biomaterial

A biomaterial is a substance engineered to interface with biological systems for medical purposes. It may form part of a device, act as an implant, or serve as a scaffold that supports tissue repair. Biomaterials are selected for compatibility with the body and for their mechanical, chemical, and biological behavior in physiological conditions.

Biomaterials are often grouped as inert and biocompatible materials that remain in the body without provoking harm, and bioactive or biodegradable materials that interact with tissue or are gradually replaced. Common classes include natural polymers (for example collagen, chitosan), synthetic polymers (for example polylactic acid, polycaprolactone), ceramics (for example hydroxyapatite, bioactive glass), metals (for example titanium alloys), and composites that combine two or more constituents.

Critical properties include biocompatibility, which seeks to minimize toxicity and immune response; mechanical integrity to endure physiological loads; degradation or corrosion behavior for resorbable devices; and surface properties that influence protein adsorption, cell adhesion, and tissue integration. Sterilizability and shelf stability are also essential.

Manufacturing approaches include molding, extrusion, electrospinning, and additive manufacturing, often followed by surface modification or coating to tailor interactions with tissue. Applications span orthopedic and dental implants, cardiovascular devices, wound dressings, drug delivery systems, and tissue engineering scaffolds that guide regeneration.

Challenges include inflammation, infection, wear debris, and long-term stability. Regulatory oversight typically requires biocompatibility testing and preclinical and clinical evaluation according to international standards before medical use.