Dissolution test for risk assessment of nanoparticles: a pilot study

Worldwide efforts are currently trying to produce effective risk assessment models for orally ingested nanoparticles. These tests should provide quantitative information on the bioaccessibility and bioavailability of products of biotransformation, such as dissolved ionic species and/or aggregates. In vitro dissolution tests might be useful for nanoparticle risk assessment, because of their potential to quantitatively monitor the changes of specific properties (e.g., dissolution, agglomeration, etc.), which are critical factors linked to bioaccessibility/bioavailability. Unfortunately, the technological advancement of such tools is currently hampered by the complexity and evolving nature of nanoparticle properties that are strongly influenced by the environment and are often difficult to trace in a standardized manner. Hence, the test's success depends on its ability to quantify such properties using standardized experimental conditions to mimic reality as closely as possible. Here we applied an in vitro dissolution test to quantify the dissolution of silver nanoparticles under dynamic conditions, which likely occur in human digestion, providing a clear description of the bioaccessible ionic species (free and matrix bound ions or soluble silver organic or inorganic complexes) occurring during the different digestion phases. We demonstrated the test feasibility using a multi-technique approach and following pre-standardized operational procedures to allow for a comprehensive description of the process as a whole. Moreover, this can favour data reliability for benchmarking. Finally, we showed how the estimated values of the bioaccessible ionic species relate to absorption and excretion parameters, as measured in vivo. The outcomes presented in this work highlight the potential regulatory role of the dissolution test for orally ingested nanoparticles and, although preliminary, experimentally demonstrate the regulatory oriented "read-across" principle

A novel method using nuclear magnetic resonance for plasma protein binding assessment in drug discovery programs.

A new methodology based on Nuclear Magnetic Resonance (NMR) was developed to determine plasma protein binding (PPB) of drug candidates in drug discovery programs. A strong correlation was found between the attenuation of NMR signals of diverse drugs in the presence of different plasma concentrations and their fraction bound (f b ) reported in the literature. Based on these results, a protocol for a rapid calculation of f b of small molecules was established. The advantage of using plasma instead of purified recombinant proteins and the possibility of pool analysis to increase throughput were also evaluated. This novel methodology proved to be very versatile, cost-effective, fast and suitable for automation. As a plus, it contemporarily provides a quality check and solubility of the compound

Mycoplasma pulmonis e/ou Mycoplasma arthritidis em animais de laboratório (ratos e camundongos) de diferentes biotérios

Ratos e camundongos de três biotérios com e um sem barreiras microbianas foram bacteriologicamente estudados quanto à presença de micoplasma, através da perfusão de pulmão com lavado traqueobrônquico e lavado de ouvido. Caracterizou-se a presença destas bactérias pela formação de colônias em "ovo frito", coloração de Dienes, resistência à digitonina, catabolismo da glicose, hidrólise da arginina, redução do tetrazólio e produção de filme e manchas. A identificação das cepas isoladas foi através da inibição de crescimento. No biotério com barreiras microbianas, os micoplasmas não foram detectados. Entretanto, isolou-se Mycoplasma pulmonis e Mycoplasma arthritidis em biotérios sem barreiras. Nas instalações sem barreiras microbianas com amostragem representativa, detectou-se M. pulmonis em 20% dos camundongos Swiss, 14,28% na linhagem C57B1/6J e em 83,78% na amostragem dos ratos. Encontrou-se M. arthritidis em 5,4% dos ratos, através da lavagem de ouvido. Ambas as espécies estavam presentes em 2,7% dos ratos. Os anti-soros utilizados não identificaram uma cepa isolada de hamster. M. pulmonis foi identificado em ratos de um grupo de animais procedentes de outros 2 biotérios. A taxa de infecção por micoplasma não pôde ser estabelecida porque os ratos e camundongos foram especialmente selecionados para a pesquisa de micoplasma devido a sua origem a aspectos clínicos. Os autores sugerem que a pesquisa de micoplasma em animais de laboratório seja freqüente, com amostragem representativa e com a identificação destes microrganismos para o aprimoramento de seu controle.Rats and mice from different animal house facilities without microbial barriers and one from barrier sustained facilities were checked for mycoplasma presence by lung perfusion with tracheobronquial lavage and ear flushing. Mycoplasmas were characterized by "fried egg" colonies, Dienes stain and digitonine resistance. Glucose catabolism, arginine hydrolysis, tetrazoliun reduction and film/ spots production was applied as screening differential assays. Identification was performed by growth inhibition test. In the barrier sustained colonies, mycoplasmas were not detected, but from a conventional animal house, M. pulmonis was found in the follow order: 20.0% in Swiss mice, 14.28% in C57BL/6J colonies and 83.79% in Wistar rats. M. arthritidis was isolated only from rats by ear flushing in order of 5.4%. Both species were observed in one rat and one unidentified strain of mycolplasma was isolated from hamsters. M. pulmonis was obtained from rats but not from mice proceeded from other two conventional animal houses. Mycoplasma infection rate could not be established in these facilities because rats and mice were specially selected, as usually is to search mycoplasmas, based on their origin and symptoms. The authors suggest that mycoplasma investigation nust be permanent in any animal house rearing rodents. Mycoplasma infection rate must be established with a representative sampling not including only sick animals

Keratin–cinnamon essential oil biocomposite fibrous patches for skin burn care

Keratin based electrospun fibres containing cinnamon essential oil are highly antioxidant and antibacterial, and promote reduced tissue inflammation after skin burns

The mood stabilizing properties of AF3581, a novel potent GSK-3β inhibitor

Glycogen synthase kinase 3β (GSK-3β) is a serine/threonine protein kinase mediating phosphorylation on serine and threonine amino acid residues of several target molecules. The enzyme is involved in the regulation of many cellular processes and aberrant activity of GSK-3β has been linked to several disease conditions. There is now large evidence on the role of GSK-3β in the pathophysiology of mood disturbances with special regard to bipolar disorders. In the present study we further investigated the role of GSK-3β in bipolar disorders by studying AF3581, the prototype of a novel class of ATP-competitive GSK-3β inhibitors having the common N-[(1- alkylpiperidin-4-yl) methyl]-1H-indazole-3-carboxamide scaffold. Based on previous studies, AF3581 inhibits GSK-3β in the nanomolar range on purified human enzyme and highly selective with respect to other kinases. Current study demonstrates that the compound has efficacy both in the chronic mild stress paradigm of depression (mimicking the down phase of bipolar disorder) and on mice aggressiveness in the resident intruder model (mimicking the up phase). These findings underline the importance of aberrant GSK-3β activity in the development/ maintenance of mood oscillation in this peculiar pathological condition. Moreover, the present work also suggests a therapeutic potential for selective GSK-3 β inhibitors in the management of bipolar disorders patients. Glycogen synthase kinase 3β (GSK-3β) is a serine/threonine protein kinase mediating phosphorylation on serine and threonine amino acid residues of several target molecules. The enzyme is involved in the regulation of many cellular processes and aberrant activity of GSK-3β has been linked to several disease conditions. There is now large evidence on the role of GSK-3β in the pathophysiology of mood disturbances with special regard to bipolar disorders. In the present study we further investigated the role of GSK-3β in bipolar disorders by studying AF3581, the prototype of a novel class of ATP-competitive GSK-3β inhibitors having the common N-[(1- alkylpiperidin-4-yl) methyl]-1H-indazole-3-carboxamide scaffold. Based on previous studies, AF3581 inhibits GSK-3β in the nanomolar range on purified human enzyme and highly selective with respect to other kinases. Current study demonstrates that the compound has efficacy both in the chronic mild stress paradigm of depression (mimicking the down phase of bipolar disorder) and on mice aggressiveness in the resident intruder model (mimicking the up phase). These findings underline the importance of aberrant GSK-3β activity in the development/ maintenance of mood oscillation in this peculiar pathological condition. Moreover, the present work also suggests a therapeutic potential for selective GSK-3 β inhibitors in the management of bipolar disorders patients. Glycogen synthase kinase 3β (GSK-3β) is a serine/threonine protein kinase mediating phosphorylation on serine and threonine amino acid residues of several target molecules. The enzyme is involved in the regulation of many cellular processes and aberrant activity of GSK-3β has been linked to several disease conditions. There is now large evidence on the role of GSK-3β in the pathophysiology of mood disturbances with special regard to bipolar disorders. In the present study we further investigated the role of GSK-3β in bipolar disorders by studying AF3581, the prototype of a novel class of ATP-competitive GSK-3β inhibitors having the common N-[(1- alkylpiperidin-4-yl) methyl]-1H-indazole-3-carboxamide scaffold. Based on previous studies, AF3581 inhibits GSK-3β in the nanomolar range on purified human enzymeand highly selective with respect to other kinases. Current study demonstrates that the compound has efficacy both in the chronic mild stress paradigm of depression (mimicking the down phase of bipolar disorder) and on mice aggressiveness in the resident intruder model (mimicking the up phase). These findings underline the importance of aberrant GSK-3β activity in the development/ maintenance of mood oscillation in this peculiar pathological condition. Moreover, the present work also suggests a therapeutic potential for selective GSK-3 β inhibitors in the management of bipolar disorders patients. Glycogen synthase kinase 3β (GSK-3β) is a serine/threonine protein kinase mediating phosphorylation on serine and threonine amino acid residues of several target molecules. The enzyme is involved in the regulation of many cellular processes and aberrant activity of GSK-3β has been linked to several disease conditions. There is now large evidence on the role of GSK-3β in the pathophysiology of mood disturbances with special regard to bipolar disorders. In the present study we further investigated the role of GSK-3β in bipolar disorders by studying AF3581, the prototype of a novel class of ATP-competitive GSK-3β inhibitors having the common N-[(1- alkylpiperidin-4-yl) methyl]-1H-indazole-3-carboxamide scaffold. Based on previous studies, AF3581 inhibits GSK-3β in the nanomolar range on purified human enzyme and highly selective with respect to other kinases. Current study demonstrates that the compound has efficacy both in the chronic mild stress paradigm of depression (mimicking the down phase of bipolar disorder) and on mice aggressiveness in the resident intruder model (mimicking the up phase). These findings underline the importance of aberrant GSK-3β activity in the development/ maintenance of mood oscillation in this peculiar pathological condition. Moreover, the present work also suggests a therapeutic potential for selective GSK-3 β inhibitors in the management of bipolar disorders patients. Glycogen synthase kinase 3β (GSK-3β) is a serine/threonine protein kinase mediating phosphorylation on serine and threonine amino acid residues of several target molecules. The enzyme is involved in the regulation of many cellular processes and aberrant activity of GSK-3β has been linked to several disease conditions. There is now large evidence on the role of GSK-3β in the pathophysiology of mood disturbances with special regard to bipolar disorders. In the present study we further investigated the role of GSK-3β in bipolar disorders by studying AF3581, the prototype of a novel class of ATP-competitive GSK-3β inhibitors having the common N-[(1- alkylpiperidin-4-yl) methyl]-1H-indazole-3-carboxamide scaffold. Based on previous studies, AF3581 inhibits GSK-3β in the nanomolar range on purified human enzyme and highly selective with respect to other kinases. Current study demonstrates that the compound has efficacy both in the chronic mild stress paradigm of depression (mimicking the down phase of bipolar disorder) and on mice aggressiveness in the resident intruder model (mimicking the up phase). These findings underline the importance of aberrant GSK-3β activity in the development/ maintenance of mood oscillation in this peculiar pathological condition. Moreover, the present work also suggests a therapeutic potential for selective GSK-3 β inhibitors in the management of bipolar disorders patients. Glycogen synthase kinase 3β (GSK-3β) is a serine/threonine protein kinase mediating phosphorylation on serine and threonine amino acid residues of several target molecules. The enzyme is involved in the regulation of many cellular processes and aberrant activity of GSK-3β has been linked to several disease conditions. There is now large evidence on the role of GSK-3β in the pathophysiology of mood disturbances with special regard to bipolar disorders. In the present study we further investigated the role of GSK-3β in bipolar disorders by studying AF3581, the prototype of a novel class of ATP-competitive GSK-3β inhibitors having the common N-[(1- alkylpiperidin-4-yl) methyl]-1H-indazole-3-carboxamide scaffold. Based on previous studies, AF3581 inhibits GSK-3β in the nanomolar range on purified human enzyme and highly selective with respect to other kinases. Current study demonstrates that the compound has efficacy both in the chronic mild stress paradigm of depression (mimicking the down phase of bipolar disorder) and on mice aggressiveness in the resident intruder model (mimicking the up phase). These findings underline the importance of aberrant GSK-3β activity in the development/ maintenance of mood oscillation in this peculiar pathological condition. Moreover, the present work also suggests a therapeutic potential for selective GSK-3 β inhibitors in the management of bipolar disorders patients. Glycogen synthase kinase 3β (GSK-3β) is a serine/threonine protein kinase mediating phosphorylation on serine and threonine amino acid residues of several target molecules. The enzyme is involved in the regulation of many cellular processes and aberrant activity of GSK-3β has been linked to several disease conditions. There is now large evidence on the role of GSK-3β in the pathophysiology of mood disturbances with special regard to bipolar disorders. In the present study we further investigated the role of GSK-3β in bipolar disorders by studying AF3581, the prototype of a novel class of ATP-competitive GSK-3β inhibitors having the common N-[(1- alkylpiperidin-4-yl) methyl]-1H-indazole-3-carboxamide scaffold. Based on previous studies, AF3581 inhibits GSK-3β in the nanomolar range on purified human enzyme and highly selective with respect to other kinases. Current study demonstrates that the compound has efficacy both in the chronic mild stress paradigm of depression (mimicking the down phase of bipolar disorder) and on mice aggressiveness in the resident intruder model (mimicking the up phase). These findings underline the importance of aberrant GSK-3β activity in the development/ maintenance of mood oscillation in this peculiar pathological condition. Moreover, the present work also suggests a therapeutic potential for selective GSK-3 β inhibitors in the management of bipolar disorders patients

Alginate–lavender nanofibers with antibacterial and anti-inflammatory activity to effectively promote burn healing

One of the current challenges in wound care is the development of multifunctional dressings that can both protect the wound from external agents and promote the regeneration of the new tissue. Here, we show the combined use of two naturally derived compounds, sodium alginate and lavender essential oil, for the production of bioactive nanofibrous dressings by electrospinning, and their efficacy for the treatment of skin burns induced by midrange ultraviolet radiation (UVB). We demonstrate that the engineered dressings reduce the risk of microbial infection of the burn, since they stop the growth of Staphylococcus aureus. Furthermore, they are able to control and reduce the inflammatory response that is induced in human foreskin fibroblasts by lipopolysaccharides, and in rodents by UVB exposure. In particular, we report a remarkable reduction of pro-inflammatory cytokines when fibroblasts or animals are treated with the alginate-based nanofibers. The down-regulation of cytokines production and the absence of erythema on the skin of the treated animals confirm that the here described dressings are promising as advanced biomedical devices for burn management

Label-Free Intracellular Multi-Specificity in Yeast Cells by Phase-Contrast Tomographic Flow Cytometry

: In-flow phase-contrast tomography provides a 3D refractive index of label-free cells in cytometry systems. Its major limitation, as with any quantitative phase imaging approach, is the lack of specificity compared to fluorescence microscopy, thus restraining its huge potentialities in single-cell analysis and diagnostics. Remarkable results in introducing specificity are obtained through artificial intelligence (AI), but only for adherent cells. However, accessing the 3D fluorescence ground truth and obtaining accurate voxel-level co-registration of image pairs for AI training is not viable for high-throughput cytometry. The recent statistical inference approach is a significant step forward for label-free specificity but remains limited to cells' nuclei. Here, a generalized computational strategy based on a self-consistent statistical inference to achieve intracellular multi-specificity is shown. Various subcellular compartments (i.e., nuclei, cytoplasmic vacuoles, the peri-vacuolar membrane area, cytoplasm, vacuole-nucleus contact site) can be identified and characterized quantitatively at different phases of the cells life cycle by using yeast cells as a biological model. Moreover, for the first time, virtual reality is introduced for handling the information content of multi-specificity in single cells. Full fruition is proofed for exploring and interacting with 3D quantitative biophysical parameters of the identified compartments on demand, thus opening the route to a metaverse for 3D microscopy