Af2200 spectrophotometer

Gellan Gum (Gelrite^®®), sodium hydroxide (NaOH), tetramethylammonium chloride (TMACl), live dead staining kit were purchased from Sigma-Aldrich, Milan, Italy.
Fluorescein labelled dextran Anionic, Lysine Fixable (Dextran-FITC) (Mw 10 kDa) was purchased by Thermo Fisher Scientific, Milan, Italy.
MTS reagent (CellTiter 96^®® AQueous One Solution Cell Proliferation Assay) was purchased from Promega, Milan, Italy.
Hydrolysis was conducted using rotating heating plate equipped with an independent temperature control/detection system.
Size exclusion chromatography was conducted with an Agilent 1260 Infinity multi-detector GPC/SEC system.
SEM analysis was conducted using a Phenom XL by Alfatest microscope operating at 5 kV (Alfatest, Rome, Italy).
The rheological tests were carried out using a DHR-2 oscillatory rheometer equipped with a self-heating Peltier plate (TA instrument, Sesto San Giovanni, Italy).
Release studies were conducted with an UV-Vis spectrophotometer UV-240PC (Shimadzu, Salerno, Italy).
Cell cultures were performed using an Eppendorf New Brunswik S41i incubator, the viability was measured with Eppendorf AF2200 spectrophotometer.
Fluorescence images were obtained with AxioVert200 microscope (Zeiss, Milan, Italy).

¹H-NMR spectra were obtained with a Bruker Avance II 400 MHz spectrometer (Milan, Italy).
FT-IR spectra were obtained with Bruker Alpha in the wave number range of 400 and 4000 cm⁻¹ (Milan, Italy). SEM analyses were performed with Phenom Pro X Desktop (Thermo Fisher Scientific, Rome, Italy).
The rheological tests were carried out using a DHR-2 TA Instrument rotational rheometer (TA Instruments-Waters S.p.A., Sesto San Giovanni, Italy).
UV measurements were performed using an Eppendorf AF2200 spectrophotometer (Milan, Italy).
Cell cultures were performed using an Eppendorf New Brunswik S41i incubator (Milan, Italy).
Fluorescence images were obtained with an AxioVert200 (Zeiss) microscope (Milan, Italy).
A 3D printer Zmorph (Wroclaw, Poland) connected with a pressure controller OB1 working at pressures of 0–8000 mbar from Elveflow (Paris, France) was used to test printability of the inks.