Thermo-responsive methylcellulose hydrogels as temporary substrate for cell sheet biofabrication

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Cell Biology

Background:

• Cell culture techniques often rely on enzymes for cell detachment, which can affect cell viability and function.
• Temporary, thermo-responsive substrates are desirable for non-invasive cell harvesting.
• Methylcellulose (MC) is a cellulose derivative with potential thermo-responsive characteristics.

Purpose of the Study:

• To investigate methylcellulose (MC)-based hydrogels as thermo-responsive temporary substrates for cell culture.
• To determine the influence of MC concentration and salt composition on hydrogel properties.
• To evaluate the potential for enzyme-free cell sheet detachment using these hydrogels.

Main Methods:

• MC hydrogels were prepared using varying concentrations (2-12% w/v) and salts (Na2SO4, sodium phosphate, CaCl2, PBS).
• Gelation temperatures were determined using the inversion test.
• Thermo-mechanical properties and reversibility were analyzed via rheological studies.
• In vitro cytotoxicity was assessed using L929 mouse fibroblasts.
• Cell sheet detachment was induced and observed at 37°C.

Main Results:

• Hydrogel gelation temperature and rheological behavior were dependent on MC and salt concentrations.
• No cytotoxic effects were observed from the tested MC hydrogels.
• An 8% w/v MC hydrogel with 0.05 M Na2SO4 exhibited thermo-reversibility at 37°C.
• This specific formulation facilitated the spontaneous, enzyme-free detachment of a continuous cell sheet.

Conclusions:

• Methylcellulose hydrogels can be engineered with tunable thermo-responsive properties.
• The 8% MC/0.05 M Na2SO4 formulation is a promising candidate for cell sheet engineering.
• This thermo-responsive system allows for non-enzymatic cell detachment, preserving cell integrity.