Despite the high regenerative capacity of bone tissue, there are some cases where bone repair is insufficient for a complete functional and structural recovery after damage. Current surgical techniques utilize natural and synthetic bone grafts for bone healing, as well as collagen sponges loaded with drugs. However, there are certain disadvantages associated with these techniques in clinical usage. To improve the therapeutic efficacy of bone tissue regeneration, a number of drug delivery systems based on biodegradable natural and synthetic polymers were developed and examined in in vitro and in vivo studies. Recent studies have demonstrated that biodegradable polymers play a key role in the development of innovative drug delivery systems and tissue engineered constructs, which improve the treatment and regeneration of damaged bone tissue. In this review, we discuss the most recent advances in the field of polymer-based drug delivery systems for the promotion of bone tissue regeneration and the physical-chemical modifications of polymers for controlled and sustained release of one or more drugs. In addition, special attention is given to recent developments on polymer nano- and microparticle-based drug delivery systems for bone regeneration.

https://www.mdpi.com/2073-4360/12/12/2881/pdf

Progress and Prospects of Polymer-Based Drug Delivery Systems for Bone Tissue Regeneration.

Sodium alginate beads are usually prepared in the presence of Ca 2+ ions. Here we prepared Graphene oxide based Sodium Alginate-Carrageenan (Ala-Car) hydrogel beads using copper metal ions as ionic crosslinker. The hydrogel beads were prepared by injecting bio-polymers into a beaker containing Cu 2+ ions following rapid magnetic bead strategy. The shape and mechanical properties of hydrogel beads were influenced by concentration of copper ions and amount of the biopolymers used. Rheological and textural analysis was carried to investigate the mechanical and deformation studies of the hydrogel beads and the concentration of copper ions was optimized accordingly. Structural and morphological characterization was done by using FTIR and FESEM analysis. The hydrogels showed high removal capacity than the reported hydrogels of sodium alginate for methylene blue (MB) removal. Keeping the dosage of the adsorbent concentration constant (Ala:Car:GO = 2:2:1) and pH 9.2 conditions, percent removal ranged between 70% and 80% at lower concentrations and went upto about 90% at 60 mg/L of the initial dye concentration. As per Langmuir model, maximum adsorption was observed to be 132 mg/g for Ala: Car: GO ratio of 2:2:1. The dye absorption followed langmuir adsorption isotherm. The synthesized hydrogel beads show multi-functionalities (double network of polymers and graphene oxide) as such may potentially be used for removal of harmful dyes from the waste water as well as from aqueous waters. • Prepared multifunctional biopolymer Sodium Alginate- Carrageenan based hydrogel beads crosslinked by Cu 2+ ions. • Investigated the compressibility and stability of beads in presence and absence of graphene oxide by texture analysis. • The hydrogels beads displayed efficient removal capacity towards removal of Methylene blue dye. 

Multicomponent Interpenetrating metal based Alginate-Carrageenan biopolymer Hydrogel beads substantiated by Graphene oxide for efficient removal of Methylene Blue from waste water

Over the last two decades, bio-polymer fibers have attracted attention for their uses in gene therapy, tissue engineering, wound-healing, and controlled drug delivery. The most commonly used bio-polymers are bio-sourced synthetic polymers such as poly (glycolic acid), poly (lactic acid), poly (e-caprolactone), copolymers of polyglycolide and poly (3-hydroxybutyrate), and natural polymers such as chitosan, soy protein, and alginate. Among all of the bio-polymer fibers, alginate is endowed with its ease of sol–gel transformation, remarkable ion exchange properties, and acid stability. Blending alginate fibers with a wide range of other materials has certainly opened many new opportunities for applications. This paper presents an overview on the modification of alginate fibers with nano-particles, adhesive peptides, and natural or synthetic polymers, in order to enhance their properties. The application of alginate fibers in several areas such as cosmetics, sensors, drug delivery, tissue engineering, and water treatment are investigated. The first section is a brief theoretical background regarding the definition, the source, and the structure of alginate. The second part deals with the physico-chemical, structural, and biological properties of alginate bio-polymers. The third part presents the spinning techniques and the effects of the process and solution parameters on the thermo-mechanical and physico-chemical properties of alginate fibers. Then, the fourth part presents the additives used as fillers in order to improve the properties of alginate fibers. Finally, the last section covers the practical applications of alginate composite fibers.

/pdf/alginate-based-bio-composites-and-their-potential-3hohuo3a.pdf

Alginate-Based Bio-Composites and Their Potential Applications

Since last decades, various polysaccharides are being used in many biomedical applications including dentistry. In the field of dentistry, a considerable volume of research has recently been evidenced for dental drug delivery and dental tissue restoration/regeneration with the use of many polysaccharides and their tailored forms. Many tailored polysaccharides-based dental drug delivery formulations have shown great potential in controlling drug release at the diseased site of tooth, whereas several tailored polysaccharides-based dental tissue restoration/regeneration scaffold materials have shown excellent restoration/regeneration of different dental tissues, such as periodontal bone and ligament, cementum, gingiva, etc.

Uses of tailored polysaccharides in dentistry

Emerging novel approaches for bone tissue regeneration and engineering are based on bioactive materials scaffolding architectures for mimicking naturally occurring extracellular matrix while also a...

Recent advancements in hybridized polymer nano-biocomposites for tissue engineering

The biopolymeric hydrogels are being employed as the promising carriers for delivery of numerous kinds of drug candidates. Hydrogel systems are capable of absorbing higher volume of aqueous fluid while keeping intactness of the structural features. These also provide an easy implementation of the targeted and controlled releasing of drugs to the specific organs. Their use can minimize the unfavorable side effects of conventional drug delivery. Alginate is an abundant natural polysaccharide that possesses various freely existing hydroxyl and carboxyl functional groups along with its structural backbone and thus can be modified chemically. Alginate-based hydrogels have been designed by using different strategies which are either based on various kinds of physical and/or chemical cross-linking methodologies. Recent years, the drug delivery research and development have witnessed a tremendous growth for the prospective use of various alginate-based hydrogels. Due to increasing interest and great potential of these alginate-based hydrogels, this chapter is intended to present a comprehensive overview of the existing state-of-the-art technology in producing various alginate-based hydrogels and their evaluations for the use in drug delivery.

Alginate-based hydrogels for drug delivery applications

Alginates are natural biopolymers, which have extensively been employed for the use in drug delivery applications owing to bioadhesivity, biodegradability, non-toxicity and ease of availability. It possesses numerous distinct properties for developing different biomedical composites with other biopolymers for a broad area of biomedical applications like drug delivery, tissue engineering, wound healing, etc. Alginate-based biocomposite systems are the exclusive carriers for the applications in controlled drug delivery owing to their potency to encapsulate and delivery of numerous therapeutic agents. Besides the simpler processing techniques, mechanical strength, good bioavailability, controlled release rates, stability, targeted delivery of various agents and large-scale manufacturing with cost-effectiveness are the advantages of these alginate-based biocomposites. The current chapter presents a comprehensive review on various alginate-based biocomposites (both alginate-other biopolymeric and alginate-bioinorganic biocomposites) and their applications in drug delivery. In addition, a brief introduction about composites and biocomposites along with sources, chemistry and various important properties of alginates are discussed.

Biocomposites of Alginates in Drug Delivery

Chitosan: source, chemistry, and properties

Polysaccharides derived from natural resources such as plants, seaweeds, fungus, microbes, animals, etc., possess some exclusive characteristics such as aqueous solubility, stability, excellent swelling ability, biodegradability, biocompatibility, etc. These polysaccharides are also being used in various biomedical uses, such as delivery of drugs, growth factors, gene materials, protein encapsulation, wound healing, tissue regeneration, bioimaging, etc. In this chapter, the different biomedical uses of polysaccharides have been reviewed.

Biomedical applications of polysaccharides

Hydroxyapatite (HAp) is one of the extensively explored bioceramic materials in numerous biomedical applications Nowadays, chemically synthesized HAp has been manufactured by different chemical synthetic routes to formulate HAp-based systems for orthopedic uses like drug delivery, tissue regeneration, and orthopedic prosthesis Recent years, several HAp-based composites are being developed for various orthopedic uses like drug-release and tissue engineering The current chapter presents an inclusive overview on different HAp-based composites for orthopedic drug-release and tissue engineering applications

Mala Maity

Papers

Alginate-based hydrogels for drug delivery applications

Biocomposites of Alginates in Drug Delivery

Chitosan: source, chemistry, and properties

Biomedical applications of polysaccharides

Hydroxyapatite-based composites for orthopedic drug delivery and tissue engineering