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Titel: "Polymer blends and composites for biodegradable coronary stents and tissue scaffolds"

 

Lecturer: Professor Debes Bhattacharyya is a Distinguished Professor (holds a Personal Chair) in the Department of Mechanical Engineering and has been the founding Director of the Centre for Advanced Composite Materials (CACM) at the University of Auckland, since 2004. He also holds an Adjunct Professor position at Washington State University, Pullman, USA.  Professor Bhattacharyya was the Head of Mechanical Engineering Department from 1999 to early 2005.

His current research interest primarily includes the mechanics and manufacturing of composite materials. He has held visiting professorships/fellowships at various universities in Australia, Canada, Germany, Hong Kong and the US, and has been awarded a number of international fellowships and honours. He has delivered more than 50 keynote/plenary/invited lectures at different conferences and technical gatherings around the world and has served on the Editorial Advisory Boards of eight international journals and is the Associate Editor of J. of Nano and Smart Materials. Prof. Bhattacharyya has about 450 scientific/technical publications including several edited/authored books and a number of book chapters. He has successfully implemented several international patents. He is a Fellow of the Royal Society of NZ and a Distinguished Fellow of the Institution of Professional Engineers NZ. For his international academic achievements he has recently been awarded an honorary ‘Doctor of Engineering’ (honoris causa) by the University of Southern Queensland, Australia. In 2012, he was also awarded by IPENZ the Supreme Technical Award (John Cranko Award) for his professional and academic contributions in Mechanical & Manufacturing Engineering. 

Abstract:

In several branches of the medical field, from cardiology to orthopaedics to tissue engineering, there has been an increasing trend in the use of biodegradable materials in place of traditional, biostable materials, such as metals, ceramics and synthetic polymers. Biodegradable polymers and their composites are prominent in these areas and are of great interest for research because there is much room for improvement. This paper will focus on the application of polymer blends and composites in bioabsorbable stents and tissue scaffolds.

PLLA is very prominent in the field of bioabsorbable stents but it suffers from brittleness which must be mitigated. One method of doing this is to blend PLLA with rubbery polymers to create ductile blends which strike a balance between ductility, strength, modulus and degradation characteristics. This paper discusses the development of such blends and their mechanical characteristics, from Young´s modulus to creep, which occur during degradation.

PLLA is also a common material under investigation for tissue scaffolds. A large proportion of work in this area focuses on electrospinning to create tissue scaffolds but this requires the use of organic solvents. A process for producing scaffolds without the use of organic solvents has been developed at he Centre for Advanced Composite Materials, The University of Auckland. The process involves drawing of an extruded polymer composite filament to fibrilise the dispersed phase. After producing a network of micro-/nano-fibrils through a common manufacturing technique, the matrix is removed via dissolution in water, leaving a 3-D fibrillar, nanoporous network. This network can be used as a tissue scaffold with the advantage over electrospun networks of having no residual organic solvent content. This paper describes the process of scaffold manufacturing with some results of in-vitro cell culture.

 

 

Date: Tuesday, 9th September 2014, 2 - 4 p.m.

Location: Meeting room PCCL, Roseggerstrasse 12, 8700 Leoben