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Alginate hydrogels are used extensively in cell encapsulation, cell transplantation, and tissue engineering applications. Alginates possess many favorable properties required in biomaterials, but are unable to specifically interact with mammalian cells. We have therefore covalently modified alginate polysaccharides with RGD-containing cell adhesion ligands(More)
Stem cell fate is influenced by a number of factors and interactions that require robust control for safe and effective regeneration of functional tissue. Coordinated interactions with soluble factors, other cells, and extracellular matrices define a local biochemical and mechanical niche with complex and dynamic regulation that stem cells sense.(More)
Matrix metalloproteinases (MMPs) are zinc-endopeptidases with multifactorial actions in central nervous system (CNS) physiology and pathology. Accumulating data suggest that MMPs have a deleterious role in stroke. By degrading neurovascular matrix, MMPs promote injury of the blood-brain barrier, edema and hemorrhage. By disrupting cell-matrix signaling and(More)
Studies were carried out to analyze how different extracellular matrix (ECM) molecules regulate hepatocyte growth and differentiation. Freshly isolated rat hepatocytes were cultured on non-adhesive plastic dishes that were pre-coated with defined densities of either laminin, fibronectin, type I collagen, or type IV collagen. Sparse cell plating densities(More)
Non-viral gene vectors are commonly used for gene therapy owing to safety concerns with viral vectors. However, non-viral vectors are plagued by low levels of gene transfection and cellular expression. Current efforts to improve the efficiency of non-viral gene delivery are focused on manipulations of the delivery vector, whereas the influence of the(More)
Immunotherapy is a promising approach for treating cancer. However, there are limitations inherent to current approaches which may be addressed by integrating them with biomaterial-based strategies. Material platforms have been fabricated to interact with immune cells through spatially controlled and temporally controlled delivery of immune modulators and(More)
Polymer scaffolds have many different functions in the field of tissue engineering. They are applied as space filling agents, as delivery vehicles for bioactive molecules, and as three-dimensional structures that organize cells and present stimuli to direct the formation of a desired tissue. Much of the success of scaffolds in these roles hinges on finding(More)
The development of tissues and organs is typically driven by the action of a number of growth factors. However, efforts to regenerate tissues (e.g., bone, blood vessels) typically rely on the delivery of single factors, and this may partially explain the limited clinical utility of many current approaches. One constraint on delivering appropriate(More)
Vascular endothelial growth factor (VEGF) has been shown to be a potent mediator of angiogenesis that functions as a survival factor for endothelial cells by up-regulating Bcl-2 expression. We have recently reported that human dermal microvascular endothelial cells (HDMECs) seeded in biodegradable sponges and implanted into severe combined immunodeficient(More)
We have proposed engineering tissues by the incorporation and sustained release of plasmids encoding tissue-inductive proteins from polymer matrices. Matrices of poly(lactide-co-glycolide) (PLG) were loaded with plasmid, which was subsequently released over a period ranging from days to a month in vitro. Sustained delivery of plasmid DNA from matrices led(More)