The composite and hybridization approach in developing new biomaterials

Abstract

In the early part of the last century, various materials were used as “biomaterials” for human body repair. The modern-day biomaterials development started in the middle of the last century when it was realized that borrowing engineering materials to use them in the medical field had insurmountable problems and that new materials must be developed specifically for medical applications. Most human body tissues, such as bone, are natural composite materials. In bone, two levels of composite structure are identified: first, the bone apatite reinforced collagen forming individual lamella at the nm to  m scale and, second, osteon reinforced interstitial bone at the  m to mm scale. With a biological template such as bone, the R & D in biomedical composites for hard tissue replacement by mimicking the bone apatite-collagen structure was started in the 1980s. Many researchers around the world have since adopted this composite approach and investigated a variety of bioactive bioceramic-polymer composites of various characteristics in order to meet clinical requirements. Through careful materials design, this biomimicking, composite approach has also been used in developing ceramic-matrix and metal-matrix composites for human tissue repair in major load-bearing parts of the body. The huge advantages of using biodegradable biomaterials for human tissue repair to eliminate second surgeries have led to the extensive exploration of biodegradable composites. These biomedical composites (biodegradable or non-biodegradable) can be used in areas such as orthopaedics and dentistry. Since more than two decades ago, great interest in tissue engineering has led to wide investigations into composite and/or hybridized tissue engineering scaffolds. These scaffolds, with careful design and manufacture, possess multiple functions and can significantly enhance tissue regeneration. Advanced composite or hybridized scaffolds are now used for regenerating tissues such as blood vessels, cartilage and peripheral nerve. On the other hand, in recently emerging areas such cancer nanotechnology, advanced theranostics, which are nanodevices for cancer detection and treatment, are mostly based on nanocomposite particles. These new theranostics have multiple capabilities and provide combined therapies for cancer treatment. This talk will give an overview of our efforts in the R & D of biomaterials using the composite and hybridization approach and discusses important factors affecting the performance of these materials.