RESUMEN
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.
Asunto(s)
Escherichia coli , Staphylococcus aureus , Animales , Biomimética , Pez Cebra , Cicatrización de Heridas , Materiales Biocompatibles/farmacología , Polietilenglicoles/química , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Antibacterianos/química , Hidrogeles/químicaRESUMEN
OBJECTIVE: To determine the required sample size for, and feasibility of, a RCT examining the effectiveness of early acupuncture for acute ischaemic stroke. METHODS: Thirty-eight patients aged 40-85â years with a first episode of acute ischaemic stroke presenting within 72â h of stroke onset were randomly assigned to receive manual acupuncture (MA group; n=20) plus standard care or standard care only (control group, n=18). The acupuncture treatment was provided daily for 2â weeks. The primary outcome was the change in the National Institutes of Health Stroke Scale (NIHSS) score between baseline and 4â weeks. Secondary outcomes included changes in the Fugl-Meyer assessment (FMA) and the functional independence measure scores between baseline and 4â weeks, and changes in NIHSS, Barthel Index and modified Rankin Scale scores at 12â weeks. RESULTS: Thirty-one patients completed the study (dropout rate=18%) and adverse effects were minimal. No significant differences were seen between groups in the improvements in NIHSS scores, although there tended to be a greater reduction in NIHSS score after 1â week in the MA group relative to the control group (p=0.066). The post-stroke motor activity at 4â weeks was associated with a significantly increased FMA score in the acupuncture group compared with the control group (p<0.05), but not supported by intergroup analysis. CONCLUSIONS: This pilot study indicates that acupuncture appears to be safe for patients in the acute stage of ischaemic stroke. A subsequent trial with a larger sample size (estimated at n=122) is required to confirm whether early acupuncture intervention contributes to earlier functional improvement and to assess the longer-term clinical efficacy of acupuncture. TRIAL REGISTRATION NUMBER: NCT02210988; Results.