Speaker
Description
"Introduction
Using nanofibrous materials for wound healing is very promising yet still challenging. The dressing is usually a composite made of several layers, with a specific role to ensure proper moisture of the wound, breathability, low adhesiveness to the wound and prevention of the infection. One of the benefits that nanofibers have is the ability to easily incorporate antimicrobial drugs. In this work, we focused on the preparation of the wound dressing with two biologically active substances – hyaluronic acid, which plays an important role in wound healing processes, and a hyaluronic acid derivative with an antimicrobial effect. These biologically active ingredients are incorporated in the dressing in the form of a nanofibrous layer, which readily dissolves after contact with wound fluids.
Methodology
The presented wound dressing consisted of a nanofibrous layer based on antimicrobial hyaluronan chloramide (HA-Cl)1 and low molecular weight hyaluronic acid (LMW-HA). Nanofibers were prepared by electrospinning and laminated to a wound contact layer and an absorbent layer. The complete wound dressing was sterilized with ethylene oxide (EtOX). The morphology of nanofibers was studied by SEM. Residual solvents and residues after EtOX sterilization were determined by GC-MS. The amount of LMW HA was determined by HPLC and the amount of HA-Cl by iodometric titration. Permeation of moisture through the wound dressing was measured via a water vapor transmission test and the results were compared with a commercial product. The wound dressing was analyzed for the presence of bacterial endotoxins by the monocyte activation test (MAT). In vitro testing was used for the evaluation of the safety of the wound dressing. The effect of the wound dressing extracts on the viability of 3T3 fibroblasts and migration of HaCaT keratinocytes was assessed as well as the potential for skin irritation where the model of the human epidermis was used. The potential for skin sensitization of wound dressing extract was
assessed by the dendritic cell activation test. The safety of the nanofiber layer was evaluated in vivo using a mouse model of an excisional acute wound.
Results
The large-format electrospun nanofibrous layers were laminated to the wound contact layer and the absorbent layer. The lamination did not affect the nanofibrous structure. The nanofiber structure and the content of the active ingredients did not change after sterilization and no EtOX residues and residual solvent were found. The uniform distribution of LMW HA and HA-Cl in nanofibrous mats was confirmed by HPLC and titration. The permeability of water vapor through the nanofiber wound dressing was similar to a commercial product. The safety of the wound dressing was evaluated by in vitro tests without any negative results. Furthermore, the tested nanofiber layer was well-tolerated when applied to acute mouse excisional wounds.
Conclusion
A new wound dressing with the active nanofibrous layer and homogenous content of bioactive components was produced using the semi-production electrospinning device. The results obtained so far have demonstrated the safety of the bioactive layer and promising results for future development.
References:
1. Buffa, R. et al., Carbohydr Polym 250:116928"
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