Table 2.

Difficulties and solution for scaling up the fabrication of injectable hydrogels.

Difficulties in Scaling up	Suggested Solutions
Rheological parameters	Rheological fluid behavior must be normalized to foresee the flow behaviors by comparison with the common standardization function (master curve) and to predict non-Newtonian fluid parameters based on Newtonian models
Mixing/dispersing of the hydrogel precursor	Adjust the propeller/dispersor configuration
Process time	Perform dimensional analysis based on Reynolds and Archimedes numbers
Process temperature	Sensors and software to control temperature depending chemical processes
Purification of the hydrogel	Comercial solution for scaling up purification steps
Filling of syringes with the hydrogel	Check the rheological properties of the pre-sterilized hydrogel in order to select the filling machinery