pH responsive metformin loaded zeolitic imidazolate framework (ZIF-8) for the treatment of lung cancer

A simple and cost-effective synthesis method for zeolitic imidazolate framework-8 (ZIF-8) was developed and loaded with metformin (MET@ZIF-8) for pH sensitive-release behaviour for the treatment of lung cancer. ZIF-8 and MET@ZIF-8 were subjected to particle size, zeta potential analysis and HR-TEM through which it shows evidence that the particles had spherical morphology and nanosize. Percentage of metformin (MET) loading in the ZIF-8 was found to be 63.39 +/- 1.32%. Dissociation of ZIF-8 into its coordination ions at acidic conditions (pH 5-6) thereby leads to the release of MET at a higher drug release rate (98%) compared to physiological conditions (pH 7.4) the drug release rate at 35%. Pore volume and pore size of ZIF-8 (1242 m(2)/g) gets reduced to 1042.00 m(2)/g after incorporation of MET in ZIF-8. In-vitro cytotoxicity assay results showed the enhanced cytotoxicity for MET @ZIF-8 compared to free MET in a dose dependent manner in human lung adenocarcinoma cells A549.

Automated summary

A simple and cost-effective synthesis method was developed for the treatment of lung cancer using pH sensitive-release behaviour of MET@ZIF-8. Analysis of particle size, zeta potential, and HR-TEM showed nanosize spherical morphology of the particles. The release rate of MET was higher at acidic conditions compared to physiological conditions, with pore volume and pore size reduction after MET incorporation in ZIF-8. In-vitro cytotoxicity assay results demonstrated enhanced cytotoxicity for MET@ZIF-8 in a dose-dependent manner.