Polysaccharide-based hydrogels for medical devices, implants and tissue engineering: A review.

Hydrogels are highly biocompatible biomaterials composed of crosslinked three-dimensional networks of hydrophilic polymers. Owing to their natural origin, polysaccharide-based hydrogels (PBHs) possess low toxicity, high biocompatibility and demonstrate in vivo biodegradability, making them great candidates for use in various biomedical devices, implants, and tissue engineering. In addition, many polysaccharides also show additional biological activities such as antimicrobial, anticoagulant, antioxidant, immunomodulatory, hemostatic, and anti-inflammatory, which can provide additional therapeutic benefits. The porous nature of PBHs allows for the immobilization of antibodies, aptamers, enzymes and other molecules on their surface, or within their matrix, potentiating their use in biosensor devices. Specific polysaccharides can be used to produce transparent hydrogels, which have been used widely to fabricate ocular implants. The ability of PBHs to encapsulate drugs and other actives has been utilized for making neural implants and coatings for cardiovascular devices (stents, pacemakers and venous catheters) and urinary catheters. Their high water-absorption capacity has been exploited to make superabsorbent diapers and sanitary napkins. The barrier property and mechanical strength of PBHs has been used to develop gels and films as anti-adhesive formulations for the prevention of post-operative adhesion. Finally, by virtue of their ability to mimic various body tissues, they have been explored as scaffolds and bio-inks for tissue engineering of a wide variety of organs. These applications have been described in detail, in this review.

Polysaccharide-based hydrogels for drug delivery and wound management: a review.

INTRODUCTION: Polysaccharide-based hydrogels (PBHs) offer several advantages over their synthetic counterparts. Their natural origin contributes to their nontoxicity, high biocompatibility, and in vivo biodegradability. Their properties can be tuned finely to obtain hydrogels with desired mechanical, structural, and chemical properties. AREAS COVERED: Such versatile characteristics have potentiated the use of PBHs for the delivery of drugs, vaccines, protein and peptide therapeutics, genes, cells, probiotics, bacteriophages, and other therapeutic agents. Recent advances in hydrogel-based formulations such as nanogels, microgels, microneedles, hydrogel beads, nanocarrier-loaded hydrogels, and complexation hydrogels have enabled the precise delivery of a wide range of therapeutics. This review aims to give a holistic overview of hydrogels in the delivery of a variety of therapeutics through different routes. EXPERT OPINION: PBHs have been used to enable the oral delivery of vaccines and other biologicals, thereby allowing self-administration of life-saving vaccines during public health emergencies. There is a lack of commercialized wound dressings for the treatment of chronic wounds. PBH-based wound dressings, especially those based on chitosan and loaded with actives and growth factors, have the potential to help in the long-term treatment of such wounds. Recent developments in the 3D printing of hydrogels can enable the quick and large-scale production of drug-loaded hydrogels.

Development and evaluation of a suppository formulation containing Lactobacillus and its application in vaginal diseases.

Lactobacillus has long been considered the protective flora in the vagina that displaces and kills vaginal pathogens. Lactic acid, H2O2, and antibacterial agents such as lactocin and bacitracin produced by Lactobacillus act against the vaginal pathogens. The first objective of this research was to develop a local application pharmaceutical formulation of a vaginal suppository containing lyophilized culture of Lactobacillus. The second objective was to establish its in vivo performance by developing in vitro methods of evaluation. Lyophilized culture of Lactobacillus sporogenes was selected for this study. Three formulations of the suppositories were prepared by the molding method. Formulations I, II, and III contained cocoa butter, glycerinated gelatin, and PEG 1000 base, respectively. The prepared suppositories were characterized for physical properties. Assembly to simulate the application site was designed. Methods to evaluate the viability, production of lactic acid, and H2O2 produced by the released Lactobacillus at the application site were developed and the antagonistic activity was demonstrated. From the physical characteristics of the suppository formulations, the glycerinated gelatin suppository (formulation II) containing lyophilized Lactobacillus was found to be satisfactory. The developed assembly was satisfactory in simulating the application site. The Lactobacillus released was viable and exhibited the production of lactic acid, hydrogen peroxide, and antagonistic activity against the uropathogen. The suppository formulation containing Lactobacillus and the methods of its evaluation were successfully developed in this research work and have several applications in the vaginal diseases of women.