The overall goal of this project is to develop thin, multifunctional films on metal alloy implant materials. The design of these films is to resist the non-specific adhesion of protein, bacteria and cells while delivering biologically active moieties on the surface.
The specific aims outlined below detail the grant's focus on controlling the surface of the implant materials, stainless steel 316L, Ti-6Al-4V, and Co-Cr-Mo, to prevent biofilm formation and thus prevent costly infections. The work proposed here is a collaboration between a surface chemist, Dr. Ellen Gawalt and a biofilm expert, Dr. Luanne Hall-Stoodley. The expertise of both people is required for success of this project. The expertise and equipment provided by Dr. Hall-Stoodley cannot be found at Duquesne University. Additionally, the students working on the project will gain educationally by interacting with both chemists and biologists on this interdisciplinary project.
Specific Aim I : Develop robust organic surface chemistry that will act as a flexible platform for controlling the interfacial region between implants and tissues. Chemical modification of the metal surface by self-assembled monolayers will allow for control of the interface through the presentation of desired moieties at the surface, including peptides, proteins and antibiotics. The focus of this aim is to develop, characterize and understand surface chemistry that provides comprehensive, strongly adhered monolayer coverage of the stainless steel 316L, Ti-6Al-4V, and Co-Cr-Mo oxide surfaces.
Specific Aim II : Mitigate non-specific bacteria adhesion and subsequent biofilm formation through chemical modification of alloy implant surfaces. Thus far no monolayer system has been developed that successfully renders these alloy oxide surfaces inert to the non-specific adhesion of protein, bacteria or human cells. The tail groups presented at the surface will be varied to render the surface inert to bacterial adhesion and subsequent biofilm formation. Biofilm development will be tested by using a model bacterium, Staphylococcus epidermidis and methods that assess biofilm formation on surfaces including counting, imaging and kinetic analysis over short and long time periods for quantification of in situ data to provide a sensitive, yet robust statistically based comparison of different monolayers.
This project is designed to reduce the number of costly implant infections through chemical modification of implant surfaces which will resist the formation of biofilms. These biofilms can cause implant infections, which currently affect 1 million patients per year in the United States.
| Kruszewski, Kristen M; Nistico, Laura; Longwell, Mark J et al. (2013) Reducing Staphylococcus aureus biofilm formation on stainless steel 316L using functionalized self-assembled monolayers. Mater Sci Eng C Mater Biol Appl 33:2059-69 |
| Kruszewski, Kristen M; Gawalt, Ellen S (2011) Perfluorocarbon thin films and polymer brushes on stainless steel 316 L for the control of interfacial properties. Langmuir 27:8120-5 |
| Lim, Min Soo; Smiley, Katelyn J; Gawalt, Ellen S (2010) Thermally driven stability of octadecylphosphonic acid thin films grown on SS316L. Scanning 32:304-11 |
| Raman, Aparna; Quiñones, Rosalynn; Barriger, Lisa et al. (2010) Understanding organic film behavior on alloy and metal oxides. Langmuir 26:1747-54 |
| Raman, Aparna; Gawalt, Ellen S (2010) Reduction of 3T3 Fibroblast Adhesion on SS316L by Methyl-Terminated SAMs. Mater Sci Eng C Mater Biol Appl 30:1157-1161 |
