text: Because one of the main purposes for biomedical engineering is to mimic body parts to sustain normal body functions, due to their biocompatible properties, biopolymers are used vastly for tissue engineering, medical devices and the pharmaceutical industry. Many biopolymers can be used for regenerative medicine, tissue engineering, drug delivery, and overall medical applications due to their mechanical properties. They provide characteristics like wound healing, and catalysis of bioactivity, and non-toxicity. Compared to synthetic polymers, which can present various disadvantages like immunogenic rejection and toxicity after degradation, many biopolymers are normally better with bodily integration as they also possess more complex structures, similar to the human body.
  More specifically, polypeptides like collagen and silk, are biocompatible materials that are being used in ground-breaking research, as these are inexpensive and easily attainable materials. Gelatin polymer is often used on dressing wounds where it acts as an adhesive. Scaffolds and films with gelatin allow for the scaffolds to hold drugs and other nutrients that can be used to supply to a wound for healing.
  As collagen is one of the more popular biopolymers used in biomedical science, here are some examples of their use:
  Collagen based drug delivery systems: collagen films act like a barrier membrane and are used to treat tissue infections like infected corneal tissue or liver cancer. Collagen films have all been used for gene delivery carriers which can promote bone formation.
  Collagen sponges: Collagen sponges are used as a dressing to treat burn victims and other serious wounds. Collagen based implants are used for cultured skin cells or drug carriers that are used for burn wounds and replacing skin.
  Collagen as haemostat: When collagen interacts with platelets it causes a rapid coagulation of blood. This rapid coagulation produces a temporary framework so the fibrous stroma can be regenerated by host cells. Collagen based haemostat reduces blood loss in tissues and helps manage bleeding in organs such as the liver and spleen.
  Chitosan is another popular biopolymer in biomedical research. Chitosan is derived from chitin, the main component in the exoskeleton of crustaceans and insects and the second most abundant biopolymer in the world. Chitosan has many excellent characteristics for biomedical science. Chitosan is biocompatible, it is highly bioactive, meaning it stimulates a beneficial response from the body, it can biodegrade which can eliminate a second surgery in implant applications, can form gels and films, and is selectively permeable. These properties allow for various biomedical applications of chitosan.
  Chitosan as drug delivery: Chitosan is used mainly with drug targeting because it has potential to improve drug absorption and  stability.  In addition, chitosan conjugated with anticancer agents can also produce better anticancer effects by causing gradual release of free drug into cancerous tissue.
  Chitosan as an anti-microbial agent: Chitosan is used to stop the growth of microorganisms. It performs antimicrobial functions in microorganisms like algae, fungi, bacteria, and gram-positive bacteria of different yeast species.
  Chitosan composite for tissue engineering: Chitosan powder blended with alginate is used to form functional wound dressings. These dressings create a moist, biocompatible environment which aids in the healing process. This wound dressing is also biodegradable and has porous structures that allows cells to grow into the dressing. Furthermore, thiolated chitosans (see thiomers) are used for tissue engineering and wound healing, as these biopolymers are able to crosslink via disulfide bonds forming stable three-dimensional networks.