RESUMO
Nowadays, metal-organic frameworks (MOFs) have emerged as promising tools for different biological applications and therefore, efforts are ongoing to develop more biocompatible MOFs-based nanocomposites. We aimed to fabricate some new conductive nanocomposites of polypyrrole and cobalt-MOF with different weight percentages (PPy/x%Co-MOF) using the solution mixing method and characterize them through FT-IR (Fourier-transform infrared), PXRD (powder X-ray diffraction), SEM (scanning electron microscope), and TEM (transmission electron microscope) techniques. The biocompatibility of nanocomposites was assessed by haemolytic, cytotoxic, and quantitative reverse transcription PCR (qRT-PCR) assays. FT-IR and PXRD results revealed that nanocomposites consisted of pure MOFs and PPy. Moreover, SEM results indicated their spherical morphology along with an average diameter of 190 nm. (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed a concentration, and percentagedependent cytotoxic effect of the nanocomposites on some cell lines including 3T3 fibroblasts, MCF-7, and J774.A1 macrophages. Haematological toxicity of PPy/x%Co-MOF composites was less than 7% in most concentrations. Furthermore, PPy/x%Co-MOF composites did not show any significant effect on the expression of cyclooxygenase-2( COX-2) and inducible nitric oxide synthase( iNOS) genes. In sum, regarding the haemolytic, proinflammatory, and cytotoxic tests, prepared nanocomposite demonstrated the reasonable in vitro biocompatibility which may be considered as a hopeful platform for further investigations including clinical applications.
RESUMO
The main objective of composite science is to fabricate new materials with desired properties such as high chemical, mechanical, and/or biological performances. In this research, new conductive nanocomposites of copper metal-organic frameworks (Cu-MOF) and polypyrrole (PPy) were fabricated with the aim of exploiting the electrical conductivity of polypyrrole and the porosity of MOFs in the final products. The prepared compounds (PPy/x%Cu-MOF, x = 20, 50, and 80) were investigated by FTIR, PXRD, SEM, TEM, DLS, BET, EDS mapping, cyclic voltammetry (CV), and zeta potential (ξ) measurements. Spherical morphology was confirmed by SEM and TEM analysis. The PPy/80%Cu-MOF nanocomposite showed the highest ξ potential (-40 mV), demonstrating the stability of dispersed particles. The CV results revealed that the nanocomposites have higher capacitance in comparison to the pure materials. In vitro degradation of the as-prepared compounds in simulated body fluid (SBF) was studied by EIS (electrochemical impedance spectroscopy) and Tafel polarization tests. Furthermore, in vitro biocompatibility of the PPy/x%Cu-MOF composite was evaluated on a group of cells including 3T3 fibroblasts, MCF-7 breast cancer cells, J774.A1 macrophages and red blood cells (RBCs). Viability of 3T3 fibroblasts, MCF-7, and J774.A1 cells, by Methylthiazolyldiphenyl-tetrazolium bromide (MTT) method, was dependent on Cu-MOF percent and amount of composites. Hemolytic assay for RBCs exposed to different amounts of the PPy/x%Cu-MOF composites showed hematological toxicity less than 5% in most concentrations. In addition, to investigate pro-inflammatory activity, J774.A1 macrophages were exposed to non-toxic concentrations of the PPy/x%Cu-MOF and no significant change in the expression of two inflammatory genes COX-2 and iNOS was observed. Injection of the PPy/x%Cu-MOF (5 mg kg-1) into bloodstream of mice did not increase liver damage marker enzymes alanine transaminase (ALT) and aspartate transaminase (AST) level in serum 1 week post injection. Moreover, we observed slight but not significant increase in serum copper level in mice 1 week after injection. According to the results, the PPy/x%Cu-MOF nanocomposites exhibited a good in vitro and in vivo biocompatibility without inducing pro-inflammatory responses in macrophages and show promising potential for different biomedical applications such as biosensors and drug delivery. The release of curcumin from curcumin-loaded PPy/x%Cu-MOF nanocomposites was detectable in plasma of mice 4 days after administration.
