Staphylococcus epidermidis Biofilm Formation on Traditional and Boron Metal Alloys

Higher biocompatibility and corrosion resistant biomaterials are more frequently being test-implanted for a wide range of purposes. However, surgery-related infection and implant microbe-colonization is generally the most common complication. When bacteria adhere to and proliferate on the biomaterial surface, the bacteria produce extracellular polymeric substances, primarily polysaccharides, which mediate cell-to-cell adhesion and form a biofilm. Our long-term goal is to extend the life of a prosthetic implant by identifying new metal alloys that are less susceptible to bacterial colonization. Using one of the major biofilm producing bacteria commonly found to colonize surgical implants, Staphylococcus epidermidis, we investigated the biocompatibility of novel metal alloys with regard to their susceptibility to biofilm propagation. The Experimental biometal alloys examined were stainless steel (SS), commercially pure titanium (CPTi), titanium alloy (Ti64), dental grade titanium (Ty) and titanium-boron metal alloys. Biofilm formation was analyzed using crystal violet staining and fluorescent microscopy. Ideal experimental conditions were obtained using flasks or a biofilm reactor. Biofilm reactor experiments were performed with (continuous culture) or without a constant infusion of growth media (batch culture) during biofilm formation. Results indicate that the Ty alloy permits less biofilm formation than traditional metals. Titanium-boron metal alloys, Ti64+0.04% B and Ti64+0.1% B, showed the least amount of biofilm compared to other metal alloys. Thus, we show that, compared to traditional metals such as stainless steel and pure titanium, the Ty, Ti64+0.04% B and Ti64+0.1% B alloys may be better alternatives as a modern prosthetic biometals.