Visiting Professor Martin Viklund of Sweden's KTH Royal Institute of Technology will discuss a novel method for tissue and tumor micro-engineering that was developed in his lab in Stockholm. Based on ultrasound-supported three-dimensional (3-D) cell culture in a multi-well microplate, the method is gentle and can be used for producing various tissue-mimicking 3-D structures in parallel. It is based on ultrasonic-standing-wave particle manipulation inside hundreds of micro-wells in the microplate. The method consists of analysis and optimization of the driving parameters of the ultrasound transducer attached to the microplate, and demonstration of the production of various micro-engineered models of solid tumors. Vilund and his colleagues have primarily used cells from HepG2 hepatocellular carcinoma and A498 renal carcinoma cell lines as building blocks in the tumor models, but have also tested the method with fibroblasts, thyroid cells and melanoma cells.
The solid tumor models are characterized on-chip by detailed 3-D confocal and light-sheet microscopy, and off-chip with fluorescence-activated cell sorting (FACS). Furthermore, the team has developed an image analysis-based method for cell counting and characterization in 3-D, and have studied protein expression in tumor models by FACS, comparing 2-D and 3-D cultures. The selected proteins for the analysis are relevant ligands for natural killer (NK) cell recognition. The results show differences in protein expression levels between 2-D and 3-D cultures. This is of interest when optimizing future treatment protocols in NK cell-based cancer immunotherapy.