Biopolymer
Like other polymers, biopolymers consist of monomeric units that are covalently bonded in chains to form larger molecules.
Polysaccharides are linear or branched chains of sugar carbohydrates; examples include starch, cellulose, and alginate.
In addition to their many essential roles in living organisms, biopolymers have applications in many fields including the food industry, manufacturing, packaging, and biomedical engineering.
[1]biopolymers: Macromolecules (including proteins, nucleic acids and polysaccharides) formed by living organisms.
In fact, as their synthesis is controlled by a template-directed process in most in vivo systems, all biopolymers of a type (say one specific protein) are all alike: they all contain similar sequences and numbers of monomers and thus all have the same mass.
[citation needed] Polysaccharides (sugar polymers) can be linear or branched and are typically joined with glycosidic bonds.
In addition, many saccharide units can undergo various chemical modifications, such as amination, and can even form parts of other molecules, such as glycoproteins.
Protein sequence can be determined by Edman degradation, in which the N-terminal residues are hydrolyzed from the chain one at a time, derivatized, and then identified.
Lastly, mechanical properties of these biopolymers can often be measured using optical tweezers or atomic force microscopy.
Dual-polarization interferometry can be used to measure the conformational changes or self-assembly of these materials when stimulated by pH, temperature, ionic strength or other binding partners.
Because of its mechanical structure, collagen has high tensile strength and is a non-toxic, easily absorbable, biodegradable, and biocompatible material.
In contrast to collagen, SF has a lower tensile strength but has strong adhesive properties due to its insoluble and fibrous protein composition.
Gelatin is an Extracellular Matrix protein which allows it to be applied for applications such as wound dressings, drug delivery and gene transfection.
Nanofibers and microfibers can be added to the polymer matrix to increase the mechanical properties of starch improving elasticity and strength.
The strength and stability comes from the straighter shape of cellulose caused by glucose monomers joined by glycogen bonds.
Alginate biopolymer applications range from packaging, textile and food industry to biomedical and chemical engineering.
When applied to wounds, alginate produces a protective gel layer that is optimal for healing and tissue regeneration, and keeps a stable temperature environment.
[4] Many biopolymers can be used for regenerative medicine, tissue engineering, drug delivery, and overall medical applications due to their mechanical properties.
[7] 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.
Collagen based haemostat reduces blood loss in tissues and helps manage bleeding in organs such as the liver and spleen.
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 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.
[4] 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.
Polylactic acid (PLA) is very common in the food industry due to is clear color and resistance to water.
Biopolymers can be sustainable, carbon neutral and are always renewable, because they are made from plant or animal materials which can be grown indefinitely.
