Ram I. Sharma

Learn More
We investigated substrate dependent paracrine signaling between subpopulations of bone marrow stromal cells (BMSCs) that may affect the formation, or perhaps malformation, of the regenerating tendon to bone enthesis. Polyacrylamide substrates approximating the elastic modulus of tendon granulation tissue and the osteoid of healing bone (10-90 kPa) were(More)
Substrates with mechanical property gradients and various extracellular matrix ligand loadings were evaluated for their ability to direct bone marrow stromal cell differentiation along osteogenic and tenogenic lineages. After verifying reproducible mechanical compliance characteristics of commercial hydrogel gradient substrates, substrates were(More)
Various micro-devices have been used to assess single cell mechanical properties. Here, we designed and implemented a novel, mechanically actuated, two dimensional cell culture system that enables a measure of cell stiffness based on quantitative functional imaging of cell-substrate interaction. Based on parametric finite element design analysis, we(More)
Cell-adhesive ligands organized on nanoscale synthetic biomaterials can potentially recapitulate the nanoscale organization of extracellular matrix and the consequent effects of cell dynamics. In this study, 100 nm albumin nanocarriers (ANC) were fabricated to serve as nanoscale organizational units for a well-defined ligand, the recombinant fragment from(More)
The regulation of cell motility on ligand-adsorbed poly(ethylene glycol) (PEG)-based polymeric biomaterials is governed by variables that are not well characterized. In this report, we examined keratinocyte migratory responsiveness to PEG-variant tyrosine-derived polycarbonates adsorbed with equivalent levels of the cell adhesion ligand, fibronectin. The(More)
The extracellular matrix is a structural support network made up of diverse proteins, sugars and other components. It influences a wide number of cellular processes including migration, wound healing and differentiation, all of which is of particular interest to researchers in the field of tissue engineering. Understanding the composition and structure of(More)
Tissue engineering aims to regenerate new biological tissue for replacing diseased or injured tissues. We propose a new approach to accelerate the deposition of cell-secreted matrix proteins into extracellular matrix fibrils. We examined whether dynamic substrates with nanoscale ligand features allowing for alpha5beta1 integrin recruiting, cellular tension(More)
We propose a novel, single step method for the production of polyacrylamide hydrogels with a gradient in mechanical properties. In contrast to already existing techniques such as UV photo-polymerization with photomasks (limited penetration depth) or microfluidic gradient mixers (complex microfluidic chip), this technique is not suffering such limitations.(More)
Traditional tissue regeneration approaches to activate cell behaviors on biomaterials rely on the use of extracellular-matrix-based or soluble growth-factor cues. In this article, a novel approach is highlighted to dynamically steer cellular phenomena such as cell motility based on nanoscale substratum features of biological ligands. Albumin-derived(More)
Although molecular and physical mechanisms of fibroblast matrix assembly have been widely investigated, the role of adhesive ligand presentation on matrix assembly has only been recently probed (Pereira et al. Tissue Eng., 2007). In the present study, various-sized albumin-derived nanocarriers (ANCs) were fabricated as nanoscale organization units for(More)
  • 1