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1.
Saudi Pharm J ; 32(4): 102002, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38439951

RESUMEN

Pectin hydrogels have emerged as a highly promising medium for the controlled release of pharmaceuticals in the dynamic field of drug delivery. The present review sheds light on the broad range of applications and potential of pectin-based hydrogels in pharmaceutical formulations. Pectin, as a biopolymer, is a versatile candidate for various drug delivery systems because of its wide range of properties and characteristics. The information provided on formulation strategies and crosslinking techniques provides researchers with tools to improve drug entrapment and controlled release. Furthermore, this review provides a more in-depth understanding of the complex factors influencing drug release from pectin hydrogels, such as the impact of environmental conditions and drug-specific characteristics. Pectin hydrogels demonstrate adaptability across diverse domains, ranging from applications in oral and transdermal drug delivery to contributions in wound healing, tissue engineering, and ongoing clinical trials. While standardization and regulatory compliance remain significant challenges, the future of pectin hydrogels appears to be bright, opening up new possibilities for advanced drug delivery systems.

2.
J Microencapsul ; 39(1): 61-71, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34984941

RESUMEN

This study aimed to encapsulate and characterise a potential anti-tuberculosis copper complex (CuCl2(INH)2.H2O:I1) into polymeric nanoparticles (PNs) of polymethacrylate copolymers (Eudragit®, Eu) developed by nanoprecipitation method. NE30D, S100 and, E100 polymers were tested. The physicochemical characterisations were performed by DLS, TEM, FTIR, encapsulation efficiency and, in vitro release studies. Encapsulation of I1 in PN-NE30D, PN-E100, and PN-S100 was 26.3%, 94.5%, 22.6%, respectively. The particle size and zeta potentials were 82.3 nm and -24.5 mV for PNs-NE30D, 304.4 nm and +18.7 mV for PNs-E100, and 517.9 nm and -6.9 mV for PNs-S100, respectively. All PDIs were under 0.5. The formulations showed an I1 controlled release at alkaline pH with 29.7% from PNs-NE30D, 7.9% from PNs-E100 and, 28.1% from PNs-S100 at 1 h incubation. PNs were stable for at least 3 months. Particularly, PNs-NE30D demonstrated moderate inhibition of M. tuberculosis and low cytotoxic activity. None of the PNs induced mutagenicity.


Asunto(s)
Cobre , Nanopartículas , Antibacterianos , Cobre/farmacología , Mutágenos , Tamaño de la Partícula , Polímeros
3.
World J Microbiol Biotechnol ; 37(9): 151, 2021 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-34398340

RESUMEN

The aim of the current review is to address updated research on a natural pigment called violacein, with emphasis on its production, biological activity and applications. New information about violacein's action mechanisms as antitumor agent and about its synergistic action in drug delivery systems has brought new alternatives for anticancer therapy. Thus, violacein is introduced as reliable drug capable of overcoming at least three cancer hallmarks, namely: proliferative signaling, cell death resistance and metastasis. In addition, antimicrobial effects on several microorganisms affecting humans and other animals turn violacein into an attractive drug to combat resistant pathogens. Emphasis is given to effects of violacein combined with different agents, such as antibiotics, anticancer agents and nanoparticles. Although violacein is well-known for many decades, it remains an attractive compound. Thus, research groups have been making continuous effort to help improving its production in recent years, which can surely enable its pharmaceutical and chemical application as multi-task compound, even in the cosmetics and food industries.


Asunto(s)
Antiinfecciosos/farmacología , Antineoplásicos/farmacología , Indoles/farmacología , Animales , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Cosméticos , Farmacorresistencia Microbiana/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Industria de Alimentos , Humanos
4.
Environ Res ; 189: 109857, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32777636

RESUMEN

The toxic effects of silver nanoparticles (AgNPs) on the physiology and morphology of the green microalga Chlorella vulgaris were studied. AgNPs were characterized by particle size distribution, ζ potential measurement, and atomic force microscopy (AFM). Chlorella vulgaris was exposed to 90-1440 µg/L of AgNPs range in Bold's Basal Medium for 96 h. The inhibition of algae growth rate and changes in the concentrations of chlorophyll-a, chlorophyll-b, pheophytin, and carotenoids was determined at the beginning and end of the trial. Cell diameter and volume, carbohydrate, total lipids, and protein content were also determined. Our data strongly suggest that the toxic effects of the AgNPs resulted in concentration and time-dependent. AgNPs altered C. vulgaris growth kinetics and cell metabolism expressed in photosynthetic pigments and biochemical composition. Our study confirmed the cytotoxicity of AgNPs through the algal growth inhibition with an EC50 value of 110 µg/L. Also, changes of chlorophyll-a, chlorophyll-b, pheophytin, and carotenoids concentrations were observed associated with a color shift from green to pale brown of algae cultures exposed to AgNPs for 96 h. Furthermore, algae cell concentration, diameter, and volume, plus total lipid, protein, and carbohydrates contents in the presence of AgNPs, were significantly altered compared to untreated cells. In synthesis, this study highlighted AgNPs toxic effects on morphological and physiological traits of C. vulgaris and warns about possible impacts on energy flow and aquatic food web structure, and on the transfer efficiency of energy to higher trophic levels.


Asunto(s)
Chlorella vulgaris , Nanopartículas del Metal , Microalgas , Clorofila A , Nanopartículas del Metal/toxicidad , Plata/toxicidad
5.
Sensors (Basel) ; 20(18)2020 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-32957656

RESUMEN

This work presents a non-invasive and low-cost alternative to traditional methods for measuring the performance of machining processes directly on existing machine tools. A prototype measuring system has been developed based on non-contact microphones, a custom designed signal conditioning board and signal processing techniques that take advantage of the underlying physics of the machining process. Experiments have been conducted to estimate the depth of cut during end-milling process by means of the measurement of the acoustic emission energy generated during operation. Moreover, the predicted values have been compared with well established methods based on cutting forces measured by dynamometers.

6.
Molecules ; 26(1)2020 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-33374301

RESUMEN

Bacterial cellulose (BC) is a natural polymer that has fascinating attributes, such as biocompatibility, low cost, and ease of processing, being considered a very interesting biomaterial due to its options for moldability and combination. Thus, BC-based compounds (for example, BC/collagen, BC/gelatin, BC/fibroin, BC/chitosan, etc.) have improved properties and/or functionality, allowing for various biomedical applications, such as artificial blood vessels and microvessels, artificial skin, and wounds dressing among others. Despite the wide applicability in biomedicine and tissue engineering, there is a lack of updated scientific reports on applications related to dentistry, since BC has great potential for this. It has been used mainly in the regeneration of periodontal tissue, surgical dressings, intraoral wounds, and also in the regeneration of pulp tissue. This review describes the properties and advantages of some BC studies focused on dental and oral applications, including the design of implants, scaffolds, and wound-dressing materials, as well as carriers for drug delivery in dentistry. Aligned to the current trends and biotechnology evolutions, BC-based nanocomposites offer a great field to be explored and other novel features can be expected in relation to oral and bone tissue repair in the near future.


Asunto(s)
Bacterias/química , Materiales Biocompatibles/química , Celulosa/química , Odontología , Celulosa/ultraestructura , Odontología/métodos , Polisacáridos Bacterianos/química , Polisacáridos Bacterianos/ultraestructura
7.
Anal Biochem ; 555: 59-66, 2018 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-29908862

RESUMEN

The development of simple, fast and reproducible techniques that provide information about the antioxidant activity (AA) of different compounds is essential to screen and discover new molecules with potential applications in the therapeutic, cosmetic, toxicological and food fields. Here, a novel and simple colorimetric method ("BCB assay") is proposed for measuring the AA of chemical compounds by protection of the reporter dye Brilliant Cresyl Blue (BCB) from loss of color due to oxidation by hypochlorite (a physiological oxidant). The decay in BCB blue color (λmax = 634 nm) in the presence of hypochlorite occurred in only 5 min and was used to track the AA of different molecules. Particularly, the AA of monoterpenes was demonstrated and used to quantify them at milimolar concentrations. Natural antioxidants like vitamins C and E, resveratrol, dithiothreitol, N-actyl-l-cysteine and glutathione were used as controls to validate the assay. Linalool, geraniol and 1,8-cineole were tested and showed in vitro AA in a concentration-dependent manner. The monoterpene concentrations providing 50% protection against oxidation (AA50) were 2.3, 36.2 and 135.0 mM for linalool, geraniol and 1,8-cineole respectively, suggesting interesting AA. The method provides a useful, fast, simple and low-cost tool to determine the in vitro AA of different molecules.


Asunto(s)
Antioxidantes/análisis , Monoterpenos/análisis , Oxazinas/química , Colorimetría/métodos , Oxidación-Reducción
8.
Crit Rev Biotechnol ; 36(3): 447-64, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-25641329

RESUMEN

Therapeutic enzymes are one of the most promising applications of this century in the field of pharmaceutics. Biocatalyst properties can be improved by enzyme immobilization on nano-objects, thereby increasing stability and reusability and also enhancing the targeting to specific tissues and cells. Therapeutic biocatalyst-nanodevice complexes will provide new tools for the diagnosis and treatment of old and newly emerging pathologies. Among the advantages of this approach are the wide span and diverse range of possible materials and biocatalysts that promise to make the matrix-enzyme combination a unique modality for therapeutic delivery. This review focuses on the most significant techniques and nanomaterials used for enzyme immobilization such as metallic superparamagnetic, silica, and polymeric and single-enzyme nanoparticles. Finally, a review of the application of these nanodevices to different pathologies and modes of administration is presented. In short, since therapeutic enzymes constitute a highly promising alternative for treating a variety of pathologies more effectively, this review is aimed at providing the comprehensive summary needed to understand and improve this burgeoning area.


Asunto(s)
Sistemas de Liberación de Medicamentos , Enzimas Inmovilizadas , Nanomedicina
9.
Neuromodulation ; 19(4): 357-64, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27075563

RESUMEN

BACKGROUND: Prelemniscal radiations (Raprl) have been proposed as a target for the treatment of Parkinson's disease. We evaluated effectiveness of this target through UPDRS-III in patients treated with Raprl deep brain stimulation (Raprl-DBS) and followed from 24 to 48 months. METHODS: Nineteen patients in Hoehn-Yahr stages II-III were implanted with tetrapolar deep brain stimulation electrodes in Raprl contralateral to the extremities with more prominent symptoms. Placement was assisted by MRI/CT/anatomical atlas fusion, microelectrode recording, and micro- and macro-stimulation. The effect on motor symptoms was evaluated in an open label protocol through specific items of the UPDRS-III score, applied pre-operatively and 6, 12, 24, and 48 months after the onset of stimulation in an OFF-medication/ON-stimulation condition. Changes in scores with regard to pre-operative condition were obtained for each symptom in both sides and statistical significance determined through double-tail Wilcoxon test. Influence of demographic variables on outcome was analyzed using linear regression testing. RESULTS: A greater than 80% decrease in UPDRS score for contralateral symptoms (classified as excellent results) occurred in 14 patients (73.7%), while in the other 5 it decreased from 33 to 79% (considered suboptimal results). These changes remained statistically significant up to 48 months (p < 0.01), while ipsilateral symptoms progressively increased. Suboptimal results were associated with selective improvement of only one symptom. CONCLUSION: Raprl-DBS induces a long-term, significant improvement of contralateral acral symptoms of Parkinson's disease.


Asunto(s)
Estimulación Encefálica Profunda/métodos , Lateralidad Funcional/fisiología , Enfermedad de Parkinson/terapia , Resultado del Tratamiento , Adulto , Anciano , Antiparkinsonianos/uso terapéutico , Electrodos Implantados , Femenino , Humanos , Levodopa/uso terapéutico , Estudios Longitudinales , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Enfermedad de Parkinson/diagnóstico por imagen , Núcleo Subtalámico/fisiología
10.
Stereotact Funct Neurosurg ; 93(4): 282-91, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26183393

RESUMEN

OBJECTIVE: To better define prelemniscal radiations (Raprl) as a target for the control of tremor and rigidity in Parkinson's disease (PD). METHODS: A total of 36 deep brain stimulation (DBS) electrodes were stereotactically implanted in Raprl contralateral to the extremities to be treated. Effects on symptoms were evaluated using UPDRS-III before and after DBS, and significance was determined using the Wilcoxon test. The location of DBS contacts in cases with optimum versus suboptimum results was evaluated using Student's t test and percentage improvement correlated through a bivariable Pearson test. The power and percentage of spike components for microelectrode recordings were statistically compared between the target point and structures located above and below. RESULTS: Raprl-DBS improved tremor and rigidity (p < 0.01). The potency of microelectrode recordings indicated that the target was formed by fibers. There was no correlation between demographic characteristics and clinical outcome, and there were no significant differences in stereotactic placement between cases with optimum and suboptimum results. Tremor and rigidity were selectively improved in cases with suboptimum results. CONCLUSION: Raprl-DBS is an effective treatment for the motor symptoms of PD. Selective improvement of symptoms suggests that the target has different fiber components related to either tremor or rigidity, and variations in improvement between cases may derive from individual variations of the location of these fibers.


Asunto(s)
Estimulación Encefálica Profunda/métodos , Rigidez Muscular/terapia , Enfermedad de Parkinson/terapia , Subtálamo/fisiopatología , Temblor/terapia , Adulto , Anciano , Electrodos Implantados , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Microelectrodos , Persona de Mediana Edad , Rigidez Muscular/etiología , Rigidez Muscular/fisiopatología , Fibras Nerviosas/fisiología , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/fisiopatología , Técnicas Estereotáxicas , Subtálamo/patología , Resultado del Tratamiento , Temblor/etiología , Temblor/fisiopatología , Sustancia Blanca/patología , Sustancia Blanca/fisiopatología
12.
Carbohydr Polym ; 339: 122266, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-38823930

RESUMEN

Konjac glucomannan (KG) is a dietary fiber hydrocolloid derived from Amorphophallus konjac tubers and is widely utilized as a food additive and dietary supplement. As a health-conscious choice, purified KG, along with konjac flour and KG-infused diets, have gained widespread acceptance in Asian and European markets. An overview of the chemical composition and structure of KG is given in this review, along with thorough explanations of the processes used in its extraction, production, and purification. KG has been shown to promote health by reducing glucose, cholesterol, triglyceride levels, and blood pressure, thereby offering significant weight loss advantages. Furthermore, this review delves into the extensive health benefits and pharmaceutical applications of KG and its derivatives, emphasizing its prebiotic, anti-inflammatory, and antitumor activities. This study highlights how these natural polysaccharides can positively influence health, underscoring their potential in various biomedical applications.


Asunto(s)
Amorphophallus , Mananos , Mananos/química , Mananos/aislamiento & purificación , Humanos , Amorphophallus/química , Animales , Fibras de la Dieta/análisis , Antiinflamatorios/química , Antiinflamatorios/farmacología , Antiinflamatorios/aislamiento & purificación , Suplementos Dietéticos , Prebióticos , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Antineoplásicos/farmacología
13.
World Neurosurg ; 189: e999-e1005, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39004176

RESUMEN

BACKGROUND: Glioblastomas are among the most malignant tumors which, despite aggressive treatment, currently have an abysmal prognosis. These lesions are known to cause local and systemic perturbations in the coagulation system, leading to neoangiogenesis and a high risk of venous thromboembolism. Indeed, there have been multiple proposals of the coagulation system being a possible target for future treatment of these patients. However, nonselective anticoagulant therapy has proven suboptimal and leads to a significant increase of intracranial hemorrhage. Thus, recognizing factors that lead to hypercoagulation is considered paramount. Hyperglycemia is a well-known prothrombotic factor, a fact that has received little attention in neuro-oncology. We previously hypothesized that patients with brain tumors could be highly susceptible to iatrogenic glycemia dysregulation. Here, we analyzed the connection between glycated hemoglobin (HbA1c) and the routine coagulation markers (D-dimers, prothrombin time and activated partial thromboplastin time [aPTT]) in patients with de novo intracranial glioblastomas. METHODS: Included in this study were 74 patients who were operated on in 2 hospitals: Clinical Hospital Dubrava, Zagreb, Croatia; University Hospital Center Split, Split, Croatia; and University Hospital de la Princesa, Madrid, Spain. RESULTS: We found a significant inverse correlation between HbA1c and aPTT (ρ = -0.379; P = 0.0009). We also found a significant inverse correlation between Ki67 immunoreactivity and aPTT (ρ = -0.211; P = 0.0082). No connection was found between HbA1c and D-dimers or prothrombin time. CONCLUSIONS: Our results suggest that patients with hyperglycemia, with a more proliferative glioblastoma, could in fact have their coagulation profile significantly disrupted, primarily through the intrinsic coagulation pathway. Such findings could have great clinical importance. Further research in this area could help to elucidate the vicious connection between glioblastomas and coagulation and to combat this deadly disease.


Asunto(s)
Coagulación Sanguínea , Neoplasias Encefálicas , Glioblastoma , Hemoglobina Glucada , Humanos , Glioblastoma/sangre , Glioblastoma/complicaciones , Neoplasias Encefálicas/sangre , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/cirugía , Femenino , Persona de Mediana Edad , Masculino , Anciano , Hemoglobina Glucada/análisis , Hemoglobina Glucada/metabolismo , Coagulación Sanguínea/fisiología , Hiperglucemia/sangre , Glucemia/análisis , Glucemia/metabolismo , Adulto , Tiempo de Tromboplastina Parcial , Productos de Degradación de Fibrina-Fibrinógeno/metabolismo , Productos de Degradación de Fibrina-Fibrinógeno/análisis , Tiempo de Protrombina
14.
Open Res Eur ; 4: 140, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39139813

RESUMEN

Observations at (sub-)millimeter wavelengths offer a complementary perspective on our Sun and other stars, offering significant insights into both the thermal and magnetic composition of their chromospheres. Despite the fundamental progress in (sub-)millimeter observations of the Sun, some important aspects require diagnostic capabilities that are not offered by existing observatories. In particular, simultaneously observations of the radiation continuum across an extended frequency range would facilitate the mapping of different layers and thus ultimately the 3D structure of the solar atmosphere. Mapping large regions on the Sun or even the whole solar disk at a very high temporal cadence would be crucial for systematically detecting and following the temporal evolution of flares, while synoptic observations, i.e., daily maps, over periods of years would provide an unprecedented view of the solar activity cycle in this wavelength regime. As our Sun is a fundamental reference for studying the atmospheres of active main sequence stars, observing the Sun and other stars with the same instrument would unlock the enormous diagnostic potential for understanding stellar activity and its impact on exoplanets. The Atacama Large Aperture Submillimeter Telescope (AtLAST), a single-dish telescope with 50m aperture proposed to be built in the Atacama desert in Chile, would be able to provide these observational capabilities. Equipped with a large number of detector elements for probing the radiation continuum across a wide frequency range, AtLAST would address a wide range of scientific topics including the thermal structure and heating of the solar chromosphere, flares and prominences, and the solar activity cycle. In this white paper, the key science cases and their technical requirements for AtLAST are discussed.


Observations of our Sun and other stars at wavelengths of around one millimeter, i.e. in the range between infrared and radio waves, present a valuable complementary perspective. Despite significant technological advancements, certain critical aspects necessitate diagnostic capabilities not offered by current observatories. The proposed Atacama Large Aperture Submillimeter Telescope (AtLAST), featuring a 50-meter aperture and slated for construction at a high altitude in Chile's Atacama desert, promises to address these observational needs. Equipped with novel detectors that would cover a wide frequency range, AtLAST could unlock a plethora of scientific studies contributing to a better understanding of our host star. Simultaneous observations over a broad frequency range at rapid succession would enable the imaging of different layers of the Sun, thus elucidating the three-dimensional thermal and magnetic structure of the solar atmosphere and providing important clues for many long-standing central questions such as how the outermost layers of the Sun are heated to very high temperatures, the nature of large-scale structures like prominences, and how flares and coronal mass ejections, i.e. enormous eruptions, are produced. The latter is of particular interest to modern society due to the potentially devastating impact on the technological infrastructure we depend on today. Another unique possibility would be to study the Sun's long-term evolution in this wavelength range, which would yield important insights into its activity cycle. Moreover, the Sun serves as a fundamental reference for other stars as, due to its proximity, it is the only star that can be investigated in such detail. The results for the Sun would therefore have direct implications for understanding other stars and their impact on exoplanets. This article outlines the key scientific objectives and technical requirements for solar observations with AtLAST.

15.
Int J Pharm ; 630: 122465, 2023 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-36476664

RESUMEN

Nitric oxide (NO) is an important endogenous molecule that plays several roles in biological systems. NO is synthesized in human skin by three isoforms of nitric oxide synthase (NOS) and, depending on the produced NO concentration, it can actuate in wound healing, dermal vasodilation, or skin defense against different pathogens, for example. Besides being endogenously produced, NO-based pharmacological formulations have been developed for dermatological applications targeting diverse pathologies such as bacterial infection, wound healing, leishmaniasis, and even esthetic issues such as acne and skin aging. Recent strategies focus mainly on developing smart NO-releasing nanomaterials/biomaterials, as they enable a sustained and targeted NO release, promoting an improved therapeutic effect. This review aims to overview and discuss the main mechanisms of NO in human skin, the recent progress in the field of dermatological formulations containing NO, and their application in several skin diseases, highlighting promising advances and future perspectives in the field.


Asunto(s)
Óxido Nítrico , Enfermedades de la Piel , Humanos , Óxido Nítrico/farmacología , Materiales Biocompatibles , Piel , Cicatrización de Heridas , Enfermedades de la Piel/tratamiento farmacológico
16.
Pharmaceutics ; 15(3)2023 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-36986881

RESUMEN

Colorectal cancer is occasionally called colon or rectal cancer, depending on where cancer begins to form, and is the second leading cause of cancer death among both men and women. The platinum-based [PtCl(8-O-quinolinate)(dmso)] (8-QO-Pt) compound has demonstrated encouraging anticancer activity. Three different systems of 8-QO-Pt-encapsulated nanostructured lipid carriers (NLCs) with riboflavin (RFV) were investigated. NLCs of myristyl myristate were synthesized by ultrasonication in the presence of RFV. RFV-decorated nanoparticles displayed a spherical shape and a narrow size dispersion in the range of 144-175 nm mean particle diameter. The 8-QO-Pt-loaded formulations of NLC/RFV with more than 70% encapsulation efficiency showed sustained in vitro release for 24 h. Cytotoxicity, cell uptake, and apoptosis were evaluated in the HT-29 human colorectal adenocarcinoma cell line. The results revealed that 8-QO-Pt-loaded formulations of NLC/RFV showed higher cytotoxicity than the free 8-QO-Pt compound at 5.0 µM. All three systems exhibited different levels of cellular internalization. Moreover, the hemotoxicity assay showed the safety profile of the formulations (less than 3.7%). Taken together, RFV-targeted NLC systems for drug delivery have been investigated for the first time in our study and the results are promising for the future of chemotherapy in colon cancer treatment.

17.
Pharmaceutics ; 15(2)2023 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-36839745

RESUMEN

Bacterial cellulose (BC) is produced by several microorganisms as extracellular structures and can be modified by various physicochemical and biological strategies to produce different cellulosic formats. The main advantages of BC for biomedical applications can be summarized thus: easy moldability, purification, and scalability; high biocompatibility; and straightforward tailoring. The presence of a high amount of free hydroxyl residues, linked with water and nanoporous morphology, makes BC polymer an ideal candidate for wound healing. In this frame, acute and chronic wounds, associated with prevalent pathologies, were addressed to find adequate therapeutic strategies. Hence, the main characteristics of different BC structures-such as membranes and films, fibrous and spheroidal, nanocrystals and nanofibers, and different BC blends, as well as recent advances in BC composites with alginate, collagen, chitosan, silk sericin, and some miscellaneous blends-are reported in detail. Moreover, the development of novel antimicrobial BC and drug delivery systems are discussed.

18.
Anal Methods ; 15(9): 1230-1240, 2023 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-36807654

RESUMEN

Voriconazole (VCZ) is a triazolic drug used to treat serious fungal infections and invasive mycosis and has also been more recently used as a generic antifungal treatment. However, VCZ therapies can cause undesirable side effects and doses must be carefully monitored before administration to avoid or reduce severe toxic effects. Analytical techniques used to quantify VCZ are mostly based on HPLC/UV and often associated with multiple technical steps as well as expensive equipment. The present work aimed to develop an accessible and affordable spectrophotometric technique in the visible range (λ = 514 nm) for the simple quantification of VCZ. The technique was based on VCZ-induced reduction of thionine (TH, red) to leucothionine (LTH, colorless) under alkaline conditions. The reaction showed a linear correlation over the range of 1.00 µg mL-1 to 60.00 µg mL-1 at room temperature, the limits of detection and quantification being 1.93 µg mL-1 and 6.45 µg mL-1, respectively. VCZ degradation products (DPs) according to 1H and 13C-NMR spectrometric determinations not only showed good agreement with the ones previously reported (DP1 and DP2 - T. M. Barbosa, G. A. Morris, M. Nilsson, R. Rittner and C. F. Tormena, RSC Adv., 2017, DOI: 10.1039/c7ra03822d), but also revealed a new degradation product (DP3). Mass spectrometry not only confirmed the presence of LTH as a result of the VCZ DP-induced TH reduction, but also revealed the formation of a novel and stable Schiff base as a reaction product between DP1 and LTH. The latter finding became significant as it stabilizes the reaction for quantification purposes, by hindering LTH ↔TH redox reversibility. This analytical method was then validated according to the ICH Q2 (R1) guidelines, and additionally, it could be demonstrated as applicable for the reliable VCZ quantification in commercially available tablets. Importantly, it also represents a useful tool for detecting toxic threshold concentrations in human plasma from VCZ-treated patients, alerting when these risky limits are exceeded. In this way, this technique independent from sophisticated equipment, highly qualifies as a low-cost, reproducible, trustable, and non-laborious alternative method for VCZ measurements from different matrices.


Asunto(s)
Antifúngicos , Fenotiazinas , Humanos , Voriconazol/uso terapéutico , Preparaciones Farmacéuticas , Antifúngicos/uso terapéutico
19.
Pharmaceutics ; 15(8)2023 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-37631258

RESUMEN

Plant and herbal essential oils (EOs) offer a wide range of pharmacological actions that include anticancer effects. Here, we evaluated the cytotoxic activity of EO from Lippia alba (chemotype linalool), L. alba (chemotype dihydrocarvone, LaDEO), Clinopodium nepeta (L.) Kuntze (CnEO), Eucalyptus globulus, Origanum × paniculatum, Mentha × piperita, Mentha arvensis L., and Rosmarinus officinalis L. against human lung (A549) and colon (HCT-116) cancer cells. The cells were treated with increasing EO concentrations (0-500 µL/L) for 24 h, and cytotoxic activity was assessed. LaDEO and CnEO were the most potent EOs evaluated (IC50 range, 145-275 µL/L). The gas chromatography-mass spectrometry method was used to determine their composition. Considering EO limitations as therapeutic agents (poor water solubility, volatilization, and oxidation), we evaluated whether LaDEO and CnEO encapsulation into solid lipid nanoparticles (SLN/EO) enhanced their anticancer activity. Highly stable spherical SLN/LaDEO and SLN/CnEO SLN/EO were obtained, with a mean diameter of 140-150 nm, narrow size dispersion, and Z potential around -5mV. EO encapsulation strongly increased their anticancer activity, particularly in A549 cells exposed to SLN/CnEO (IC50 = 66 µL/L CnEO). The physicochemical characterization, biosafety, and anticancer mechanisms of SLN/CnEO were also evaluated in A549 cells. SLN/CnEO containing 97 ± 1% CnEO was highly stable for up to 6 months. An increased in vitro CnEO release from SLN at an acidic pH (endolysosomal compartment) was observed. SLN/CnEO proved to be safe against blood components and non-toxic for normal WI-38 cells at therapeutic concentrations. SLN/CnEO substantially enhanced A549 cell death and cell migration inhibition compared with free CnEO.

20.
J Funct Biomater ; 14(9)2023 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-37754878

RESUMEN

In this work, scaffolds based on poly(hydroxybutyrate) (PHB) and micronized bacterial cellulose (BC) were produced through 3D printing. Filaments for the printing were obtained by varying the percentage of micronized BC (0.25, 0.50, 1.00, and 2.00%) inserted in relation to the PHB matrix. Despite the varying concentrations of BC, the biocomposite filaments predominantly contained PHB functional groups, as Fourier transform infrared spectroscopy (FTIR) demonstrated. Thermogravimetric analyses (i.e., TG and DTG) of the filaments showed that the peak temperature (Tpeak) of PHB degradation decreased as the concentration of BC increased, with the lowest being 248 °C, referring to the biocomposite filament PHB/2.0% BC, which has the highest concentration of BC. Although there was a variation in the thermal behavior of the filaments, it was not significant enough to make printing impossible, considering that the PHB melting temperature was 170 °C. Biological assays indicated the non-cytotoxicity of scaffolds and the provision of cell anchorage sites. The results obtained in this research open up new paths for the application of this innovation in tissue engineering.

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