Preparation and characterization of OSA/CS core–shell microgel: in vitro drug release and degradation properties

Abstract

Cationic polymers have been widely used as drug delivery systems. Herein, an oxidized sodium alginate/chitosan (OSA/CS) core-shell microgel was prepared via water-in-oil emulsion method. Morphological properties of the resulting microgel were determined by transmission electron microscopy, hydrodynamic diameter of the microgel was characterized by dynamic light scattering. The objective of this work was to achieve the colon-specific delivery of an antiulcerative colitis drug using a fully nontoxic carrier. 5-aminosalicylic acid (5-ASA) was chosen as a model drug, which is rapidly absorbed before entering the colon, thus it is necessary to develop a colon-specific delivery system for it. The in vitro drug release profile was established in buffer solutions with 0.1 M HCl/NaCl (pH 1.2) and 0.1 M phosphate buffered saline (pH 7.4) at 37 °C. The results indicated that this OSA/CS core-shell microgel inhibited the release of 5-ASA in stomach to a certain extent and is degradable in physiological conditions. Due to the excellent biocompatible nature of CS and OSA, this core-shell microgel has good biocompatibility and may have potential applications in oral controlled drug delivery systems.

Recent Advances of Chitosan-Based Hydrogels for Skin-Wound Dressings

“…Among the CMCS hydrogel, carboxymethyl chitosan and curcumin play a key role in accelerating burn healing. Carboxymethyl chitosan, a special derivative of chitosan, is synthesized by replacing one or both of the amino (NH 2 ) and hydroxyl (OH) groups in the glucosamine unit with a carboxymethyl (-CH 2 COOH) substituent [ 139 ], possessing high viscosity, low toxicity, and good biocompatibility [ 59 ]. However, these properties are not sufficient for use on burn wounds, as some anti-inflammatory and antioxidant drugs can achieve a better therapeutic effect.…”

Electrostatic Interaction-Based Fabrication of Calcium Alginate–Zein Core–Shell Microcapsules of Regulable Shapes and Sizes

“…16 Chen et al fabricated an oxidized sodium alginate/chitosan core−shell microgel by emulsification. 17 Yang et al combined electrostatic droplets and microfluidic droplets to obtain a core−shell structure having dual pHresponsive drug release function. 18 However, the above-mentioned methods have certain limitations, such as complex preparation procedures, high production cost, and low biocompatibility.…”

“…Sun et al synthesized pullulan–gelatin core–shell nanofibers with improved drug-loading capacity using the electrospinning technology . Chen et al fabricated an oxidized sodium alginate/chitosan core–shell microgel by emulsification . Yang et al combined electrostatic droplets and microfluidic droplets to obtain a core–shell structure having dual pH-responsive drug release function …”

Drug release behavior of poly (lactic-glycolic acid) grafting from sodium alginate (ALG-g-PLGA) prepared by direct polycondensation

“…Alginate, which is one of natural biopolymers, has increasing biotechnological and biomedical applications because of its several advantages, such as that it is a cheap and rich source, its biodegradability, non-toxicity, and non-immunogenicity [1][2][3][4][5]. Sodium alginate (ALG) consists of two kinds of hexuronic acid residues, including 1,4-bDmannuronic acid (M) and a-L-guluronic acid(G) residues, which are arranged in repeating GG, MM blocks or alternating MG blocks.…”