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1.
BMC Geriatr ; 24(1): 464, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38802798

RESUMO

BACKGROUND: The population is rapidly aging and remains active over the age of 65 years. An increasing number of sports-related fractures (SRFs) in individuals 65 and older are thus anticipated. Despite the increase in SRFs among the geriatric population, there are limited studies regarding the epidemiological data regarding SRFs in geriatric patients. This study examined the epidemiology of SRFs in a geriatric population who visited a level I trauma center. METHODS: Data from geriatric patients who visited a level I trauma center were collected between June 2020 and July 2023. Overall, 1,109 geriatric patients with fractures were included in the study. Among them, 144 (13.0%) had fractures during sports activities (SRF group) and 965 (87.0%) had fractures during non-sports activities (non-SRF group). We investigated the type of sport in the SRFs and compared SRFs and NSRFs to describe the differences in patient, fracture, and treatment characteristics. RESULTS: The mean age of SRFs was significantly lower (73.6 vs. 78.7 years; P < .001). The proportion of men was significantly higher in the SRF group than in the non-SRF group (51.4 vs. 29.6%; P < .001). We identified 13 types of sports associated with fractures, and the four most common were outdoor walking (36.1%), outdoor biking (27.8%), mountain hiking (19.4%), and gym (8.3%). There were no significant differences in the rate of hospitalization, operative treatment, or length of hospital stay between the two groups. However, compared to the non-SRF group, patients in the SRF group tended to return home after hospitalization (P = .002). CONCLUSION: This epidemiological study describes geriatric population that continues to be involved in sports and is thus susceptible to fractures. The identification of the type and distribution of SRFs in geriatric patients provides useful information for determining risk factors and appropriate preventive measures that may reduce their incidence.


Assuntos
Traumatismos em Atletas , Fraturas Ósseas , Centros de Traumatologia , Humanos , Masculino , Feminino , Idoso , Centros de Traumatologia/tendências , Fraturas Ósseas/epidemiologia , Idoso de 80 Anos ou mais , Traumatismos em Atletas/epidemiologia , Estudos Retrospectivos
2.
Int J Mol Sci ; 25(8)2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38674090

RESUMO

Cinnamic acid (CA) was successfully incorporated into Zn-Al layered double hydroxide (LDH) through coprecipitation. The CA moiety was stabilized in the interlayer space through not only electrostatic interaction but also intermolecular π-π interaction. It was noteworthy that the CA arrangement was fairly independent of the charge density of LDH, showing the important role of the layer-CA and CA-CA interactions in molecular stabilization. Computer simulations using the Monte Carlo method as well as analytical approaches including infrared, UV-vis spectroscopy, and differential scanning calorimetry showed the existence of intermolecular interaction. In order to reinforce molecular stabilization, a neutral derivative of CA, cinnamaldehyde (CAD), was additionally incorporated into LDH. It was clearly shown that CAD played a role as a π-π interaction mediator to enhance the stabilization of CA. The time-dependent release of CA from LDH was first governed by the layer charge density of LDH; however, the existence of CAD provided additional stabilization to the CA arrangement to slow down the release kinetics.


Assuntos
Acroleína/análogos & derivados , Cinamatos , Preparações de Ação Retardada , Hidróxidos , Cinamatos/química , Hidróxidos/química , Preparações de Ação Retardada/química , Acroleína/química , Cinética , Método de Monte Carlo , Varredura Diferencial de Calorimetria
3.
Int J Mol Sci ; 24(13)2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37445736

RESUMO

Release of ferulic acid from surface-functionalized hollow nanoporous silica particles (HNSPs) was investigated in deionized water (DI water) and in ethanol. The host material, an HNSP, was synthesized in the presence of polymer and surfactant templates, and the pore as well as the surface were modified with either pentyltriethoxysilane (PTS) or octyltriethoxysilane (OTS) through silane coupling reactions. The inner hollow space occupied a volume of ~45% of the whole HNSP with a 2.54 nm pore channel in the wall. The pore size was estimated to decrease to 1.5 nm and 0.5 nm via the PTS and OTS functionalization, respectively. The encapsulation efficiencies of the HNSP (25 wt%), PTS-functionalized HNSP (PTS-HNSP, 22 wt%) and OTS-functionalized HNSP (OST-HNSP, 25 wt%) toward ferulic acid were similar, while the %release in DI water and ethanol varied following HNSP > PTS-HNSP > OTS-HNSP. Release kinetic analyses with Korsmeyer-Peppas fitting suggested a trade-off relationship between the solvent's ability to access the HNSP and the affinity of ferulic acid to the surface, allowing us to understand the solvent's controlled release rate and mechanism.


Assuntos
Nanoporos , Dióxido de Silício , Preparações de Ação Retardada , Água , Etanol , Solventes
4.
Molecules ; 28(16)2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37630324

RESUMO

Metal oxides (MOs) having Mg and Al with Mg/Al ratios of 1, 2, 3, and 4 were synthesized via calcination of the layered double hydroxides (LDH). The X-ray diffraction analysis revealed that all the MO consisted of periclase (MgO) crystallite with comparable crystallinity regardless of the metal ratio. According to the 27Al magic-angle spinning nuclear magnetic resonance, the phase transformation from LDH to MO upon calcination facilitated the evolution of the Al3+ ions with unsaturated coordination at the surface of MO. The specific surface area values of MOs were not significantly different from each other, ranging between 100 and 200 m2/g, suggesting that the metal ratio did not strongly influence the porous structure of MO. The temperature-dependent desorption of ammonia demonstrated that the Lewis acidity of the Al-rich MOs was the largest with an Mg/Al ratio of 1, attributed to the efficient exposure of the surface-active site Al3+-O2- pairs. The acidity of heterogenous Al-rich MOs significantly increased with the exposed tetrahedral Al site on the surface and dramatically diminished when the molar ratio (Mg/Al) was over two.

5.
Environ Res ; 205: 112532, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34896083

RESUMO

Two-dimensional (2D) transition metal carbides and nitrides (MXenes) have drawn considerable attention for application in the field of environmental remediation. In this study, we report the simultaneous reductive-adsorption behavior of Ti3CNTx for toxic metal ion Hg2+ ion in the aqueous phase. 2D Ti3CNTx and Ti3C2Tx MXene nanosheets were synthesized by exfoliation of Ti3AlCN and Ti3AlC2 MAX phases, respectively. Various characteristics analysis confirmed the successful fabrication of MAX phases and their exfoliation into MXenes. The fabricated MXene nanosheets were used to investigate their Hg2+ removal, Hg2+ intercalation, and surface interaction mechanism efficiencies. Both MXenes were found to adsorb and reduce a large amount of Hg2+. Analytical techniques such as X-ray powder diffraction, field emission transmission electron microscopy, zeta-potential analyses, and X-ray photoelectron spectroscopy were used to investigate the material characteristics and structural changes after uptake of Hg2+. The quantitative investigation confirmed the interaction of bimetal and hydroxyl groups with Hg2+ using electrostatic interactions and adsorption-coupled reduction. In addition, both MXenes exhibited extraordinary Hg ion removal capabilities in terms of fast kinetics with an excellent distribution coefficient (KdHg) up to 1.36 × 10+9. Based on batch adsorption results, Ti3C2Tx and Ti3CNTx exhibited removal capacities of 5473.13 and 4606.04 mg/g, respectively, for Hg2+, which are higher than those of previous Hg adsorbents.

6.
Int J Mol Sci ; 23(19)2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36232669

RESUMO

Interactions between layered double hydroxide (LDH) nanomaterials and plasma proteins according to their particle size and surface charge were evaluated. The LDHs with different particle size (150, 350 and 2000 nm) were prepared by adjusting hydrothermal treatment and urea hydrolysis and subsequent organic coating with citrate, malite and serite was applied to control the surface charge (ζ-potential: -15, 6 and 36 mV). Adsorption isotherms and Stern-Volmer plots for fluorescence quenching indicated that the human blood plasma had weak interactions toward all the types of LDHs. The adsorption isotherms did not show significant differences in the size and surface charges, while the fluorescence quenching ratio increased with the increase in the surface charge, implying that electrostatic interaction played a major role in their interactions. The fluorescence quenching of three types of plasma proteins (human serum albumin, γ-globulin and fibrinogen) by the surface charge-controlled LDHs suggested that the proteins adsorbed on the LDHs with a single layer and additional proteins were weakly adsorbed to surround the LDHs with adsorbed proteins. It was concluded that the LDH nanomaterials are fairly compatible for blood components due to the protein corona while the electrostatic interaction can affect their interaction with the proteins.


Assuntos
Coroa de Proteína , Citratos , Fibrinogênio , Humanos , Hidróxidos , Albumina Sérica Humana , Ureia , gama-Globulinas
7.
J Environ Manage ; 277: 111455, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33075656

RESUMO

Systematic utilization of carbonated Mg-Al layered double hydroxide (LDH) nanosheets for methyl orange removal was investigated with respect to particle dimensions. LDHs with the smallest dimensions were carefully synthesized to have a small lateral size as well as high dispersibility. The other particles, with medium and large sizes, were prepared by hydrothermal treatment and urea hydrolysis to have larger sizes and higher crystallinity. According to kinetics and isotherm analyses, the smallest LDH showed efficient adsorption of methyl orange (1250 mg/g-LDH), which was remarkably higher than the adsorption by the other LDHs with larger lateral sizes. Unlike the larger lateral-sized LDHs, the small ones were shown to utilize all accessible adsorption sites on the nanosheets, generating nanoconfinement of methyl orange molecules. Transmission electron microscopy (TEM) and powder X-ray diffraction (PXRD) patterns indicated that the LDHs with lateral dimensions of ~40 nm fully utilized interlayer nanospace. Monte Carlo simulation suggested that the intercalated methyl orange was stabilized not only through electrostatic interactions with the LDH layer but also by π-π stacking between the methyl orange molecules, which is thought to be the driving force for replacement of carbonate anions.


Assuntos
Poluentes Químicos da Água , Compostos Azo , Hidróxidos , Água
8.
Inorg Chem ; 59(4): 2163-2170, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-31887019

RESUMO

Silver metal nanostructures have gained much interest, due to their utility in various fields, based on their unique properties at nanosize. Tremendous research efforts have been made to establish synthetic methods to manipulate their shape and size. The most challenging synthesis in silver nanostructures has been known as a plate-like shape having a few nanometers size thickness and high aspect ratio. Here, we demonstrate a novel and facile synthetic route for ultrathin (≤1 nm) silver nanosheets using silver carboxylthiolate as precursor. Such silver thiolate formed single-layered colloid in aqueous basic solution, due to the electrostatic repulsion between carboxylate groups. These single layers of silver thiolates were stabilized within the interlayer space of layered double hydroxide (LDH). When silver thiolates confined in LDHs were calcined under reductive atmosphere, the LDHs effectively suppressed the vertical growth of silver crystals.

9.
Mov Disord ; 32(8): 1211-1220, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28548297

RESUMO

BACKGROUND AND OBJECTIVES: Many hereditary movement disorders with complex phenotypes without a locus symbol prefix for familial PD present as parkinsonism; however, the dysregulation of genes associated with these phenotypes in the SNpc of PD patients has not been systematically studied. METHODS: Gene set enrichment analyses were performed using 10 previously published genome-wide expression datasets obtained by laser-captured microdissection of pigmented neurons in the SNpc. A custom-curated gene set for hereditary parkinsonism consisting of causative genes (n = 78) related to disorders with a parkinsonism phenotype, but not necessarily idiopathic or monogenic PD, was constructed from the Online Mendelian Inheritance in Man database. RESULTS: In 9 of the 10 gene expression data sets, gene set enrichment analysis showed that the disease-causing genes for hereditary parkinsonism were downregulated in the SNpc in PD patients compared to controls (nominal P values <0.05 in five studies). Among the 63 leading edge subset genes representing downregulated genes in PD, 79.4% were genes without a locus symbol prefix for familial PD. A meta-gene set enrichment analysis performed with a random-effect model showed an association between the gene set for hereditary parkinsonism and PD with a negative normalized enrichment score value (-1.40; 95% CI: -1.52∼-1.28; P < 6.2E-05). CONCLUSION: Disease-causing genes with a parkinsonism phenotype are downregulated in the SNpc in PD. Our study highlights the importance of genes associated with hereditary movement disorders with parkinsonism in understanding the pathogenesis of PD. © 2017 International Parkinson and Movement Disorder Society.


Assuntos
Regulação da Expressão Gênica/genética , Predisposição Genética para Doença , Mutação/genética , Doença de Parkinson/genética , Transtornos Parkinsonianos/genética , Substância Negra/fisiopatologia , Bases de Dados como Assunto , Ontologia Genética , Estudos de Associação Genética/métodos , Estudos de Associação Genética/estatística & dados numéricos , Humanos , Doença de Parkinson/patologia , Transtornos Parkinsonianos/patologia , Fenótipo , Substância Negra/patologia
10.
Biochem Biophys Res Commun ; 448(2): 157-62, 2014 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-24755077

RESUMO

Mitochondrial dysfunction is a common and prominent feature of many neurodegenerative diseases, including prion diseases; it is induced by oxidative stress in scrapie-infected animal models. In previous studies, we found swelling and dysfunction of mitochondria in the brains of scrapie-infected mice compared to brains of controls, but the mechanisms underlying mitochondrial dysfunction remain unclear. To examine whether the dysregulation of mitochondrial proteins is related to the mitochondrial dysfunction associated with prion disease, we investigated the expression patterns of mitochondrial fusion and fission proteins in the brains of ME7 prion-infected mice. Immunoblot analysis revealed that Mfn1 was up-regulated in both whole brain and specific brain regions, including the cerebral cortex and hippocampus, of ME7-infected mice compared to controls. Additionally, expression levels of Fis1 and Mfn2 were elevated in the hippocampus and the striatum, respectively, of the ME7-infected brain. In contrast, Dlp1 expression was significantly reduced in the hippocampus in the ME7-infected brain, particularly in the cytosolic fraction. Finally, we observed abnormal mitochondrial enlargement and histopathological change in the hippocampus of the ME7-infected brain. These observations suggest that the mitochondrial dysfunction, which is presumably caused by the dysregulation of mitochondrial fusion and fission proteins, may contribute to the neuropathological changes associated with prion disease.


Assuntos
Encéfalo/patologia , Mitocôndrias/patologia , Dinâmica Mitocondrial , Scrapie/patologia , Animais , Encéfalo/metabolismo , Citosol/metabolismo , Modelos Animais de Doenças , Dinaminas/metabolismo , GTP Fosfo-Hidrolases , Hipocampo/metabolismo , Hipocampo/patologia , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas PrPSc/metabolismo , Scrapie/metabolismo
11.
Artigo em Inglês | MEDLINE | ID: mdl-24462964

RESUMO

The industrial application of nanotechnology, particularly using zinc oxide (ZnO), has grown rapidly, including products such as cosmetics, food, rubber, paints, and plastics. However, despite increasing population exposure to ZnO, its potential genotoxicity remains controversial. The biological effects of nanoparticles depend on their physicochemical properties. Preparations with well-defined physico-chemical properties and standardized test methods are required for assessing the genotoxicity of nanoparticles. In this study, we have evaluated the genotoxicity of four kinds of ZnO nanoparticles: 20nm and 70nm size, positively or negatively charged. Four different genotoxicity tests (bacterial mutagenicity assay, in vitro chromosomal aberration test, in vivo comet assay, and in vivo micronucleus test, were conducted, following Organization for Economic Cooperation and Development (OECD) test guidelines with good laboratory practice (GLP) procedures. No statistically significant differences from the solvent controls were observed. These results suggest that surface-modified ZnO nanoparticles do not induce genotoxicity in in vitro or in vivo test systems.


Assuntos
Dano ao DNA , Nanopartículas Metálicas/toxicidade , Óxido de Zinco/toxicidade , Animais , Células Cultivadas , Ensaio Cometa/métodos , Cricetinae , Cricetulus , Masculino , Camundongos , Camundongos Endogâmicos ICR , Testes para Micronúcleos , Ratos , Ratos Sprague-Dawley
12.
Int J Mol Sci ; 15(12): 22563-79, 2014 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-25490138

RESUMO

We have successfully prepared layered double hydroxide (LDH) nanomaterials containing calcium and aluminum ions in the framework (CaAl-LDH). The surface of CaAl-LDH was coated with enteric polymer, Eudragit®L 100 in order to protect nanomaterials from fast dissolution under gastric condition of pH 1.2. The X-ray diffraction patterns, Fourier transform infrared spectroscopy, scanning electron and transmission electron microscopy revealed that the pristine LDH was well prepared having hydrocalumite structure, and that the polymer effectively coated the surface of LDH without disturbing structure. From thermal analysis, it was determined that only a small amount (less than 1%) of polymer was coated on the LDH surface. Metal dissolution from LDH nanomaterials was significantly reduced upon Eudragit®L 100 coating at pH 1.2, 6.8 and 7.4, which simulates gastric, enteric and plasma conditions, respectively, and the dissolution effect was the most suppressed at pH 1.2. The LDH nanomaterials did not exhibit any significant cytotoxicity up to 1000 µg/mL and intracellular calcium concentration significantly increased in LDH-treated human intestinal cells. Pharmacokinetic study demonstrated absorption efficiency of Eudragit®L 100 coated LDH following oral administration to rats. Moreover, the LDH nanomaterials did not cause acute toxic effect in vivo. All the results suggest the great potential of CaAl-LDH nanomaterials as a calcium supplement.


Assuntos
Alumínio/química , Cálcio/química , Suplementos Nutricionais , Portadores de Fármacos/química , Hidróxidos/química , Nanoestruturas/química , Polímeros/química , Animais , Cálcio/administração & dosagem , Cálcio/farmacocinética , Linhagem Celular , Sobrevivência Celular , Humanos , Masculino , Nanoestruturas/ultraestrutura , Ratos , Espectroscopia de Infravermelho com Transformada de Fourier , Testes de Toxicidade Aguda
13.
Sci Rep ; 14(1): 5188, 2024 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-38431723

RESUMO

Total knee arthroplasty (TKA) is associated with substantial blood loss and tranexamic acid (TXA) effectively reduces postoperative bleeding. Although it is known that there is no difference between intravenous or intra-articular (IA) injection, the general interest is directed towards topical hemostatic agents regarding thromboembolic events in high-risk patients. This study aimed to compare the blood conservation effects of IA MPH powder and TXA in patients undergoing primary TKA. We retrospectively analyzed 103 patients who underwent primary TKA between June 2020 and December 2021. MPH powder was applied to the IA space before capsule closure (MPH group, n = 51). TXA (3 g) was injected via the drain after wound closure (TXA group, n = 52). All patients underwent drain clamping for three postoperative hours. The primary outcome was the drain output, and the secondary outcomes were the postoperative hemoglobin (Hb) levels during the hospitalization period and the perioperative blood transfusion rates. An independent Student's t-test was used to determine differences between the two groups. The drain output in the first 24 h after surgery was significantly higher in the MPH group than in the TXA group. The postoperative Hb levels were significantly lower in the MPH group than in the TXA group. In patients with simultaneous bilateral TKA, there was a significant difference in the blood transfusion volumes and the rates between groups. It is considered that IA MPH powder cannot replace IA TXA because of an inferior efficacy in reducing blood loss and maintaining postoperative Hb levels in the early postoperative period after primary TKA. Moreover, in the case of simultaneous bilateral TKA, we do not recommend the use of IA MPH powder because it was notably less effective in the field of transfusion volume and rate.


Assuntos
Antifibrinolíticos , Artroplastia do Joelho , Ácido Tranexâmico , Humanos , Artroplastia do Joelho/efeitos adversos , Pós , Antifibrinolíticos/uso terapêutico , Estudos Retrospectivos , Hemorragia Pós-Operatória/prevenção & controle , Hemorragia Pós-Operatória/induzido quimicamente , Injeções Intra-Articulares , Administração Intravenosa , Perda Sanguínea Cirúrgica/prevenção & controle
14.
ScientificWorldJournal ; 2013: 421967, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24453848

RESUMO

We have successfully prepared nanohybrids of biofunctional ferulic acid and layered double hydroxide nanomaterials through reconstruction and exfoliation-reassembly routes. From X-ray diffraction and infrared spectroscopy, both nanohybrids were determined to incorporate ferulic acid molecules in anionic form. Microscopic results showed that the nanohybrids had average particle size of 150 nm with plate-like morphology. As the two nanohybridization routes involved crystal disorder and random stacking of layers, the nanohybrids showed slight alteration in z-axis crystallinity and particle size. The zeta potential values of pristine and nanohybrids in deionized water were determined to be positive, while those in cell culture media shifted to negative values. According to the in vitro anticancer activity test on human cervical cancer HeLa cells, it was revealed that nanohybrids showed twice anticancer activity compared with ferulic acid itself. Therefore we could conclude that the nanohybrids of ferulic acid and layered double hydroxide had cellular delivery property of intercalated molecules on cancer cell lines.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Ácidos Cumáricos/química , Ácidos Cumáricos/farmacologia , Hidróxidos/química , Nanoestruturas/química , Células HeLa , Humanos , Tamanho da Partícula , Espectrofotometria Infravermelho , Sais de Tetrazólio , Tiazóis , Difração de Raios X
15.
Nanomaterials (Basel) ; 13(3)2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36770528

RESUMO

The emulsifying ability of the naturally occurring surfactant deoxycholic acid (DCA) was improved by dynamic interaction with nanometric layered particles, layered double hydroxide (LDH). As DCA molecules are rigid due to the facial configuration of hydrophobic-hydrophilic groups, they tend to form molecular aggregation in an acidic condition or imbalanced water-lipid ratios. In this study, the homogeneous hybrids of DCA and LDH were obtained by the in situ growth of LDH at a DCA molecule. The DCA-LDH hybrid successfully prevented the molecular aggregation of DCA at an acidic pH and imbalanced water-to-oil ratio. The dynamic light scattering showed that the hydrodynamic radius of micelle in the emulsion made with DCA-LDH maintained its small size (<500 nm), while upon pH change and dilution with water, that made with DCA only uncontrollably increased up to ~3000 nm. The polydispersity index value of the DCA-LDH emulsion remained constant (<0.3) after the pH change and dilution with water, indicating the high stability of the formulation. Furthermore, time-dependent turbidity monitoring revealed that the DCA-only formulation suffered from serious coalescence and creaming compared with the DCA-LDH formulation. It is suggested that the dynamic interaction between LDH layers and DCA prevented molecular aggregation under unfavorable conditions for the oil-in-water emulsion.

16.
Clin Shoulder Elb ; 26(2): 208-211, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37088882

RESUMO

We describe the case of a 49-year-old right hand-dominant woman with myositis of the biceps brachii muscle unrelated to the inoculation site following Pfizer-BioNTech COVID-19 vaccination on the deltoid muscle of the left shoulder. Coronavirus disease 2019 (COVID-19) pandemic has involved global spread, and different vaccines including inactivated, protein, vectored, and nucleic acid vaccines have been developed and administered. Common side effects of COVID-19 vaccines include general manifestations such as headache, fever, and fatigue, and various musculoskeletal symptoms. Here, we present a case of myositis occurring in the biceps brachii muscle unrelated to the inoculation site, which has not been reported previously, accompanied by a literature review.

17.
R Soc Open Sci ; 10(10): 230506, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37830016

RESUMO

Deoxycholate (DA) is a natural emulsifying agent involved in the absorption of dietary lipids. Due to the facial distribution of hydrophobic-hydrophilic region, DA easily aggregates under ambient conditions, and this property hinders the practical application of DA in clinical applications. In this study, we found that the molecular arrangement of DA molecules could be controlled by using layered double hydroxide (LDH) under a specific reaction condition. The effect of reaction methods such as co-precipitation, ion exchange and reconstruction on the molecular arrangement of DA was investigated by X-ray diffraction, Fourier-transform infrared spectroscopy, high-resolution transmission electron microscopy and differential scanning calorimetry. It was demonstrated that the self-aggregation of DA molecules could be suppressed by the oriented arrangement of DA between the gallery space of LDH. The DA moiety was well stabilized in the LDH layers due to the electrostatic interaction between DA molecules and LDH layers. The most ordered arrangement of DA molecules was observed when DA was incorporated into LDH via a reconstruction method. The DA molecules arranged in LDH via reconstruction did not show significant exothermic or endothermic behaviour up to 400°C, showing that the DA moiety lost its intermolecular attraction in between LDH layers.

18.
Materials (Basel) ; 16(19)2023 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-37834660

RESUMO

A drug-delivery system consisting of an inorganic host-layered double hydroxide (LDH)-and an anticancer drug-methotrexate (MTX)-was prepared via the intercalation route (MTX-LDH), and its hematocompatibility was investigated. Hemolysis, a red blood cell counting assay, and optical microscopy revealed that the MTX-LDH had no harmful toxic effect on blood cells. Both scanning electron microscopy and atomic force microscopy exhibited that the MTX-LDH particles softly landed on the concave part inred blood cells without serious morphological changes of the cells. The time-dependent change in the surface charge and hydrodynamic radius of MTX-LDH in the plasma condition demonstrated that the proteins can be gently adsorbed on the MTX-LDH particles, possibly through protein corona, giving rise to good colloidal stability. The fluorescence quenching assay was carried out to monitor the interaction between MTX-LDH and plasma protein, and the result showed that the MTX-LDH had less dynamic interaction with protein compared with MTX alone, due to the capsule moiety of the LDH host. It was verified by a quartz crystal microbalance assay that the surface interaction between MTX-LDH and protein was reversible and reproducible, and the type of protein corona was a soft one, having flexibility toward the biological environment.

19.
RSC Adv ; 13(8): 5529-5537, 2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-36798609

RESUMO

Hyaluronic acid (HA) is a natural linear polysaccharide which has been widely used in cosmetics and pharmaceuticals including drug delivery systems because of its excellent biocompatibility. In this study, we investigated the one-pot synthesis of HA-coated gold nanoparticles (AuNP-HA) as a drug delivery carrier. The HAs with different molecular weights were produced by e-beam irradiation and employed as coating materials for AuNPs. Sulfasalazine (SSZ), a poorly water-soluble drug, was used to demonstrate the efficiency of drug delivery and the controlled release behaviour of the AuNP-HA. As the molecular weight of the HA decreased, the drug encapsulation efficiency of the SSZ increased up to 94%, while drug loading capacity of the SSZ was maintained at the level of about 70%. The prepared AuNP-HA-SSZ exhibited slow release of the SSZ over a short time and excellent sensitivity to different pHs and physiological conditions. The SSZ release rate was the lowest in simulated gastric conditions and the highest in simulated intestinal conditions. In this case, the AuNP-HA protects the SSZ from release under the acidic pH conditions in the stomach; on the other hand, the drug release was facilitated in the basic environment of the small intestine and colon. The SSZ was released under simulated intestinal conditions through anomalous drug transport and followed the Korsmeyer-Peppas model. Therefore, this study suggests that AuNP-HA is a promising orally-administered and intestine-targeted drug delivery system with controlled release characteristics.

20.
Bioengineering (Basel) ; 10(6)2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37370665

RESUMO

Layered Double Hydroxides (LDHs) are inorganic compounds of relevance to various domains, where their surface reactivity and/or intercalation capacities can be advantageously exploited for the retention/release of ionic and molecular species. In this study, we have explored specifically the applicability in the field of bone regeneration of one LDH composition, denoted "MgFeCO3", of which components are already present in vivo, so as to convey a biocompatibility character. The propensity to be used as a bone substitute depends, however, on their ability to allow the fabrication of 3D constructs able to be implanted in bone sites. In this work, we display two appealing approaches for the processing of MgFeCO3 LDH particles to prepare (i) porous 3D scaffolds by freeze-casting, involving an alginate biopolymeric matrix, and (ii) pure MgFeCO3 LDH monoliths by Spark Plasma Sintering (SPS) at low temperature. We then explored the capacity of such LDH particles or monoliths to interact quantitatively with molecular moieties/drugs in view of their local release. The experimental data were complemented by computational chemistry calculations (Monte Carlo) to examine in more detail the mineral-organic interactions at play. Finally, preliminary in vitro tests on osteoblastic MG63 cells confirmed the high biocompatible character of this LDH composition. It was confirmed that (i) thermodynamically metastable LDH could be successfully consolidated into a monolith through SPS, (ii) the LDH particles could be incorporated into a polymer matrix through freeze casting, and (iii) the LDH in the consolidated monolith could incorporate and release drug molecules in a controlled manner. In other words, our results indicate that the MgFeCO3 LDH (pyroaurite structure) may be seen as a new promising compound for the setup of bone substitute biomaterials with tailorable drug delivery capacity, including for personalized medicine.

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