Alternative tissue engineering scaffolds based on starch: processing methodologies, morphology, degradation and mechanical properties

http://www.sciencedirect.com/science/journal/09284931An ideal tissue engineering scaffold must be designed from a polymer with an adequate degradation rate. The processing technique must allow for the preparation of 3-D scaffolds with controlled porosity and adequate pore sizes, as well as tissue matching mechanical properties and an appropriate biological response. This communication revises recent work that has been developed in our laboratories with the aim of producing 3-D polymeric structures (from starch-based blends) with adequate properties to be used as scaffolds for bone tissue engineering applications. Several processing methodologies were originally developed and optimised. Some of these methodologies were based on conventional melt-based processing routes, such as extrusion using blowing agents (BA) and compression moulding (combined with particulate leaching). Other developed technologies included solvent casting and particle leaching and an innovative in situ polymerization method. By means of using the described methodologies, it is possible to tailor the properties of the different scaffolds, namely their degradation, morphology and mechanical properties, for several applications in tissue engineering. Furthermore, the processing methodologies (including the blowing agents used in the melt-based technologies) described above do not affect the biocompatible behaviour of starch-based polymers. Therefore, scaffolds obtained from these materials by means of using one of the described methodologies may constitute an important alternative to the materials currently used in tissue engineering

Design and processing of starch based scaffolds for hard tissue engineering

The design and processing of appropriate porous 3-D scaffolds is one of the most important steps towards the regeneration of damaged tissues/organs using a tissue engineering approach; since most of the cell types require an adequate support in order to form the intended new tissue. TIlls work reports the development of several processing techniques that have been specifically designed for producing biodegradable scaffolds from a range of starch based polymers. The developed methods include melt based processing technologies (based on injection molding and extrusion using blowing agents), combined techniques based on solvent casting and on compression molding associated to particle leaching, It .has been possible to produce scaffolds that combine an appropriate degradation rate, with controlled porosity and adequate pore sizes, as well as tissue matching mechanical properties. Furthermore, the developed methods have no negative effect on the biocompatible behavior of the starch based polymers

Polymeric materials for impact and energy dissipation

Automotive plastic components are often required to withstand impact loadings and dissipate energy in automotive collisions, protecting occupants and pedestrians. The design of plastic components against impact loading is not a trivial engineering task, but still a challenging activity. The optimisation of the impact behaviour of plastic products requires a global approach involving material properties, processing methods and geometrical design solutions. This communication presents solutions to develop plastic components requiring high impact performance, based on a highly interrelated triad: polymeric material systems with improved impact toughness, processing methods for plastic products with enhanced toughening performance and design solutions for plastic components with superior impact behaviou