Development of Lactobacillus brevis-loaded double-layered wound dressing

Abstract

The conservative single-layered hydrocolloid dressing has excellent dressing properties but cannot load thermosensitive materials. The goal of this study was to develop Lactobacillus brevis (L. brevis)-loaded double-layered wound dressing (LDW) with great dressing properties such as tensile strength, elongation at break, Young’s modulus, swelling ratio and release, and an enhanced healing effect compared to the conservative hydrocolloid dressing system. The LDW was prepared with hydrocolloid single layer and L. brevis-loaded hydrogel single layer. The hydrocolloid was composed of polyisobutylene (PIB), styrene-isoprene-styrene copolymer (SIS), liquid paraffin and sodium alginate at the weight ratio of 20/25/12/43 prepared by hot melting process. The hydrogel part of LDW was prepared with L. brevis (1.83 × 1010 CFU/gel), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), glycerol and phosphate-buffered saline (PBS) using three cycles of freezing-thawing technique. The dressing properties of LDW were evaluated compared to single-layered hydrocolloid and the ability of LDW to release L. brevis was evaluated. In vivo wound healing effects and histopathological profiles were also assessed compared to commercial products. The LDW showed great mechanical properties (tensile strength, 1.654 N/mm2; elongation at break, 334.7%; Young’s modulus, 0.493 N/mm2), swelling capacity (swelling ratio, 837.0%) comparable to single-layered hydrocolloid and exhibited great release property (65.73%). Moreover, it significantly enhanced the wound healing effect in the excision wound model (wound healing, 95.83%) and infection wound model (S. aureus model wound healing, 96.40%; P. aeruginosa model wound healing, 96.36%) compared to the commercial product (excision model, 89.79%; S. aureus model, 86.69%; P.aeruginosa model, 87.34%). Therefore, the LDW would be a remarkable dressing system with good dressing properties and enhanced wound healing.