Biomedical applications of biopolymeric materials

Turmeric oil encapsulated in alginate beads
Sodium alginate beads containing turmeric oil
Biopolymers are produced by living organisms. Their characteristics depend majorly on their structure. Most of them have to be modified in order to enhance their properties. This involves compound reaction procedure, accompanied by long reaction times. Biopolymers are widely used for biomedical applications such as wound dressing and drug delivery due to their antibacterial and antifungal properties.
Chitosan film
Chitosan film

A three-year study is being conducted at TERI aims at investigating the microwave assisted grafting of biopolymeric materials like chitosan, and alginate capsules loaded with herbal extracts with biocompatible material like 2-hydroxyethyl methacrylate (HEMA). As part of this study, sponsored by the Council of Scientific and Industrial Research (CSIR), cross linking of biopolymeric materials was carried out by exposing them to radiations in a microwave reactor, customized to suit the reaction conditions.

Turmeric oleoresin encapsulated in alginate beads
Sodium alginate beads containing turmeric
The team was successful in the synthesis of chitosan and alginate grafted biocompatible materials like chitin or chitosan, using microwave irradiation. The resultant product was found to be suited for wound dressing applications. The product contains herbal extracts, and when it comes in contact with human body fluid, it swells and slowly releases the herbal extracts which have antiseptic and anti-bacterial properties, thereby aiding wound healing.

Neem oil encapsulated in alginate beads
Sodium alginate beads containing neem seed

The existing products used in wound dressing consist of chemicals which may have side effects. The product obtained from this project will be ideally suited for wound dressing applications since chitin-based derivatives, alginate, and 2-hydroxyethyl methacrylate (HEMA) are known for their antibacterial and biocompatible characteristics. The inclusion of herbal extracts will further aid and accelerate external wound healing. These capsules will be impregnated in grafted chitosan films which can be directly applied to the site of injury. However, the wound dressing material can only be used for minor wounds but not for critical injuries.

As this project reaches its completion, we can look forward to possible applications in pesticides/fertilizers domain as well. Encapsulation of pesticides/fertilizers can be used for slow release into the soil. Since the product is still under development, the biocompatibility and cytotoxicity aspects will be studied in the next phase of the work, when the product is completely developed.

Sponsor: Council of Scientific and Industrial Research (CSIR)
Duration: 3 years
Key Stakeholder / Beneficiaries: Biochemical industry
  • To synthesize chitosan/chitin and alginate grafted biocompatible materials, like HEMA, using microwave irradiation;
  • Encapsulation of turmeric, neem seed oil, calendula oil, or marigold extract in cross-linked microcapsules;
  • Preparation of films of chitosan loaded with capsules of herbal extracts and reinforced with chitin fibers to enhance their mechanical strength.

What are biopolymers?

Biopolymers are organic polymers. They have been in existence since billions of years. Starch, proteins, DNA, and RNA, are well known biopolymers which constitute our bodies and the whole of biosphere. A polymer is made up of smaller units called monomers. Monomers are converted into polymers by a process called polymerization.

Biopolymers are polymers that are biodegradable. The input material for the production of these polymers may can be renewable (plant or animal product based) or artificial/synthetic. Biopolymers can be produced without toxic byproducts and they degrade quickly. Hence, they leave marginal human footprint on the environment. They have a well-defined structure and an evenly distributed molecular weight.

Biopolymers have complex folding patterns. Under a powerful microscope, biopolymers look like a ball of string.

Posted on: 11 August 2011