Introduction to Biopolymers

Biopolymers are defined as polymers that are produced by living organisms and constitute a special class of polymers that are biodegradable in nature. Biopolymers that are employed for medical applications are classified as `advanced medical biopolymers'.

The use of biopolymers in the medical field is a relatively new and emerging area of research. For medical applications, apart from the fact that biopolymers are biodegradable, research is ongoing into the various other favourable aspects of biopolymer properties. Such properties would be:

• biocompatibility
• higher retention duration within the body
• degradation by natural mechanisms that occur within the body
• non-cytotoxic
• exhibiting immuno-tolerance

Advances in genetic engineering and recombinant DNA technology have given scientists the flexibility to modify the naturally derived polymers to befit a medical application. Medically biopolymers have tremendous potential in diverse areas of medical research including; drug delivery, medical devices and tissue engineering. A brief overview of the some of the uses and potential applications for biopolymers in the medical sector is as given below:

Medical Device Biopolymers

Medical Device Biopolymersare widely used to develop biopolymer-based biomaterials in fields such as orthopaedics, cardiology, ophthalmology and general surgery. They are used to develop a range of simple to more complex medical devices. Some of the devices that could be developed using biopolymers are: dental implants, corneal implants and artificial corneas, intraocular lenses, bone defect fillers, fracture fixation plates, artificial tendons and ligaments, hip and knee joint replacements, vascular grafts, heart valves, pacemakers, artificial heart and ventricular assist device components, stents, balloons, and blood substitutes.

Tissue Engineering Biopolymers

Tissue Engineering Biopolymers are employed for tissue regeneration, restoration and repair and to improve tissue function. They can be used to develop scaffolds for tissue engineering, which would supply nutrients and other growth factors and aid the growth of tissues. Some of the tissue engineering applications of biopolymers include: tissue screws and tacks, burn and wound dressings, artificial skin and tissue adhesives and sealants. There are many uses currently filled by medical grade plastics that could be substituted by similar biopolymers which would generally cause fewer adverse reactions in patients. Skin rejuvenation and cosmetic tissue repair using tissue compatible biopolymers are of remarkable commercial interest. One such important natural molecule is hyaluronic acid.