Vassilios I. Sikavitsas

Research Interests

Our research interests include the use of molecular and cell biology approaches together with engineering principles in developing cellular and tissue engineering strategies for organ regeneration and assessment of human health risk. Our research objectives can be categorized into three major areas:

1. Bone tissue engineering
2. Cell and tissue based biosensors
3. Cancer cell metastasis

Bone Tissue Engineering: During the last decade a number of bone tissue-engineering strategies have been proposed that promise to overcome the limitations of the current therapies. These strategies often require the use of degradable porous scaffolds that can promote the migration of cells from the surrounding tissue or the growth of bone forming cells seeded within the porous network of the scaffold. Most of these bone tissue-engineering approaches envision seeding scaffolds with multipotent adult stem cells that have the potential to enhance new bone formation and can be obtained from the patient's bone marrow. Techniques have been developed that allow osteoprogenitor cells from the bone marrow to be selected and expanded in culture allowing the generation of a large transplantable cell population from a small biopsy. Scaffolds can be seeded with these cells and transplanted to the defect site or cultured in vitro for an additional period prior to transplantation. During this period the cells will proliferate and also deposit bioactive extracellular matrix and growth factors that add osteoinductive potential to the scaffold. The emphasis of our studies is to develop novel strategies for the creation of three-dimensional biodegradable cell/scaffold constructs that are rich in growth factors and extracellular matrix for bone regeneration and repair.

Cell and Tissue Based Biosensors: Biosensors are devices that incorporate biological and physicochemical elements and produce a signal that is related to the presence of an analyte. The analyte is a biomolecule that affects human health. Traditional biosensors identify analytes that are well characterized but fail to identify the presence of unknown agents that can be potentially harmful. Cellular assemblies that mimic tissues can become inherent components of biosensors that will allow prompt and accurate assessment of the environmental and the human health risk posed by a wide variety of agents. Significant efforts in our research group are directed towards the development of three dimensional cell/scaffold constructs that can respond in the presence of harmful agents.

Cancer Cell Metastasis: Cancer cell metastasis is a complex process involving the transport of tumor cells and multiple sequential interactions between tumor cells and the host tissue microenvironment. The identification of these processes can create methodologies that can interrupt the metastatic process. Most of the metastatic tumors in bone cause bone osteolysis but prostate tumor metastasis leads to the formation of bone deposits around the tumor cells. Most of the patients with prostate cancer eventually develop bone cancer. We are investigating the mechanisms leading to cancer cell metastasis in bone in order to provide more effective treatments for the prevention of bone cancer metastasis.

Research Web Sites

Bioengineering Center - Home Page

Selected Publications

"Fluid flow increases mineralized matrix deposition in three-dimensional perfusion culture of marrow stromal osteoblasts in a dose-dependent manner" (with G.N. Bancroft, J. van den Dolder, T.L. Sheffield, J.A. Jansen, C.G. Ambrose, and A.G. Mikos), P.N.A.S.,in press (2002).

"Design of a flow perfusion bioreactor system for bone tissue engineering applications" (with G.N. Bancroft, and A.G. Mikos), Tissue Engineering, in press (2002).

"Formation of three-dimensional cell/polymer constructs for bone tissue engineering in a spinner flask and a rotating wall vessel bioreactor", (with G.N. Bancroft and A.G. Mikos), Journal of Biomedical Materials Research, 62, 136-148 (2002).

"Transport and kinetic processes underlying biomolecular interactions in the BIACORE optical biosensor", (with J.M. Nitsche and T.J. Mountziaris), Biotechnology Progress, 18, 885-897 (2002).

"Flow perfusion culture of marrow stromal osteoblasts in titanium fiber mesh", (with J. van den Dolder, G.N. Bancroft, P.H.M. Spauwen, J.A. Jansen, and A.G. Mikos), Journal of Biomedical Materials Research, in press (2002).

"Biomaterials and bone mechanotransduction", (with J. Temenoff and A.G. Mikos), Biomaterials, 22, 2581-2593 (2001).