New ex vivo model in wound care highlights a natural skin regenerating booster
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Presented by: Gaëlle Saint-Auret
Introduction:
Wound healing is a complex mechanism which is implemented by the perfect coordination of 4 phases: hemostasis, inflammation, proliferation, and remodeling.
Hemostasis phase begins immediately after the injury. This phase controls the bleeding by vascular constriction and fibrin sealant. This early phase promotes the release of pro-inflammatory cytokines as well as growth factors such as platelet-derived growth factor (PDGF) and epidermal growth factor (EGF). Then, the inflammation phase occurs, controlling sequential infiltration of immune cells and cytokine release, including IL6. The proliferative phase focuses on covering the wound surface by re-epithelialization, repairing the vascular network and reconstructing granulation tissue. Thus, MMPs, PCNA and COL III are expressed to manage this phase. Finally, the remodeling phase improves wound contraction by transforming fibroblasts into myofibroblasts which express ACTA2.
Aims:
Excessive and prolonged inflammation promotes wound healing delay and excessive scaring. Thus, the switch between proinflammatory phase and skin reparative phase (proliferative and remodeling phases) is crucial. A skin wound healing model that mimics perfectly this delicate transition is a prerequisite to screen effective products that accelerate this process in accordance with consumers concerns.
Materials and Methods:
In this study a double excisional skin wound including dermis and epidermis has been optimized using standard biopsy punches (10 mm and 2 mm). In a first step, we investigated the natural repairing kinetic of this injury model by analyzing epidermis and dermis markers at mRNA and protein levels. In a second step, a promising cream was applied on punched skin explants every two days for 14 days to evaluate its regenerating properties.
Results and Interpretations:
We first highlighted that the inflammation/proliferative switch of the innovative wound healing model seems to be around 7 days after the injury. Thus, 7 days after the wound, the model exhibits the hallmarks of the inflammation phase by repressing the gene expression of ACTA2 (remodeling marker) as well as epidermal and dermal differentiation markers (EGF, LOR, LAMA5 and FLG) and over-expressing IL6 gene. Interestingly, 14 days later, our model displays characteristics of the early proliferative phase. Indeed, the gene expression of immature ECM proteins such as collagen III are increased. Moreover, the proliferative marker, PCNA is over-expressed at mRNA and protein level. Contrariwise, MMP3, that promotes fibroblasts migration into the wound, increased for 7 days after the wound, started to decrease at 14 days.
The development of cosmetic products able to optimize the switch between inflammation and proliferative phases is of interest to reduce keloids, contracture, hypertrophic scar, ….
In this study, we focused on a cream composed of a synergic combination of vegetable oils (Camelina sativa and Helianthus annuus), bud extract, which stimulates tissue regeneration and young shoots extracts (Hordeum vulgare and Oenothera biennis) which may have antioxidant properties. Previous studies suggested a promising efficiency in the skin rejuvenation.
In our model, 7 days after the wound, we observed that the cream treatment increased the gene expression of the proliferative phase marker, PCNA, and down-regulated MMP19 and MMP3 genes compared to the control untreated wound. An immunofluorescence staining of MMP3 proteins confirmed the previous results observed on gene expression. Thus, these results showed that the cream promotes entry into the proliferative phase from 7 days after the wound whereas untreated skin appeared to achieve these characteristics 14 days after the wound. Moreover, 14 days after the wound, the cream treatment allowed the skin to have all the characteristics of the remodeling phase by repressing the gene expression of COL3A1, COL1A1, PCNA, MMP3 and IL6 and inducing the gene expression of ACTA2 (remodeling marker) as well as epidermal differentiation markers (LOR).
Conclusion:
There is a constant endeavor to accelerate wound healing. This in vitro experimental wound healing model offers a novel approach to highlight product that can accelerate this process. Due to its unique composition, this very promising cream seems to save at least 7 days on the wound healing process.
Wound healing is a complex mechanism which is implemented by the perfect coordination of 4 phases: hemostasis, inflammation, proliferation, and remodeling.
Hemostasis phase begins immediately after the injury. This phase controls the bleeding by vascular constriction and fibrin sealant. This early phase promotes the release of pro-inflammatory cytokines as well as growth factors such as platelet-derived growth factor (PDGF) and epidermal growth factor (EGF). Then, the inflammation phase occurs, controlling sequential infiltration of immune cells and cytokine release, including IL6. The proliferative phase focuses on covering the wound surface by re-epithelialization, repairing the vascular network and reconstructing granulation tissue. Thus, MMPs, PCNA and COL III are expressed to manage this phase. Finally, the remodeling phase improves wound contraction by transforming fibroblasts into myofibroblasts which express ACTA2.
Aims:
Excessive and prolonged inflammation promotes wound healing delay and excessive scaring. Thus, the switch between proinflammatory phase and skin reparative phase (proliferative and remodeling phases) is crucial. A skin wound healing model that mimics perfectly this delicate transition is a prerequisite to screen effective products that accelerate this process in accordance with consumers concerns.
Materials and Methods:
In this study a double excisional skin wound including dermis and epidermis has been optimized using standard biopsy punches (10 mm and 2 mm). In a first step, we investigated the natural repairing kinetic of this injury model by analyzing epidermis and dermis markers at mRNA and protein levels. In a second step, a promising cream was applied on punched skin explants every two days for 14 days to evaluate its regenerating properties.
Results and Interpretations:
We first highlighted that the inflammation/proliferative switch of the innovative wound healing model seems to be around 7 days after the injury. Thus, 7 days after the wound, the model exhibits the hallmarks of the inflammation phase by repressing the gene expression of ACTA2 (remodeling marker) as well as epidermal and dermal differentiation markers (EGF, LOR, LAMA5 and FLG) and over-expressing IL6 gene. Interestingly, 14 days later, our model displays characteristics of the early proliferative phase. Indeed, the gene expression of immature ECM proteins such as collagen III are increased. Moreover, the proliferative marker, PCNA is over-expressed at mRNA and protein level. Contrariwise, MMP3, that promotes fibroblasts migration into the wound, increased for 7 days after the wound, started to decrease at 14 days.
The development of cosmetic products able to optimize the switch between inflammation and proliferative phases is of interest to reduce keloids, contracture, hypertrophic scar, ….
In this study, we focused on a cream composed of a synergic combination of vegetable oils (Camelina sativa and Helianthus annuus), bud extract, which stimulates tissue regeneration and young shoots extracts (Hordeum vulgare and Oenothera biennis) which may have antioxidant properties. Previous studies suggested a promising efficiency in the skin rejuvenation.
In our model, 7 days after the wound, we observed that the cream treatment increased the gene expression of the proliferative phase marker, PCNA, and down-regulated MMP19 and MMP3 genes compared to the control untreated wound. An immunofluorescence staining of MMP3 proteins confirmed the previous results observed on gene expression. Thus, these results showed that the cream promotes entry into the proliferative phase from 7 days after the wound whereas untreated skin appeared to achieve these characteristics 14 days after the wound. Moreover, 14 days after the wound, the cream treatment allowed the skin to have all the characteristics of the remodeling phase by repressing the gene expression of COL3A1, COL1A1, PCNA, MMP3 and IL6 and inducing the gene expression of ACTA2 (remodeling marker) as well as epidermal differentiation markers (LOR).
Conclusion:
There is a constant endeavor to accelerate wound healing. This in vitro experimental wound healing model offers a novel approach to highlight product that can accelerate this process. Due to its unique composition, this very promising cream seems to save at least 7 days on the wound healing process.