Design and Synthesis of a Biocompatible 1D Coordination Polymer as Anti-Breast Cancer Drug Carrier, 5‑Fu: In Vitro and in Vivo Studies

Designable coordination polymers
with suitable chemical diversities and biocompatible structures have
been proposed as a promising class of vehicles for drug delivery systems.
Here, we hydrothermally synthesized a novel one-dimensional (1D) coordination
polymer, [Zn­(H2O)6K2(H2BTC)2(H2O)4]­(H2BTC)2·2H2O, where H3BTC = benzene-1,3,5-tricarboxylic
acid (trimesic acid), cp.1. As the hydrogen bonds stabilized
1D chains in three dimensions, the cp.1 could be a good
candidate for delivering small-molecule chemotherapeutics such as
5-fluorouracil (5-Fu). The synthesized cp.1 showed a
remarkable 5-Fu loading of 66% with encapsulation efficiency of 98%
and almost complete release process. The 5-Fu-loaded cp.1 displayed a time-dependent cytotoxicity effect against breast cancer
cell lines MCF-7 and 4T1. The cellular uptake of cp.1 particles was investigated via confocal laser scanning microscopy
using fluorescein isothiocyanate and LysoTracker Red staining. Furthermore,
the in vivo antitumor impact of 5-Fu-loaded cp.1 was
studied on 4T1 breast cancer BALB/c mice model. The intratumor treatment
of 5-Fu-loaded cp.1 demonstrated beneficial antitumor
efficacy by postponing tumor growth. These results suggest that the
5-Fu-loaded cp.1 microparticles with a great locoregional
delivery can be efficient anticancer drug carriers for further clinical
treatments.