Why in news?
Biomaterials have attracted global attention in recent years because they offer solutions to challenges in healthcare, sustainability and manufacturing. Researchers are developing biodegradable plastics to replace petroleum‑based polymers, designing scaffolds for tissue regeneration and creating eco‑friendly materials for vehicles and consumer goods. Understanding the different classes of biomaterials helps in appreciating their potential and limitations.
Background
A biomaterial is any substance – natural or synthetic – that has been engineered to interact with biological systems for a medical or industrial purpose. These materials must be biocompatible, meaning they do not provoke harmful reactions when in contact with living tissues. Early biomaterials included metals used to repair broken bones, but the field now spans polymers, ceramics, composites and natural substances used in implants, drug delivery systems and regenerative medicine. Biomaterials also play a role in sustainable packaging and lightweight components for vehicles and aircraft.
Classification by source
- Natural biomaterials: Derived from biological sources such as proteins (e.g., collagen, gelatin), polysaccharides (e.g., cellulose, chitosan) and biopolymers like silk. These materials are often biodegradable and have intrinsic biocompatibility.
- Synthetic biomaterials: Man‑made materials engineered to mimic properties of natural tissues. They include metals (stainless steel, titanium alloys), ceramics (alumina, zirconia, hydroxyapatite, bioglass) and polymers (polyethylene, polylactic acid, polymethyl methacrylate). Synthetic biomaterials offer greater control over mechanical strength, degradation rate and processing.
Classification by bioactivity
- Bioinert: Materials that elicit minimal reaction from surrounding tissues. Examples include stainless steel, titanium and alumina. A thin fibrous capsule may form around the implant, but there is little bonding with bone.
- Bioactive: Materials that interact with tissue and form a chemical bond. When implanted, they develop a layer of calcium phosphate similar to bone, promoting strong integration. Examples include hydroxyapatite, certain glass–ceramics and bioglass.
- Bioresorbable: Materials that degrade over time and are replaced by natural tissue. They are used when temporary support is required, as in dissolvable sutures or bone screws. Examples include tricalcium phosphate and polylactic–polyglycolic acid copolymers.
Applications
- Medical implants: Orthopaedic joints, dental implants and cardiovascular stents rely on biocompatible metals and ceramics. Bioresorbable screws and plates support healing bones without the need for removal.
- Tissue engineering and regenerative medicine: Scaffolds made from natural or synthetic polymers provide a three‑dimensional framework for cells to grow and form tissues such as skin, cartilage or even organs. Biomaterials can also deliver growth factors and drugs to promote healing.
- Drug delivery: Hydrogels, nanoparticles and biodegradable polymers are used to release medicines at controlled rates to maximise therapeutic effects and minimise side‑effects.
- Sustainable manufacturing: Bio‑based plastics and composites help reduce dependence on fossil fuels. Drop‑in bio‑plastics, such as bio‑PE or bio‑PET, are chemically identical to their petroleum counterparts and can be processed in existing infrastructure. Novel bio‑plastics like polylactic acid (PLA) or polyhydroxyalkanoates (PHA) offer new functionality and are biodegradable.
- Transportation and consumer goods: Natural fibres and bio‑composites make vehicles lighter and more fuel‑efficient. In everyday products, bio‑based materials provide eco‑friendly alternatives in textiles, packaging and household items.
Significance
- Healthcare innovation: Biomaterials improve patient outcomes by enabling minimally invasive surgeries, regenerative therapies and customised implants.
- Environmental benefits: Bio‑based and biodegradable materials reduce plastic waste and carbon emissions, supporting circular economies.
- Cross‑disciplinary research: Advances in chemistry, materials science and biology are unlocking new properties and applications, underscoring the need for interdisciplinary collaboration.
Sources: The Hindu
