Polyethyleneimine based Cerium(III) and Ce(NO3)3 metal-organic frameworks with blood compatible, antioxidant and antimicrobial properties

Abstract

Here, a well-known antibacterial cationic branched polyethyleneimine (PEI) is used as organic linker in the preparation of metal organic frameworks (MOFs) with a lanthanide salt, Cerium (III) nitrate (Ce(NO3)3) for two types of MOFs. One of the MOF is PEI-Ce(III) prepared from the aqueous solutions of PEI and Ce (III) ions at room temperature. The second MOF is prepared from the HCl treated PEI (p-PEI) and Ce(NO3)3 in ethanol as p-PEI-Ce(NO3)3 MOFs. The MOFs are prepared at 1: 0.25, 1:0.5 and 1:1 mol ratios of PEI repeating unit to Ce(III) ions and named as p-PEI-Ce(NO3)3–0.25, −0.5, and −1, respectively. The prepared PEI-Ce(III) MOFs are in powder form, whereas p-PEI-Ce(NO3)3 MOFs are sticky and viscous as gum and soluble in water. The surface areas of PEI-Ce(III) MOFs are found to decrease with the increase in the amount Ce(III) amount and maximum surface area is measured for PEI-Ce(III)-0.25 as 142.3 m2/g, while the surface area of p-PEI-Ce(NO3)3 MOFs cannot be measured. Additionally, all the PEI-Ce(III) MOFs are found blood compatible with < 0.5% hemolysis and >90% blood clotting index values up to 0.25 mg/mL concentration. Also, the antioxidant activity of PEI which is 1107 ± 26 Trolox Equivalent Antioxidant Capacity (TEAC mM/g) is retained as 166 ± 12, 186 ± 1.0, 194 ± 2.0 for p-PEI-Ce(NO3)3–0.25, −0.5, and −1 MOFs, respectively whereas no antioxidant activity in for Ce(III) is measured at the same concentrations. More importantly, the antimicrobial activity of PEI that is measured by via both micro-dilution and disc diffusion antimicrobial tests is also maintained for p-PEI-Ce(NO3)3 MOFs against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, and Candida albicans with the MIC values ranging 0.625–5.0 mg/mL and the MBC values of 1.25–10 mg/mL.