Fabrication and Characterization of Strontium-Substituted Hydroxyapatite-CaO-CaCO3 Nanofibers with a Mesoporous Structure as Drug Delivery Carriers

Hydroxyapatite (HAp) is the main inorganic component and an essential part of hard bone and teeth. Due to its excellent biocompatibility, bioactivity, and osteoconductivity, synthetic HAp has been widely used as a bone substitute, cell carrier, and therapeutic gene or drug carrier. Recently, numerous studies have demonstrated that strontium-substituted hydroxyapatite (SrHAp) not only enhances osteogenesis but also inhibits adipogenesis in mesenchymal stem cells. Mesoporous SrHAp has been successfully synthesized via a traditional template-based process and has been found to possess better drug loading and release efficiencies than SrHAp. In this study, strontium-substituted hydroxyapatite-CaO-CaCO3 nanofibers with a mesoporous structure (mSrHANFs) were fabricated using a sol–gel method followed by electrospinning. X-ray diffraction analysis revealed that the contents of CaO and CaCO3 in the mSrHANFs decreased as the doping amount of Sr increased. Scanning electron microscopy (SEM) images showed that the average diameter of the mSrHANFs was approximately 200~300 nm. The N2 adsorption–desorption isotherms demonstrated that the mSrHANFs possessed a mesoporous structure and that the average pore size was approximately 20~25 nm. Moreover, the mSrHANFs had excellent drug- loading efficiency and could retard the burst release of tetracycline (TC) to maintain antibacterial activity for over 3 weeks. Hence, mSrHANFs have the potential to be used as drug carriers in bone tissue engineering.

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Synthesis and Characterization of TiO2-CaO and TiO2-CaO-Fe2O3 Photocatalyst for Removal of Catechol

Molekul ◽

10.20884/1.jm.2019.14.2.570 ◽

2019 ◽

Vol 14 (2) ◽

pp. 140

Author(s):

Candra Yulius Tahya ◽

Wahyu Irawati ◽

Karnelasatri Karnelasatri ◽

Friska Juliana Purba

Keyword(s):

Surface Area ◽

Adsorption Property ◽

Average Pore Size ◽

Sol Gel ◽

Bet Surface Area ◽

Sem Images ◽

Average Pore ◽

Xrd Pattern ◽

Two Peaks

TiO2-CaO and TiO2-CaO-Fe2O3 photocatalysts have been synthesized through the surfactant-assisted sol-gel method. The catalysts were characterized using XRD, FTIR, SEM-ED Sand BET surface area. XRD pattern showed the formation of anatase TiO2 crystal phase both in TiO2-CaO and TiO2-CaO-Fe2O3. The TiO2-CaO has higher crystallinity than TiO2-CaO-Fe2O3. Based on the peak refinement using Rietveld, there are two peaks identified as Fe2O3 hematite in the sample TiO2-CaO-Fe2O3. BET surface area analysis showed that the average pore size of TiO2-CaO and TiO2-CaO-Fe2O3 catalysts are 8.04 and 8.41 nm respectively, indicating both catalysts are mesoporous.FTIR spectra show that the vibration of Ti-O, Ca-O, and Ca-TiO2 were observed in both catalysts. SEM images confirm that both catalysts are porous material. The catechol removal using TiO2-CaO and TiO2-CaO-Fe2O3 improved with the increase of catalyst concentration. After 360 minutes of UV radiation, the removal of catechol using TiO2-CaO-Fe2O3 reached 46.0%, 48.3%, and 69.2%, while when using TiO2-CaO, it reached 22.1%, 36.8%, and 57.0% for 0.1 g, 0.15 g, and 0.2 g of catalysts, respectively. The photocatalytic activity of TiO2-CaO-Fe2O3 is not so strong compared to TiO2-CaO catalyst but the catechol adsorption property of TiO2-CaO-Fe2O3 is higher than that of TiO2-CaO catalyst.

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Bioactive ceramic powder prepared using a new sol-gel process

Processing and Application of Ceramics ◽

10.2298/pac1702087b ◽

2017 ◽

Vol 11 (2) ◽

pp. 87-92 ◽

Cited By ~ 2

Author(s):

Vương Bùi

Keyword(s):

Average Pore Size ◽

Sol Gel ◽

Ceramic Powder ◽

Nitrogen Adsorption ◽

Mesoporous Structure ◽

Average Pore ◽

Vitro Assay ◽

Sol Gel Process ◽

Bioactive Ceramic

Bioactive ceramic powder containing 45% SiO2, 24.5% CaO, 24.5% Na2O and 6% P2O5 (wt.%) was synthesized using a new sol-gel process. The preparedmaterial was investigated by several physico-chemical methods. The X-ray diffraction showed the presence of two crystalline phases, Na6Ca3Si6O18 and NaCaPO4. The high specific surface area (47m2/g) and a mesoporous structure with the average pore size of 2.6 nm were confirmed using low-temperature nitrogen adsorption technique. In vitro experiments were carried out by soaking the powder sample in simulated body fluid (SBF) at different times. XRD, FTIR and SEM coupled with EDS were used for in vitro evaluation of bioactivity. The obtained results confirmed that the ceramic powder can be used as biomaterial for bone tissue engineering due to its high bioactivity expressed by the rapid formation of a biological carbonated hydroxyapatite layer on its surface after in vitro assay.

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Spray-Dried Quercetin-Lactose Powders for Oral Tablets with Improved Dissolution Rates and Modified Material Properties

Journal of Nanomaterials ◽

10.1155/2021/2365353 ◽

2021 ◽

Vol 2021 ◽

pp. 1-6

Author(s):

Long Li ◽

Yuanwei Li ◽

Zhiying Wu ◽

Jinhui Chen ◽

Jia Chen

Keyword(s):

Spray Drying ◽

Drug Carrier ◽

Average Pore Size ◽

Mesoporous Structure ◽

Exothermic Peak ◽

Hot Water ◽

Raw Material ◽

Drying Method ◽

Average Pore ◽

Spray Dried

This study is aimed at using spray drying method to codisperse it with the commonly used drug carrier lactose in different solvents and then pass it through a spray dryer to obtain different samples. The results showed that the dissolution rate and solubility of the samples obtained by dispersion in hot water and 25% ethanol were significantly higher. The water of crystallization peaks of the raw material disappeared at 105-125°C and 130-150°C (DSC). The excipient lactose had a small upward exothermic peak at 177°C and a significant heat absorption peak at 209°C before untreated (XRD). α-Lactose peaks were observed at 12.5°, 19.1°, 19.6°, and 19.9° at 2θ in both samples, and β-lactose peaks were found at 10.5° at 2θ in sample A, but not in sample B (FTIR). The complex sharp peaks of lactose at 1100 cm-1 and quercetin at 1700-1000 cm-1 became moderated (SEM). The sample obtained by spray drying has a slit-type mesoporous structure with an average pore size of about 9.3 nm.

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Stereocomplexation Assisted Assembly of Poly(γ-glutamic Acid)-graft-polylactide Nano-micelles and Their Efficacy as Anticancer Drug Carrier

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520617666170911170104 ◽

2018 ◽

Vol 18 (2) ◽

pp. 302-311

Author(s):

Shulin Dai ◽

Yucheng Feng ◽

Shuyi Li ◽

Yuxiao Chen ◽

Meiqing Liu ◽

...

Keyword(s):

Glutamic Acid ◽

Drug Carrier ◽

Drug Loading ◽

Drug Carriers ◽

Cancer Drug ◽

Drug Release Profile ◽

Sustained Drug Release ◽

Anti Cancer ◽

Physical Interactions

Background: Micelles as drug carriers are characterized by their inherent instability due to the weak physical interactions that facilitate the self-assembly of amphiphilic block copolymers. As one of the strong physical interactions, the stereocomplexation between the equal molar of enantiomeric polylactides, i.e., the poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA), may be harnessed to obtain micelles with enhanced stability and drug loading capacity and consequent sustained release. </P><P> Aims/Methods: In this paper, stereocomplexed micelles gama-PGA-g-PLA micelles) were fabricated from the stereocomplexation between poly(gama-glutamic acid)-graft-PLLA gama-PGA-g-PLA) and poly(gamaglutamic acid)-graft-PDLA gama-PGA-g-PLA). These stereocomplexed micelles exhibited a lower CMC than the corresponding enantiomeric micelles. Result: Furthermore, they showed higher drug loading content and drug loading efficiency in addition to more sustained drug release profile in vitro. In vivo imaging confirmed that the DiR-encapsulated stereocomplexed gama-PGA-g-PLA micelles can deliver anti-cancer drug to tumors with enhanced tissue penetration. Overall, gama-PGA-g-PLA micelles exhibited greater anti-cancer effects as compared with the free drug and the stereocomplexation may be a promising strategy for fabrication of anti-cancer drug carriers with significantly enhanced efficacy.

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Silica Sol-Gel Supported Nickel Nano-Catalyst for Hydrogen Production Using Microreactors

MRS Proceedings ◽

10.1557/proc-0885-a10-09 ◽

2005 ◽

Vol 885 ◽

Author(s):

Krithi Shetty ◽

Shihuai Zhao ◽

Wei Cao ◽

Naidu V. Seetala ◽

Debasish Kuila

Keyword(s):

Steam Reforming ◽

Average Pore Size ◽

Sol Gel ◽

Supported Catalyst ◽

Silica Sol ◽

Average Pore ◽

Steam Reforming Of Methanol ◽

Nano Catalyst ◽

Before And After ◽

Reforming Reactions

ABSTRACTThe goal of this research is to investigate the activities of a non-noble nano-catalyst (Ni/SiO2) using Si-microreactors for steam reforming of methanol to produce hydrogen for fuel cells. The supported catalyst was synthesized by sol-gel method using Ni (II) salts and Si(C2H5O)4 as starting materials. EDX results indicate that the actual loading of Ni (5-6%) is lower than the intended loading of 12 %. The specific surface area of the silica sol-gel encapsulated Ni nano-catalyst is 452 m2/g with an average pore size of ∼ 3 nm. Steam reforming reactions have been carried out in a microreactor with 50 µm channels in the temperature range of 180-240 °C and atmospheric pressure. Results show 53% conversion of methanol with a selectivity of 74 % to hydrogen at 5 l/min and 200 °C. The magnetic properties of the catalysts were performed using a Vibrating Sample Magnetometer (VSM) to study the activity of the catalysts before and after the steam reforming reactions. The VSM results indicate much higher activity in the microreactor compared to macro-reactor and Ni forms non-ferromagnetic species faster in the microreactor.

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Sol-Gel Derived Silica Layers for Low-k Dielectrics Applications

MRS Proceedings ◽

10.1557/proc-612-d5.26.1 ◽

2000 ◽

Vol 612 ◽

Cited By ~ 4

Author(s):

Sylvie Acosta ◽

André Ayral ◽

Christian Guizard ◽

Charles Lecornec ◽

Gérard Passemard ◽

...

Keyword(s):

Average Pore Size ◽

Sol Gel ◽

Porous Silica ◽

Thin Layers ◽

Gaseous Ammonia ◽

Potential Candidate ◽

Average Pore ◽

Synthesis Strategy ◽

Silica Layers ◽

Highly Porous

AbstractPorous silica exhibits attractive dielectric properties, which make it a potential candidate for use as insulator into interconnect structures. A new way of preparation of highly porous silica layers by the sol-gel route was investigated and is presented. The synthesis strategy was based on the use of common and low toxicity reagents and on the development of a simple process without gaseous ammonia post-treatment or supercritical drying step. Defect free layers were deposited by spin coating on 200 mm silicon wafers and characterized. Thin layers with a total porosity larger than 70% and an average pore size of 5 nm were produced. The dielectric constant measured under nitrogen flow on these highly porous layers is equal to ∼ 2.5, which can be compared to the value calculated from the measured porosity, ∼ 1.9. This difference is explained by the presence of water adsorbed on the hydrophilic surface of the unmodified silica.

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Synthesis, characterization, and photocatalytic activity of silver and zinc co-doped TiO2 nanoparticle for photodegradation of methyl orange dye in aqueous solution

Canadian Journal of Chemistry ◽

10.1139/cjc-2018-0308 ◽

2019 ◽

Vol 97 (9) ◽

pp. 642-650 ◽

Cited By ~ 5

Author(s):

Gabriel O. Oladipo ◽

Akinola K. Akinlabi ◽

Samson O. Alayande ◽

Titus A.M. Msagati ◽

Hlengilizwe H. Nyoni ◽

...

Keyword(s):

Methyl Orange ◽

Pore Size ◽

Average Pore Size ◽

Sol Gel ◽

Average Crystallite Size ◽

Rutile Phase ◽

Absorption Bands ◽

Average Pore ◽

Methyl Orange Dye ◽

Co Doped

In this study, TiO2 nanocrystals, 1 mol% Ag-doped TiO2, and 1 mol% Ag and 0.6 mol% Zn co-doped TiO2 powders were synthesized by the sol–gel route. Their photocatalytic activities on methyl orange dye under visible irradiation were investigated. The powders were characterized by X-ray diffraction (XRD), UV–visible spectroscopy (UV–vis), Brunauer–Emmett–Teller (BET), and Fourier transform infrared spectroscopy (FTIR). The XRD results revealed the presence of a rutile phase with an average crystallite size of 9 and 11 nm. The UV–vis spectra showed a red-shift towards a longer wavelength with the corresponding decrease in band gap from 2.9 to 2.5 eV. The BET surface areas of the nanoparticles ranged from 4.7 to 11.8 m2 g−1 with an average pore size between 18.9 and 56.6 nm. The Ag-doped TiO2 has the largest surface area of 11.8 m2 g−1, whereas the Ag–Zn co-doped TiO2 was found to have the highest pore size and volume. The absorption bands at 750–500 cm−1 were attributed to the –O–Ti–O– bond in the TiO2 lattice. The photocatalytic efficiency was highest at an optimum pH of 4.1 for Ag–Zn co-doped TiO2. The results confirmed that Ag-doped and Ag–Zn co-doped TiO2 were more effective than pure TiO2. The kinetic data were fitted into a pseudo first-order equation using a Langmuir–Hinshelwood kinetic model.

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Collagen Scaffolds Containing Hydroxyapatite-CaO Fiber Fragments for Bone Tissue Engineering

Polymers ◽

10.3390/polym12051174 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1174 ◽

Cited By ~ 1

Author(s):

Shiao-Wen Tsai ◽

Sheng-Siang Huang ◽

Wen-Xin Yu ◽

Yu-Wei Hsu ◽

Fu-Yin Hsu

Keyword(s):

Tissue Engineering ◽

Bone Tissue Engineering ◽

Bone Regeneration ◽

Bone Tissue ◽

Drug Loading ◽

Sol Gel ◽

Regeneration Ability ◽

Burst Release ◽

Electrospinning Technique

Collagen (COL) and hydroxyapatite (HAp) are the major components of bone, therefore, COL-HAp composites have been widely used as bone substitutes to promote bone regeneration. We have reported that HAp-CaO fibers (HANFs), which were fabricated by a sol-gel route followed by an electrospinning technique, possessed good drug-loading efficiency and limited the burst release of tetracycline. In the present study, we used HANF fragments to evaluate the effects of COL-HANF scaffolds on MG63 osteoblast-like cell behaviors. COL-HANF composite scaffolds in which the average diameter of HANFs was approximately 461 ± 186 nm were fabricated by a freeze-drying process. The alkaline phosphatase activity and the protein expression levels of OCN and BSP showed that compared with COL alone, the COL-HANF scaffold promoted the differentiation of MG63 osteoblast-like cells. In addition, the bone regeneration ability of the COL-HANF scaffold was examined by using a rabbit condylar defect model in vivo. The COL-HANF scaffold was biodegradable and promoted bone regeneration eight weeks after the operation. Hence, we concluded that the COL-HANF scaffold has potential as a bone graft for bone tissue engineering.

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Optimization of Preparation Conditions of Crosslinked Potato Starch Microsphere through Orthogonal Experimental Design

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.524-527.2188 ◽

2012 ◽

Vol 524-527 ◽

pp. 2188-2198

Author(s):

Bo Zhang ◽

Shun Yu Han ◽

Yu Sen Hu ◽

Lu Mei Pu ◽

Wen Ying Wang

Keyword(s):

Water Solution ◽

Potato Starch ◽

Drug Carrier ◽

Drug Loading ◽

Base Material ◽

Drug Carriers ◽

Orthogonal Experimental Design ◽

Starch Gelatinization ◽

Starch Microsphere ◽

Water Ph

A lot of studies were done on the base material of drug carriers: liposome, protein microsphere, glutin and high polymer microsphere were all of shortages, but starch has much superiority as the drug carrier. The paper embarked from the analysis the chemical and physical properties of potato starch. According as the characteristic of long chain molecules of potato starch forming microcrystal bundle via inter-molecules hydrogen association under room temperature, which disintegrated in water solution as temperature rising, the better levels of factors, such as gelatinization temperature, gelatinization time, volume of water, pH, according to viscosity of starch gelatinization were select firstly. A W/O reverse emulsion was obtained by dispersing the starch gelatinization into the oil. The effect of emulsifier, evocating agent, crosslinker, crosslinking temperature, and crosslinking time was investigated. An orthogonal experiment of L27(313) was designed to identify the main factors affecting them. In light of range analysis, the comparative importance of factors impacting drug loading was obtained, separately. The effects of parameters were studied using analysis of variance. The results showed that the effective factor to control drug loading were the amount of starch, the volume of water, pH, crosslinking time and the amount of evocating agent, whereas the influences of other factors on drug loading were not significant. In addition, the structure of N, N-Methylenebisacrylamide (MBAA) crosslinked potato starch microsphere (CPSM) was characterized by Fourier transform infrared (FTIR) spectrophotometer and Scanning electron microscope (SEM).

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Porous TiO2-Al2O3 Photocatalyst: The Effects of Calcination Time

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.496.165 ◽

2012 ◽

Vol 496 ◽

pp. 165-168 ◽

Cited By ~ 2

Author(s):

Wen Jie Zhang ◽

Hong Liang Xin

Keyword(s):

Composite Materials ◽

Average Pore Size ◽

Sol Gel ◽

Specific Area ◽

Maximum Activity ◽

Calcination Time ◽

Average Pore ◽

Porous Tio2 ◽

Al2o3 Composite ◽

Ft Ir

Porous TiO2-Al2O3 composite materials were prepared through sol-gel method after calcination at 500 oC for different time. FT-IR spectra of porous TiO2-Al2O3 composite materials revealed that the samples are composed of Al2O3 and TiO2. The sample calcinated for 2.5 h had the maximum specific area of 128.9 m2•g-1. High pore volume and average pore size were possessed by the samples calcinated for 1 h and 3 h. While being calcinated at 500 oC, photocatalytic activities of the materials increased at first and then dropped down with the increasing calcination time. The sample calcinated for 3 h showed the maximum activity of 35%.

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