resorbability

Resorbability is the property of a material to be broken down and absorbed by the body's tissues and fluids after it has fulfilled its function. In medical contexts, resorbable materials are designed to provide temporary support, therapy delivery, or tissue guidance and then be eliminated or replaced by native tissue, reducing the need for surgical removal. Resorbability differs from general biodegradability by emphasizing removal within a living system and compatibility with physiological processes.

Degradation mechanisms vary by material class. Polymers such as polylactic acid (PLA), polyglycolic acid (PGA), and their copolymer PLGA primarily degrade through hydrolysis of ester bonds. The rate depends on molecular weight, crystallinity, hydrophilicity, and scaffold architecture; degradation products like lactic and glycolic acids are typically metabolized. Calcium phosphate and calcium sulfate ceramics resorb through dissolution and cellular remodeling, often being replaced by new bone. Resorbable metals (notably magnesium-based alloys) corrode in vivo, gradually losing strength with the release of ions; gas formation is a potential complication in some systems.

Common resorbable materials include PLA, PGA, PLGA, polycaprolactone (PCL), calcium phosphates and sulfates, and certain magnesium alloys. Applications span resorbable sutures and fixation devices, guided bone regeneration membranes, bone graft substitutes, and drug-delivery systems. The choice of material depends on desired resorption duration, mechanical requirements, and the expected tissue response.

Challenges include achieving predictable resorption kinetics, preserving mechanical integrity during healing, avoiding inflammatory or osteolytic reactions, and ensuring complete replacement by host tissue. Ongoing research aims to tailor degradation behavior through polymer chemistry, composite designs, and surface engineering.