Localized release of platelet-derived growth factor (PDGF) in the development of a collagen based tissue repair and regeneration model




Tsao, Christopher

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The need for tissue engineering and regenerative medicine solutions for tissue defects resulting from trauma and disease presents a challenging obstacle. The current gold standard involves tissue/organ transplantation (autografts, allografts, etc.). Treating patients with tissue grafts has proven to have successful outcomes in terms of stability; however restoring native function remains a challenge. Controlled delivery of growth factors can stimulate proliferative and remodeling phases towards the promotion of the native "wound healing cascade." Platelet-derived growth factor (PDGF) has been shown to play an integral role in effecting the chemotactic, mitogenic, morphogenic and metabolic activities of tissue cells and stem cells. The objective of this study is to synthesize and optimize the delivery of nano-encapsulated platelet-derived growth factor from electrochemically aligned type I collagen. By controlling the nanoparticle fabrication and delivery environment, it can allow for optimal loading efficiency, dosage and release kinetics of PDGF, which has the potential to closely mimic physiological activity during wound healing. This was achieved by nano-encapsulating PDGF into a biodegradable polymer (PLGA-m-PEG) via a water-oil-water emulsion. These nanoparticles were then combined with collagen and electrochemically aligned to form collagen-nanoparticle fibers with a PDGF loading efficiency of 23.87 %. In vitro release kinetic results show that this model has a burst delivery of PDGF within the first three days of incubation followed by a sustained release. Thus, the collagen-nanoparticle approach in this study has great potential in delivering growth factors to aid in the regeneration of tissue that is both structurally and functionally sound.


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Collagen, Growth Factor, PDGF, Tissue Engineering



Biomedical Engineering