The groups of Robert Tilton and Todd Przybycien are conducting detailed studies on the effects of protein PEGylation for the primary purpose of optimizing drug delivery.  For example, PEG conjugation to lysozyme significantly increases the kinetics of desorption from PLGA surfaces. 

Controlled release of therapeutic agents is a critical component of tissue engineering.  Fundamental investigations on the effects of delivery vehicles are important for promoting tissue repair and treating diseased tissue.  In collaboration with faculty in Physics Department and UPMC, the groups of Bob Tilton and Todd Przybycien are developing surfactant-based aerosols to deliver antibiotics in pulmonary infections.

The group of James Schneider has developed a highly effective method for performing size-based electrophoresis of DNA.  In end-labeled free-solution electrophoresis (ELFSE), an electrically neutral “drag-tag” is appended to DNA to add significant hydrodynamic drag. This method is the first example of a noncovalent drag-tag used to separate DNA of 1000 bases based on both size and sequence.

The group of new Assistant Professor Chris Bettinger is developing dynamic polymer interfaces with patterned spatiotemporal control over the surface to study various cellular responses to materials properties such as surface topography.

In a visionary review, Prof. Phil LeDuc and co-authors defined many of the opportunities in using nanobiotechnology to create biologically inspired nanofactories. The goal is to develop molecular machinery that could produce therapeutic compounds in patients in response to specific environmental cues.  The authors outlined six essential components for such nanofactories and identified a broad range of disease conditions for which these could drastically improve the standard of care.

The group of new Assistant Professor Adam Feinberg is developing strategies for preparing defined self-assembled matrices composed of extracellular matrix components.  Independent control of structure and composition in these nanofabrics will provide advanced scaffolds for tissue engineering.

Despite the excitement over the potential advances of nanobiotechnology, significant health concerns have been raised over the safety of these materials.  Kris Dahl, Yu-li Wang, and their collaborators have shown that carbon nanotubes significantly affect intracellular and ex vivo actin polymerization.  In addition, the group of Bob Tilton is investigating the impacts of engineered nanoparticles on microbial viability and biodiversity in the environment, in collaboration with faculty in Civil and Environmental Engineering.

Biomedical Engineering Department’s research in tissue engineering focuses on developing advanced materials for controlling biological processes that are critical in regenerating missing or damaged tissue.  These investigations are based on establishing a fundamental understanding of important biological processes in cell differentiation and signaling.  Craniofacial bone regeneration is a central focus of Jeffrey Hollinger.  The goal is to produce tyrosine-derived polycarbonates and polycaprolactone-fumarate-based therapeutics supplemented with recombinant human bone morphogenetic protein-2 (rhBMP-2) and recombinant human platelet-derived growth factor (rhPDGF) to regenerate traumatically damaged bone in the craniomaxillofacial complex.

Inkjet-based bioprinting technology is being applied by the groups of Lee Weiss and Phil Campbell to create defined spatial patterns of hormones immobilized on delivery matrices, in order to localize stem fates in vitro and in vivo to direct spatial differentiation.  Such constructs have been demonstrated to control cell proliferation, migration, and differentiation in spatial register to these patterns. Current research is focused on guiding the repair of multi-tissue units, such as muscle-tendon-bone.

The group of Newell Washburn has developed matrices that locally control inflammation.   Based on cytokine-neutralizing monoclonal antibodies conjugated to high molecular weight polysaccharides, these materials have been shown to be effective in inhibiting inflammation-induced necrosis that follows partial-thickness burns.

The group of Stefan Zappe has developed a new method for cell encapsulation based on agarose gel templating and capsule wall growth through complex coacervation of oppositely charged polyelectrolyte biopolymers.  Cells are induced to differentiate predominantly into neurons rather than astrocytes without fibroblast growth factor.  This technology may provide vehicles for in vivo neural stem cell delivery that protect cells from initial acute inflammatory responses. 

Integration of biomaterials into devices provides a means for extending the range of function and performance of biosensors and bioMEMS.  Using microfluidic techniques, the group of Phil LeDuc has achieved spatiotemporal control over cellular responses to environmental factors, resulting in a “chemical signal generator” that probes the dynamic responses of live cells to defined stimuli.

The groups of Phil Campbell, Lee Weiss, and Chris Bettinger are collaborating to develop completely biodegradable radio-frequency powered generators and stimulating electrodes for a biodegradable spinal fusion stimulator.  These electrical stimulators, which pass a constant current – in the micro amp range - through tissue, could be applied to aid repair and regeneration of a wide range of tissue types, including musculoskeletal, cardiac, and neural.

To enable genetic screens based on Drosophila embryos, the group of Stefan Zappe has generated MEMS-based microinjector chips for automated embryo injection (e.g. of siRNAs for gene silencing) and for subsequent imaging on a fully automated confocal microscope for automated phenotype recognition.  Single embryos are retrieved from an external reservoir, injected with microinjectors that are embedded at the end of a microfluidic channel, and sent to a second off-chip reservoir for further handling.

The groups of Metin Sitti and Newell Washburn groups are collaborating in the development of biomimetic adhesives.  Fibrillar structures prepared through microfabrication are coated with biomimetic polymers containing the active component found in mussel adhesion proteins.