**2. Medical applications**

Due to some side effects and toxicity, pharmaceutical and medical products made from chemicals have become an inseparable problem of the human health care system. The use of natural polymers in pharmaceuticals and medicine is comparable to synthetic polymers, and they are also widely used in the food and cosmetic industries. Currently, due to the negative impact and undesirable performance of synthetic polymers, they are looking for solutions to replace them [6, 9]. Biopolymers have been intensively studied primarily due to their biocompatibility, biodegradability, and ease of displacement and processing, and they have been used in drug delivery and medical applications. Known natural biopolymers used in pharmaceuticals and other fields are chitosan, carrageenan, ispaghula, acacia, agar, gelatin, guar gum, karaya gum (sterculia gum), and alginate. These natural polymers are used in the pharmaceutical industry as emulsifiers, adjuvants, and adhesives in packaging and in the development of cosmetic products [10, 11]. In the studies conducted on alginates as natural polymers, according to their unique properties and beneficial biological activities, they have been more and more considered attractive compounds in the biomedical and pharmaceutical fields. According to these studies, their use has led to biotechnological developments, such as being suitable as a matrix for 3D tissue cultures, antimicrobial and viral agents, and helping antibiotics, in the treatment of diabetes, obesity, or neurological diseases (**Table 1**). Sodium and calcium alginates are two natural polymers widely used in pharmaceutical and medical fields and have become common in most countries [12, 13].

Other usages of alginate and its products in treating diverse diseases, including skin inflammations, tumors, osteoporosis, etc., have increased significantly. One of the applications of alginate in medicine is its use in wound dressing. The sodium


#### **Table 1.**

*Applications of alginate in the fields of medicine.*

alginate present in the dressing reacts with the wound fluid and retains the wound humid, and speeds up the healing process. Also, ions, such as calcium and other compounds can be used in dressings with alginate for faster wound amelioration. Immobilizing nanoparticles is a proper approach to their crucial role as agents against microbial infections without extreme aggregation. Due to its close relevance with the biomedical field, sodium alginate was specially selected to stabilize and bind the synthesized Nano Zink Oxide to cellulose fiber. Also, adding some compounds to alginate dressing, such as silver and some antimicrobial agents, excludes microbial putridity of wounds (**Figure 2**) [14, 15].

Alginate-based hydrogels transfer various angiogenic molecules due to their special characteristics, such as biocompatibility, hydrophilic properties, cheapness, non-toxicity to the body, and accessible shaping properties. This case is used to treat patients with restricted or blocked blood flow [16]. Using alginate hydrogel capsules for tissue engineering applications has increased widely. These hydrogels can transfer inducing factors and needed substances for the repair of bone and cartilage tissues due to the property of adhesion to target tissue ligands, ease of transfer, and maintaining the stability of transfer substances. Alginate-based gels have been used for their ability to regenerate and engineer a variety of tissues, including skeletal muscles, the pancreas, nerves, and the liver. In researchers' studies, chitosan nanoparticles were produced on liposomes for growth factor delivery [17, 18].

Based on successful experiments, it has been shown that alginate microparticles can easily be transferred to the cellular and subcellular structures in the epithelium of the stomach and intestines and subepithelial areas due to their adhesive properties, increased release time, and small particle sizes. Moreover, they are suitable for mucosal vaccination and drug transfer to the bloodstream. Oral administration of alginate does not stimulate many immune responses, unlike intravenous forms, and alginate has been reported to be non-toxic and biodegradable when given orally. This feature is used in the pharmaceutical industry to enhance drug resistance and hold the properties of molecules in the oral cavity and digestive system. These findings verify the ability of alginate nanoparticles to attach to the intestinal barrier and reach the bloodstream, which was the opposite of other combinations that remained mainly in the intestinal mucosa [19]. Alginate nanoparticles due to their ability to penetrate into the deep mucous layers of the stomach has been used to release amoxicillin in the treatment of *Helicobacter pylori* infection that settles in the deep mucous layers of the stomach. The transfer of anti-cancer, antimicrobial, and antibiotic drugs is achievable using these properties of alginate nanoparticles. Alginate gels are usually nanoporous, which leads to the fast diffusion of small molecules in the gel, so they are helpful for the delivery of a variety of intravenous drugs with low molecular weight [20, 21].

**Figure 2.** *Application of alginate in wound healing dressing.*

#### *Applications of Alginate in the Fields of Research Medicine, Industry and Agriculture DOI: http://dx.doi.org/10.5772/intechopen.110209*

Probiotics are tiny, live, and active microscopic organisms, and eating them modifies the microbiome of our digestive tract for better health. We call them beneficial intestinal bacteria most of the time. It is good to know that sometimes when the balance of substances is disturbed in body tissues or fluids, or their function will be disturbed, the conditions may change so these beneficial microbes become pathogenic. But these situations rarely occur. Alginate has been employed to encapsulate several species of probiotic microbes. Alginate can be incorporated into the diet as a food favored by beneficial gut bacteria (i.e., prebiotics). This helps increase the number of good gut bacteria and promote digestive system health. Alginate capsules, including minerals, vitamins, antioxidants, enzymes, amino acids, etc., are operated as valuable substances for the health of the body in the pharmaceutical industry. Encapsulation of probiotics and prebiotics with alginate compounds enhances shelf life and increases stability and storage, furthermore; the alginate capsule permits the compounds to be mixed with other food products and used without the risk of losing their valuable properties. Alginate can inhibit peroxidation and radical chain reactions. So, it can be utilized as an antioxidant in all types of lipid foods [22, 23].

Diabetes or blood sugar disease is a complication that occurs when glucose (blood sugar) is too high in the body. Owing to the high preponderance of diabetes in these years, numerous people themselves or those around them are involved in this chronic disease. They are looking for a solution to recover as quickly as possible. Patients with diabetes require to obtain specific doses of insulin to regulate blood sugar and prevent dangerous consequences of glucose fluctuations. Insulin analogs are the first and most essential drugs used today to handle blood sugar in diabetic patients and are usually used by injection. This therapeutic method has been a standard procedure for regulating blood sugar fluctuations in people with diabetes for about a century. Maybe one of the most attractive ways to treat people with diabetes is using insulin capsules with alginate. This report is specifically happy for people who find it difficult to inject drugs. The causality for these failures is the ineptitude of insulin to cross the stomach acid barrier. When insulin enters the stomach as tablets or capsules, stomach acid rapidly breaks down all the insulin and destroys its hormonal properties. But because of the resistance and compatibility of alginate with stomach acid, insulin can be quickly delivered to the digestive system [24, 25].

Dietary fibers or oral fibers are structural polysaccharides that are very resistant to small intestinal enzymes and are entirely or partially fermented in the large intestine. For this reason, they are considered a strong regulator of the human digestive system. As a type of fiber, sodium alginate can absorb water molecules, and by this work, it becomes gelatinous and sticky, which makes food digestion slower. So, the food remains in the stomach longer, and you get hungry later. As a result, it is very beneficial for weight loss. In addition, alginate inhibits some enzymes in the digestive system. This action decreases the absorption of some compounds, including cholesterol and glucose, and results in participation in weight control and loss [26, 27]. The use of alginate gel compositions for cell culture in biomedical studies has increased. These gels can be easily used for cell cultures of mammalian cells. Likewise, the effect of sodium alginate microstructures on the growth of some bacteria like *Listeria monocytogenes* has been shown [28, 29].
