*2.6. CCP Average Molecular Mass Determination*

The CCP average molecular weight (Mw) and polydispersivity index (Pi) were determined by size exclusion chromatography (SEC) using an Agilent 1200 chromatographic system coupled with a G7162A Refractive Index Detector (RID) (Agilent Technologies, Santa Clara, CA, USA). Narrow pullulan standards in the 5−<sup>642</sup> × 103 g/mol range were used for the calibration curve (Waters Corporation, Milford, MA, USA). An Ultrahydrogel™ 2000 column (12 μm, 7.8 mm × 300 mm) and an Ultrahydrogel™ 250 column (6 μm, 7.8 mm × 300 mm) (Waters Corporation, Milford, MA, USA) were coupled in series and operated at a constant flow rate of 0.8 mL/min. The mobile phase consisted of a 0.1 M NaCl solution (*w*/*v*) containing 0.02% NaN3 (*w*/*v*), filtered through a 0.45 μm PTFE membrane (Merck-Millipore, Milan, Italy). Columns and detector were maintained at 40 ◦C.

Samples were prepared by dissolving CCP or pullulan standards in 0.1 M NaCl (1 mg/mL final concentration) and filtered (cellulose microporous membrane filter, 0.45 mm, Merck-Millipore, Milan, Italy) before injection (injection volume 50 μL).
