Micropatterned κ-carrageenan-PVP-PEG hydrogels as a templet for head and neck cancer spheroid culture

Hydrogels have been demonstrated to exhibit distinct efficacy as matrices for 3D cell culture. As this research field advances, the needs for matrices combining both the benefits of natural and synthetic polymer hydrogels are becoming more apparent. In this study, kappa-carrageenan-PVP-PEG (κCA-PVP-PEG) hydrogels have been micropatterned with microwells to enhance human squamous carcinoma (HTB43™) spheroid growth. It was found that the hydrogels’ swelling ratios (SR) were 11.91, 11.67, and 11.67 for day 2, day 4, and day 8, respectively. A stable SR indicated no further swelling of hydrogels in the cell culture media, hence allowing spheroid growth in an intact mold without the rupture or dissolution of microwell templet. The comparison between unirradiated and irradiated hydrogel Fourier transform infrared (FTIR) spectra showed a slight shift of O-H (stretch) from 3,327 to 3,382 cm−1 and CH and CH2 (stretch) from 2,919 to 2,921 cm−1, respectively, whereas other functional peaks remained unchanged, suggesting the formation of interpenetrating network as the primary mechanism for hydrogels formation. The morphological study revealed the spherical shape of spheroids with measurements between 130 and 220 µm. Spheroids emit a signal in 4′,6-diamidino-2-phenylindole (DAPI) and fluorescein isothiocyanate (FIT-C) channels indicating spheroid viability. In conclusion, micropattern κCA-PVP-PEG hydrogels deemed suitable as a templet for generation and HTB43™ spheroid growth for 3D cell culture application.