In skin research, widely used in vitro 2D monolayer models do not sufficiently mimic physiological properties. To replace, reduce, and refine animal experimentation in the spirit of '3Rs', new approaches such as 3D skin equivalents (SE) are needed to close the in vitro/in vivo gap. Cell culture inserts to culture SE are commercially available, however, these inserts are expensive and of limited versatility regarding experimental settings. This study aimed to design novel cell culture inserts fabricated on commercially available 3D printers for the generation of full-thickness SE. A computer-aided design model was realized by extrusion-based 3D printing of polylactic acid filaments (PLA). Improvements in the design of the inserts for easier and more efficient handling were confirmed in cell culture experiments. Cytotoxic effects of the final product were excluded by testing the inserts in accordance with ISO-norm procedures. The final versions of the inserts were tested to generate skin-like 3D scaffolds cultured at an air-liquid interface. Stratification of the epidermal component was demonstrated by histological analyses. In conclusion, here we demonstrate a fast and cost-effective method for 3D-printed inserts suitable for the generation of 3D cell cultures. The system can be set-up with common 3D printers and allows high flexibility for generating customer-tailored cell culture plastics.
Keywords: 3D printing; PLA; full-thickness skin model; insert; tissue engineering.