Publications
36 results found
Mohammed AA, Yao K, Ragaisyte I, et al., 2024, Stable and homogeneous SPION-infused Photo-Resins for 3D-printing magnetic hydrogels, Applied Materials Today, Vol: 37
3D printing of magnetic stimuli hydrogels has shown promise in low-resolution extrusion printing but integrating superparamagnetic iron oxide nanoparticles (SPION) into water-based photo-resins has posed challenges. Rapid agglomeration and sedimentation of SPION in photo-resins require continuous mixing during printing, leading to uneven nanoparticle (NP) distribution and inconsistent magnetic actuation. Here, we optimise the use of citric acid (CA) and l-sodium ascorbate (LA) as capping agents on the SPION's surface, before trialling them with photo-resins. Ultimately, we present a two-step approach to overcome these limitations, enabling high-resolution SLA-based 3D printing of hydrogels. By employing CA in both SPION and photo-resin preparation, we achieve a highly stable mixture that requires no agitation during printing, resulting in magnetically responsive hydrogels. This methodology can be applied to various photo-resin formulations, ensuring uniform NP distribution and enabling the 3D printing of stimuli-responsive materials for applications in soft robotics, aquatic micro-swimmers, and soft actuators. The breakthrough in stable and homogenous SPION-infused photo-resins has broad implications for tissue engineering, drug delivery, and regenerative medicine, offering novel biocompatible materials with resistance to stress and deformation. This approach can be extended to other NP with poor dispersion in hydrogels, paving the way for advanced functional materials in diverse applications.
Kaasalainen M, Zhang R, Vashisth P, et al., 2024, Lithiated porous silicon nanowires stimulate periodontal regeneration, Nature Communications, Vol: 15, ISSN: 2041-1723
Periodontal disease is a significant burden for oral health, causing progressive and irreversible damage to the support structure of the tooth. This complex structure, the periodontium, is composed of interconnected soft and mineralised tissues, posing a challenge for regenerative approaches. Materials combining silicon and lithium are widely studied in periodontal regeneration, as they stimulate bone repair via silicic acid release while providing regenerative stimuli through lithium activation of the Wnt/β-catenin pathway. Yet, existing materials for combined lithium and silicon release have limited control over ion release amounts and kinetics. Porous silicon can provide controlled silicic acid release, inducing osteogenesis to support bone regeneration. Prelithiation, a strategy developed for battery technology, can introduce large, controllable amounts of lithium within porous silicon, but yields a highly reactive material, unsuitable for biomedicine. This work debuts a strategy to lithiate porous silicon nanowires (LipSiNs) which generates a biocompatible and bioresorbable material. LipSiNs incorporate lithium to between 1% and 40% of silicon content, releasing lithium and silicic acid in a tailorable fashion from days to weeks. LipSiNs combine osteogenic, cementogenic and Wnt/β-catenin stimuli to regenerate bone, cementum and periodontal ligament fibres in a murine periodontal defect.
Mohammed AA, Li S, Sang T, et al., 2023, Nanocomposite hydrogels with polymer grafted silica nanoparticles, using glucose oxidase, Gels, Vol: 9, Pages: 1-15, ISSN: 2310-2861
Nanocomposite hydrogels offer remarkable potential for applications in bone tissue engineering. They are synthesized through the chemical or physical crosslinking of polymers and nanomaterials, allowing for the enhancement of their behaviour by modifying the properties and compositions of the nanomaterials involved. However, their mechanical properties require further enhancement to meet the demands of bone tissue engineering. Here, we present an approach to improve the mechanical properties of nanocomposite hydrogels by incorporating polymer grafted silica nanoparticles into a double network inspired hydrogel (gSNP Gels). The gSNP Gels were synthesised via a graft polymerization process using a redox initiator. gSNP Gels were formed by grafting 2-acrylamido-2-methylpropanesulfonic acid (AMPS) as the first network gel followed by a sequential second network acrylamide (AAm) onto amine functionalized silica nanoparticles (ASNPs). We utilized glucose oxidase (GOx) to create an oxygen-free atmosphere during polymerization, resulting in higher polymer conversion compared to argon degassing. The gSNP Gels showed excellent compressive strengths of 13.9 ± 5.5 MPa, a strain of 69.6 ± 6.4%, and a water content of 63.4% ± 1.8. The synthesis technique demonstrates a promising approach to enhance the mechanical properties of hydrogels, which can have significant implications for bone tissue engineering and other soft tissue applications.
Mohammed AA, Miao J, Ragaisyte I, et al., 2023, 3D printed superparamagnetic stimuli-responsive starfish-shaped hydrogels, Heliyon, Vol: 9, Pages: 1-13, ISSN: 2405-8440
Magnetic-stimuli responsive hydrogels are quickly becoming a promising class of materials across numerous fields, including biomedical devices, soft robotic actuators, and wearable electronics. Hydrogels are commonly fabricated by conventional methods that limit the potential for complex architectures normally required for rapidly changing custom configurations. Rapid prototyping using 3D printing provides a solution for this. Previous work has shown successful extrusion 3D printing of magnetic hydrogels; however, extrusion-based printing is limited by nozzle resolution and ink viscosity. VAT photopolymerization offers a higher control over resolution and build-architecture. Liquid photo-resins with magnetic nanocomposites normally suffer from nanoparticle agglomeration due to local magnetic fields. In this work, we develop an optimised method for homogenously infusing up to 2 wt % superparamagnetic iron oxide nanoparticles (SPIONs) with a 10 nm diameter into a photo-resin composed of water, acrylamide and PEGDA, with improved nanoparticle homogeneity and reduced agglomeration during printing. The 3D printed starfish hydrogels exhibited high mechanical stability and robust mechanical properties with a maximum Youngs modulus of 1.8 MPa and limited shape deformation of 10% when swollen. Each individual arm of the starfish could be magnetically actuated when a remote magnetic field is applied. The starfish could grab onto a magnet with all arms when a central magnetic field was applied. Ultimately, these hydrogels retained their shape post-printing and returned to their original formation once the magnetic field had been removed. These hydrogels can be used across a wide range of applications, including soft robotics and magnetically stimulated actuators.
Morfill C, Pankratova S, Machado P, et al., 2023, Addition to "Nanostars carrying multifunctional neurotrophic dendrimers protect neurons in preclinical in vitro models of neurodegenerative disorders"., ACS Applied Materials and Interfaces, Vol: 15, Pages: 13824-13824, ISSN: 1944-8244
In the original version of this article (p. 47457), some acknowledgments were not included. In the revised Acknowledgments section provided below, we additionally provide The REC reference for the ethical approval of the human astrocyte isolation, an acknowledgment to Dr. Alize Proust at the Francis Crick Institute for establishing the triple coculture BBB model used in this study, and the reference and the grant number for the source of the human fetal material. This does not affect the results or conclusions of our work.
Mohammed AA, Merrild NG, Li S, et al., 2022, Double-network hydrogels reinforced with covalently bonded silica nanoparticles via 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide chemistry, ACS Omega, Vol: 7, Pages: 43904-43914, ISSN: 2470-1343
Hydrogels have progressed from single-network materials with low mechanical integrity to double-network hydrogels (DNHGs) with tough, tunable properties. In this work, we introduce a nanocomposite structure into the first network of a DNHG. Amine-functionalized silica nanoparticles (ASNPs) were covalently cross-linked by forming amide bonds through the carboxylic groups of polyacrylic acid (PAAc) in the first network. DNHGs with varying sizes of ASNPs (50, 100, and 150 nm) and varying concentrations (2.5, 10, 20, and 40 wt %) were explored and compared to a control without a nanocomposite structure. Compressive strengths improved from 0.10 MPa for the control to a maximum of 1.28 MPa for the PAAc/PAAm DNHGs. All hydrogels experienced increased resistance to strain with a maximum of 74% compared to 45% for the control. SEM images of freeze-dried gels showed that ASNPs were integrated into the gel mesh. Nanoparticle retention was calculated using thermal gravimetric analysis (TGA) with improved retention values for larger ASNPs. New DNHG composites have been formed with improved mechanical properties and a potential use in tissue engineering and biomaterial applications.
Morfill C, Pankratova S, Machado P, et al., 2022, Nanostars Carrying Multifunctional Neurotrophic Dendrimers Protect Neurons in Preclinical In Vitro Models of Neurodegenerative Disorders, ACS APPLIED MATERIALS & INTERFACES, Vol: 14, Pages: 47445-47460, ISSN: 1944-8244
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- Citations: 5
Naruphontjirakul P, Li S, Pinna A, et al., 2022, Interaction of monodispersed strontium containing bioactive glass nanoparticles with macrophages, Biomaterials Advances, Vol: 133, Pages: 1-12, ISSN: 2772-9508
The cellular response of murine primary macrophages to monodisperse strontium containing bioactive glass nanoparticles (SrBGNPs), with diameters of 90 ± 10 nm and a composition (mol%) of 88.8 SiO2–1.8CaO-9.4SrO (9.4% Sr-BGNPs) was investigated for the first time. Macrophage response is critical as applications of bioactive nanoparticles will involve the nanoparticles circulating in the blood stream and macrophages will be the first cells to encounter the particles, as part of inflammatory response mechanisms. Macrophage viability and total DNA measurements were not decreased by particle concentrations of up to 250 μg/mL. The Sr-BGNPs were actively internalised by the macrophages via formation of endosome/lysosome-like vesicles bordered by a membrane inside the cells. The Sr-BGNPs degraded inside the cells, with the Ca and Sr maintained inside the silica network. When RAW264.7 cells were incubated with Sr-BGNPs, the cells were polarised towards the pro-regenerative M2 population rather than the pro-inflammatory M1 population. Sr-BGNPs are potential biocompatible vehicles for therapeutic cation delivery for applications in bone regeneration.
Kumar P, Kalaiarasan G, Porter AE, et al., 2021, An overview of methods of fine and ultrafine particle collection for physicochemical characterisation and toxicity assessments., Science of the Total Environment, Vol: 756, Pages: 1-22, ISSN: 0048-9697
Particulate matter (PM) is a crucial health risk factor for respiratory and cardiovascular diseases. The smaller size fractions, ≤2.5 μm (PM2.5; fine particles) and ≤0.1 μm (PM0.1; ultrafine particles), show the highest bioactivity but acquiring sufficient mass for in vitro and in vivo toxicological studies is challenging. We review the suitability of available instrumentation to collect the PM mass required for these assessments. Five different microenvironments representing the diverse exposure conditions in urban environments are considered in order to establish the typical PM concentrations present. The highest concentrations of PM2.5 and PM0.1 were found near traffic (i.e. roadsides and traffic intersections), followed by indoor environments, parks and behind roadside vegetation. We identify key factors to consider when selecting sampling instrumentation. These include PM concentration on-site (low concentrations increase sampling time), nature of sampling sites (e.g. indoors; noise and space will be an issue), equipment handling and power supply. Physicochemical characterisation requires micro- to milli-gram quantities of PM and it may increase according to the processing methods (e.g. digestion or sonication). Toxicological assessments of PM involve numerous mechanisms (e.g. inflammatory processes and oxidative stress) requiring significant amounts of PM to obtain accurate results. Optimising air sampling techniques are therefore important for the appropriate collection medium/filter which have innate physical properties and the potential to interact with samples. An evaluation of methods and instrumentation used for airborne virus collection concludes that samplers operating cyclone sampling techniques (using centrifugal forces) are effective in collecting airborne viruses. We highlight that predictive modelling can help to identify pollution hotspots in an urban environment for the efficient collection of PM mass. This review provides
Pinna A, Baghbaderani MT, Hernandez VV, et al., 2021, Nanoceria provides antioxidant and osteogenic properties to mesoporous silica nanoparticles for osteoporosis treatment, Acta Biomaterialia, Vol: 122, Pages: 365-376, ISSN: 1742-7061
Osteoporosis, a chronic metabolic bone disease, is the most common cause of fractures. Drugs for treating osteoporosis generally inhibit osteoclast (OC) activity, but are rarely aimed at encouraging new bone growth and often cause severe systemic side effects. Reactive oxygen species (ROS) are one of the key triggers of osteoporosis, by inducing osteoblast (OB) and osteocyte apoptosis and promoting osteoclastogenesis. Here we tested the capability of the ROS-scavenger nanoceria encapsulated within mesoporous silica nanoparticles (Ce@MSNs) to treat osteoporosis using a pre-osteoblast MC3T3-E1 cell monoculture in stressed and normal conditions. Ce@MSNs (diameter of 80 ± 10 nm) were synthesised following a scalable two-step process involving sol-gel and wet impregnation methods. The Ce@MSNs at concentration of 100 μg mL−1 induced a significant reduction in oxidative stress produced by t-butyl hydroperoxide and did not alter cell viability significantly. Confocal microscopy showed that MSNs and Ce@MsNs were internalised into the cytoplasm of the pre-osteoblasts after 24 h but were not in the nucleus, avoiding any DNA and RNA modifications. Ce@MSNs provoked mineralisation of the pre-osteoablasts without osteogenic supplements, which did not occur when the cells were exposed to MSN without nanoceria. In a co-culture system of MC3T3-E1 and RAW264.7 macrophages, the Ce@MSNs exhibited antioxidant capability and stimulated cell proliferation and osteogenic responses without adding osteogenic supplements to the culture. The work brings forward an effective platform based for facile synthesis of Ce@MSNs to interact with both OBs and OCs for treatment of osteoporosis.
Avitabile E, Senes N, D'Avino C, et al., 2020, The potential antimalarial efficacy of hemocompatible silver nanoparticles fromArtemisiaspecies againstP.falciparumparasite, PLoS One, Vol: 15, Pages: 1-17, ISSN: 1932-6203
Malaria represents one of the most common infectious diseases which becoming an impellent public health problem worldwide. Antimalarial classical medications include quinine-based drugs, like chloroquine, and artesunate, a derivative of artemisinin, a molecule found in the plant Artemisia annua. Such therapeutics are very effective but show heavy side effects like drug resistance. In this study, “green” silver nanoparticles (AgNPs) have been prepared from two Artemisia species (A. abrotanum and A. arborescens), traditionally used in folk medicine as a remedy for different conditions, and their potential antimalarial efficacy have been assessed. AgNPs have been characterized by UV-Vis, dynamic light scattering and zeta potential, FTIR, XRD, TEM and EDX. The structural characterization has demonstrated the spheroidal shape of nanoparticles and dimensions under 50 nm, useful for biomedical studies. Zeta potential analysis have shown the stability and dispersion of green AgNPs in aqueous medium without aggregation. AgNPs hemocompatibility and antimalarial activity have been studied in Plasmodium falciparum cultures in in vitro experiments. The antiplasmodial effect has been assessed using increasing doses of AgNPs (0.6 to 7.5 μg/mL) on parasitized red blood cells (pRBCs). Obtained data showed that the hemocompatibility of AgNPs is related to their synthetic route and depends on the administered dose. A. abrotanum-AgNPs (1) have shown the lowest percentage of hemolytic activity on pRBCs, underlining their hemocompatibility. These results are in accordance with the lower levels of parasitemia observed after A. abrotanum-AgNPs (1) treatment respect to A. arborescens-AgNPs (2), and AgNPs (3) derived from a classical chemical synthesis. Moreover, after 24 and 48 hours of A. abrotanum-AgNPs (1) treatment, the parasite growth was locked in the ring stage, evidencing the effect of these nanoparticles to hinder the maturation of P. falciparum. The anti-malarial ac
Pinna A, Cali E, Kerherve G, et al., 2020, Fulleropyrrolidine-functionalized ceria nanoparticles as a tethered dual nanosystem with improved antioxidant properties, Nanoscale Advances, Vol: 2, Pages: 2387-2396, ISSN: 2516-0230
Dual-tethered nanosystems which combine different properties at the nano scale represent a new fascinating frontier of research. In the present work, we present an example of a dual nanosystem designed to enhance the radical scavenging performances. Fulleropyrrolidine has been bonded to cerium oxide nanoparticles (nanoceria) to form a dual tethered system. Fulleropyrrolidine, bearing a silyl-alkoxide group, has been chemically bonded to the nanoceria surface, providing unprecedented antioxidant activity. This effect has been evaluated using an L929 mouse fibroblast cell line exposed to UV light. The fulleropyrrolidine molecules tethered to nanoceria enhance the radical scavenging properties of the oxide. At the same time, fulleropyrrolidine mitigates the potential toxicity of nanoceria at high doses. On the other hand, cerium oxide nanoparticles provide a strong hydrophilicity to the dual nanosystem, ensuring the administration in a cellular environment and preventing macroscopic aggregation of fulleropyrrolidine. The rational assembly of two different components in one nanosystem appears as a promising route for the development of “smarter” medical and cosmetic devices.
Mohammed AA, Pinna A, Li S, et al., 2020, Auto-catalytic redox polymerisation using nanoceria and glucose oxidase for double network hydrogels, Journal of Materials Chemistry B, Vol: 8, Pages: 2834-2844, ISSN: 2050-750X
A novel auto-catalytic reaction, a combination of naturally occurring enzyme glucose oxidase (GOx) and amine-functionalised cerium oxide nanoparticles (nanoceria), was employed for open vessel free radical polymerisation of double network hydrogels (DNHGs). The nanoceria also incorporated into the gels to enhance mechanical strength. GOx reduces atmospheric O2 to H2O2, causing a cyclic change of cerium ion states, resulting in propagating free radicals in the carbon group in the amino functionalised nanoceria surface. We synthesised novel nanocomposite DNHGs by grafting polymers onto amine-functionalised nanoceria (ANC), with poly(2-acrylamido-2-methylpropanesulfonic acid), PAMPS, and polyacrylamide (PAAm) in the first and second networks respectively. The graft polymerisation was initiated using the alternating cerium states on the ANC. GOx held two major roles within the reaction: to provide an oxygen free system, without any other form of degassing, and to provide cyclical cerium ion states between Ce4+ and Ce3+, creating new free radicals for polymerisation. Polymer conversion using ANC as the sole initiator in the presence of GOx resulted in 83% conversion for PAMPS and 64% PAAm. Polymers degassed only with argon resulted in less than 55% conversion for both PAAm and PAMPS, proving that the addition of GOx enhanced the reaction. The new gels (1.76 MPa) showed an order of magnitude improvement in mechanical properties compared to DNHG made without ANC/GOx (0.10 MPa).
Ravanbakhsh M, Labbaf S, Karimzadeh F, et al., 2019, Mesoporous bioactive glasses for the combined application of osteosarcoma treatment and bone regeneration, Materials Science and Engineering C: Materials for Biological Applications, Vol: 104, Pages: 1-10, ISSN: 0928-4931
In this study, mesoporous bioactive glass (MBG) sub-micro particles were prepared through sol-gel synthesis and possessed a uniform and spherical structure with particle size of 302 ± 43 nm, a pore size of 4 nm and a high surface area of 354 m2 g−1. Alendronate (AL) is often used for the treatment of bone associated diseases, in particular osteosarcoma. However, due to the low bioavailability and high toxicity at increased doses, local and sustained release would be an ideal approach to AL delivery. Here, MBGs and aminated MBGs (AMBG) were applied as carriers for AL loading. High encapsulation efficiency of 75% and 85% and loading efficiency of 60% and 63%, for MBG and AMBG, respectively, was achieved. The release profile of AL from AMBG showed a better sustained and controlled release mechanism compared to MBG. In vitro results demonstrated the non-cytotoxic nature of both MBG and AMBG following exposure to MG63 osteoblast like cell line. AL release from MBG and AMBG, even at lower concentration, provoked decreased MG63 proliferation. The osteogenic potential of MBG and AMBG following exposure to dental pulp stem cells was evaluated using alizarin red assay.
Pinna A, Ricco R, Migheli R, et al., 2018, A MOF-based carrier for in situ dopamine delivery, RSC Advances: an international journal to further the chemical sciences, Vol: 8, Pages: 25664-25672, ISSN: 2046-2069
MIL-88A (Fe) MOF crystals were nucleated and grown around a polymer core containing superparamagnetic nanoparticles to assemble a new class of biocompatible particles for magnetophoretic drug delivery of dopamine. The carrier enabled efficient targeted release, dopamine protection from oxidative damage, long-term delivery and improved drug delivery cost-efficiency. After loading, dopamine was stable within the carrier and did not undergo oxidation. Drug release monitoring via spectrofluorimetry revealed a shorter burst effect and higher release efficiency than silica based carriers. The in vitro cytotoxicity at different MOF concentrations and sizes was assessed using PC12 cells as the neuronal cell model. The drug was directly uptaken into the PC12 cells avoiding possible side effects due to oxidation occurring in the extracellular environment.
Falchi L, Galleri G, Dore GM, et al., 2018, Effect of exposure to CeO2 nanoparticles on ram spermatozoa during storage at 4 degrees C for 96 hours, Reproductive Biology and Endocrinology, Vol: 16, ISSN: 1477-7827
BackgroundCerium oxide nanoparticles (CeO2 NPs) are able to store and release oxygen, conferring them scavenger activity against oxidative stress. However, their effects in reproductive systems are not yet well understood. The aim of the study was to investigate the effects of exposure of refrigerated ram semen to CeO2 NPs for 96 h on the main structural and kinematic parameters of spermatozoa.MethodsThe ejaculates of 5 Sarda rams were collected, pooled and diluted in a soybean lecithin extender. Samples were exposed to increasing doses of CeO2 NPs (0, 44 and 220 μg/mL) and stored at 4 °C for 96 h. Analyses of kinematic parameters (computer assisted sperm analysis, CASA), integrity of membranes (PI/PSA staining), ROS production (H2DCFDA staining) and DNA damage (sperm chromatin structure assay with acridine orange, SCSA) were performed every 24 h (0, 24, 48, 72 and 96 h of incubation). The experiment was carried out in 6 replicates. Data were analysed by repeated measures ANOVA with Bonferroni’s as post hoc test. When the assumption of normality was not met (ROS), non-parametric Kruskal-Wallis rank test was carried out.ResultsExposure of ram spermatozoa to increasing doses of CeO2 NPs had a beneficial effect on the main motility parameters from 48 h of incubation onward. Velocity of sperm cells was enhanced in the groups exposed to CeO2 NPs compared to the control. Incubation with NPs had beneficial effects on the integrity of plasma membranes of spermatozoa, with higher percentage of damaged cells in the control group compared to the exposed ones. Production of ROS was not affected by exposure to NPs and its levels rose at 96 h of incubation. The integrity of DNA remained stable throughout the 96 h of storage regardless of co-incubation with NPs.ConclusionsWe reported beneficial effects of CeO2 NPs on kinematic and morphologic parameters of ram semen, such as motility and membrane integrity following 96 h of exposure. Furthermore, we also proved no gen
Nommeots-Nomm A, Labbaf S, Devlin A, et al., 2017, Highly degradable porous melt-derived bioactive glass foam scaffolds for bone regeneration, Acta Biomaterialia, Vol: 57, Pages: 449-461, ISSN: 1878-7568
A challenge in using bioactive melt-derived glass in bone regeneration is to produce scaffolds with interconnected pores while maintaining the amorphous nature of the glass and its associated bioactivity. Here we introduce a method for creating porous melt-derived bioactive glass foam scaffolds with low silica content and report in vitro and preliminary in vivo data. The gel-cast foaming process was adapted, employing temperature controlled gelation of gelatin, rather than the in situ acrylic polymerisation used previously. To form a 3D construct from melt derived glasses, particles must be fused via thermal processing, termed sintering. The original Bioglass® 45S5 composition crystallises upon sintering, altering its bioactivity, due to the temperature difference between the glass transition temperature and the crystallisation onset being small. Here, we optimised and compared scaffolds from three glass compositions, ICIE16, PSrBG and 13–93, which were selected due to their widened sintering windows. Amorphous scaffolds with modal pore interconnect diameters between 100–150 µm and porosities of 75% had compressive strengths of 3.4 ± 0.3 MPa, 8.4 ± 0.8 MPa and 15.3 ± 1.8 MPa, for ICIE16, PSrBG and 13–93 respectively. These porosities and compressive strength values are within the range of cancellous bone, and greater than previously reported foamed scaffolds. Dental pulp stem cells attached to the scaffold surfaces during in vitro culture and were viable. In vivo, the scaffolds were found to regenerate bone in a rabbit model according to X-ray micro tomography imaging.
Ariu F, Bogliolo L, Pinna A, et al., 2017, Cerium oxide nanoparticles (CeO<sub>2</sub> NPs) improve the developmental competence of <i>in vitro</i>-matured prepubertal ovine oocytes, REPRODUCTION FERTILITY AND DEVELOPMENT, Vol: 29, Pages: 1046-1056, ISSN: 1031-3613
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- Citations: 15
Malfatti L, Carboni D, Pinna A, et al., 2016, In situ growth of Ag nanoparticles in graphene-TiO2 mesoporous films induced by hard X-ray, Journal of Sol-Gel Science and Technology, Vol: 79, Pages: 295-302, ISSN: 0928-0707
The controlled growth of Ag nanoparticles into graphene–TiO2 mesoporous films has been triggered by hard X-ray exposure provided by a synchrotron storage ring. The kinetic process has been studied by UV–visible spectroscopy as a function of the X-ray dose and compared to the nanoparticle growth induced in a bare mesoporous titania matrix. The graphene layers act as a preferential nucleation sites, allowing a faster nucleation of the nanoparticles. Moreover, the growth of larger nanoparticles is also promoted as a function of the exposure dose. The combined bottom-up and top-down approach to fabricate nanocomposites porous films embedding both graphene and plasmonic nanoparticles is expected to be a fundamental tool for the design of new analytical platforms based on the enhancement of the Raman signals.
Jiang Y, Carboni D, Pinna A, et al., 2016, Hard X-rays for processing hybrid organic-inorganic thick films., Journal of Synchrotron Radiation, Vol: 23, Pages: 267-273, ISSN: 1600-5775
Hard X-rays, deriving from a synchrotron light source, have been used as an effective tool for processing hybrid organic-inorganic films and thick coatings up to several micrometres. These coatings could be directly modified, in terms of composition and properties, by controlled exposure to X-rays. The physico-chemical properties of the coatings, such as hardness, refractive index and fluorescence, can be properly tuned using the interaction of hard X-rays with the sol-gel hybrid films. The changes in the microstructure have been correlated especially with the modification of the optical and the mechanical properties. A relationship between the degradation rate of the organic groups and the rise of fluorescence from the hybrid material has been observed; nanoindentation analysis of the coatings as a function of the X-ray doses has shown a not linear dependence between thickness and film hardness.
Vacca A, Mascia M, Mais L, et al., 2016, Electrodeposition of Zirconium from 1-Butyl-1-Methylpyrrolidinium-Bis(Trifluoromethylsulfonyl)imide: Electrochemical Behavior and Reduction Pathway, MATERIALS AND MANUFACTURING PROCESSES, Vol: 31, Pages: 74-80, ISSN: 1042-6914
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- Citations: 6
Falchi L, Bogliolo L, Galleri G, et al., 2015, Cerium dioxide nanoparticles did not alter the functional and morphologic characteristics of ram sperm during short-term exposure, Theriogenology, Vol: 85, Pages: 1274-1281.e3, ISSN: 0093-691X
The aim of the study was to investigate the interaction and the short-term effects of increasing doses of cerium dioxide nanoparticles (CeO2 NPs) on ram spermatozoa, stored at 4 °C for up to 24 hours, on the main functional and kinematic parameters. Spermatozoa were incubated with 0, 22, 44, and 220 μg/mL of CeO2 NPs at 4 °C and submitted at 0, 2, and 24 hours to the following analyses: (1) intracellular uptake of CeO2 NPs by the spermatozoa; (2) kinematic parameters; (3) acrosome and membrane integrity; (4) integrity of DNA; (5) mitochondrial activity; (6) ROS production. The results indicated that the exposure of spermatozoa to increasing doses of nanoceria was well tolerated. No intracellular uptake of NPs by the cells was observed and both kinematic parameters and status of the membranes were not affected by the incubation with NPs (P > 0.05). Moreover, no influence on the redox status of spermatozoa and on the levels of fragmentation of DNA was reported among groups at any time (P > 0.05). The data collected provide new information about the impact of CeO2 NPs on the male gamete in large animal model and could open future perspectives about their biomedical use in the assisted reproductive techniques.
Pinna A, Malfatti L, Galleri G, et al., 2015, Ceria nanoparticles for the treatment of Parkinson-like diseases induced by chronic manganese intoxication, RSC Advances: an international journal to further the chemical sciences, Vol: 5, Pages: 20432-20439, ISSN: 2046-2069
Ceria nanoparticles with controlled size have been studied as antioxidant agents for the in vitro protection of catecholaminergic cells (PC12) exposed to manganese, which is responsible for an occupational form of Parkinson-like disease. The nanoparticle internalization has been followed by Raman and confocal microscopy while the effect of nanoceria concentration in the cell metabolism has been assessed by MTT and trypan blue assay. With the perspective to develop an innovative combined treatment, nanoceria has been tested either alone or in association with L-DOPA showing a significant effect in reducing the oxidative stress due to manganese chloride. Finally, to study the protective role of nanoceria on the metabolism of catecholamines, the intracellular concentration of dopamine and its metabolites have been monitored by liquid chromatography with electro-chemical detection in control and nanoparticle-exposed cells as a function of the nanoceria dosing. The results show a protective role of nanoceria both on PC12 cells survival and dopamine metabolism, which makes this class of nanoparticles a potential candidate for the treatment of Parkinson-like diseases induced by chronic manganese intoxication.
Malfatti L, Pinna A, Enzo S, et al., 2015, Tuning the phase transition of ZnO thin films through lithography: an integrated bottom-up and top-down processing, JOURNAL OF SYNCHROTRON RADIATION, Vol: 22, Pages: 165-171, ISSN: 0909-0495
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- Citations: 7
Carboni D, Pinna A, Amenitsch H, et al., 2015, Getting order in mesostructured thin films, from pore organization to crystalline walls, the case of 3-glycidoxypropyltrimethoxysilane, PHYSICAL CHEMISTRY CHEMICAL PHYSICS, Vol: 17, Pages: 10679-10686, ISSN: 1463-9076
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- Citations: 8
Falchi L, Bogliolo L, Galleri G, et al., 2015, 266 BIOCOMPATIBILITY OF NANOCERIA IN RAM SPERM DURING 24 HOURS OF INCUBATION, Reproduction, Fertility and Development, Vol: 27, Pages: 222-222, ISSN: 1031-3613
<jats:p>In recent years, there has been increasing interest in nanoparticles, especially those widely present in our environment. Several studies have been performed to evaluate their potential toxic effect and their possible use for biomedical applications. Among others, cerium dioxide nanoparticles (nanoceria, CeO2 ENPs) have been recently investigated for their use in biomedicine, based on their potential antioxidant function, due to the presence of oxygen vacancies and redox transformations (Ce4+/Ce3+) occurring at the surface. However, little is known about the potential toxicity of nanoceria in the reproductive system and on gametes, and no information is available with regard to its biocompatibility and potential toxicity on male gametes. The aim of the present study was to investigate effects of increasing doses of CeO2 ENPs on ram spermatozoa during 24 h storage at 4°C, based on assessment of main kinematic parameters, membranes and DNA integrity, ROS production, mitochondrial activity, and CeO2 intracellular uptake. The ejaculates of 3 rams of proven fertility were pooled and incubated with increasing doses of nanoceria (0, 22, 44, and 220 µg mL–1) up to 24 h at 4°C. The experiment was conducted in 4 replicates. At 0, 2, and 24 h of incubation, the 4 groups were submitted to the following analyses: i) main kinematic parameters (total motility and progressive motility) through CASA (computer-assisted sperm analysis); ii) acrosome and membrane integrity (propidium iodide + Pisum sativum agglutinin staining, PI+PSA); iii) flow cytometry for sperm chromatin structure assay (SCSA, acridine orange staining), mitochondrial activity (Mitotracker Orange), and ROS production (H2DCFDA). Moreover, an aliquot of semen from each group in each time step was fixed and processed for transmission electron microscopy to assess intracellular uptake of CeO2 nanoparticles by spermatozoa. Increasing conce
Innocenzi P, Malfatti L, Lasio B, et al., 2014, Sol-gel chemistry for graphene-silica nanocomposite films, NEW JOURNAL OF CHEMISTRY, Vol: 38, Pages: 3777-3782, ISSN: 1144-0546
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Falcaro P, Trinchi A, Doherty C, et al., 2014, 3D Spatially Controlled Chemical Functionalization on Alumina Membranes, SCIENCE OF ADVANCED MATERIALS, Vol: 6, Pages: 1520-1524, ISSN: 1947-2935
Pinna A, Lasio B, Carboni D, et al., 2014, Engineering the surface of hybrid organic-inorganic films with orthogonal grafting of oxide nanoparticles, JOURNAL OF NANOPARTICLE RESEARCH, Vol: 16, ISSN: 1388-0764
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Carboni D, Marongiu D, Rassu P, et al., 2014, Enhanced Photocatalytic Activity in Low-Temperature Processed Titania Mesoporous Films, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 118, Pages: 12000-12009, ISSN: 1932-7447
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