Abstract

The third-generation biomaterials currently investigated are cell- and gene-activating materials combining both resorbable and bioactive properties. In an effort to develop third-generation biomaterials with controllable physical properties for diverse tissue-engineering applications, we have developed a variety of novel crosslinkable and biodegradable polymers. In this talk, both fundamental and practical challenges in biomaterials and tissue engineering will be addressed and the solutions will be proposed using various polymeric biomaterials for bone and nerve regenerations.
In the first half of this talk, the importance of understanding microscopic chain dimensions, morphologies at different length scales, and macroscopic physical properties in rationally developing novel polymeric biomaterials will be elaborated on a series of multi-block copolymers poly(propylene fumarate-co-caprolactone) (PPF-co-PCL) as well as PPF. PPF-co-PCL can be either chemically crosslinked or photo-crosslinked, making it possible to fabricate 3D scaffolds using various techniques such as stereolithography. The physical properties of the crosslinked form can be modulated efficiently by the copolymer composition. Furthermore, the shape-memory effect has been revealed when the copolymer is semi-crystalline, offering a possibility for developing smart scaffolds.
The second half of this talk will be on the cell-material interactions and biological evaluations of 2D polymer substrates and 3D scaffolds. It is gradually accepted that cells can respond to the substrate stiffness as well as other chemical and topological cues. Without the need of being modified covalently with adhesive proteins, the role of surface stiffness can be reflected in regulating cell responses including attachment and proliferation in both cases of bone marrow stromal cells and SPL201 (Schwann cell precursor line) cells. Two PPF-co-PCL copolymers with distinct PCL compositions were used to fabricate flexible nerve tubes and stiff bone-tissue-engineering scaffolds. Histological analysis of in vivo implantation results showed that the nerve tubes are biocompatible and support axon growth. Rat femoral defect and subcutaneous models were used to evaluate biocompatibility of the scaffolds and bone ingrowth with or without the controlled delivery of recombinant human bone morphogenetic protein-2 (rhBMP-2).

URL:
http://web.utk.edu/~mse/faculty/wang/default.html

Tuesday, January 16, 2007
Seminar at 1:00 p.m.
HED 116
The Scientific Community is Cordially Invited.