Design and comparison of the drug delivery systems of pegylated doxorubicin loaded Zn-CP and Zn-CP-SO₃H

In this investigation, a zinc coordination polymer of 5-aminoisophtalic acid [Zn(AIP)(DMSO)]_n called (Zn-CP) was employed as a drug delivery system. The surface of Zn-CP was modified with an acidic SO₃H group, and its capability for doxorubicin (Dox) delivery was compared to unmodified Zn-CP. The stability, specificity, cellular solubility, and loading/release process as well as the capability of inducing late apoptosis in MCF7 cells were improved through the pegylation of Dox-loaded carriers. The morphology of the designed carriers was evaluated using different analytical methods. Functionalizing the surface of Zn-CP with an acidic group increases its water solubility, drug loading, controlled release, and biocompatibility. The Dox loading and loading efficiency for Zn-CP@PEG were 28.8, and 40.6%, respectively, whereas, for Zn-CP-SO₃H@PEG were 33.0, and 51.2%, respectively. Zn-CP-SO₃H has a higher capacity of Dox loading than Zn-CP and Dox@Zn-CP-SO₃H@PEG has more control over the drug release as well as better specificity toward the cancerous cells of MCF7 than the surface unmodified carrier. The cytotoxicity study shows that modification of the Zn-CP surface with acidic groups of SO₃H decreases its cytotoxicity. The Dox@Zn-CP@PEG and Dox@Zn-CP-SO₃H@PEG exhibited high cytotoxic activity against cancer cells of MCF7, and remarkably low toxicity to normal breast cells of MCF10.