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1.
Polymers (Basel) ; 16(15)2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39125129

RESUMEN

Aqueous solutions of a thermoresponsive diblock copolymer poly(di-[ethylene glycol] methyl ether methacrylate)-b-poly(2-[diisopropylamino] ethyl methacrylate) (PDEGMA-b-PDIPAEMA) were studied by static, dynamic and electrophoretic light scattering, small-angle X-ray scattering and differential scanning calorimetry. Thermoresponsive behavior of PDEGMA-b-PDIPAEMA was investigated at two pH values, pH = 2, at which the terminal carboxylic group of the PDEGMA chain and the PDIPAEMA block are protonated, and pH = 7, where the carboxyl terminal group is ionized while the PDIPAEMA block is partially deprotonated and more hydrophobic. Both at pH = 2 and 7, PDEGMA-b-PDIPAEMA copolymer underwent extensive association (the size of the aggregates was between 100 and 300 nm), indicating strong interchain interactions. While the measurements confirmed thermoresponsive behavior of PDEGMA-b-PDIPAEMA at pH = 7, no changes in the association with temperature were observed at pH 2 as the thermoresponsivity of PDEGMA was suppressed by hydrogen bonding between carboxylic groups and PDEGMA segments, as well as due to the increased hydrophilicity of the PDIPAEMA block. Fluorescence measurements with pyrene as a fluorescent probe showed that both at pH = 2 and pH = 7 the associates were able to solubilize hydrophobic substances.

2.
Acta Biomater ; 154: 83-96, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36162763

RESUMEN

The gastrointestinal (GI) tract, particularly the colon region, holds a highly diverse microbial community that plays an important role in the metabolism, physiology, nutrition, and immune function of the host body. Accumulating evidence has revealed that alteration in these microbial communities is the pivotal step in developing various metabolic diseases, including obesity, inflammatory bowel disease (IBD), and colorectal cancer. However, there is still a lack of clear understanding of the interrelationship between microbiota and diet as well as the effectiveness of chemoprevention strategies, including pre and probiotic agents in modifying the colonic microbiota and preventing digestive diseases. Existing methods for assessing these microbiota-diet interactions are often based on samples collected from the feces or endoscopy techniques which are incapable of providing information on spatial variations of the gut microbiota or are considered invasive procedures. To address this need, here we have developed an electronic-free smart capsule that enables site-specific sampling of the gut microbiome within the proximal colon region of the GI tract. The 3D printed device houses a superabsorbent hydrogel bonded onto a flexible polydimethylsiloxane (PDMS) disk that serves as a milieu to collect the fluid in the gut lumen and its microbiome by rapid swelling and providing the necessary mechanical actuation to close the capsule after the sampling is completed. The targeted colonic sampling is achieved by coating the sampling aperture on the capsule with a double-layer pH-sensitive enteric coating, which delays fluid in the lumen from entering the capsule until it reaches the proximal colon of the GI tract. To identify the appropriate pH-responsive double-layer coating and processing condition, a series of systematic dissolution characterizations in different pH conditions that mimicked the GI tract was conducted. The effective targeted microbial sampling performance and preservation of the smart capsule with the optimized design were validated using both realistic in vitro GI tract models with mixed bacteria cultures and in vivo with pigs as an animal model. The results from 16s rRNA and WideSeq analysis in both in vitro and in vivo studies showed that the bacterial population sampled within the retrieved capsule closely matched the bacterial population within the targeted sampling region (proximal colon). Herein, it is envisioned that such smart sampling capsule technology will provide new avenues for gastroenterological research and clinical applications, including diet-host-microbiome relationships, focused on human GI function and health. STATEMENT OF SIGNIFICANCE: The colonic microbiota plays a major role in the etiology of numerous diseases. Extensive efforts have been conducted to monitor the gut microbiome using sequencing technologies based on samples collected from feces or mucosal biopsies that are typically obtained by colonoscopy. Despite the simplicity of fecal sampling procedures, they are incapable of preserving spatial and temporal information about the bacteria through the gastrointestinal (GI) tract. In contrast, colonoscopy is an invasive and impractical approach to frequently assess the effect of dietary and therapeutic intake on the microbiome and their impact on the health of the patient. Here, we developed a non-invasive capsule that enables targeted sampling from the ascending colon, thereby providing crucial information for disease prediction and monitoring.


Asunto(s)
Microbioma Gastrointestinal , Microbiota , Humanos , Porcinos , Animales , ARN Ribosómico 16S/genética , Microbioma Gastrointestinal/fisiología , Colon , Heces/microbiología , Bacterias
3.
Macromol Rapid Commun ; 43(24): e2200420, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35820157

RESUMEN

Poly 2-vinyl-4,4-dimethylazlactone (PVDMA) has received much attention as a "reactive platform" to prepare charge-shifting polycations via post-polymerization modification with tertiary amines that possess primary amine or hydroxyl reactive handles. Upon hydrolysis of the resulting amide or ester linkages, the polymers can undergo a gradual transition in net charge from cationic to anionic. Herein, a systematic investigation of the hydrolysis rate of PVDMA-derived charge-shifting polymers is described. PVDMA is modified with tertiary amines bearing either primary amine, hydroxyl, or thiol reactive handles. The resulting polymers possess tertiary amine side chains connected to the backbone via amide, ester, or thioester linkages. The hydrolysis rates of each PVDMA derivative are monitored at 25 and 50 °C at pH values of 5.5, 7.5, and 8.5, respectively. While the hydrolysis rate of the amide-functionalized PVDMA is negligible over the period investigated, the hydrolysis rates of the ester- and thioester-functionalized PVDMA increase with increasing temperature and pH. Interestingly, the hydrolysis rate of the thioester-functionalized PVDMA appears to be more rapid than the ester-functionalized PVDMA at all pH values and temperatures investigated. It is believed that these results can be utilized to inform the future preparation of PVDMA-based charge-shifting polymers for biomedical applications.


Asunto(s)
Aminas , Polímeros , Polímeros/química , Hidrólisis , Aminas/química , Temperatura
4.
Molecules ; 27(13)2022 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-35807477

RESUMEN

Thermo-responsive hydrophilic polymers, including those showing tuneable lower critical solution temperature (LCST), represent a continuous subject of exploration for a variety of applications, but particularly in nanomedicine. Since biological pH changes can inform the organism about the presence of disequilibrium or diseases, the development of dual LCST/pH-responsive hydrophilic polymers with biological potential is an attractive subject in polymer science. Here, we present a novel polymer featuring LCST/pH double responsiveness. The monomer ethylthiomorpholine oxide methacrylate (THOXMA) can be polymerised via the RAFT process to obtain well-defined polymers. Copolymers with hydroxyethyl methacrylate (HEMA) were prepared, which allowed the tuning of the LCST behaviour of the polymers. Both, the LCST behaviour and pH responsiveness of hydrophilic PTHOXMA were tested by following the evolution of particle size by dynamic light scattering (DLS). In weak and strong alkaline conditions, cloud points ranged between 40-60 °C, while in acidic medium no LCST was found due to the protonation of the amine of the THOX moieties. Additional cytotoxicity assays confirmed a high biocompatibility of PTHOXMA and haemolysis and aggregation assays proved that the thiomorpholine oxide-derived polymers did not cause aggregation or lysis of red blood cells. These preliminary results bode well for the use of PTHOXMA as smart material in biological applications.


Asunto(s)
Polímeros de Estímulo Receptivo , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Morfolinas , Óxidos , Polímeros/química , Polímeros/farmacología , Temperatura
5.
Polymers (Basel) ; 14(2)2022 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-35054689

RESUMEN

Thermo- and pH-responsive poly(N-[3-(diethylamino)propyl]methacrylamide)s were synthesized by free radical polymerization and RAFT polymerization. The molar masses of the samples were 33,000-35,000 g∙mol-1. Investigations of the dilute solutions showed that the prepared samples were flexible chain polymers. The behavior of the synthesized polymers in the buffer solutions was analyzed by turbidity and light scattering at a pH range of 7-13 and a concentration range of 0.0002-0.008 g·cm-3. When the concentrated solutions were at a low temperature, there were macromolecules and aggregates, which were formed due to the interaction of hydrophobic units. For the investigated samples, the lower critical solution temperatures were equal. The phase separation temperatures decreased as pH increased. The influence of polydispersity index on the characteristics of the samples in the solutions was analyzed. The radii of molecules of poly(N-[3-(diethylamino)propyl]methacrylamide) obtained by RAFT polymerization at this temperature at the onset and end of the phase separation interval were lower than ones for samples synthesized by conventional free radical polymerization.

6.
ACS Appl Mater Interfaces ; 13(30): 35233-35247, 2021 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-34283557

RESUMEN

Responsive polymers, which become protonated at decreasing pH, are considered a milestone in the development of synthetic cell entry vectors. Exact correlations between their properties and their ability to escape the endosome, however, often remain elusive due to hydrophobic interactions or limitations in the design of water-soluble materials with suitable basicity. Here, we present a series of well-defined, hydrophilic polypiperazines, where systematic variation of the amino moiety facilitates an unprecedented fine-tuning of the basicity or pKa value within the physiologically relevant range (pH 6-7.4). Coincubation of HEK 293T cells with various probes, including small fluorophores or functioning proteins, revealed a rapid increase of endosomal release for polymers with pKa values above 6.5 or 7 in serum-free or serum-containing media, respectively. Similarly, cytotoxic effects became severe at increased pKa values (>7). Although the window for effective transport appears narrow, the discovered correlations offer a principal guideline for the design of effective polymers for endosomal escape.


Asunto(s)
Resinas Acrílicas/farmacología , Endosomas/efectos de los fármacos , Proteínas Fluorescentes Verdes/metabolismo , Piperazinas/farmacología , Ribonucleasa Pancreática/metabolismo , Albúmina Sérica Bovina/metabolismo , Resinas Acrílicas/síntesis química , Resinas Acrílicas/toxicidad , Animales , Bovinos , Membrana Celular/efectos de los fármacos , Fluoresceínas/metabolismo , Células HEK293 , Hemólisis/efectos de los fármacos , Humanos , Concentración de Iones de Hidrógeno , Piperazinas/síntesis química , Piperazinas/toxicidad
7.
Pharmaceutics ; 13(5)2021 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-34068257

RESUMEN

Highly efficient pH-modulated cargo release was achieved with a new hybrid nanocarrier composed of a mesoporous silica core with functionalized pores and a grafted pH-responsive crosslinked polymer shell of 2-(diisopropylamino)ethyl methacrylate (pKa ≈ 6.5). The retention/release performance of the system was optimized by a novel approach using selective functionalization of the silica pores to tune the carrier-cargo interaction and by tunning the amount of grafted polymer. The system features excellent retention of cationic cargo at low pH and a burst release at higher pH. This results from the expanded-collapsed conformation transition of the pH-responsive polymer shell and the simultaneous change in the interaction between the cargo and the polymer shell and the modified pore walls. At low pH, the electrostatic interaction of the cationic cargo with the protonated amine groups of the extended polymer shell retains the cargo, resulting in very low leakage (OFF state). At high pH, the electrostatic interaction with the cargo is lost (due to deprotonation of the polymer amine groups), and the polymer shell collapses, squeezing out the cargo in a burst release (ON state). Pore functionalization in combination with the stimuli-responsive polymer shell is a very promising strategy to design high-performance ON:OFF smart hybrid nanocarriers for stimuli-actuated cargo release, with great potential for application in the controlled release of drugs and other biologically active agents.

8.
Front Bioeng Biotechnol ; 9: 632753, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33634089

RESUMEN

This review will focus on the controlled release of pharmaceuticals and other organic molecules utilizing polymeric nanolayers grown by initiated chemical vapor deposited (iCVD). The iCVD layers are able conform to the geometry of the underlying substrate, facilitating release from one- and two-dimensional nanostructures with high surface area. The reactors for iCVD film growth can be customized for specific substrate geometries and scaled to large overall dimensions. The absence of surface tension in vapor deposition processes allows the synthesis of pinhole-free layers, even for iCVD layers <10 nm thick. Such ultrathin layers also provide rapid transport of the drug across the polymeric layer. The mild conditions of the iCVD process avoid damage to the drug which is being encapsulated. Smart release is enabled by iCVD hydrogels which are responsive to pH, temperature, or light. Biodegradable iCVD layers have also be demonstrated for drug release.

9.
Mol Pharm ; 18(1): 87-100, 2021 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-33231464

RESUMEN

Pancreatic ductal adenocarcinoma (PDAC), a metabolic disorder, remains one of the leading cancer mortality sources worldwide. An initial response to treatments, such as gemcitabine (GEM), is often followed by emergent resistance reflecting an urgent need for alternate therapies. The PDAC resistance to GEM could be due to ERK1/2 activity. However, successful ERKi therapy is hindered due to low ligand efficiency, poor drug delivery, and toxicity. In this study, to overcome these limitations, we have designed pH-responsive nanoparticles (pHNPs) with a size range of 100-150 nm for the simultaneous delivery of ERKi (SCH 772984) and GEM with tolerable doses. These pHNPs are polyethylene glycol (PEG)-containing amphiphilic polycarbonate block copolymers with tertiary amine side chains. They are systemically stable and capable of improving in vitro and in vivo drug delivery at the cellular environment's acidic pH. The functional analysis indicates that the nanomolar doses of ERKi or GEM significantly decreased the 50% growth inhibition (IC50) of PDAC cells when encapsulated in pHNPs compared to free drugs. The combination of ERKi with GEM displayed a synergistic inhibitory effect. Unexpectedly, we uncover that the minimum effective dose of ERKi significantly promotes GEM activities on PDAC cells. Furthermore, we found that pHNP-encapsulated combination therapy of ERKi with GEM was superior to unencapsulated combination drug therapy. Our findings, thus, reveal a simple, yet efficient, drug delivery approach to overcome the limitations of ERKi for clinical applications and present a new model of sensitization of GEM by ERKi with no or minimal toxicity.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Desoxicitidina/análogos & derivados , Portadores de Fármacos/química , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Nanopartículas/química , Neoplasias Pancreáticas/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/administración & dosificación , Animales , Apoptosis/efectos de los fármacos , Carcinoma Ductal Pancreático/tratamiento farmacológico , Línea Celular Tumoral , Desoxicitidina/administración & dosificación , Desoxicitidina/química , Sistemas de Liberación de Medicamentos/métodos , Femenino , Humanos , Concentración de Iones de Hidrógeno , Masculino , Ratones , Ratones Desnudos , Polietilenglicoles/química , Polímeros/química , Inhibidores de Proteínas Quinasas/química , Ensayos Antitumor por Modelo de Xenoinjerto/métodos , Gemcitabina
10.
Adv Colloid Interface Sci ; 283: 102213, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32739324

RESUMEN

Double-hydrophilic block copolymers (DHBCs), consisting of at least two different water-soluble blocks, are an alternative to the classical amphiphilic block copolymers and have gained increasing attention in the field of biomedical applications. Although the chemical nature of the two blocks can be diverse, most classical DHBCs consist of a bioeliminable non-ionic block to promote solubilization in water, like poly(ethylene glycol), and a second block that is more generally a pH-responsive block capable of interacting with another ionic polymer or substrate. This second block is generally non-degradable and the presence of side chain functional groups raises the question of its fate and toxicity, which is a limitation in the frame of biomedical applications. In this review, following a first part dedicated to recent examples of non-degradable DHBCs, we focus on the DHBCs that combine a biocompatible and bioeliminable non-ionic block with a degradable functional block including polysaccharides, polypeptides, polyesters and other miscellaneous polymers. Their use to design efficient drug delivery systems for various biomedical applications through stimuli-dependent self-assembly is discussed along with the current challenges and future perspectives for this class of copolymers.


Asunto(s)
Materiales Biocompatibles/química , Interacciones Hidrofóbicas e Hidrofílicas , Polímeros/química , Animales , Humanos
11.
Materials (Basel) ; 13(15)2020 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-32727155

RESUMEN

Stimuli-responsive, "smart" polymeric materials used in the biomedical field function in a bio-mimicking manner by providing a non-linear response to triggers coming from a physiological microenvironment or other external source. They are built based on various chemical, physical, and biological tools that enable pH and/or temperature-stimulated changes in structural or physicochemical attributes, like shape, volume, solubility, supramolecular arrangement, and others. This review touches on some particular developments on the topic of stimuli-sensitive molecular tools for biomedical applications. Design and mechanistic details are provided concerning the smart synthetic instruments that are employed to prepare supra- and macro-molecular architectures with specific responses to external stimuli. Five major themes are approached: (i) temperature- and pH-responsive systems for controlled drug delivery; (ii) glycodynameric hydrogels for drug delivery; (iii) polymeric non-viral vectors for gene delivery; (iv) metallic nanoconjugates for biomedical applications; and, (v) smart organic tools for biomedical imaging.

12.
ACS Appl Mater Interfaces ; 12(16): 19062-19068, 2020 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-32255333

RESUMEN

Stretchable poly(N-isopropylacrylamide)-co-acrylic acid (pNIPAm-co-10% AAc) microgel-based reservoir devices were fabricated and used to control the release rate of the small molecule model drug tris(4-(dimethylamino)phenyl)methylium chloride (crystal violet, CV) to solution by varying the Au layer thickness coating the microgels and device elongation. Specifically, we showed that CV could be loaded into the microgel layer of the devices via electrostatic interactions at pH 6.5, and the release could be triggered upon exposure to a pH 3.0 solution, which breaks the microgel-CV electrostatic interactions. We demonstrated that the rate of release could be increased by decreasing the Au layer thickness coating microgels and by stretching, that is, thin Au and high elongation promoted the relatively fast release of CV from the device. We found that the Au overlayer thickness (and porosity) dominated the observed release rate profiles when the device was not stretched (or at low elongation), while elongation-induced cracks dominated the release rate at high elongation. We also showed that the CV release kinetics could transition from low ("off") to high ("on"), which enhanced when the devices are stretched. This behavior could be exploited in the future for autonomous release systems that release small molecules when stretched by natural processes, for example, movement of joints and muscles.


Asunto(s)
Resinas Acrílicas/química , Sistemas de Liberación de Medicamentos , Microgeles/química , Acrilatos/química , Materiales Biocompatibles/química , Violeta de Genciana/química , Violeta de Genciana/farmacocinética , Cinética , Modelos Químicos , Electricidad Estática
13.
Chemistry ; 26(59): 13352-13358, 2020 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-32330327

RESUMEN

The dual stimuli-controlled release of doxorubicin from gel-embedded nanoparticles is reported. Non-cytotoxic polymer nanoparticles are formed from poly(ethylene glycol)-b-poly(benzyl glutamate) that, uniquely, contain a central ester link. This connection renders the nanoparticles pH-responsive, enabling extensive doxorubicin release in acidic solutions (pH 6.5), but not in solutions of physiological pH (pH 7.4). Doxorubicin-loaded nanoparticles were found to be stable for at least 31 days and lethal against the three breast cancer cell lines tested. Furthermore, doxorubicin-loaded nanoparticles could be incorporated within a thermoresponsive poly(2-hydroxypropyl methacrylate) gel depot, which forms immediately upon injection of poly(2-hydroxypropyl methacrylate) in dimethyl sulfoxide solution into aqueous solution. The combination of the poly(2-hydroxypropyl methacrylate) gel and poly(ethylene glycol)-b-poly(benzyl glutamate) nanoparticles yields an injectable doxorubicin delivery system that facilities near-complete drug release when maintained at elevated temperatures (37 °C) in acidic solution (pH 6.5). In contrast, negligible payload release occurs when the material is stored at room temperature in non-acidic solution (pH 7.4). The system has great potential as a vehicle for the prolonged, site-specific release of chemotherapeutics.


Asunto(s)
Doxorrubicina , Nanopartículas , Polímeros/química , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Humanos , Concentración de Iones de Hidrógeno , Inyecciones
14.
Colloids Surf B Biointerfaces ; 191: 110988, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32276213

RESUMEN

Disruption of DNA carriers triggered by intracellular bio-stimulants has been broadly considered as most convenient strategy for efficient DNA delivery. In this direction, we have designed and synthesized pH, redox and ATP responsive cationic cross-linked polymers (CLPs) having disulfide and reversible boronic ester linkages. These CLPs also contain folate groups that are known for their targeting capability towards cancer cells. Biophysical studies showed that these cationic CLPs exhibited more effective DNA condensation in comparison to cationic linear polymers resulting in the formation of nano-sized polyplexes with sufficient positive zeta potentials and good colloidal stability at neutral pH (∼7.4). More interestingly, the polyplexes prepared from these CLPs have the ability to selectively release complexed DNA under conditions similar to those prevalent in cancer cells such as acidic pH, ATP rich surroundings or presence of glutathione, as revealed by ethidium bromide exclusion assay, agarose gel electrophoresis, AFM measurements, etc. Therefore, these cross-linked polymers have high potential of being effective non-viral gene delivery vehicles.


Asunto(s)
Boro/química , Cationes/química , Reactivos de Enlaces Cruzados/química , ADN/metabolismo , Disulfuros/química , Ésteres/química , Polímeros/química , ADN/química , Humanos
15.
Chemistry ; 26(25): 5611-5614, 2020 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-32065458

RESUMEN

Multiresponsive polymers that can respond to several external stimuli are promising materials for a manifold of applications. Herein, a facile method for the synthesis of triple-responsive (pH, temperature, CO2 ) poly(N,N-diethylaminoethyl methacrylamide) by a post-polymerization amidation of poly(methyl methacrylate) (PMMA) is presented. Combined with trivalent counterions ([Fe(CN)6 ]3- ) both an upper and lower critical solution temperature (UCST/LCST)-type phase behavior can be realized at pH 8 and 9. PMMA and PMMA-based block copolymers are readily accessible by living anionic and controlled radical polymerization techniques, which opens access to various responsive polymer architectures based on the developed functionalization method. This method can also be applied on melt-processed bulk PMMA samples to introduce functional, responsive moieties at the PMMA surface.

16.
ACS Appl Mater Interfaces ; 11(50): 47446-47455, 2019 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-31804062

RESUMEN

Poly(N-isopropylacrylamide)-co-acrylic acid microgel-based reservoir devices were constructed by "sandwiching" a single layer of microgels between two thin Au layers (all on a glass support). The microgels were loaded with the model drug crystal violet (CV) utilizing the electrostatic interactions between deprotonated acrylic acid (AAc) and the positively charged CV; release can be triggered from the microgels by neutralizing the deprotonated AAc groups at acidic conditions. Alkanethiols of different alkyl chain lengths and polarities were immobilized on the upper Au layer of the device, and the release rate of the model drug CV from the microgel layer, after acid neutralization, was assessed. We found that the CV release rate was the highest when the alkyl chain length was short and contained a hydrophilic moiety. Conversely, the release rate was hindered by the presence of thiols with long alkyl chain lengths and with no hydrophilic moiety. We explain this phenomenon by quantifying the thiol's ability to hinder acid penetration into the microgel layer, and the ability of free CV to pass through the upper Au layer and into the solution. Utilizing various thiols and mixed thiol layers, we are able to tune release profiles from these reservoir devices to potentially achieve array devices with precisely tuned small molecule release profiles.

17.
Artículo en Inglés | MEDLINE | ID: mdl-31828065

RESUMEN

Functional and stimuli-responsive nanofibers with an enhanced surface area/volume ratio provide controlled and triggered drug release with higher efficacy. In this study, chemotherapeutic agent Rose Bengal (RB) (4,5,6,7-tetrachloro-2', 4',5',7'-tetraiodofluoresceindisodium)-loaded water-soluble polyvinyl alcohol (PVA) nanofibers were synthesized by using the electrospinning method. A thin layer of poly(4-vinylpyridine-co-ethylene glycol dimethacrylate) p(4VP-co-EGDMA) was deposited on the RB-loaded nanofibers (PVA-RB) via initiated chemical vapor deposition (iCVD), coating the fiber surfaces to provide controllable solubility and pH response to the nanofibers. The uncoated and [p(4VP-co-EGDMA)-PVA] coated PVA-RB nanofiber mats were studied at different pH values to analyze their degradation and drug release profiles. The coated nanofibers demonstrated high stability at neutral and basic pH values for long incubation durations of 72 h, whereas the uncoated nanofibers dissolved in <2 h. The drug release studies showed that the RB release from coated PVA-RB nanofibers was higher at neutral and basic pH values, and proportional to the pH of the solution, whereas the degradation and RB release rates from the uncoated PVA-RB nanofibers were significantly higher and did not depend on the pH of environment. Further analysis of the release kinetics using the Peppas model showed that while polymer swelling and dissolution were the dominant mechanisms for the uncoated nanofibers, for the coated nanofibers, Fickian diffusion was the dominant release mechanism. The biocompatibility and therapeutic efficiency of the coated PVA-RB nanofibers against brain cancer was investigated on glioblastoma multiforme cancer cells (U87MG). The coated PVA nanofibers were observed to be highly biocompatible, and they significantly stimulated the ROS production in cells, increasing apoptosis. These promising results confirmed the therapeutic activity of the coated PVA-RB nanofibers on brain cancer cells, and encouraged their further evaluation as drug carrier structures in brain cancer treatment.

18.
Nanomedicine (Lond) ; 14(2): 215-223, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30511881

RESUMEN

Polymer nanoparticles offer significant benefits for improving delivery of biological therapeutics such as DNA and proteins, as they allow the cargo to be protected until it is delivered to a target cell. However, there are still challenges with achieving efficient delivery to the optimal cellular region. One significant roadblock is escape of nanoparticles from within the endosomal/lysosomal compartments into the cytosol. Here, we review the recent advances in understanding endosomal escape of polymer nanoparticles. We also discuss the current progress on investigating how nanoparticle structure can control endosomal escape. It is important to understand the fundamental biological processes that govern endosomal escape in order to design more effective therapeutic delivery systems.


Asunto(s)
Portadores de Fármacos/química , Endosomas/metabolismo , Nanopartículas/química , Polímeros/química , Animales , Transporte Biológico , Línea Celular , ADN/metabolismo , Portadores de Fármacos/metabolismo , Endosomas/ultraestructura , Humanos , Lisosomas/metabolismo , Lisosomas/ultraestructura , Nanopartículas/metabolismo , Proteínas/metabolismo
19.
Molecules ; 24(1)2018 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-30577475

RESUMEN

Cancer remains a leading cause of death worldwide with more than 10 million new cases every year. Tumor-targeted nanomedicines have shown substantial improvements of the therapeutic index of anticancer agents, addressing the deficiencies of conventional chemotherapy, and have had a tremendous growth over past several decades. Due to the pathophysiological characteristics that almost all tumor tissues have lower pH in comparison to normal healthy tissues, among various tumor-targeted nanomaterials, pH-responsive polymeric materials have been one of the most prevalent approaches for cancer diagnosis and treatment. In this review, we summarized the types of pH-responsive polymers, describing their chemical structures and pH-response mechanisms; we illustrated the structure-property relationships of pH-responsive polymers and introduced the approaches to regulating their pH-responsive behaviors; we also highlighted the most representative applications of pH-responsive polymers in cancer imaging and therapy. This review article aims to provide general guidelines for the rational design of more effective pH-responsive nanomaterials for cancer diagnosis and treatment.


Asunto(s)
Nanomedicina/métodos , Neoplasias/diagnóstico , Neoplasias/tratamiento farmacológico , Polímeros/química , Humanos , Concentración de Iones de Hidrógeno
20.
ACS Appl Mater Interfaces ; 10(51): 44354-44367, 2018 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-30525379

RESUMEN

Microfluidics technology is emerging as a promising strategy in improving the oral delivery of proteins and peptides. Herein, a multistage drug delivery system is proposed as a step forward in the development of noninvasive therapies. Undecylenic acid-modified thermally hydrocarbonized porous silicon (UnPSi) nanoparticles (NPs) were functionalized with the Fc fragment of immunoglobulin G for targeting purposes. Glucagon-like peptide-1 (GLP-1) was loaded into the NPs as a model antidiabetic drug. Fc-UnPSi NPs were coated with mucoadhesive chitosan and ultimately entrapped into a polymeric matrix with pH-responsive properties by microfluidic nanoprecipitation. The final formulation showed a controlled and narrow size distribution. The pH-responsive matrix remained intact in acidic conditions, dissolving only in intestinal pH, resulting in a sustained release of the payload. The NPs presented high cytocompatibility and increased levels of interaction with intestinal cells when functionalized with the Fc fragment, which was supported by the validation of the Fc-fragment integrity after conjugation to the NPs. Finally, the Fc-conjugated NPs showed augmented GLP-1 permeability in an intestinal in vitro model. These results highlight the potential of microfluidics as an advanced technique for the preparation of multistage platforms for oral administration. Moreover, this study provides new insights on the potential of the Fc receptor transcytotic capacity for the development of targeted therapies.


Asunto(s)
Quitosano , Antígenos de Histocompatibilidad Clase I/metabolismo , Hipoglucemiantes , Derivados de la Hipromelosa , Dispositivos Laboratorio en un Chip , Nanopartículas , Receptores Fc/metabolismo , Silicio , Administración Oral , Células CACO-2 , Quitosano/química , Quitosano/farmacocinética , Quitosano/farmacología , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/farmacocinética , Preparaciones de Acción Retardada/farmacología , Antígenos de Histocompatibilidad Clase I/química , Humanos , Hipoglucemiantes/química , Hipoglucemiantes/farmacocinética , Hipoglucemiantes/farmacología , Derivados de la Hipromelosa/química , Derivados de la Hipromelosa/farmacocinética , Derivados de la Hipromelosa/farmacología , Nanopartículas/química , Nanopartículas/uso terapéutico , Porosidad , Receptores Fc/química , Silicio/química , Silicio/farmacocinética , Silicio/farmacología
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