3D bioprinting has emerged as a promising technology for fabricating artificial tumors as it allows the fabrication of complex models recreating tumor physiology. The importance of the extracellular matrix (ECM) in tumor progression, cancer cells and stromal cells crosstalk and drug resistances, has motivated the development of more biomimetic tumor-ECM bioinks that recapitulate the high complexity of the ECM.1 In this regard, decellularized tissues-derived matrices (TDMs) can provide the native tissue biological cues, but its inadequate mechanical properties prevent their bioprinting. The aim of this work is to develop a breast TDM-like bioink suitable for bioprinting breast cancer models without the need of a sacrificial material.
Porcine breast tissues were decellularized and delipidated, and its composition was studied. TDMs pre-gels were fabricated by digesting it with pepsin and neutralizing the pH. The addition of rheological modifiers into the bioink was also assayed. TDM bioinks were printed with a 3D bioplotter (RegenHU) and then crosslinked. The bioinks were further tuned by incorporating an ECM protein overexpressed in breast cancer, Collagen type 1 (Col1). The shape fidelity, printability and rheological properties of the bioinks were characterized and the hydrogels Young modulus was measured. For bioprinting artificial breast tumors, cell-laden bioinks were prepared by dispersing breast cancer cells (BCCs) or mesenchymal stem cells in the bioink. Cellular survival, proliferation, morphology, and the expression of adhesion molecules were studied. The bioprinted hydrogels were used to study the efficacy of anticancer drugs.
Breast TDMs were successfully decellularized and rich in glycosaminoglycans and collagen. The addition of rheological modifiers allowed the TDM bioprinting without the requirement of any sacrificial material. BCCs were able to proliferate in TDM bioprinted scaffolds and form spheroids with a low expression of e-cadherin. The addition of Col1 improved the bioink printability, increases cellular proliferation and reduces doxorubicin sensitivity. TDM bioinks also allowed BCCs and stromal cells bioprinting and therefore could be used to fabricate artificial tumors.
Taken together, we have proved that TDM bioinks could be used for bioprinting artificial breast tumors closely recreating the tumor ECM.
European Union’s Horizon 2020 (Marie Skłodowska-Curie 712754), Spanish Ministry of Economy and Competitiveness (SEV-2014-0425, CEX2018-000789-S), FEDER and Spanish Ministry of Science, Innovation and Universities (RTI2018-096320-B-C21; MAT2015-68906-R), Spanish Ministry of Economy, Industry and Competitiveness (EUIN2017-89173), European Commission (JTC2018-103).
1. Bahcecioglu, G. et al., Acta Biomater. 106, 1-21 (2020).