Research Focus

For the in vivo approach to tissue or organ replacement, we are interested in developing scaffolds and techniques that will be conducive to the reconstitution or maintenance of normal tissue micro architecture. Disruption of normal tissue microarchitecture can lead to scarring or degeneration resulting in loss of or impaired function. Therefore, we are developing and studying novel biomaterials and processing techniques to produce scaffolds suitable for tissue engineering. In particular we are interested in understanding the effects of scaffold characteristics on cellular and tissue development in order to prevent deleterious processes. We are also pursuing, in collaboration with Prof. Backman's research group, the development of minimally invasive, quantitative and real-time techniques to assess changes in the microarchitecture and function of the scaffolds and bioengineered tissue under study.

For the ex vivo approach to tissue or organ replacement, we are designing, constructing and characterizing novel extracorporeal devices for blood purification that are based on protein and cell engineering. In particular, we are investigating and developing immobilized single-chain antibody fragment technology to confer specificity to the blood purification process of patients with chronic kidney failure.
 

Biomaterials

• Poly(diol citrate) elastomeric and composite scaffolds for tissue engineering
• Nanoshells and contrast agents for multi-label molecular imaging via light scattering spectroscopy

Tissue engineering

Tissue engineering is a relatively new field that integrates material science, polymer chemistry, and cell/molecular biology in order to better understand, repair or regenerate tissues and organ systems. Projects in this area include:

• Vascular tissue engineering: Cardiovascular disease is the number one killer in the U.S.A. and vascular disease is a significant contributor to the number of deaths. We are interested in designing and evaluating biodegradable materials that would be conducive to the formation of small-diameter blood vessels and heart valves. Specifically we are interested in: a) the characterization and use of progenitor cells from blood for tissue generation and b) the effect of the mechanical properties of the biomaterial scaffold on cell signaling and tissue generation. Also, we have a special interest in understanding the scaffold parameters that would modulate and enable functional tissue engineering in vivo.

• Orthopaedic tissue engineering: We are addressing problems associated with knee injuries, specifically injuries to the meniscus and ligament. Therefore, our efforts in this area focus on cartilage and ligament. The meniscus is a cartilaginous structure located in the knee and meniscal as well as ligament tears are a common occurrence during sports activities. A truncated or impaired meniscus or ligament can lead to joint malfunction and to osteoarthritis. Tissue engineering, controlled drug delivery, and gene-expression profiling are some of the tools that can be used to investigate novel ways to promote wound healing within the avascular zone of the meniscus. In the case of chronic degeneration of this tissue, cell/biomaterial interactions are studied with the goal of creating a biohybrid meniscus that could potentially be used for transplantations. Our efforts to engineer a ligament focus on the development of a composite scaffold that would support cyclic loading and cell infiltration in the intra-articular component of the scaffold while promoting bone growth at the fixation points. We are also developing novel biodegradable bone screws to improve the fixation of ligament and tendon grafts

Biotechnology

Recombinant DNA techniques, surface modification, and engineering principles are being used to design and develop devices that can neutralize the activity of macromolecules in the blood that are implicated in pathologic conditions or deleterious side effects. For example, the specific removal of beta-2-microglobulin from blood is part of an effort to control the concentration of proteins implicated in the formation and stabilization of amyloid deposits that are present in patients with end stage renal disease. Projects include:

• Design, synthesis and characterization of single chain-variable region antibody fragments for immunoadsorption
• Novel particle/cell fluidization devices for extracorporeal blood purification (the vortex flow plasmapheretic reactor (VFPR))