(500d) Breath Figure Thin Films of Biodegradable Polymers for Controlled Antibiotic Release

Biodegradable polymeric materials are of significant interest in the design of controlled drug release system. We describe the breath figure method^1,2 of synthesizing highly porous poly lactic-co-glycolic acid (PLGA) films for the controlled release of antibiotics, with the specific application of developing surgical coatings with controlled antibiotic release. The breath figure method is a versatile and simple way of generating porous structures by evaporating solutions of a simple coil-like polymer in a volatile solvent in a humid environment. Condensation of water droplets on the polymer due to the cooling produced by evaporating solvent leads to patterned pore formation upon eventual droplet removal. The facile removal of the pore template is a specifically appealing aspect of breath film technology. Coupling spin coating with breath figure generation leads to extremely thin PLGA films (20 microns) with a characteristic breath figure mesh structure.

Techniques to coat surgical meshes with such films are described. The focus of the research is to develop infection resistant biological meshes to be used in hernia surgery. The release characteristics of antibiotics (vancomycin and gentamycin) in such breath figure coatings are compared to release characteristics of flat nonporous films. High resolution scanning electron and atomic force microscopies are used to characterize the degradation of PLGA breath figure films on tissue based surgical coatings. Antibiotic disk susceptibilities are measured using the Kirby-Bauer disk-diffusion method with test organisms. We also hope to describe in-vivo testing of such coated implants in animal models.

References:

1) Mohan Srinivasarao, et al, Science, 292, 79(2001)

2) U.H.F.Bunz, Advanced Materials, 18, 973-989(2006)