Stem cells are largely considered as deadly offspring of tumors nowadays, working silently while regulating disease progression and metastasis. Plenty of literatures identifies the cross-talk between the stem and cancer cells,¹, but petty hard evidence or models are available exploiting the impact of this cross-talk. Therefore, an attempt is made to uncover the effect of biochemical and mechanical properties on proliferation and spheroid formation ability of osteosarcoma cells in presence of adipose stem cells. Finding a biomimetic biomaterial to culture osteosarcoma cells other than collagen has challenged to the researchers. Silk is one of popular choice of biopolymer for bone tissue engineering² and easily be blended with other polymers, such as gellan gum. Blended hydrogels of silk - gellan gum with tunable chemical and mechanical properties are synthesized for co-culturing human osteosarcoma (Saos2) and adipose derived stem cells. The constructs are then screened for spheroid formation. The development of spheroids in selective hydrogel formulation is indicative of regulatory effect of biophysical cues in cancer development and progression. The heterogeneity lies within the present model (co-culture and blended matrix), highlights the diversity of cancerous niche, which is anticipated to evoke further study of screening of cancer chemotherapeutics, more precisely drugs targeted to the matrix.

Acknowledgement:This work is supported by the European Union Framework Programme for Research and Innovation Horizon 2020 under grant agreement nº 668983 — FoReCaST. VM Correlo acknowledges Investigator FCT program (IF/01214/2014)

References

1. Lindoso RS, Collino F, Vieyra A. Extracellular vesicles as regulators of tumor fate: crosstalk among cancer stem cells, tumor cells and mesenchymal stem cells. Stem Cell Investig 4,75, 2017.

2. Bhattacharjee P, Kundu B, Naskar D, Kim HW, Maiti TK, Bhattacharya D, Kundu SC. Silk scaffolds in bone tissue engineering: An overview. Acta Biomaterialia 63, 1, 2017.