Osteomyelitis is a serious orthopedic problem, and its prevention or treatment using systemic antibiotics is prone to complications and often unsuccessful. The use of polymethylmethacrylate beads or bone cement to deliver drug directly to bone sites does reduce the incidence of post- operative bone infections, but these non-porous polymers are inefficient drug delivery vehicles, and because they are non-biodegradable materials they cannot be used where bone regrowth is desired. BIOTEK has recently discovered new methods which for the first time allow medical cements to be prepared from porous, biodegradable, FDA-approved polylactide- coglycolide. These new cements are produced using harmless softening and sintering agents, and their workability, cure time, shrinkage, porosity, and strength are subject to control. Phase I will prepare and characterize biodegradable cements for use in bone cavities; introduce a prototype antibiotic, tetracycline, to demonstrate sustained drug delivery in vitro; and test the most promising formulation in vivo in a rat bone regrowth model.
The first target of biodegradable PLG cements will delivery of antibiotics to bone cavities, but they also hold promise for use in other anatomical sites, and as aids in the manufacture of versatile drug-delivery implants. As bone cements these new materials can also be expected to lead to products which dispense growth hormones and healing factors as well as antibiotics. The humane and commercial benefits associated with bone cements alone should more than repay the required Phase I and II investment.
