer-based ceramic hybrid biomaterials and relevant processing technology for the applications of medical implants.  Cardiovascular stent, as an example is traditionally made of metal such as Bare Metal Stents (BMS) or with drug coatings, i.e. Drug Eluting Stents (DES).  There are, however, clinical complications associated with these technologies, such as, early stage restenosis, very late thrombosis and risk associated with revision surgery.  In light of these challenges research focus has turned to the development of bioresorbable vascular scaffold (BVS) technologies.

We have developed new bioresorbable polymer-based ceramic stent that has been reinforced resorbable therapeutic cardiovascular stent to address the known limitations of cardiovascular technologies.  We have developed a bioresorbable stent with intrinsic toughness for handling and deployment via balloon angioplasty, radial strength, controlled drug-release technology to suppress restenosis and surface functionalisation to promote endothelialisation to reduce risk of thrombosis. We present the novel synthetic polymer-ceramic composites developed as candidate stent-core materials, both their preparation and the characterisation of their mechanical behaviour, in vitro degradation will be presented.

Acknowledgement

Thanks to Prof. Ruth Cameron of University of Cambridge for assistance for materials characterization and Prof. Wenxin Wang of Vornia Ltd for synthesis some of the polymers used in the research.  Thanks also to Dr Chris Lovell and Dr Mark Cresswell of Lucideon who have done most of the work in this presentation

Recent Publications

1. Science and Principles of Biodegradable and Bioresorbable Medical Polymers - Materials and Properties, 2016 by Elsevier

2. Inorganic Controlled Release Technology, 1st Edition - Materials and Concepts for Advanced Drug Formulation, 2015 pub. by Elsevier

3. Inorganic Biomaterials: Structure, Properties and Applications, 2014 pub. By Smithers Rapra

4. Polymer, 41 (2000) 3797-3807, X C Zhang, M F Butler and R E Cameron, “The Ductile – Brittle Transition of Irradiated Isotactic Polypropylene Studies Using Small Angle X-ray Scattering and Tensile Deformation”

5. Advanced Materials, 12 December 2015, Yongjiu Lei, Ruize Sun, Xiangcheng Zhang, Xinjian Feng, Lei Jiang, “Oxygen-Rich Enzyme Biosensor Based on Superhydrophobic Electrode”

6. Polymer, 41 (2000) 3797-3807, X C Zhang, M F Butler and R E Cameron. “The Ductile – Brittle Transition of Irradiated Isotactic Polypropylene Studies Using Small Angle X-ray Scattering and Tensile Deformation”