Healing Wounds Efficiently with Biomimetic Soft Matter: Injectable Self-Healing Neutral Glycol Chitosan/Dibenzaldehyde-Terminated Poly(ethylene glycol) Hydrogel with Inherent Antibacterial Properties.

The high prevalence of acquiring skin wounds, along with the emergence of antibiotic-resistant strains that lead to infections, impose a threat to the physical, mental, and socioeconomic health of society. Among the wide array of wound dressings developed, hydrogels are regarded as a biomimetic soft matter of choice owing to their ability to provide a moist environment ideal for healing. Herein, neutral glycol chitosan (GC) was cross-linked via imine bonds with varying concentrations of dibenzaldehyde-terminated polyethylene glycol (DP) to give glycol chitosan/dibenzaldehyde-terminated polyethylene glycol hydrogels (GC/DP). These dynamic Schiff base linkages (absorption peak at 1638 cm-1) within the hydrogel structure endowed their ability to recover from damage as characterized by high-low strain exposure in continuous step strain rheology. Along with their good injectability and biodegradability, the hydrogels exhibited remarkable inhibition against E. coli, P. aeruginosa, and S. aureus. GC/DP hydrogels demonstrated high LC50 values in vivo using zebrafish embryos as a model system due to their relative biocompatibility and a remarkable 93.4 ± 0.88% wound contraction at 30-dpw against 49.1 ± 3.40% of the control. To the best of our knowledge, this is the first study that developed injectable glycol chitosan/dibenzaldehyde-terminated polyethylene glycol self-healing hydrogels for application in wound healing with intrinsic bacteriostatic properties against the three bacteria.

Pantoea dispersa rhinosinusitis: clinical aspects of a rare sinonasal pathogen.

PURPOSE: There is no report in the literature targeting the role of Pantoea dispersa in rhinosinusitis and P. dispersa has not been identified as a commensal bacterium in the sinonasal cavity. We aimed to investigate the role of P. dispersa in rhinosinusitis. METHODS: We retrospectively reviewed the data of patients diagnosed with rhinosinusitis at a medical center in Taiwan. RESULTS: A total of 274 rhinosinusitis patients underwent sinus culture between July 2017 and July 2019. All 23 patients with acute P. dispersa rhinosinusitis experienced purulent rhinorrhea; three (13%) had nasal obstruction, but none had olfactory dysfunction, facial pressure/pain and nasal polyp. The patients with P. dispersa received a significantly shorter duration of antibiotic treatment (19.9 ± 2.6 vs. 28.9 ± 2.5 days, P = 0.015) and had lower surgery rate (0% vs. 16.7%, P = 0.043) than other patients. Patients with olfactory dysfunction were more likely to receive surgical treatment (P = 0.018). CONCLUSION: Acute rhinosinusitis caused by P. dispersa resulted in less surgical interventions and shorter treatment durations. Olfactory dysfunction may imply longer course and possibility for surgical intervention in chronic rhinosinusitis. The present study revealed that P. dispersa had the potential to colonize in human sinonasal cavities and cause rhinosinusitis.