Transdermal delivery is an attractive alternative, but it is limited by the extremely low permeability of skin. To solve this problem, a novel means--micro needle array based on micro electro-mechanical system （MEMS...Transdermal delivery is an attractive alternative, but it is limited by the extremely low permeability of skin. To solve this problem, a novel means--micro needle array based on micro electro-mechanical system （MEMS） technology, is provided to increase permeability of human skin with efficiency, safety and painless delivery. The fabrication method consists of a sequence of deep-reactive ion etching （DRIE）, anisotropic wet etching and conformal thin film deposition. The novel technology can enable the realization of micro fabricated micro needle array on a flexible silicon substrate. The micro needle array can be mounted on non-planar surface or even on flexible objects such as a human fingers and arms. The fabricated hollow wall straight micro needles are 200 μm in length, 30 μm inner diameter, and 50 μm outer diameter with 250 μm center-to-center spacing. Flow rate test proves that the polymeric base construction is important to function of micro needles array in package. Glucose solvent tests show that surface tension is the dominant force to affect the characters of flow in micro needles channel.展开更多
Hollow needle array-based tissue nanotransfection(TNT)presents an in vivo transfection approach that directly translocate exogeneous genes to target tissues by using electric pulses.In this work,the gene delivery proc...Hollow needle array-based tissue nanotransfection(TNT)presents an in vivo transfection approach that directly translocate exogeneous genes to target tissues by using electric pulses.In this work,the gene delivery process of TNT was simulated and experimentally validated.We adopted the asymptotic method and cell-array-based model to investigate the electroporation behaviors of cells within the skin structure.The distribution of nonuniform electric field across the skin results in various electroporation behavior for each cell.Cells underneath the hollow microchannels of the needle exhibited the highest total pore numbers compared to others due to the stronger localized electric field.The percentage of electroporated cells within the skin structure,with pore radius over 10 nm,increases from 25%to 82%as the applied voltage increases from 100 to 150 V/mm.Furthermore,the gene delivery behavior across the skin tissue was investigated through the multilayer-stack-based model.The delivery distance increased nonlinearly as the applied voltage and pulse number increased,which mainly depends on the diffusion characteristics and electric conductivity of each layer.It was also found that the skin is required to be exfoliated prior to the TNT procedure to enhance the delivery depth.This work provides the foundation for transition from the study of murine skin to translation use in large animals and human settings.展开更多
基金This project is supported by National Hi-tech Research and Development Program of China(863 Program, No.2005AA404220).
文摘Transdermal delivery is an attractive alternative, but it is limited by the extremely low permeability of skin. To solve this problem, a novel means--micro needle array based on micro electro-mechanical system （MEMS） technology, is provided to increase permeability of human skin with efficiency, safety and painless delivery. The fabrication method consists of a sequence of deep-reactive ion etching （DRIE）, anisotropic wet etching and conformal thin film deposition. The novel technology can enable the realization of micro fabricated micro needle array on a flexible silicon substrate. The micro needle array can be mounted on non-planar surface or even on flexible objects such as a human fingers and arms. The fabricated hollow wall straight micro needles are 200 μm in length, 30 μm inner diameter, and 50 μm outer diameter with 250 μm center-to-center spacing. Flow rate test proves that the polymeric base construction is important to function of micro needles array in package. Glucose solvent tests show that surface tension is the dominant force to affect the characters of flow in micro needles channel.
基金This work was supported in part by National Institutes of Health(NIH)grant(No.DK128845)Department of Defense grant(Nos.W81XWH-21-1-0097,W81XWH-21-1-0033,and W81XWH-20-1-251)to C.K.S,NIH grant(No.GM143572)to Y.X,and NIH grant(No.DK129592)to S.G.
文摘Hollow needle array-based tissue nanotransfection(TNT)presents an in vivo transfection approach that directly translocate exogeneous genes to target tissues by using electric pulses.In this work,the gene delivery process of TNT was simulated and experimentally validated.We adopted the asymptotic method and cell-array-based model to investigate the electroporation behaviors of cells within the skin structure.The distribution of nonuniform electric field across the skin results in various electroporation behavior for each cell.Cells underneath the hollow microchannels of the needle exhibited the highest total pore numbers compared to others due to the stronger localized electric field.The percentage of electroporated cells within the skin structure,with pore radius over 10 nm,increases from 25%to 82%as the applied voltage increases from 100 to 150 V/mm.Furthermore,the gene delivery behavior across the skin tissue was investigated through the multilayer-stack-based model.The delivery distance increased nonlinearly as the applied voltage and pulse number increased,which mainly depends on the diffusion characteristics and electric conductivity of each layer.It was also found that the skin is required to be exfoliated prior to the TNT procedure to enhance the delivery depth.This work provides the foundation for transition from the study of murine skin to translation use in large animals and human settings.
