Biopolymers in Medical Implants- a Brief Review Pdf

Polymer produced by a living organism

Biopolymers are natural polymers produced by the cells of living organisms. Biopolymers consist of monomeric units that are covalently bonded to form larger molecules. There are three main classes of biopolymers, classified co-ordinate to the monomers used and the construction of the biopolymer formed: polynucleotides, polypeptides, and polysaccharides. Polynucleotides, such every bit RNA and Deoxyribonucleic acid, are long polymers composed of thirteen or more^{[ clarification needed ]} nucleotide monomers. Polypeptides and proteins, are polymers of amino acids and some major examples include collagen, actin, and fibrin. Polysaccharides are linear or branched polymeric carbohydrates and examples include starch, cellulose and alginate. Other examples of biopolymers include natural rubbers (polymers of isoprene), suberin and lignin (complex polyphenolic polymers), cutin and cutan (complex polymers of long-chain fatty acids) and melanin.

Biopolymers have applications in many fields including the food manufacture, manufacturing, packaging, and biomedical engineering.^[1]

Biopolymers versus constructed polymers [edit]

A major defining departure betwixt biopolymers and synthetic polymers tin be found in their structures. All polymers are made of repetitive units called monomers. Biopolymers often have a well-divers structure, though this is non a defining characteristic (example: lignocellulose): The exact chemical composition and the sequence in which these units are arranged is called the primary construction, in the case of proteins. Many biopolymers spontaneously fold into characteristic compact shapes (run across besides "protein folding" besides as secondary construction and tertiary structure), which determine their biological functions and depend in a complicated mode on their primary structures. Structural biological science is the study of the structural properties of biopolymers. In contrast, nearly synthetic polymers' have much simpler and more random (or stochastic) structures. This fact leads to a molecular mass distribution that is missing in biopolymers. In fact, every bit their synthesis is controlled by a template-directed procedure 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 accept the same mass. This phenomenon is called monodispersity in contrast to the polydispersity encountered in synthetic polymers. As a issue, biopolymers have a dispersity of ane.^[2]

Conventions and nomenclature [edit]

Polypeptides [edit]

The convention for a polypeptide is to list its constituent amino acid residues as they occur from the amino terminus to the carboxylic acid terminus. The amino acid residues are always joined by peptide bonds. Protein, though used colloquially to refer to whatsoever polypeptide, refers to larger or fully functional forms and can consist of several polypeptide chains also as single chains. Proteins tin likewise be modified to include non-peptide components, such as saccharide bondage and lipids.

Nucleic acids [edit]

The convention for a nucleic acid sequence is to list the nucleotides as they occur from the five' end to the 3' terminate of the polymer chain, where v' and three' refer to the numbering of carbons around the ribose ring which participate in forming the phosphate diester linkages of the chain. Such a sequence is chosen the primary structure of the biopolymer.

Carbohydrate [edit]

Sugar polymers tin be linear or branched and are typically joined with glycosidic bonds. The exact placement of the linkage tin vary, and the orientation of the linking functional groups is besides important, resulting in α- and β-glycosidic bonds with numbering definitive of the linking carbons' location in the ring. In addition, many saccharide units can undergo diverse chemical modifications, such as amination, and can fifty-fifty grade parts of other molecules, such as glycoproteins.

Structural label [edit]

There are a number of biophysical techniques for determining sequence data. Protein sequence can be adamant past Edman degradation, in which the N-concluding residues are hydrolyzed from the chain ane at a time, derivatized, and so identified. Mass spectrometer techniques can besides be used. Nucleic acid sequence can exist adamant using gel electrophoresis and capillary electrophoresis. Lastly, mechanical backdrop of these biopolymers can often exist measured using optical tweezers or atomic strength microscopy. Dual-polarization interferometry can be used to measure the conformational changes or cocky-assembly of these materials when stimulated by pH, temperature, ionic forcefulness or other bounden partners.

Mutual biopolymers [edit]

Collagen:^[iii] Collagen is the primary structure of vertebrates and is the most abundant protein in mammals. Because of this, collagen is one of the most easily accessible biopolymers, and used for many research purposes. Because of its mechanical structure, collagen has high tensile force and is a non toxic, hands absorbable, biodegradable and biocompatible material. Therefore, it has been used for many medical applications such as in treatment for tissue infection, drug delivery systems, and gene therapy.

Silk fibroin:^[iv] Silk Fibroin (SF) is another protein rich biopolymer that tin be obtained from unlike silk worm species, such equally the mulberry worm Bombyx mori. In contrast to collagen, SF has a lower tensile force but has stiff agglutinative properties due to its insoluble and gristly protein limerick. In recent studies, silk fibroin has been constitute to possess anticoagulation properties and platelet adhesion. Silk fibroin has been additionally found to support stalk cell proliferation in vitro.

Gelatin: Gelatin is obtained from type I collagen consisting of cysteine, and produced past the partial hydrolysis of collagen from bones, tissues and skin of animals.^[v] There are two types of gelatin, Type A and Type B. Type A collagen is derived by acid hydrolysis of collagen and has xviii.5% nitrogen. Type B is derived by element of group i hydrolysis containing eighteen% nitrogen and no amide groups. Elevated temperatures cause the gelatin to melts and exists as coils, whereas lower temperatures result in coil to helix transformation. Gelatin contains many functional groups like NH2, SH, and COOH which allow for gelatin to exist modified using nanoparticles and biomolecules. Gelatin is an Extracellular Matrix poly peptide which allows it to be practical for applications such as wound dressings, drug commitment and gene transfection.^[5]

Starch: Starch is an inexpensive biodegradable biopolymer and copious in supply. Nanofibers and microfibers can be added to the polymer matrix to increase the mechanical properties of starch improving elasticity and strength. Without the fibers, starch has poor mechanical properties due to its sensitivity to wet. Starch being biodegradable and renewable is used for many applications including plastics and pharmaceutical tablets.

Cellulose: Cellulose is very structured with stacked bondage that result in stability and strength. The strength and stability comes from the straighter shape of cellulose caused by glucose monomers joined together by glycogen bonds. The straight shape allows the molecules to pack closely. Cellulose is very common in application due to its arable supply, its biocompatibility, and is environmentally friendly. Cellulose is used vastly in the form of nano-fibrils called nano-cellulose. Nano-cellulose presented at low concentrations produces a transparent gel fabric. This cloth can exist used for biodegradable, homogeneous, dumbo films that are very useful in the biomedical field.

Alginate: Alginate is the most copious marine natural polymer derived from brown seaweed. Alginate biopolymer applications range from packaging, fabric and food industry to biomedical and chemic engineering. The kickoff always application of alginate was in the form of wound dressing, where its gel-like and absorptive backdrop were discovered. When applied to wounds, alginate produces a protective gel layer that is optimal for healing and tissue regeneration, and keeps a stable temperature environment. Additionally, there have been developments with alginate as a drug delivery medium, as drug release rate can easily be manipulated due to a variety of alginate densities and fibrous composition.

Biopolymer applications [edit]

The applications of biopolymers can exist categorized under two main fields, which differ due to their biomedical and industrial use. ^[6]

Biomedical [edit]

Considering one of the main purposes for biomedical applied science is to mimic body parts to sustain normal trunk functions, due to their biocompatible properties, biopolymers are used vastly for tissue engineering, medical devices and the pharmaceutical industry.^[3] 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 bio-activity, and not-toxicity.^[7] Compared to synthetic polymers, which tin present various disadvantages similar immunogenic rejection and toxicity after degradation, many biopolymers are normally ameliorate with bodily integration as they besides possess more than complex structures, similar to the human body.

More than specifically, polypeptides like collagen and silk, are biocompatible materials that are being used in ground breaking inquiry, as these are inexpensive and hands attainable materials. Gelatin polymer is ofttimes used on dressing wounds where it acts as an adhesive. Scaffolds and films with gelatin allow for the scaffolds to agree drugs and other nutrients that can be used to supply to a wound for healing.

As collagen is one of the more popular biopolymer used in biomedical science, here are some examples of their utilise:

Collagen based drug commitment systems: collagen films deed like a bulwark membrane and are used to treat tissue infections similar infected corneal tissue or liver cancer.^[8] Collagen films have all been used for gene commitment carriers which can promote bone formation.

Collagen sponges: Collagen sponges are used every bit a dressing to treat burn down victims and other serious wounds. Collagen based implants are used for cultured peel cells or drug carriers that are used for burn down wounds and replacing skin.^[viii]

Collagen equally haemostat: When collagen interacts with platelets information technology causes a rapid coagulation of blood. This rapid coagulation produces a temporary framework then the gristly stroma can exist regenerated by host cells. Collagen based haemostat reduces blood loss in tissues and helps manage haemorrhage in cellular organs like 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 2d most abundant biopolymer in the world.^[3] Chitosan has many splendid characteristics for biomedical scientific discipline. Chitosan is biocompatible, information technology is highly bioactive, pregnant information technology stimulates a beneficial response from the body, it tin can biodegrade which tin 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 every bit drug delivery: Chitosan is used mainly with drug targeting considering information technology has potential to improve drug assimilation and stability. in improver Chitosan conjugated with anticancer agents can as well produce improve anticancer effects past causing gradual release of free drug into cancerous tissue.

Chitosan as an anti-microbial amanuensis: Chitosan is used to end the growth of microorganisms. It performs antimicrobial functions in microorganisms like algae, fungi, bacteria, and gram positive bacteria of unlike yeast species.

Chitosan composite for tissue engineering science: Blended power of Chitosan along with alginate are used together to course functional wound dressings. These dressings create a moist environment which aids in the healing process. This wound dressing is likewise very biocompatible, biodegradable and has porous structures that allows cells to grow into the dressing.^[3]

Industrial [edit]

Food: Biopolymers are being used in the food industry for things like packaging, edible encapsulation films and coating foods. Polylactic acrid (PLA) is very common in the nutrient manufacture due to is clear color and resistance to water. However, most polymers accept a hydrophilic nature and start deteriorating when exposed to moisture. Biopolymers are likewise being used equally edible films that encapsulate foods. These films can comport things like antioxidants, enzymes, probiotics, minerals, and vitamins. The nutrient consumed encapsulated with the biopolymer film can supply these things to the body.

Packaging: The most common biopolymers used in packaging are polyhydroxyalkanoate (PHA), polylactic acid (PLA), and starch. Starch and PLA are commercially available and biodegradable, making them a common pick for packaging. However, their barrier properties and thermal properties are not ideal. Hydrophilic polymers are not water resistant and let water to get through the packaging which can impact the contents of the package. Polyglycolic acrid (PGA) is a biopolymer that has dandy barrier characteristics and is at present beingness used to right the barrier obstacles from PLA and starch.

H2o purification: Chitosan has been used for water purification. Information technology is used every bit a flocculant that only takes a few weeks or months rather than years to dethrone into the surround. Chitosan purifies water by chelation. This is the process in which bounden sites along the polymer chain bind with the metal in the water forming chelates. Chitosan has been shown to be an excellent candidate for use in storm and waste product water handling.^[ix]

As materials [edit]

Some biopolymers- such equally PLA, naturally occurring zein, and poly-3-hydroxybutyrate can be used as plastics, replacing the need for polystyrene or polyethylene based plastics.

Some plastics are now referred to as being 'degradable', 'oxy-degradable' or 'UV-degradable'. This means that they suspension down when exposed to light or air, but these plastics are still primarily (as much as 98 per cent) oil-based and are not currently certified every bit 'biodegradable' under the Eu directive on Packaging and Packaging Waste (94/62/EC). Biopolymers will break down, and some are suitable for domestic composting.^[10]

Biopolymers (also called renewable polymers) are produced from biomass for use in the packaging industry. Biomass comes from crops such as carbohydrate beet, potatoes or wheat: when used to produce biopolymers, these are classified as not food crops. These can be converted in the following pathways:

Sugar beet > Glyconic acid > Polyglyconic acid

Starch > (fermentation) > Lactic acid > Polylactic acid (PLA)

Biomass > (fermentation) > Bioethanol > Ethene > Polyethylene

Many types of packaging can be made from biopolymers: nutrient trays, blown starch pellets for shipping fragile appurtenances, thin films for wrapping.

Environmental impacts [edit]

Biopolymers can be sustainable, carbon neutral and are always renewable, because they are made from found materials which can be grown indefinitely. These plant materials come from agronomical not nutrient crops. Therefore, the apply of biopolymers would create a sustainable manufacture. In contrast, the feedstocks for polymers derived from petrochemicals will somewhen deplete. In addition, biopolymers have the potential to cut carbon emissions and reduce CO_two quantities in the temper: this is considering the CO_two released when they degrade tin can exist reabsorbed past crops grown to supersede them: this makes them close to carbon neutral.

Biopolymers are biodegradable, and some are also compostable. Some biopolymers are biodegradable: they are broken down into CO_two and water past microorganisms. Some of these biodegradable biopolymers are compostable: they can be put into an industrial composting process and will break downwardly past ninety% within six months. Biopolymers that do this tin be marked with a 'compostable' symbol, nether European Standard EN 13432 (2000). Packaging marked with this symbol can exist put into industrial composting processes and will break downwardly within six months or less. An case of a compostable polymer is PLA film under 20μm thick: films which are thicker than that do not authorize every bit compostable, even though they are "biodegradable".^[11] In Europe there is a home composting standard and associated logo that enables consumers to identify and dispose of packaging in their compost heap.^[10]

See likewise [edit]

Biomaterials
Bioplastic
Biopolymers & Prison cell (journal)
Condensation polymers
Condensed tannins
Deoxyribonucleic acid sequence
Nutrient microbiology § Microbial biopolymers
Melanin
Non food crops
Phosphoramidite
Polymer chemical science
Sequence-controlled polymers
Sequencing
Modest molecules
Worm-like chain

References [edit]

^ Aksakal, R.; Mertens, C.; Soete, M.; Badi, N.; Du Prez, F. (2021). "Applications of Discrete Constructed Macromolecules in Life and Materials Science: Recent and Future Trends". Advanced Scientific discipline. 2021 (2004038): ane–22. doi:10.1002/advs.202004038. PMC7967060. PMID 33747749.
^ Stupp, Southward.I and Braun, P.Five., "Role of Proteins in Microstructural Control: Biomaterials, Ceramics & Semiconductors", Science, Vol. 277, p. 1242 (1997)
^ ^a ^b ^c ^d Yadav, P.; Yadav, H.; Shah, 5. G.; Shah, Yard.; Dhaka, G. (2015). "Biomedical Biopolymers, their Origin and Evolution in Biomedical Sciences: A Systematic Review". Journal of Clinical and Diagnostic Research. 9 (ix): ZE21–ZE25. doi:10.7860/JCDR/2015/13907.6565. PMC4606363. PMID 26501034.
^ Khan, Md. Majibur Rahman; Gotoh, Yasuo; Morikawa, Hideaki; Miura, Mikihiko; Fujimori, Yoshie; Nagura, Masanobu (2007-04-01). "Carbon cobweb from natural biopolymer Bombyx mori silk fibroin with iodine treatment" (PDF). Carbon. 45 (5): 1035–1042. doi:10.1016/j.carbon.2006.12.015. hdl:10091/263. ISSN 0008-6223.
^ ^a ^b Mohan, Sneha; Oluwafemi, Oluwatobi S.; Kalarikkal, Nandakumar; Thomas, Sabu; Songca, Sandile P. (2016-03-09). "Biopolymers – Application in Nanoscience and Nanotechnology". Recent Advances in Biopolymers. doi:ten.5772/62225. ISBN978-953-51-4613-1.
^ Aksakal, R.; Mertens, C.; Soete, Thousand.; Badi, Northward.; Du Prez, F. (2021). "Applications of Detached Synthetic Macromolecules in Life and Materials Science: Recent and Future Trends". Advanced Scientific discipline. 2021 (2004038): one–22. doi:10.1002/advs.202004038. PMC7967060. PMID 33747749.
^ Rebelo, Rita; Fernandes, Margarida; Fangueiro, Raul (2017-01-01). "Biopolymers in Medical Implants: A Brief Review". Procedia Engineering science. 3rd International Conference on Natural Fibers: Advanced Materials for a Greener World, ICNF 2017, 21–23 June 2017, Braga, Portugal. 200: 236–243. doi:10.1016/j.proeng.2017.07.034. ISSN 1877-7058.
^ ^a ^b Yadav, Preeti; Yadav, Harsh; Shah, Veena Gowri; Shah, Gaurav; Dhaka, Gaurav (September 2015). "Biomedical Biopolymers, their Origin and Evolution in Biomedical Sciences: A Systematic Review". Journal of Clinical and Diagnostic Research. 9 (9): ZE21–ZE25. doi:ten.7860/JCDR/2015/13907.6565. ISSN 2249-782X. PMC4606363. PMID 26501034.
^ Desbrières, Jacques; Guibal, Eric (2018). "Chitosan for wastewater treatment". Polymer International. 67 (1): vii–14. doi:x.1002/pi.5464. ISSN 1097-0126.
^ ^a ^b "NNFCC Renewable Polymers Factsheet: Bioplastics". Archived from the original on 2019-05-22. Retrieved 2011-02-25 .
^ NNFCC Newsletter – Outcome 5. Biopolymers: A Renewable Resource for the Plastics Industry

External links [edit]

NNFCC: The United kingdom's National Centre for Biorenewable Energy, Fuels and Materials
Bioplastics Magazine
Biopolymer group
Bio-Polym Blog
What's Stopping Bioplastic?

phippsapandi.blogspot.com

Source: https://en.wikipedia.org/wiki/Biopolymer