(T1130-12-68) Thermosensitive Lactobacillus brevis-Loaded Composite Double-Layered Dressing with Improved Mechanical Properties and Excellent Wound Recovery

Purpose: The objective of this study was to develop a novel composite double-layered dressing (CDD), with improved mechanical properties and wound recovery, to administer the thermosensitive drug Lactobacillus brevis (LB).

Methods: The system was based on the release of LB to enhance the activation of tissue regeneration in infected wounds. The CDD was composed of an LB-loaded hydrogel top layer with an external hydrocolloid type layer. The high-temperature melting method was employed to produce the external layer of the dressing (Fig. 1A), using polyisobutylene (PIB), styrene-isoprene-styrene copolymer (SIS copolymer), paraffin oil, and sodium carboxymethylcellulose (CMC). The LB-loaded hydrogel top layer was prepared by the freeze-thawing method using polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) (Fig. 1B & C)

Results: Numerous LB-loaded CDDs were prepared at various ingredient ratios; their swelling and mechanical properties and LB release were assessed. A novel LB-loaded CDD, composed of a PVP/PVA (0.5/10) hydrogel top layer and a PIB/SIS copolymer/paraffin oil/ CMC (20/25/12/43) external hydrocolloid membrane, revealed excellent mechanical properties (about 5.20×10^-3 N/mm², Young’s modulus), swelling capacity (about 800 %), and drug release (about 67% at 120 min) (Fig. 2). Moreover, the in vivo wound recovery potential of the selected LB-loaded CDD was evaluated in P. aeruginosa infected wound models and compared with those of a commercial product and a CDD without LB (Fig. 3).

Conclusion: The developed novel LB-loaded CDDs were considered an effective treatment for infected wounds and a potential thermosensitive drug carrier, which could improve the efficacy of wound recovery.

Fig. 1. Scanning electron micrographs; (A), hydrocolloid membranes; (B), the hydrogel surface of CDD without LB; (C), the hydrogel surface of LB-loaded CDD



Fig. 2. Comparison of PVP/PVA ratios (0.5/10 vs. 1/10 ratio) of LB-loaded CDDs: (A) drug release profile and (B) log percent drug released as a function of log time. Each value represents the mean±SD (n = 6).



Fig. 3. Representative images (A) and wound recovery profile (B) in a wound infected with Pseudomonas aeruginosa: (a), non-treated; (b), commercial product; (c), CDD without LB; (d), LB-loaded CDD. + P<0.05 compared with non-treated, * P<0.05 compared with non-treated and commercial product, # P<0.05 compared with non-treated, commercial product, and CDD without LB