Synergistic Effects of Quercetin-Modified Silicone Gel Sheet in Scar Treatment.

Both silicone gel and quercetin are effective in scar treatment but have different action mechanisms. Quercetin is mainly applied in the gel form and can lead to poor adhesion of silicone gel sheet; therefore, they cannot be combined in clinical use. In this study, a silicone gel sheet that releases quercetin in a sustained manner for 48 hours was successfully developed. Four round scars (Ø: 1 cm) were made in the ears of New Zealand albino rabbits (n = 10). After scar healing, the rabbits were divided into four groups: blank control group with no treatment, silicone gel sheet group with dressing change every 2 days, quercetin group with dressing change three times daily, and combination treatment group with dressing change every 2 days. Scar assessment was performed 3 months later. Transepidermal water loss showed no difference between the combination treatment group and the silicone gel sheet group, but was lower than that in the quercetin group and the blank control group. Immunohistochemistry of CD 31 and proliferating cell nuclear antigen showed the following results: combination treatment group < silicone gel sheet group = quercetin group < blank control group. Polymerase chain reaction results showed that the expression of type-I and type-III collagen in the combination treatment group and the quercetin group was significantly lower than that in the other two groups. Thus, quercetin-modified silicone gel sheet combines the advantages of the two treatments and is more effective at inhibiting cell proliferation in scar tissue than either of the two treatments alone.

[Influence of polyester gauze on evaporation capacity and healing of the surface of microskin graft wound after escharectomy].

OBJECTIVE: To investigate the influence of polyester gauze on evaporation capacity and its clinical effect after escharectomy of deep burn wound and micro-skin grafting. METHODS: Twenty patients with deep burn admitted within 24 hours after injury underwent escharectomy and Meek skin grafting. Two surfaces of wound with the area of about 1% as the whole wound surface were used, one covered by Meek skin graft and polyester gauze as inner dressing (polyester gauze group), and the other covered by split-thickness skin sheet 0.3 mm x 0.3 mm in size and vaseline oil gauze as inner dressing (vaseline oil gauze group). Five days after skin grafting, the evaporation capacities of the surface of inner dressing, wound surface without dressing (nude wound), and normal skin near the wound were tested by evaporation test equipment. The complete healing time and survival rate of skin sheet in both groups were observed. The degree of pain during dressing change was evaluated with visual analog scale. RESULTS: The evaporation capacity of the inner dressing surface of polyester gauze group was (24.8 +/- 5.2) ml x h(-1) x m(-2), significantly lower than those of the vaseline oil gauze group [(35.4 +/- 5.0) ml x h(-1) x m(-2), P < 0.01] and nude wound [(41.3 +/- 4.5) ml x h(-1) x m(-2), P < 0.01], and similar to that of the normal skin near the wound [(21.1 +/- 5.1) ml x h(-1) x m(-2), P > 0.05]. The evaporation capacity of the inner dressing surface of vaseline oil gauze group was significantly lower than nude wound [(40.7 +/- 3.6) ml x h(-1) x m(-2), P < 0.01], but significantly higher than the normal skin near the wound [(21.2 +/- 3.8) ml x h(-1) x m(-2), P < 0.01]. The survival rate of skin sheets of the polyester gauze group was 98% +/- 3%, not significantly different from that of the vaseline oil gauze group (98% +/- 2% , P > 0.05). The wound healing rates on days 10, 15, and 20 of the polyester gauze group were 80% +/- 20%, 96% +/- 7%, and 100% respectively, all significantly higher than those of the vaseline oil gauze group (70% +/- 33%, 81% +/- 21%, and 97% +/- 11% respectively, all P < 0.01). The complete healing time of the polyester gauze group was (13.6 +/- 1.9) days, significantly shorter than that of the vaseline oil gauze group [(16.7 +/- 2.6) days, P < 0.01]. The pain scores during dressing change 5 and 10 days after grafting of the polyester gauze group were (3.2 +/- 0.8) and (4.9 +/- 0.4) respectively, both significantly lower than those of the vaseline oil gauze group [(5.1 +/- 0.6) and (8.2 +/- 0.5) respectively, both P < 0.01]. CONCLUSIONS: Polyester gauze has quite good abilities to retain moisture and can promote the migration and proliferation of epithelial cells, relieves the pain caused by tearing of dressings off the wound, thus raising its acceptability. It is a relatively ideal carrier of skin grafting, as well as a new type of inner cover for the wound.

A new method of wound treatment: targeted therapy of skin wounds with reactive oxygen species-responsive nanoparticles containing SDF-1α.

OBJECTIVE: To accelerate wound healing through promoting vascularization by using reactive oxygen species (ROS)-responsive nanoparticles loaded with stromal cell-derived factor-1α(SDF-1α). METHODS: The ROS-reactive nanomaterial poly-(1,4-phenyleneacetone dimethylene thioketal) was synthesized, and its physical and chemical properties were characterized. ROS-responsive nanoparticles containing SDF-1α were prepared through a multiple emulsion solvent evaporation method. The loading capacity, stability, activity of the encapsulated protein, toxicity, and in vivo distribution of these nanoparticles were determined. These nanoparticles were administered by intravenous infusion to mice with full-thickness skin defects to study their effects on the directed chemotaxis of bone marrow mesenchymal stem cells, wound vascularization, and wound healing. RESULTS: The synthesized ROS-reactive organic polymer poly-(1,4-phenyleneacetone dimethylene thioketal) possessed a molecular weight of approximately 11.5 kDa with a dispersity of 1.97. ROS-responsive nanoparticles containing SDF-1α were prepared with an average diameter of 110 nm and a drug loading capacity of 1.8%. The encapsulation process showed minimal effects on the activity of SDF-1α, and it could be effectively released from the nanoparticles in the presence of ROS. Encapsulated SDF-1α could exist for a long time in blood. In mice with full-thickness skin defects, SDF-1α was effectively released and targeted to the wounds, thus promoting the chemotaxis of bone marrow mesenchymal stem cells toward the wound and its periphery, inducing wound vascularization, and accelerating wound healing.