Evaluation of collagen type I scaffolds including gelatin-collagen microparticles and Aloe vera in a model of full-thickness skin wound.

Research on collagen type I scaffolds with Aloe vera is sparse. The aim of this work was to develop collagen type I scaffolds with gelatin-collagen microparticles and loaded with a dispersion of A. vera, to assess their performance as grafting material for healing of skin wounds. Scaffolds were evaluated in a Cavia porcellus model with full-thickness skin wound and compared with wounds healed by secondary intention (controls). Animals grafted with scaffolds without A. vera and their control wounds were also included in the study. Evaluation of enzymatic degradation and percentage of the scaffolds' free amino groups-as an indirect assessment of their cross-linking-were also carried out because A. vera contains compounds which affect their stability. We found that dispersions of lyophilized A. vera extract loaded on scaffolds do not have cytotoxic potential, and they decrease collagenase degradation of scaffolds in the range of 0.1 to 0.3% w/v in a dose-dependent manner. Only the A. vera dispersion with the highest concentration (0.3% w/v) decreased the percentage of free amino groups, which are the ones involved in the cross-link of collagen fibers. This finding suggests that cross-linking is not the mechanism by which the tested dispersions stabilize the scaffolds. Preclinical, histochemical, and histomorphometric analyses of repaired wound tissue indicate that loading collagen type I scaffolds, including microparticles of gelatin-collagen, with A. vera in the concentrations tested does not improve wound healing. Low biodegradability of the tested scaffolds caused by the inhibition of collagenase activity might account for these results.

Effect of acupuncture on allergen-induced basophil activation in patients with atopic eczema:a pilot trial.

OBJECTIVE AND METHODS: The crucial symptom of atopic eczema is itch. Acupuncture has been shown to exhibit a significant effect on experimental itch; however, studies focusing on clinical itch in atopic eczema and corresponding mechanisms are lacking. The study design was a unicenter, single-blinded (observer), prospective, randomized clinical pilot trial with an additional experimental part. In 10 patients with atopic eczema, we investigated the effect of acupuncture treatment (n = 5) compared to no treatment (n = 5) on itch intensity and in vitro basophil CD63 expression upon allergen stimulation (house dust mite and timothy grass pollen) in a pilot trial. RESULTS: Mean itch intensity in a visual analog scale was rated significantly lower in the acupuncture group (-25% ± 26% [day 15-day 0]; -24% ± 31% [day 33-day 0]) than in the control group (15% ± 6% [day 15-day 0]; 29% ± 9% [day 33-day 0]). From day 0 (before treatment) to day 15 (after 5 acupuncture treatments) as well as day 33 (after 10 acupuncture treatments), the acupuncture group showed less CD63 positive basophils than the control group regarding stimulation with house dust mite and grass pollen allergen at various concentrations (5 ng/mL, 1 ng/mL, 0.5 ng/mL, or 0.25 ng/mL). CONCLUSIONS: Our results show a reduction of itch intensity and of in vitro allergen-induced basophil activation in patients with atopic eczema after acupuncture treatment. Reducing basophil activation can be a further tool in investigating the mechanisms of action of acupuncture in immunoglobulin E-mediated allergy. Due to the limited number of patients included in our pilot trial, further studies are needed to strengthen the hypothesis.