Legends to figures
Figure 1. SEM images at lower (a, c, e) and higher (b, d, f)
magnification of the A-C hydrogels at different weight ratios: a-b)
0.5%-0.02%; c-d) 0.25%-0.02%; e-f) 0.125%-0.025%. Scale bar is 100
µm.
Figure 2. a) FTIR spectra of a hydrogel of only agarose (green
curve), collagen (pink curve) and a 0.25%-0.02% A-C hydrogel (red
curve). b) Swelling behaviour of the A-C hydrogels kept in PBS at 37 °C.
c-d) Degradation curves of the A-C hydrogels in PBS and in DMEM medium
with 10% FBS, respectively, up to 2 weeks. e-f) Diffusion tests
performed with Hyaluronic acid-FITC and Transferrin-TRITC, respectively,
up to one week.
Figure 3. Representative stress-strain curves of A-C hydrogels
subjected to unconfined compression with a displacement rate of 0.01
mm/s, until 80 % strain (A); Compressive moduli of A-C hydrogels at 0,
1, 4, 8 days of incubation in PBS at 37 °C, in humified atmosphere with
5% CO2 (B). Values represent mean ± SD, where n = 3.
Figure 4. The upper panels show the morphology and the size of
the spheroids obtained with MCF-7 and MDA-MB-361 cells grown in
0.25%-0.02% and 0.125%-0.02% A-C% hydrogels, respectively, from 2
to 14 days. The graphs report the growth trend of both cell lines.
Figure 5. Images of the tumor spheroids obtained with MCF-7,
MDA-MB-361 and SH-SY5 after 8 days growth in 0.125%-0.02% A-C% (upper
panels) and 0.25%-0.02% hydrogels (lower panels). The arrows point to
the disseminating cells of the spheroids grown in the soft matrix. Scale
bar is 100 µm.
Figure 6. Mitochondrial labelling of living spheroids after 5
days growth with Mitotracker red. Spheroids of MCF-7 and MBA-MB-361 were
stained and compared. Scale bar is 50 µm.
Figure 7. Staining of E-cadherin in cellular spheroids of MCF-7
and MBA-MB-361 after 5 days growth in A-C hydrogels. Scale bars
correspond to 57.6 µm.
Figure 8. Live dead assay performed with the MCF-7 spheroids
embedded into the A-C hydrogels after 24 h incubation with cisplatin.
The upper panels refer to the 0.25%-0.02% A-C hydrogels, while the
lower panels to those with 0.125%-0.02% A-C ratio. The graph reports
the number of live and dead cells in each sample estimated through the
distribution of the fluorescence signals of Calcein AM and Ethidium
Homodimer, respectively.
Figure 9. Images of MCF-7 spheroids grown within 0.25-0.02%
(upper panels) and 0.125-0.02% (lower panels) A-C matrices,
respectively, recovered after Agarase treatment, fixed and stained with
DAPI.