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1.
Int J Pharm ; 655: 124058, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38552754

RESUMEN

Polypharmacy is a common issue, especially among elderly patients resulting in administration errors and patient inconvenience. Hypertension is a prevalent health condition that frequently leads to polypharmacy, as its treatment typically requires the co-administration of more than one different Active Pharmaceutical Ingredients (API's). To address these issues, floating hollow torus-shaped dosage forms were developed, aiming at providing prolonged gastric retention and sustained drug release. The dosage forms (polypills) containing three anti-hypertensive API's (diltiazem (DIL), propranolol (PRP) and hydrochlorothiazide (HCTZ)) were created via Fused Deposition Modelling 3D printing. A multitude of the dosage forms were loaded into a capsule and the resulting formulation achieved prolonged retention times over a 12-hour period in vitro, by leveraging both the buoyancy of the dosage forms, and the "cheerios effect" that facilitates the aggregation and retention of the dosage forms via a combination of surface tension and shape of the objects. Physicochemical characterization methods and imaging techniques were employed to investigate the properties and the internal and external structure of the dosage forms. Furthermore, an ex vivo porcine stomach model revealed substantial aggregation, adhesion and retention of the 3D printed dosage forms in porcine stomach. In vitro dissolution testing demonstrated almost complete first-order release of PRP and DIL (93.52 % and 99.9 %, respectively) and partial release of HCTZ (65.22 %) in the 12 h timeframe. Finally, a convolution-based single-stage approach was employed in order to predict the pharmacokinetic (PK) parameters of the API's of the formulation and the resemblance of their PK behavior with previously reported data.


Asunto(s)
Antihipertensivos , Diltiazem , Humanos , Anciano , Preparaciones de Acción Retardada/química , Comprimidos/química , Liberación de Fármacos , Hidroclorotiazida , Impresión Tridimensional , Tecnología Farmacéutica/métodos
2.
Eur J Pharm Biopharm ; 197: 114212, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38342421

RESUMEN

Capsaicin (CAP) has been implicated as a gastroprotective agent in the treatment of peptic ulcers. However, its oral administration is hampered by its poor aqueous solubility and caustic effect at high administered doses. To address these limitations, we describe the development of gastric floating, sustained release electrospun films loaded with CAP. The nanofiber films were formulated using the polymers Eudragit RL/RS and sodium bicarbonate (SB) as the effervescent agent. The films were tested for their physicochemical properties, and film buoyancy and in vitro release of CAP were assessed in simulated gastric fluid. The cytocompatibility and anti-inflammatory properties of the films were evaluated in lipopolysaccharide (LPS)-stimulated Caco-2 cells. The amorphous films showed improved wettability, a short floating lag time (<1 s) and a total floating time of over 24 h accompanied by sustained CAP release for up to 24 h. CAP-loaded films demonstrated biocompatibility with Caco-2 cells and potential cytoprotective effects by attenuating inflammatory cytokine and reactive oxygen species (ROS) production in LPS-stimulated Caco-2 cells. The gastric floating electrospun films could serve as a platform for sustained and stomach-specific drug delivery applications.


Asunto(s)
Capsaicina , Lipopolisacáridos , Humanos , Preparaciones de Acción Retardada/química , Células CACO-2 , Sistemas de Liberación de Medicamentos , Solubilidad , Comprimidos
3.
Gels ; 9(12)2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-38131970

RESUMEN

In this work, a sodium alginate-based copolymer grafted by thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) chains was used as gelator (Alg-g-PNIPAM) in combination with methylcellulose (MC). It was found that the mechanical properties of the resulting gel could be enhanced by the addition of MC and calcium ions (Ca2+). The proposed network is formed via a dual crosslinking mechanism including ionic interactions among Ca2+ and carboxyl groups and secondary hydrophobic associations of PNIPAM chains. MC was found to further reinforce the dynamic moduli of the resulting gels (i.e., a storage modulus of ca. 1500 Pa at physiological body and post-printing temperature), rendering them suitable for 3D printing in biomedical applications. The polymer networks were stable and retained their printed fidelity with minimum erosion as low as 6% for up to seven days. Furthermore, adhered pre-osteoblastic cells on Alg-g-PNIPAM/MC printed scaffolds presented 80% viability compared to tissue culture polystyrene control, and more importantly, they promoted the osteogenic potential, as indicated by the increased alkaline phosphatase activity, calcium, and collagen production relative to the Alg-g-PNIPAM control scaffolds. Specifically, ALP activity and collagen secreted by cells were significantly enhanced in Alg-g-PNIPAM/MC scaffolds compared to the Alg-g-PNIPAM counterparts, demonstrating their potential in bone tissue engineering.

4.
J Pharm Sci ; 112(10): 2644-2654, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37549845

RESUMEN

Buccal foams containing omeprazole (OME) have been developed as potential drug delivery systems for individuals encountering swallowing difficulties, particularly pediatric and geriatric patients. The buccal foams were formulated from lyophilized aqueous gels of maltodextrin, used as a sweetener, combined with various polymers (alginate, chitosan, gelatin, tragacanth) to fine tune their structural, mechanical, and physicochemical properties. Consistent with the requirements for efficient drug delivery across buccal epithelium, the foam comprised of hydroxypropyl methylcellulose and alginate (HPMC-Alg-OME), exhibited moderate hardness and high mucoadhesion resulting to prolonged residence and increased transport of the active across porcine epithelium. The HPMC-Alg-OME foam induced a 30-fold increase in the drug's apparent permeability across porcine buccal tissue, compared to the drug suspension. The developed buccal foams exhibited excellent stability, as evidenced by the unchanged omeprazole content even after six months of storage under ambient conditions (20 °C and 45% RH). Results indicate that buccal foams of omeprazole may address the stability and ease of administration issues related to oral administration of the drug, particularly for children and elderly patients who have difficulty swallowing solid dosage forms.


Asunto(s)
Deglución , Omeprazol , Animales , Porcinos , Sistemas de Liberación de Medicamentos , Administración Oral , Alginatos , Administración Bucal , Mucosa Bucal
5.
Gels ; 8(11)2022 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-36354613

RESUMEN

Medium Chain Triglyceride (MCT) oil was successfully combined with Glyceryl Monostearate (GMS) and Glyceryl Monoolein (GMO) to form oleogels that were subsequently whipped to form stable oleofoams. The co-crystallization of GMS and GMO at a ratio of 20:1, 20:2.5, and 20:5 within MCT oil was studied through Differential Scanning Calorimetry (DSC), X-ray Diffraction analysis (XRD), rheological analysis, Fluorescence Recovery after Photobleaching (FRAP), Fourier Transform Infrared Spectroscopy (FTIR), and polarized microscopy. The addition of 5% GMO resulted in the production of more stable oleogels in terms of crystal structure and higher peak melting point, rendering this formulation suitable for pharmaceutical applications that are intended to be used internally and those that require stability at temperatures close to 40 °C. All formulations were whipped to form oleofoams that were evaluated for their storage stability for prolonged period at different temperatures. The results show that oleofoams containing 5% MGO retained their foam characteristics even after 3 months of storage under different temperature conditions.

6.
ACS Biomater Sci Eng ; 8(5): 2096-2110, 2022 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-35427110

RESUMEN

Treatment failure of endodontic infections and their concurrent inflammations is commonly associated with microbial persistence and reinfection, also stemming from the anatomical restrictions of the root canal system. Aiming to address the shortcomings of current treatment options, a fast-disintegrating nanofibrous film was developed for the intracanal coadministration of an antimicrobial (ZnO nanoparticles) and an anti-inflammatory (ketoprofen) agent. The electrospun films were fabricated based on polymers that dissolve rapidly to constitute the actives readily available at the site of action, aiming to eliminate both microbial infection and inflammation. The anti-inflammatory potency of the nanofiber films was assessed in an in vitro model of lipopolysaccharide (LPS)-stimulated RAW 264.7 cells after confirming their biocompatibility in the same cell line. The nanofiber films were found effective against Enterococcus faecalis, one of the most prominent pathogens inside the root canal space, both in vitro and ex vivo using a human tooth model experimentally infected with E. faecalis. The physical properties and antibacterial and anti-inflammatory potency of the proposed electrospun nanofiber films constitute a promising therapeutic module in the endodontic therapy of nonvital infected teeth. All manuscripts must be accompanied by an abstract. The abstract should briefly state the problem or purpose of the research, indicate the theoretical or experimental plan used, summarize the principal findings, and point out major conclusions.


Asunto(s)
Antiinfecciosos , Infecciones Bacterianas , Nanofibras , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Enterococcus faecalis , Humanos , Inflamación/tratamiento farmacológico , Nanofibras/uso terapéutico
7.
J Pharm Sci ; 111(9): 2562-2570, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35469835

RESUMEN

In an effort to combine a child-friendly dosage form for medication administration in hospitalized pediatric patients and a user-friendly automated process for its preparation by health-care providers, the current study proposes a method for drug administration with breakfast using semi-solid extrusion 3D printing. Cereal was used as the platform carrier of the hydrophobic ibuprofen and the hydrophilic paracetamol to develop the drug loaded cereal ink. Rheological analysis was performed to identify the cereal ink with optimum viscosity for extrusion printing. Drug distribution and crystallinity within the printed cereal were assessed with confocal Raman microscopy and thermal and X-ray diffraction analysis, respectively, indicating molecular dispersion of both drugs within the cereal. High cereal porosity was associated with a higher milk absorption capacity and a decrease in their flexural force upon immersion in milk. Dissolution studies were performed in biorelevant media under fasted and fed state conditions and in the presence of full-fat and low-fat milk showing dissolution enhancement of the poorly soluble ibuprofen in the presence of the higher fat content milk. Concealing drug administration under the auspice of this essential daily eating habit is expected to facilitate overcoming adherence barriers to medication intake by pediatric patients within a hospital setting.


Asunto(s)
Grano Comestible , Ibuprofeno , Desayuno , Niño , Formas de Dosificación , Liberación de Fármacos , Hospitales , Humanos , Preparaciones Farmacéuticas , Impresión Tridimensional
8.
Artículo en Inglés | MEDLINE | ID: mdl-35405570

RESUMEN

Controlled-release tablets and rectal suppositories of sulfasalazine (SLF) and hydrocortisone 21-acetate (HA) were prepared as recommended dosage forms for the treatment of acute episodes of ulcerative colitis, in patients who do not respond to monotherapy. A High-Performance Liquid Chromatography (HPLC) Diode-array method with a gradient elution mobile phase was developed to evaluate the production quality of both formulations (assay and dissolution profiles in gastric and intestinal fluids). Method's validation was carried out providing good linearity (r ≥ 0.9995), precision (RSD < 1.53%), recovery (96.9% - 103.7%) and limits of detection (LODSLF = 12 ng/mL, LODHA = 15 ng/mL). Experimental design and Plackett-Burman methodology was constructed to study the robustness of the analysis. In all composite substrates, a freezing lipid precipitation approach was used as purification step. The method was optimized by applying Central Composite design mode. The in-vitro/ex-vivo permeability studies of both formulations were evaluated by a Liquid Chromatography-Electron Spray Ionization Mass Spectrometry (LC-ESI/MS) +/- mode. The analysis of sulfamethazine (internal standard, SLM, m/z 279), HA (m/z 449, [M + HCOO]-), SLF (m/z 399) and its active metabolite mesalazine (MSL, m/z 154) was performed using a C18 column and gradient elution. The validation of the method met the requirements of the International Council for Harmonization (ICH) (r ≥ 0.9997, RSD ≤ 4.62%, Recovery > 95%, LODSLF = 1.28 ng/mL, LODHA = 1.07 ng/mL, LODMSL = 3.16 ng/mL). Based on the results, important conclusions were drawn concerning the role of excipients and SLF metabolism.


Asunto(s)
Mesalamina , Sulfasalazina , Cromatografía Líquida de Alta Presión/métodos , Humanos , Hidrocortisona/análogos & derivados , Permeabilidad , Reproducibilidad de los Resultados , Supositorios , Comprimidos
9.
Biomater Adv ; 133: 112723, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35474147

RESUMEN

Periodontal disease is associated with chronic inflammation and destruction of the soft and hard tissues in the periodontium. Scaffolds that would enable cell attachment and proliferation while at the same time providing a local sustained anti-inflammatory action would be beneficial in restoring or reversing disease progression. In the current study, silk sericin, a natural protein derived from the silkworm cocoons, was electrospun with poly lactide-co-glycolic acid (PLGA) and ketoprofen, and the composite scaffolds were assessed for their physicochemical and mechanical properties, as well as their biocompatibility and in vitro anti-inflammatory action. The composite scaffolds showed an increase in their hydrophilicity and an exceptional reinforcement of their mechanical properties, compared to plain PLGA scaffolds, sustaining drug release for up to 15 days. Human gingival fibroblasts showed a favorable attachment and proliferation on the composite scaffolds as visualized with scanning electron and confocal microscopy. A significant downregulation of the pro-inflammatory markers MMP-9 and MMP-3 and an upregulation of the anti-inflammatory gene IL-10 was achieved for lipopolysaccharide-stimulated RAW 264.7 macrophages after cultivation on the composite scaffolds. The current study demonstrated that silk sericin-PLGA composite scaffolds have the potential to simultaneously accommodate cell attachment and proliferation and achieve a sustained anti-inflammatory action in the treatment of periodontal diseases.


Asunto(s)
Sericinas , Ingeniería de Tejidos , Animales , Antiinflamatorios/farmacología , Glicolatos , Humanos , Ácido Láctico/química , Ratones , Periodoncio , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Células RAW 264.7 , Sericinas/farmacología , Andamios del Tejido/química
10.
Pharmaceutics ; 14(1)2022 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-35057029

RESUMEN

Fibrillar structures derived from plant or animal origin have long been a source of inspiration for the design of new biomaterials. The Asn-Gly-Ile-Trp-Tyr-NH2 (NGIWY-amide) pentapeptide, isolated from the sea cucumber Apostichopus japonicus, which spontaneously self-assembles in water to form hydrogel, pertains to this category. In this study, we evaluated this ultra-short cosmetic bioinspired peptide as vector for local drug delivery applications. Combining nuclear magnetic resonance, circular dichroism, infrared spectroscopy, X-ray diffraction, and rheological studies, the synthesized pentapeptide formed a stiff hydrogel with a high ß-sheet content. Molecular dynamic simulations aligned well with scanning electron and atomic-force microscopy studies, revealing a highly filamentous structure with the fibers adopting a helical-twisted morphology. Model dye localization within the supramolecular hydrogel provided insights on the preferential distribution of hydrophobic and hydrophilic compounds in the hydrogel network. That was further depicted in the diffusion kinetics of drugs differing in their aqueous solubility and molecular weight, namely, doxorubicin hydrochloride, curcumin, and octreotide acetate, highlighting its versatility as a delivery vector of both hydrophobic and hydrophilic compounds of different molecular weight. Along with the observed cytocompatibility of the hydrogel, the NGIWY-amide pentapeptide may offer new approaches for cell growth, drug delivery, and 3D bioprinting tissue-engineering applications.

11.
J Pharm Pharmacol ; 74(10): 1498-1506, 2022 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-34468746

RESUMEN

OBJECTIVES: The development of age-appropriate dosage forms is essential for effective pharmacotherapy, especially when long-term drug treatment is required, as in the case of latent tuberculosis infection treatment with up to 9 months of daily isoniazid (ISO). Herein, we describe the fabrication of starch-based soft dosage forms of ISO using semi-solid extrusion (SSE) 3D printing. METHODS: Corn starch was used for ink preparation using ISO as model drug. The inks were characterized physicochemically and their viscoelastic properties were assessed with rheological analysis. The morphology of the printed dosage forms was visualized with scanning electron microscopy and their textural properties were evaluated using texture analysis. Dose accuracy was verified before in-vitro swelling and dissolution studies in simulated gastric fluid (SGF). KEY FINDINGS: Starch inks were printed with good resolution and high drug dose accuracy. The printed dosage forms had a soft texture to ease administration in paediatric patients and a highly porous microstructure facilitating water penetration and ISO diffusion in SGF, resulting in almost total drug release within 45 min. CONCLUSIONS: The ease of preparation and fabrication combined with the cost-effectiveness of the starting materials constitutes SSE 3D printing of starch-based soft dosage forms a viable approach for paediatric-friendly formulations in low-resource settings.


Asunto(s)
Isoniazida , Tuberculosis Latente , Niño , Formas de Dosificación , Liberación de Fármacos , Excipientes/química , Humanos , Lactante , Impresión Tridimensional , Almidón , Comprimidos/química , Tecnología Farmacéutica/métodos , Agua
12.
Mol Pharm ; 19(1): 274-286, 2022 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-34877863

RESUMEN

Most common intraocular pressure (IOP) reduction regimens for the management of glaucoma include the topical use of eye drops, a dosage form that is associated with short residence time at the site of action, increased dosing frequency, and reduced patient compliance. In situ gelling nanofiber films comprising poly(vinyl alcohol) and Poloxamer 407 were fabricated via electrospinning for the ocular delivery of timolol maleate (TM), aiming to sustain the IOP-lowering effect of the ß-blocker, compared to conventional eye drops. The electrospinning process was optimized, and the physicochemical properties of the developed formulations were thoroughly investigated. The fiber diameters of the drug-loaded films ranged between 123 and 145 nm and the drug content between 5.85 and 7.83% w/w. Total in vitro drug release from the ocular films was attained within 15 min following first-order kinetics, showing higher apparent permeability (Papp) values across porcine corneas compared to the drug's solution. The fabricated films did not induce any ocular irritation as evidenced by both the hen's egg test on chorioallantoic membrane and the in vivo Draize test. In vivo administration of the ocular films in rabbits induced a faster onset of action and a sustained IOP-lowering effect up to 24 h compared to TM solution, suggesting that the proposed ocular films are promising systems for the sustained topical delivery of TM.


Asunto(s)
Antagonistas Adrenérgicos beta/farmacología , Geles , Presión Intraocular/efectos de los fármacos , Timolol/farmacología , Administración Oftálmica , Antagonistas Adrenérgicos beta/administración & dosificación , Animales , Cromatografía Líquida de Alta Presión , Córnea/efectos de los fármacos , Córnea/metabolismo , Geles/administración & dosificación , Poloxámero , Alcohol Polivinílico , Porcinos , Timolol/administración & dosificación
13.
Eur J Pharm Sci ; 165: 105955, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34298141

RESUMEN

In the present study, a multi-component system comprised of dipalmitylphospatidylcholine (DPPC), Chitosan, Lactose, and L-Leucine was developed for pulmonary delivery. Microparticles were engineered by the spray drying process and the selection of the critical parameters was performed by applying experimental design. The microcarriers with the appropriate size and yield were co-formulated with two active pharmaceutical ingredients (APIs), namely, Formoterol fumarate and Budesonide, and they were further investigated. All formulations exhibited spherical shape, appropriate aerodynamic performance, satisfying entrapment efficiency, and drug load. Their physicochemical properties were evaluated using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), and Differential Scanning Calorimetry (DSC). The aerodynamic particle size characterization was determined using an eight-stage Andersen cascade impactor, whereas the release of the actives was monitored in vitro in simulated lung fluid. Additional evaluation of the microparticles' mucoadhesive properties was performed by ζ-potential measurements and ex vivo mucoadhesion study applying a falling liquid film method using porcine lung tissue. Cytotoxicity and cellular uptake studies in Calu-3 lung epithelial cell line were conducted to further investigate the safety and efficacy of the developed formulations.


Asunto(s)
Budesonida , Administración por Inhalación , Animales , Rastreo Diferencial de Calorimetría , Composición de Medicamentos , Fumarato de Formoterol , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Espectroscopía Infrarroja por Transformada de Fourier , Porcinos
14.
Int J Mol Sci ; 22(4)2021 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-33672949

RESUMEN

Two different types of ordered mesoporous nanoparticles, namely MCM-41 and MCM-48, with similar pore sizes but different pore connectivity, were loaded with aprepitant via a passive diffusion method. The percentage of the loaded active agent, along with the encapsulation efficiency, was evaluated using High-performance Liquid Chromatography (HPLC) analysis complemented by Thermogravimetric Analysis (TGA). The determination of the pore properties of the mesoporous particles before and after the drug loading revealed the presence of confined aprepitant in the pore structure of the particles, while Powder X-ray Diffractometry(pXRD), Differential Scanning Calorimetry (DSC), and FTIR experiments indicated that the drug is in an amorphous state. The release profiles of the drug from the two different mesoporous materials were studied in various release media and revealed an aprepitant release up to 45% when sink conditions are applied. The cytocompatibility of the silica nanoparticles was assessed in Caco-2 cell monolayers, in the presence and absence of the active agent, suggesting that they can be used as carriers of aprepitant without presenting any toxicity in vitro.


Asunto(s)
Aprepitant/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Nanopartículas/química , Dióxido de Silicio/química , Administración Oral , Antieméticos/administración & dosificación , Antieméticos/farmacocinética , Aprepitant/farmacocinética , Células CACO-2 , Rastreo Diferencial de Calorimetría , Cromatografía Líquida de Alta Presión , Difusión , Liberación de Fármacos , Humanos , Microscopía Electrónica de Rastreo , Nanopartículas/ultraestructura , Tamaño de la Partícula , Porosidad , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier
15.
Int J Pharm ; 599: 120437, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33662466

RESUMEN

Customization of pharmaceutical products is a central requirement for personalized medicines. However, the existing processing and supply chain solutions do not support such manufacturing-on-demand approaches. In order to solve this challenge, three-dimensional (3D) printing has been applied for customization of not only the dose and release characteristics, but also appearance of the product (e.g., size and shape). A solution for customization can be realized via non-expert-guided processing of digital designs and drug dose. This study presents a proof-of-concept computational algorithm which calculates the optimal dimensions of grid-like orodispersible films (ODFs), considering the recommended dose. Further, the algorithm exports a digital design file which contains the required ODF configuration. Cannabidiol (CBD) was incorporated in the ODFs, considering the simple correspondence between the recommended dose and the patient's weight. The ODFs were 3D-printed and characterized for their physicochemical, mechanical, disintegration and drug release properties. The algorithm was evaluated for its accuracy on dose estimation, highlighting the reproducibility of individualized ODFs. The in vitro performance was principally affected by the thickness and volume of the grid-like structures. The concept provides an alternative approach that promotes automation in the manufacturing of personalized medications in distributed points of care, such as hospitals and local pharmacies.


Asunto(s)
Sistemas de Liberación de Medicamentos , Impresión Tridimensional , Liberación de Fármacos , Humanos , Reproducibilidad de los Resultados
16.
AAPS PharmSciTech ; 22(1): 23, 2021 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-33400042

RESUMEN

Cannabidiol (CBD) and cannabigerol (CBG) are two active pharmaceutical ingredients, derived from cannabis plant. In the present study, CBD and CBG were formulated with polyvinyl(pyrrolidone) (PVP) and Eudragit L-100, using electrohydrodynamic atomization (electrospinning). The produced fibers were smooth and uniform in shape, with average fiber diameters in the range of 700-900 nm for PVP fibers and 1-5 µm for Eudragit L-100 fibers. The encapsulation efficiency for both CB and CBG was high (over 90%) for all formulations tested. Both in vitro release and disintegration tests of the formulations in simulated gastric fluids (SGF) and simulated intestinal fluids (SIF) indicated the rapid disintegration and dissolution of the fibers and the subsequent rapid release of the drugs. The study concluded that the electrospinning process is a fast and efficient method to produce drug-loaded fibers suitable for the per os administration of cannabinoids.


Asunto(s)
Cannabidiol/administración & dosificación , Cannabinoides/administración & dosificación , Nanofibras/química , Administración Oral , Cannabidiol/química , Cannabinoides/química , Composición de Medicamentos , Liberación de Fármacos , Ácidos Polimetacrílicos/química , Povidona/química
17.
Nanomaterials (Basel) ; 10(12)2020 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-33260313

RESUMEN

Thin Titanium films were fabricated on quartz substrates by radio frequency magnetron sputtering under high vacuum. Subsequent annealing at temperatures of 600 ∘C in air resulted in single-phase TiO2 with the structure of rutile, as X-ray diffraction experiment demonstrates. Atomic-force microscopy images verify the high crystalline quality and allow us to determine the grain size even for ultrathin TiO2 films. Rutile has a direct energy band gap at about 3.0-3.2 eV; however, the transitions between the valence and conduction band are dipole forbidden. Just a few meV above that, there is an indirect band gap. The first intense absorption peak appears at about 4 eV. Tauc plots for the position of the indirect band gap show a "blue shift" with decreasing film thickness. Moreover, we find a similar shift for the position of the first absorbance peak studied by the derivative method. The results indicate the presence of quantum confinement effects. This conclusion is supported by theoretical calculations based on a combination of the effective mass theory and the Hartree Fock approximation.

18.
Elife ; 92020 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-33295868

RESUMEN

Protein phosphorylation, critical for cellular regulatory mechanisms, is implicated in various diseases. However, it remains unknown whether heterogeneity in phosphorylation of key structural proteins alters tissue integrity and organ function. Here, osteopontin phosphorylation level declined in hypo- and hyper- phosphatemia mouse models exhibiting skeletal deformities. Phosphorylation increased cohesion between osteopontin polymers, and adhesion of osteopontin to hydroxyapatite, enhancing energy dissipation. Fracture toughness, a measure of bone's mechanical competence, increased with ex-vivo phosphorylation of wildtype mouse bones and declined with ex-vivo dephosphorylation. In osteopontin-deficient mice, global matrix phosphorylation level was not associated with toughness. Our findings suggest that phosphorylated osteopontin promotes fracture toughness in a dose-dependent manner through increased interfacial bond formation. In the absence of osteopontin, phosphorylation increases electrostatic repulsion, and likely protein alignment and interfilament distance leading to decreased fracture resistance. These mechanisms may be of importance in other connective tissues, and the key to unraveling cell-matrix interactions in diseases.


Asunto(s)
Huesos/fisiopatología , Matriz Extracelular/fisiología , Fracturas Óseas/fisiopatología , Osteopontina/metabolismo , Animales , Fracturas Óseas/metabolismo , Ratones , Fosforilación , Estrés Mecánico
19.
Langmuir ; 36(44): 13292-13300, 2020 11 10.
Artículo en Inglés | MEDLINE | ID: mdl-33118809

RESUMEN

Achieving strong adhesion in wet environments remains a technological challenge in biomedical applications demanding biocompatibility. Attention for adhesive motifs meeting such demands has largely been focused on marine organisms. However, bioadhesion to inorganic surfaces is also present in the human body, in the hard tissues of teeth and bones, and is mediated through serines (S). The specific amino acid sequence DpSpSEEKC has been previously suggested to be responsible for the strong binding abilities of the protein statherin to hydroxyapatite, where pS denotes phosphorylated serine. Notably, similar sequences are present in the non-collagenous bone protein osteopontin (OPN) and the mussel foot protein 5 (Mefp5). OPN has previously been shown to promote fracture toughness and physiological damage formation. Here, we investigated the adhesion strength of the motif D(pS)(pS)EEKC on substrates of hydroxyapatite, TiO2, and mica using atomic force microscopy (AFM) single-molecule force spectroscopy (SMFS). Specifically, we investigated the dependence of adhesion force on phosphorylation of serines by comparing findings with the unphosphorylated variant DSSEEKC. Our results show that high adhesion forces of over 1 nN on hydroxyapatite and on TiO2 are only present for the phosphorylated variant D(pS)(pS)EEKC. This warrants further exploitation of this motif or similar residues in technological applications. Further, the dependence of adhesion force on phosphorylation suggests that biological systems potentially employ an adhesion-by-demand mechanism via expression of enzymes that up- or down-regulate phosphorylation, to increase or decrease adhesion forces, respectively.

20.
Pharmaceuticals (Basel) ; 13(9)2020 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-32825421

RESUMEN

Buccal films containing two vitamins, i.e., thiamine hydrochloride (THCl) and nicotinic acid (NA), were fabricated via two-dimensional (2D) inkjet printing. For the preparation of buccal films, solubility studies and rheological evaluations were conducted in distilled water and propylene-glycol (PG) as main solvent and viscosity/surface tension modifier, respectively. The increased solubility in the solvents' mixture indicated that manufacturing of several doses of the THCl and NA is achievable. Various doses were deposited onto sugar-sheet substrates, by increasing the number of printing passes. The physiochemical characterization (SEM, DSC, FTIR) revealed that inkjet printing does not affect the solid state of the matrix. Water uptake studies were conducted, to compare the different vitamin-loaded formulations. The in vitro release studies indicated the burst release of both vitamins within 10 min, a preferable feature for buccal administration. The in vitro permeation studies indicated that higher concentrations of the vitamins onto the sugar sheet improved the in vitro permeation performance of printed formulations.

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