Fig. 2.

Characteristics of the collagen type I gel and ACM. (i) Collagen density of the acellular gel after partial and full compression. (ii) Growth rate of HT29 cells in 3-D collagen gels and on cell culture plates (2-D) obtained from the metabolic activity measured by Alamar Blue assay. (iii) Representation of the 3-D tumour model with inserted optic fibre probe measuring the oxygen level (light), (iv, v) Oxygen levels in the ACM populated with HT29 and surrounded by acellular collagen type I measured by tissue oxygenation monitoring: (iv) oxygen level in the core of the ACM and (v) oxygen level at the interface between the ACM and surrounding gel.