Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 140
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Mol Pharm ; 19(9): 3439-3449, 2022 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-35994700

RESUMEN

The combined delivery of chemotherapeutics with checkpoint inhibitors of the PD-1/PD-L1 pathway provides a new approach for cancer treatment. Small-molecule peptide inhibitors possess short production cycle, low immunogenicity, and fewer side effects; however, their potential in cancer therapy is hampered by the rapid biodegradation and a nanocarrier is needed for efficient drug delivery. Herein, anticancer drug doxorubicin (DOX) and PD-L1 inhibitor peptide P-12 are co-loaded by a lipid polymer nanocomplex based on poly(lactic-co-glycolic acid) (PLGA) and DSPE-PEG. Octaarginine (R8)-conjugated DSPE-PEG renders the LPN efficient internalization by cancer cells. The optimal nanomedicine LPN-30-R82K@DP shows a diameter of 125 nm and a DOX and P-12 loading content of 5.0 and 6.2%, respectively. LPN-30-R82K@DP exhibits good physiological stability and enhanced cellular uptake by cancer cells. It successfully induces immunogenic cell death and PD-L1 blockade in CT26 cancer cells. The in vivo antitumor study further suggests that co-loaded nanomedicine efficiently suppresses CT26 tumor growth and elicits antitumor immune response. This study manifests that lipid polymer nanocomplexes are promising drug carriers for the efficient chemo-immunotherapy of cancer.


Asunto(s)
Nanopartículas , Neoplasias , Línea Celular Tumoral , Doxorrubicina/química , Inmunoterapia , Lípidos/química , Nanopartículas/química , Neoplasias/tratamiento farmacológico , Polímeros/química
2.
Biomacromolecules ; 23(12): 5202-5212, 2022 12 12.
Artículo en Inglés | MEDLINE | ID: mdl-36287618

RESUMEN

Poor antitumor drug penetration into tumor tissues is a global challenge in clinical cancer treatment. Here, we reported a smart multistage "Trojan Horse"-inspired bovine serum albumin (BSA)-coated liposome (HBM), including the mimics of capsid and secondary BSA-coated polymeric nanoparticles (NPs) for enhancing tumor penetration and antitumor efficacy. These drug-loaded polymeric NPs possess a capsid-like component, a well-distributed nanostructure (size: 190.1 ± 4.98 nm, PDI: 0.259), and an excellent drug loading content (15.85 ± 1.36%). Meaningfully, after the smart multistage BSA-coated liposome targeted the tumor tissue, the mimics of capsid were "taken off" under the condition of tumor-specific enzymes, releasing "Heart" BSA-modified secondary NPs to increase the ability to penetrate tumor cells for enhancing antitumor efficacy. As expected, the HBM efficiently achieves high drug penetration into PAN02 tumor cells. Moreover, compared to free DOX and HM (HBM without BSA) NPs, DOX/HBM NPs exhibited the strongest tumor penetration and the highest cytotoxicity against PAN02 tumor cells both in vitro (IC50 = 0.141 µg/mL) and in vivo. This smart multistage "Trojan Horse"-inspired BSA-coated liposome should provide a new hathpace for further development of polymeric NPs in clinical treatment.


Asunto(s)
Nanopartículas , Neoplasias , Humanos , Albúmina Sérica Bovina , Liposomas/uso terapéutico , Portadores de Fármacos/uso terapéutico , Neoplasias/tratamiento farmacológico , Línea Celular Tumoral
3.
Macromol Rapid Commun ; 43(11): e2200092, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35366032

RESUMEN

Immobilizing cellulase for improving its hydrolysis activity and recyclability is critical for a cost-effective and environment-friendly conversion of cellulosic biomass. However, developing a strategy for achieving a high mass-transfer rate and good separation efficiency between an insoluble cellulose substrate and cellulase remains difficult. Instead of the traditional method, a single-enzyme molecular modification method is used in this study. To modify cellulase and provide it with a temperature-pH dual responsive property, systemized poly(acrylic-acrylonitrile) (PAA-PAN) molecular arms are used. The modified cellulase can reversibly transform between liquid and solid phases. In the liquid phase, the modified cellulase can adjust its active center, increasing its hydrolysis efficiency and separation efficiency. Cellulase and glucose products can be easily separated in the solid phase, allowing the reuse of cellulase. The results show that the modified cellulase's hydrolysis efficiency is comparable to that of free cellulase and that the modified enzyme preserves more than 60% of its initial activity after 15 batches of efficient hydrolysis. Thus, the proposed modification route considerably lowers the cost of cellulose enzymatic hydrolysis.


Asunto(s)
Celulasa , Celulosa , Celulasa/química , Celulosa/química , Glucosa/química , Hidrólisis , Temperatura
4.
Opt Express ; 29(8): 12024-12032, 2021 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-33984971

RESUMEN

Optical fibers have been widely applied to life science, such as laser delivering, fluorescence collection, biosensing, bioimaging, etc. To resolve the challenges of advanced multiphoton biophotonic applications utilizing ultrashort laser pulses, here we report a flexible diameter-oscillating fiber (DOF) with microlens endface fabricated by using Polydimethylsiloxane (PDMS) elastomers. The diameter of the DOF is designed to longitudinally vary for providing accurate dispersion management, which is important for near-infrared multiphoton biophotonics that usually involves ultrashort laser pulses. The variation range and period of the DOF's diameter can be flexibly adjusted by controlling the parameters during the fabrication, such that dispersion curves with different oscillation landscapes can be obtained. The dispersion oscillating around the zero-dispersion baseline gives rise to a minimized net dispersion as the ultrashort laser pulse passes through the DOF - reducing the temporal broadening effect and resulting in transform-limited pulsewidth. In addition, the endface of the DOF is fabricated with a microlens, which is especially useful for laser scanning/focusing and fluorescence excitation. It is anticipated that this new biocompatible DOF is of great interest for biophotonic applications, particularly multiphoton microscopy deep inside biological tissues.


Asunto(s)
Rayos Láser , Microscopía de Fluorescencia por Excitación Multifotónica/instrumentación , Fibras Ópticas , Dimetilpolisiloxanos/química , Diseño de Equipo
5.
Biomacromolecules ; 22(3): 1167-1176, 2021 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-33566577

RESUMEN

In this study, we reported a nanocomplex (PAF) of PEGylated polygalacturonic acid, 5,10,15,20-tetrakis (4-aminophenyl) porphyrin (TAPP), and Fe3+ for photodynamic therapy (PDT)-enhanced ferroptosis in cancer treatment. PAF exhibited a size of 135 nm and a TAPP and Fe3+ loading content of 6.99 and 0.77%, respectively. The singlet oxygen (1O2) generation capacity of TAPP can be activated and significantly enhanced at acidic pH (4.5-5.0). Besides, the enhanced near-infrared absorption of TAPP at acidic pH enabled a further increase in 1O2 generation capability by a near-infrared laser (760 nm). The polysaccharide-based polymer carrier offers excellent biocompatibility, and PAF displayed a proliferative effect in both normal (L929) and cancer (B16) cells. However, upon light irradiation, PAF exhibited high toxicity to B16 melanoma cells by intracellular reactive oxygen species elevation, glutathione depletion, and lipid peroxidation. PAF displayed a much better anticancer effect than the nanocomplex containing Fe3+ or TAPP alone, indicating the PDT-enhanced ferroptosis in PAF. This study suggested that PDT-enhanced ferroptosis could be a facile and robust strategy of nanotherapeutics with high potency, tumor selectivity, and excellent biocompatibility.


Asunto(s)
Ferroptosis , Nanopartículas , Neoplasias , Fotoquimioterapia , Concentración de Iones de Hidrógeno , Fármacos Fotosensibilizantes , Polímeros , Oxígeno Singlete
6.
J Nanobiotechnology ; 19(1): 14, 2021 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-33413405

RESUMEN

BACKGROUND: Nano-drug delivery systems show considerable promise for effective cancer therapy. Polymeric micelles have attracted extensive attention as practical nanocarriers for target drug delivery and controlled drug delivery system, however, the distribution of micelles and the release of the drug are difficult to trace in cancer cells. Therefore, the construction of a redox-sensitive multifunctional drug delivery system for intelligent release of anticancer drugs and simultaneous diagnostic imaging and therapy remains an attractive research subject. RESULTS: To construct a smart drug delivery system for simultaneous imaging and cancer chemotherapy, mPEG-ss-Tripp was prepared and self-assembled into redox-sensitive polymeric micelles with a diameter of 105 nm that were easily detected within cells using confocal laser scanning microscopy based on aggregation-induced emission. Doxorubicin-loaded micelles rapidly released the drug intracellularly when GSH reduced the disulfide bond. The drug-loaded micelles inhibited tumor xenografts in mice, while this efficacy was lower without the GSH-responsive disulfide bridge. These results establish an innovative multi-functional polymeric micelle for intracellular imaging and redox-triggered drug deliver to cancer cells. CONCLUSIONS: A novel redox-sensitive drug delivery system with AIE property was constructed for simultaneous cellular imaging and intelligent drug delivery and release. This smart drug delivery system opens up new possibilities for multifunctional drug delivery systems.


Asunto(s)
Antineoplásicos/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Micelas , Polímeros/química , Animales , Supervivencia Celular , Doxorrubicina/administración & dosificación , Portadores de Fármacos , Masculino , Ratones , Ratones Endogámicos BALB C , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Oxidación-Reducción
7.
BMC Plant Biol ; 19(1): 591, 2019 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-31881921

RESUMEN

BACKGROUND: Sucrose (Suc), as the precursor molecule for rubber biosynthesis in Hevea brasiliensis, is transported via phloem-mediated long-distance transport from leaves to laticifers in trunk bark, where latex (cytoplasm of laticifers) is tapped for rubber. In our previous report, six Suc transporter (SUT) genes have been cloned in Hevea tree, among which HbSUT3 is verified to play an active role in Suc loading to the laticifers. In this study, another latex-abundant SUT isoform, HbSUT5, with expressions only inferior to HbSUT3 was characterized especially for its roles in latex production. RESULTS: Both phylogenetic analysis and subcellular localization identify HbSUT5 as a tonoplast-localized SUT protein under the SUT4-clade (=type III). Suc uptake assay in baker's yeast reveals HbSUT5 to be a typical Suc-H+ symporter, but its high affinity for Suc (Km = 2.03 mM at pH 5.5) and the similar efficiency in transporting both Suc and maltose making it a peculiar SUT under the SUT4-clade. At the transcript level, HbSUT5 is abundantly and preferentially expressed in Hevea barks. The transcripts of HbSUT5 are conspicuously decreased both in Hevea latex and bark by two yield-stimulating treatments of tapping and ethephon, the patterns of which are contrary to HbSUT3. Under the ethephon treatment, the Suc level in latex cytosol decreases significantly, but that in latex lutoids (polydispersed vacuoles) changes little, suggesting a role of the decreased HbSUT5 expression in Suc compartmentalization in the lutoids and thus enhancing the Suc sink strength in laticifers. CONCLUSIONS: Our findings provide insights into the roles of a vacuolar sucrose transporter, HbSUT5, in Suc exchange between lutoids and cytosol in rubber-producing laticifers.


Asunto(s)
Hevea/metabolismo , Látex/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Proteínas de Plantas/metabolismo , Sacarosa/metabolismo , Citoplasma/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Hevea/genética , Floema/metabolismo , Corteza de la Planta/metabolismo , Regiones Promotoras Genéticas , Saccharomyces cerevisiae , Vacuolas/metabolismo
8.
J Virol ; 91(18)2017 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-28679757

RESUMEN

Enterovirus 71 (EV71) can cause hand-foot-and-mouth disease (HFMD) in young children. Severe infection with EV71 can lead to neurological complications and even death. However, the molecular basis of viral pathogenesis remains poorly understood. Here, we report that EV71 induces degradation of gasdermin D (GSDMD), an essential component of pyroptosis. Remarkably, the viral protease 3C directly targets GSDMD and induces its cleavage, which is dependent on the protease activity. Further analyses show that the Q193-G194 pair within GSDMD is the cleavage site of 3C. This cleavage produces a shorter N-terminal fragment spanning amino acids 1 to 193 (GSDMD1-193). However, unlike the N-terminal fragment produced by caspase-1 cleavage, this fragment fails to trigger cell death or inhibit EV71 replication. Importantly, a T239D or F240D substitution abrogates the activity of GSDMD consisting of amino acids 1 to 275 (GSDMD1-275). This is correlated with the lack of pyroptosis or inhibition of viral replication. These results reveal a previously unrecognized strategy for EV71 to evade the antiviral response.IMPORTANCE Recently, it has been reported that GSDMD plays a critical role in regulating lipopolysaccharide and NLRP3-mediated interleukin-1ß (IL-1ß) secretion. In this process, the N-terminal domain of p30 released from GSDMD acts as an effector in cell pyroptosis. We show that EV71 infection downregulates GSDMD. EV71 3C cleaves GSDMD at the Q193-G194 pair, resulting in a truncated N-terminal fragment disrupted for inducing cell pyroptosis. Notably, GSDMD1-275 (p30) inhibits EV71 replication whereas GSDMD1-193 does not. These results reveal a new strategy for EV71 to evade the antiviral response.


Asunto(s)
Enterovirus Humano A/fisiología , Interacciones Huésped-Patógeno , Proteínas de Neoplasias/metabolismo , Piroptosis , Línea Celular , Humanos , Péptidos y Proteínas de Señalización Intracelular , Proteínas de Unión a Fosfato , Unión Proteica , Proteolisis
9.
Biomacromolecules ; 19(7): 3140-3148, 2018 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-29883542

RESUMEN

Nanoparticle- and microsphere-based drug delivery systems (DDSs) have attracted wide attention in cancer therapy; those DDSs that are responsive to tumor environment can selectively identify tumor and normal tissues and therefore have shown enhanced anticancer efficacy and alleviated systemic toxicity. Here, tumor-pH-sensitive polymeric microspheres, which are prepared by multiblock poly(l-lactide) with pH-sensitive acetal bonds in the backbone, are employed to efficiently load water-soluble anticancer drug doxorubicin hydrochloride (DOX·HCl, drug loading content: ∼10%). The pH-sensitive DOX-loaded hollow microspheres were in the size range 2-10 µm and exhibited acid-accelerated degradation of polymer matrix and drug release, and thereby efficient in vitro cancer cell inhibition. The microspheres were further intratumorally injected into breast-tumor-bearing mice, and the in vivo anticancer experiment showed that pH-sensitive DOX-loaded microsphere showed better antitumor efficiency and prolonged life-span than its counterpart that does not have pH-responsive property. Moreover, negligible organ toxicity, especially cardiotoxicity that generally exists in DOX-involved chemotherapy where DOX is administrated by intravenous injection, was observed for DOX-loaded microspheres. Hence, tumor-pH-sensitive polymeric microspheres have appeared to be a simple and efficient platform for delivering hydrophilic anticancer drug with excellent anticancer efficacy and low systemic toxicity.


Asunto(s)
Antineoplásicos/administración & dosificación , Portadores de Fármacos/química , Microesferas , Poliésteres/química , Animales , Antineoplásicos/efectos adversos , Antineoplásicos/farmacocinética , Cardiotoxicidad , Línea Celular , Línea Celular Tumoral , Doxorrubicina/administración & dosificación , Doxorrubicina/efectos adversos , Doxorrubicina/farmacocinética , Portadores de Fármacos/farmacocinética , Liberación de Fármacos , Concentración de Iones de Hidrógeno , Ratones , Ratones Endogámicos BALB C
10.
Biomacromolecules ; 19(12): 4658-4667, 2018 12 10.
Artículo en Inglés | MEDLINE | ID: mdl-30418756

RESUMEN

Due to the high oxidative stress of the tumor microenvironment, more and more researchers have been devoted to reactive oxygen species (ROS)-responsive nanodrug delivery systems for anticancer therapy. Herein, a ROS-responsive moiety, thioacetal, was synthesized, and cinnamaldehyde (CA) was introduced in the polymer chain to trigger the generation of ROS to expect the enhancement of the ROS-responsive effect. The poly(ester-thioacetal) mPEG2k - b-(NTA-HD)12 polymer, its self-assembled micelles, and the ROS-responsive behavior were characterized by 1H NMR and DLS. The anticancer drug doxorubicin (DOX) was adopted to prepare DOX-loaded poly(ester-thioacetal) micelles. The intracellular ROS detection indicated that the mPEG2k - b-(NTA-HD)12 polymer could degrade via the high concentration of ROS in cancer cells, and the released CA stimulated mitochondria to regenerate additional ROS. The flow cytometry results indicated that the ROS-responsive polymeric micelles showed faster cellular uptake compared to the control mPEG2k - b-PCL5k micelles. The ROS responsive DOX/mPEG2k - b-(NTA-HD)12 micelles exhibited much better anticancer efficiency on both 4T1 and HeLa cancer cells than DOX/mPEG2k - b-PCL5k micelles.


Asunto(s)
Antineoplásicos/química , Doxorrubicina/farmacología , Portadores de Fármacos/química , Nanopartículas/administración & dosificación , Neoplasias/tratamiento farmacológico , Acroleína/análogos & derivados , Acroleína/química , Acroleína/farmacología , Antineoplásicos/farmacología , Supervivencia Celular/efectos de los fármacos , Doxorrubicina/química , Portadores de Fármacos/farmacología , Sistemas de Liberación de Medicamentos , Células HeLa , Humanos , Micelas , Nanopartículas/química , Poliésteres/química , Polímeros/química , Especies Reactivas de Oxígeno
11.
Macromol Rapid Commun ; 39(20): e1800212, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29947153

RESUMEN

Entrapment of living cells into a polymer network has significant potential in various fields such as biomass conversion and tissue engineering. A crucial challenge for this strategy is to provide a mild enough condition to preserve cell viability. Here, a facile and cytocompatible method to entrap living yeast cells into a poly(ethylene glycol) (PEG) network grafting from polypropylene nonwoven fabrics via visible-light-induced surface living graft crosslinking polymerization is reported. Due to the mild reaction conditions and excellent biocompatibility of PEG, the immobilized yeast cells could maintain their viability and proliferate well. The obtained composite sheet has excellent long-term stability and shows no significant efficiency loss after 25 cycles of repeated batch bioethanol fermentation. The immobilized yeast cells exhibit 18.0% higher bioethanol fermentation efficiency than free cells. This strategy for immobilization of living cells with high viability has significant potential application.


Asunto(s)
Células Inmovilizadas/química , Etanol/síntesis química , Polimerizacion , Saccharomyces cerevisiae/química , Células Inmovilizadas/metabolismo , Etanol/química , Etanol/metabolismo , Fermentación , Polietilenglicoles/química , Polipropilenos/química , Propiedades de Superficie
12.
Acta Pharmacol Sin ; 39(1): 132-139, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28795690

RESUMEN

Cancer metastasis is responsible for over 90% of breast cancer-related deaths, and inhibiting lymph node metastasis is an option to treat metastatic disease. Herein, we report the use of IR-780-loaded polymeric micelles (IPMs) for effective photothermal therapy (PTT) of breast cancer lymphatic metastasis. The IPMs were nanometer-sized micelles with a mean diameter of 25.6 nm and had good stability in simulated physiological solutions. Under 808-nm laser irradiation, IPMs exhibited high heat-generating capability in both in vitro and in vivo experiments. After intravenous injection, IPMs specifically accumulated in the tumor and metastatic lymph nodes and penetrated into these tissues. Moreover, a single IPMs treatment plus laser irradiation significantly inhibited primary tumor growth and suppressed lymphatic metastasis by 88.2%. Therefore, IPMs are an encouraging platform for PTT applications in treatment of metastatic breast cancer.


Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Indoles/uso terapéutico , Metástasis Linfática/prevención & control , Animales , Antineoplásicos/efectos de la radiación , Línea Celular Tumoral , Portadores de Fármacos/química , Portadores de Fármacos/efectos de la radiación , Portadores de Fármacos/uso terapéutico , Femenino , Calefacción , Indoles/efectos de la radiación , Terapia por Láser/métodos , Ratones Desnudos , Micelas , Tamaño de la Partícula , Fosfatidiletanolaminas/química , Fosfatidiletanolaminas/efectos de la radiación , Fosfatidiletanolaminas/uso terapéutico , Fototerapia/métodos , Polietilenglicoles/química , Polietilenglicoles/efectos de la radiación , Polietilenglicoles/uso terapéutico
13.
Bioconjug Chem ; 28(7): 1944-1954, 2017 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-28570043

RESUMEN

With the aim of obtaining effective cancer therapy with simultaneous cellular imaging, dynamic drug-release monitoring, and chemotherapeutic treatment, a polymeric micelle with aggregation-induced emission (AIE) imaging and a Forster resonance energy transfer (FRET) effect was fabricated as the drug carrier. An amphiphilic conjugate of 1H-pyrrole-1-propanoicacid (MAL)-poly(ethylene glycol) (PEG)-Tripp-bearing AIE molecules were synthesized and self-assembled into micelles to load the anticancer drug doxorubicin (DOX). Spherical DOX-loaded micelles with the mean size of 106 nm were obtained with good physiological stability (CMC, 12.5 µg/mL), high drug-loading capacity (10.4%), and encapsulation efficiency (86%). The cellular uptake behavior of DOX-loaded MAL-PEG-Tripp micelles was visible for high-quality intracellular imaging due to the AIE property. The delivery of DOX from the drug-loaded micelles was dynamic monitored by the FRET effect between the DOX and MAL-PEG-Tripp. Both in vitro (IC50, 2.36 µg/mL) and in vivo anticancer activity tests revealed that the DOX-loaded MAL-PEG-Tripp micelles exhibited promising therapeutic efficacy to cancer with low systematic toxicity. In summary, this micelle provided an effective way to fabricate novel nanoplatform for intracellular imaging, drug-delivery tracing, and chemotherapy.


Asunto(s)
Antineoplásicos/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Transferencia Resonante de Energía de Fluorescencia , Micelas , Animales , Antineoplásicos/farmacocinética , Línea Celular Tumoral , Doxorrubicina/administración & dosificación , Doxorrubicina/farmacocinética , Liberación de Fármacos , Monitoreo de Drogas , Humanos , Ratones , Ratones Endogámicos BALB C , Polietilenglicoles , Polímeros , Ensayos Antitumor por Modelo de Xenoinjerto
14.
Langmuir ; 33(22): 5577-5584, 2017 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-28514852

RESUMEN

The use of the mixed catalytic system with several enzymes can provide multiple benefits in terms of the cost, simplification of a multistep reaction, and effectiveness of complex chemical reactions. Although study of different enzyme coimmobilization systems has attracted increasing attention in recent years, separately immobilizing enzymes which can not coexist on one support is still one of the great challenges. In this paper, a simple and effective strategy was introduced to separately encapsulate incompatible trypsin and transglutaminase (TGase) into different poly(ethylene glycol) (PEG) network layer grafted on low-density polyethylene (LDPE) film via visible light induced living photografting polymerization. As a proof of concept, this dual-enzyme separately loaded film was used to catalyze the synthesis of a new target antitumor drug LTV-azacytidine. The final results demonstrated that this strategy could maintain higher activities of both enzymes than the mixed coimmobilization method. And the mass spectra analysis results demonstrated that LTV-azacytidine was successfully synthesized. We believe that this facile and mild separately immobilizing incompatible enzyme strategy has great application potential in the field of biocatalysis.


Asunto(s)
Polietilenglicoles/química , Enzimas Inmovilizadas , Luz , Polimerizacion
15.
Org Biomol Chem ; 15(43): 9176-9185, 2017 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-29072771

RESUMEN

As the implications of reactive oxygen species (ROS) are elucidated in many diseases, ROS-responsive nanoparticles are attracting great interest from researchers. In this work, a ROS sensitive thioketal (TK) moiety with a π-conjugated structure was introduced into biodegradable methoxy poly(ethylene glycol)-thioketal-poly(ε-caprolactone)mPEG-TK-PCL micelles as a linker, which was designed to speed up the drug release and thus enhance the therapeutic efficacy. The micelle showed a high drug loading content of 12.8% and excellent stability under physiological conditions because of the evocation of π-π stacking and hydrophobic interactions with the anticancer drug doxorubicin (DOX). The polymeric micelle presented a better drug carrier capacity and higher in vitro anticancer efficacy towards cancer cells. The in vivo study showed that DOX-loaded mPEG-TK-PCL micelles displayed lower toxicity towards normal cells and remarkably enhanced antitumor efficacy. This research provides a way to design potential drug carriers for efficient cancer chemotherapy.


Asunto(s)
Acetales/química , Portadores de Fármacos/química , Micelas , Polímeros/química , Animales , Transporte Biológico , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Doxorrubicina/química , Doxorrubicina/farmacología , Portadores de Fármacos/metabolismo , Liberación de Fármacos , Cetonas/química , Ratones
16.
Acta Pharmacol Sin ; 38(6): 924-930, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28504249

RESUMEN

Cancer metastasis is the primary cause of high mortality in breast cancer patients. In this study, we loaded an anti-cancer drug, cabazitaxel (CTX), into polymeric micelles (CTX-loaded polymeric micelles, PCMs), and explored their therapeutic efficacy in breast cancer metastasis. The characteristics of PCMs were investigated, and their anti-metastatic efficacy was assessed using in vitro and in vivo evaluations. PCMs had an average diameter of 50.13±11.96 nm with a CTX encapsulation efficiency of 97.02%±0.97%. PCMs could be effectively internalized into metastatic 4T1 breast cancer cells in vitro. CTX (10 ng/mL) or an equivalent concentration in PCMs did not significantly affected the viability of 4T1 cells, but dramatically decreased the cell migration activities. In an orthotopic metastatic breast cancer model, intravenously administered PCMs could be efficiently delivered to the tumor sites, resulting in a 71.6% inhibition of tumor growth and a 93.5% reduction of lung metastases. Taken together, our results verify the anti-metastatic efficacy of PCMs, thus providing an encouraging strategy for treating breast cancer metastasis.


Asunto(s)
Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Lactatos/química , Polietilenglicoles/química , Taxoides/farmacología , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/química , Neoplasias de la Mama/patología , Neoplasias de la Mama/secundario , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Humanos , Lactatos/administración & dosificación , Neoplasias Mamarias Experimentales/tratamiento farmacológico , Neoplasias Mamarias Experimentales/patología , Neoplasias Mamarias Experimentales/secundario , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Micelas , Tamaño de la Partícula , Polietilenglicoles/administración & dosificación , Relación Estructura-Actividad , Propiedades de Superficie , Taxoides/administración & dosificación , Taxoides/química
17.
J Craniofac Surg ; 28(6): 1418-1424, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28692513

RESUMEN

OBJECTIVES: The objective of this study was to investigate the viability and biomechanics of diced cartilage blended with platelet-rich plasma (PRP) and wrapped with poly (lactic-co-glycolic) acid (PLGA) membrane in a rabbit model. METHODS: A total of 10 New Zealand rabbits were used for the study. Cartilage grafts were harvested from 1 side ear. The grafts were divided into 3 groups for comparison: bare diced cartilage, diced cartilage wrapped with PLGA membrane, and diced cartilage blended with PRP and wrapped with PLGA membrane. Platelet-rich plasma was prepared using 8 mL of auricular blood. Three subcutaneous pockets were made in the backs of the rabbits, and the grafts were placed in these pockets. The subcutaneous implant tests were conducted for safety assessment of the PLGA membrane in vivo. All of the rabbits were sacrificed at the end of 3 months, and the specimens were collected. The sections were stained with hematoxylin and eosin, toluidin blue, and collagen II immunohistochemical. Simultaneously, biomechanical properties of grafts were assessed. RESULTS: This sample of PLGA membrane was conformed to the current standard of biological evaluation of medical devices. Moderate resorption was seen at the end of 3 months in the gross assessment in diced cartilage wrapped with PLGA membrane, while diced cartilage blended with PRP had no apparent resorption macroscopically and favorable viability in vivo after 3 months, and the histological parameters supported this. Stress-strain curves for the compression test indicated that the modulus of elasticity of bare diced cartilage was 7.65 ±â€Š0.59 MPa; diced cartilage wrapped with PLGA membrane was 5.98 ±â€Š0.45 MPa; and diced cartilage blended with PRP and wrapped with PLGA membrane was 7.48 ±â€Š0.55 MPa, respectively. CONCLUSIONS: Diced cartilage wrapped with PLGA membrane had moderate resorption macroscopically after 3 months. However, blending with PRP has beneficial effects in improving the viability of diced cartilages. Additionally, the compression modulus of diced cartilage blended with PRP and wrapped with PLGA membrane was similar to bare diced cartilage.


Asunto(s)
Cartílago , Ácido Láctico/farmacología , Plasma Rico en Plaquetas , Ácido Poliglicólico/farmacología , Supervivencia Tisular , Animales , Cartílago/efectos de los fármacos , Cartílago/fisiología , Módulo de Elasticidad , Membranas Artificiales , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Conejos , Supervivencia Tisular/efectos de los fármacos , Supervivencia Tisular/fisiología
18.
Macromol Rapid Commun ; 37(19): 1611-1617, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27501990

RESUMEN

The precise construction of a hierarchical complex pattern on substrates is required for numerous applications. Here, a strategy to fabricate well-defined hierarchical three dimensional (3D) patterns on polymer substrate is developed. This technique, which combines photolithography and visible light-induced surface initiated living graft crosslinking polymerization (VSLGCP), can effectively graft 3D patterns onto polymer substrate with high fidelity and controllable height. Owing to the living nature of VSLGCP, hierarchical 3D patterns can be prepared when a sequential living graft crosslinking process is performed on the first formed patterns. As a proof-of-concept, a reactive two layer 3D pattern with a morphology of lateral stripe on vertical stripe is prepared and employed to separately immobilize model biomolecules, e.g., biotin and IgG. This two component pattern can specifically interact with corresponding target proteins successfully, indicating that this strategy has potential applications in the fabrication of polymer-based multicomponent biomolecule microarrays.


Asunto(s)
Luz , Polímeros/química , Tamaño de la Partícula , Procesos Fotoquímicos , Polímeros/síntesis química , Propiedades de Superficie
19.
J Virol ; 88(17): 9830-41, 2014 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-24942571

RESUMEN

UNLABELLED: Enterovirus 71 (EV71) causes hand, foot, and mouth disease in young children and infants. Severe infection with EV71 can lead to various neurological complications or fatal diseases. However, the mechanism of EV71 pathogenesis is poorly understood. Emerging evidence suggests that EV71 modulates type I interferon (IFN) and cytokine responses. Here, we show that EV71 disables components of the TAB2 complex through the 3C protein. When expressed in mammalian cells, EV71 3C interacts with TAB2 and TAK1, which inhibits NF-κB activation. Furthermore, 3C mediates cleavage of TAB2 and its partners, which requires the protease activity. H40D or C147S substitution in the 3C active sites abolishes its activity, whereas R84Q or V154S substitution in the RNA binding domain has no effect. The 3C protein targets TAB2 at Q113-S114, TAK1 at Q360-S361, TAB1 both at Q414-G415 and Q451-S452, and TAB3 at Q173-G174 and Q343-G344. Importantly, overexpression of TAB2 inhibits EV71 replication, whereas addition of cleaved fragments has no effect. Thus, an equilibrium between the TAB2 complex and EV71 3C represents a control point of viral infection. These results suggest that TAK1/TAB1/TAB2/TAB3 cleavage mediated by EV71 may be a mechanism to interfere with inflammatory responses. IMPORTANCE: The TAK1 complex plays a critical role in the activation of NF-κB and cytokine production. However, little is known about its connection to enterovirus 71 (EV71). We demonstrate that EV71 3C suppresses cytokine expression via cleavage of the TAK1 complex proteins. EV71 3C interacts with TAB2 and TAK1. Furthermore, overexpression of TAB2 inhibits EV71 replication, whereas addition of cleaved fragment has no effect. These results suggest that the interplay of EV71 and the TAK1 complex influences the outcome of viral infection.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Cisteína Endopeptidasas/metabolismo , Citocinas/antagonistas & inhibidores , Enterovirus Humano A/fisiología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Quinasas Quinasa Quinasa PAM/metabolismo , Proteínas Virales/metabolismo , Proteasas Virales 3C , Sustitución de Aminoácidos , Línea Celular , Cisteína Endopeptidasas/genética , Enterovirus Humano A/genética , Enterovirus Humano A/inmunología , Enterovirus Humano A/patogenicidad , Humanos , Hidrólisis , Evasión Inmune , Mutagénesis Sitio-Dirigida , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Proteínas Virales/genética
20.
Anesth Analg ; 121(6): 1580-5, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26496368

RESUMEN

BACKGROUND: The effects of general anesthetics on the hypothalamus-pituitary-adrenal axis and cortisol release in children are poorly characterized. Normal, daily fluctuation of cortisol levels complicates assessment of these effects. This study aimed to characterize the effects of etomidate compared with propofol on the normal cortisol secretory pattern in children undergoing urologic surgery by using a salivary cortisol assay. METHODS: In this prospective, randomized, double-blind, controlled study, we recruited 80 children aged 3 to 12 years assigned ASA physical status I who were scheduled for urologic surgery and 11 healthy child volunteers. Before surgery, cortisol levels of the 11 volunteers and 15 study patients were tested from 7:00 AM to 9:00 PM every hour for 1 day. The study patients were then randomly allocated into an etomidate group and a propofol group, receiving etomidate 0.3 mg/kg (n = 38) or propofol 2 mg/kg (n = 39) and midazolam 0.1 mg/kg, fentanyl 2 µg/kg, and rocuronium 0.6 mg/kg for induction, respectively. The cortisol levels of the patients were assessed continuously for 2 days postoperatively. RESULTS: The cortisol levels of the etomidate group were continuously and significantly lower than those of the propofol group from the time of discharge from the postanesthesia care unit (approximately 2:00 PM) until 8:00 AM the next morning (all P < 0.0001) and were significantly lower than before surgery at the same time points (all P < 0.0001). Except at 11:00 AM just before the operation, no significant differences in cortisol levels were detected before and after the operation in the propofol group (P max = 0.476, P min = 0.002). Also, no significant differences in clinical outcomes were detected between the 2 groups undergoing surgery (all P > 0.070). CONCLUSIONS: Compared with propofol, a single induction dose of etomidate suppressed postoperative cortisol levels in healthy children undergoing urologic surgery. This suppression lasted approximately 24 hours and was not associated with any changes in clinical outcomes.


Asunto(s)
Anestésicos Intravenosos/administración & dosificación , Etomidato/administración & dosificación , Hidrocortisona/análisis , Propofol/administración & dosificación , Procedimientos Quirúrgicos Urológicos/tendencias , Biomarcadores/análisis , Niño , Preescolar , Método Doble Ciego , Femenino , Humanos , Masculino , Estudios Prospectivos , Saliva/química , Saliva/efectos de los fármacos , Procedimientos Quirúrgicos Urológicos/efectos adversos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA