Fig. 1. Synthesis routine and physical characterizations of NCMNP2a-x polymers. (A) General schematic reaction for producing low Tris-grafting polymers (x = 5, 25 and 50). (B) General schematic reaction for producing high Tris-grafting polymer (x = 70). (C) Influence of Tris incorporation on the solubility of NCMNP2a-x (0.05% w/v) in the standard buffers containing 100 mM NaCl at various pH values. (D) A comparison of various NCMNP2a-x (0.05% w/v) in response to increasing quantities of divalent cation Ca²⁺. Absorbance increase corresponds to polymer aggregates because of inter- and intermolecular binding of polymer chains to Ca²⁺.