Specific pH-Responsive Folate-Conjugate Microgels Designed for Antitumor Therapy

Colloidal nanosized folate-conjugated hydrogels for targeted chemotherapy were prepared via a versatile and efficient postsynthetic modification pathway starting from P(NPA-co-NIPAM). The modifications included the introduction of 4-methylpyridine as pH-sensitive pendant groups and the conjugation of folic acid to the microgel network. The microgels showed a specific swelling at pH < 6 (endosomes) as judged by DLS studies varying the external pH. The relative composition of the microgels shows a clear influence on the pH volume transition shifting. The potential of the microgels for anticancer drug release at pH = 5.0 was confirmed. Therefore, they are a promising targeting carrier for improved anticancer chemotherapy.