Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 91
Filtrar
1.
Hum Genet ; 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38642129

RESUMO

Copper is a vital micronutrient involved in many biological processes and is an essential component of tumour cell growth and migration. Copper influences tumour growth through a process called cuproplasia, defined as abnormal copper-dependent cell-growth and proliferation. Copper-chelation therapy targeting this process has demonstrated efficacy in several clinical trials against cancer. While the molecular pathways associated with cuproplasia are partially known, genetic heterogeneity across different cancer types has limited the understanding of how cuproplasia impacts patient survival. Utilising RNA-sequencing data from The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) datasets, we generated gene regulatory networks to identify the critical cuproplasia-related genes across 23 different cancer types. From this, we identified a novel 8-gene cuproplasia-related gene signature associated with pan-cancer survival, and a 6-gene prognostic risk score model in low grade glioma. These findings highlight the use of gene regulatory networks to identify cuproplasia-related gene signatures that could be used to generate risk score models. This can potentially identify patients who could benefit from copper-chelation therapy and identifies novel targeted therapeutic strategies.

2.
Molecules ; 28(15)2023 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-37570862

RESUMO

The conjugation of polyphenols is a valuable strategy with which to confer tailored properties to polymeric materials of biomedical interest. Within this investigation, we aim to explore the possibility to use this synthetic approach to increase the viscosity of conjugates, thus allowing the release of a loaded therapeutic to be better controlled over time than in neat polyphenols. Curcumin (CUR) was conjugated to sodium alginate (CA) and chitosan (CS) with functionalisation degrees of 9.2 (SA-CUR) and 15.4 (CS-CUR) mg g-1. Calorimetric analyses showed higher degrees of chain rigidity upon conjugation, with a shift of the degradation peaks to higher temperatures (from 239 to 245 °C and from 296 to 303 °C for SA-CUR and CS-CUR, respectively). Rheological analyses were used to prove the enhanced interconnection between the polymer chains in the conjugates, confirmed by the weak gel parameters, A and z. Moreover, the typical non-Newtonian behaviour of the high-molecular-weight polysaccharides was recorded, together with an enhancement of the activation energy, Ea, in CS-CUR vs. CS (opposite behaviour recorded for SA-CUR vs. SA). The evaluation of the delivery performance (of Doxorubicin as a model drug) showed sustained release profiles, opening opportunities for the development of controlled delivery systems.


Assuntos
Quitosana , Curcumina , Nanopartículas , Curcumina/química , Quitosana/química , Alginatos/química , Sistemas de Liberação de Medicamentos , Polímeros , Nanopartículas/química , Portadores de Fármacos/química , Liberação Controlada de Fármacos
3.
Int J Mol Sci ; 23(4)2022 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-35216501

RESUMO

In this study, actively-targeted (CD44-receptors) and dual stimuli (pH/redox)-responsive lipid-polymer nanoparticles were proposed as a delivery vehicle of doxorubicin hydrochloride in triple negative breast cancer cell lines. A phosphatidylcholine lipid film was hydrated with a solution of oxidized hyaluronic acid and doxorubicin, chosen as model drug, followed by a crosslinking reaction with cystamine hydrochloride. The obtained spherical nanoparticles (mean diameter of 30 nm) were found to be efficiently internalized in cancer cells by a receptor-mediated endocytosis process, and to modulate the drug release depending on the pH and redox potential of the surrounding medium. In vitro cytotoxicity assays demonstrated the safety and efficacy of the nanoparticles in enhancing the cytotoxic effect of the free anticancer drug, with the IC50 values being reduced by two and three times in MDA-MB-468 and MDA-MB-231, respectively. The combination of self-assembled phospholipid molecules with a polysaccharide counterpart acting as receptor ligand, and stimuli-responsive chemical moieties, was carried out on smart multifunctional nanoparticles able to actively target breast cancer cells and improve the in vitro anticancer activity of doxorubicin.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Doxorrubicina/química , Doxorrubicina/farmacologia , Lipídeos/química , Lipossomos/química , Nanopartículas/química , Polissacarídeos/química , Antineoplásicos/farmacologia , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos/efeitos dos fármacos , Endocitose/efeitos dos fármacos , Feminino , Humanos , Receptores de Hialuronatos/metabolismo , Ácido Hialurônico/metabolismo , Concentração de Íons de Hidrogênio , Tamanho da Partícula
4.
Molecules ; 27(13)2022 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-35807300

RESUMO

Water decontamination is an important challenge resulting from the incorrect disposal of heavy metal waste into the environment. Among the different available techniques (e.g., filtration, coagulation, precipitation, and ion-exchange), adsorption is considered the cheapest and most effective procedure for the removal of water pollutants. In the last years, several materials have been tested for the removal of heavy metals from water, including metal-organic frameworks (MOFs), single-walled carbon nanotubes (SWCNTs), and graphene oxide (GO). Nevertheless, their powder consistency, which makes the recovery and reuse after adsorption difficult, is the main drawback for these materials. More recently, SWCNT buckypapers (SWCNT BPs) have been proposed as self-standing porous membranes for filtration and adsorption processes. In this paper, the adsorption capacity and selectivity of Pb2+ (both from neat solutions and in the presence of other interferents) by SWCNT BPs were evaluated as a function of the increasing amount of GO used in their preparation (GO-SWCNT buckypapers). The highest adsorption capacity, 479 ± 25 mg g-1, achieved for GO-SWCNT buckypapers with 75 wt.% of graphene oxide confirmed the effective application of such materials for cheap and fast water decontamination from lead.


Assuntos
Grafite , Metais Pesados , Nanotubos de Carbono , Poluentes Químicos da Água , Adsorção , Descontaminação , Tecnologia , Água , Poluentes Químicos da Água/análise
5.
Molecules ; 27(22)2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36431774

RESUMO

Pharmaceutical products such as antibiotics, analgesics, steroids, and non-steroidal anti-inflammatory drugs (NSAIDs) are new emerging pollutants, often present in wastewater, potentially able to contaminate drinking water resources. Adsorption is considered the cheapest and most effective technique for the removal of pollutants from water, and, recently, membranes obtained by wet filtration method of SWCNT aqueous solutions (SWCNT buckypapers, SWCNT BPs) have been proposed as self-standing porous adsorbents. In this paper, the ability of graphene oxide/single-walled carbon nanotube composite membranes (GO-SWCNT BPs) to remove some important NSAIDs, namely Diclofenac, Ketoprofen, and Naproxen, was investigated at different pH conditions (pH 4, 6, and 8), graphene oxide amount (0, 20, 40, 60, and 75 wt.%), and initial NSAIDs concentration (1, 10, and 50 ppm). For the same experimental conditions, the adsorption capacities were found to strongly depend on the graphene oxide content. The best results were obtained for 75 wt.% graphene oxide with an adsorption capacity of 118 ± 2 mg g-1 for Diclofenac, 116 ± 2 mg g-1 for Ketoprofen, and 126 ± 3 mg g-1 for Naproxen at pH 4. Overall, the reported data suggest that GO-SWCNT BPs can represent a promising tool for a cheap and fast removal of NSAIDs from drinking water resources, with easy recovery and reusability features.


Assuntos
Água Potável , Poluentes Ambientais , Cetoprofeno , Diclofenaco/química , Cetoprofeno/química , Naproxeno/química , Anti-Inflamatórios não Esteroides/química
6.
Int J Mol Sci ; 22(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209825

RESUMO

Functional nanocarriers which are able to simultaneously vectorize drugs to the site of interest and exert their own cytotoxic activity represent a significant breakthrough in the search for effective anticancer strategies with fewer side effects than conventional chemotherapeutics. Here, we propose previously developed, self-assembling dextran-curcumin nanoparticles for the treatment of prostate cancer in combination therapy with Doxorubicin (DOXO). Biological effectiveness was investigated by evaluating the cell viability in either cancer and normal cells, reactive oxygen species (ROS) production, apoptotic effect, interference with the cell cycle, and the ability to inhibit cell migration and reverse the epithelial to mesenchymal transition (EMT). The results proved a significant enhancement of curcumin efficiency upon immobilization in nanoparticles: IC50 reduced by a half, induction of apoptotic effect, and improved ROS production (from 67 to 134%) at low concentrations. Nanoparticles guaranteed a pH-dependent DOXO release, with a more efficient release in acidic environments. Finally, a synergistic effect between nanoparticles and Doxorubicin was demonstrated, with the free curcumin showing additive activity. Although in vivo studies are required to support the findings of this study, these preliminary in vitro data can be considered a proof of principle for the design of an effective therapy for prostate cancer treatment.


Assuntos
Curcumina/farmacologia , Dextranos/farmacologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Neoplasias da Próstata/patologia , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Curcumina/administração & dosagem , Dextranos/administração & dosagem , Doxorrubicina/administração & dosagem , Doxorrubicina/farmacologia , Sistemas de Liberação de Medicamentos , Humanos , Masculino , Nanopartículas , Células PC-3
7.
Molecules ; 26(5)2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33802608

RESUMO

In this work, we combined electrically-conductive graphene oxide and a sodium alginate-caffeic acid conjugate, acting as a functional element, in an acrylate hydrogel network to obtain multifunctional materials designed to perform multiple tasks in biomedical research. The hybrid material was found to be well tolerated by human fibroblast lung cells (MRC-5) (viability higher than 94%) and able to modify its swelling properties upon application of an external electric field. Release experiments performed using lysozyme as the model drug, showed a pH and electro-responsive behavior, with higher release amounts and rated in physiological vs. acidic pH. Finally, the retainment of the antioxidant properties of caffeic acid upon conjugation and polymerization processes (Trolox equivalent antioxidant capacity values of 1.77 and 1.48, respectively) was used to quench the effect of hydrogen peroxide in a hydrogel-assisted lysozyme crystallization procedure.


Assuntos
Alginatos/química , Antioxidantes/farmacologia , Ácidos Cafeicos/farmacologia , Citotoxinas/farmacologia , Grafite/química , Hidrogéis/química , Estresse Oxidativo/efeitos dos fármacos , Antioxidantes/química , Ácidos Cafeicos/química , Células Cultivadas , Citotoxinas/química , Liberação Controlada de Fármacos , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Humanos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Polimerização
8.
Molecules ; 26(22)2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34834096

RESUMO

The performance of Carbon Nanotubes hybrid hydrogels for environmental remediation was investigated using Methylene Blue (MB), Rhodamine B (RD), and Bengal Rose (BR) as model contaminating dyes. An acrylate hydrogel network with incorporated CNT was synthesized by photo-polymerization without any preliminary derivatization of CNT surface. Thermodynamics, isothermal and kinetic studies showed favorable sorption processes with the application of an external 12 V electric field found to be able to influence the amount of adsorbed dyes: stronger interactions with cationic MB molecules (qexp and qexp12 of 19.72 and 33.45 mg g-1, respectively) and reduced affinity for anionic RD (qexp and qexp12 of 28.93 and 13.06 mg g-1, respectively) and neutral BR (qexp and qexp12 of 36.75 and 15.85 mg g-1, respectively) molecules were recorded. The influence of pH variation on dyes adsorption was finally highlighted by reusability studies, with the negligible variation of adsorption capacity after five repeated sorption cycles claiming for the suitability of the proposed systems as effective sorbent for wastewater treatment.

9.
Pharm Res ; 37(3): 55, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32060727

RESUMO

PURPOSE: Solid tumors exhibit an altered redox state in comparison with normal tissues due to tumor hypoxia, lower pH, and elevated levels of the tripeptide glutathione. This study describes the preparation of functional redox-responsive nanoparticles proposed as delivery vehicle of Doxorubicin in adrenocortical cancer in vitro. METHODS: Curcumin and Lipoic acid were conjugated to Human Serum Albumin and nanoparticle systems were prepared via a modified desolvation method. Scanning electron microscopy, Fourier transmission IR, dynamic light scattering and differential scanning calorimetry analyses were used to characterize the nanoparticles. Balb3T3 and H295R were used as in vitro models of health and cancer cells, respectively. RESULTS: Nanoparticles with a spherical shape and a mean diameter of 70 nm were observed, increasing up to ten-folds upon exposure to glutathione 10 mM. Redox responsive Doxorubicin release was recorded, with loaded nanoparticles significantly enhancing the drug cytotoxicity against H295R adrenocortical tumor cells. Cell uptake experiments revealed a rapid and efficient internalization of the nanoparticles. CONCLUSIONS: A valuable tools to actively improve the in vitro anticancer activity of Doxorubicin against adrenocortical cancer was proposed. The effectiveness of the delivery vehicle is related to the presence of both Lipoic acid and Curcumin moieties, enhancing the glutathione responsivity, and the drug cytotoxicity, respectively.


Assuntos
Carcinoma Adrenocortical/tratamento farmacológico , Albuminas/química , Doxorrubicina/administração & dosagem , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Curcumina , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Liberação Controlada de Fármacos , Humanos , Camundongos , Tamanho da Partícula , Ácido Tióctico
10.
J Phys Chem A ; 124(46): 9513-9523, 2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33170012

RESUMO

This work demonstrates how push-pull substitution can induce spectral tuning toward the visible range and improve the photoisomerization efficiency of azobenzene-based photoswitches, making them good candidates for technological and biological applications. The red-shifted bright ππ* state (S2) behaves like the lower and more productive dark nπ* (S1) state because less potential energy along the planar bending mode is available to reach higher energy unproductive nπ*/S0 crossing regions, which are responsible for the lower quantum yield of the parent compound. The stabilization of the bright ππ* state and the consequent increase in isomerization efficiency may be regulated via the strength of push-pull substituents. Finally, the torsional mechanism is recognized here as the unique productive route because structures with bending values attributable to the inversion mechanism were never detected, out of the 280 ππ* time-dependent density functional theory (RASPT2-validated) dynamics simulations.

11.
Molecules ; 25(24)2020 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-33419366

RESUMO

The "Materials Chemistry" Section of Molecules is an open access place for the dissemination of theoretical and experimental studies related to the chemical approaches to materials-based problems [...].


Assuntos
Materiais Biocompatíveis/química , Hidrogéis/química , Ciência dos Materiais/normas , Nanopartículas/química , Energia Renovável/normas , Humanos , Hidrogéis/uso terapêutico , Nanopartículas/uso terapêutico
12.
Molecules ; 25(9)2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32365886

RESUMO

Carbon nanostructures (CN) are emerging valuable materials for the assembly of highly engineered multifunctional nanovehicles for cancer therapy, in particular for counteracting the insurgence of multi-drug resistance (MDR). In this regard, carbon nanotubes (CNT), graphene oxide (GO), and fullerenes (F) have been proposed as promising materials due to their superior physical, chemical, and biological features. The possibility to easily modify their surface, conferring tailored properties, allows different CN derivatives to be synthesized. Although many studies have explored this topic, a comprehensive review evaluating the beneficial use of functionalized CNT vs G or F is still missing. Within this paper, the most relevant examples of CN-based nanosystems proposed for MDR reversal are reviewed, taking into consideration the functionalization routes, as well as the biological mechanisms involved and the possible toxicity concerns. The main aim is to understand which functional CN represents the most promising strategy to be further investigated for overcoming MDR in cancer.


Assuntos
Antineoplásicos/química , Carbono/química , Resistencia a Medicamentos Antineoplásicos , Nanoestruturas/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Resistência a Múltiplos Medicamentos , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia
13.
Crit Rev Food Sci Nutr ; 56(2): 326-37, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-24867371

RESUMO

In recent years, antioxidants have gained great importance because of their potential use in food, pharmaceutical, and cosmetic industries. This interest is rooted in the cumulative evidence connecting active oxygen and free radicals with numerous human degenerative disorders, such as cardiovascular diseases, cancer, aging, and atherosclerosis. Polyphenols are the major class of antioxidant able to reduce the oxidative damages of lipids, proteins, enzymes, carbohydrates, and DNA in living cells and tissues. Among the realm of polyphenol compounds, polyphenol conjugates have been proposed as innovative materials which, by combining the advantageous properties of both the components, can increase the efficiency of antioxidants and their range of application in nutritional and biomedical fields. This work is an overview of the different class of polyphenol conjugates, which will be analyzed in terms of nutritional and biological properties, showing how these bio-conjugates will positively affect the human health.


Assuntos
Antioxidantes/química , Plantas/química , Polifenóis/química , Análise de Alimentos , Humanos , Polifenóis/farmacologia
14.
Int J Cancer ; 137(10): 2492-503, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26059723

RESUMO

Many tumors including prostate cancer are maintained by cancer stem cells (CSCs), which might cause tumor relapse if not eradicated during the course of treatment. Specific targeting or radiosensitization of CSCs bear promise to improve tumor curability by synergistic effects in combination with radiotherapy. Carbon nanotubes (CNTs) can be used as promising drug delivery systems for anticancer drugs such as the flavonoid catechin. Catechin is an extensively studied active ingredient of the different plants, including green tea, and it is widely recognized as co-adjuvant in cancer therapy. Here we describe the synthesis of biocompatible, catechin-loaded and gelatin-conjugated CNTs (Gel_CT_CNTs) with anticancer properties and demonstrate their potential for the eradication of prostate CSCs in combination with X-ray irradiation. Gel_CT_CNTs showed a significant enhancement of in vitro anticancer activity as compared to catechin alone. Moreover, treatment of prostate cancer cells with Gel_CT_CNT nanohybrids inhibited the tumorigenic cell population defined by a high aldehyde dehydrogenase (ALDH) activity. A combination of X-ray irradiation and treatment with Gel_CT_CNTs caused a decrease in the protein level of stem cell-related transcription factors and regulators including Nanog, Oct4 and ß-catenin and led to an increase of cancer cell radiosensitivity as demonstrated by clonogenic and spherogenic cell survival assays. Taken together, our results suggest that a combination of irradiation and Gel_CT_CNTs can be potentially used for the radiosensitization and eradication of prostate CSC populations.


Assuntos
Antineoplásicos/síntese química , Catequina/química , Gelatina/química , Nanotubos de Carbono/química , Neoplasias da Próstata/terapia , Radiossensibilizantes/síntese química , Aldeído Desidrogenase/metabolismo , Animais , Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Proliferação de Células , Quimiorradioterapia/métodos , Composição de Medicamentos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Transplante de Neoplasias , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/efeitos da radiação , Neoplasias da Próstata/patologia , Radiossensibilizantes/administração & dosagem
15.
Pharm Res ; 32(6): 2132-43, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25537340

RESUMO

PURPOSE: Preparation of Nanographene oxide (NGO) - Gelatin hybrids for efficient treatment of Neuroblastoma. METHODS: Nanohybrids were prepared via non-covalent interactions. Spectroscopic tools have been used to discriminate the chemical states of NGO prior and after gelatin coating, with UV visible spectroscopy revealing the maximum binding capacity of gelatin to NGO. Raman and X-ray photoelectron spectroscopy (XPS) demonstrated NGO and Gelatin_NGO nanohybrids through a new chemical environments produced after noncovalent interaction. Microscopic analyses, atomic force microscopy (AFM) and scanning electron microscopy (SEM) are used to estimate the thickness of samples and the lateral width in the nanoscale, respectively. RESULTS: The cell viability assay validated Gelatin_NGO nanohybrids as a useful nanocarrier for Carboplatin (CP) release and delivery, without obvious signs of toxicity. The nano-sized NGO (200 nm and 300 nm) did not enable CP to kill the cancer cells efficiently, whilst the CP loaded Gel_NGO 100 nm resulted in a synergistic activity through increasing the local concentration of CP inside the cancer cells. CONCLUSIONS: The nanohybrids provoked high stability and dispersibility in physiological media, as well as enhanced the anticancer activity of the chemotherapy agent Carboplatin (CP) in human neuroblastoma cells.


Assuntos
Antineoplásicos/farmacologia , Carboplatina/farmacologia , Portadores de Fármacos , Gelatina/química , Grafite/química , Nanopartículas , Neuroblastoma/tratamento farmacológico , Óxidos/química , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Antineoplásicos/metabolismo , Carboplatina/administração & dosagem , Carboplatina/química , Carboplatina/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Química Farmacêutica , Relação Dose-Resposta a Droga , Humanos , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Nanomedicina , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Espectroscopia Fotoeletrônica , Espectrofotometria Ultravioleta , Análise Espectral Raman , Tecnologia Farmacêutica/métodos
16.
Drug Dev Ind Pharm ; 41(12): 2006-17, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26023992

RESUMO

Biodegradable casein nanospheres for the sustained release of bioactive molecules in the gastro-intestinal tract were prepared by precipitation polymerization using sodium methacrylate (NaMA) and N,N'-methylene bis-acrylamide (MEBA) as pH-responsive monomer and cross-linker. Three materials with different casein amount were obtained and characterized by scanning electron microscopy, dimensional analysis, water uptake, cytotoxicity and enzymatic degradation experiments. Nanospheres biodegradability was tuned by coating with polyacrylic acid. Coated and uncoated materials were investigated as delivery vehicles for diclofenac sodium salt. For un-coated samples, the release raise 100% in 30 h, while for coated specimens these values were lower than 70%, due to the diffusional constraints of polymer layer.


Assuntos
Caseínas/administração & dosagem , Caseínas/química , Sistemas de Liberação de Medicamentos/métodos , Nanosferas/administração & dosagem , Nanosferas/química , Administração Oral , Caseínas/metabolismo , Linhagem Celular , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Nanosferas/metabolismo
17.
Pharm Dev Technol ; 20(3): 288-96, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-24289106

RESUMO

In this study, pH-responsive hydrogels, synthesized by the coupling reaction of polyacrylic acid and catechin, are proposed as carriers of oxidable drugs toward the GI tract. The presence of polyphenolic moieties in the network gives the polymers properties suitable for the release of unstable drugs in oxidative conditions. The characterization of the hydrogels is obtained by means of morphological and physico-chemical analyses, antioxidant assays and evaluation of the swelling behavior in media simulating the gastric (pH 1.0) and the intestinal (pH 7.4) tracts. The hydrogels are tested as pH-responsive carriers in in vitro release studies of folic acid and thiamine, two model drugs easily degraded by oxidative conditions simulated by UV irradiation and t-butyl hydroperoxide treatment, respectively. Results show that catechin-based carriers are able to control the release of drugs at different pH values, giving a remarkable improvement in the stability of the therapeutics.


Assuntos
Portadores de Fármacos/química , Flavonoides/química , Ácido Fólico/química , Tiamina/química , Resinas Acrílicas/química , Antioxidantes/administração & dosagem , Antioxidantes/química , Antioxidantes/farmacologia , Catequina/química , Química Farmacêutica/métodos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Ácido Fólico/administração & dosagem , Ácido Fólico/farmacologia , Hidrogéis , Concentração de Íons de Hidrogênio , Oxirredução , Polímeros/química , Tiamina/administração & dosagem , Tiamina/farmacologia
18.
J Mater Sci Mater Med ; 25(1): 67-77, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24105417

RESUMO

Different fluoroquinolon-type antibiotics were conjugated to gelatin with the aim to synthesize biomacromolecules with antimicrobial properties. The covalent linkage of the antibiotic was performed by a radical process involving the residues in the side chains of gelatin able to undergo oxidative modifications. The conjugation of antibiotic moieties onto the protein structure was confirmed by FT-IR, UV-Vis, fluorescence, and calorimetric analyses. Biocompatibility tests were performed on human bone marrow mesenchymal stromal cells and the antibacterial properties of bioactive polymers were investigated by appropriate tests against Klebsiella pneumoniae and Escherichia coli. With regard to the tests conducted in the presence of E. coli, a minimum inhibitory concentration (MIC) ranging from 0.05 to 0.40 µg mL(-1) was recorded, while in the presence of K. pneumoniae this concentration varies from 0.10 to 1.60 µg mL(-1). In all the conjugates, the drug moieties retain their biological activity and the MIC values are lower than the resistance parameters of fluoroquinolon-type antibiotics versus Enterobacteriacae. The collected data suggest a broad range of applications, from biomedical to pharmaceutical and food science for all conjugates.


Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Fluoroquinolonas/síntese química , Fluoroquinolonas/farmacologia , Antibacterianos/química , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Células Cultivadas , Escherichia coli/efeitos dos fármacos , Fluoroquinolonas/química , Gelatina/química , Células-Tronco Hematopoéticas/efeitos dos fármacos , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Teste de Materiais , Testes de Sensibilidade Microbiana , Estrutura Molecular
19.
Int J Pharm X ; 7: 100235, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38486882

RESUMO

In this study, we developed self-assembling nanoparticles (LCPs) able to trigger the release of Chlorambucil (Chl) and Doxorubicin (DOX) to MDA-MB-231 cells by exploiting the enzyme and redox signals. The DOX loaded LCPs was prepared by the self-assembly of two chondroitin sulphate (CS) derivatives, obtained by the covalent conjugation of Lipoic Acid (LA) and Chlorambucil (Chl) to the CS backbone. After the physic-chemical characterization of the conjugates by FT-IR, 1H NMR, and determination of the critical aggregation concentration, spherical nanoparticles with mean hydrodynamic diameter of 45 nm (P.D.I. 0.24) and Z-potential of - 44 mV were obtained by water addition/solvent evaporation method. In vitro experiments for the release of Chl and DOX were performed in healthy and cancer cells, using a cell culture media to maintain the physiological intracellular conditions (pH 7.4) (and concentration of esterase and GSH. The results allowed the selective release of the payloads to be detected: Chl release of 0 and 41% were obtained after 2 h incubation in normal and in cancer cells respectively, while values of 35 (in healthy cells) and 60% (in cancer cells) were recorded for DOX release after 96 h. Finally, viability studies proved the ability of the newly proposed nanosystem to enhance the cytotoxic activity of the two drugs against cancer cells.

20.
Pharm Dev Technol ; 18(5): 1058-65, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22524466

RESUMO

CONTEXT: Flavonoids preservation and release. OBJECTIVE: Synthesis of a polymeric material able to prevent thermal and photo degradation of a flavonoid model compound, such as (+)-catechin, and suitable for a controlled/sustained delivery of this molecule in gastro-intestinal simulating fluids. MATERIALS AND METHODS: Methacrylic acid (MAA) was grafted onto poly(N-vinyl-pyrrolidone) (PVP) by a free radical grafting procedure involving a single-step reaction at room temperature. For this purpose, hydrogen peroxide/ascorbic acid redox pair was employed as water-soluble and biocompatible initiator system. RESULTS AND DISCUSSION: FT-IR spectra confirmed the insertion of MAA onto the polymeric chain. Stability studies, performed under various conditions, such as freeze-thaw cycles, exposure to strong light, thermal stability studies under constant humidity and with light protection at different temperatures, showed the preservative properties of the polymeric material towards flavonoids. Furthermore, the biocompatibility was highlighted by Hen's Egg Test-Chorioallantoic Membrane assay and in vitro release studies demonstrated the possibility to employ PVP-MAA copolymer as a device for gastro-intestinal release of flavonoids. CONCLUSION: The coupling of good preservative properties together with biocompatibility and the usefulness as carrier in controlled release make this kind of material very interesting from an industrial point of view for different applications in food, pharmaceutical, and cosmetic fields.


Assuntos
Flavonoides/química , Metacrilatos/química , Ácidos Polimetacrílicos/química , Polivinil/química , Pirrolidinas/química , Pirrolidinonas/química , Animais , Ácido Ascórbico/química , Materiais Biocompatíveis/química , Embrião de Galinha , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Peróxido de Hidrogênio/química , Ácidos Polimetacrílicos/síntese química , Água/química
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa