Feasibility Study for the Use of Gene Electrotransfer and Cell Electrofusion as a Single-Step Technique for the Generation of Activated Cancer Cell Vaccines.

Cell-based therapies hold great potential for cancer immunotherapy. This approach is based on manipulation of dendritic cells to activate immune system against specific cancer antigens. For the development of an effective cell vaccine platform, gene transfer, and cell fusion have been used for modification of dendritic or tumor cells to express immune (co)stimulatory signals and to load dendritic cells with tumor antigens. Both, gene transfer and cell fusion can be achieved by single technique, a cell membrane electroporation. The cell membrane exposed to external electric field becomes temporarily permeable, enabling introduction of genetic material, and also fusogenic, enabling the fusion of cells in the close contact. We tested the feasability of combining gene electrotransfer and electrofusion into a single-step technique and evaluated the effects of electroporation buffer, pulse parameters, and cell membrane fluidity for single or combined method of gene delivery or cell fusdion. We determined the percentage of fused cells expressing green fluorescence protein (GFP) in a murine cell model of melanoma B16F1, cell line used in our previous studies. Our results suggest that gene electrotransfer and cell electrofusion can be applied in a single step. The percentage of viable hybrid cells expressing GFP depends on electric pulse parameters and the composition of the electroporation buffer. Furthermore, our results suggest that cell membrane fluidity is not related to the efficiency of the gene electrotransfer and electrofusion. The protocol is compatible with microfluidic devices, however further optimization of electric pulse parameters and buffers is still needed.

Heating and Strain Sensing Elements Based on Segregated Polyethylene/Carbon Black Composites in Polymer Welded Joints.

The development of easy and direct real-time monitoring of welded joint quality instead of surface damage analysis is crucial to improve the quality of industrial products. This work presents the results of high-density polyethylene (HDPE)-based composites with various carbon black (CB) content (from 20 to 30 vol.%) for use as a heating element and strain sensor in electrofusion-welded polymer joints. The pyroresistive heating process was used to determine the effect of generated Joule heat during welding on the structure and sensor properties of polymer-carbon composites. It is shown that the generation of Joule heat depends on the nanocarbon content and affects the crystallinity of the polymer matrix. The partial disruption of the conductive path of carbon black particles was observed and, as a result, a decrease in electrical conductivity for composites with lower CB content after welding was found. For the highest CB amount, conductivity increased, which is caused by smaller particle-to-particle distance for filler paths. Therefore, the best balance between pyroresistive and sensor properties was found.