Ionic Hydrogel Based on Chitosan Cross-Linked with 6-Phosphogluconic Trisodium Salt as a Drug Delivery System

Abstract

In this work, 6-phosphogluconic trisodium salt (6-PG–Na+) is introduced as a new aqueous and nontoxic cross-linking agent to obtain ionic hydrogels. Here, it is shown the formation of hydrogels based on chitosan cross-linked with 6-PG–Na+. This formulation is obtained by ionic interaction of cationic groups of polymer with anionic groups of the cross-linker. These hydrogels are nontoxic, do not cause dermal irritation, are easy to extend, and have an adequate adhesion force to be applied as polymeric film over the skin. This formulation exhibits a first order release kinetic and can be applied as drug vehicle for topical administration or as wound dressing for wound healing. The primary goal of this communication is to report the identification and utility of 6-phosphogluconic trisodium salt (6-PG–Na+) as a nontoxic cross-linker applicable for cationic polymers.

Concepts for Developing Physical Gels of Chitosan and of Chitosan Derivatives

“…A rapid ionic gelation of chitosan using a 6-phosphogluconic trisodium salt (6-PG-Na + ) was recently reported [46]. The formation of a macroscopic gel was demonstrated by rheometry.…”

Chitosan-Based Nanomaterials for Drug Delivery

“…The remaining drug in the hydrophobic polylactic acid nucleus was slowly released, and this release process was in line with the healing mechanism of the human body. In addition, 6-phosphogluconic trisodium salt [ 38 ], poly-c-glutamic acid [ 111 ] and poly(acrylic acid) (PAA) [ 67 ] can play the similar function to the molecule ionically crosslinked with chitosan as an anionic polymer through polyelectrolyte interaction.…”

“…Free amino and hydroxyl groups have been utilized to generate a wide range of CS derivatives with improved solubility based on its high affinity with functional proteins and the capability to self-assemble [ 36 , 37 ]. Thus, CS has been widely employed in various biomedical and pharmaceutical processes, such as drug/gene/vaccine delivery, tissue engineering, wound healing, and manufacture of cosmetic products [ 38 , 39 , 40 ]. Over the past decade, novel nanomaterials successfully developed from CS have been increasingly reported ( Figure 1 ), with potential applications to targeted drug delivery based on the following features: (1) biocompatibility and ability to serve as reaction sites with other bioactive compounds, (2) protecting unstable drug molecules from strong gastric acids and blood flow responses, (3) ability to adhere to mucosal tissues to improve the absorption of specific drugs, (4) ease in combining with anionic biomacromolecules such as DNA by electrostatic action, and (5) colon-targeted administration [ 11 , 41 , 42 ].…”

Ionotropic Gelation of Chitosan Flat Structures and Potential Applications

“…Three-dimensional structures of chitosan have been recently obtained by ionic gelation of chitosan with 6-phosphogluconictrisodium salt (6-PG-Na + ) [198]. This set of gels are interesting from a biological point of view, since they were found to be no toxic and dermal bio-compatible, showing potential application in topical administration and wound dressing.…”