Using two biocompatible elastic protein-based polymers (in viscolelastic gel and elastic sheet forms), the Phase I study demonstrated both materials to be highly effective in preventing adhesions to the spinal dura in the rabbit laminectomy model. The specific aims of Phase II are: 1) to identify the preferred membrane and/or gel configuration(s) of two biocompatible and resorbable polymer compositions for prevention of adhesions in a large animal laminectomy model, 2) to develop sensitive double radio-label standards for purification and a quality control protocol, 3) to utilize an adult sheep lumbar spine model with laminectomies performed at two non-contiguous levels (L3-L4 and L5-L6) allowing for a randomization of the polymer placement to surgical site, 4) to develop a mechanical test method for assessing the interface between the dura mater and the tested polymer and the epidural fibrotic tissue at the control site, and 5) to complete biocompatibility testing and prepare an IDE application for the preferred polymer(s) and state(s). The physical disability resulting from intervertebral disc herniation constitutes the third most common condition for worker disability in the U.S. An improved outcome of intervertebral disc laminectomy would improve the quality of life and restore function for many millions of disabled Americans. PROPOSED COMMERCIAL APPLICATION: Low back pain, for which intervertebral disc pathology is the major cause, is second only to the common cold for work absenteeism in the United States; it is reported to result in more productivity loss than any other medical condition and in an annual health care cost of $33 billion. Over four million cases of prolapsed intervertebral discs are reported annually in the U.S. Development of materials that would improve the outcome of intervertebral disc laminectomy would clearly be of commercial significance while impacting favorably on medical care costs.