Date of Award

2014

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Systems Engineering

First Advisor

Desai, Salil

Abstract

The interface between a medical device and its surrounding tissue can be critical to biocompatibility, performance and therapeutic effectiveness. Careful choice and application of materials at this interface is therefore a key to the success of any medical device. This research employed a novel direct-write inkjet printing technique for polymeric surface modification of bioresorbable AZ31 Mg alloy towards corrosion control and tunable release of bioactive agents. In the first phase of this research, the direct-write inkjet printing technique was successfully used to fabricate thin films of different blends of poly (ester-urethane) urea embedded with taxol coatings on mechanically polished AZ31 Mg coupons. A corrosion study was performed using the electrochemical impedance spectroscopy (EIS) technique. The polarization resistance values obtained using the equivalent circuit model were analyzed using the ECHEM analyst commercial software developed by Gamry®. The polarization resistances obtained indicated that the corrosion resistance of the polymeric materials increases in this order: uncoated AZ31 < PEUU-SB < PEUU-PC < PEUU-V. In the second phase, thin films of PCL-ACP polymeric coatings were deposited on mechanically polished Ti, AZ31 and AZ31 pre-treated with HF substrates. The effect of ACP concentration and substrate type on cell proliferation was studied. Cyto-compatibility studies showed that osteoblast were biocompatible and displayed active proliferation for PCL-ACP coatings of different substrates. Osteoblast viability studies conducted using Ti coated substrates, showed higher percentage of viable osteoblast comparable to the positive controls (bare Ti and TCPS). These results lay foundation for the use of the direct-write fabrication technique for developing bioresorbable medical implants towards corrosion control and tunable release of bioactive agents.

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