Tissue engineering is an emerging field that aims to provide functional tissue replacements for those with tissue loss or organ failure. The strategy combines cells, synthetic polymer scaffolds, and various bioactive factors to mimic the natural conditions that lead to tissue formation. By coupling mathematical modeling with experimental investigations, my research group seeks to design microenvironments that can control cellular responses and subsequent tissue formation. The design and fabrication of these environments may ultimately lead to novel therapeutic strategies within tissue engineering and beyond.

To determine the requirements of the microenvironment, we develop systems that present specific signals, or combinations of signals, and examine mammalian cell responses. The signals are presented in various forms, such as the delivery of genes and growth factors within the scaffold or attachment of molecules to the polymer surface. Of particular interest is the delivery of gene therapy vectors, which encode for proteins that induce tissue formation. Creation of these biomimetic environments utilizes a variety of polymer processing techniques, organic chemistry, and molecular biology. Signals are incorporated into the polymers by covalent modification of polymer or by incorporation during processing. Cellular responses are quantified using a variety of tools, such as microscopy, histology, biochemical testing, and luminescence imaging. Additionally, mathematical models are developed to identify the critical design parameters and make testable predictions regarding drug/gene delivery and cellular responses.

Strategies to enhance tissue formation are developed based on a fundamental understanding of cellular responses to specific signals. Polymer scaffolds may enhance natural tissue regeneration by delivering the appropriate signals or by serving as cell transplantion vehicles. The designer scaffolds are being applied to three models of tissue formation: in vitro maturation of ovarian follicles to preserve female fertility, islet transplantation in diabetes, and nerve regeneration to treat paralysis. This approach of relating tissue development to molecular design of the scaffold may ultimately lead to the formation of engineered tissues that could provide alternatives to whole organ or tissue transplantation.