(182s) Frozen Films: Porous Thin Films for in Vitro Culture

The development of new chemotherapies is a costly process that often uses 2D cultures for pre-clinical trials. The 2D cultures do not resemble the in vivo conditions, resulting in responses that differ from in vivo conditions. The use of 3D cultures for screening cancer cell cultures provides enhanced responses compared with 2D cultures. Biomaterial films and scaffolds are used for cancer cell culture, but each format has limitations. Consequently, we invented frozen films, a porous thin film with varied pore structure with film thickness. The frozen films combine the benefits of 2D and 3D cultures in a hybrid structure. The frozen films were prepared from a 1 wt% chitosan solution. The solution was spread on glass coverslips, frozen at -20 °C, and freeze dried to produce the porous structure. The chitosan films were neutralized with 1 M sodium hydroxide, then sterilized with 70% ethanol, followed by washing with excess D-PBS. The frozen films were compared with 2D films and 3D porous scaffolds prepared from 1 wt% chitosan solution. The frozen film micron-scale pore size increased with increasing film thickness. MDA-MB-231 cells were cultured on frozen films with different thicknesses and demonstrated different responses with respect to film thickness. Cells cultured on the thicker frozen films had a similar response to 3D porous scaffolds, while those cultured on the thinner frozen films had a similar response to 2D films. The frozen films supported MDA-MB-231cell growth during the seven day culture and had greater cell numbers with lower film thickness. Further characterization of the cultures is needed to assess the cell response to the frozen film structure. Future work will develop these frozen films into an in vitro cell culture platform for drug screening and evaluation of patient-derived tumor cells.