Smart dendrimer-based nanogel for enhancing 5-fluorouracil loading efficiency against MCF7 cancer cell growth

Nano-carriers are not only evaluated as a novel kind of drug delivery, but also expected to bypass the critical bottleneck of conventional cancer chemotherapeutics. Among them, thermo-sensitive nanogel draws much attention due to its efficacy in the loading and release of hydrophobic drugs. In the study, we developed a promising thermosensitive polymer-grafted dendrimer to enhance drug-loading efficiency, which was prepared from conjugation of thermo-sensitive carboxylic-terminated poly(N-isopropylacrylamide) polymer (PNIPAM) with polyamidoamine (PAMAM) dendrimer (G3.0). The obtained copolymer structure and molecular weight were confirmed by proton nuclear magnetic resonance ( (1) H NMR) and gel permeation chromatography (GPC), respectively. Morphology of the nanocarrier was observed around 120-150 nm by transmission electron microscopy (TEM) and 200 nm by dynamic light scattering (DLS). The nanocarrier exhibited the higher drug loading (DL = 7.79%) and entrapment efficiency (EE = 42.25%) of 5-FU compared to PAMAM dendrimer G3.0 (DL = 2.25% and EE = 11.52%). In-vitro test, the 5-FU-loaded in PAMAM G3.0-PNIPAM could release approximately 40% of the encapsulated drug at pH = 7.4 after 5 days tracking, while the cumulative anticancer drugs achieved nearly two-fold increase (around 75%) at pH 5.5 during the same time. Moreover, the cytotoxicity assay results also indicated that the drug-loaded nanocarrier exhibited a significant growth inhibition of the MCF-7 cancer cell. The obtained resulted possibly offered a great potential of the nanocarrier which may be utilized in delivering other anticancer drugs or dual drugs for chemotherapy in future.