A major challenge to turn the potential of carbon nanotubes (CNTs) into customer applications is to reduce or eliminate their toxicity. Taking into account health and safety concerns, intensified research efforts have been conducted to improve the biocompatibility of CNTs, including the development of new shortening and purification strategies. Ideally, the methods used for improving the biocompatibility of CNTs should not alter the electronic properties of CNTs. Herein, we report on the shortening of a sample containing single-walled and double-walled CNTs using steam and obtain new insights in the properties of the steam-treated CNTs. The present study shows that short CNTs (median length ca. 200 nm) can be obtained under the reported conditions. Raman analysis reveals that wider and outer nanotubes undergo more significant changes than the narrower and inner ones, especially after a prolonged steam treatment. ; The research leading to these results has received fundingfrom the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7/2007–2013/under REA grant agreement n8 290023 (RADDEL). ICN2 ac-knowledgessupport from the Severo OchoaProgram(MINECO, Grant SEV-2013-0295), and M. Kalbacthe support from MSMTproject LL1301. M. Kierkowicz and E. Pach are enrolled in the PhD Program in Materials Science at UAB. ; Peer reviewed
Idiopathic Parkinson's disease (iPD) and type 2 diabetes mellitus (T2DM) are chronic, multisystemic, and degenerative diseases associated with aging, with eventual epidemiological co-morbidity and overlap in molecular basis. This study aims to explore if metabolic and mitochondrial alterations underlie the previously reported epidemiologic and clinical co-morbidity from a molecular level. To evaluate the adaptation of iPD to a simulated pre-diabetogenic state, we exposed primary cultured fibroblasts from iPD patients and controls to standard (5 mM) and high (25 mM) glucose concentrations to further characterize metabolic and mitochondrial resilience. iPD fibroblasts showed increased organic and amino acid levels related to mitochondrial metabolism with respect to controls, and these differences were enhanced in high glucose conditions (citric, suberic, and sebacic acids levels increased, as well as alanine, glutamate, aspartate, arginine, and ornithine amino acids; p-values between 0.001 and 0.05). The accumulation of metabolites in iPD fibroblasts was associated with (and probably due to) the concomitant mitochondrial dysfunction observed at enzymatic, oxidative, respiratory, and morphologic level. Metabolic and mitochondrial plasticity of controls was not observed in iPD fibroblasts, which were unable to adapt to different glucose conditions. Impaired metabolism and mitochondrial activity in iPD may limit energy supply for cell survival. Moreover, reduced capacity to adapt to disrupted glucose balance characteristic of T2DM may underlay the co-morbidity between both diseases. Conclusions: Fibroblasts from iPD patients showed mitochondrial impairment, resulting in the accumulation of organic and amino acids related to mitochondrial metabolism, especially when exposed to high glucose. Mitochondrial and metabolic defects down warding cell plasticity to adapt to changing glucose bioavailability may explain the comorbidity between iPD and T2DM. ; This work was supported by funds from the Integrated Projects of Excellence PIE14/00061 and the Fondo de Investigaciones Sanitarias of the Instituto de Salud Carlos III (ISCIII) (grant numbers PI1800498 and PI1800451), the Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), all initiatives of ISCIII and FEDER ('Una manera de hacer Europa'), as well as Fundació Privada Cellex and Suports a Grups de Recerca (grant code 2017 SGR 893) and CERCA programs from the Generalitat de Catalunya. Maria de Maeztu Unit of Excellence funded our institution (Institute of Neurosciences, University of Barcelona) as consolidated excellence centre (MDM-2017-0729, Ministry of Science, Innovation and Universities). Two grants from the Spanish government allowed facility maintenance (SAF2017-85877-R from CGR and both SAF2015-69944-R and PID2019-111669RB-I00 from JCFC) ; Peer reviewed
