Cerium oxide nanoparticles: the regenerative redox machine in bioenergetic imbalance.

AIM: Owing to their catalytic properties as reactive oxygen species scavengers, cerium oxide nanoparticles (nanoceria) have become an extremely promising candidate for medical applications, especially in the treatment of diseases where oxidative stress has been proposed as one of the main pathogenesis factors. MATERIALS & METHODS: In this work, nanoceria antioxidant power has been tested in primary cultured skin fibroblasts, derived from healthy individuals, by evaluating the mitochondrial function both in basal condition and after an oxidative insult. RESULTS & CONCLUSION: Combined with a clear lack of toxicity, antioxidant activity makes nanoceria promising in a wide range of clinical applications sharing the common signature of a global bioenergetic dysfunction.

Boron nitride nanotubes and primary human osteoblasts: in vitro compatibility and biological interactions under low frequency ultrasound stimulation.

In this paper we investigated a novel and non-invasive approach for an endogenous osteoblast stimulation mediated by boron nitride nanotubes (BNNTs). Specifically, following the cellular uptake of the piezoelectric nanotubes, cultures of primary human osteoblasts (hOBs) were irradiated with low frequency ultrasound (US), as a simple method to apply a mechanical input to the cells loaded with BNNTs. This in vitro study was aimed at investigating the main interactions between hOBs and BNNTs and to study the effects of the 'BNNTs + US' stimulatory method on the osteoblastic function and maturation.A non-cytotoxic BNNT concentration to be used in vitro with hOB cultures was established. Moreover, investigation with transmission electron microscopy/electron energy loss spectroscopy (TEM/EELS) confirmed that BNNTs were internalized in membranal vesicles. The panel of investigated osteoblastic markers disclosed that BNNTs were capable of fostering the expression of late-stage bone proteins in vitro, without using any mineralizing culture supplements. In our samples, the maximal osteopontin expression, with the highest osteocalcin and Ca(2+) production, in the presence of mineral matrix with nodular morphology, was observed in the samples treated with BNNTs + US. In this group was also shown a significantly enhanced synthesis of TGF-ß1, a molecule sensitive to electric stimulation in bone. Finally, gene deregulations of the analyzed osteoblastic genes leading to depletive cellular effects were not detected. Due to their piezoelectricity, BNNT-based therapies might disclose advancements in the treatment of bone diseases.

Oxidative stress biomarkers in mitochondrial myopathies, basally and after cysteine donor supplementation.

Mitochondrial diseases are due to impairment of the mitochondrial respiratory chain. A plausible pathogenic mechanism leading to cellular dysfunction and phenotypic expression is oxidative stress, but there are surprisingly few clinical studies on this subject. Glutathione (GSH) deficiency has been reported in mitochondrial diseases, and the biosynthesis of glutathione depends on cysteine availability. We have examined oxidative stress biomarkers [advanced oxidation protein products (AOPP) and ferric reducing antioxidant power (FRAP)] in blood samples from 27 patients and 42 controls. AOPP levels were greater in patients than in controls (P value <0.00001). Therefore, we performed a double-blind cross-over study to evaluate if 30-day supplementation with a whey-based cysteine donor could modify these markers, reduce lactate concentration during aerobic exercise, or enhance muscular strength and quality of life. Treatment did not modify lactate concentration, clinical scale (MRC) or quality of life (SF-36), but significantly reduced oxidative stress levels. Our findings reinforce the notions that in mitochondrial diseases oxidative stress is important and can be reduced by administration of a cysteine donor. Oxidative stress biomarkers may be useful to detect redox imbalance in mitochondrial diseases and to provide non-invasive tools to monitor disease status.