Regioselective succinylation and gelation behavior of glycol chitosan

Abstract

Chitosan is normally acylated and subsequently conjugated with drugs for biomedical applications. This study examined the relationship between the succinylation and gelation behaviors of glycol chitosan. Glycol chitosan was acylated with succinic anhydride under a wide variety of reaction conditions, such as different molar ratios of succinic anhydride to glucosamine, different methanol content in the reaction media, and different reaction temperatures. Among these reaction parameters, the methanol content in the solvent played an important role in determining the regioseletive succinylating site. N-succinylation and N-N cross-linking occurred regardless of the reaction conditions. However, O-succinylation was observed under specific conditions, i.e. a methanol content > 0.6 (v/v) and a reaction temperature > 25 o C. O-succinylation accelerated the N-O cross-linking of glycol chitosan, and led to gelation. The N-succinylated glycol chitosans were water-soluble, whereas the N-and O-succinylated glycol chitosans formed a gel. These physico-chemical structural differences in the succinylated glycol chitosans would definitely influence subsequent drug-conjugation reactions and consequently the drug loading and release kinetics.

Surface modification of montmorillonite (MMT) using column chromatography technique and its application in silicone rubber nanocomposites

“…[1][2][3][4][5][6][7][8][9][10][11] This is mainly attributed to the nanoscale dimension of silicate layers dispersed in the polymer matrix, which causes a strong interfacial interaction between silicate layers and polymer chains leading to a drastic effect on thermal stability, mechanical, physical, barrier and optical properties with impressive fire resistance properties as compared to pristine polymers. [12][13][14][15][16][17][18] Clay minerals have been extensively used as a reinforcing agent because of their low cost and easy availability 14,19,20 compared to other layered materials.…”

Succinylated polysaccharide-based thermosensitive polyelectrostatic complex for protein drug delivery

“…The 1 H-NMR study shown in Figure 1(b) revealed that the peaks of –CH 2 CH 2 in succinyl groups appeared at 2.4–2.7 ppm. 24 The hydroxyl groups of pullulan were observed at 3.2–5.4 ppm. After polymerization of PLL to SP, new peaks relevant to PLL appeared at 1.5, 4.4, and 5.3 ppm.…”

Enhancement of thermal stability and phase relaxation behavior of chitosan dissolved in aqueous l-lactic acid: Using ‘silver nanoparticles’ as nano filler

“…1 Chitosan is basic in nature and has applications in wound healing, tissue repair, antimicrobial resistance, cell adhesion, food packaging, metal-ion adsorption, drug delivery 2-6 and novel gene delivery. 7,8 In particular, chitosan films are used to extend the shelf life of fruits and vegetables 9 after being coated. Chitosan has already been investigated in the regeneration of skin, cartilage, nerve and liver.…”