Dr Alessandra Pinna

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.

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.

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 guidance to prepare and plan efficient sampling campaigns to collect sufficient PM mass for various purposes in a reasonable timeframe.

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 physicochemical 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.

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. •Monodisperse bioactive glass nanoparticles (Sr-BGNPs), diameters of 90 ± 10 nm, containing strontium, did not cause toxicity in macrophages.•Sr-BGNPs were actively internalised by macrophages via formation of endosome/lysosome-like vesicles bordered by a membrane inside the cells.•TEM enabled visualisation of Sr-BGNPs inside macrophages and EDX showed Ca and Sr were maintained inside Sr-BGNPs during degradation.•Internalisation was via mixed mechanisms but was within vesicles and not the cytoplasm, which is beneficial for therapeutic strategies.•RAW264.7 cells exposed to Sr-BGNPs were poloarised towards the pro-regenerative M2 population rather than the pro-inflammatory M1 population.

The present study investigated whether supplementation with different doses of cerium dioxide nanoparticles (CeO NPs) during in vitro maturation (IVM) of prepubertal ovine oocytes influenced their embryonic development in vitro. Cumulus-oocyte complexes derived from the ovaries of slaughtered prepubertal sheep underwent IVM with CeO NPs (0, 44, 88 or 220µg mL ). Matured oocytes were fertilised in vitro and zygotes were cultured for 7 days. The results demonstrated that CeO NPs were internalised in the cumulus cells and not in the oocyte. The treatment with CeO NPs did not affect nuclear maturation or intracellular levels of reactive oxygen species of the oocytes. The percentage of oocytes with regular chromatin configuration and cytoskeleton structures when treated with 44µg mL CeO NPs was similar to oocytes matured in the absence of CeO NPs and significantly higher than those treated with 88 or 220µg mL CeO NPs. The relative quantification of transcripts in the cumulus cells of oocytes matured with 44µg mL CeO NPs showed a statistically lower mRNA abundance of BCL2-associated X protein (BAX), B-cell CLL/lymphoma 2 (BCL2) and superoxide dismutase 1 (SOD1) compared with the 0µg mL CeO2 NPs group. A concentration of 44µg mL CeO NPs significantly increased the blastocyst yield and their total, inner cell mass and trophectoderm cell numbers, compared with the 0 and 220µg mL groups. A low concentration of CeO NPs in the maturation medium enhanced in vitro embryo production of prepubertal ovine oocytes.

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 (R) 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 mu m 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. Statement of Significance This manuscript describes a new method for making scaffolds from bioactive glasses using highly bioactive glass compositions. The glass compositions have lower silica content that those that have been previously made into amorphous scaffolds and they have been designed to have similar network connectivity to that of the original (and commercially used) 45S5 Bioglass. The aim was to match Bioglass' bioactivity. The scaffolds retain the amorphous nature of bioactive glass while having an open pore structure and compressive strength similar to porous bone (the original 45S5 Bioglass crystallises during sintering, which can cause reduced bioactivity or instability). The new scaffolds showed unexpectedly rapid bone regeneration in a rabbit model. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd.

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.

To fully exploit the potential of self-assembly in a single step, we have designed an integrated process to obtain mesoporous graphene nanocomposite films. The synthesis allows incorporating graphene sheets with a small number of defects into highly ordered and transparent mesoporous titania films. The careful design of the porous matrix at the mesoscale ensures the highest diffusivity in the films. These exhibit an enhanced photocatalytic efficiency, while the high order of the mesoporosity is not affected by the insertion of the graphene sheets and is well-preserved after a controlled thermal treatment. In addition, we have proven that the nanocomposite films can be easily processed by deep X-ray lithography to produce functional arrays.

Nanocomposite thin films formed by mesoporous titania layers loaded with ceria nanoparticles have been obtained by combining bottom-up self-assembly synthesis of a titania matrix with top-down hard X-ray lithography of nanocrystalline cerium oxide. At first the titania mesopores have been impregnated with the ceria precursor solution and then exposed to hard X-rays, which triggered the formation of crystalline cerium oxides within the pores inducing the in situ growth of nanoparticles with average size of 4 nm. It has been observed that the type of coordinating agent in the solution plays a primary role in the formation of nanoparticles. Different patterns have been also produced through deep X-ray lithography by spatially controlling the nanoparticle growth on the micrometer scale. The radical scavenging role of the nanocomposite films has been tested using as a benchmark the UV photodegradation of rhodamine 6G. After impregnation with a rhodamine 6G solution, samples with and without ceria have shown a remarkably different response upon exposure to UV light. The dye photodegradation on the surface down because of the antioxidation effect of ceria nanoparticles.

The controlled release of nanoparticles from a hybrid organic-inorganic surface allows for developing several applications based on a slow delivery of oxygen scavengers into specific environments We have successfully grafted ceria nanoparticles on a hybrid film surface and tested their release in a buffer solution; the tests have shown that the particles are continuously delivered within a time scale of hours The hybrid film has been synthesized using 3-glycidoxypropyltrimethoxysilane as precursor alkoxide; the synthesis has been performed in highly basic conditions to control the polycondensation reactions of both organic and inorganic networks via controlled aging of the solution. Only films prepared from aged solutions are able to graft ceria nanoparticles on their surface. The ceria nanoparticles have been characterized by X-ray diffraction, transmission electron microscopy and UV-vis spectroscopy, the hybrid films have been analyzed by Fourier transform infrared spectroscopy, atomic force microscopy and Raman spectroscopy. Raman imaging has been used for the release test The hybrid film-ceria nanoparticles system fulfils the requirements of optical transparency and stability in buffer solutions which are necessary for biomedical applications.

A study on the electrochemical deposition of Zr on platinum, gold, and boron doped diamond (BDD) from 1-butyl-1-methylpyrrolidinium-bis(trifuoromethylsulphonyl) imide is presented in this work. The electrochemical behavior of zirconium ions was investigated by cyclic voltammetries and chronopotentiometries, allowing establishing the mechanism of deposition. Deposition tests were carried out at different potentials and the related samples were analyzed by SEM and EDX. Structural and chemical analyses indicate that the obtained deposits are constituted by metallic zirconium. According to the electrochemistry of zirconium and based on the experimental results, the mechanism is Zr(IV) ⇒ Zr(II) ⇒ Zr.

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.

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. Combining nanoceria and fulleropyrrolidine in a tethered nanosystem allows for efficient scavenging of reactive oxygen species and improved protection of mouse fibroblast cells exposed to a UV insult.

Fabrication of graphene nanocomposite films via sol-gel chemistry is still a challenging task because of the low solubility of graphene in common solvents. In the present work we have successfully developed a suitable synthesis method employing a solution of exfoliated graphene in 1-vinyl-2-pyrrolidone that is added to an anhydrous sol of silicon tetrachloride in ethanol. Thin graphene-silica films with high optical transparency have been obtained; the graphene sheets are composed of two layers and do not aggregate at a large range of concentrations upon incorporation into the matrix. Thermal processing of the silica films allows complete removal of 1-vinyl-2-pyrrolidone without oxidation or degradation of the graphene sheets which are embedded in the oxide.

The present work is aimed at developing a titania-based mesoporous film with catalytic properties toward organophosphate pesticides by combining two different approaches: the molecular imprinting and the self-assembly with a supramolecular template. The mesoporosity of the material has been obtained by using a tri-block copolymer (Pluronic F127) as a micellar template while the molecular imprinted cavities have been templated by a complex between La3+ and bis-4-nitro-phenyl-phosphate. The template removal allowed opening, in one step, both the mesopores and the imprinted cavities with a simultaneous estimation of the active sites. The catalytic activity of the molecularly imprinted and not imprinted films toward the pesticide Paraoxon (R) has been evaluated by means of UV-Vis spectroscopy titration of the 4-nitro-phenolate released by the Paraoxon (R) hydrolysis. The analysis of the initial rates of molecularly imprinted and not imprinted films has shown that the presence of a very low number of molecular cavities improves the catalytic properties of the imprinted film when compared to the not imprinted films and the background hydrolysis.

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 nanopartides (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.

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 O 2 to H 2 O 2 , 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 Ce 4+ and Ce 3+ , 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).

A new type of mesostructured hybrid organic-inorganic film has been synthesised by evaporation-induced self-assembly using 3-glycidoxypropyltrimethoxysilane as the precursor and a tri-block copolymer, Pluronic F127, as the template. The chemistry has been tuned to form bridged polysilsesquioxanes that self-organise into ordered lamellar structures. Controlled aging under highly basic conditions, which has been monitored by Raman and infrared spectroscopy, has been used to obtain the layered ordered hybrid structures in the precursor sol. The pH of the sol has been adjusted to form the micelles that act as templates during solvent evaporation. The self-assembly of the system has been studied in situ by small and wide angle X-ray scattering using a synchrotron light source, which has confirmed both the formation of hybrid layered structures and the long-range organization of the mesophase in the hybrid films. The present approach allows ordering the hybrid film on two different length scales; at the end of film processing, hybrid crystals are incorporated into the pore walls and the micelles are arranged within the films with long range order.

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 plantArtemisia 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 twoArtemisiaspecies (A.abrotanumandA.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 inPlasmodium falciparumcultures inin vitroexperiments. The antiplasmodial effect has been assessed using increasing doses of AgNPs (0.6 to 7.5 mu g/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 afterA.abrotanum-AgNPs (1) treatment respect toA.arborescens-AgNPs (2), and AgNPs (3) derived from a classical chemical synthesis. Moreover, after 24 and 48 hours ofA.abrotanum-AgNPs (1) treatment, the parasite growth was locked in the ring stage, evidencing the effect of these nanoparticles to hinder the maturation ofP.falciparum. The anti-malarial activity ofA.abrotanum-AgNPs (1) on pRBCs was demonstrated to be higher than that ofA.arborescens-AgNPs (2).

The protection of organic and hybrid organic-inorganic materials from X-ray damage is a fundamental technological issue for broadening the range of applications of these materials. In the present article it is shown that doping hybrid films with fullerenes C-60 gives a significant reduction of damage upon exposure to hard X-rays generated by a synchrotron source. At low X-ray dose the fullerene molecules act as 'radical scavengers', considerably reducing the degradation of organic species triggered by radical formation. At higher doses the gradual hydroxylation of the fullerenes converts C-60 into fullerol and a bleaching of the radical sinking properties is observed.

Hybrid films prepared from 3-glycidoxypropyltrimethoxysilane have been widely used as organic-inorganic materials for several applications. Tailoring the coating surface should disclose new possibilities of applications in biomaterials as functional interfaces for cells and enzymes. In this work we have designed the synthesis of 3-glycidoxypropyltrimethoxysilane hybrid films to modify the surface properties without additional surface functionalization steps. The pH of the precursor sols has been changed from highly basic to acidic and neutral pH and then the sols have been used to deposit highly transparent films. The analysis by infrared spectroscopy has shown that the synthetic conditions allow tuning the degree of condensation of the silica network and the percentage of epoxide ring opening. A precise control of these two parameters enables the formation of a smart surface library where hydroxyl or epoxide groups or the mixed presence of both change the hydrophobicity of the surface and thus its capability of binding molecules and nano-objects.

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. [Display omitted]

The possibility of extending the technological applications of photocatalytic mesoporous titania films relies upon the capability of lowering the processing temperature while maintaining its functional properties. Here we present a synthesis of mesoporous titania films, which makes use of a partially fluorinated surfactant Zonyl FS300 as a mesostructuring agent. The photoinduced degradation activity has been followed by FTIR spectroscopy as a function of the films' thermal annealing, ranging from 150 up to 400 degrees C, by using stearic acid as a model compound. The results have been compared with the benchmark templating agent Pluronic F127 and highlighted a constantly higher activity of the Zonyl-templated films, up to 50%, throughout the range of the temperatures analyzed. Raman spectroscopy indicates that Zonyl FS300 is capable of producing nanosized titania crystals at temperatures lower than Pluronic F127. This explains the different photocatalytic response of the corresponding mesoporous thin films processed at low temperatures.

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 degrees C for up to 24 hours, on the main functional and kinematic parameters. Spermatozoa were incubated with 0, 22, 44, and 220 mu g/mL of CeO2 NPs at 4 degrees 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. (C) 2016 Elsevier Inc. All rights reserved.

Among the myriad microfabrication approaches, Deep X-ray Lithography (DXRL) takes advantage of the high penetration depth of hard X-rays. For the first time, this feature has been exploited for the precise control of surface chemical functionalities on a thick porous ceramic material. As a proof of concept, porous alumina membranes with controlled thickness (50 mu m) have been chosen to test the potential of DXRL. The Al2O3 membranes were decorated with fluoro- and amino-silanes. These functionalized ceramic membranes were exposed to hard X-rays in a synchrotron facility, which allowed for the selective decomposition of the chemical functionalities in controlled areas. The water contact angle of hydrophobic-functionalized samples was measured to confirm the decomposition of the fluoro-silane in the exposed area, and water diffusion through the 200 nm pores of the alumina membranes was observed to occur only in the exposed area. The patterned amino-functionalized Al2O3 samples were tested with an alcoholic solution containing Au cations, where it was found that gold nanoparticles only formed in the unexposed areas, whereas the amino functionality survived the radiation damage induced by the X-rays.

An innovative approach towards the physico-chemical tailoring of zinc oxide thin films is reported. The films have been deposited by liquid phase using the sol-gel method and then exposed to hard X-rays, provided by a synchrotron storage ring, for lithography. The use of surfactant and chelating agents in the sol allows easy-to-pattern films made by an organic-inorganic matrix to be deposited. The exposure to hard X-rays strongly affects the nucleation and growth of crystalline ZnO, triggering the formation of two intermediate phases before obtaining a wurtzite-like structure. At the same time, X-ray lithography allows for a fast patterning of the coatings enabling microfabrication for sensing and arrays technology.

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 m(2) 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.

Background: Cerium 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. Methods: The 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 mu g/mL) and stored at 4 degrees C for 96 h. Analyses of kinematic parameters (computer assisted sperm analysis, CASA), integrity of membranes (PI/PSA staining), ROS production (H(2)DCFDA 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. Results: Exposure 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. Conclusions: We 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 genotoxic effects of CeO2 NPs. These effects could not be related to an antioxidant activity of CeO2 NPs, since ROS levels in exposed cells were similar to those of unexposed ones.

A challenge in neurology is the lack of efficient brain-penetrable neuroprotectants targeting multiple disease mechanisms. Plasmonic gold nanostars are promising candidates to deliver standard-of-care drugs inside the brain but have not been trialed as carriers for neuroprotectants. Here, we conjugated custom-made peptide dendrimers (termed H3/H6), encompassing motifs of the neurotrophic S100A4-protein, onto star-shaped and spherical gold nanostructures (H3/H6-AuNS/AuNP) and evaluated their potential as neuroprotectants and interaction with neurons. The H3/H6 nanostructures crossed a model blood-brain barrier, bound to plasma membranes, and induced neuritogenesis with the AuNS, showing higher potency/efficacy than the AuNP. The H3-AuNS/NP protected neurons against oxidative stress, the H3-AuNS being more potent, and against Parkinson's or Alzheimer's disease (PD/AD)-related cytotoxicity. Unconjugated S100A4 motifs also decreased amyloid beta-induced neurodegeneration, introducing S100A4 as a player in AD. Using custom-made dendrimers coupled to star-shaped nanoparticles is a promising route to activate multiple neuroprotective pathways and increase drug potency to treat neurodegenerative disorders.

•3D printing of magnetic stimuli hydrogels has shown promise in low-resolution extrusion printing but faces limitations using high-resolution VAT polymerisation.•A new two-step capping method is developed for stabilising SPIONs into water-based photoresins that requires no agitation to maintain homogenous suspension during printing.•This methodology introduces added functionality and eliminates mechanical agitation to produce functional 3D printed hydrogels. 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. [Display omitted]

Superparamagnetic iron oxide nanoparticles of magnetite have been grafted on the surface of a hybrid organic-inorganic film prepared using an organically modified alkoxide, 3-glycidoxypropyltrimethoxysilane, as precursor. A solventless synthesis of the hybrid films at high pH has been employed and the surface chemistry of the deposited films has been processed by controlling the aging time of the sol. The films have been characterized by FTIR, Raman and UV spectroscopy and grazing incidence X-ray diffraction. Films prepared with fresh sols have shown a mixed presence of epoxides and hydroxyls on the surface, which enabled the successful grafting of the iron oxide nanoparticles. Films from aged sols, which contain only hydroxyls, have failed to bind the iron particles but have instead shown the capability of grafting ceria nanoparticles. This method has, therefore, allowed a direct grafting of nanoparticles on the hybrid surface without any post-synthetic functionalization step. Moreover, the phase transition induced in iron oxide nanoparticles by means of a laser beam has been exploited to pattern the film surface creating different domains of magnetite and hematite.

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. [GRAPHICS]

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. [Display omitted]