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1.
J Am Chem Soc ; 146(22): 14959-14971, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38781575

RESUMEN

Elicitation of effective antitumor immunity following cancer vaccination requires the selective activation of distinct effector cell populations and pathways. Here we report a therapeutic approach for generating potent T cell responses using a modular vaccination platform technology capable of inducing directed immune activation, termed the Protein-like Polymer (PLP). PLPs demonstrate increased proteolytic resistance, high uptake by antigen-presenting cells (APCs), and enhanced payload-specific T cell responses. Key design parameters, namely payload linkage chemistry, degree of polymerization, and side chain composition, were varied to optimize vaccine formulations. Linking antigens to the polymer backbone using an intracellularly cleaved disulfide bond copolymerized with a diluent amount of oligo(ethylene glycol) (OEG) resulted in the highest payload-specific potentiation of antigen immunogenicity, enhancing dendritic cell (DC) activation and antigen-specific T cell responses. Vaccination with PLPs carrying either gp100, E7, or adpgk peptides significantly increased the survival of mice inoculated with B16F10, TC-1, or MC38 tumors, respectively, without the need for adjuvants. B16F10-bearing mice immunized with gp100-carrying PLPs showed increased antitumor CD8+ T cell immunity, suppressed tumor growth, and treatment synergy when paired with two distinct stimulator of interferon gene (STING) agonists. In a human papillomavirus-associated TC-1 model, combination therapy with PLP and 2'3'-cGAMP resulted in 40% of mice completely eliminating implanted tumors while also displaying curative protection from rechallenge, consistent with conferment of lasting immunological memory. Finally, PLPs can be stored long-term in a lyophilized state and are highly tunable, underscoring the unique properties of the platform for use as generalizable cancer vaccines.


Asunto(s)
Vacunas contra el Cáncer , Polímeros , Linfocitos T , Animales , Ratones , Vacunas contra el Cáncer/inmunología , Vacunas contra el Cáncer/química , Polímeros/química , Polímeros/farmacología , Linfocitos T/inmunología , Linfocitos T/efectos de los fármacos , Ratones Endogámicos C57BL , Humanos , Línea Celular Tumoral
2.
ACS Cent Sci ; 8(10): 1435-1446, 2022 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-36313164

RESUMEN

Immune stimulating agents like Toll-like receptor 7 (TLR7) agonists induce potent antitumor immunity but are limited in their therapeutic window due to off-target immune activation. Here, we developed a polymeric delivery platform that binds excess unpaired cysteines on tumor cell surfaces and debris to adjuvant tumor neoantigens as an in situ vaccine. The metabolic and enzymatic dysregulation in the tumor microenvironment produces these exofacial free thiols, which can undergo efficient disulfide exchange with thiol-reactive pyridyl disulfide moieties upon intratumoral injection. These functional monomers are incorporated into a copolymer with pendant mannose groups and TLR7 agonists to target both antigen and adjuvant to antigen presenting cells. When tethered in the tumor, the polymeric glyco-adjuvant induces a robust antitumor response and prolongs survival of tumor-bearing mice, including in checkpoint-resistant B16F10 melanoma. The construct additionally reduces systemic toxicity associated with clinically relevant small molecule TLR7 agonists.

3.
Chem Sci ; 13(17): 4884-4892, 2022 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-35655864

RESUMEN

Fluorogenic nanoparticles (NPs) able to sense different physiological environments and respond with disaggregation and fluorescence switching OFF/ON are powerful tools in nanomedicine as they can combine diagnostics with therapeutic action. pH-responsive NPs are particularly interesting as they can differentiate cancer tissues from healthy ones, they can drive selective intracellular drug release and they can act as pH biosensors. Controlled polymerization techniques are the basis of such materials as they provide solid routes towards the synthesis of pH-responsive block copolymers that are able to assemble/disassemble following protonation/deprotonation. Ring opening metathesis polymerization (ROMP), in particular, has been recently exploited for the development of experimental nanomedicines owing to the efficient direct polymerization of both natural and synthetic functionalities. Here, we capitalize on these features and provide synthetic routes for the design of pH-responsive fluorogenic micelles via the assembly of ROMP block-copolymers. While detailed photophysical characterization validates the pH response, a proof of concept experiment in a model cancer cell line confirmed the activity of the biocompatible micelles in relevant biological environments, therefore pointing out the potential of this approach in the development of novel nano-theranostic agents.

4.
J Am Chem Soc ; 144(10): 4383-4392, 2022 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-35238544

RESUMEN

Herein, a synthetic polymer proteomimetic is described that reconstitutes the key structural elements and function of mussel adhesive protein. The proteomimetic was prepared via graft-through ring-opening metathesis polymerization of a norbornenyl-peptide monomer. The peptide was derived from the natural underwater glue produced by marine mussels that is composed of a highly repetitive 10 amino acid tandem repeat sequence. The hypothesis was that recapitulation of the repeating unit in this manner would provide a facile route to a nature-inspired adhesive. To this end, the material, in which the arrangement of peptide units was as side chains on a brush polymer rather than in a linear fashion as in the natural protein, was examined and compared to the native protein. Mechanical measurements of adhesion forces between solid surfaces revealed improved adhesion properties over the natural protein, making this strategy attractive for diverse applications. One such application is demonstrated, using the polymers as a surface adhesive for the immobilization of live cells.


Asunto(s)
Adhesivos , Bivalvos , Adhesivos/química , Animales , Bivalvos/química , Péptidos , Polimerizacion , Polímeros/química
5.
J R Soc Interface ; 18(180): 20210236, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34229457

RESUMEN

Seabirds have evolved numerous adaptations that allow them to thrive under hostile conditions. Many seabirds share similar colour patterns, often with dark wings, suggesting that their coloration might be adaptive. Interestingly, these darker wings become hotter when birds fly under high solar irradiance, and previous studies on aerofoils have provided evidence that aerofoil surface heating can affect the ratio between lift and drag, i.e. flight efficiency. However, whether this effect benefits birds remains unknown. Here, we first used phylogenetic analyses to show that strictly oceanic seabirds with a higher glide performance (optimized by reduced sink rates, i.e. the altitude lost over time) have evolved darker wings, potentially as an additional adaptation to improve flight. Using wind tunnel experiments, we then showed that radiative heating of bird wings indeed improves their flight efficiency. These results illustrate that seabirds may have evolved wing pigmentation in part through selection for flight performance under extreme ocean conditions. We suggest that other bird clades, particularly long-distance migrants, might also benefit from this effect and therefore might show similar evolutionary trajectories. These findings may also serve as a guide for bioinspired innovations in aerospace and aviation, especially in low-speed regimes.


Asunto(s)
Vuelo Animal , Alas de Animales , Animales , Fenómenos Biomecánicos , Aves , Filogenia , Temperatura
6.
Adv Mater ; 33(46): e2007504, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34145625

RESUMEN

Recent advances in polymer chemistry, materials sciences, and biotechnology have allowed the preclinical development of sophisticated programmable nanomedicines and materials that are able to precisely respond to specific disease-associated triggers and microenvironments. These stimuli, endogenous to the targeted diseases, include pH, redox-state, small molecules, and protein upregulation. Herein, recent advances and innovative approaches in programmable soft materials capable of sensing the aforementioned disease-associated stimuli and responding via a range of dynamic processes including morphological and size transitions, changes in mobility and retention, as well as disassembly are described. In this field generally, the majority of ongoing and past research effort has focused on oncology. Given this interest, examples of the latest innovative approaches to chemo- and immunotherapy treatment strategies for cancer are presented. Moreover, as the field broadens its attention, applications of programmable materials in other diseases are highlighted, with a special focus on cardiovascular disease and diabetes mellitus, where limited attention is paid by the field, but where many promising avenues exist with high potential impact.


Asunto(s)
Materiales Biocompatibles/química , Enfermedades Cardiovasculares/patología , Diabetes Mellitus/patología , Nanoestructuras/química , Neoplasias/patología , Antineoplásicos/química , Antineoplásicos/uso terapéutico , Enfermedades Cardiovasculares/metabolismo , Diabetes Mellitus/metabolismo , Portadores de Fármacos/química , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Polímeros/química , Microambiente Tumoral
7.
J Am Chem Soc ; 143(10): 4005-4016, 2021 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-33673734

RESUMEN

Melanin is a ubiquitous natural pigment found in a diverse array of organisms. Allomelanin is a class of nitrogen-free melanin often found in fungi. Herein, we find artificial allomelanin analogues exhibit high intrinsic microporosity and describe an approach for further increasing and tuning that porosity. Notably, the synthetic method involves an oxidative polymerization of 1,8-DHN in water, negating the need for multiple complex templating steps and avoiding expensive or complex chemical precursors. The well-defined morphologies of these nanomaterials were elucidated by a combination of electron microscopy and scattering methods, yielding to high-resolution 3D reconstruction based on small-angle X-ray scattering (SAXS) results. Synthetic allomelanin nanoparticles exhibit high BET areas, up to 860 m2/g, and are capable of ammonia capture up to 17.0 mmol/g at 1 bar. In addition, these nanomaterials can adsorb nerve agent simulants in solution and as a coating on fabrics with high breathability where they prevent breakthrough. We also confirmed that naturally derived fungal melanin can adsorb nerve gas simulants in solution efficiently despite lower porosity than synthetic analogues. Our approach inspires further analysis of yet to be discovered biological materials of this class where melanins with intrinsic microporosity may be linked to evolutionary advantages in relevant organisms and may in turn inspire the design of new high surface area materials.


Asunto(s)
Biopolímeros/química , Melaninas/química , Adsorción , Biopolímeros/metabolismo , Hongos/metabolismo , Melaninas/metabolismo , Nanopartículas/química , Naftoles/química , Naftoles/metabolismo , Paraoxon/química , Paraoxon/metabolismo , Porosidad , Dispersión del Ángulo Pequeño , Difracción de Rayos X
8.
J Am Chem Soc ; 143(8): 3094-3103, 2021 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-33600146

RESUMEN

Commonly known as a skin pigment, melanin has a vital role in UV radiation protection, primarily acting as a radical scavenger. However, a lesser known natural property of melanin, observed in some melanized organisms, is its capacity to adsorb toxins, including metals and organic molecules. Inspired by this, we set out to generate a synthetic porous melanin that would pave the way to enhancing the natural adsorbent properties of melanin and melanin-like materials. Here, we developed a method for the synthesis of porous polydopamine-based melanin utilizing a mesoporous silica (MS) nanoparticle template and characterized its physical properties. Through the oxidative polymerization of dopamine, followed by the etching of silica, we generated synthetic porous melanin (SPM) with the highest measured surface area of any known polydopamine-based material. The prepared SPM was effective for the uptake of various gases and organophosphate toxins, with the material exhibiting high selectivity for CO2 over CH4 and high potential for ammonia capture. Given the demonstrated advantages provided by synthetic porous melanin and melanin's role as an adsorbent in nature, we anticipate the discovery of porous analogues in biological systems.


Asunto(s)
Melaninas/química , Melaninas/síntesis química , Dióxido de Carbono/química , Indoles/química , Metano/química , Polímeros/química , Porosidad
9.
Biomater Sci ; 9(3): 653-657, 2021 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-33300507

RESUMEN

Polymeric nanoscale materials able to target and accumulate in the tumor microenvironment (TME) offer promising routes for a safer delivery of anticancer drugs. By reaching their targets before significant amounts of drug are released, such materials can reduce off-target side effects and maximize drug concentration in the TME. However, poor drug loading capacity and inefficient nanomaterial penetration into the tumor can limit their therapeutic efficacy. Herein, we provide a novel approach to achieve high loading profiles while ensuring fast and efficient drug penetration in the tumor. This is achieved by co-polymerizing light-sensitive paclitaxel with monomers responsive to tumor-associated enzymes, and assembling the resulting di-block copolymers into spherical micelles. While light exposure enables paclitaxel to decouple from the polymeric backbone into light-activated micelles, enzymatic digestion in the TME initiates its burst release. Through a series of in vitro cytotoxicity assays, we demonstrate that these light-switch micelles hold greater potency than covalently linked, non-triggered micelles, and enable therapeutic profiles comparable to that of the free drug.


Asunto(s)
Antineoplásicos , Nanopartículas , Antineoplásicos/farmacología , Portadores de Fármacos , Sistemas de Liberación de Medicamentos , Micelas , Paclitaxel/farmacología , Polímeros
10.
ACS Cent Sci ; 6(7): 1179-1188, 2020 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-32724852

RESUMEN

Human hair is naturally colored by melanin pigments, which afford myriad colors from black, to brown, to red depending on the chemical structures and specific blends. In recent decades, synthetic efforts have centered on dopamine oxidation to polydopamine, an effective eumelanin similar to the one found in humans. To date, only a few attempts at polydopamine deposition on human hair have been reported, and their translation to widespread usage and potential commercialization is still hampered by the harsh conditions employed. We reasoned that novel, mild, biocompatible approaches could be developed to establish a metal-free route to tunable, nature-inspired, long-lasting coloration of human hair. Herein, we describe synthetic and formulation routes to achieving this goal and show efficacy on a variety of human hair samples via multiple spectroscopic and imaging techniques. Owing to the mild and inexpensive conditions employed, this novel approach has the potential to replace classical harsh hair dyeing conditions that have raised concerns for several decades due to their potential toxicity.

11.
J Am Chem Soc ; 142(29): 12802-12810, 2020 07 22.
Artículo en Inglés | MEDLINE | ID: mdl-32638590

RESUMEN

Melanins are a family of heterogeneous biopolymers found ubiquitously across plant, animal, bacterial, and fungal kingdoms where they act variously as pigments and as radiation protection agents. There exist five multifunctional yet structurally and biosynthetically incompletely understood varieties of melanin: eumelanin, neuromelanin, pyomelanin, allomelanin, and pheomelanin. Although eumelanin and allomelanin have been the focus of most radiation protection studies to date, some research suggests that pheomelanin has a better absorption coefficient for X-rays than eumelanin. We reasoned that if a selenium enriched melanin existed, it would be a better X-ray protector than the sulfur-containing pheomelanin because the X-ray absorption coefficient is proportional to the fourth power of the atomic number (Z). Notably, selenium is an essential micronutrient, with the amino acid selenocysteine being genetically encoded in 25 natural human proteins. Therefore, we hypothesize that selenomelanin exists in nature, where it provides superior ionizing radiation protection to organisms compared to known melanins. Here we introduce this novel selenium analogue of pheomelanin through chemical and biosynthetic routes using selenocystine as a feedstock. The resulting selenomelanin is a structural mimic of pheomelanin. We found selenomelanin effectively prevented neonatal human epidermal keratinocytes (NHEK) from G2/M phase arrest under high-dose X-ray irradiation. Provocatively, this beneficial role of selenomelanin points to it as a sixth variety of yet to be discovered natural melanin.


Asunto(s)
Melaninas/química , Compuestos de Organoselenio/química , Selenio/química , Humanos , Queratinocitos/efectos de los fármacos , Melaninas/farmacología , Estructura Molecular , Compuestos de Organoselenio/síntesis química , Compuestos de Organoselenio/farmacología , Tamaño de la Partícula , Selenio/farmacología , Propiedades de Superficie , Rayos X
12.
Angew Chem Int Ed Engl ; 59(45): 19762-19772, 2020 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-32436259

RESUMEN

In this Minireview, we describe synthetic polymers densely functionalized with sequence-defined biomolecular sidechains. We focus on synthetic brush polymers of oligonucleotides, oligosaccharides, and oligopeptides, prepared via graft-through polymerization from biomolecule functionalized monomers. The resulting structures are brush polymers wherein a biomolecular graft is positioned at each monomer backbone unit. We describe key synthetic milestones, identify synthetic opportunities, and highlight recent advances in the field, including biological applications.


Asunto(s)
Oligonucleótidos/química , Oligopéptidos/química , Oligosacáridos/química , Polímeros/química , Microscopía de Fuerza Atómica
13.
Chem Commun (Camb) ; 56(50): 6778-6781, 2020 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-32441281

RESUMEN

In this paper, we report the preparation of paclitaxel-terminated peptide brush polymers wherein cell uptake and toxicity are tunable based on peptide sequence. Synthesis was enabled using a new paclitaxel-containing chain termination agent for ring-opening metathesis polymerization (ROMP). Critically, reverse phase HPLC could be used to efficiently separate peptide brush polymers consisting of one fluorophore and one terminal paclitaxel from crude polymer mixtures. These purified terminally-modified polymers showed greater potency than the original mixtures. Drug-terminated peptide brush polymers carrying positive charges exhibited enhanced cell uptake and cytotoxicity as compared to their neutral and negatively charged analogues.


Asunto(s)
Antineoplásicos Fitogénicos/administración & dosificación , Paclitaxel/administración & dosificación , Péptidos/administración & dosificación , Polímeros/administración & dosificación , Células A549 , Antineoplásicos Fitogénicos/química , Supervivencia Celular/efectos de los fármacos , Colorantes Fluorescentes/administración & dosificación , Colorantes Fluorescentes/química , Humanos , Paclitaxel/química , Péptidos/química , Polímeros/química
14.
Adv Healthc Mater ; 8(23): e1901105, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31664791

RESUMEN

Amphiphilic diblock copolymers are prepared by ring opening metathesis polymerization, with one block containing hydrophobic Toll-like receptor 7 (TLR7) agonists and one block containing hydrophilic peptides as substrates for matrix metalloproteinases (MMPs). A fluorescent label is incorporated into the polymer chains for in vivo imaging. Upon dialysis against aqueous solution, polymers form 15 nm spherical micelles. Subsequent exposure to MMP-9 elicits a morphological change to yield immunostimulatory microscale assemblies. The intravenous (IV) administration of the formulation to mice bearing 4T1 breast cancer tumors results in nanoparticle accumulation in tumors, reduction in primary tumor growth, and inhibition of lung metastases, as compared to saline-treated animals. Mice administered the parent immunotherapeutic small molecule (1V209) experience significantly increased plasma levels of proinflammatory cytokines IL-6, IP-10, and MCP-1 at 2 h following IV administration, whereas the nanomaterial shows no increase over saline-treated controls. These data suggest that covalently packaging low molecular weight immunotherapeutics at high weight percent loadings in enzyme-responsive nanoparticles maintains drug efficacy while decreasing immunotoxicity, providing a platform for cancer immunotherapeutic delivery.


Asunto(s)
Metaloproteinasas de la Matriz/metabolismo , Nanopartículas/administración & dosificación , Nanopartículas/química , Polímeros/metabolismo , Administración Intravenosa , Animales , Células Cultivadas , Quimiocina CCL2/sangre , Quimiocina CXCL10/sangre , Femenino , Interleucina-6/sangre , Neoplasias Mamarias Experimentales/sangre , Neoplasias Mamarias Experimentales/tratamiento farmacológico , Neoplasias Mamarias Experimentales/metabolismo , Glicoproteínas de Membrana/agonistas , Glicoproteínas de Membrana/metabolismo , Ratones , Peso Molecular , Nanopartículas/uso terapéutico , Nanoestructuras/administración & dosificación , Nanoestructuras/química , Nanoestructuras/uso terapéutico , Polímeros/química , Receptor Toll-Like 7/agonistas , Receptor Toll-Like 7/metabolismo
15.
Angew Chem Int Ed Engl ; 58(48): 17359-17364, 2019 11 25.
Artículo en Inglés | MEDLINE | ID: mdl-31595626

RESUMEN

Harnessing metal-free photoinduced reversible-deactivation radical polymerization (photo-RDRP) in organic and aqueous phases, we report a synthetic approach to enzyme-responsive and pro-apoptotic peptide brush polymers. Thermolysin-responsive peptide-based polymeric amphiphiles assembled into spherical micellar nanoparticles that undergo a morphology transition to worm-like micelles upon enzyme-triggered cleavage of coronal peptide sidechains. Moreover, pro-apoptotic polypeptide brushes show enhanced cell uptake over individual peptide chains of the same sequence, resulting in a significant increase in cytotoxicity to cancer cells. Critically, increased grafting density of pro-apoptotic peptides on brush polymers correlates with increased uptake efficiency and concurrently, cytotoxicity. The mild synthetic conditions afforded by photo-RDRP, make it possible to access well-defined peptide-based polymer bioconjugate structures with tunable bioactivity.


Asunto(s)
Micelas , Nanopartículas/química , Péptidos/química , Polímeros/química , Termolisina/química , Acrilatos/química , Aminoácidos/química , Permeabilidad de la Membrana Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Radicales Libres/química , Células HeLa , Humanos , Conformación Molecular , Procesos Fotoquímicos , Polimerizacion , Polimetil Metacrilato/química , Solventes/química , Relación Estructura-Actividad
16.
Biomacromolecules ; 20(1): 231-242, 2019 01 14.
Artículo en Inglés | MEDLINE | ID: mdl-30395472

RESUMEN

Cellular uptake and intracellular trafficking of polymer conjugates or polymer nanoparticles is typically monitored using fluorescence-based techniques such as confocal microscopy. While these methods have provided a wealth of insight into the internalization and trafficking of polymers and polymer nanoparticles, they require fluorescent labeling of the polymer or polymer nanoparticle. Because in biological media fluorescent dyes may degrade, be cleaved from the polymer or particle, or even change uptake and trafficking pathways, there is an interest in fluorescent label-free methods to study the interactions between cells and polymer nanomedicines. This article presents a first proof-of-concept that demonstrates the feasibility of NanoSIMS to monitor the intracellular localization of polymer conjugates. For the experiments reported here, poly( N-(2-hydroxypropyl) methacrylamide)) (PHPMA) was selected as a prototypical polymer-drug conjugate. This PHPMA polymer contained a 19F-label at the α-terminus, which was introduced in order to allow NanoSIMS analysis. Prior to the NanoSIMS experiments, the uptake and intracellular trafficking of the polymer was established using confocal microscopy and flow cytometry. These experiments not only provided detailed insight into the kinetics of these processes but were also important to select time points for the NanoSIMS analysis. For the NanoSIMS experiments, HeLa cells were investigated that had been exposed to the PHPMA polymer for a period of 4 or 15 h, which was known to lead to predominant lysosomal accumulation of the polymer. NanoSIMS analysis of resin-embedded and microtomed samples of the cells revealed a punctuated fluorine signal, which was found to colocalize with the sulfur signal that was attributed to the lysosomal compartments. The localization of the polymer in the endolysosomal compartments was confirmed by TEM analysis on the same cell samples. The results of this study illustrate the potential of NanoSIMS to study the uptake and intracellular trafficking of polymer nanomedicines.


Asunto(s)
Portadores de Fármacos/farmacología , Endocitosis , Ácidos Polimetacrílicos/farmacología , Supervivencia Celular/efectos de los fármacos , Endosomas/metabolismo , Células HeLa , Humanos , Lisosomas/metabolismo , Espectrometría de Masas
17.
ACS Omega ; 3(8): 9710-9721, 2018 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-31459100

RESUMEN

Chain-end-labeled polymers are interesting for a range of applications. In polymer nanomedicine, chain-end-labeled polymers are useful to study and help understand cellular internalization and intracellular trafficking processes. The recent advent of fluorescent label-free techniques, such as nanoscale secondary ion mass spectrometry (NanoSIMS), provides access to high-resolution intracellular mapping that can complement information obtained using fluorescent-labeled materials and confocal microscopy and flow cytometry. Using poly(N-(2-hydroxypropyl)methacrylamide) (PHPMA) as a prototypical polymer nanomedicine, this paper presents a synthetic strategy to polymers that contain trace element labels, such as fluorine, which can be used for NanoSIMS analysis. The strategy presented in this paper is based on reversible addition fragmentation chain transfer (RAFT) polymerization of pentafluorophenyl methacrylate (PFMA) mediated by two novel chain-transfer agents (CTAs), which contain either one (α) or two (α,ω) fluorine labels. In the first part of this study, via a number of polymerization experiments, the polymerization properties of the fluorinated RAFT CTAs were established. 19F NMR spectroscopy revealed that these fluorinated RAFT agents possess unique spectral signatures, which allow to directly monitor RAFT agent conversion and measure end-group fidelity. Comparison with 4-cyanopentanoic acid dithiobenzoate, which is a standard CTA for the RAFT polymerization of PFMA, revealed that the introduction of one or two fluorine labels does not significantly affect the polymerization properties of the CTA. In the last part of this paper, a proof-of-concept study is presented that demonstrates the feasibility of the fluorine-labeled poly(pentafluorophenyl methacrylate) polymers as platforms for the postpolymerization modification to generate PHPMA-based polymer nanomedicines.

18.
Macromol Biosci ; 17(10)2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28444959

RESUMEN

Polymer nanomedicines are very attractive to improve the delivery of chemotherapeutics. Polymer conjugates and other polymer-based nanocarriers allow to increase plasma half-life and drug bioavailability and can also be guided toward tumors using passive and active targeting strategies. Since many chemotherapeutics act on targets that are located in well-defined subcellular compartments, other important factors that contribute to an efficient therapy include cellular internalization and subsequent intracellular trafficking of the polymer nanomedicines and/or its payload to the appropriate organelle in the cytoplasm. This article provides an overview of the different approaches that have been developed to control intracellular delivery of polymer nanomedicines and discusses the different techniques that can be used to monitor these processes.


Asunto(s)
Antineoplásicos/uso terapéutico , Portadores de Fármacos , Terapia Molecular Dirigida/métodos , Nanomedicina/métodos , Nanopartículas/química , Neoplasias/tratamiento farmacológico , Antineoplásicos/farmacocinética , Transporte Biológico , Compartimento Celular , Liberación de Fármacos , Humanos , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Nanopartículas/administración & dosificación , Neoplasias/metabolismo , Neoplasias/patología , Oxidación-Reducción , Polímeros/síntesis química , Polímeros/farmacocinética
19.
Biomacromolecules ; 18(6): 1855-1865, 2017 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-28409628

RESUMEN

Inhibition of P-glycoprotein (P-gp) transporter is an attractive approach for the reversion of cancer-associated multidrug resistance (MDR). Poly(N-(2-hydroxypropyl) methacrylamide) (PHPMA)-based carriers that are able to release the anticancer drug doxorubicin in the lysosomes have shown promise to reduce P-gp mediated resistance. This is attributed to the release of the drug in close proximity to the nucleus and distant from the P-gp transporter. This work presents a strategy to maximize P-gp inhibition and enhance doxorubicin cytotoxicity in cancer cells by using a dual functional PHPMA conjugate carrying both the anticancer drug doxorubicin and the P-glycoprotein inhibitor zosuquidar (Zos). While doxorubicin was connected to the polymer backbone via a lysosomally cleavable spacer, the P-gp inhibitor Zos was attached by a hydrazone linker in order to promote release in the early stage of the endocytic process and maximize its cytosolic concentration in proximity of the P-gp transporter. Following Zos modification and determination of its ability to inhibit P-gp, conjugation to the PHPMA polymer backbone resulted in enhanced doxorubicin cytotoxicity in resistant A2780ADR ovarian carcinoma cells. Finally, the incorporation of both Dox and Zos in a single polymer carrier enhanced P-gp inhibition as compared to a control PHPMA conjugate containing only Dox.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/antagonistas & inhibidores , Dibenzocicloheptenos/farmacología , Doxorrubicina/farmacología , Portadores de Fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Metacrilatos/química , Nanopartículas/química , Quinolinas/farmacología , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Antibióticos Antineoplásicos/farmacología , Línea Celular Tumoral , Composición de Medicamentos/métodos , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Células Epiteliales/patología , Femenino , Expresión Génica , Humanos , Hidrazonas/química , Lisosomas/efectos de los fármacos , Lisosomas/metabolismo , Nanopartículas/ultraestructura , Ovario/efectos de los fármacos , Ovario/metabolismo , Ovario/patología
20.
Rev. bras. anestesiol ; 66(2): 126-132, Mar.-Apr. 2016. tab, graf
Artículo en Inglés | LILACS | ID: lil-777418

RESUMEN

ABSTRACT BACKGROUND AND OBJECTIVES: To determine the incidence of signs and symptoms of temporomandibular disorder in elective surgery patients who underwent orotracheal intubation. METHODS: This was a longitudinal controlled study with two groups. The study group included patients who underwent orotracheal intubation and a control group. We used the American Academy of Orofacial Pain questionnaire to assess the temporomandibular disorder signs and symptoms one-day postoperatively (T1), and the patients' baseline status prior to surgery (T0) was also recorded. The same questionnaire was used after three months (T2). The mouth opening amplitude was measured at T1 and T2. We considered a pvalue of less than 0.05 to be significant. RESULTS: We included 71 patients, with 38 in the study group and 33 in the control. There was no significant difference between the groups in age (study group: 66.0 [52.5-72.0]; control group: 54.0 [47.0-68.0]; p = 0.117) or in their belonging to the female gender (study group: 57.9%; control group: 63.6%; p = 0.621). At T1, there were no statistically significant differences between the groups in the incidence of mouth opening limitation (study group: 23.7% vs. control group: 18.2%;p = 0.570) or in the mouth opening amplitude (study group: 45.0 [40.0-47.0] vs. control group: 46.0 [40.0-51.0];p = 0.278). At T2 we obtained similar findings. There was no significant difference in the affirmative response to all the individual questions in the American Academy of Orofacial Pain questionnaire. CONCLUSIONS: In our population, the incidence of signs and symptoms of temporomandibular disorder of muscular origin was not different between the groups.


RESUMO JUSTIFICATIVA E OBJETIVOS: Determinar a incidência de sinais e sintomas de disfunção temporomandibular (DTM) em pacientes de cirurgia eletiva submetidos à intubação orotraqueal. MÉTODOS: Estudo longitudinal controlado com dois grupos. O grupo de estudo incluiu pacientes que foram submetidos à intubação orotraqueal e um grupo controle. Usamos o questionário da Academia Americana de Dor Orofacial (AAOP) para avaliar os sinais e sintomas da DTM no primeiro dia de pós-operatório (T1) e os estados basais dos pacientes antes da cirurgia (T0) também foram registrados. O mesmo questionário foi usado após três meses (T2). A amplitude da abertura bucal foi medida em T1 e T2. Consideramos um valor p inferior a 0,05 como significativo. RESULTADOS: No total, 71 pacientes foram incluídos, com 38 pacientes no grupo de estudo e 33 no grupo controle. Não houve diferença significativa entre os grupos quanto à idade (grupo de estudo: 66 [52,5-72]; grupo controle: 54 [47-68], p = 0,117) ou gênero feminino (grupo de estudo: 57,9%; grupo controle: 63,6%, p = 0,621). No T1, não foram encontradas diferenças estatisticamente significativas entre os grupos quanto à incidência de limitação de abertura bucal (grupo de estudo: 23,7% vs. grupo controle: 18,2%, p = 0,570) ou amplitude de abertura bucal (grupo de estudo: 45 [40-47]vs. grupo controle: 46 [40-51], p = 0,278). Em T2, os resultados obtidos foram semelhantes. Não houve diferença significativa na resposta afirmativa a todas as perguntas individuais do questionário AAOP. CONCLUSÕES: Em nossa população, a incidência de sinais e sintomas de DTM de origem muscular não foi diferente entre os grupos.


Asunto(s)
Humanos , Masculino , Femenino , Anciano , Dolor Facial/epidemiología , Trastornos de la Articulación Temporomandibular/epidemiología , Intubación Intratraqueal/métodos , Dimensión del Dolor , Dolor Facial/etiología , Incidencia , Encuestas y Cuestionarios , Procedimientos Quirúrgicos Electivos , Intubación Intratraqueal , Intubación Intratraqueal/efectos adversos , Persona de Mediana Edad
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