Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 43
Filtrar
Más filtros

País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Pharm Dev Technol ; 27(5): 615-624, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35786299

RESUMEN

Zidovudine (AZT) has been widely used alone or in combination with other antiretroviral drugs for the treatment of human immunodeficiency virus. Its erratic oral bioavailability necessitates frequent administration of high doses, resulting in severe side effects. In this study, the design of mucoadhesive solid dispersions (SDs) based on chitosan (CS) and hypromellose phthalate (HP) was rationalized as a potential approach to modulate AZT physicochemical and pharmaceutical properties. SDs were prepared at different drug:polymer ratios, using an eco-friendly technique, which avoids the use of organic solvents. Particles with diameter from 56 to 73 µm and negative zeta potentials (-27 to -32 mV) were successfully prepared, achieving high drug content. Infrared spectroscopy revealed interactions between polymers but no interactions between the polymers and AZT. Calorimetry and X-ray diffraction analyses showed that AZT was amorphized into the SDs. The mucoadhesive properties of SDs were evidenced, and the control of AZT release rates from the matrix was achieved, mainly in acid media. The simple, low-cost, and scalable technology proposed for production of SDs as a carrier platform for AZT is an innovative approach, and it proved to be a feasible strategy for modulation the physico-chemical, mucoadhesive, and release properties of the drug.


Asunto(s)
Quitosano , Quitosano/química , Portadores de Fármacos/química , Humanos , Derivados de la Hipromelosa , Metilcelulosa/análogos & derivados , Polímeros/química , Solubilidad , Zidovudina/química
2.
Drug Dev Ind Pharm ; 47(12): 1904-1914, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35236214

RESUMEN

Nanostructured polyelectrolyte complexes (nano PECs) were obtained by polyelectrolyte complexation technique from chitosan (CS) and sodium alginate (SA). Different polymer proportions were tested, as well as the addition order and homogenization type, to assess the influence on the nano PECs characteristics. The spherical shape and nanometric scale of the systems were observed by scanning electron microscopy (SEM). Nano PECs size, PDI, and zeta potential (ZP) ranged from 252 to 616 nm, from 0.22 to 0.73 and -50 to 30 mV, respectively. The increase of polymer proportion and the ultra-turrax homogenization led to the enlargement of particles size and PDI. However, no influence was observed on the ZP. The NP1s-Rb and NP4s-Rb, obtained through the sonicator with rifampicin (RIF) added before the CS and SA complexation, were selected due to the most promising characteristics of diameter (301 and 402 nm), PDI (0.27 and 0.26), and RIF incorporation (78 and 69%). The release profiles of RIF incorporated in both nano PECs were similar, with a sustained release of the drug for 180 min in phosphate buffer pH 7.2. The Weibull and the Korsmeyer-Peppas models better describe the RIF release from NP1s-Rb and NP4s-Rb, respectively, demonstrating that the release process was driven by different mechanism according to the particle composition. The nano PECs were lyophilized to prolong it stability and for possible nebulization. The addition of dextrose to the system allowed for resuspension after lyophilization. Therefore, with the results obtained, the incorporation of RIF in nano PECs based on CS and SA presents a promising system for the treatment of tuberculosis.


Asunto(s)
Quitosano , Tuberculosis , Alginatos/química , Quitosano/química , Portadores de Fármacos/química , Humanos , Polielectrolitos/química , Polímeros , Rifampin
3.
Drug Dev Ind Pharm ; 46(2): 236-245, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31928345

RESUMEN

Nanoparticles based on gellan gum/pectin blends were designed for colon-targeted release of resveratrol (RES). Their impact on drug release rates and permeability were evaluated using Caco-2 cell model and mucus secreting triple co-culture model. Polymeric nanoparticles (PNP) were successfully prepared by nebulization/ionotropic gelation, achieving high drug loading (>80%). PNP were spherical with a low positive charge density (+5mV) and exhibited diameters of around 330 nm. Developed PNP were able to promote effective modulation of drug release rates, so that only 3% of RES was released in acidic media over 2 h, and, in pH 6.8, the drug was released in a sustained manner, reaching 85% in 30 h. The permeability of RES-loaded PNP in the Caco-2 model was 0.15%, while in the triple co-culture model, in the presence of mucus, it reached 5.5%. The everted gut sac experiment corroborated the low permeability of RES-loaded PNP in the presence or absence of mucus and highlighted their high ability to interact with the intestinal tissue. Results indicate that the novel PNP developed in this work are safe and promising carriers for controlled delivery of RES at the colon.


Asunto(s)
Colon/efectos de los fármacos , Nanopartículas/administración & dosificación , Nanopartículas/química , Pectinas/química , Polisacáridos Bacterianos/química , Resveratrol/administración & dosificación , Resveratrol/química , Administración Oral , Animales , Células CACO-2 , Línea Celular Tumoral , Portadores de Fármacos/química , Liberación de Fármacos , Células HT29 , Humanos , Concentración de Iones de Hidrógeno , Mucosa Intestinal/metabolismo , Masculino , Moco/metabolismo , Tamaño de la Partícula , Permeabilidad/efectos de los fármacos , Ratas , Ratas Wistar
4.
Pharm Dev Technol ; 25(2): 159-167, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31623500

RESUMEN

Films of gellan gum:pectin blends were prepared by solvent casting method. Gellan gum:pectin mass ratios were varied (4:1; 1:1; 1:4) at different concentrations (3% or 4%) and glycerol was used as plasticizer (1 or 2%). The films were thin (18-30 µm), translucent, flexible, and homogeneous. The surface pH was suitable for buccal application. All films reached high mechanical resistance and the mucoadhesive ability of them was evidenced. High ratio of gellan gum improved the mechanical resistance and the mucoadhesion of the films as well as the control of drug release rates. The films did not disintegrate in simulate saliva up to 24 h and curcumin release could be sustained up to 12 h. The set of data evidence that the films designed in this work represent a potential platform for buccal drug delivery.


Asunto(s)
Pectinas/química , Polisacáridos Bacterianos/química , Administración Bucal , Curcumina/administración & dosificación , Curcumina/química , Preparaciones de Acción Retardada/química , Sistemas de Liberación de Medicamentos/métodos , Liberación de Fármacos/efectos de los fármacos , Boca/efectos de los fármacos , Mucosa Bucal/efectos de los fármacos , Plastificantes/química
5.
Drug Dev Ind Pharm ; 43(10): 1656-1668, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28489424

RESUMEN

This work aimed to develop a calcium alginate hydrogel as a pH responsive delivery system for polymyxin B (PMX) sustained-release through the vaginal route. Two samples of sodium alginate from different suppliers were characterized. The molecular weight and M/G ratio determined were, approximately, 107 KDa and 1.93 for alginate_S and 32 KDa and 1.36 for alginate_V. Polymer rheological investigations were further performed through the preparation of hydrogels. Alginate_V was selected for subsequent incorporation of PMX due to the acquisition of pseudoplastic viscous system able to acquiring a differential structure in simulated vaginal microenvironment (pH 4.5). The PMX-loaded hydrogel (hydrogel_PMX) was engineered based on polyelectrolyte complexes (PECs) formation between alginate and PMX followed by crosslinking with calcium chloride. This system exhibited a morphology with variable pore sizes, ranging from 100 to 200 µm and adequate syringeability. The hydrogel liquid uptake ability in an acid environment was minimized by the previous PECs formation. In vitro tests evidenced the hydrogels mucoadhesiveness. PMX release was pH-dependent and the system was able to sustain the release up to 6 days. A burst release was observed at pH 7.4 and drug release was driven by an anomalous transport, as determined by the Korsmeyer-Peppas model. At pH 4.5, drug release correlated with Weibull model and drug transport was driven by Fickian diffusion. The calcium alginate hydrogels engineered by the previous formation of PECs showed to be a promising platform for sustained release of cationic drugs through vaginal administration.


Asunto(s)
Alginatos/química , Cloruro de Calcio/química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Polielectrolitos/química , Polímeros/química , Administración Intravaginal , Alginatos/administración & dosificación , Química Farmacéutica , Difusión , Liberación de Fármacos , Ácido Glucurónico/administración & dosificación , Ácido Glucurónico/química , Ácidos Hexurónicos/administración & dosificación , Ácidos Hexurónicos/química , Hidrogel de Polietilenoglicol-Dimetacrilato/administración & dosificación , Concentración de Iones de Hidrógeno
6.
Drug Dev Ind Pharm ; 42(8): 1283-90, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26616390

RESUMEN

Gellan gum microspheres were obtained by ionotropic gelation technique, using the trivalent ion Al(3+). The percentage of entrapment efficiency ranged from 48.76 to 87.52% and 2(2) randomized full factorial design demonstrated that both the increase of polymer concentration and the decrease of crosslinker concentration presented a positive effect in the amount of encapsulated drug. Microspheres size and circularity ranged from 700.17 to 938.32 µm and from 0.641 to 0.796 µm, respectively. The increase of polymer concentration (1-2%) and crosslinker concentration (3-5%) led to the enlargement of particle size and circularity. However, the association of increased crosslinker concentration and reduced polymer content made the particles more irregular. In vitro and ex vivo tests evidenced the high mucoadhesiveness of microspheres. The high liquid uptake ability of the microspheres was demonstrated and the pH variation did not affect this parameter. Drug release was pH dependent, with low release rates in acid pH (42.40% and 44.93%) and a burst effect in phosphate buffer pH (7.4). The Weibull model had the best correlation with the drug release data, demonstrating that the release process was driven by a complex mechanism involving the erosion and swelling of the matrix or by non-Fickian diffusion.


Asunto(s)
Iones/química , Polímeros/química , Polisacáridos Bacterianos/química , Animales , Sistemas de Liberación de Medicamentos/métodos , Liberación de Fármacos , Concentración de Iones de Hidrógeno , Mucosa Intestinal/metabolismo , Microesferas , Tamaño de la Partícula , Porcinos
7.
Rev Gaucha Enferm ; 44: e20220125, 2023.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-37436220

RESUMEN

OBJECTIVE: To know the perception of academics and nursing staff about the extension project "Walking through the hospital". METHOD: Qualitative study conducted in a Brazilian university hospital from November/2019 to April/2022 with nursing students and professionals participating in a university extension project. Data were collected using instruments on the Google Forms® platform and submitted to Content Thematic Analysis. The project was approved by the Ethics Committee. RESULTS: Fifteen academics, four nurses and six nursing technicians participated in the study. Four categories emerged from the analysis: "Knowing the hospital environment/dynamics", "Articulation between theory and practice","Bond between academics and health care professionals" and "Work process in the unit". FINAL CONSIDERATIONS: The findings highlight the importance of university extension in providing knowledge and experienceof hospital clinical practice, which can contribute to strengthening teaching and academic training in nursing.


Asunto(s)
Personal de Enfermería en Hospital , Personal de Enfermería , Estudiantes de Enfermería , Humanos , Investigación Cualitativa , Hospitales Universitarios , Docentes de Enfermería
8.
Int J Pharm ; 635: 122792, 2023 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-36863543

RESUMEN

Lipid core nanocapsules (NCs) coated with multiple polymer layers were rationally designed as a potential approach for the colonic delivery of camptothecin (CPT). Chitosan (CS), hyaluronic acid (HA) and hypromellose phthalate (HP) were selected as coating materials, to modulate the mucoadhesive and permeability properties of CPT regarding the improvement of local and targeted action in the colon cancer cells. NCs were prepared by emulsification/solvent evaporation method and coated with multiple polymer layers by polyelectrolyte complexation technique. NCs exhibited spherical shape, negative zeta potential, and size ranged from 184 to 252 nm. The high efficiency of CPT incorporation (>94%) was evidenced. The ex vivo permeation assay showed that nanoencapsulation reduced the permeation rate of CPT through the intestinal mucosa by up to 3.5 times, and coating with HA and HP reduced the permeation percentage by 2 times when compared to NCs coated only with CS. The mucoadhesive capacity of NCs was demonstrated in gastric and enteric pH. Nanoencapsulation did not reduce the antiangiogenic activity of CPT and, additionally, it was observed that nanoencapsulation resulted in localized antiangiogenic action of CPT.


Asunto(s)
Quitosano , Nanocápsulas , Nanocápsulas/química , Polímeros/química , Quitosano/química , Camptotecina/farmacología , Camptotecina/química , Lípidos/química
9.
Rev Gaucha Enferm ; 43: e20220228, 2023.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-36888743

RESUMEN

OBJECTIVE: To understand the experiences of family members of people who committed suicide and describe the typologies of the biographical cases through the approach of biographical interviews and analysis. METHOD: Qualitative research, with a reconstructive approach to Rosenthal's biographical cases, based on Schutz's phenomenological sociology. Biographical narrative interviews were conducted between November/2017 and February/2018, in a city in southern Brazil, with eleven family members of people who survived suicide. The analysis followed the phases of Rosenthal's biographical case reconstruction. RESULTS: The reconstruction of two biographical cases were presented. The results point to two distinct typologies: maternal role in the face of suicide and social stigmatization; use of the cultural meaning of family as a resource for coping with suicide. CONCLUSION: It is important to listen to these family members, as the understanding of their experiences can support health professionals in the implementation of care actions.


Asunto(s)
Familia , Suicidio , Humanos , Adaptación Psicológica , Investigación Cualitativa , Brasil
10.
Parasit Vectors ; 16(1): 303, 2023 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-37644584

RESUMEN

BACKGROUND: The successful use of semiochemicals to attract insects to traps is based on research on the most suitable compounds and their release profiles over time. Based on the group's promising results, matrices with a more adequate release profile and more eco-friendly properties for the release of 1-hexanol were developed. To use a more suitable prototype in the field, the most promising systems were added to a capsule and evaluated in a wind tunnel. Behavioral experiments were performed using the sand fly species, Lutzomyia longipalpis, to evaluate the efficacy of the proposed system. METHODS: Different delivery systems were developed by varying the polymer (gellan gum and pectin) ratio, crosslinker (aluminum chloride) concentration, and glutaraldehyde removal.The delivery systems were loaded with 1-hexanol, and their release profiles were evaluated using gravimetric analysis under ambient and high-humidity conditions. When the matrix system was placed inside a plastic container, modulations in the active release profile were observed and the system could be reused. Actid attraction behaviors of the sand fly species, Lu. longipalpis, were evaluated in a wind tunnel when exposed to 1-hexanol-loaded release systems at different times. RESULTS: Among the four formulations evaluated, System 2 (gellan gum and pectin in a 1:1 ratio with 5% aluminum chloride) exhibited the most promising release profile, with greater uniformity and longer compound release time. The maximum 1-hexanol release uniformity was achieved over a longer time, mainly every 24 h, under both ambient and high-humidity conditions. System 2 can be reused at least once with the same structure. The wind tunnel trials exhibited efficient activation and attraction of Lu. longipalpis to 1-hexanol after 24, 48, and 72 h in System 2 placed inside the capsules. CONCLUSIONS: The polymeric matrix supplemented with 1-hexanol and introduced in plastic capsules showed promising results in attracting sand flies. This system can be used as a solution for other attractive compounds as well as in other applications where their release needs to be controlled or prolonged.


Asunto(s)
Phlebotomus , Psychodidae , Animales , Cloruro de Aluminio , Cápsulas , Polímeros , Plásticos , Pectinas
11.
Pharmaceuticals (Basel) ; 16(8)2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37631009

RESUMEN

BACKGROUND: Vulvovaginal candidiasis (VVC) is a worldwide public health problem caused predominantly by the opportunistic polymorphic fungus Candida albicans, whose pathogenicity is associated with its morphological adaptability. To potentiate the treatment of C. albicans-induced VVC by an alternative method as photodynamic therapy (PDT), hypericin (Hy), a potent photosensitizer compound was incorporated into a nanostructured lipid carrier (NLC) and dispersed in hydrogel (HG). METHODS: After preparation of the sonication process, an NLC loaded with Hy was dispersed in HG based on Poloxamer 407 and chitosan obtaining Hy.NLC-HG. This hydrogel system was physically and chemically characterized and its in vitro and in vivo photodynamic and antifungal effects were evaluated. RESULTS: Through scanning electron microscopy, it was possible to observe a hydrogel system with a porous polymeric matrix and irregular microcavities. The Hy.NLC-HG system showed mucoadhesive properties (0.45 ± 0.08 N) and a satisfactory injectability (15.74 ± 4.75 N.mm), which indicates that it can be easily applied in the vaginal canal, in addition to a controlled and sustained Hy release profile from the NLC-HG of 28.55 ± 0.15% after 720 min. The in vitro antibiofilm assay significantly reduced the viability of C. albicans (p < 0.001) by 1.2 log10 for Hy.NLC-HG/PDT and 1.9 log10 for PS/PDT, Hy.NLC/PDT, and free RB/PDT, compared to the PBS/PDT negative control. The in vivo antifungal evaluation showed that animals treated with the vaginal cream (non-PDT) and the PDT-mediated Hy.NLC-HG system showed a significant difference of p < 0.001 in the number of C. albicans colonies (log) in the vaginal canal, compared to the inoculation control group. CONCLUSIONS: Thus, we demonstrate the pharmaceutical, antifungal, and photodynamic potential of hydrogel systems for Hy vaginal administration.

12.
Rev Esc Enferm USP ; 56: e20210569, 2022.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-35635790

RESUMEN

OBJECTIVE: to assess the effects of an educational intervention on smoking cessation aimed at the nursing team. METHOD: this is a quasi-experimental study with 37 nursing professionals from a Brazilian hospital from May/2019 to December/2020. The intervention consisted of training nursing professionals on approaches to hospitalized smokers divided into two steps, the first, online, a prerequisite for the face-to-face/videoconference. The effect of the intervention was assessed through pre- and post-tests completed by participants. Smokers' medical records were also analyzed. For analysis, McNemar's chi-square test was used. RESULTS: there was an increase in the frequency of actions aimed at smoking cessation after the intervention. Significant differences were found in guidelines related to disclosure to family members of their decision to quit smoking and the need for support, encouragement of abstinence after hospital discharge, and information on tobacco cessation and relapse strategies. CONCLUSION: the educational intervention proved to be innovative and with a great capacity for disseminating knowledge. The post-test showed a positive effect on the frequency of actions aimed at smoking cessation implemented by the nursing team.


Asunto(s)
Fumadores , Cese del Hábito de Fumar , Hospitalización , Humanos , Alta del Paciente , Fumar
13.
J Mycol Med ; 32(4): 101296, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35660541

RESUMEN

INTRODUCTION AND AIM: The indiscriminate use and adverse effects of the main conventional antifungal agents compromise the effectiveness of treating vulvovaginal candidiasis (VVC), mainly caused by the species Candida albicans. This study evaluated the effectiveness of photodynamic therapy (PDT) and the in vitro and in vivo anti-candida potential of the hypericin (HYP)-loaded nanostructured lipid carriers (NLC). MATERIALS AND METHODS: Empty NLC and NLC-HYP were characterized by the dynamic light scattering technique and transmission electron microscopy to evaluate the average particle size distribution and its morphologies. The in vitro inhibition photodynamic effect of the systems was tested to reduce the planktonic viability of C. albicans. The therapeutic assay photodynamic of the systems was performed to treat VVC in mice. RESULTS: Empty NLC and NLC-HYP presented values of average hydrodynamic diameter, polydispersity index, and ζ-potential from 136 to 133 nm, 0.16 to 0.22, and -18 to -30 mV, respectively, on day 30. Microscopically, the systems showed spherical morphologies and nanoscale particles. Furthermore, in the in vitro inhibition assay, the treatment of PDT with NLC-HYP (NLC-HYP+) showed a significant reduction of the C. albicans planktonic viability compared to YNB negative control after 5 min of LED light irradiation. In the in vivo therapeutic assay, the antifungal group (vaginal antifungal cream) and NLC-HYP+ evaluated in the dark and by PDT, respectively, had a significant log10 reduction in fungal burden compared to the infected group on day 8 of the VVC treatment. CONCLUSION: Due to the in vitro and in vivo anti-candida potential, PDT-mediated systems can be an effective strategy in VVC therapy.


Asunto(s)
Candidiasis Vulvovaginal , Fotoquimioterapia , Humanos , Femenino , Ratones , Animales , Candidiasis Vulvovaginal/tratamiento farmacológico , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Candida albicans , Candida , Lípidos/farmacología , Lípidos/uso terapéutico
14.
Pharmaceutics ; 13(3)2021 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-33808670

RESUMEN

Polymer blends of gellan gum (GG)/retrograded starch(RS) and GG/pectin (P) were cross-linked with calcium, aluminum, or both to prepare mucoadhesive microparticles as oral carriers of drugs or nano systems. Cross-linking with different cations promoted different effects on each blend, which can potentially be explored as novel strategies for modulating physical-chemical and mucoadhesive properties of microparticles. Particles exhibited spherical shapes, diameters from 888 to 1764 µm, and span index values lower than 0.5. Blends of GG:P cross-linked with aluminum resulted in smaller particles than those obtained by calcium cross-linking. GG:RS particles exhibited larger sizes, but cross-linking this blend with calcium promoted diameter reduction. The uptake rates of acid medium were lower than phosphate buffer (pH 6.8), especially GG:RS based particles cross-linked with calcium. On the other hand, particles based on GG:P cross-linked with calcium absorbed the highest volume of acid medium. The percentage of systems erosion was higher in acid medium, but apparently occurred in the outermost layer of the particle. In pH 6.8, erosion was lower, but caused expressive swelling of the matrixes. Calcium cross-linking of GG:RS promoted a significantly reduction on enzymatic degradation at both pH 1.2 and 6.8, which is a promising feature that can provide drug protection against premature degradation in the stomach. In contrast, GG:P microparticles cross-linked with calcium suffered high degradation at both pH values, an advantageous feature for quickly releasing drugs at different sites of the gastrointestinal tract. The high mucoadhesive ability of the microparticles was evidenced at both pH values, and the Freundlich parameters indicated stronger particle-mucin interactions at pH 6.8.

15.
Rev Gaucha Enferm ; 42(spe): e20200183, 2021.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-33566890

RESUMEN

OBJECTIVE: To develop and validate the content of an educational intervention on smoking cessation for Nursing professionals using a Blended Learning approach. METHOD: A development and validation study by consensus of experts of the "Smoking Cessation" course for Nursing professionals on approaches to the smoking patient carried out in 2018. For refinement and validation of the final content, a convenience sample was made up of 12 professionals with expertise in the subject natter and an 80% consensus among the participants was considered. RESULTS: The construction of the course involved the choice of subjects, production, and content validation. As a teaching strategy, Blended Learning was used, which has an interactive online stage and a face-to-face meeting to discuss concepts and exchange experiences. CONCLUSION: The course using a Blended Learning method proved to be innovative, low-cost, and with great capacity for disseminating knowledge, being an important ally to permanent education in health.


Asunto(s)
Cese del Hábito de Fumar , Curriculum , Escolaridad , Humanos , Aprendizaje
16.
Carbohydr Polym ; 254: 117444, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33357914

RESUMEN

Nanostructured polyelectrolyte complexes (nano PECs) based on biopolymers are an important technological strategy to target drugs to the action and/or absorption site in a more effective way. In this work, computational studies were performed to predict the ionization, spatial arrangement and interaction energies of chitosan (CS), hyaluronic acid (HA), and hypromellose phthalate (HP), for the design of nano PEC carriers for methotrexate (MTX). The optimal pH range (5.0-5.5) for preparing nano PECs was selected by experimental and computational methodologies, favoring the polymers interactions. CS, HA, HP and MTX addition order was also rationalized, maximizing their interactions and MTX entrapment. Spherical nano-sized particles (256-575 nm, by dynamic light scattering measurement) with positive surface charge (+25.5 to +29.2 mV) were successfully prepared. The MTX association efficiency ranged from 20 to 32 %. XRD analyses evidenced the formation of a new material with an organized structure, in relation to raw polymers.


Asunto(s)
Antimetabolitos Antineoplásicos/química , Quitosano/química , Portadores de Fármacos , Ácido Hialurónico/química , Metotrexato/química , Metilcelulosa/análogos & derivados , Nanoestructuras/química , Composición de Medicamentos/métodos , Humanos , Concentración de Iones de Hidrógeno , Metilcelulosa/química , Nanoestructuras/ultraestructura , Tamaño de la Partícula , Polielectrolitos/química , Soluciones , Electricidad Estática , Termodinámica
17.
Int J Biol Macromol ; 178: 558-568, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33577816

RESUMEN

Two samples of N-(2-hydroxy)-propyl-3-trimethylammonium, O-palmitoyl chitosan (DPCat) with different average degrees of quaternization named as DPCat35 (DQ¯ = 35%) and DPCat80 (DQ¯ = 80%), were successfully synthesized by reacting glycidyltrimethylammonium chloride (GTMAC) with O-palmitoyl chitosan (DPCh) derivative (DS¯ = 12%). Such amphiphilic derivatives of chitosan were fully water-soluble at 1.0 < pH < 12.0 and showed significant electrostatic stability enhancement of a self-assembly micellar nanostructure (100-320 nm) due to its positively-charged out-layer. In vitro mucoadhesive and cytotoxicity essays toward healthy fibroblast cells (Balb/C 3T3 clone A31 cell), human prostate cancer (DU145) and liver cancer (HepG2/C3A) cell lines revealed that the biological properties of DPCat derivatives were strongly dependent on DQ¯. Additionally, DPCat35 had better interactions with the biological tissue and with mucin glycoproteins at pH 7.4 as well as exhibited potential to be used on the development of drug delivery systems for prostate and liver cancer treatment.


Asunto(s)
Quitosano , Sistemas de Liberación de Medicamentos , Compuestos Epoxi/química , Compuestos de Amonio Cuaternario/química , Animales , Células 3T3 BALB , Quitosano/síntesis química , Quitosano/química , Quitosano/farmacología , Células Hep G2 , Humanos , Neoplasias Hepáticas/tratamiento farmacológico , Masculino , Ratones , Neoplasias de la Próstata/tratamiento farmacológico , Electricidad Estática
18.
Int J Pharm ; 603: 120714, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-34015380

RESUMEN

Mutations on the epidermal growth factor receptor (EGFR), induction of angiogenesis, and reprogramming cellular energetics are all biological features acquired by tumor cells during tumor development, and also known as the hallmarks of cancer. Targeted therapies that combine drugs that are capable of acting against such concepts are of great interest, since they can potentially improve the therapeutic efficacy of treatments of complex pathologies, such as glioblastoma (GBM). However, the anatomical location and biological behavior of this neoplasm imposes great challenges for targeted therapies. A novel strategy that combines alpha-cyano-4-hydroxycinnamic acid (CHC) with the monoclonal antibody cetuximab (CTX), both carried onto a nanotechnology-based delivery system, is herein proposed for GBM treatment via nose-to-brain delivery. The biological performance of Poly (D,L-lactic-co-glycolic acid)/chitosan nanoparticles (NP), loaded with CHC, and conjugated with CTX by covalent bonds (conjugated NP) were extensively investigated. The NP platforms were able to control CHC release, indicating that drug release was driven by the Weibull model. An ex vivo study with nasal porcine mucosa demonstrated the capability of these systems to promote CHC and CTX permeation. Blot analysis confirmed that CTX, covalently associated to NP, impairs EGRF activation. The chicken chorioallantoic membrane assay demonstrated a trend of tumor reduction when conjugated NP were employed. Finally, images acquired by fluorescence tomography evidenced that the developed nanoplatform was effective in enabling nose-to-brain transport upon nasal administration. In conclusion, the developed delivery system exhibited suitability as an effective novel co-delivery approaches for GBM treatment upon intranasal administration.


Asunto(s)
Glioblastoma , Nanopartículas , Preparaciones Farmacéuticas , Administración Intranasal , Animales , Encéfalo , Línea Celular Tumoral , Sistemas de Liberación de Medicamentos , Glioblastoma/tratamiento farmacológico , Porcinos
19.
J Pharm Biomed Anal ; 190: 113540, 2020 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-32846401

RESUMEN

Accumulating evidence has been suggesting that combining two or more anticancer drugs can provide additive or synergistic effects, improving therapeutic efficacy and delaying resistance. Nowadays, advances in nanotechnology-based delivery systems have enabled the association of different drugs into a single carrier and provided therapeutic gains to the proposed regimen. However, a new strategy also requires innovative analytical approaches that assess loading capacity, biological performance, and also comprehend the mechanisms of action. Alpha-cyano-4-hydroxycinnamic acid (CHC) and the monoclonal antibody (mAb) cetuximab (CTX) are explored worldwide for their therapeutic benefits against multiple cancer cells. The present work aims to develop and validate a new method for simultaneous quantification of CHC and CTX in nanoparticulate systems by using reverse phase high-performance liquid chromatography (RP-HPLC) with ultraviolet (UV) detection for CHC, and fluorescence detection for CTX. This method was designed following the guidelines of the International Conference on Harmonization ICH Q2 (R1) and the Food and Drug Administration (FDA) - Guidance for Bioanalytical Method Validation. Chromatographic separation was performed on a C18 column with the mobile phase composed by water, 0.1 % (v/v) trifluoroacetic acid (TFA) and acetonitrile (ACN)-0.1 % TFA on gradient mode at a flow rate of 0.6 mL/min. The performance of the present method was evaluated by system suitability; therefore, linearity, accuracy, precision, detection, limit of detection / limit of quantification, and robustness were also highlighted. Specificity was demonstrated by the chromatographic analyses of CHC and CTX, subjected to several informative stress conditions. The developed method was also successfully used for the first time to quantify the CHC and CTX content in poly(lactic-co-glycolic acid)-based nanoparticles. In conclusion, this new and rapid method presented acceptable analytical performance and can be helpful to simultaneously quantify CHC and CTX in future studies applied to anticancer therapy.


Asunto(s)
Anticuerpos Monoclonales , Nanopartículas , Cetuximab , Cromatografía Líquida de Alta Presión , Ácidos Cumáricos , Límite de Detección
20.
Rev Gaucha Enferm ; 41(spe): e20190146, 2020.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-31800800

RESUMEN

OBJECTIVE: To evaluate the knowledge of patients with venous ulcers (VU) on their chronic disease, treatment, and prevention of complications, according to the Nursing Outcomes Classification-NOC. METHODS: This is a cross-sectional study conducted between 2017 and 2018 in a Brazilian hospital. The sample consisted of 38 patients with VU attended in outpatient nursing consultations. The study analyzed sociodemographic, clinical and nine indexes from the Knowledge: Chronic Disease Management (1847) of the NOC, assessed using a five-point Likert scale, analyzed using descriptive statistics. RESULTS: The mean of the result Knowledge: Chronic Disease Management (1847) was 3.56±1.42. The clinical index Procedures involved in treatment regimen had the highest mean 4.18±0.21, followed by Pain management strategies with 3.92±0.27. In the association between knowledge and healing, the best scores were in patients with at least one healed VU. CONCLUSION: The knowledge of the patients was moderate and it was necessary to promote educational actions according to individual demands.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Terminología Normalizada de Enfermería , Úlcera Varicosa/terapia , Anciano , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA