Physicochemical and biological activities of the gamma-irradiated blended fibroin/aloe gel film

Abstract

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.

Beneficial Effects of a Blended Fibroin/Aloe Gel Extract Film on the Biomolecular Mechanism(s) via the MAPK/ERK Pathway Relating to Diabetic Wound Healing

“…These results implied that the film extract behaved as having a noncytotoxicity effect on fibroblast cells and might also have the potential to stimulate cell viability and proliferation. Also, the results were similar to our previous study …”

“…As the depicted cell cycle data implies, the film-treated cells shifted from the G0/G1 phase to the S phase by binding to cyclin D/CDK4,6 complexes that regulate G1-S phase transit. The film extract promoted cells to enter the S phase via the pathway of acemannan, which is an important stage for mitosis and cell growth by influencing cyclin-dependent cell cycle progress through translational regulation of cyclin D1 . Our cell cycle finding was liable to Yuan et al who reported that after treating with aloe polysaccharide, the number of cells was increased in the S and G2/M phases preparing for mitosis, and cyclin D1 protein was upregulated in a concentration-dependent manner .…”

“…Fibroin from silk cocoon (Bombyx Mori, Nang-Laai strain) and aloe gel extract from the gel part of the aloe vera (Aloe barbadensis miller) leaf were extracted separately to achieve the lyophilized form. Subsequently, they were qualified to control the physicochemical characteristics prior to the preparation of the film according to our previous study. ,, The obtained fibroin commonly provided a percentage of yield in the range of 54–58% w/w and protein content in the range of 97.43 ± 0.44% w/w. For the infrared spectra obtained using Fourier transform infrared (FTIR) spectroscopy, amide I at 1611–1696, amide II at 1501–1550, and amide III at 1200–1320 cm –1 must be found.…”

“…The film preparation was performed as in our previous study . Briefly, 540 mg of lyophilized fibroin and 15 mg of lyophilized aloe gel extract were dissolved for 1 h in lactic acid solution (pH 4.0 ± 0.2), finalizing volume of 15 mL.…”

“…Our previous studies found that the blended fibroin/aloe gel extract film demonstrates potential healing effects, based on experimentations in vitro and in vivo in streptozotocin-induced diabetic rats, and clinical trials in diabetic foot ulcer patients. , Additionally, the γ-irradiated developed film enhanced the proliferation and migration of the healthy fibroblast cells. The presence of functional groups in the blended fibroin/aloe gel film, including amides (I, II, III), glucan units, pyranoside ring, and mannose, promotes tissue repair, but the underlying molecular mechanism is still unclear . In this present study, we explored the beneficial effects of the γ-irradiated blended fibroin/aloe gel extract film on cell biological activities and biomolecular mechanism(s) using normal dermal, diabetic dermal, and diabetic wound fibroblasts.…”