Study On The Mechanism Of The Sol-gel Bioactive Glass Regulating The Barrier Function Of Keratinocytes

As an important barrier of human body,skin plays an important role in protecting the body from unwanted influences from the environment and maintaining homeostasis.The barrier function of the skin is mainly composed of the stratum corneum and the tight junction between keratinocytes.Diabetic non-healing wound is a common complication of diabetes.With the increasing number of diabetic patients,the treatment of diabetic non-healing wound has become a clinical problem that attracts much attention.The keratinocytes dysfunction in the diabetic wounds can lead to re-epithelialization failure and hard to repair the structure and function of skin.Bioactive glass with high biological activity has been reported to be used for chronic wound healing.However,its effects on keratinocytes and skin barrier function have not yet been elucidated.In this article,the regulation and mechanism of sol-gel bioactive glass on keratinocytes and the barrier function of keratinocyte monolayer were investigated.Besides,the effects and mechanism of it on wound healing and barrier function remodeling were studied by in vivo experiment.It is expected to provide new ideas and theoretical basis for further study and clinical application of bioactive glass in skin wound healing.The proliferation,migration and differentiation of keratinocytes play an important role in wound healing.In this article,58 S sol-gel bioactive glass and the sol-gel bioactive glass extracts with different dilution ratios were firstly prepared.The sol-gel bioactive glass extracts were used to culture keratinocytes to explore the effects of sol-gel bioactive glass extracts on the morphology,proliferation and migration of keratinocytes.The results showed that the morphology of keratinocytes has changed after treatment with the sol-gel bioactive glass extracts:the intercellular space of keratinocytes decreased.Low concentration of sol-gel bioactive glass extracts had no obvious effect on cell proliferation.Sol-gel bioactive glass extracts had no significant effect on the migration rate of keratinocytes but promoted the collective migration of keratinocytes.Then,the effects of sol-gel bioactive glass on the in vitro barrier function of keratinocyte monolayer were investigated by using the transepithelial electrical resistance measurement and the paracellular tracer flux assay.The results showed that sol-gel bioactive glass extracts enhance the transepithelial electrical resistance and reduce the cell permeability.Sol-gel bioactive glass extracts can upregulate the expression of keratin 10 and involucrin and promote keratinocyte differentiation.Besides,sol-gel bioactive glass extracts promoted the expression of claudin-1 and occludin and tight junction assembly.These might be the mechanisms for sol-gel bioactive glass promoting the barrier function.Finally,the model of type I diabetic rats was constructed,and sol-gel bioactive glass extract was used in the full thickness wounds.The results showed that sol-gel bioactive glass extract could reduce the inflammatory response,promote the formation of new blood vessels and the differentiation of keratinocytes,accelerate the process of re-epithelialization,promote the formation of tight junction between keratinocytes in the wound site,and ultimately promote the recovery of skin structure and the restoration of barrier function.