Incorporating Bone Minerals into Orthopaedic Surfaces

DESCRIPTION (provided by applicant): Submerged Electro-Spark Deposition (SESD, US patent pending), developed at Advanced Surfaces And Processes, Inc., is a surface modification technique. Any conductive surface can be modified with regards to surface texture and chemical composition. The objective of the present proposal is to use SESD to incorporate appreciable amounts of bone mineral elements, i.e., calcium, phosphorus, or calcium phosphate, into surfaces of medical and surgical devices that would benefit from improved interactions with bone. The surface modification process will be concurrent with changes in surface texture. An increase in the affinity of bone cells to such surfaces could enhance osseo-integration, thereby promoting rapid healing, improve bonding, and enhancing implant longevity. Phase I of the project will systematically evaluate the proposed concept to identify a range of elemental compositions and surface texture parameters that may lead to rapid healing and improved osseo-integration. Specific aims include: 1) SESD process development to produce modified surfaces with sufficient variations in the quantities of calcium, phosphorus, or calcium phosphate; 2) metallurgical evaluations to measure elemental compositions; 3) biological evaluations including in vitro toxicity, bone cell attachment, growth and differentiation experiments, and pilot in vivo animal tests, comparing the leading candidate, on healing and osseo-integration. Based on the Phase I results, a Phase II application would include process optimization, modification of clinical devices for animal osseo-integration tests, and evaluation of biomechanics. The clinical potential of the technology is significant. One of the continuing pursuits in orthopaedics is to develop prosthetic, spinal and dental implants that exhibit superb fixation and result in extended implant longevity. The SESD process avoids many of the limitations present in other surface coating technologies and offers a new technologic platform that could develop into a viable commercial venture for Advanced Surfaces and Processes, Inc.