Pooja Basnett, UoA 3, LS
The University of Westminster provides every opportunity to those who have the determination to succeed. I was awarded with the prestigious Cavendish Scholarship in 2009 to pursue my research after the completion of my Master’s degree. Now that I am approaching the end of my PhD journey, there is a real sense of pride in being a part of such a great institution. During my PhD studies, I have gained valuable skills, expertise and confidence to become an independent researcher. I have also had the opportunity to present my work at various international conferences which has led to important collaborations. My relationship with my supervisor has been the highlight of my PhD studies. Her guidance and support has helped me to have a great research experience. Upon completion, I will not only take away the degree and the skills but also lifelong friendships.
Polyhydroxyalkanoates (PHAs) are biodegradable and biocompatible polymers produced by a variety of bacterial species under nutrientlimiting conditions. Biodegradable polymers have several advantages over the traditional plastics used presently. They have recently been FDA-approved for use in medical devices, increasing their potential for biomedical applications. PHAs are classified as short chain length PHAs and medium chain length PHAs. Depending on the application, a specific type of PHA can be identified and produced. Desired properties can also be achieved by making blends and composites of PHAs with organic and inorganic additives.
Coronary Artery Disease (CAD) remains the main killer disease caused by the deposition of plaque in the coronary artery. This results in obstructed blood and nutrient supply, leading to heart attack. Coronary stents are inserted to open the blocked artery and restore normal blood flow. Biodegradable coronary stents have the potential to address several limitations posed by the current metal and drug eluting stents. However, one of the most important challenges associated with biodegradable stents is their weak mechanical strength.
The focus of this study was to develop PHA-based materials with properties suitable for the development of biodegradable coronary stents. Novel composites of PHAs with acetylated bacterial cellulose were produced which exhibited increased mechanical strength, biocompatibility and biodegradability. Similarly, blends of two different types of PHAs with contrasting properties were developed as novel materials with intermediate properties. Proliferation studies using HMEC-1 (Human microvascular endothelial cell line) demonstrated high level of biocompatibility and possibility of endothelialisation. Also, controlled delivery of antithrombotic drugs was introduced using PHA-based microspheres for parenteral administration.