Biocompatible propylene glycol alginate-g-polytetrahydrofuran amphiphilic graft copolymers for highly effective drug carriers

Abstract

The acylated propylene glycol alginate-g-polytetrahydrofuran amphiphilic graft copolymers (APGA-g-PTHF) with various grafting numbers (GN) of 3–23 per 1000 monosaccharide rings and PTHF (PTMG or PTMO) branches with different molecular weights (Mn,PTHF) of 600–3400 g/mol could be successfully synthesized via nucleophilic substitution of PTHF living chains carrying oxonium ions with the –OH side groups of APGA backbone. The nanophase separation, the hydrophobicity and the surface roughness were increased due to the less restricted movement of hydrophobic PTHF branches to the surface. APGA-g-PTHF graft copolymers behave low cytotoxicity and good anti-protein performance. Interestingly, APGA-g-PTHF amphiphilic graft copolymers could form homogeneous nanospheres (<250 nm) via self-assembly in H2O/CH2Cl2 medium which could be used for drug (ibuprofen or curcumin) carriers having high drug loading efficiency (∼45%) and fast release behavior. The nanospheres carried curcumin behave very higher (10-fold) anticancer effect against HeLa cells than that of curcumin and thus reduce the harmful drug dosage. Moreover, the nanospheres carried drug might enter into HeLa cells and present pH-sensitive drug release. To the best of our knowledge, this is the first example of PGA-based graft copolymers for highly effective nano-carriers and anti-protein surfaces, which would have a prospect in biomedical areas.