Very Large Pore Mesoporous Bioactive Silicate Glasses: Comparison of Behavior toward Classical Mesoporous Bioactive Glasses in Terms of Drug Loading/Release and Bioactivity.

Considering the increase in patients who suffer from osteoporosis and the bone defects that occur in these patients, bone tissue regeneration is a promising option to solve this problem. To achieve a synergistic effect between the synthesis of a proper structure and bioactive/pharmaceutical activity, ions with a physiological effect can be added to silica structures, such as Ca, thanks to its bioactive behavior, and Ga for its antibacterial and anticancer action. In this work, the synthesis of large pore mesoporous silica (LPMS), potential bioactive glasses containing Ca and Ga, has been studied.

An insight into REEs recovery from spent fluorescent lamps: Evaluation of the affinity of an NH-13X zeolite towards Ce, La, Eu and Y.

The constantly increasing demand of Rare Earth Elements (REEs) made them to be part of the so-called "critical elements" indispensable for the energy transition. The monopoly of only a few countries, the so-called balance problem between demand and natural abundance, and the need to limit the environmental costs of their mining, stress the necessity of a recycling policy of these elements. Different methods have been tested for REEs recovery.

Very Large Pores Mesoporous Silica as New Candidate for Delivery of Big Therapeutics Molecules, Such as Pharmaceutical Peptides.

The synthesis of a scaffold that can accommodate big molecules with a pharmaceutical role is important to shield them and maintain their biological activity. In this field, silica particles with large pores (LPMS) are innovative supports. Large pores allow for the loading of bioactive molecules inside the structure and contemporarily their stabilization and protection.

Alginate Beads Containing Cerium-Doped Mesoporous Glass and Curcumin: Delivery and Stabilization of Therapeutics.

Cancer is a leading cause of death worldwide, its genesis and progression are caused by homeostatic errors, and reactive oxygen species play a major role in promoting aberrant cancer homeostasis. In this scenario, curcumin could be an interesting candidate due to its versatile antioxidant, anti-inflammatory, anti-tumor, anti-HIV, and anti-infection properties. Nonetheless, the major problem related to its use is its poor oral bioavailability, which can be overcome by encapsulating it into small particles, such as hydrogel beads containing mesoporous silica.

Curcumin-Based β-Diketo Ligands for Ga: Thermodynamic Investigation of Potential Metal-Based Drugs.

Curcumin is known for its therapeutic properties; among these, antioxidant, anti-inflammatory and anti-cancer ones stand out. Besides, curcumin metal complexes have shown widespread application in medicine and can be exploited as lead structures for developing metal-based drugs. Unfortunately, curcumin is poorly bioavailable, mainly due to its instability in physiological conditions; this weakness is tightly connected to the presence of the β-diketo moiety undergoing tautomeric equilibrium.

Cerium Containing Bioactive Glasses: A Review.

Bioactive glasses (BGs) for biomedical applications are doped with therapeutic inorganic ions (TIIs) in order to improve their performance and reduce the side effects related to the surgical implant. Recent literature in the field shows a rekindled interest toward rare earth elements, in particular cerium, and their catalytic properties. Cerium-doped bioactive glasses (Ce-BGs) differ in compositions, synthetic methods, features, and assessment.

Cell Proliferation to Evaluate Preliminarily the Presence of Enduring Self-Regenerative Antioxidant Activity in Cerium Doped Bioactive Glasses.

(1) Background: a cell evaluation focused to verify the self-regenerative antioxidant activity is performed on cerium doped bioactive glasses. (2) Methods: the glasses based on 45S5 Bioglass, are doped with 1.2 mol%, 3.

Solid-State Nonlinear Optical Properties of Mononuclear Copper(II) Complexes with Chiral Tridentate and Tetradentate Schiff Base Ligands.

Salen-type metal complexes have been actively studied for their nonlinear optical (NLO) properties, and push-pull compounds with charge asymmetry generated by electron releasing and withdrawing groups have shown promising results. As a continuation of our research in this field and aiming at solid-state features, herein we report on the synthesis of mononuclear copper(II) derivatives bearing either tridentate NO Schiff bases L and pyridine as the forth ancillary ligand, [Cu(L)(py)](ClO) (-), or unsymmetrically-substituted push-pull tetradentate NO Schiff base ligands, [Cu(5-A-5'-D-saldpen/chxn)] (-), both derived from 5-substituted salicylaldehydes (sal) and the diamines (1,2)-1,2-diphenylethanediamine (dpen) and (1,2)-1,2-diaminocyclohexane (chxn). All compounds were characterized through elemental analysis, infrared and UV/visible spectroscopies, and mass spectrometry in order to guarantee their purity and assess their charge transfer properties.

Cytocompatibility of Potential Bioactive Cerium-Doped Glasses based on 45S5.

The cytocompatibility of potential bioactive cerium-containing (Ce/Ce) glasses is here investigated by preparing three different glasses with increasing amount of doping CeO₂ (1.2, 3.6 and 5.

Preparation and Luminescence Properties of Ba₅Si₈O Long Persistent Phosphors Doped with Rare-Earth Elements.

The phosphors of formula Ba₅Si₈O:Eu,Dy were synthesized and studied in order to improve their properties. Their synthesis conditions were evaluated as a function of precursors, crucible composition, flux agents, dopants and temperatures. The samples were characterised by means of a systematic investigation through elemental, kinetic, mineralogical (both qualitative and quantitative), and morphological analysis.

Role of cerium oxide in bioactive glasses during catalytic dissociation of hydrogen peroxide.

The addition of cerium oxide to bioactive glasses, important materials for bone tissue regeneration, has been shown to induce multifunctionality, combining a significant bioactivity with antioxidant properties. We provide a real time investigation of the evolution of the electronic properties of highly diluted cerium ions in a liquid environment containing hydrogen peroxide - the most abundant reactive oxygen species in living cells. This challenging task is undertaken by means of high-energy resolution fluorescence detected by X-ray absorption near-edge spectroscopy at the Ce L3 edge.

Highly-Bioreactive Silica-Based Mesoporous Bioactive Glasses Enriched with Gallium(III).

Beneficial effects in bone cell growth and antibacterial action are currently attributed to Ga ions. Thus, they can be used to upgrade mesoporous bioactive glasses (MBGs), investigated for tissue engineering, whenever they released therapeutic amounts of gallium ions to the surrounding medium. Three gallium-enriched MBGs with composition (in mol %) SiO₂-CaO-P₂O₅-5Ga₂O₃, being = 70, = 15, = 10 for ; = 80, = 12, = 3 for ; and = 80, = 15, = 0 for , were investigated and compared with the gallium-free 80SiO₂-15CaO-5P₂O₅ MBG ().

SiO₂-CaO-P₂O₅ Bioactive Glasses: A Promising Curcuminoids Delivery System.

In this paper, we report the study of the loading and the release of curcuminoids by bioactive glasses (BG) and mesoporous bioactive glasses (MBG). Through a detailed spectroscopic study, it was possible to determine the amount and the type of molecules released in water and in simulated body fluid (SBF). In particular, curcumin and K2T21 show a good ability to be released in di-keto and keto-enolic form, depending from the pH.

Evidence of catalase mimetic activity in Ce(3+)/Ce(4+) doped bioactive glasses.

The ability of Ce-containing bioactive glasses to inhibit oxidative stress in terms of reduction of hydrogen peroxide, by mimicking the catalase enzyme activity is demonstrated here for the first time. The antioxidant properties of three bioactive glasses containing an increasing amount of CeO2 have been evaluated by following the degradation of hydrogen peroxide with time after immersion in H2O2 aqueous solutions with different concentration. XPS and UV-vis measurements allowed us to determine the Ce(3+)/Ce(4+) ratio in the bulk and on the glass surface, and to correlate it with the ability of the samples to show catalase mimetic activity.

In vitro antibacterial capacity and cytocompatibility of SiO-CaO-PO meso-macroporous glass scaffolds enriched with ZnO.

Zn ions exhibit osteogenic, angiogenic and antimicrobial properties. For this reason, they are often added in small amounts to bioceramics being investigated for bone tissue engineering. In this paper, the cytocompatibility and antibacterial properties of 80% SiO-15% CaO-5% PO (mol%) mesoporous bioactive glass (MBG) scaffolds substituted with 4.

Conjugation of amino-bioactive glasses with 5-aminofluorescein as probe molecule for the development of pH sensitive stimuli-responsive biomaterials.

Bioceramics, such as silica-based glasses, are widely used in bone and teeth restoration. Nowadays, the association between nanotechnology and pharmacology is one of the most promising research fields in cancer therapy. The advanced processing methods and new chemical strategies allow the incorporation of drugs within them or on their functionalized surfaces.

New formulation of functionalized bioactive glasses to be used as carriers for the development of pH-stimuli responsive biomaterials for bone diseases.

The aim of the present contribution is to prepare a functionalized bioactive glass potentially useful as prosthetic material, but also able to release organic molecules in response to a change of the pH environment. By this approach it is possible to develop devices which can be used for a triggered drug release in response to specific stimuli; this is an attractive research field, in order to avoid either systemic and/or local toxic effects of drugs. In particular, in the present paper we report data related to the development of a new formulation of bioactive glasses, their functionalization with organic molecules to obtain a pH-sensitive bond, their physicochemical characterization and in vitro bioactivity in simulated biological fluids (SBF), and organic molecule delivery tests at different pH.

Sr-containing hydroxyapatite: morphologies of HA crystals and bioactivity on osteoblast cells.

A series of Sr-substituted hydroxyapatites (HA), of general formula Ca(10-x)Srx(PO4)6(OH)2, where x=2 and 4, were synthesized by solid state methods and characterized extensively. The reactivity of these materials in cell culture medium was evaluated, and the behavior towards MG-63 osteoblast cells (in terms of cytotoxicity and proliferation assays) was studied. Future in vivo studies will give further insights into the behavior of the materials.

Gallium-containing phosphosilicate glasses: functionalization and in-vitro bioactivity.

A gallium containing glass 45.7SiO2·24.1Na2O·26.

Study of the structural role of gallium and aluminum in 45S5 bioactive glasses by molecular dynamics simulations.

The structural properties of phosphosilicate glasses based on the 45S5 Bioglass doped with gallium and aluminum (46.2 SiO2·24.3Na2O·26.

Gold-containing bioactive glasses: a solid-state synthesis to produce alternative biomaterials for bone implantations.

A new melted bioactive system containing gold nanoparticles (AuNPs) was prepared exploiting a post-synthesis thermal treatment that allows one to modify crystal phases and nature, shape and distribution of the gold species in the glass-ceramic matrix as evidenced by UV-visible spectroscopy, transmission electron microscopy and powder X-ray diffraction analysis. In human MG-63 osteoblasts the presence of Au(n)(+) species caused an increase of lactate dehydrogenase leakage and malonyldialdehyde production, whereas Hench's Bioglass HAu-600-17 containing only AuNPs did not cause any effect. In addition, HAu-600-17 caused in vitro hydroxyapatite formation and an increase of specific surface area with a controlled release of gold species; this material is then suitable to be used as a model system for the controlled delivery of nanoparticles.

Magnesium- and strontium-co-substituted hydroxyapatite: the effects of doped-ions on the structure and chemico-physical properties.

The present study is aimed at investigating the contribution of two biologically important cations, Mg(2+) and Sr(2+), when substituted into the structure of hydroxyapatite (Ca(10)(PO(4))(6)(OH)(2),HA). The substituted samples were synthesized by an aqueous precipitation method that involved the addition of Mg(2+)- and Sr(2+)-containing precursors to partially replace Ca(2+) ions in the apatite structure. Eight substituted HA samples with different concentrations of single (only Mg(2+)) or combined (Mg(2+) and Sr(2+)) substitution of cations have been investigated and the results compared with those of pure HA.

Mesoporous bioactive scaffolds prepared with cerium-, gallium- and zinc-containing glasses.

Mesoporous bioactive glass scaffolds (MBG_Scs), based on 80% SiO(2)-15% CaO-5% P(2)O(5) (in mol.%) mesoporous sol-gel glasses substituted with Ce(2)O(3), Ga(2)O(3) (both 0.2% or 1.

Gallium-containing phospho-silicate glasses: synthesis and in vitro bioactivity.

A series of Ga-containing phospho-silicate glasses based on Bioglass 45S5, having molar formula 46.2SiO2·24.3Na2O·26.