Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 73
Filtrar
1.
Molecules ; 29(11)2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38893294

RESUMEN

Organic-inorganic hybrids represent a good solution to improve the solubility and dissolution rates of poorly soluble drugs whose number has been increasing in the last few years. One of the most diffused inorganic matrices is hydroxyapatite (HAP), which is a biocompatible and osteoconductive material. However, the understanding of the hybrids' functioning mechanisms is in many cases limited; thus, thorough physicochemical characterizations are needed. In the present paper, we prepared hybrids of pure and Mg-doped hydroxyapatite with meloxicam, a drug pertaining to the Biopharmaceutical Classification System (BCS) class II, i.e., drugs with low solubility and high permeability. The hybrids' formation was demonstrated by FT-IR, which suggested electrostatic interactions between HAP and drug. The substitution of Mg in the HAP structure mainly produced a structural disorder and a reduction in crystallite sizes. The surface area of HAP increased after Mg doping from 82 to 103 m2g-1 as well as the pore volume, justifying the slightly high drug amount adsorbed by the Mg hybrid. Notwithstanding the low drug loading on the hybrids, the solubility, dissolution profiles and wettability markedly improved with respect to the drug alone, particularly for the Mg doped one, which was probably due to the main distribution of the drug on the HAP surface.

2.
Molecules ; 29(8)2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38675544

RESUMEN

Scientific and industrial reasons dictate the study of the solid state of imepitoin, a highly safe and tolerable anticonvulsant drug used in the therapy of epileptic dogs that was approved in the Europe Union in 2013. Our investigations allowed us to discover the existence of a new polymorph of imepitoin, which finds itself in a monotropic relationship with the crystalline form (polymorph I) already known and present on the market. This form (polymorph II), obtained by crystallization from xylene, remains metastable under ambient conditions for at least 1 year. Both solid forms were characterized by thermal (DSC and TGA), spectroscopic (FT-IR and Raman), microscopic (SEM and HSM), and diffractometric techniques. The thermodynamic relationship between the two polymorphs (monotropic) is such that it is not possible to study the melting of polymorph II, not even by adopting appropriate experimental strategies. Our measurements highlighted that the melting peak of imepitoin actually also includes an onset of melt decomposition. The ab initio structure solution, obtained from synchrotron X-ray powder diffraction data collected at room temperature, allowed us to determine the crystal structure of the new polymorph (II). It crystallizes in the monoclinic crystal structure, P21/c space group (#14), with a = 14.8687(6) Å, b = 7.2434(2) Å, c = 12.5592(4) Å, ß = 107.5586(8)°, V = 1289.61(8) Å3, and Z = 4.

3.
Molecules ; 29(8)2024 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-38675705

RESUMEN

The NASICON-structured Na3MnZr(PO4)3 compound is a promising high-voltage cathode material for sodium-ion batteries (SIBs). In this study, an easy and scalable electrospinning approach was used to synthesize self-standing cathodes based on Na3MnZr(PO4)3 loaded into carbon nanofibers (CNFs). Different strategies were applied to load the active material. All the employed characterization techniques (X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), thermal gravimetric analysis (TGA), and Raman spectroscopy) confirmed the successful loading. Compared to an appositely prepared tape-cast electrode, Na3MnZr(PO4)3/CNF self-standing cathodes demonstrated an enhanced specific capacity, especially at high C-rates, thanks to the porous conducive carbon nanofiber matrix. Among the strategies applied to load Na3MnZr(PO4)3 into the CNFs, the electrospinning (vertical setting) of the polymeric solution containing pre-synthesized Na3MnZr(PO4)3 powders resulted effective in obtaining the quantitative loading of the active material and a homogeneous distribution through the sheet thickness. Notably, Na3MnZr(PO4)3 aggregates connected to the CNFs, covered their surface, and were also embedded, as demonstrated by TEM and EDS. Compared to the self-standing cathodes prepared with the horizontal setting or dip-drop coating methods, the vertical binder-free electrode exhibited the highest capacity values of 78.2, 55.7, 38.8, 22.2, 16.2, 12.8, 10.3, 9.0, and 8.5 mAh/g at C-rates of 0.05C, 0.1C, 0.2C, 0.5C, 1C, 2C, 5C, 10C, and 20C, respectively, with complete capacity retention at the end of the measurements. It also exhibited a good cycling life, compared to its tape-cast counterpart: it displayed higher capacity retention at 0.2C and 1C, and, after cycling 1000 cycles at 1C, it could be further cycled at 5C, 10C, and 20C.

4.
Int J Mol Sci ; 24(15)2023 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-37569489

RESUMEN

Vascular graft infections are a severe complication in vascular surgery, with a high morbidity and mortality. Prevention and treatment involve the use of antibiotic- or antiseptic-impregnated artificial vascular grafts, but currently, there are no commercially available infection-proof small-diameter vascular grafts (SDVGs). In this work we investigated the antimicrobic activity of two SDVGs prototypes loaded with tobramycin and produced via the electrospinning of drug-doped PLGA (polylactide-co-glycolide) solutions. Differences in rheological and conductivity properties of the polymer solutions resulted in non-identical fibre morphology that deeply influenced the hydration profile and consequently the in vitro cumulative drug release, which was investigated by using a spectrofluorimetric technique. Using DDSolver Excel add-in, modelling of the drug release kinetic was performed to evaluate the release mechanism involved: Prototype 1 showed a sustained and diffusive driven drug release, which allowed for the complete elution of tobramycin within 2 weeks, whereas Prototype 2 resulted in a more extended drug release controlled by both diffusion and matrix relaxation. Time-kill assays performed on S. aureus and E. coli highlighted the influence of burst drug release on the decay rate of bacterial populations, with Prototype 1 being more efficient on both microorganisms. Nevertheless, both prototypes showed good antimicrobic activity over the 5 days of in vitro testing.

5.
Molecules ; 28(10)2023 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-37241774

RESUMEN

The search for effective systems to facilitate the release of poorly bioavailable drugs is a forefront topic for the pharmaceutical market. Materials constituted by inorganic matrices and drugs represent one of the latest research strategies in the development of new drug alternatives. Our aim was to obtain hybrid nanocomposites of Tenoxicam, an insoluble nonsteroidal anti-inflammatory drug, with both layered double hydroxides (LDHs) and hydroxyapatite (HAP). The physicochemical characterization on the base of X-ray powder diffraction, SEM/EDS, DSC and FT-IR measurements was useful to verify the possible hybrids formation. In both cases, the hybrids formed, but it seemed that the drug intercalation in LDH was low and, in fact, the hybrid was not effective in improving the pharmacokinetic properties of the drug alone. On the contrary, the HAP-Tenoxicam hybrid, compared to the drug alone and to a simple physical mixture, showed an excellent improvement in wettability and solubility and a very significant increase in the release rate in all the tested biorelevant fluids. It delivers the entire daily dose of 20 mg in about 10 min.


Asunto(s)
Hidróxidos , Nanocompuestos , Espectroscopía Infrarroja por Transformada de Fourier , Hidróxidos/química , Nanocompuestos/química , Hidroxiapatitas
6.
Molecules ; 28(8)2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-37110635

RESUMEN

Carvedilol is a poorly water-soluble drug employed to treat chronic heart failure. In this study, we synthesize new carvedilol-etched halloysite nanotubes (HNTs) composites to enhance solubility and dissolution rate. The simple and feasible impregnation method is used for carvedilol loading (30-37% weight). Both the etched HNTs (acidic HCl and H2SO4 and alkaline NaOH treatments) and the carvedilol-loaded samples are characterized by various techniques (XRPD, FT-IR, solid-state NMR, SEM, TEM, DSC, and specific surface area). The etching and loading processes do not induce structural changes. The drug and carrier particles are in intimate contact and their morphology is preserved, as demonstrated by TEM images. The 27Al and 13C solid-state NMR and FT-IR findings show that carvedilol interactions involve the external siloxane surface, especially the aliphatic carbons, the functional groups, and, by inductive effect, the adjacent aromatic carbons. All the carvedilol-halloysite composites display enhanced dissolution rate, wettability, and solubility, as compared to carvedilol. The best performances are obtained for the carvedilol-halloysite system based on HNTs etched with HCl 8M, which exhibits the highest value of specific surface area (91 m2 g-1). The composites make the drug dissolution independent of the environmental conditions of the gastrointestinal tract and its absorption less variable, more predictable, and independent from the pH of the medium.


Asunto(s)
Nanotubos , Carvedilol/química , Solubilidad , Arcilla , Espectroscopía Infrarroja por Transformada de Fourier , Nanotubos/química
7.
Int J Mol Sci ; 23(13)2022 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-35806083

RESUMEN

Polyetheretherketone (PEEK) titanium composite (PTC) is a novel interbody fusion device that combines a PEEK core with titanium alloy (Ti6Al4V) endplates. The present study aimed to investigate the in vitro biological reactivity of human bone-marrow-derived mesenchymal stem cells (hBM-MSCs) to micro- and nanotopographies produced by an acid-etching process on the surface of 3D-printed PTC endplates. Optical profilometer and scanning electron microscopy were used to assess the surface roughness and identify the nano-features of etched or unetched PTC endplates, respectively. The viability, morphology and the expression of specific osteogenic markers were examined after 7 days of culture in the seeded cells. Haralick texture analysis was carried out on the unseeded endplates to correlate surface texture features to the biological data. The acid-etching process modified the surface roughness of the 3D-printed PTC endplates, creating micro- and nano-scale structures that significantly contributed to sustaining the viability of hBM-MSCs and triggering the expression of early osteogenic markers, such as alkaline phosphatase activity and bone-ECM protein production. Finally, the topography of 3D-printed PTC endplates influenced Haralick's features, which in turn correlated with the expression of two osteogenic markers, osteopontin and osteocalcin. Overall, these data demonstrate that the acid-etching process of PTC endplates created a favourable environment for osteogenic differentiation of hBM-MSCs and may potentially have clinical benefit.


Asunto(s)
Células Madre Mesenquimatosas , Osteogénesis , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Humanos , Cetonas/metabolismo , Células Madre Mesenquimatosas/metabolismo , Polietilenglicoles/metabolismo , Impresión Tridimensional , Propiedades de Superficie , Titanio/metabolismo
8.
Int J Mol Sci ; 22(24)2021 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-34948352

RESUMEN

Peripheral artery occlusive disease is an emerging cardiovascular disease characterized by the blockage of blood vessels in the limbs and is associated with dysfunction, gangrene, amputation, and a high mortality risk. Possible treatments involve by-pass surgery using autologous vessel grafts, because of the lack of suitable synthetic small-diameter vascular prosthesis. One to five percent of patients experience vascular graft infection, with a high risk of haemorrhage, spreading of the infection, amputation and even death. In this work, an infection-proof vascular graft prototype was designed and manufactured by electrospinning 12.5% w/v poly-L-lactic-co-glycolic acid solution in 75% v/v dichloromethane, 23.8% v/v dimethylformamide and 1.2% v/v water, loaded with 0.2% w/wPLGA. Polymer and tobramycin concentrations were selected after viscosity and surface tension and after HPLC-UV encapsulation efficiency (EE%) evaluation, respectively. The final drug-loaded prototype had an EE% of 95.58% ± 3.14%, with smooth fibres in the nanometer range and good porosity; graft wall thickness was 291 ± 20.82 µm and its internal diameter was 2.61 ± 0.05 mm. The graft's antimicrobic activity evaluation through time-kill assays demonstrated a significant and strong antibacterial activity over 5 days against Staphylococcus aureus and Escherichia coli. An indirect cell viability assay on Normal Human Dermal Fibroblasts (NHDF) confirmed the cytocompatibility of the grafts.


Asunto(s)
Antibacterianos/administración & dosificación , Prótesis Vascular , Sistemas de Liberación de Medicamentos , Tobramicina/administración & dosificación , Antibacterianos/química , Antibacterianos/farmacología , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos/instrumentación , Liberación de Fármacos , Escherichia coli/efectos de los fármacos , Infecciones por Escherichia coli/tratamiento farmacológico , Humanos , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/química , Infecciones Estafilocócicas/prevención & control , Staphylococcus aureus/efectos de los fármacos , Tobramicina/química , Tobramicina/farmacología , Injerto Vascular
9.
Molecules ; 26(11)2021 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-34073973

RESUMEN

The present work is a concrete example of how physico-chemical studies, if performed in depth, are crucial to understand the behavior of pharmaceutical solids and constitute a solid basis for the control of the reproducibility of the industrial batches. In particular, a deep study of the thermal behavior of glipizide, a hypoglycemic drug, was carried out with the aim of clarifying whether the recognition of its polymorphic forms can really be done on the basis of the endothermic peak that the literature studies attribute to the melting of the compound. A number of analytical techniques were used: thermal techniques (DSC, TGA), X-ray powder diffraction (XRPD), FT-IR spectroscopy and scanning electron microscopy (SEM). Great attention was paid to the experimental design and to the interpretation of the combined results obtained by all these techniques. We proved that the attribution of the endothermic peak shown by glipizide to its melting was actually wrong. The DSC peak is no doubt triggered by a decomposition process that involves gas evolution (cyclohexanamine and carbon dioxide) and formation of 5-methyl-N-[2-(4-sulphamoylphenyl) ethyl] pyrazine-2-carboxamide, which remains as decomposition residue. Thermal treatments properly designed and the combined use of DSC with FT-IR and XRPD led to identifying a new polymorphic form of 5-methyl-N-[2-(4-sulphamoylphenyl) ethyl] pyrazine-2-carboxamide, which is obtained by crystallization from the melt. Hence, our results put into evidence that the check of the polymorphic form of glipizide cannot be based on the temperature values of the DSC peak, since such a peak is due to a decomposition process whose Tonset value is strongly affected by the particle size. Kinetic studies of the decomposition process show the high stability of solid glipizide at room temperature.


Asunto(s)
Glipizida/química , Hipoglucemiantes/química , Rastreo Diferencial de Calorimetría , Microscopía Electrónica de Rastreo , Difracción de Polvo , Espectroscopía Infrarroja por Transformada de Fourier , Termogravimetría
10.
Biomacromolecules ; 21(3): 1157-1170, 2020 03 09.
Artículo en Inglés | MEDLINE | ID: mdl-32011862

RESUMEN

Regulating stem cell adhesion and growth onto functionalized biomaterial scaffolds is an important issue in the field of tissue engineering and regenerative medicine. In this study, new electrospun scaffolds of poly(l-lactic acid) (PLLA), as bioresorbable polymer, and ß-lactam compounds agonists of selected integrins, as functional components with cell adhesive properties, are designed. The new ß-lactam-PLLA scaffolds contribute significantly in guiding protein translation involved in human bone marrow mesenchymal stem cells (hBM-MSC) adhesion and integrin gene expression. Scanning electron microscopy, confocal laser scanning microscopy, and Western Blot analyses reveal that GM18-PLLA shows the best results, promoting cell adhesion by significantly driving changes in focal adhesion proteins distribution (ß1 integrin and vinculin) and activation (pFAK), with a notable increase of GM18-targets subunits integrin gene expression, α4 and ß1. These novel functionalized submicrometric fibrous scaffolds demonstrate, for the first time, the powerful combination of selective ß-lactams agonists of integrins with biomimetic scaffolds, suggesting a designed rule that could be suitably applied to tissue repair and regeneration.


Asunto(s)
Células Madre Mesenquimatosas , Nanofibras , Adhesión Celular , Diferenciación Celular , Proliferación Celular , Humanos , Integrinas , Ácido Láctico , Poliésteres , Ingeniería de Tejidos , Andamios del Tejido , beta-Lactamas/farmacología
11.
Int J Mol Sci ; 21(5)2020 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-32143536

RESUMEN

Aim of work was to locate a simple, reproducible protocol for uniform seeding and optimal cellularization of biodegradable patch minimizing the risk of structural damages of patch and its contamination in long-term culture. Two seeding procedures are exploited, namely static seeding procedures on biodegradable and biocompatible patches incubated as free floating (floating conditions) or supported by CellCrownTM insert (fixed conditions) and engineered by porcine bone marrow MSCs (p-MSCs). Scaffold prototypes having specific structural features with regard to pore size, pore orientation, porosity, and pore distribution were produced using two different techniques, such as temperature-induced precipitation method and electrospinning technology. The investigation on different prototypes allowed achieving several implementations in terms of cell distribution uniformity, seeding efficiency, and cellularization timing. The cell seeding protocol in stating conditions demonstrated to be the most suitable method, as these conditions successfully improved the cellularization of polymeric patches. Furthermore, the investigation provided interesting information on patches' stability in physiological simulating experimental conditions. Considering the in vitro results, it can be stated that the in vitro protocol proposed for patches cellularization is suitable to achieve homogeneous and complete cellularizations of patch. Moreover, the protocol turned out to be simple, repeatable, and reproducible.


Asunto(s)
Materiales Biocompatibles/química , Esófago/patología , Esófago/cirugía , Células Madre Mesenquimatosas/citología , Ingeniería de Tejidos/métodos , Animales , Células de la Médula Ósea/citología , Proliferación Celular , Supervivencia Celular , Células Cultivadas , Microscopía Electrónica de Rastreo , Poliésteres/química , Porosidad , Porcinos , Temperatura , Andamios del Tejido/química
12.
Int J Mol Sci ; 20(12)2019 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-31238568

RESUMEN

An electrospinning process was optimized to produce fibers of micrometric size with different combinations of polymeric and surfactant materials to promote the dissolution rate of an insoluble drug: firocoxib. Scanning Electron Microscopy (SEM) showed that only some combinations of the proposed carrier systems allowed the production of suitable fibers and further fine optimization of the technique is also needed to load the drug. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD) suggest that the drug is in an amorphous state in the final product. Drug amorphization, the fine dispersion of the active in the carriers, and the large surface area exposed to water interaction obtained through the electrospinning process can explain the remarkable improvement in the dissolution performance of firocoxib from the final product developed.


Asunto(s)
4-Butirolactona/análogos & derivados , Inhibidores de la Ciclooxigenasa 2/administración & dosificación , Inhibidores de la Ciclooxigenasa 2/química , Portadores de Fármacos , Nanofibras , Polímeros , Sulfonas/administración & dosificación , Sulfonas/química , Tensoactivos , 4-Butirolactona/administración & dosificación , 4-Butirolactona/química , Portadores de Fármacos/química , Nanofibras/química , Nanofibras/ultraestructura , Polímeros/química , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier , Tensoactivos/química , Termodinámica
13.
Biomacromolecules ; 19(7): 2618-2628, 2018 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-29584947

RESUMEN

The dispersion of nanoparticles having different size-, shape-, and composition-dependent properties is an exciting approach to design and synthesize multifunctional materials and devices. This work shows a detailed investigation of the preparation and properties of free-standing nanocomposite films based on cellulose nanocrystals (CNC) loaded with three different types of metal nanoparticles. CNC-based nanocomposites having zinc oxide (ZnO), titanium dioxide (TiO2), and silver oxide (Ag2O) have been obtained through evaporation-induced self-assembly (EISA) in acqueous solution. Morphological and optical characteristics, chemical properties, wettability, and antimicrobial assays of the produced films were conducted. Furthermore, disintegrability in composting condition of CNC based nanocomposites was here investigated for the first time. The morphological observations revealed the formation of a chiral nematic structure with uniformly distributed nanoparticles. The bionanocomposite films based on the metal nanoparticles had effective antimicrobial activity, killing both Escherichia coli RB ( E. coli RB) and Staphylococcus aureus 8325-4 ( S. aureus 8325-4). The simplicity method of film preparation, the large quantity of cellulose in the world, and the free-standing nature of the nanocomposite films offer highly advantageous characteristics that can for the new development of multifunctional materials.


Asunto(s)
Antibacterianos/química , Celulosa/análogos & derivados , Nanopartículas del Metal/química , Nanopartículas/química , Antibacterianos/farmacología , Escherichia coli , Óxidos/química , Compuestos de Plata/química , Staphylococcus aureus/efectos de los fármacos , Titanio/química , Óxido de Zinc/química
14.
Drug Dev Ind Pharm ; 44(2): 243-250, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28956461

RESUMEN

OBJECTIVE: To improve the pharmaceutical behavior of the oral antidiabetic agent gliclazide through the synthesis of multicomponent crystals with tromethamine. METHODS: Multicomponent crystals were prepared by solvent evaporation method, kneading, and combining mechanical and thermal activation. DSC, FT-IR spectroscopy, X-ray diffraction, SEM-EDS, and SSNMR were used to investigate their formation. Measurements of solubility and dissolution rate were carried out for the pharmaceutical characterization. RESULTS: The formation of multicomponent crystals of gliclazide and tromethamine was confirmed by all the techniques. In particular, FT-IR and NMR measurements revealed that the interaction between drug and coformer leads to significant changes of the hydrogen bond scheme, and that almost all the functional groups of the two molecules are involved. The dissolution profile of the new phase is significantly better than that of both pure gliclazide and of the reference commercial product Diabrezide®. CONCLUSIONS: The new system shows an improved pharmaceutical behavior and could be formulated in a dosage form to obtain a rapid and complete release of the drug available for absorption.


Asunto(s)
Gliclazida/química , Tecnología Farmacéutica/métodos , Trometamina/química , Rastreo Diferencial de Calorimetría , Cristalografía por Rayos X , Análisis Diferencial Térmico , Liberación de Fármacos , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Difracción de Polvo , Espectroscopía Infrarroja por Transformada de Fourier
15.
Int J Mol Sci ; 19(10)2018 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-30336625

RESUMEN

We report the study of novel biodegradable electrospun scaffolds from poly(butylene 1,4-cyclohexandicarboxylate-co-triethylene cyclohexanedicarboxylate) (P(BCE-co-TECE)) as support for in vitro and in vivo muscle tissue regeneration. We demonstrate that chemical composition, i.e., the amount of TECE co-units (constituted of polyethylene glycol-like moieties), and fibre morphology, i.e., aligned microfibrous or sub-microfibrous scaffolds, are crucial in determining the material biocompatibility. Indeed, the presence of ether linkages influences surface wettability, mechanical properties, hydrolytic degradation rate, and density of cell anchoring points of the studied materials. On the other hand, electrospun scaffolds improve cell adhesion, proliferation, and differentiation by favouring cell alignment along fibre direction (fibre morphology), also allowing for better cell infiltration and oxygen and nutrient diffusion (fibre size). Overall, C2C12 myogenic cells highly differentiated into mature myotubes when cultured on microfibres realised with the copolymer richest in TECE co-units (micro-P73 mat). Lastly, when transplanted in the tibialis anterior muscles of healthy, injured, or dystrophic mice, micro-P73 mat appeared highly vascularised, colonised by murine cells and perfectly integrated with host muscles, thus confirming the suitability of P(BCE-co-TECE) scaffolds as substrates for skeletal muscle tissue engineering.


Asunto(s)
Ciclohexanos/química , Músculo Esquelético/fisiología , Oxígeno/química , Polienos/química , Polietilenglicoles/química , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Animales , Diferenciación Celular , Línea Celular , Proliferación Celular , Forma de la Célula , Implantes Experimentales , Inflamación/patología , Antígeno Ki-67/metabolismo , Masculino , Ratones Endogámicos C57BL , Neovascularización Fisiológica
16.
Blood ; 125(14): 2254-64, 2015 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-25575540

RESUMEN

We present a programmable bioengineered 3-dimensional silk-based bone marrow niche tissue system that successfully mimics the physiology of human bone marrow environment allowing us to manufacture functional human platelets ex vivo. Using stem/progenitor cells, megakaryocyte function and platelet generation were recorded in response to variations in extracellular matrix components, surface topography, stiffness, coculture with endothelial cells, and shear forces. Millions of human platelets were produced and showed to be functional based on multiple activation tests. Using adult hematopoietic progenitor cells our system demonstrated the ability to reproduce key steps of thrombopoiesis, including alterations observed in diseased states. A critical feature of the system is the use of natural silk protein biomaterial allowing us to leverage its biocompatibility, nonthrombogenic features, programmable mechanical properties, and surface binding of cytokines, extracellular matrix components, and endothelial-derived proteins. This in turn offers new opportunities for the study of blood component production ex vivo and provides a superior tissue system for the study of pathologic mechanisms of human platelet production.


Asunto(s)
Plaquetas/citología , Células de la Médula Ósea/citología , Células Madre Hematopoyéticas/citología , Megacariocitos/citología , Mielofibrosis Primaria/patología , Seda/química , Andamios del Tejido/química , Adulto , Animales , Plaquetas/metabolismo , Bombyx , Células de la Médula Ósea/metabolismo , Células Cultivadas , Técnicas de Cocultivo , Endotelio Vascular/citología , Endotelio Vascular/metabolismo , Matriz Extracelular , Citometría de Flujo , Células Madre Hematopoyéticas/metabolismo , Humanos , Megacariocitos/metabolismo , Mielofibrosis Primaria/metabolismo , Trombopoyesis/fisiología , Ingeniería de Tejidos
17.
AAPS PharmSciTech ; 16(5): 1129-39, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25700978

RESUMEN

A stability study was performed on ivermectin (IVM)-loaded biodegradable microparticles intended for injection in dogs. The rational was to evaluate the performances upon irradiation of a drug, such as IVM, with a few criticalities with respect to its stability, and toxicity. The goal was to provide valuable information for pharmaceutical scientists and manufacturers working in the veterinary area. The microspheres based on poly(D,L-lactide) and poly-(ε-caprolactone) and loaded with IVM and with the addition of alpha-tocopherol (TCP) as antioxidant were prepared by the emulsion solvent evaporation method and sterilized by gamma irradiation. Microsphere characterization in term of size, shape, polymer, and IVM stability upon irradiation was performed. The results show that the type of polymer significantly affects microsphere characteristics and performances. Moreover, suitably stable formulations can be achieved only by TCP addition.


Asunto(s)
Antiparasitarios/química , Portadores de Fármacos , Ivermectina/química , Poliésteres/química , Drogas Veterinarias/química , Antioxidantes/química , Antiparasitarios/efectos de la radiación , Composición de Medicamentos , Estabilidad de Medicamentos , Excipientes/química , Rayos gamma , Ivermectina/efectos de la radiación , Microesferas , Modelos Químicos , Solubilidad , Drogas Veterinarias/efectos de la radiación , alfa-Tocoferol/química
18.
AAPS PharmSciTech ; 15(1): 75-82, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24146118

RESUMEN

Tridimensional scaffolds can promote bone regeneration as a framework supporting the migration of cells from the surrounding tissue into the damaged tissue and as delivery systems for the controlled or prolonged release of cells, genes, and growth factors. The goal of the work was to obtain an advanced medical device for bone regeneration through coating a decellularized and deproteinized bone matrix of bovine origin with a biodegradable, biocompatible polymer, to improve the cell engraftment on the bone graft. The coating protocol was studied and set up to obtain a continuous and homogeneous polylactide-co-glycolide (PLGA) coating on the deproteinized bone matrix Orthoss® block without occluding pores and decreasing the scaffold porosity. The PLGA-coated scaffolds were characterized for their morphology and porosity. The effects of PLGA polymer coating on cell viability were assessed with the 3-(4,5-dimethyl-2-thiazolyl)-2,5 diphenyl-2H-tetrazolium assay. The polymer solution concentration and the number of polymeric layers were the main variables affecting coating efficiency and porosity of the original decellularized bone matrix. The designed polymer coating protocol did not affect the trabecular structure of the original decellularized bone matrix. The PLGA-coated decellularized bone matrix maintained the structural features, and it improved the ability in stimulating fibroblasts attachment and proliferation.


Asunto(s)
Regeneración Ósea/fisiología , Equipos y Suministros , Ingeniería de Tejidos/instrumentación , Andamios del Tejido/química , Implantes Absorbibles , Matriz Ósea/química , Matriz Ósea/fisiología , Células Cultivadas , Materiales Biocompatibles Revestidos/química , Fibroblastos/fisiología , Humanos , Ácido Láctico/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Polímeros/química , Porosidad , Ingeniería de Tejidos/métodos
19.
Nanomaterials (Basel) ; 14(1)2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38202568

RESUMEN

Poorly water-soluble drugs represent a challenge for the pharmaceutical industry because it is necessary to find properly tuned and efficient systems for their release. In this framework, organic-inorganic hybrid systems could represent a promising strategy. A largely diffused inorganic host is hydroxyapatite (HAP, Ca10(PO4)6(OH)2), which is easily synthesized with different external forms and can adsorb different kinds of molecules, thereby allowing rapid drug release. Hybrid nanocomposites of HAP nanorods, obtained through hydrothermal synthesis, were prepared with two model pharmaceutical molecules characterized by low and pH-dependent solubility: meloxicam, a non-steroidal anti-inflammatory drug, and bumetanide, a diuretic drug. Both hybrids were physically and chemically characterized through the combined use of X-ray powder diffraction, scanning electron microscopy with energy-dispersive spectroscopy, differential scanning calorimetry, and infrared spectroscopy measurements. Then, their dissolution profiles and hydrophilicity (contact angles) in different media as well as their solubility were determined and compared to the pure drugs. This hybrid system seems particularly suitable as a drug carrier for bumetanide, as it shows higher drug loading and good dissolution profiles, while is less suitable for meloxicam, an acid molecule.

20.
Nanomaterials (Basel) ; 14(9)2024 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-38727398

RESUMEN

Self-standing Na3MnTi(PO4)3/carbon nanofiber (CNF) electrodes are successfully synthesized by electrospinning. A pre-synthesized Na3MnTi(PO4)3 is dispersed in a polymeric solution, and the electrospun product is heat-treated at 750 °C in nitrogen flow to obtain active material/CNF electrodes. The active material loading is 10 wt%. SEM, TEM, and EDS analyses demonstrate that the Na3MnTi(PO4)3 particles are homogeneously spread into and within CNFs. The loaded Na3MnTi(PO4)3 displays the NASICON structure; compared to the pre-synthesized material, the higher sintering temperature (750 °C) used to obtain conductive CNFs leads to cell shrinkage along the a axis. The electrochemical performances are appealing compared to a tape-casted electrode appositely prepared. The self-standing electrode displays an initial discharge capacity of 124.38 mAh/g at 0.05C, completely recovered after cycling at an increasing C-rate and a coulombic efficiency ≥98%. The capacity value at 20C is 77.60 mAh/g, and the self-standing electrode exhibits good cycling performance and a capacity retention of 59.6% after 1000 cycles at 1C. Specific capacities of 33.6, 22.6, and 17.3 mAh/g are obtained by further cycling at 5C, 10C, and 20C, and the initial capacity is completely recovered after 1350 cycles. The promising capacity values and cycling performance are due to the easy electrolyte diffusion and contact with the active material, offered by the porous nature of non-woven nanofibers.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA