Silica Nanostructures Research Articles

A sinterless, low-temperature route to 3D print nanoscale optical-grade glass.

Three-dimensional (3D) printing of silica glass is dominated by techniques that rely on traditional particle sintering. At the nanoscale, this limits their adoption within microsystem technology, which prevents technological breakthroughs. We introduce the sinterless, two-photon polymerization 3D printing of free-form fused silica nanostructures from a polyhedral oligomeric silsesquioxane (POSS) resin. Contrary to particle-loaded sacrificial binders, our POSS resin itself constitutes a continuous silicon-oxygen molecular network that forms transparent fused silica at only 650°C. This temperature is 500°C lower than the sintering temperatures for fusing discrete silica particles to a continuum, which brings silica 3D printing below the melting points of essential microsystem materials. Simultaneously, we achieve a fourfold resolution enhancement, which enables visible light nanophotonics. By demonstrating excellent optical quality, mechanical resilience, ease of processing, and coverable size scale, our material sets a benchmark for micro- and nano-3D printing of inorganic solids.

Effect of Nanostructured Silica Additives on the Extrusion-Based 3D Concrete Printing Application

Recently, 3D printing technology has become more popular in the field of construction. For the extrusion-based 3D concrete printing (3DCP) process, the cementitious material needs to be strong and flowable enough to ensure buildability and pumpability. Nanostructured silica, a kind of additive, has been used to modify the 3DCP concrete to meet these requests. However, most previous studies focused on the effect of nanostructured silica on rheological properties and failed to link the obtained rheological properties of nanostructured-silica-modified cementitious materials to the performance in 3D printing. In this paper, the 3DCP mixture based on premix cement, river sand, silica fume, and water was modified by different dosages of nanostructured silica (from 0.25% to 1.00% by the total weight of the 3DCP mixture). The effects of nanostructured silica on the rheological, hydration, printing, and microstructural properties were determined by rheological tests, stress growth tests, setting time tests, printing tests, and scanning electron microscopy (SEM) tests, respectively. This paper revealed that the nanostructured silica has a positive effect on 3DCP buildability but negatively affects the printing quality, which fits the effect of nanostructured silica on the rheological properties. Hence, the determined rheological properties can qualitatively evaluate the printing performance of nanostructured-silica-modified cementitious materials.

Synthesis of nanostructured silica particles for controlled release of ascorbic acid: Microstructure features and In Vitro scratch wound assay.

To date, the long term stability of ascorbic acid (AA) under physiological conditions represents a major issue for wound healing and tissue regeneration applications. In this study, ascorbylphosphate (AP) was loaded into silica nanoparticles (SiNPs) through a simple one-step procedure, in which sphericalshaped porous SiNPs were obtained via hydrolysis/condensation of tetraethylorthosilicate (TEOS) in the presence of bicarbonate salt and ammonia. The as-prepared SiNPs were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and Fourier Transformer Infrared Spectrophotometer (FTIR). Incorporation of bicarbonate salt resulted in the formation of spherical SiNPs with an average diameter of 460±89nm, while further increase of bicarbonate salt led to the formation of silica sheet-like structures.The AP-loaded SiNPs exhibited high loading efficiency from 92.3- 81.5%, according to AP content and sustained release over 3 days. According to cell viability assay, the obtained AP-enriched SiNPS showed no toxicity and supportive effect to the proliferation of human skin fibroblast cells (HSF) at a concentration less than 200μg/mL. Moreover, it was observed that the wound closure percentage (%) after 24h was also shown to increase to 74.1±3.1% for 20AP-loaded SiNPs compared to control samples (50.1±1.8%). The obtained results clearly demonstrated that the developed SiNPs formulation exhibits optimal microstructure features to maintain a sustained release of AA at wound bed for the healing of skin tissue, including acute and chronic wounds. This article is protected by copyright. All rights reserved.

Full Site-Specific Addressability in DNA Origami-Templated Silica Nanostructures.

DNA nanotechnology allows for the fabrication of nanometer-sized objects with high precision and selective addressability as a result of the programmable hybridization of complementary DNA strands. Such structures can template the formation of other materials, including metals and complex silica nanostructures, where the silica shell simultaneously acts to protect the DNA from external detrimental factors. However, the formation of silica nanostructures with site-specific addressability has thus far not been explored. Here, it is shown that silica nanostructures templated by DNA origami remain addressable for post silicification modification with guest molecules even if the silica shell measures several nm in thickness. The conjugation of fluorescently labeled oligonucleotides is used to different silicified DNA origami structures carrying a complementary ssDNA handle as well as DNA-PAINT super-resolution imaging to show that ssDNA handles remain unsilicified and thus ensure retained addressability. It is also demonstrated that not only handles, but also ssDNA scaffold segments within a DNA origami nanostructure remain accessible, allowing for the formation of dynamic silica nanostructures. Finally, the power of this approach is demonstrated by forming 3D DNA origami crystals from silicified monomers. These results thus present a fully site-specifically addressable silica nanostructure with complete control over size and shape.

Microwave Irradiation vs. Structural, Physicochemical, and Biological Features of Porous Environmentally Active Silver–Silica Nanocomposites

Heavy metals and other organic pollutants burden the environment, and their removal or neutralization is still inadequate. The great potential for development in this area includes porous, spherical silica nanostructures with a well-developed active surface and open porosity. In this context, we modified the surface of silica spheres using a microwave field (variable power and exposure time) to increase the metal uptake potential and build stable bioactive Ag2O/Ag2CO3 heterojunctions. The results showed that the power of the microwave field (P = 150 or 700 W) had a more negligible effect on carrier modification than time (t = 60 or 150 s). The surface-activated and silver-loaded silica carrier features like morphology, structure, and chemical composition correlate with microbial and antioxidant enzyme activity. We demonstrated that the increased sphericity of silver nanoparticles enormously increased toxicity against E. coli, B. cereus, and S. epidermidis. Furthermore, such structures negatively affected the antioxidant defense system of E. coli, B. cereus, and S. epidermidis through the induction of oxidative stress, leading to cell death. The most robust effects were found for nanocomposites in which the carrier was treated for an extended period in a microwave field.

Influence of surface nanostructures on the catalytic recombination of hyperthermal non-equilibrium flow

One of the key challenges for accurate prediction of hypersonic aerodynamic heating is the exothermic uncertainty due to the complex surface catalytic recombination effect, which is caused by the strong interactions between highly non-equilibrium dissociated gas and the thermal protection material surface. Employing engineered surface morphology to improve thermal protection effects has been proposed, but its effects on surface catalytic recombination remain unclear. To address this problem, this work employs the reactive molecular dynamics method to investigate the surface adsorption and recombination characteristics of continuous impingement of atomic oxygen upon eight different nano-structured silica surfaces. A parametric study of the influences of the gas incident angles and the surface structural parameters, i.e., roughness factor and surface fraction, is conducted. The results show that the surface catalytic recombination performance is very sensitive to the incident angle of the incoming gas, and the presence of nanostructures increases the recombination rate. The influence of surface morphology shows a complicated feature, where nanostructures with moderated fin height and high surface fraction are beneficial for the inhibition of surface recombination effects, leading to reduced exothermic heat release. Such microscopic revelation of the surface morphology effect is helpful for accurate prediction of aerodynamic heat and provides guidance for the surface engineering of optimized morphology to achieve improved thermal protection effect.

Superhydrophobic Surface on Insulators by Using Perfluoropolyether-Functionalized Silica Nanostructures for Preventing Stress Corrosion Cracking at the Pin–Cement Junction

Stress corrosion accounts for 52% of the recorded breakdown of insulators utilized in transmission lines which may interfere with the reliability of power utilities. The suggested etching-free treatment is a workable environmentally benign method to prevent stress corrosion, even in old insulators with more excellent surface imperfections or cracks. The resilient slippery coating is developed on an insulator surface to address the challenges by infusing perfluoropolyether, lubricating oil into a porous nano-silica surface. The proposed coating layer, thickness 35.4 μm, exhibits superhydrophobicity with contact angle─160°, contact angle hysteresis─4°, self-healing, corrosion resistance with a corrosion rate of 2 × 10–3 mm/Y, Icorr 2.01 × 10–7 A/cm2, and 98% anti-bacterial adhesion performance against sulfate reducing bacterial stains. The outcome of this research is expected to pave the way for an approach to the future creation of incredibly robust etching-free coatings for insulators.

Efficacy evaluation of a novel oral silica-based vaccine in inducing mucosal immunity against Mycoplasma hyopneumoniae

Mycoplasma hyopneumoniae, the main etiological agent of Porcine Enzootic Pneumonia, is widely spread in swine production worldwide. Its prevention is of great interest for the productive system, since its colonization in the lung tissue leads to intense production losses. This study aimed to compare the M. hyopneumoniae shedding and acute-phase response in 30 pigs submitted to different vaccination protocols: an experimental oral vaccine using a nanostructured mesoporous silica (SBA-15) as adjuvant (n = 10); an intramuscular commercially available vaccine at 24 days of age (n = 10); and a control group (n = 10) following experimental challenge with M. hyopneumoniae. Laryngeal and nasal swabs were collected weekly and oral fluids were collected at 7, 10, 14, 17, 23, 28, 35, 42, and 49 days post-infection to monitor pathogen excretion by qPCR. Nasal swabs were also used to detect anti-M. hyopneumoniae IgA by ELISA. Blood samples were collected for monitoring acute phase proteins. The antibody response was observed in both immunized groups seven days after vaccination, while the control group became positive for this immunoglobulin at 4 weeks after challenge. Lung lesion score was similar in the immunized groups, and lower than that observed in the control. SBA-15-adjuvanted oral vaccine provided immunological response, decreased shedding of M. hyopneumoniae and led to mucosal protection confirmed by the reduced pulmonary lesions. This study provides useful data for future development of vaccines against M. hyopneumoniae.

Local structural effects of Gd3+ ions incorporation in shell of nanostructured silica core – alumina rich shell microspheres

Non-crystalline nanostructured silica core – alumina rich shell microspheres, with Gd ions in the shell were obtained by sol-gel procedure following a synthesis route based on the Stöber method. The samples were characterized by DTA/TGA, XRD, SEM and TEM, EPR, solid-state NMR and XPS techniques. The effect of increasing Gd ions content on the local structure in alumina rich shell and at its interface with silica core was investigated. It was also found that increasing the concentration of the paramagnetic ions leads to a modification of the local magnetic field at sites of neighboring aluminum and silicon ions. Gadolinium ions are distributed in the aluminum sites from alumina rich shell. As result of increasing the gadolinium incorporation at the core-shell interface the diffusion of aluminum in the silica network, as well as the migration of the silicon in the alumina rich shell, are enhanced. Therefore, Si-O-Al bridges are formed at the interface, leading to stable non-crystalline structures, with Gd ions on the external layer of the shell, as proved by XPS, having potential application as contrast agents for magnetic resonance imaging (MRI).

Electrospun Multilayered Films Based on Poly(3-hydroxybutyrate-co-3-hydroxyvalerate), Copolyamide 1010/1014, and Electrosprayed Nanostructured Silica

In this research, bio-based electrospun multilayered films for food packaging applications with good barrier properties and close to superhydrophobic behavior were developed. For this purpose, two different biopolymers, a low-melting point and fully bio-based synthetic aliphatic copolyamide 1010/1014 (PA1010/1014) and the microbially synthesized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and food-contact-complying organomodified silica (SiO2) nanostructured microparticles, were processed by electrospinning. The production of the multilayer structure was finally obtained by means of a thermal post-treatment, with the aim to laminate all of the components by virtue of the so-called interfiber coalescence process. The so developed fully electrospun films were characterized according to their morphology, their permeance to water vapor and oxygen, the mechanical properties, and their water contact angle properties. Interestingly, the annealed electrospun copolyamide did not show the expected improved barrier behavior as a monolayer. However, when it was built into a multilayer form, the whole assembly exhibited a good barrier, an improved mechanical performance compared to pure PHBV, an apparent water contact angle of ca. 146°, and a sliding angle of 8°. Consequently, these new biopolymer-based multilayer films could be a bio-based alternative to be potentially considered in more environmentally friendly food packaging strategies.

MRI-guided dual-responsive anti-tumor nanostructures for synergistic chemo-photothermal therapy and chemodynamic therapy.

Image-guided stimulus-responsive theranostics are beneficial for identifying malignant lesions and integrating multiple cell-killing mechanisms to enhance tumor cell clearance. Herein, an intelligent dual-responsive nanostructure (HSPMH-DOX) was developed for magnetic resonance imaging (MRI)-guided synergistic chemo-photothermal therapy (PTT) and chemodynamic therapy (CDT). The core-shell nanostructure was synthesized by layering polydopamine (PDA), manganese oxide (MnO2), and hyaluronic acid (HA) onto drug-loaded hollow mesoporous silica nanoparticles (HS). The constructed nanoagent has both endogenous and external dual responses. The tumor microenvironment (pH/GSH) can trigger the degradation of gatekeeper (MnO2 and PDA), resulting in the release of anti-tumor drugs, whereas external near-infrared light irradiation can accelerate the degradation process and generate local overheating, resulting in PTT. Notably, MnO2 can not only consume intracellular GSH to enhance CDT but also release Mn2+ for precise localization of tumor tissues using MRI. Both in vitro and in vivo experiments showed that the prepared dual-response nanoagent satisfied biocompatibility, targeting, and the great efficiency of MRI-guided combined therapy. In animal models, combining chemo-PTT and CDT can eradicate tumors in less than two weeks. This work could pave the way for a wide range of stimulus-responsive synergistic theranostic applications, including MRI, chemo-photothermal therapy, and chemodynmic therapy. STATEMENT OF SIGNIFICANCE: Low bioavailability and severe side effects remain the major limitations of conventional cancer chemotherapy. Image-guided combination therapy can alleviate these problems and improve tumor-specific therapy. In the present study, the anticancer drug doxorubicin was encapsulated in a core-shell hollow mesoporous silica nanostructure (HSPMH-DOX), enabling MRI-guided targeted release under both endogenous and external dual stimuli. Moreover, the photothermal and nanoenzymatic effects of nanomedicine can cause local overheating in the tumor and amplify the intracellular CDT effect, accelerating tumor eradication. Systematic evaluations in vitro and in vivo confirmed that nanomedicine enables highly effective MRI-guided synergistic chemo-photothermal and chemodynamic therapy. This work offers a promising therapeutic strategy for precise anti-tumor applications.

Low-Dimensional Hollow Nanostructures: From Morphology Control to the Release of an Active Pharmaceutical Ingredient

The mechanism guiding the growth of hollow silica nanotubes or nanospheres was unveiled for the first time through in situ liquid-phase transmission electron microscopy, allowing visualization of the morphology of the hydrated species involved in the early stage of material formation. The combined action of a surfactant (F127) and a swelling agent (toluene) was essential for the development of targeted nanostructures, owing to the formation of surfactant-stabilized toluene droplets in the aqueous phase. The quantity of surfactant-stabilized toluene droplets was unambiguously pointed as the key parameter guiding the formation of either tubular or spherical nanostructures. Leveraging on the fundamental understanding of the parameters guiding the formation of hollow silica nanostructures, tubular and spherical carriers were prepared and exploited for the release of an active pharmaceutical ingredient (API). The impregnation of nanotubes and nanospheres with a poorly water-soluble API (curcumin) was investigated, leading to an optimal loading of 20 wt %. The accessibility of nanotubes and nanospheres showed to be highly beneficial to increase the release kinetics of the targeted API in simulated intestinal fluid, opening promising perspectives in the field. Release was more efficient than with other conventional mesoporous silica-based carriers.

Fluorescent Magnetic Mesoporous Nanoprobes for Biotechnological Enhancement Procedures in Gene Therapy

In recent years, nanotechnology has deployed a new set of theragnostic tools, including magnetic resonance contrast agents, nano-delivery systems and magnetic hyperthermia treatments in cancer therapy, exploiting not only the small size of nanoparticles, but also relevant nanoscale properties such as superparamagnetism. Specifically, magnetic nanostructures can be remotely manipulated by external magnetic fields, incrementing their possibilities not only for theragnosis, but also for biotech procedures. Genetic engineering processes involve a set of steps like extracting cells from complex environments, their selection and subsequent cultivation or modification by transfection and can benefit from the use of bioconjugated magnetic nanoparticles. Magnetofection of cells with genes or biological material uploaded on superparamagnetic nanoparticles attracted by a magnetic field greatly increases the efficiency, specificity and speed of the biotechnological procedure in gene transfer systems. This article presents a preliminary investigation into the enhanced transfection efficiency of fluorescent magnetic mesoporous silica nanostructures functionalized with mCherry plasmid, which were used to transfect HeLa cells in just 15 min via magnetic transfection. This method was compared to passive transfection (4 h) and conventional gene transfer using the commercial K2 Transfection System (16 h). The results demonstrated that the fluorescent magnetic mesoporous silica nanostructures were similarly effective to the commercial kit, without the need for reagents that increase costs in clinical therapy. Furthermore, viability assays conducted with HeLa cells showed negligible toxicity at concentrations of up to 50 μg/mL.

Polymer Brushes on Silica Nanostructures Prepared by Aminopropylsilatrane Click Chemistry: Superior Antifouling and Biofunctionality.

In nanobiotechnology, the importance of controlling interactions between biological molecules and surfaces is paramount. In recent years, many devices based on nanostructured silicon materials have been presented, such as nanopores and nanochannels. However, there is still a clear lack of simple, reliable, and efficient protocols for preventing and controlling biomolecule adsorption in such structures. In this work, we show a simple method for passivation or selective biofunctionalization of silica, without the need for polymerization reactions or vapor-phase deposition. The surface is simply exposed stepwise to three different chemicals over the course of ∼1 h. First, the use of aminopropylsilatrane is used to create a monolayer of amines, yielding more uniform layers than conventional silanization protocols. Second, a cross-linker layer and click chemistry are used to make the surface reactive toward thiols. In the third step, thick and dense poly(ethylene glycol) brushes are prepared by a grafting-to approach. The modified surfaces are shown to be superior to existing options for silica modification, exhibiting ultralow fouling (a few ng/cm2) after exposure to crude serum. In addition, by including a fraction of biotinylated polymer end groups, the surface can be functionalized further. We show that avidin can be detected label-free from a serum solution with a selectivity (compared to nonspecific binding) of more than 98% without the need for a reference channel. Furthermore, we show that our method can passivate the interior of 150 nm × 100 nm nanochannels in silica, showing complete elimination of adsorption of a sticky fluorescent protein. Additionally, our method is shown to be compatible with modifications of solid-state nanopores in 20 nm thin silicon nitride membranes and reduces the noise in the ion current. We consider these findings highly important for the broad field of nanobiotechnology, and we believe that our method will be very useful for a great variety of surface-based sensors and analytical devices.

Aminosilane-Modified Ordered Hierarchical Nanostructured Silica for Highly-Selective Carbon Dioxide Capture at Low Pressure

Ordered hierarchical nanostructured silica (OHNS) adsorbents were prepared, and their surface was controllably modified by aminosilanization using two different aminosilanes, one bearing one primary amine unit per molecule (4-aminobutyltriethoxysilane, ABTS) and the other bearing both a primary and a secondary amine (N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane, AAMS). Following physicochemical, structural, morphological, and porosity characterization, the CO2 adsorption performance was evaluated at low pressures (up to 100 mbar) and at different temperatures (25, 45, and 60 °C), including determination of CO2 adsorption–desorption, kinetics, CO2/N2 selectivity, regeneration/cycling, heat of adsorption, and CO2 adsorption under humid conditions. The unique hierarchical silica framework together with the aminosilanization scheme applied resulted in enhanced kinetics and CO2 uptake, the latter being increased with temperature, thus revealing a dominant chemisorption mechanism, which was further evidenced by the increase in the enthalpy of adsorption of the modified materials compared to the pristine OHNS. Among the tested adsorbents, at 100 mbar and 25 °C, the OHNS modified by AAMS yielded the highest CO2 uptake under dry (1.3 mmol/g) and wet (1.9 mmol/g) conditions. Notably, at very low pressure (1 mbar), the CO2 capacity of OHNS-AAMS reached >40% of the material’s total uptake at 1 bar. Compared to the unmodified OHNS, the CO2 capacity of the OHNS-AAMS and OHNS-ABTS increased by approximately 21- and 16-fold, respectively, at 1 mbar and 25 °C. At even lower pressure (0.4 mbar), a capacity of 0.55 mmol/g was evidenced for OHNS-AAMS in dry CO2. A very high CO2/N2 selectivity of the AAMS-modified analogue at low pressure was also obtained, i.e., 13,854 at 50 mbar, confirming the significant increase in CO2-philicity via aminosilanization with aminosilanes bearing combined primary and secondary amine groups. Furthermore, the water affinity of the aminosilane-modified OHNS adsorbents was found to decrease, which is beneficial for capture from humid mixtures. Cyclic stability was confirmed by performing 10 thermal pressure swing adsorption (TPSA) cycles up to 100 mbar. The hierarchical nanostructured silica-based framework and the functionalization scheme presented here render these robust systems promising for selective CO2 capture at low pressures in industrial applications and direct air capture.

Synthesis of superhydrophobic coatings based on silica nanostructure modified with organosilane compounds by sol–gel method for glass surfaces

In the present study, the superhydrophobic coating was synthesized by spherical silica nanostructures modified with organosilane compounds for glass surfaces. To optimize the conditions in terms of cost-effectiveness and create a super-hydrophobic coating with a high contact angle, the response surface method of the central composite design (CCD) model was performed for the StÖber method, and the contact angle was defined as the response surface for the model. Tetraethoxysilane (TEOS) was used as a precursor and poly(dimethylsiloxane) (PDMS) was used to modify the surface of a spherical silica nanostructure synthesized by a one-step sol–gel method using a base catalyst. The accuracy of the research was checked by the contact angle measurement test and an angle of 162° was obtained. XRD, FT-IR, EDS, SEM, DLS, and AFM analyzes were performed to investigate the synthesis of silica nanostructure. Chemical resistance was performed in acidic, neutral, and alkaline environments and the contact angles were 127°, 134°, and 90°, respectively, which indicates that the coating created on the surface glass has good chemical resistance in acidic and neutral environments.

Synthesis and Self-Assembly of Silicon-Containing Azobenzene Liquid Crystalline Block Copolymers

The synthesis and self-assembly of a high interaction parameter silicon-containing liquid crystalline block copolymer (Si-LCBCP) are reported, containing thermally and photo-responsive azobenzene mesogens in the side chains which undergo molecular structural transitions, influencing phase transitions and orientation in the block copolymer. A series of the azobenzene-containing Si-LCBCPs, poly{dimethylsiloxane-b-11-[4-(4-cyanophenylazo)phenoxy]undecane methacrylate}, were synthesized through atom transfer radical polymerization, and the bulk self-assembly as well as the influence of the liquid-crystalline (LC) phase transition of the LC block on the microphase-separated nanostructure of the BCPs is described. As the volume fraction of the PMAAzo block (fPMAAzo) changes from 41 to 71%, lamellar, double gyroid (GYR), orthorhombic Fddd network, hexagonally packed cylindrical (HEX), and body centered cubic nanostructures were obtained. When fPMAAzo = 55–57%, a thermally reversible HEX-GYR-Fddd phase transition induced by the temperature change and LC phase transition was observed. Bulk morphologies are compared with thin-film self-assembly, and pattern transfer into silica nanostructures is demonstrated.

Broadband antireflection coatings with low polarization splitting.

A major problem for optical systems is the polarization splitting occurring at any interface in the event of oblique light. Low-index nanostructured silica layers were produced by overcoating an initial organic structure with silica and subsequent removal of the organic constituents. The nanostructured layers can be tailored to achieve defined low effective refractive indices down to 1.05. They can also be stacked together with homogeneous layers to produce broadband antireflective coatings with very low polarization splitting. Especially thin interlayers that separate the low-index structured layers turned out to be useful to optimize the polarization properties.

Adsorption of tris(8-hydroxyquinolinato)aluminum on phosphoric acid-containing mesoporous silica particles

The effect of the phosphoric acid addition on the nanostructures of the mesoporous silica (MPS) particles and the states of tris(8-hydroxyquinolinato)aluminum (Alq3) in the mesopores were investigated. It was found that the regularity of the mesopores of the MPS particles became irregular by the excessive addition of phosphoric acid. Furthermore, the phosphoric acid on the silica skeletons in the mesopores would strictly interact with the Alq3 molecules, so that the proportion of monomer components with less overlap among the π-π orbitals (i.e., δ-phase-like Alq3 molecules) increased with increasing the phosphoric acid, which was effectively monitored in the fluorescence spectra. It was suggested that the interactions between Alq3 and mesopores were formed not only by hydrogen bonds but also by electrostatic forces between P–O− and aluminum ion, and then the Alq3 molecules were planarly fixed on the surfaces, indicating the importance of the phosphoric acid addition for fixing the photofunctional species on the mesopores.

In vitro evaluation of a hybrid drug-delivery nanosystem for fibrosis prevention incell therapy for Type 1 diabetes.

Background: Implantation of insulin-secreting cells has been trialed as a treatment for Type 1 diabetes mellitus; however, the host immunogenic response limits their effectiveness. Methodology: The authors developed a core-shell nanostructure of upconversion nanoparticle-mesoporous silica for controlled local delivery of an immunomodulatory agent, MCC950, using near-infrared light and validated it in in vitro models of fibrosis. Results: The individual components of the nanosystem did not affect the proliferation of insulin-secreting cells, unlike fibroblast proliferation (p<0.01). The nanosystem is effective at releasing MCC950 and preventing fibroblast differentiation (p<0.01), inflammation (IL-6 expression; p<0.05) and monocyte adhesion (p<0.01). Conclusion: This MCC950-loaded nanomedicine system could be used in the future together with insulin-secreting cell implants to increase their longevity as a curative treatment for Type 1 diabetes mellitus.