Heterodimeric nanoparticles comprising materials with different functionalities are of great interest for fundamental research and biomedical/industrial applications. In this work, Fe₃O₄-Au nano-heterostructures were synthesized by a one-step thermal decomposition method. The hybrid nanoparticles comprise a highly crystalline 12 nm magnetite octahedron decorated with a single noble metal sphere of 6 nm diameter. Detailed analysis of the nanoparticles was performed by UV-visible spectroscopy, magnetometry, calorimetry and relaxometry studies. The cytotoxic effect of the nanoparticles in the human hepatic cell line Huh7 and PLC/PRF/5-Alexander was also assessed. These Fe₃O₄-Au bifunctional nanoparticles showed no significant cytotoxicity in these two cell lines. The nanoparticles showed a good theranostic potential for liver cancer treatment, since the r₂ relaxivity (166.5 mM⁻¹·s⁻¹ and 99.5 mM⁻¹·s⁻¹ in water and HepG2 cells, respectively) is higher than the corresponding values for commercial T₂ contrast agents and the Specific Absorption Rate (SAR) value obtained (227 W/g_Fe) is enough to make them suitable as heat mediators for Magnetic Fluid Hyperthermia. The gold counterpart can further allow the conjugation with different biomolecules and the optical sensing.

In this work, we adapted a method for isolation of a highly purified fraction of mitochondrial DNA from muscle tissues suitable for further sample preparation of libraries without an amplification step for sequencing tasks on various NGS platforms and a method for evaluating the purity of DNA from contamination by nuclear genome regions. We optimized several techniques ^7,8 for enrichment of the mitochondrial fractions and purifying mtDNA. Here, we describe a protocol that allows getting from 80-100 mg of muscle tissues up to 1000 ng mtDNA, almost free from impurities of RNA and fragments of the nuclear genome.To assess the degree of purity of human mtDNA fraction from impurities of the nuclear genome, we adapted the PCR-screening technique ⁷ for the beta-actin gene region and AluSx-repeats in the human genome. This methodology avoids false-heteroplasmy calls (PCR biases or NUMT contamination) that occur when long-range PCR amplification is used for mtDNA enrichment.