Mesoporous Calcium Research Articles

Assessment of the Release Profile of Fibroblast Growth Factor-2-Load Mesoporous Calcium Silicate/Poly-ε-caprolactone 3D Scaffold for Regulate Bone Regeneration

Recent advances in three-dimensional printing technology enable facile and on-demand fabrication of patient-specific bone scaffolds. However, there is still an urgent need for printable biomaterials with osteoinductivity. In the present study, we propose an approach to synthesize fibroblast growth factor-2 loaded-mesoporous calcium silicate nanoparticles. The growth factor loaded-nanoparticles served as fillers of polycaprolactone and then the composite scaffolds with a controlled pore structure were obtained through a fused deposition modeling technique. To evaluate the feasibility of the composite scaffolds in bone tissue engineering, drug release kinetic, bioactivity, cell proliferation, differentiation, and animal study were conducted. Our findings illustrate that utilization of mesoporous calcium silicate allowed the introduction of fibroblast growth factor-2 into the composite scaffolds through a simple soaking process and then gradually released from the scaffold to facilitate proliferation and osteogenesis differentiation of human Wharton’s jelly mesenchymal stem cells. Additionally, the in vivo femur defect experiments also indicate that the co-existence of calcium silicate and fibrous growth factor-2 synergistically accelerated new bone formation. These results demonstrate that the fibroblast growth factor-2-loaded mesoporous calcium silicate nanoparticles/polycaprolactone composite scaffolds may serve as potential bone grafts for facilitating repair of defected bone tissues.

Surfactin as a Green Agent Controlling the Growth of Porous Calcite Microstructures.

This study presents a new, simple way to obtain mesoporous calcite structures via a green method using an eco-friendly surface-active compound, surfactin, as a controlling agent. The effects of synthesis time and surfactin concentration were investigated. The obtained structures were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) coupled with gas mass spectrometry (QMS) analysis. The experimental data showed that surfactin molecules significantly changed the morphology of the calcite crystals, roughening and deforming the surface and creating a greater specific surface area, even at low biosurfactant concentrations (10 ppm). The size of the crystals was reduced, and the zeta potential value of calcium carbonate was more negative when more biosurfactant was added. The XRD data revealed that the biomolecules were incorporated into the crystals and slowed the transformation of vaterite into calcite. It has been shown that as long as vaterite is present in the medium, the calcite surface will be less deformed. The strong influence of surfactin molecules on the crystal growth of calcium carbonate was due to the interaction of surfactin molecules with free calcium ions in the solution as well as the biomolecules adsorption at the formed crystal surface. The role of micelles in crystal growth was examined, and the mechanism of mesoporous calcium carbonate formation was presented.

Experimental and theoretical studies on the removal mechanism of formaldehyde from water by mesoporous calcium silicate

Most porous materials with high specific surface area and diverse internal structures possess good adsorption ability. In this work, a tremella-like mesoporous calcium silicate hydrate (CSH) with high adsorption capacity was successfully prepared via a facile hydrothermal method. The adsorption effect and adsorption mechanism of the as-prepared calcium silicate hydrate (AP-CSH) towards formaldehyde from water were investigated systematically. Results indicate that AP-CSH has high Ca/Si ratio (1.95), large specific surface area (122.83 m2 g−1) and exhibits excellent adsorption capacity. The results of batch adsorption experiments show that AP-CSH can remove formaldehyde from water rapidly and effectively with the maximum removal efficiency of 98.94%. The adsorption process agrees well with the pseudo-second-order and Freundlich isotherm model. Furthermore, regeneration can be achieved by simply immersing AP-CSH in absolute ethanol and the removal efficiency can still reach about 99.50% after five cycles. The adsorption mechanism was also studied by experimental analyses and molecular dynamics simulation. Both experimental results and theoretical simulation support that formaldehyde adsorption over AP-CSH belongs to chemical adsorption.

Mesoporous particles for transdermal delivery of the antifungal drug griseofulvin

Griseofulvin is an antifungal antibiotic applying for the treatment of dermatophyte infections. The most common delivery route of this drug is oral. The dosage of griseofulvin varies depending on whether the drug is administered as a microsized or an ultramicrosized preparation. In order to avoid possible incidental systemic toxicity associated with the oral delivery route and reduce the therapeutic dose, a novel approach for the griseofulvin administration is proposed. Immobilization of the drug into mesoporous calcium carbonate particles together with their further ultrasonically-assisted topical application provides the efficient transdermal transportation. Accumulation of griseofulvin-loaded carriers inside hair follicles of the rat is demonstrated in vivo, allowing by this means the targeted delivery of the antifungal drug to the lesion area of skin. No significant toxicity of the system is shown for rat and human fibroblasts cells in vitro.

Osteopontin sequence modified mesoporous calcium silicate scaffolds to promote angiogenesis in bone tissue regeneration.

Sufficient blood supply remains the key issue to be addressed for an optimal performance of implanted bone tissue engineering scaffolds. Host vessel invasion is limited to a depth of only several hundred micrometers from the scaffold/host interface. In this study, an osteopontin sequenced polypeptide SVVYGLR was grafted into/onto mesoporous calcium silicate (MCS) and then 3D-printed into scaffolds. The peptide motifs can be accessed on the scaffold surfaces and released as well. In vitro studies of human umbilical vein endothelial cells (HUVECs) indicated enhanced cell adhesion and vascular-like structure formation on MCS-SVVYGLR scaffolds. At the same time, human bone marrow stromal cells (hBMSCs) showed enhanced osteogenic differentiation capability and higher expression levels of angiogenic genes and proteins as well. The results of in vivo radial defect repair tests of rabbits showed that more tubular vessels formed throughout the whole MCS-SVVYGLR scaffolds, and therefore, a more homogeneous new bone formation pattern was obtained on MCS-SVVYGLR scaffolds instead of a peripheral bone growth pattern on pure MCS scaffolds by Micro-CT and tissue staining techniques over 3 months. Relative gene and protein expressions in PI3K/AKT and ERK1/2 pathways suggested that the SVVYGLR motif on the MCS scaffold surface could initiate the PI3K/AKT signaling pathway and up-regulate ERK1/2 expression, which positively stimulated VEGF expression, to improve angiogenesis.

Synthesis of mesoporous calcium titanate catalyst for transesterification of used cooking oil: A review of the synthesized potential

Synthesis of mesoporous calcium titanate catalyst for transesterification of used cooking oil: A review of the synthesized potential

Investigation of new routes for the preparation of mesoporous calcium oxide supported nickel materials used as catalysts for the methane dry reforming reaction

Calcium oxide mesoporous supports were successfully synthetized and used to disperse nickel nanoparticles for the dry reforming of methane catalytic reaction.

Water-assisted synthesis of mesoporous calcium carbonate with a controlled specific surface area and its potential to ferulic acid release.

A carbonation process to control the specific surface area of mesoporous calcium carbonate and the dissolution profile of ferulic acid on mesoporous carbonate particles are presented. The effects of water content on the physicochemical properties, specific surface area, pore size, crystallinity, and morphology are evaluated. Mesoporous calcium carbonate particles are synthesised with well-controlled specific surface areas of 38.8 to 234 m2 g−1. Each of the submicron-size secondary particles consists of a primary particle of nano-size. During secondary particle formation, primary particle growth is curbed in the case with less water content. By contrast, growth is promoted via dissolution and recrystallisation in the presence of water. The release rates of ferulic acid are gradually enhanced with increasing specific surface area of the mesoporous calcium carbonate, that reflects crystallinity of ferulic acid.

Surface charge of mesoporous calcium silicate and its adsorption characteristics for heavy metal ions

Mesoporous calcium silicate (MCS) was synthesized using the ultrasonic-assisted template method by using calcium nitrate tetrahydrate and sodium metasilicate nonahydrate as raw materials and cetyltrimethylammonium bromide–methenamine as the template. X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and Brunauer–Emmett–Teller method were used for the characterization of MCS. The surface charge characteristics of MCS and its adsorption characteristics for Ni2+, Cu2+, Zn2+, Pb2+, Mn2+, and Cd2+ were also investigated. MCS formed through the accumulation of thin flakes with various shapes and exhibited a slit-pore structure and uneven surfaces with a specific surface area of 239.41 m2 g−1 and a pore size of 11.74 nm. MCS possessed a distinct, wide, near-zero potential point pH range of 5–9, and the point of zero charge, pHPZC, reached 8.6 ± 0.1. The MCS surface was alkaline, and MCS exhibited excellent acid–base buffering capacity at pH 5–11. The high adsorption capacity of MCS for the six heavy metal ions at pH 5.0–7.5 followed the order Pb2+ > Cd2+ > Zn2+ > Cu2+ > Ni2+ > Mn2+ (in mgg−1). The adsorption for the six heavy metal ions occurred rapidly and attained equilibrium within 120 min. The order of adsorption activation energy was Mn2+ > Zn2+> Ni2+ > Pb2+ > Cu2+ > Cd2+. The adsorption processes of the six heavy metal ions were all endothermic, entropy increasing, and spontaneous. MCS remained stable during adsorption, but the adsorbed heavy metal ions underwent transformation, especially Cu2+, Pb2+, and Cd2+, which formed new phases. The adsorption mechanisms included physical adsorption, chemical adsorption (particularly surface complexing adsorption and surface precipitation), and ion exchange. MCS exhibits an excellent adsorption and recycling performance and the potential to become an adsorption material with excellent properties for heavy metal ions.

Metal-Loaded Carbonated Mesoporous Calcium Silicates: Synthesis, Characterization, and Application for Diclofenac Removal from Water

In this study, we developed a simple synthesis method of carbonated mesoporous calcium silicate (MCS) materials loaded with iron (Fe–MCS), cerium (Ce–MCS), and iron and cerium (FeCe–MCS) using cety...

Gadolinium-doped mesoporous calcium silicate/chitosan scaffolds enhanced bone regeneration ability.

Chitosan (CTS) and mesoporous calcium silicate (MCS) have been developed for bone defect healing; however, their bone regeneration capacity still does not satisfy the patients with bone diseases. Gadolinium (Gd) is accumulated in human bones, and plays a beneficial role in regulating cell performance and bone regeneration. We firstly constructed Gd-doped MCS/CTS (Gd-MCS/CTS) scaffolds by a lyophilization technology. The interconnected arrangement of CTS films lead to forming macropores by using ice crystals as templates during the lyophilization procedure, and the Gd-MCS nanoparticles dispersed uniformly on the macropore walls. The biocompatible chemical components and hierarchical pores facilitated the attachment and spreading of rat bone marrow-derived mesenchymal stem cells (rBMSCs). Interestingly, the Gd dopants in the scaffolds effectively activated the Wnt/β-catenin signaling pathway, resulting in excellent cell proliferation and osteogenic differentiation capacities. The osteogenic-related genes such as alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2) and collagen type1 (COL-1) were remarkably up-regulated by Gd-MCS scaffolds as compared with MCS scaffolds, and their expression levels increased in a positive correlation with Gd doping amounts. Moreover, in vivo rat cranial defect tests further confirmed that Gd-MCS/CTS scaffolds significantly stimulated collagen deposition and new bone formation. The exciting finding suggested the beneficial effects of Gd3+ ions on osteogenic differentiation and new bone regeneration, and Gd-MCS/CTS scaffolds can be employed as a novel platform for bone defect healing.

Template-Free Synthesis and Properties of Mesoporous Calcium Titanate

X-ray amorphous powder was obtained via template-free synthesis, including the sol–gel process and coprecipitation. We showed that mesoporous calcium titanate is formed during the calcination of a powder up to 800°C. The structure and morphology of the samples thermally processed at 200, 400, 600, and 800°C are studied with scanning electron microscopy, X-ray phase analysis, thermogravimetric analysis, and IR spectroscopy. Low-temperature adsorption–desorption of nitrogen vapors and laser diffraction analysis showed that calcium titanate powder has a highly developed surface of over 100 m2/g with average particle size from 99 to 290 nm and significant pore volume.

Alternative green preparation of mesoporous calcium hydroxyapatite by chemical reaction of eggshell and phosphoric acid

AbstractEggshell is a rich source of CaCO3 with a high purity content of more than 96.35% w/w and a potential raw material for calcium hydroxyapatite preparation. Mesoporous and nano‐particulate calcium hydroxyapatite was prepared from duck eggshell from the chemical reaction with phosphoric acid followed by the calcinations at 800, 900, and 1000°C for 2 hours. The optimum condition to obtain the high purity calcium hydroxyapatite was by sintering calcium phosphate Ca3(PO4)2 at 1000°C for 2 hours. The average particle size, pore diameter, specific surface, and true density of the sample sintered at 1000°C for 2 hours were 101.93 ± 12.15 nm, 98.96 Å, 2.12 m2/g, and 3.02 g/cm3, respectively, appearing as a soft fine powder with a white color. The raw duck eggshell is a potential candidate as a bio‐ceramic material to prepare calcium hydroxyapatite suitable for use in various bio‐applications such as bone tissue engineering, drug and gene delivery, remineralizing agent in toothpaste, and bone void fillers for orthopedic and restoration.

Mesoporous carriers for transdermal delivery of antifungal drug

Immobilization of antifungal drugs into various nano- and submicron carriers is a perspective way to overcome such limitations associated with their application as high toxicity and unfavorable physicochemical properties. The current study introduces a novel formulation for the poor soluble antimicotic drug. Griseofulvin, which is based on mesoporous calcium carbonate particles offering enhanced loading capacity and bioavailability. Proposed particulate system provides delivery and accumulation into the skin that reveals promising outlook for topical antifungal treatment providing targeted delivery to the lesion area of skin.

Erlotinib-Valproic Acid Liquisolid Formulation: Evaluating Oral Bioavailability and Cytotoxicity in Erlotinib-Resistant Non-small Cell Lung Cancer Cells.

Lung cancer patients develop acquired resistance to tyrosine kinase inhibitors including erlotinib (ERL) after few months of primary treatment. Evidently, new chemotherapy strategies to delay or overcome the resistance are urgently needed to improve the clinical outcome in non-small cell lung cancer (NSCLC) patients. In this paper, we have investigated the cytotoxic interaction of ERL and valproic acid (VA) in ERL-resistant NSCLC cells and developed a liquisolid formulation of ERL-VA for improving oral bioavailability of ERL. ERL is weakly basic, biopharmaceutical classification system (BCS) class II drug with extremely poor aqueous solubility while VA is a branched chain fatty acid. Ionic interaction between ERL and VA (1:2M ratio) resulted in significant enhancement in saturation solubility of ERL at different pH range. Liquisolid formulation of ERL-VA (EVLF) developed using PEG 400 and mesoporous calcium silicate was characterized for solid state and in vitro dissolution in biorelevant dissolution medium (FaSSIF and FeSSIF). Cytotoxicity of ERL was enhanced by 2-5 folds on co-incubation with VA in HCC827/ERL cell line. Flow cytometry analysis using AnnexinV-FITC assay demonstrated that VA and ERL alone have poor apoptotic effect on HCC827/ERL cells while combination showed around 69% apoptotic cells. Western blot analysis confirmed the role of survivin in overcoming resistance. In vivo pharmacokinetic studies of EVLF in rats demonstrated a 199% relative bioavailability compared to ERL suspension. Thus, EVLF could be a promising alternative to current ERL formulations in the treatment of NSCLC.

Comparison of 3D-printed mesoporous calcium silicate/polycaprolactone and mesoporous Bioacive glass/polycaprolactone scaffolds for bone regeneration

Abstract Mesoporous calcium silicate (MCS) and mesoporeous bioactive glass (MBG) are important components of silicon-based bioceramics and have been widely investigated. However, few studies were specifically focused on the differences between MCS and MBG scaffolds for bone regeneration application. In this work, we 3D printed MCS/PCL and MBG/PCL scaffolds with highly similar inter-structure and mechanical preperties. And human bone marrow mesenchymal stem cells (hBMSCs) were used to evaluate the bioactivity and biocompatibility of that two scaffolds. After soaked in simulated body fluid (SBF) for 3 days, both MCS/PCL and MBG/PCL scaffolds showed good mineralization. Although there was no statistical difference hBMSCs proliferation on these scaffolds, MBG/PCL scaffolds showed better capacity of improving ALP activity of hBMSCs than MCS/PCL scaffolds. Moreover, MBG/PCL scaffolds significantly enhanced the osteogenic-related gene expressions, such as osteocalcin (OCN), bone morphgenetic protein-2 (BMP-2), collagen type I (COL-1), bone sialoprotein (BSP), runt-related transcription factor 2 (RUNX2), and bone sialoprotein (BSP). Together, the results indicate that MBG/PCL scaffolds are promising implants for bone regeneration application.

La-Doped mesoporous calcium silicate/chitosan scaffolds for bone tissue engineering.

Trace rare earth elements such as lanthanum (La) regulated effectively bone tissue performances; however, the underlying mechanism remains unknown. In order to accelerate bone defects especially in patients with osteoporosis or other metabolic diseases, we firstly constructed lanthanum-doped mesoporous calcium silicate/chitosan (La-MCS/CTS) scaffolds by freeze-drying technology. During the freeze-drying procedure, three-dimensional macropores were produced within the La-MCS/CTS scaffolds by using ice crystals as templates, and the La-MCS nanoparticles were distributed on the macropore walls. The hierarchically porous structures and biocompatible components contributed to the adhesion, spreading and proliferation of rat bone marrow-derived mesenchymal stem cells (rBMSCs), and accelerated the in-growth of new bone tissues. Particularly, the La3+ ions in the bone scaffolds remarkably induced the osteogenic differentiation of rBMSCs via the activation of the TGF signal pathway. A critical-sized calvarial-defect rat model further revealed that the La-MCS/CTS scaffolds significantly promoted new bone regeneration as compared with pure MCS/CTS scaffolds. In conclusion, the La-MCS/CTS scaffold showed the prominent ability in osteogenesis and bone regeneration, which showed its application potential for bone defect therapy.

Purification of ricinoleic acid methyl ester using mesoporous calcium silicate (CaSiO3) adsorben

Ricinoleic acid methyl ester has been purified from a mixture of fatty acid methyl esters resulted fron transesterification of castor oil using a 200 mesh mesoporous calcium silicate adsorbent. The purity of ricinoleic acid methyl ester was increased from 48% to 94% conformed by gas chromatography. It is proposed that in adsorption process, a strong interaction between calcium silicate and ricinoleic acid methyl ester occurs through empty d-orbital of Ca-atom of calcium silicate and O-atom of the hydroxyl group of ricinoleic acid methyl ester. The resulting ricinoleic acid methyl ester was confirmed by 1H-NMR and 13C-NMR.

Conventional and microwave synthesis of mesoporous calcium titanate nanopowders: a comparative study

CaTiO3 nanopowders having mesoporous structure were synthesized in different heating environments. Thermal decomposition of intermediate phases was observed as a primary mechanism behind formation of high-purity CaTiO3 nanopowders. Overall analysis of results suggested that different heating environments exhibited significant implications on particle size, porosity, and pore distribution properties of CaTiO3 nanopowders.

Enhanced Capability of Bone Morphogenetic Protein 2–loaded Mesoporous Calcium Silicate Scaffolds to Induce Odontogenic Differentiation of Human Dental Pulp Cells

IntroductionCalcium silicate bioceramics have been broadly used as reparative or grafting materials with good bioactivity and biocompatibility in dental application. It has been shown that applying a mesoporous process to calcium silicate gives it great potential as a controlled drug delivery system. MethodsThe aim of this study was to investigate a novel osteoinductive scaffold by loading bone morphogenetic protein 2 (BMP-2) to mesoporous calcium silicate (MesoCS) and fabricating it as 3-dimensional scaffolds using fused deposition modeling combined with polycaprolactone. ResultsThe MesoCS/BMP-2 scaffold showed similar patterns to that of a calcium silicate scaffold in releasing calcium and silicon ions in a simulated body fluid (SBF) immersion test for 7 days, but BMP-2 continued releasing from the MesoCS/BMP-2 scaffold significantly more than the CS scaffold from 48 hours to 7 days. Adhesion and proliferation of human dental pulp cells cultured on a MesoCS/BMP-2 scaffold were also more significant than scaffolds without BMP-2 or mesoporous as well as the results of the test on alkaline phosphatase activity. ConclusionsThe results support that the novel 3-dimensional–printed MesoCS scaffold performed well as BMP-2 delivery system and would be an ideal odontoinductive biomaterial in regenerative endodontics.