Alginates and similar exopolysaccharides in biomedical application and pharmacy: Controled delivery of drugs

Abstract

Due to its biocompatibility, biodegradability, hydrophility, technological properties and vast availability, polysaccharides are widely used as natural non-toxic polymers in different branches of industry (food, cosmetic, textile, construction industries). Exopolysaccharides (as dextran, pullulan) have recently taken up a significant position in pharmaceutical industry. Alginate has an irreplaceable role in biomedicine, since its hydrogel form is successfully applied for immobilization of a wide range of enzymes, therapeutics, biochemical agents and different kinds of microorganisms and cells (herbal, animal or human). Alginate microspheres and microcapsules are used for controlled release of biologically active molecules, as well as cell carriers in tissue engineering. Special benefits are brought by the simplicity of configuration of alginate hydrogel, including the possibility of the controlled production of micro-and nanoparticles. Taking into account a very important role of alginates in the form of hydrogel in biomedicine, in this paper a specific attention is paid on the preparation and application of alginate matrices, microspheres and microcapsules that may have essential and unexchangeable usage/application. This paper therefore displays various possibilities of use of polysaccharide matrices for biomolecules, polysaccharide as excipients of pharmaceutical products for oral or local application, and provides a review of the examples of innovative applications.

Assessment of Antimicrobic, Antivirotic and Cytotoxic Potential of Alginate Beads Cross-Linked by Bivalent Ions for Vaginal Administration

“…Alginates are widely used in the medicinal and pharmaceutical field. They have a wide range of favorable properties, such as biocompatibility, biodegradability, bioadhesivity [ 7 , 8 ] and structural similarity with the extracellular matrix, making them a biomaterial of choice in the area of wound dressings, tissue engineering and regeneration [ 9 , 10 ]. The formulation of the controlled release dosage forms [ 11 ] and possibility for protein drugs, probiotics, and other live cell encapsulation [ 12 , 13 , 14 ] are other areas of their numerous applications.…”

Analysis of the Degradation Process of Alginate-Based Hydrogels in Artificial Urine for Use as a Bioresorbable Material in the Treatment of Urethral Injuries

“…The guluronic and mannuronic acid residues in the hydrogel structure may arrange in three variants/configurations: two β-d-mannuronic acids residues (MM), two α-l-guluronic acid residues (GG), or alternating connections of the M-and G-blocks (MG). The hydrogels obtained from alginate with a higher number of β-d-mannuronic acid residues have higher elasticity than those made from alginate with a higher number of α-l-guluronic acid residues [13,14,16,17,23]. One of the mechanisms leading to the formation of alginate hydrogels is crosslinking by divalent cations, like Ca 2+ .…”

The Layered Encapsulation of Vitamin B2 and β-Carotene in Multilayer Alginate/Chitosan Gel Microspheres: Improving the Bioaccessibility of Vitamin B2 and β-Carotene

“…The VB is unstable under alkaline conditions, thus the rapid release of VB in the stomach, once it moves to the alkaline conditions of colon, which can quickly be absorbed. Release was divided into two main methods: drug release via degradation of the alginate network and drug diffusion through the alginate network for the drug release mechanism of the gel microspheres system [ 50 ]. When the gel microspheres were placed at pH 2.0, the COO– groups of SA started to protonate, forming uncharged –COOH groups; thus, the alginate network became loose due to reduction in the degree of crosslinking of SA with Ca 2+ , and the electrostatic repulsion between the SA and CS increased [ 49 ].…”