Objective: The complications related to implant associated infections in post-angioplasty patients were considered to increase due to biofilm formation. Methods:Genes responsible for the biofilm formation in the target organisms was investigated in the present study. The presence of the intercellular adhesion biofilm genes (icaA, icaB and icaD) was determined by the Polymerase Chain Reaction method. As preliminary investigations, standard tests, exit-site challenge test and microtitre plate method were used to study the biofilm efficiency of five different test organisms.Results: Exit-site challenge test, was used to identify the ability of test organisms to grow on a bio-materials used in the study. Among the five selected test organisms, Staphylococcus aureus showed the highest ability to colonize the stent materials with in 24h to 48h. In microtitre plate method, Staphylococcus aureus and Staphylococcus epidermidis showed high biofilm forming index values of 0.29 and 0.27 respectively. Biofilm gene studies using PCR revealed the presence of all the three ica genes (Ica A, Ica D and, Ica B) in Staphylococcus aureus. The present research finding has great significance in the treatment to implant associated infections. Conclusions:The results suggest that the virulence factors contributing to the development of infections can be revealed by understanding the presence of biofilm expression genes in the target organisms. This would also prevent dissemination of virulent bacteria in the health care centre; method also considered significant to detect healthy carriers of slime-producing staphylococci.

Restenosis and biofilm formation during coronary stent implantation were considered to increase the complications of cardiovascular disease. To prevent these dual problems, drug-eluting stents coated with crystallized drug-polymer mixtures (Rapamycin-Polyvinyl pyrrolidone) were developed and its efficacy was investigated in the present study. Single layer coating using seeding and crystallization of drug-polymer mixture on the stent surface were carried out for effective drug delivery at the target site. Efficacy of rapamycin release concentration from the coated drug-eluting stents for the prevention of restenosis using High performance liquid chromatography was determined. Antibacterial activity of the drug-eluting stents against biofilm organisms was simultaneously studied. High performance liquid chromatography established the efficiency of modified coating technique and controlled release of rapamycin from drug-polymer mixture. Antibacterial activity of drug-eluting stents showed maximum inhibitory zone of 31.3mm against Staphylococcus aureus for 2X crystallized rapamycin coated stents. SEM images of rapamycin coatings on the stents exhibits extremely large uniform and continuous layer of parallelogram shaped rapamycin crystals in drug loaded stents. The sustained release of drugs fulfilled the primary aim of developing an anti-infective method for post-operative infection caused by biofilm organisms and also the prevention of restenosis.