About Biomaterials and Bioengineering
Technological advancements are underway for the development of continuous monitoring and regulating glucose levels by the implantation of sensor chips. Lab-on-a-chip technology is expected to modernize the diagnostics and make it more easy and regulated. Other area which can improve the tomorrow’s healthcare is drug delivery. Micro-needles have the potential to overcome the limitations of conventional needles and are being studied for the delivery of drugs at different location in human body. There is a huge advancement in the area of scaffold fabrication which has improved the potentiality of tissue engineering. Most emerging scaffolds for tissue engineering are hydrogels and cryogels. Dynamic hydrogels have huge application in tissue engineering and drug delivery. Furthermore, cryogels being supermacroporous allow the attachment and proliferation of most of the mammalian cell types and have shown application in tissue engineering and bioseparation.
From healthcare perspective, biomaterials can be divided in following categories: (1) Synthetic (metals, polymers, ceramics, and composites); (2) Naturally derived (animal and plant derived); (3) Semi-synthetic or hybrid materials. All these types of biomaterials are being used in healthcare from a long time period, but ensuing developments have enhanced their utility in healthcare. Metals are the class of materials those are widely used for load bearing applications. Some of the examples include wires and screws to fracture fixation plates and artificial joints. During hip replacement femoral components are usually manufactured from Co-Cr-Mo or Co-Ni-Mo alloys or titanium alloys. Polymers as implants or biomedical devices are used as facial prostheses, tracheal tubes, kidney and liver parts, heart components, etc. Ultrahigh molecular weight polyethylene (UHMWPE) has shown application in knee, hip and shoulder joints.
Ceramics have revealed application as dental implants or filling materials. As ceramics have poor fracture toughness they have limited applications as load bearing materials. Composite materials are extensively used for prosthetic limbs, due to the combination of low density and high strength. Few types of composite materials like bisphenol A-glycidyl-quartz/silica filler and polymethyl methacrylate-glass filler are widely being used for dental restorations. Naturally derived polymers like collagen, gelatin, alginate, hyaluronic acid, etc are widely used in the areas of healthcare for the fabrication of three-dimensional (3-D) scaffolds to support cell growth and proliferation. Such 3-D cell seeded scaffolds mimic the native host tissue so has significant applicability in the area of regenerative medicine. As naturally derived biomaterials have limited mechanical strength it restricts their applications at load bearing regions. So such materials are being modified chemically to improve their mechanical properties. Examples include collagen chains modified with lysine and hydroxyl-lysine, PEGylated fibrinogen (PF), etc.
First generation of biomaterials evolved during 1960s and 1970s for their application as medical implants. Basic goal during the fabrication of these biomaterials was to maintain a balance between physical and mechanical properties together with minimal toxicity to host tissue. Ideal properties of the first generation biomaterials sought by surgeons were (1) appropriate mechanical properties; (2) resistance to corrosion in aqueous environment; and (3) should not elicit toxicity or carcinogenicity in living tissue. But second generation biomaterials were developed to be bioactive. Further developments with the biomaterial technology are now translating into the expansion of third generation biomaterials those can stimulate specific cellular response. Examples include bioactive glass (3rd generation) and porous foams those are designed in a manner that they activate genes those can stimulate regeneration of living tissues. Efforts are also being made to develop scaffolding materials those possess nanoscale features in order to mimic the native extracellular matrix of the host.
Currently major focus of the researchers is the development of artificial tissues (as biomaterials) those have architectural features same as the natural counterpart. Development and use of biomaterials is expected to augment in coming years. New prognostic methods are being developed and are becoming available to assist the progress of innovative approaches for an affordable healthcare.