RESUMEN
Polycomb repressive complex 2 (PRC2) suppresses gene transcription by methylating lysine 27 of histone H3 (H3K27) and plays critical roles in embryonic development. Among the core PRC2 subunits, EZH2 is the catalytic subunit and EED allosterically activates EZH2 upon binding trimethylated H3K27 (H3K27me3). Activating mutations on Y641, A677, and A687 within the enzymatic SET (Su(Var)3 to 9, Enhancer-of-zeste, and Trithorax) domain of EZH2 have been associated with enhanced H3K27me3 and tumorigenicity of many cancers including B-cell lymphoma and melanoma. To tackle the critical residues outside the EZH2 SET domain, we examined EZH2 mutations in lymphoma from cancer genome databases and identified a novel gain-of-function mutation W113C, which increases H3K27me3 in vitro and in vivo and promotes CDKN2A silencing to a similar level as EZH2 Y641F. Different from other gain-of-function mutations, this mutation is located in the SET-activation loop at the EZH2 N terminus, which stabilizes the SET domain and facilitates substrate binding. This may explain how the W113C mutation increases PRC2 activity. Tazemetostat is a Food and Drug Administration-approved EZH2-binding inhibitor for follicular lymphoma treatment. Intriguingly, the W113C mutation leads to tazemetostat resistance in both H3K27 methylation and tumor proliferation. Another class of allosteric PRC2 inhibitor binding EED overcomes the resistance, effectively decreases H3K27me3, and blocks tumor proliferation in cells expressing EZH2 W113C. As this mutation is originally identified from lymphoma samples, our results demonstrated its activating characteristic and the deleterious consequence, provide insights on PRC2 regulation, and support the continued exploration of treatment optimization for lymphoma patients.
Asunto(s)
Resistencia a Antineoplásicos , Mutación con Ganancia de Función , Linfoma de Células B , Humanos , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Histonas/metabolismo , Linfoma de Células B/tratamiento farmacológico , Linfoma de Células B/genética , Mutación , Complejo Represivo Polycomb 2/genéticaRESUMEN
Exploring ideal nanocarriers for drug delivery systems has encountered unavoidable hurdles, especially the conflict between enhanced cellular uptake and prolonged blood circulation, which have determined the final efficacy of cancer therapy. Here, based on controlled self-assembly, surface structure variation in response to external environment was constructed toward overcoming the conflict. A novel micelle with mixed shell of hydrophilic poly(ethylene glycol) PEG and pH responsive hydrophobic poly(ß-amino ester) (PAE) was designed through the self-assembly of diblock amphiphilic copolymers. To avoid the accelerated clearance from blood circulation caused by the surface exposed targeting group c(RGDfK), here c(RGDfK) was conjugated to the hydrophobic PAE and hidden in the shell of PEG at pH 7.4. At tumor pH, charge conversion occurred, and c(RGDfK) stretched out of the shell, leading to facilitated cellular internalization according to the HepG2 cell uptake experiments. Meanwhile, the heterogeneous surface structure endowed the micelle with prolonged blood circulation. With the self-regulated multifunctional collaborated properties of enhanced cellular uptake and prolonged blood circulation, successful inhibition of tumor growth was achieved from the demonstration in a tumor-bearing mice model. This novel nanocarrier could be a promising candidate in future clinical experiments.
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Antineoplásicos/química , Portadores de Fármacos/química , Nanopartículas/química , Animales , Línea Celular Tumoral , Sistemas de Liberación de Medicamentos/métodos , Femenino , Células Hep G2 , Humanos , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Micelas , Polietilenglicoles/química , Polímeros/químicaRESUMEN
Polyamidoamine (PAMAM) dendrimers have been widely used as drug carriers, non-viral gene vectors and imaging agents. However, the use of dendrimers in biological system is constrained because of inherent toxicity and organ accumulation. In this study, the strategy of acetylation and PEGylation-acetylation was used to minimize PAMAM dendrimers toxicities and to improve their biodistribution and pharmacokinetics for medical application. PEGylated-acetylated PAMAM (G4-Ac-PEG) dendrimers were synthesized by PEGylation of acetylated PAMAM dendrimer of generation 4 (G4) with acetic anhydride and polyethylene glycol (PEG) 3.4 k. To investigate the cytotoxicity and in vivo biodistribution of the conjugates, in vitro cell viability analysis, Iodine-125 (125I) imaging, tissue distribution and hematoxylin-eosin (HE) staining were performed. We find that acetylation and PEGylation-acetylation essentially eliminates the inherent dendrimer cytotoxicity in vitro. Planar gamma (gamma) camera imaging revealed that all the conjugates were slowly eliminated from the body, and higher abdominal accumulation of acetylation PAMAM dendrimer was observed. Tissue distribution analysis showed that PEGylated-acetylated dendrimers have longer blood retention and lower accumulation in organs such as the kidney and liver than the non-PEGylated-acetylated dendrimers, but acetylation only can significantly increase the accumulation of G4 in the kidney and decrease the concentration in blood. Histology results reveal that no obvious damage was observed in all groups after high dose administration. This study indicates that PEGylation-acetylation could improve the blood retention, decrease organ accumulation, and improve pharmacokinetic profile, which suggests that PEGylation-acetylation provides an alternative method for PAMAM dendrimers modification.
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Dendrímeros/síntesis química , Dendrímeros/farmacocinética , Polietilenglicoles/química , Acetilación , Animales , Dendrímeros/administración & dosificación , Células HEK293 , Humanos , Infusiones Intravenosas , Radioisótopos de Yodo/administración & dosificación , Masculino , Ratones , Ratones Endogámicos BALB C , Distribución TisularRESUMEN
EZH2 is the catalytic subunit of the histone methyltransferase Polycomb Repressive Complex 2 (PRC2), and its somatic activating mutations drive lymphoma, particularly the germinal center B-cell type. Although PRC2 inhibitors, such as tazemetostat, have demonstrated anti-lymphoma activity in patients, the clinical efficacy is not limited to EZH2-mutant lymphoma. In this study, Activin A Receptor Type 1 (ACVR1), a type I Bone Morphogenetic Protein (BMP) receptor, is identified as critical for the anti-lymphoma efficacy of PRC2 inhibitors through a whole-genome CRISPR screen. BMP6, BMP7, and ACVR1 are repressed by PRC2-mediated H3K27me3, and PRC2 inhibition upregulates their expression and signaling in cell and patient-derived xenograft models. Through BMP-ACVR1 signaling, PRC2 inhibitors robustly induced cell cycle arrest and B cell lineage differentiation in vivo. Remarkably, blocking ACVR1 signaling using an inhibitor or genetic depletion significantly compromised the in vitro and in vivo efficacy of PRC2 inhibitors. Furthermore, high levels of BMP6 and BMP7, along with ACVR1, are associated with longer survival in lymphoma patients, underscoring the clinical relevance of this study. Altogether, BMP-ACVR1 exhibits anti-lymphoma function and represents a critical PRC2-repressed pathway contributing to the efficacy of PRC2 inhibitors.
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Linfoma de Células B , Linfoma , Humanos , Complejo Represivo Polycomb 2/genética , Complejo Represivo Polycomb 2/metabolismo , Transducción de Señal/fisiología , Receptores de Activinas Tipo I/genética , Receptores de Activinas Tipo I/metabolismoRESUMEN
The miserable targeting performance of nanocarriers for cancer therapy arises largely from the rapid clearance from blood circulation and the major accumulation in the organs of the reticuloendothelial system (RES), leading to inefficient enhanced permeability and retention (EPR) effect after intravenous injection (i.v.). Herein, we reported an efficient method to prolong the blood circulation of nanoparticles and decrease their deposition in liver and spleen. In this work, we fabricated a series of mixed shell micelles (MSMs) with approximately the same size, charge and core composition but with varied hydrophilic/hydrophobic ratios in the shell through spontaneously self-assembly of block copolymers poly(ethylene glycol)-block-poly(l-lysine) (PEG-b-PLys) and poly(N-isopropylacrylamide)-block-poly(aspartic acid) (PNIPAM-b-PAsp) in aqueous medium. The effect of the surface heterogeneity on the in vivo biodistribution was systematically investigated through in vivo tracking of the (125)I-labeled MSMs determined by Gamma counter. Compared with single PEGylated micelles, some MSMs were proved to be significantly efficient with more than 3 times lower accumulation in liver and spleen and about 6 times higher concentration in blood at 1 h after i.v.. The results provide us a novel strategy for future development of long-circulating nanocarriers for efficient cancer therapy.
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Portadores de Fármacos , Nanopartículas , Polímeros/farmacología , Distribución Tisular/efectos de los fármacos , Transporte Biológico , Supervivencia Celular/efectos de los fármacos , Interacciones Hidrofóbicas e Hidrofílicas , Hígado/metabolismo , Micelas , Sistema Mononuclear Fagocítico/metabolismo , Neoplasias/tratamiento farmacológico , Bazo/metabolismo , Propiedades de SuperficieRESUMEN
To clarify the functional orientation of community health nurses in the continuous care of patients with chronic diseases and to encourage community nurses to play their expected roles in extended nursing work. In this study, conducted from May to July 2020, the staff of Shanghai Community Health Service Center were sampled, and representative medical staff were selected for in-depth interviews and focus group discussions. Eighteen community medical staff members participated. The functions of community nurses in the continuous care of patients with chronic diseases are mainly as follows: â undertaking individualized projects for patients' continuous treatment, nursing and rehabilitation; â¡ creating "peer education" conditions for patients; ⢠providing supportive care to family caregivers; and ⣠participating in the whole process of family doctor team health management. The results provide a reminder for nurse managers that under the new mission, community nurses need "one specialty and multiple abilities," appropriate nursing technology and good health management skills. The training of community nurses should better meet the practical needs of patients with chronic diseases.
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Enfermeras y Enfermeros , Humanos , China , Investigación Cualitativa , Continuidad de la Atención al Paciente , Enfermedad CrónicaRESUMEN
The methyltransferase Polycomb Repressive Complex 2 (PRC2), composed of EZH2, SUZ12, and EED subunits, is associated with transcriptional repression via tri-methylation of histone H3 on lysine 27 residue (H3K27me3). PRC2 is a valid drug target, as the EZH2 gain-of-function mutations identified in patient samples drive tumorigenesis. PRC2 inhibitors have been discovered and demonstrated anti-cancer efficacy in clinic. However, their pharmacological mechanisms are poorly understood. MAK683 is a potent EED inhibitor in clinical development. Focusing on MAK683-sensitive tumors with SMARCB1 or ARID1A loss, we identified a group of PRC2 target genes with high H3K27me3 signal through epigenomic and transcriptomic analysis. Multiple senescence-associated secretory phenotype (SASP) genes, such as GATA4, MMP2/10, ITGA2 and GBP1, are in this group besides previously identified CDKN2A/p16. Upon PRC2 inhibition, the de-repression of SASP genes is detected in multiple sensitive models and contributes to decreased Ki67+, extracellular matrix (ECM) reorganization, senescence associated inflammation and tumor regression even in CDKN2A/p16 knockout tumor. And the combination of PRC2 inhibitor and CDK4/6 inhibitor leads to better effect. The genes potential regulated by PRC2 in neuroblastoma samples exhibited significant enrichment of ECM and senescence associated inflammation, supporting the clinical relevance of our results. Altogether, our results unravel the pharmacological mechanism of PRC2 inhibitors and propose a combination strategy for MAK683 and other PRC2 drugs.
Asunto(s)
Neoplasias , Complejo Represivo Polycomb 2 , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Histonas/química , Humanos , Inflamación , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Complejo Represivo Polycomb 2/genética , Complejo Represivo Polycomb 2/metabolismo , Fenotipo Secretor Asociado a la SenescenciaRESUMEN
miR-92a-3p (microRNA-92a-3p) has been reported to be dysregulated in several cancers, and as such, it is considered to be a cancer-related microRNA. However, the influence of miR-92a-3p on biological behaviors in cervical cancer (CC) still remains unclear. Quantitative real-time PCR was used to detect miR-92a-3p levels in CC stem cells. Here, Cell Counting Kit-8 (CCK8) assay, Transwell cell invasion assay and flow cytometry assay were used to characterize the effects that miR-92a-3p and large tumor suppressor l (LATS1) had on proliferation, invasion and cell cycle transition. The luciferase reporter gene assay was used to verify the targeting relationship between miR-92a-3p and LATS1. Western Blotting was used to investigate the related signaling pathways and proteins. Data from The Cancer Genome Atlas (TCGA) showed that miR-92a-3p was upregulated in CC tissues and closely associated with overall survival. miR-92a-3p promoted proliferation, invasion and cell cycle transition in CC stem cells. The luciferase reporter assay showed that miR-92a-3p bound to the 3'-untranslated region (3'-UTR) of the LATS1 promoter. LATS1 inhibited proliferation, invasion and cell cycle transition. Results measured by Western Blotting showed that LATS1 downregulated expressions of transcriptional co-activator with PDZ-binding motif (TAZ), vimentin and cyclin E, but upregulated the expression of E-cadherin. Re-expression of LATS1 partly reversed the effects of miR-92a-3p on proliferation, invasion and cell cycle transition, as well as on TAZ, E-cadherin, vimentin, and cyclin E. miR-92a-3p promoted the malignant behavior of CC stem cells by targeting LATS1, which regulated TAZ and E-cadherin.
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The utilization of nanotechnology to deliver vaccines and modulate immunity has shown great potential in cancer therapy. Peptide-based supramolecular hydrogels as novel vaccine adjuvants have been found to effectively improve the immune response and tumor curative effect. In this study, we designed a set of reduction-responsive self-assembled peptide precursors (Fbp-GDFDFDYD(E, S, or K)-ss-ERGD), which can be reduced by glutathione (GSH) into Fbp-GDFDFDYD(E, S or K)-SH for forming of hydrogel with different surface properties (E-gel, S-gel, and K-gel, respectively). Using the same method, co-assembled hydrogel vaccines (E-vac, S-vac, and K-vac, respectively) can also be prepared by mixing different precursors with antigens before GSH reduction. Through TEM observation of the nanostructure, we found that all the co-assembled hydrogels, especially K-vac, possessed much denser and more unified nanofiber networks as compared with antigen-free hydrogels, which were very suitable for antigen storage and vaccine delivery. Although the three peptides adopted similar ß-sheet secondary structures, the mechanical properties of their resulted co-assembled hydrogel vaccines were obviously different. Compared to E-vac, S-vac had a much weaker mechanical property, while K-vac had a much higher. In vivo experiments, co-assembled hydrogel vaccines, especially K-vac, also promoted antibody production and anti-tumor immune responses more significantly than the other two vaccines. Our results demonstrated that co-assembled hydrogels formed by peptides and antigens co-assembly could act as effective vaccine delivery systems for boosting antibody production, and different immune effects can be acquired by tuning the surface properties of the involved self-assembling peptides.
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Drug-resistant bacterial infections have stolen the spotlight in recent years as stubborn diseases intimidating public health, thus urgently requiring the development of innovative treatment strategies with high antibacterial efficiency and low bacterial resistance. Here, a polymeric antimicrobial with synergistic chemo-photodynamic therapy function is fabricated to combat drug-resistant bacterial infections. In this strategy, polymeric micelles based on amphiphilic poly(aspartic acid)-block-poly(ε-caprolactone) (PAsp-b-PCL) are used as nanocarriers to encapsulate a photosensitizer protoporphyrin IX (PpIX) in the micellar core, which then undergo silver nanoparticle decoration on the micellar shell through an in situ reduction method. Compared with mono-therapy, the combination of silver nanoparticle decoration and light-activatable PpIX enables the resulting polymeric antimicrobial to exert chemo-photodynamic activity to kill drug-resistant bacteria more potently in vitro. Furthermore, the prepared polymeric antimicrobials with synergistic antibacterial activity show robust eradication efficacy against subcutaneous infections induced by drug-resistant Staphylococcus aureus in a murine model. Therefore, our study provides a simple and potent strategy to realize combination therapy for eradicating drug-resistant bacterial infections.
Asunto(s)
Antiinfecciosos , Nanopartículas del Metal , Staphylococcus aureus Resistente a Meticilina , Fotoquimioterapia , Animales , Ratones , Micelas , PlataRESUMEN
With the emergence of drug-resistant bacteria, conventional antibiotics are becoming increasingly ineffective for the treatment of bacterial infections. Nanomaterial-modified antibiotics, denoted as "nanoantibiotics", can usually circumvent most of the shortcomings of conventional antibiotics, thus improving antibacterial activities. Here, we developed triclosan-based supramolecular hydrogel nanoantibiotics by conjugating small molecule antibiotic triclosan (TCS) to self-assembling peptides. The resultant nanoantibiotics presented many beneficial characteristics: (i) a stable three-dimensional nanofiber structure; (ii) increased TCS solubility by 850-fold; (iii) acid-responsive TCS release; (iv) favorable biocompatibility. In consequence, the nanoantibiotics showed potent in vitro broad-spectrum antibacterial activities against both Gram-positive and Gram-negative bacteria based on the cooperative effect of antibiotic TCS and the nanostructure-induced bacterial membrane disruption. Furthermore, the TCS-based supramolecular hydrogel nanoantibiotics exhibited enhanced antibacterial activities with low side effects, according to the in vivo antibacterial evaluation at the macro and micro level. Therefore, the simple and effective hydrogel nanoantibiotics developed here hold great potential for the treatment of intractable bacterial infections.
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Antibacterianos , Triclosán , Antibacterianos/farmacología , Bacterias Gramnegativas , Bacterias Grampositivas , HidrogelesRESUMEN
Insig-2 is an ER membrane protein negatively controlling lipid biosynthesis. Here, we find that Insig-2 is increased in the tissues, including liver, but unaltered in the muscle of gp78-deficient mice. In hepatocytes and undifferentiated C2C12 myoblasts, Insig-2 is ubiquitylated on Cys215 by gp78 and degraded. However, the C215 residue is oxidized by elevated reactive oxygen species (ROS) during C2C12 myoblasts differentiating into myotubes, preventing Insig-2 from ubiquitylation and degradation. The stabilized Insig-2 downregulates lipogenesis through inhibiting the SREBP pathway, helping to channel the carbon flux to ATP generation and protecting myotubes from lipid over-accumulation. Evolutionary analysis shows that the YECK (in which C represents Cys215 in human Insig-2) tetrapeptide sequence in Insig-2 is highly conserved in amniotes but not in aquatic amphibians and fishes, suggesting it may have been shaped by differential selection. Together, this study suggests that competitive oxidation-ubiquitylation on Cys215 of Insig-2 senses ROS and prevents muscle cells from lipid accumulation.
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Cisteína/metabolismo , Proteínas de la Membrana/metabolismo , Receptores del Factor Autocrino de Motilidad/metabolismo , Ubiquitinación , Anfibios , Animales , Células CHO , Línea Celular , Cricetulus , Regulación hacia Abajo , Evolución Molecular , Peces , Hepatocitos/metabolismo , Humanos , Metabolismo de los Lípidos , Lipogénesis , Hígado/metabolismo , Masculino , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Células Musculares/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Mioblastos/metabolismo , Oxidación-Reducción , Especies Reactivas de Oxígeno/metabolismo , Receptores del Factor Autocrino de Motilidad/genética , Análisis de Secuencia de Proteína , Proteínas de Unión a los Elementos Reguladores de Esteroles/metabolismo , TranscriptomaRESUMEN
Anoikis is a specific form of programmed cell death induced by loss of contact between cells and extracellular matrices or other cells. Only tumor cells that are resistant to anoikis can survive in the state of detachment from the primary tissue during the early stages of metastasis. The ability to resist anoikis is crucial for cancer cell metastasis. ILF2 is a proto-oncogene previously studied in glioma, NSCLC, esophageal cancer and pancreatic ductal carcinoma. The results from the present study revealed that the transcription factor interleukin enhancer-binding factor 2 (ILF2) was highly expressed in non-small cell lung cancer (NSCLC) cell lines compared with in normal cell lines. ChIP and luciferase reporter gene assays demonstrated that ILF2 inhibited the expression level of the tumor suppressor gene phosphatase and tensin homolog (PTEN) by directly binding to its upstream regulatory region. Furthermore, the results from the detection of cell adhesion and apoptosis in cell suspension culture demonstrated that this mechanism enabled NSCLC cells to reduce adherence to the matrix and to survive in this abnormal state. These results suggested that ILF2 may promote the anchorage-independence of NSCLC cells through the suppression of PTEN.
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Combination therapy with different functional drugs has been proved to be an effective strategy for cancer treatments by achieving cooperative therapeutic efficacy and reducing drug side effects. In this study, a novel combination anticancer system was designed by coating silver nanoparticles in the poly(aspartic acid) (PAsp) shell of polymer micelle via the in situ reduction of silver ions and encapsulating doxorubicin (DOX) into the micellar poly(ε-caprolactone) (PCL) core through hydrophobic interaction. This combination system not only avoided aggregation of the silver nanoparticles but also improved the bioavailability of DOX. As a result, it exhibited enhanced antitumor activity against HepG2 tumor cells compared with single silver-coated or DOX-loaded nanoparticles because of the combined anticancer effects of nanosilver and DOX. Therefore, this combination therapeutic system could be a potential candidate for enhanced anticancer therapy.
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Nanopartículas del Metal , Doxorrubicina , Portadores de Fármacos , Células Hep G2 , Humanos , Micelas , PlataRESUMEN
Chemo-photodynamic combination therapy has been received widespread attention in cancer treatment due to its excellent characteristics, such as reducing the adverse side effects of chemo-drugs and improving the therapeutic effects for various cancers. In this study, RGD and DOX was conjugated to PEG by thiol-ene addition and Schiff's base reaction, respectively, to prepare the targeted and pH-sensitive antitumor prodrug nanoparticles (RGD-PEG-DOX NPs, RGD-NPs). Subsequently, the photosensitizer chlorin e6 (Ce6) was encapsulated into RGD-NPs, thus obtaining a simple and efficient chemo-photodynamic combination platform (RGD-PEG-DOX/Ce6 NPs, RGD-NPs/Ce6). This nanoparticle possessed high drug loading property of both the chemo-drug and photosensitizer and could simultaneously release them under the mild acidic microenvironment of cancer cells, which was expected to realize the synchronization therapy of chemotherapy and photodynamic therapy (PDT). Compared with free DOX and Ce6, RGD-NPs/Ce6 could significantly improve the cellular uptake capacities of DOX and Ce6, resulting in the increased contents of ROS in cancer cells and effective cytotoxicity for tumor cells (MDA-MB-231 cells and MCF-7 cells) upon a laser radiation. The in vivo experiment showed that RGD-NPs/Ce6 displayed superior tumor targeting, accumulation, and retention ability than the other groups (free DOX, free Ce6 and NPs/Ce6), and thus significantly enhancing the antitumor effect in vivo with a laser radiation. In addition, the cardiotoxicity induced by DOX was thoroughly wiped out after being loaded and delivered by the nanoparticles according to the pathological analysis. Therefore, the targeted chemo-photodynamic combination therapeutic platform may be a promising candidate for enhanced cancer therapy.
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Nanopartículas , Línea Celular Tumoral , Humanos , Neoplasias , Fotoquimioterapia , Fármacos Fotosensibilizantes , ProfármacosRESUMEN
Finding a smart cancer drug delivery carrier with long blood circulation, enhanced cancer targeting, and quick drug release in tumors is critical for efficient cancer chemotherapy. Herein, we design a cRGD-polycarboxybetaine methacrylate-b-polybenzimidazole methacrylate (cRGD-PCB-b-PBBMZ) copolymer to self-assemble into smart drug-loaded nanoparticles (cRGD-PCM NPs) which can target αvß3 integrin overexpressed cancer tissue by cRGD peptide unit and release drug quickly in cancer cells by protonation of benzimidazole groups. The outer PCB layer can resist protein adhesion, and there are only about 10% of proteins in mouse serum adhered to the surface of PCM NPs. With the pKa value of 5.08 of the benzimidazole units, DOX can be released from NPs in pH 5.0 PBS. cRGD-PCM NPs can bring more DOX into HepG2 cells than nontargeting PCM NPs, and there has high DOX release rate in HepG2 cells because of the protonation of benzimidazole groups in endosome and lysosome. MTT assay verifies that higher cellular uptake of DOX causes higher cytotoxicity. Furthermore, the results of ex vivo imaging studies confirm that cRGD-PCM/DOX NPs can successfully deliver DOX into tumor tissue from the injection site. Therefore, the multifunctional cRGD-PCM NPs show great potential as novel nanocarriers for targeting cancer chemotherapy.
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Neoplasias , Animales , Bencimidazoles , Doxorrubicina , Portadores de Fármacos , Sistemas de Liberación de Medicamentos , Humanos , Concentración de Iones de Hidrógeno , Ratones , NanopartículasRESUMEN
Herein we report on a charge-adaptive nanosystem for prolonged and enhanced in vivo antibiotic delivery. The nanocarrier achieves acid-dependent charge conversion, thus prolonging the circulation time and enhancing antibiotic accumulation in subcutaneous inflammation models.
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Antibacterianos/farmacología , Inflamación/tratamiento farmacológico , Nanoestructuras/química , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/efectos de los fármacos , Vancomicina/farmacología , Animales , Antibacterianos/administración & dosificación , Antibacterianos/química , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos , Concentración de Iones de Hidrógeno , Inyecciones Subcutáneas , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Polímeros/química , Vancomicina/administración & dosificación , Vancomicina/químicaRESUMEN
Ample attention has focused on cancer drug delivery via prodrug nanoparticles due to their high drug loading property and comparatively lower side effects. In this study, we designed a PEG-DOX-Cur prodrug nanoparticle for simultaneous delivery of doxorubicin (DOX) and curcumin (Cur) as a combination therapy to treat cancer. DOX was conjugated to PEG by Schiff's base reaction. The obtained prodrug conjugate could self-assemble in water at pH 7.4 into nanoparticles (PEG-DOX NPs) and encapsulate Cur into the core through hydrophobic interaction (PEG-DOX-Cur NPs). When the PEG-DOX-Cur NPs are internalized by tumor cells, the Schiff's base linker between PEG and DOX would break in the acidic environment that is often observed in tumors, causing disassembling of the PEG-DOX-Cur NPs and releasing both DOX and Cur into the nuclei and cytoplasma of the tumor cells, respectively. Compared with free DOX, free Cur, free DOX-Cur combination, or PEG-DOX NPs, PEG-DOX-Cur NPs exhibited higher anti-tumor activity in vitro. In addition, the PEG-DOX-Cur NPs also showed prolonged blood circulation time, elevated local drug accumulation and increased tumor penetration. Enhanced anti-tumor activity was also observed from the PEG-DOX-Cur-treated animals, demonstrating better tumor inhibitory property of the NPs. Thus, the PEG-DOX-Cur prodrug nanoparticle system provides a simple yet efficient approach of drug delivery for chemotherapy.