Cellular hitchhiking via injectable microparticles

Tissue engineering is a process of developing new tissues in a host. Tissue engineering draws upon revitalizing damaged tissues that otherwise would not heal completely from the body\u27s natural response. To augment the body\u27s natural response to impairment, cells can be transplanted to the afflicted area to boost the healing response. Implementing these cells onto scaffolds and transplanting them into the body improves the healing response dramatically. Tissue regeneration improves when a biodegradable scaffold is used in conjunction with cells to augment the body\u27s healing response. Microparticles provide a surface that can mimic the environment cells perceive in vivo, allowing cells to proliferate and grow on the microparticle surface optimally. When these microparticles are transplanted into the body, the accompanying cells transition into the host tissue as the microparticles degrade. Proteins comprising the extracellular matrix (ECM), like collagen, fibronectin, and laminin, are used to facilitate cell binding to substrates, whether a biomaterial material ex vivo or an enzyme in vivo. Functionalizing the surface of microparticles with ECM proteins improves the adherence of cells which increases the area of tissue regenerated. When cells bind to ECM proteins on a biomaterial, a cascade of signals is initiated which communicates to the cell to spread on the surface of the biomaterial and begin the process of mitosis, leading to proliferation. Cationic polymers have also been shown to improve cell-surface interactions. Functionalizing particles with cationic polymers and extracellular matrix proteins provides a surface optimized for cell attachment and spreading --Abstract, page iv