pH --- Nanogel using pH sensitive block copolymer polyaspartic acid-graft-imidazole-polyethylene glycol and preparing method thereof

摘要

The present invention relates to a nanogel using a pH-sensitive block copolymer and poly(aspartic acid-graft-imidazole)-polyethylene glycol, and a preparation method for the same. More specifically, the pH-sensitive nanogel is prepared through a chemical crosslinking reaction between poly(aspartic acid-graft-imidazole)-polyethylene glycol and polyethylene glycol on which chemically modified bis-N-hydroxysuccinimide (bis-NHS) is grafted. In particular, the nanogel has appropriate physicochemical characteristics (appropriate pK_a value, a wide buffer zone, a nano size, a positive Zeta potential, and morphology) and pH-dependent characteristics and thus, by an electrostatic interaction due to the imidazole group turning positively charged, can control drug release and increase drug efficacy to a target cell in an acidic tumor microenvironment (between pH 7.2 and pH 6.5) through reversible swelling and endosome destruction. Accordingly, the nanogel using poly(aspartic acid-graft-imidazole)-polyethylene glycol having the above effects can be utilized as a composition for drug delivery for tumor treatment.