Other meanings of Biomaterial
Materials Science & Engineering
A biomaterial is any substance—natural or synthetic—engineered to interact with biological systems for medical purposes, whether diagnostic, therapeutic, or replacement of tissue or organ function.1 The field spans metals, ceramics, polymers, and composites, as well as biologically derived materials such as collagen and decellularized tissue. Biomaterials are distinct from mere biocompatible materials in that they are deliberately designed to elicit a controlled response in the host, often integrating with living tissue rather than simply being tolerated.2 Applications range from implantable devices and drug-delivery systems to tissue-engineered scaffolds and biosensors. The discipline draws on materials science, biology, chemistry, and medicine, and its evolution has been shaped by clinical needs, regulatory frameworks, and advances in molecular biology.
A biomaterial is defined by its intended function: to interact with biological systems for medical benefit. This includes materials used in implants (e.g., hip joints, stents), drug delivery systems, wound dressings, and tissue engineering scaffolds. The definition excludes materials that merely contact the body incidentally, such as packaging, unless they are engineered for a medical purpose.
The field is interdisciplinary, requiring knowledge of materials science, biology, and clinical medicine. Biomaterials can be classified by origin (natural, synthetic, or hybrid), by chemical composition (metals, ceramics, polymers, composites), or by degradability (biodegradable vs. biostable). The choice of material depends on the application, the required mechanical properties, and the host response.
The use of materials in medicine dates back to ancient civilizations, with early examples including gold and ivory for dental repairs and bone replacements.1 However, the modern era began in the mid-20th century with the development of synthetic polymers and the first successful hip replacement by John Charnley in the 1960s, which used a metal stem and a polyethylene cup. The 1970s and 1980s saw the rise of biodegradable sutures and controlled drug-release systems, while the 1990s brought tissue engineering, combining cells with scaffolds to regenerate organs.
Regulatory oversight has evolved in parallel. The U.S. Food and Drug Administration (FDA) established the first device regulations in 1976, and the International Organization for Standardization (ISO) developed standards for biocompatibility testing (ISO 10993). These frameworks ensure that biomaterials are safe and effective before clinical use.
Metals such as titanium and stainless steel are used for load-bearing implants due to their strength and corrosion resistance. Ceramics like alumina and zirconia offer wear resistance and are used in joint replacements and dental crowns. Polymers, including polyethylene, silicone, and polylactic acid, are versatile and can be tailored for degradation rates, making them ideal for sutures, drug delivery, and scaffolds.
Biologically derived materials, such as collagen and hyaluronic acid, are used in wound healing and cosmetic surgery. Decellularized tissue matrices provide natural scaffolds for organ regeneration. Advanced applications include smart biomaterials that respond to stimuli (e.g., pH, temperature) and bioactive materials that release growth factors to promote tissue integration.
Beyond mainstream implants, biomaterials have niche applications. For example, conductive polymers are used in neural interfaces to record brain signals, and shape-memory alloys like nitinol are used in self-expanding stents.2 In ophthalmology, intraocular lenses are made from acrylic or silicone, and in otology, cochlear implants rely on platinum electrodes.
Historically, the first clinical use of a synthetic biomaterial was the nylon suture in the 1940s, and the first vascular graft was made from Teflon in the 1950s.3 A lesser-known figure is William Kolff, who developed the first artificial kidney using cellophane tubing in the 1940s, paving the way for dialysis membranes. Today, biomaterials are also used in veterinary medicine and in the preservation of cultural artifacts, where enzymes are immobilized on materials for conservation.
This article focuses on the medical definition of biomaterials, excluding other uses such as in environmental science.
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