Evaluation of pressure dispersion and limited photosensitization of cell membrane perforators with hollow geometry

Recently, the control of cell function has attracted increasing attention, with the possibility of changing various morphological and functional forms of cells and organs. Cell modifications include virus vectors and lipofection methods; however, these approaches have limitations in terms of efficiency and process optimization. In contrast, our photochemical cell membrane perforation method exhibits high efficiency but requires a thermosetting silicone polymer-based cell membrane perforator as a consumable item, requiring a 4-h production time. Moreover, the success rate of cell perforation is low because of the application of uneven pressure on the cell population. In a previous study, we presented a process employing an injection-molding machine to manufacture thermoplastic elastomer-based perforators for mass production. This successfully shortened the production time to $\lt 1\mathrm{h}$ while preserving perforating function. Adopting a hollow shape to the perforator enabled the application of uniform pressure to the cell population. In addition, we successfully suppressed the unnecessary oxidative effects by limiting other photosensitizing functions. However, previous studies have not fully evaluated the perforation success rate by pressure dispersion of the cell population or by limiting the photosensitizing function. Therefore, in this study, we used human umbilical vein endothelial cells to introduce fluorescent substances and mRNA to evaluate the perforation success rate.