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Objective The moisturizing and irritation effects of sacha inchi oil were evaluated. Study Design The moisturizing effect on the skin was clinically assessed using a regression study design. Sacha inchi oil or olive oil (benchmark) was applied on the left or right lower leg of the subjects for 14 days followed by application discontinuation for 2 days. The TEWL, skin moisture content and dryness appearance were observed. Methods The fatty acid composition and characteristics of cold‐pressed sacha inchi seed oil were determined. Skin tissues cultured ex vivo were used to assess primary irritation induced by the oil by examining keratin 1 expression and TNF‐α and IL‐1α release from the oil‐applied tissues. Results The sacha inchi oil contained 42.3% linolenic acid and 39.5% linoleic acid. This oil's saponification, iodine, acid and peroxide values were 168.58 ± 1.55 mg KOH/g, 203.00 ± 0.04 g I2/100 g, 1.68 ± 0.03 mg KOH/g, and 1.95 ± 0.26 mEq peroxide/kg, respectively. Compared with nontreated skin tissues, induced secretion of TNF‐α and IL‐1α and disruption of keratin 1 integrity in the stratum corneum layer were not found in the sacha inchi oil‐treated tissues. In a clinical study with 13 volunteers, the improvement in moisture content and skin dryness appearance at the sacha inchi oil‐applied site was comparable with that observed at the olive oil‐applied site. Conclusions The sacha inchi oil was mild to the skin and benefited dry skin.

The physicochemical and biological properties of the blended fibroin/aloe gel film as a wound dressing were investigated to support the wound healing efficacy of the film described in our previous study. In the current study, protein content, molecular weight pattern, and chemical characteristics of the silk fibroin and the aloe gel extracts were analyzed. The two extracts were then dissolved in lactic acid solution and casted to obtain the blended fibroin/aloe gel film. We found that gamma irradiation did not affect any physicochemical properties of the film, i.e., the irradiated and the non-sterilized films had similar physical appearance, surface morphology, mechanical properties, and chemical characteristics. On normal human fibroblast cultures, the film induced non-cytotoxicity and stimulated the expression of vascular epidermal growth factor. The film-treated cells were shown to proliferate by shifting from G 0 /G 1 phase (76.26 ± 0.72%) to S phase (7.19 ± 0.23%) and G 2 /M phase (16.09 ± 0.58%) which are higher than the untreated cells. The film-treated cells provided a completely healed scratch at 36 h after scratch creation, while the created scratch of the untreated cells was not healed, indicating that the biological activity of the film enhanced the proliferation and the migration of fibroblast cells. We speculated that the prepared film might be able to use as wound dressing for the diabetic foot ulcer.

In diabetic patients, the process of wound healing is usually delayed or impaired. A diabetic environment could be associated with dermal fibroblast dysfunction, reduced angiogenesis, the release of excessive proinflammatory cytokines, and senescence features. Alternative therapeutic treatments using natural products are highly demanded for their high potential of bioactive activity in skin repair. Two natural extracts were combined to develop fibroin/aloe gel wound dressing. Our previous studies revealed that the prepared film enhances the healing rate of diabetic foot ulcers (DFUs). Moreover, we aimed to explore its biological effects and underlying biomolecular mechanisms on normal dermal, diabetic dermal, and diabetic wound fibroblasts. Cell culture experiments showed that the γirradiated blended fibroin/aloe gel extract film promotes skin wound healing by enhancing cell proliferation and migration, vascular epidermal growth factor (VEGF) secretion, and cell senescence prevention. Its action was mainly linked to the activation of the mitogen-activated protein kinases/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway known to regulate various cellular activities, including proliferation. Therefore, the findings of this study confirm and support our previous data. The blended fibroin/aloe gel extract film displays a biological behavior with favorable properties for delayed wound healing and can be considered as a promising therapeutic approach in the treatment of diabetic nonhealing ulcers.

Objective: This study aimed to develop a wound dressing prepared from the blending of silkworm fibroin and aloe gel extract for use in the treatment of diabetic foot ulcers (DFUs). Methods: Fibroin extracted from silkworm cocoons and aloe gel extract were dissolved in deionised water. pH levels were then adjusted with lactic acid solution. A simple casting technique was used to obtain the fibroin–aloe gel film. The surface morphology, hardness, flexibility and infrared spectrum of the sterilised film were tested. Swelling ratio was measured from changes in weight. The cytocompatibility of the film to human dermal fibroblast was determined using XTT assay. Hard-to-heal DFUs (grade I Wagner score) were treated with the film for four weeks. The application site was assessed for allergic reactions and/or sensitisation. Wound size was measured using standardised digital photography. Results: A total of five hard-to-heal DFUs were treated. The obtained film sterilised with ozonation showed a non-porous structure. The elongation at break and tensile strength of the wet film were 9.00±0.95% and 6.89±1.21N, respectively. Fourier-transform infrared spectroscopy data indicated the presence of amides I, II and III, of peptide linkage, which are the chemical characteristics of the fibroin. Functional groups relating to healing activity of the aloe gel extract were also found. The swelling ratio of the film immersed in water for 24 hours was 0.8±0.01. In three DFUs (40–50mm2 in size), a wound area reduction of 0.4–0.8mm2/day was observed and were healed in 2–3 weeks. The remaining two SFUs (500mm2 in size) showed a wound area reduction of 4mm2/day and were almost closed at four weeks. No allergic reaction or infection was observed in any of the wounds. Conclusion: The obtained film showed a non-porous structure, and its strength and flexibility were adequate for storage and handling. The film tended to increase the proliferation of fibroblasts. The wound dressing showed potential for accelerating the healing rate of DFUs.