We previously described a new method of producing antibacterial biomedical materials by the immobilization of lysozyme and a polypeptide antibiotic Polymyxin B onto the surface of collagen-synthetic polymer composite material. We have developed another method of producing antibacterial biomedical materials by mixing broad spectrum antibiotics, Cephalexin and Tobramycin, with the collagen membrane layer of collagen-synthetic polymer composite material. This antibiotic-mixed composite material showed excellent antibacterial activity against Staphylococcus aureus. The elution rate of antibiotics from the collagen membrane layer can be controlled considerably by glutaraldehyde cross-linking treatment of the collagen. This antibiotic-mixed composite material adapted better to the rabbit's dorsal subcutaneous tissue in the earlier stage of implantation than composite material without mixed antibiotic.
