Sphingan WL gum (WL) is an extracellular polysaccharide with a carboxyl group produced by Sphingomonas sp. WG. Recently, we have successfully obtained deacetylated WL (DWL) with good water solubility by alkaline treatment. In this study, a DWL-based microgel (named DWLM) with semi-interpenetrating network structure was constructed for the first time and used to deliver the oral drug ciprofloxacin hydrochloride (CIP). DLS results suggested that DWLM had a dual response to pH and temperature. The in vitro cumulative drug release curves showed that the amount of CIP released from the microgel was higher at pH 6.8 than that at pH 3.0. Biocompatibility assessments using HEK293T showed that cell viability was 75.9 ± 1.7% at the DWLM-CIP concentration of 4 mg/mL. While, the cell viability of CIP at the same concentration was only 54.9 ± 1.0%, indicating that DWLM-CIP has good biocompatibility. Antimicrobial performance tests revealed that DWLM-CIP at a concentration of 1 mg/mL could effectively inhibit the growth of Escherichia coli for up to 4 days. When the concentration of DWLM-CIP reached 4 mg/mL, the growth of Staphylococcus aureus was effectively suppressed for up to 3 days, demonstrating the long-lasting antimicrobial efficacy of DWLM-CIP. All of these results indicate that DWL-based microgels have great potential as oral drug delivery carriers.
Sphingan WL gum (WL), a kind of exopolysaccharides , is produced by Sphingomonas sp. WG. In this study, citric acid (CA) crosslinked WL hydrogel films were firstly developed for potential wound dressing application. ATR-FTIR and TG results suggested the occurrence of esterification crosslinking. SEM analysis showed that this aided covalent crosslinking could prevent their porous structures from collapsing when swelling. Due to the deprotonation of carboxyl groups, the water absorption capacity of WL-CA hydrogel films increased with the increase of pH (maximum swelling ratio = 38 g/g). The covalent crosslinked swollen WL-CA hydrogels exhibited certain hydrolytic stability, high porosity (>60%), moderate tissue adhesion, and good rheological property (G′ > G″, G′ up to 2 kPa). WL-CA-CIP hydrogel films loaded with antibiotic ciprofloxacin (CIP) showed sustained drug release properties, long-lasting antibacterial activity , and superior biocompatibility. All the results indicated that WL-based hydrogels were potential candidates for wound dressing applications.
危险品化学品经营许可证（带存储）