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1.
J Mater Chem B ; 12(36): 8993-9004, 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39145426

RESUMEN

Among external stimuli-responsive therapy approaches, those using near infrared (NIR) light irradiation have attracted significant attention to treat bone-related diseases and bone tissue regeneration. Therefore, the development of metallic biomaterials sensitive to NIR stimuli is an important area of research in orthopaedics. In this study, we have generated in situ prism-shaped silver nanoparticles (p-AgNPs) in a biomorphic nano-holed TiO2 coating on a Ti6Al4V alloy (a-Ti6Al4V). Insertion of p-AgNPs does not disturb the periodically arranged sub-wavelength-sized unit cell on the a-Ti6Al4V dielectric structure, while they exacerbate its peculiar optical response, which results in a higher NIR reflectivity and high efficiency of NIR photothermal energy conversion suitable to bacterial annihilation. Together, these results open a promising path toward strategic bone therapeutic procedures, providing novel insights into precision medicine.


Asunto(s)
Aleaciones , Antibacterianos , Rayos Infrarrojos , Nanopartículas del Metal , Plata , Propiedades de Superficie , Titanio , Titanio/química , Titanio/farmacología , Aleaciones/química , Aleaciones/farmacología , Plata/química , Plata/farmacología , Antibacterianos/farmacología , Antibacterianos/química , Nanopartículas del Metal/química , Staphylococcus aureus/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Escherichia coli/efectos de los fármacos , Tamaño de la Partícula
2.
Nanotechnology ; 35(46)2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39116890

RESUMEN

The translation of silver-based nanotechnology 'from bench to bedside' requires a deep understanding of the molecular aspects of its biological action, which remains controversial at low concentrations and non-spherical morphologies. Here, we present a hemocompatibility approach based on the effect of the distinctive electronic charge distribution in silver nanoparticles (nanosilver) on blood components. According to spectroscopic, volumetric, microscopic, dynamic light scattering measurements, pro-coagulant activity tests, and cellular inspection, we determine that at extremely low nanosilver concentrations (0.125-2.5µg ml-1), there is a relevant interaction effect on the serum albumin and red blood cells (RBCs). This explanation has its origin in the surface charge distribution of nanosilver particles and their electron-mediated energy transfer mechanism. Prism-shaped nanoparticles, with anisotropic charge distributions, act at the surface level, generating a compaction of the native protein molecule. In contrast, the spherical nanosilver particle, by exhibiting isotropic surface charge, generates a polar environment comparable to the solvent. Both morphologies induce aggregation at NPs/bovine serum albumin ≈ 0.044 molar ratio values without altering the coagulation cascade tests; however, the spherical-shaped nanosilver exerts a negative impact on RBCs. Overall, our results suggest that the electron distributions of nanosilver particles, even at extremely low concentrations, are a critical factor influencing the molecular structure of blood proteins' and RBCs' membranes. Isotropic forms of nanosilver should be considered with caution, as they are not always the least harmful.


Asunto(s)
Eritrocitos , Nanopartículas del Metal , Albúmina Sérica Bovina , Plata , Plata/química , Nanopartículas del Metal/química , Eritrocitos/metabolismo , Eritrocitos/química , Humanos , Albúmina Sérica Bovina/química , Albúmina Sérica Bovina/metabolismo , Propiedades de Superficie , Animales , Bovinos , Coagulación Sanguínea/efectos de los fármacos , Proteínas Sanguíneas/metabolismo , Proteínas Sanguíneas/química , Ensayo de Materiales
3.
ACS Appl Mater Interfaces ; 15(21): 25884-25897, 2023 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-37208817

RESUMEN

Following the secular idea of ″restitutio ad integrum″, regeneration is the pursued option to restore bones lost after a disease; accordingly, complementing antibiotic and regeneration capacity to bone grafts represents a great scientific success. This study is a framework proposal for understanding the antimicrobial effect of biocompatible nano-hydroxyapatite/MoOx (nano-HA/MoOx) platforms on the basis of their electroactive behavior. Through cyclic voltammetry and chronoamperometry measurements, the electron transference capacity of nano-HA and nano-HA/MoOx electrodes was determined in the presence of pathogenic organisms: Pseudomonas aeruginosa and Staphylococcus aureus. Faradaic processes were confirmed and related to the switch of MoO42-/PO43- groups in the original hexagonal nano-HA crystal lattice and to the extent of OH vacancies that act as electron acceptors. Microscopic analysis of bacteria's ultrastructure showed a disruptive effect on the cytoplasmic membrane upon direct contact with the materials, which is not evident in the presence of eukaryotic cells. Experiments support the existence of a type of extracellular electron transfer (EET) process that alters the function of the bacterial cytoplasmic membrane, accelerating their death. Our findings provide strong quantitative support for a drug-independent biocidal physical approach based on EET processes between microorganisms and phosphate ceramics that can be used to combat local orthopedic infections associated with implants.


Asunto(s)
Durapatita , Infecciones Estafilocócicas , Humanos , Durapatita/farmacología , Durapatita/química , Antibacterianos/farmacología , Antibacterianos/química , Bacterias , Huesos
4.
Adv Colloid Interface Sci ; 304: 102682, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35489142

RESUMEN

The rise in the use of biomaterials in bone regeneration in the last decade has exponentially multiplied the number of publications, methods, and approaches to improve and optimize their functionalities and applications. In particular, biomimetic strategies based on the self-assembly of molecules to design, create and characterize nanostructured materials have played a very relevant role. We address this idea on four different but related points: self-setting bone cements based on calcium phosphate, as stable tissue support and regeneration induction; metallic prosthesis coatings for cell adhesion optimization and prevention of inflammatory response exacerbation; bio-adhesive hybrid materials as multiple drug delivery localized platforms and finally bio-inks. The effect of the physical, chemical, and biological properties of the newest biomedical devices on their bone tissue regenerative capacity are summarized, described, and analyzed in detail. The roles of experimental conditions, characterization methods and synthesis routes are emphasized. Finally, the future opportunities and challenges of nanostructured biomaterials with their advantages and shortcomings are proposed in order to forecast the future directions of this field of research.


Asunto(s)
Nanoestructuras , Ingeniería de Tejidos , Materiales Biocompatibles/farmacología , Regeneración Ósea , Huesos , Ingeniería de Tejidos/métodos
5.
ACS Appl Mater Interfaces ; 14(4): 5843-5855, 2022 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-35048694

RESUMEN

Near-infrared (NIR) radiation plays an important role in guided external stimulus therapies; its application in bone-related treatments is becoming more and more frequent. Therefore, metallic biomaterials that exhibit properties activated by NIR are promising for further orthopedic procedures. In this work, we present an adapted electroforming approach to attain a biomorphic nano-holed TiO2 coating on Ti6Al4V alloy. Through a precise control of the anodization conditions, structures revealed the formation of localized nano-pores arranged in a periodic assembly. This specific organization provoked higher stability against thermal oxidation and precise hydrophobic wettability behavior according to Cassie-Baxter's model; both characteristics are a prerequisite to ensure a favorable biological response in an implantable structure for guided bone regeneration. In addition, the periodically arranged sub-wavelength-sized unit cell on the metallic-dielectric structure exhibits a peculiar optical response, which results in higher NIR reflectivity. Accordingly, we have proved that this effect enhances the efficiency of the scattering processes and provokes a significant improvement of light confinement producing a spontaneous NIR fluorescence emission. The combination of the already favorable mechanical and biocompatibility properties of Ti6Al4V, along with suitable thermal stability, wetting, and electro-optical behavior, opens a promising path toward strategic bone therapeutic procedures.


Asunto(s)
Aleaciones/química , Materiales Biomiméticos/química , Materiales Biocompatibles Revestidos/química , Aleaciones/efectos de la radiación , Materiales Biomiméticos/efectos de la radiación , Materiales Biocompatibles Revestidos/efectos de la radiación , Interacciones Hidrofóbicas e Hidrofílicas , Rayos Infrarrojos , Porosidad , Titanio/química , Titanio/efectos de la radiación , Humectabilidad
6.
Mater Sci Eng C Mater Biol Appl ; 115: 111101, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32600705

RESUMEN

Bone substitute materials based on bioceramics and polymers have evolved shifting from a passive role where they are merely accepted by the body; to an active role, where they respond to particular environmental conditions or to different types of cues generating suitable integration (osseointegration for this case) inside the host tissue. In this work, two types of composite materials based on a bioceramic (synthetic nano-hydroxyapatite, HA) and a biopolymer (sodium alginate, ALG) have been designed and assessed for promoting the bone regeneration. These materials were loaded with ciprofloxacin (CIP) for obtaining, not only a suitable material for a filling but with antibacterial properties. Therefore, their main features were studied through Fourier transformed-infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Ultraviolet-Visible (UV-Vis) spectroscopy was used for obtaining the released concentrations of CIP and Zeta-potential (ζ-potential) was used for characterizing the adsorption of CIP onto nanoparticles. The release profile of this drug has been fit with the Ritger-Peppas model, used for studying the release kinetics of hydrogel-based systems. The bioactivity of these composites was also evaluated after 30 days of incubation in a simulated body fluid solution (SBF). Then, the assessment of antibacterial capability against the three main strains cause osteomyelitis was performed. Finally, the cell viability study and the cellular morphology assay were also carried out. These last assays have shown encouraging results and, gathered with their other properties, such as their bioactivity and antibacterial properties; they could lead to propose these materials as new bone filler antibiotic devices.


Asunto(s)
Alginatos/química , Antibacterianos/farmacología , Sustitutos de Huesos/farmacología , Ciprofloxacina/farmacología , Durapatita/química , Osteoblastos/citología , Animales , Antibacterianos/química , Bacterias/efectos de los fármacos , Sustitutos de Huesos/química , Línea Celular , Supervivencia Celular , Ciprofloxacina/química , Liberación de Fármacos , Microscopía Electrónica de Transmisión , Nanopartículas , Ratas , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
7.
J Colloid Interface Sci ; 572: 408-420, 2020 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-32272315

RESUMEN

BACKGROUND AND AIM: Membranes for guided bone regeneration should have a mechanical structure and a chemical composition suitable for mimicking biological structures. In this work, we pursue the development of periosteum-inspired bilayered membranes obtained by crosslinking alginate with different amounts of nanohydroxyapatite. EXPERIMENTS: Alginate-nanohydroxyapatite interaction was studied by rheology and infrared spectroscopy measurements. The membranes were characterized regarding their tensile strength, degradation and surface morphology. Finally, cell cultures were performed on each side of the membranes. FINDINGS: The ionic bonding between alginate polysaccharide networks and nanohydroxyapatite was proven, and had a clear effect in the strength and microstructure of the hydrogels. Distinct surface characteristics were achieved on each side of the membranes, resulting in a highly porous fibrous side and a mineral-rich side with higher roughness and lower porosity. Moreover, the effect of amount of nanohydroxyapatite was reflected in a decrease of the membranes' plasticity and an increment of degradation rate. Finally, it was proved that osteoblast-like cells proliferated and differentiated on the mineral-rich side, specially when a higher amount of nanohydroxyapatite was used, whereas fibroblasts-like cells were able to proliferate on the fibrous side. These periosteum-inspired membranes are promising biomaterials for guided tissue regeneration applications.


Asunto(s)
Alginatos/química , Materiales Biomiméticos/química , Durapatita/química , Membrana Dobles de Lípidos/química , Nanopartículas/química , Periostio/química , Diferenciación Celular , Células Cultivadas , Humanos , Osteoblastos/química , Osteoblastos/citología , Tamaño de la Partícula , Propiedades de Superficie
8.
Nanoscale ; 11(37): 17277-17292, 2019 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-31512695

RESUMEN

Nowadays, the repair of large-size bone defects represents a huge medical challenge. A line of attack is the construction of advanced biomaterials having multifunctional properties. In this work, we show the creation of biocompatible MoOx-hydroxyapatite nanoparticles (nano-HA/MoOx) that simultaneously exhibit self-activated fluorescence and antibiotic skills. Along this text, we demonstrate that the insertion of molybdenum, an essential trace element, into the non-stoichiometric calcium deficient hydroxyapatite lattice generates intrinsic electronic point defects that exacerbate its epifluorescence blue emission and provokes new red emissions, preserving, always, its bioactivity. Furthermore, these point defects, acting as electron acceptors, stimulate the materials' biological redox status and promote the death of pathogen microorganisms after their direct contact. A putative mechanism, by which bacteria lose electrons from their metabolic circuit that alter the function of their cytoplasmic membrane and potentially die, agrees with our results. Our findings highlight the importance of tuning the electronic communications between biomaterial interfaces and biological units, and support the use of self-fluorescent MoOx-hydroxyapatite nanoparticles as fundamental building blocks for new real-time imaging platforms against bone infection.


Asunto(s)
Antibacterianos/química , Infecciones Bacterianas/tratamiento farmacológico , Durapatita/química , Colorantes Fluorescentes/química , Nanopartículas/química , Osteomielitis/tratamiento farmacológico , Nanomedicina Teranóstica
9.
Mater Sci Eng C Mater Biol Appl ; 99: 180-190, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30889690

RESUMEN

The use of high doses of antibacterial and anti-inflammatory drugs for patients with bone diseases, associated to implants or bone filling, can develop adverse effects; and consequently, it promotes to think new strategies to avoid this problem. In this work, it has been described the adsorption/release (or desorption) behavior of two drugs, ciprofloxacin (CIP) and ibuprofen (IBU), onto hydroxyapatite (nano-HA) at 37 °C. Through Ultraviolet-Visible (UV-Vis) spectroscopy, the concentrations of both drugs in adsorption, kinetic and desorption processes were obtained. The Fourier Transformed-Infrared (FT-IR) spectroscopy, Zeta-potential (ζ-potential), High-Resolution Transmission Electron Microscopy (H-TEM) and x-Ray Diffraction (xRD) were also used to characterize bared nanoparticles and those with adsorbed drugs. Five adsorption models (Langmuir, Freundlich, Sips, Temkin and Dubinin-Radushkevich) were used for describing the behavior of both active compounds. The adsorption processes (CIP/nano-HA and IBU/nano-HA) were better predicted by the Sips model than by the others. The kinetic adsorption data were processed, for both active agents, by application of Avrami's model. Desorption/release process (of both drugs) was evaluated though Korsmeyer-Peppas (K-P) model. Owing to the predictability of these systems, we propose the use of these active ceramics as potential bone filler for improving the treatment against bacterial bone infections and to avoid its associated inflammatory process.


Asunto(s)
Antibacterianos/farmacología , Antiinflamatorios/farmacología , Durapatita/química , Nanotubos/química , Adsorción , Antibacterianos/química , Antiinflamatorios/química , Ciprofloxacina/química , Ciprofloxacina/farmacología , Concentración de Iones de Hidrógeno , Ibuprofeno/química , Ibuprofeno/farmacología , Cinética , Nanotubos/ultraestructura , Concentración Osmolar , Espectroscopía Infrarroja por Transformada de Fourier , Electricidad Estática
10.
Colloids Surf B Biointerfaces ; 175: 596-605, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30580150

RESUMEN

Biomaterials are frequently evaluated for pro-coagulant activity but usually in the presence of microparticles (MPs), cell-derived vesicles in blood plasma whose phospholipid surfaces allow coagulation factors to set up as functional assemblies. We tested the hypothesis that synthetic anionic surfaces can catalyze burst thrombin activation in human blood plasma in the absence of MPs. In a thromboelastography (TEG) assay with plastic sample cups and pins, recalcified human citrated platelet-poor plasma spontaneously burst-coagulated but with an unpredictable clotting time whereas plasma depleted of MPs by ultracentrifugation failed to coagulate. Coagulation of MP-depleted plasma was restored in a dose-dependent manner by glass microbeads, hydroxyapatite nanoparticles (HA NPs), and carboxylic acid-containing anionic nanocoatings of TEG cups and pins (coated by glow-discharge plasma-polymerized ethylene containing oxygen, L-PPE:O with 4.4 and 6.8 atomic % [COOH]). Glass beads lost their pro-coagulant activity in MP-depleted plasma after their surfaces were nanocoated with hydrophobic plasma-polymerized hexamethyl disiloxane (PP-HMDSO). In FXII-depleted MP-depleted plasma, glass microbeads failed to induce coagulation, however, FXIa was sufficient to induce coagulation in a dose-dependent manner, with no effect of glass beads. These data suggest that anionic surfaces of crystalline, organic, and amorphous solid synthetic materials catalyze explosive thrombin generation in MP-depleted plasma by activating the FXII-dependent intrinsic contact pathway. The data also show that microparticles are pro-coagulant surfaces whose activity has been largely overlooked in many coagulation studies to-date. These results suggest a possible mechanism by which anionic biomaterial surfaces induce bone healing by contact osteogenesis, through fibrin clot formation in the absence of platelet activation.


Asunto(s)
Materiales Biocompatibles/farmacología , Coagulación Sanguínea/efectos de los fármacos , Micropartículas Derivadas de Células/química , Durapatita/farmacología , Nanopartículas/química , Siloxanos/farmacología , Aniones , Materiales Biocompatibles/química , Plaquetas/citología , Plaquetas/efectos de los fármacos , Durapatita/química , Factor XII/metabolismo , Vidrio/química , Humanos , Membranas Artificiales , Siloxanos/química , Propiedades de Superficie , Tromboelastografía , Trombina/metabolismo
11.
Int J Pharm ; 548(1): 559-570, 2018 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-30016671

RESUMEN

Local delivery systems from an osteoconductive biomaterial are suggested as a promising strategy to avoid simultaneously peri-implant traumas and to induce tissue regeneration. In this work, it is detailed the design and construction of a multi-drug delivery formulation based on lipid membrane mimetic coated nano-hydroxyapatite, LMm/nano-HA, as a bone-specific drug delivery approach. The optimal LMm/nano-HA formulation was selected after analysing the lipid/nano-HA interaction by dynamic light scattering (DLS), ζ-potential, transmission electron microscopy (TEM), polarized optical microscopy (POM), differential scanning calorimetry (DSC) and UV-vis spectroscopy. After the initial screening, Ciprofloxacin and Ibuprofen simultaneous -load and -release efficiency from selected LMm/nano-HA was assessed. pH-responsive kinetic profiles of local drug distribution were characterized and compared with currently applied systemic doses. Finally, the systems' biocompatibility and drug released activity were positively validated. The obtained results demonstrated that LMm/nano-HA formulations can represent a valuable multi-modal platform in bone tissue therapies.


Asunto(s)
Materiales Biocompatibles , Sistemas de Liberación de Medicamentos , Durapatita , Lípidos , Membranas Artificiales , Nanopartículas , Animales , Antibacterianos/administración & dosificación , Antibacterianos/química , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/química , Materiales Biocompatibles/administración & dosificación , Materiales Biocompatibles/química , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Ciprofloxacina/administración & dosificación , Ciprofloxacina/química , Liberación de Fármacos , Durapatita/administración & dosificación , Durapatita/química , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Ibuprofeno/administración & dosificación , Ibuprofeno/química , Lípidos/administración & dosificación , Lípidos/química , Nanopartículas/administración & dosificación , Nanopartículas/química , Osteoblastos/efectos de los fármacos , Tamaño de la Partícula , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/crecimiento & desarrollo , Ratas Wistar , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo
12.
ACS Appl Mater Interfaces ; 10(23): 19534-19544, 2018 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-29799727

RESUMEN

Surface colonization competition between bacteria and host cells is one of the critical factors involved in tissue/implant integration. Current biomaterials are evaluated for their ability both of withstanding favorable responses of host tissue cells and of resisting bacterial contamination. In this work, the antibacterial ability of biocompatible Mg2+-substituted nanostructured hydroxyapatite (HA) was investigated. The densities of Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli strains were significantly decreased after culture in the presence of Mg-substituted HA materials in direct correlation with Mg2+-Ca2+ switch in the HA lattice. It was noticed that this decrease was accompanied by a minimal alteration of bacterial environments; therefore, the Mg2+-HA antibacterial effect was associated with the material surface topography and it electroactive behavior. It was observed that 2.23 wt % Mg2+-HA samples exhibited the best antibacterial performance; it decreased 2-fold the initial population of E. coli, P. aeruginosa, and S. aureus at the intermediate concentration (50 mg mL-1 of broth). Our results reinforce the potential of Mg-HA nanostructured materials to be used in antibacterial coatings for implantable devices and/or medicinal materials to prevent bone infection and to promote wound healing.


Asunto(s)
Osteomielitis , Antibacterianos , Antiinfecciosos , Materiales Biocompatibles Revestidos , Durapatita , Escherichia coli , Humanos , Magnesio , Pruebas de Sensibilidad Microbiana , Staphylococcus aureus
13.
Langmuir ; 34(7): 2471-2480, 2018 02 20.
Artículo en Inglés | MEDLINE | ID: mdl-29361824

RESUMEN

Bioceramic nanoparticles exhibit excellent features that enable them to function as an ideal material for hard tissue engineering. However, to fully understand their behavior, it is of crucial importance to understand their behavior within the fluids of the human body. To achieve this goal, we have studied the interaction between hydroxyapatite nanorods (HA) and bovine serum albumin (BSA). First, we describe the surface morphology of the nanoparticle. Then, the main characteristics of the physiological interplay of BSA and the hydroxyapatite nanoparticle are presented by using a battery of techniques: ITC, zeta potential, UV-vis, fluorescence, and CD. Experimental data was analyzed by developing specific approaches to determining important parameters such as rates, affinities, and stochiometries of protein associated with the nanoparticles. ITC has been confirmed as a powerful technique for determining the affinity, binding, and thermodynamics of BSA-nanoparticle interactions. Careful quantitative assessment of the kinetic properties of the adsorption were revealed by UV-vis and fluorescence measurements. Finally, CD measurements highlight the important role of protein flexibility in these kinds of systems.


Asunto(s)
Nanopartículas/química , Corona de Proteínas/química , Adsorción , Humanos , Unión Proteica , Corona de Proteínas/metabolismo , Albúmina Sérica Bovina/química , Albúmina Sérica Bovina/metabolismo , Espectrometría de Fluorescencia , Termodinámica
14.
ACS Appl Mater Interfaces ; 9(18): 15698-15710, 2017 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-28426935

RESUMEN

Ionic substitution can affect essential physicochemical properties leading to a specific biological behavior upon implantation. Therefore, it has been proposed as a tool to increase the biological efficiency of calcium phosphate based materials. In the following study, we have evaluated the contribution of an important cation in nature, Mg2+, into the structure of previously studied biocompatible and biodegradable hydroxyapatite (HA) nanorods and its subsequent effect on its chemical, morphology, and bone mimetic articulation. Mg2+-substituted HA samples were synthesized by an aqueous wet-chemical precipitation method, followed by an hydrothermal treatment involving a Mg2+ precursor that partially replace Ca2+ ions into HA crystal lattice; Mg2+ concentrations were modulated to obtain a nominal composition similar to that exists in calcified tissues. Hydrothermally synthesized Mg2+-substituted HA nanoparticles were characterized by X-ray powder diffraction, FT-NIR and EDX spectroscopies, field emission scanning and high resolution transmission electron microscopies (FE-SEM, H-TEM). Molecular modeling combining ab initio methods and power diffraction data were also performed. Results showed that Mg2+-substitution promoted the formation of calcium deficient HA (cdHA) where Mg2+ replacement is energetically favored at Ca(1) position in a limited and specific amount directing the additional Mg2+ toward the surface of the crystal. The control of Mg2+ incorporation into HA nanorods gave rise to a tailored crystallinity degree, cell parameters, morphology, surface hydration, solubility, and degradation properties in a dose-replacement dependent manner. The obtained materials show qualities that conjugated together to drive an optimal in vitro cellular viability, spreading, and proliferation confirming their biocompatibility. In addition, an improved adhesion of osteoblast was evidenced after Mg2+-Ca2+ substitution.

15.
J Colloid Interface Sci ; 494: 345-354, 2017 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-28161505

RESUMEN

The bioactivity of an implant is displayed on its ability to induce heterogeneous nucleation of biogenic apatite onto its surface upon immersion in body fluids; forming, through this layer, a stable bond with the host tissue. The present article evaluates the bioactivity of different nanostructured substrates based on synthetic hydroxyapatite (HA) and titania (TiO2) nanoparticles, where we extend the debate regarding the selective roles played by the presence of albumin on the biogenic apatite coating evolution. The substrates bone-bonding potential was evaluated by keeping the materials in contact with Simulated Body Fluid, while the influence of the presence of Bovine Serum Albumin in bioactivity was analyzed by a spectrophotometric technique. Our results show that materials' surface reactivity and their interfacial hydration are responsible for the bonding-site alteration and surface charge density distribution, which in turn, regulate the protein adsorption process. As a matter of fact, variations on the protein adsorbed density have a directly proportional impact on calcium binding sites, which should be responsible for the initiation of the mineralization process, disturbing the deposition of the interfacial calcium phosphate (Ca-P) mineralized coating.


Asunto(s)
Huesos/química , Durapatita/química , Nanopartículas/química , Albúmina Sérica Bovina/química , Adsorción , Líquidos Corporales/química , Calcificación Fisiológica , Fosfatos de Calcio/química , Humanos , Propiedades de Superficie , Titanio/química , Agua/química
16.
Curr Pharm Des ; 22(34): 5249-5256, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27174810

RESUMEN

The formation of liposomes, nanoparticle micelles, and related systems by mixtures of drugs and/or surfactants is of major relevance for the design of drug delivery systems. We can design new systems using different compounds. Traditionally these systems are created by trial and error using experimental data. However, in most cases measuring all the possible combinations represents a extensive work and almost always unaffordable. In this sense, we can use theoretical concepts and develop computational models to predict different physicochemical properties of self-aggregation processes of mixed molecular systems. In a previous work, we developed a new PT-LFER model (Linear Free Energy Relationships, LFER, combined with Perturbation Theory, PT, ideas) for binary systems. The best PT-LFER model found predicted the effects of 25000 perturbations over nine different properties of binary systems. The present work has two parts. Firstly, we carry out an analysis on the new results on the applications and experimental-theoretical studies of binary selfassembled systems. In the second part, we report for the first time, a new experimental-theoretic study of the NaDC-DTAB binary system. For this purpose, we have combined experimental procedures plus physicochemical thermodynamic framework with the PT-LFER model reported in our previous work.


Asunto(s)
Simulación de Dinámica Molecular , Termodinámica , Método de Montecarlo
17.
Curr Pharm Des ; 22(34): 5211-5220, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27174813

RESUMEN

BACKGROUND: Understanding the physicochemical basis and the different models of nanosystems is nowadays fundamental in a great number of scientific areas and industrial processes. RESULTS: Here, we focus on nanosystems created by self-assembly, molecular or inorganic. The organization of single units at these scales is a challenging matter in light of the inherently small dimensions involved, the sensitivity of the system to small perturbations, and the problem of scaling up such a process for widespread use and implementation. CONCLUSION: This review examines the different self-assembly routes used to create nanostructures in both the equilibrium and non-equilibrium/dynamic systems and discusses their limits and applications. The connection to biomedicine and pharmaceutical design has been emphasized.


Asunto(s)
Investigación Biomédica , Modelos Químicos , Nanoestructuras/química , Nanotecnología , Humanos , Termodinámica
18.
Colloids Surf B Biointerfaces ; 145: 382-391, 2016 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-27220014

RESUMEN

Intrinsic material skills have a deep effect on the mechanical and biological performance of bone substitutes, as well as on its associated biodegradation properties. In this work we have manipulated the preparation of collagenous derived fiber mesh frameworks to display a specific composition, morphology, open macroporosity, surface roughness and permeability characteristics. Next, the effect of the induced physicochemical attributes on the scaffold's mechanical behavior, bone bonding potential and biodegradability were evaluated. It was found that the scaffold microstructure, their inherent surface roughness, and the compression strength of the gelatin scaffolds can be modulated by the effect of the cross-linking agent and, essentially, by mimicking the nano-scale size of hydroxyapatite in natural bone. A clear effect of bioactive hydroxyapatite nano-rods on the scaffolds skills can be appreciated and it is greater than the effect of the cross-linking agent, offering a huge perspective for the upcoming progress of bone implant technology.


Asunto(s)
Biomimética/métodos , Durapatita/química , Gelatina/química , Andamios del Tejido/química , Nanotubos/química , Taninos/química , Ingeniería de Tejidos
19.
Biochim Biophys Acta ; 1860(2): 452-64, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26656883

RESUMEN

BACKGROUND: Cerium oxide (CeO2) and Ce-doped nanostructured materials (NMs) are being seen as innovative therapeutic tools due to their exceptional antioxidant effects; nevertheless their bio-applications are still in their infancy. METHODS: TiO2, Ce-TiO2 and CeO2-TiO2 NMs were synthesized by a bottom-up microemulsion-mediated strategy and calcined during 7h at 650°C under air flux. The samples were compared to elucidate the physicochemical characteristics that determine cellular uptake, toxicity and the influence of redox balance between the Ce(3+)/Ce(4+) on the cytoprotective role against an exogenous ROS source: H2O2. Fibroblasts were selected as a cell model because of their participation in wound healing and fibrotic diseases. RESULTS: Ce-TiO2 NM obtained via sol-gel reaction chemistry of metallic organic precursors exerts a real cytoprotective effect against H2O2 over fibroblast proliferation, while CeO2 pre-formed nanoparticles incorporated to TiO2 crystalline matrix lead to a harmful CeO2-TiO2 material. TiO2 was processed by the same pathways as Ce-TiO2 and CeO2-TiO2 NM but did not elicit any adverse or protective influence compared to controls. CONCLUSIONS: It was found that the Ce atoms source and its concentration have a clear effect on material's physicochemical properties and its subsequent influence in the cellular response. It can induce a range of biological reactions that vary from cytotoxic to cytoprotective. GENERAL SIGNIFICANCE: Even though there are still some unresolved issues and challenges, the unique physical and chemical properties of Ce-based NMs are fascinating and versatile resources for different biomedical applications.


Asunto(s)
Cerio/farmacología , Citoprotección , Fibroblastos/efectos de los fármacos , Peróxido de Hidrógeno/toxicidad , Nanoestructuras , Titanio/farmacología , Animales , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Ratones
20.
Langmuir ; 31(44): 12009-18, 2015 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-26484726

RESUMEN

Studies of the self-aggregation of binary systems are of both theoretical and practical importance. They provide an opportunity to investigate the influence of the molecular structure of the hydrophobe on the nonideality of mixing. On the other hand, linear free energy relationship (LFER) models, such as Hansch's equations, may be used to predict the properties of chemical compounds such as drugs or surfactants. However, the task becomes more difficult once we want to predict simultaneaously the effect over multiple output properties of binary systems of perturbations under multiple input experimental boundary conditions (b(j)). As a consequence, we need computational chemistry or chemoinformatics models that may help us to predict different properties of the autoaggregation process of mixed surfactants under multiple conditions. In this work, we have developed the first model that combines perturbation theory (PT) and LFER ideas. The model uses as input covariance PT operators (CPTOs). CPTOs are calculated as the difference between covariance ΔCov((i)µ(k)) functions before and after multiple perturbations in the binary system. In turn, covariances calculated as the product of two Box-Jenkins operators (BJO) operators. BJOs are used to measure the deviation of the structure of different chemical compounds from a set of molecules measured under a given subset of experimental conditions. The best CPT-LFER model found predicted the effects of 25,000 perturbations over 9 different properties of binary systems. We also reported experimental studies of different experimental properties of the binary system formed by sodium glycodeoxycholate and didodecyldimethylammonium bromide (NaGDC-DDAB). Last, we used our CPT-LFER model to carry out a 1000 data point simulation of the properties of the NaGDC-DDAB system under different conditions not studied experimentally.

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