*4.1. Materials*

Protosan UP CL 213, a chitosan salt that dissolves in water (CS, 75–90% deacetylated, 150–400 kDa) was sourced from NovaMatrix (Sandvika, Norway). Pharmaceutical grade *Fucus vesiculosus* fucoidan (FUC, Batch no. DPFVF2015505 from the Maritech ®® range, 98% purity, 1.4% uronic acid, 56.9 kDa, 26.6% sulfate 50.7% fucose) was supplied by Marinova Pty Ltd. (Cambridge, TAS, Australia). The purification of fucoidan to remove pyrogens produces a highly pure material that is acceptable for medical use. Human fibroblast growth factor-basic (FGF-2, 154 a.a.) was supplied by Peprotech-Lonza, Mt Waverley, VIC, Australia. Lysozyme from chicken egg white (LYZ, dialyzed, lyophilized, powder, 100000 <sup>U</sup>·mg<sup>−</sup>1) and polyethylenimine (PEI, branched, 25 kDa) and were obtained from Sigma-Aldrich, Australia.

Potassium chloride (KCl, 99%, AR) was purchased from Chem-Supply (Gillman, SA, Australia). The KCl was further purified to remove surface active impurities, by calcination at 550 ◦C for 8 h, followed by recrystalisation and finally, another calcination. Phosphate buffered saline (Dulbecco A) was obtained from Thermo Fisher Scientific, Adelaide, SA, Australia and used as supplied. HCl and KOH (both volumetric grade) were sourced from Merck KGaA, Darmstadt, Germany. Reagents used for cleaning surfaces include; ethanol 100% undenatured (AR, Chem-Supply, Gillman, SA, Australia), Hellmanex (Hellma Analytics, Müllheim, Germany), pH 7 Tickopur R 30 and OP-U colloidal silica suspension (Struers, Ballerup, Denmark).
