Title: Developing materials for biomedical applications

By: Dr Phong Tran

Time: 10h AM, thursday, 16th April 2015

Place: 204, T2 building, VNU University of Science, 334th Nguyen Trai street, Hanoi

 

Abstract: 

This talk will highlight some of our research in developing materials for applications in medical implants, tissue engineering and drug delivery. The first example will discuss our study of using nanometer structured selenium as a promising material for implants in bone-cancer patients. Experimental results showed much promise for selenium nanocluster coatings on traditional implants. Experimental results of this study were complemented by computer simulation results of protein interactions on the nanometer rough surfaces created by selenium nanocluster coatings. Specifically, here it was demonstrated that selenium nanocluster coatings can be readily applied to bone implant metallic materials (titanium, stainless steel). Selenium nanoparticles were prepared using similar synthesis processes. Biological experiments showed that the selenium coatings on titanium promoted healthy bone cell functions. The increase in healthy bone cell functions on selenium coated surfaces was shown to be attributed to the increase in adsorption of fibronectin, one of the most important cell adhesive proteins that regulate interactions between bone cells and an implant surface. The increase in fibronectin adsorption was hypothesized to be due to the increase in root-mean-square (RMS) nanometer roughness of the selenium coated surfaces compared to the uncoated surfaces. To test this hypothesis, computer simulation was used to simulate the adsorption of fibronectin on the generated surfaces. Simulation results showed good agreement with experimental results. Moreover, results demonstrated decreased bone cancer cell functions while increased healthy bone cell functions on selenium coated implants. The decrease in cancerous bone cell growth was shown to be due to the release of selenium into cell culture media. Healthy bone cells were not affected by the released selenium in culture media. In the second example, I will discuss our study in using biomaterials as antimicrobial agents instead of antibiotics for biomedical applications. Antibiotics have successfully been used to treat infections. However, with the increasingly high number of bacteria that are resistant to multiple drugs, new type of antimicrobial agents are being developed. We focus on studying metallic materials that exhibit antimicrobial activities. First, I will discuss the antimicrobial activity of selenium coatings on polymeric substrates (including PVC, PU and silicone) against S. aureus, an important bacterium that infects all implants, especially catheters. I will then discuss our work in the new silver-based hybrid materials for controlled antimicrobial delivery. The findings from our studies suggest that these biomaterials have the potential to be used in a wide range of medical implants/devices for anti-cancer and/or antimicrobial purposes. Finally, I will present some of our new research direction in development of materials for soft/hard tissue regeneration such as for skin/fat/bone regeneration.

 

Short bio: 

Dr. Phong Tran is a Vice-Chancellor’s Research Fellow at The Institute of Health and Biomedical Innovation, Queensland University of Technology. Before taking up this position, he was a McKenzie Research Fellow in the Department of Chemical and Biomolecular Engineering, the University of Melbourne. Dr. Tran’s research has been focused on developing advanced materials for applications in medical devices, tissue regenerations and drug delivery. His research has attracted more than $500,000 in funding, resulted in more than 20 publications, 380+ citations, two international patents, two spin-off companies with commercial products available. Dr. Tran earned his PhD from Brown University (USA) in 2010 and migrated to Australia in 2011. He is now living in Brisbane with his wife and daughter.