Friedreich ataxia (FRDA) is caused by the reduced expression of the mitochondrial protein frataxin (FXN) due to an intronic GAA trinucleotide repeat expansion in the FXN gene. Although FRDA has no cure and few treatment options, there is research dedicated to finding an agent that can curb disease progression and address symptoms as neurobehavioral deficits, muscle endurance, and heart contractile dysfunctions. Because oxidative stress and mitochondrial dysfunctions are implicated in FRDA, we demonstrated the systemic delivery of catalysts activity of gold cluster superstructures (Au8-pXs) to improve cell response to mitochondrial reactive oxygen species and thereby alleviate FRDA-related pathology in mesenchymal stem cells from patients with FRDA. We also found that systemic injection of Au8-pXs ameliorated motor function and cardiac contractility of YG8sR mouse model that recapitulates the FRDA phenotype. These effects were associated to long-term improvement of mitochondrial functions and antioxidant cell responses. We related these events to an increased expression of frataxin, which was sustained by reduced autophagy. Overall, these results encourage further optimization of Au8-pXs in experimental clinical strategies for the treatment of FRDA.

Acrylic colors are mixtures of several components that can be identified as pigments, binders, and fillers, so that, when analyzed, the characteristic response of the different components may not be recognizable. This limits the accuracy of spectroscopic techniques, nonetheless particularly useful as they are noninvasive and can be applied in situ on real artworks. Here, a method is proposed to chemically separate and identify the different components of acrylic colors, in order to be able to study their spectroscopic response separately, in particular by ultraviolet–visible–near-infrared diffuse reflectance. The results clearly show that the chemical and analytical method developed here is fully reliable, with the advantage of clearly separating the response of the different components without any change of their chromatic/chemical properties. As a case study, the new method is applied here to original acrylic colors used by the Italian artist Ico Parisi, in view of building a spectra database.

Upon aging and exposure to ambient conditions, acrylic colors get dry and the degree of polymerization of the polymer matrix increases due to progressive cross-linking. When interested in studying acrylic colors, separation of the different components, namely matrix, pigments, and fillers, may be particularly useful for their identification and characterization. In the case of aged acrylic colors, as found in artworks themselves or in materials present in artist studios, the separation approaches requiring chemical treatments of fluid samples cannot be applied. To overcome this limit, here a controlled combustion strategy is developed for eliminating the polymer matrix from the color and then recovering a powder made of pigments and fillers, which is analyzed by optical spectroscopy and demonstrated to display the same chromatic/chemical properties of the original color. As a case study, the new method is successfully applied to acrylic colors used by the Italian artist Domenico “Ico” Parisi (1916–1996), found in the original tubes in his studio.