Stephen P. Massia

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Methods are presented to incorporate polymer-based bioactive matrices into micro-fabricated implantable microelectrode arrays. Using simple techniques, hydrogels infused with bioactive molecules are deposited within wells in the substrate of the device. This method allows local drug delivery without increasing the footprint of the device. In addition, each(More)
The synthetic peptide Gly-Arg-GlyAsp-Tyr (GRGDY), which contains the RGD sequence of several adhesion molecules, was covalently grafted to the surface of otherwise poorly adhesive glass substrates and was used to determine the minimal number of ligand-receptor interactions required for complete spreading of human foreskin fibroblasts. Well-defined adhesion(More)
This research presents immunohistochemical strategies for assessing the interactions at the immediate interface between micro-scale implanted devices and the surrounding brain tissue during inflammatory astrogliotic reactions. This includes preparation, microscopy and analysis techniques for obtaining images of the intimate contact between neural cells and(More)
BACKGROUND Smooth muscle cell (SMC) migration is a vital component in the response of the arterial wall to revascularization injury. Cell surface integrin-extracellular matrix interactions are essential for cell migration. SMCs express both beta1- and beta3-integrins. In this study, we examined the relative functional roles of beta1- and(More)
Nanostructured hydrogels have been developed as synthetic tissues and scaffolds for cell and drug delivery, and as guides for tissue regeneration. A fundamental problem in the development of synthetic hydrogels is that implanted gel structure is difficult to monitor noninvasively. This work demonstrates that the aggregation of magnetic nanoparticles,(More)
In vitro cell adhesion and neurite growth on dextran-coated Benzocyclobutene (BCB) films, covalently grafted with bioactive peptides are investigated. For cell/tissue adhesive surfaces, synthetic peptide GRGDSP was employed. GRADSP was used as an inactive control for nonspecific peptide-induced cell adhesion. For surface coatings with neurite(More)
A new approach for segmenting 3D voxel data sets is presented. It is semi-automatic and consists of two phases. First, the initial seg-mentation is accomplished by voxel labeling using statistical maximum likelihood estimation techniques. The novelty of the present approach is that the type probability distribution function is not required a priori. A(More)
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