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1.
Future Sci OA ; 8(6): FSO807, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35909998

RESUMEN

Aim: To develop an extraction protocol and determine stability for antimicrobial peptide (AMP) Kn2-7 and its d-enantiomer dKn2-7 in human serum. Materials & methods: We compared use of ethanol, acetonitrile, RapiGest SF Surfactant and 1% formic acid in ethanol for AMP recovery from serum prior to liquid chromatography-mass spectrometry quantification. Results: Precipitation of samples with 1% formic acid in ethanol caused the least amount of AMP loss during extraction from serum. Time-course experiments revealed dKn2-7 was significantly more stable than Kn2-7 in 25% serum, with 78.5% of dKn2-7 and only 1.0% of Kn2-7 remaining after 24 h at 37°C. Conclusion: The optimized method significantly increased peptide recovery and allowed more accurate and consistent quantification of Kn2-7 and dKn2-7 serum stability.

2.
Nanomedicine ; 20: 102018, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31125677

RESUMEN

The growing prevalence of biofilm-associated multi-drug resistant (MDR) bacteria necessitates the innovation of non-traditional approaches to improve the effectiveness of mainstay antibiotics. Here, we evaluated the use of gold nanoparticle (GNP)-targeted pulsed laser therapy to enhance antibiotic efficacy against in vitro methicillin-resistant Staphylococcus aureus (MRSA) and MDR Pseudomonas aeruginosa biofilms. Treatment with antibody-conjugated GNPs followed by nanosecond-pulsed laser irradiation at 532 nm (~1.0 J/cm2) dispersed 96-99% of the biofilms relative to controls. GNP-targeted laser therapy combined with gentamicin or amikacin caused a synergistic 4- and 5-log reduction in the viability of MRSA and P. aeruginosa biofilms, respectively, whereas GNP-targeted laser therapy or antibiotics alone decreased biofilm viability by only ~1 log. Notably, GNP-targeted laser therapy was able to increase the antibiotic susceptibility of the biofilms to the level of drug sensitivity observed in planktonic MRSA and P. aeruginosa cultures, further indicating effective biofilm dispersal via this novel approach.


Asunto(s)
Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Terapia por Láser , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Oro/química , Nanopartículas del Metal/química , Pruebas de Sensibilidad Microbiana
3.
Clin Cancer Res ; 24(13): 3176-3185, 2018 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-29602802

RESUMEN

Purpose: Understanding the mechanism of radioresistance could help develop strategies to improve therapeutic response of patients with PDAC. The SMAD4 gene is frequently mutated in pancreatic cancer. In this study, we investigated the role of SMAD4 deficiency in pancreatic cancer cells' response to radiotherapy.Experimental Design: We downregulated SMAD4 expression with SMAD4 siRNA or SMAD4 shRNA and overexpressed SMAD4 in SMAD4 mutant pancreatic cancer cells followed by clonogenic survival assay to evaluate their effects on cell radioresistance. To study the mechanism of radioresistance, the effects of SMAD4 loss on reactive oxygen species (ROS) and autophagy were determined by flow cytometry and immunoblot analysis, respectively. Furthermore, we measured radioresistance by clonogenic survival assay after treatment with autophagy inhibitor (Chloroquine) and ROS inhibitor (N-acetyl-l-cysteine) in SMAD4-depleted pancreatic cancer cells. Finally, the effects of SMAD4 on radioresistance were also confirmed in an orthotopic tumor model derived from SMAD4-depleted Panc-1 cells.Results:SMAD4-depleted pancreatic cancer cells were more resistant to radiotherapy based on clonogenic survival assay. Overexpression of wild-type SMAD4 in SMAD4-mutant cells rescued their radiosensitivity. Radioresistance mediated by SMAD4 depletion was associated with persistently higher levels of ROS and radiation-induced autophagy. Finally, SMAD4 depletion induced in vivo radioresistance in Panc-1-derived orthotopic tumor model (P = 0.038). More interestingly, we observed that the protein level of SMAD4 is inversely correlated with autophagy in orthotopic tumor tissue samples.Conclusions: Our results demonstrate that defective SMAD4 is responsible for radioresistance in pancreatic cancer through induction of ROS and increased level of radiation-induced autophagy. Clin Cancer Res; 24(13); 3176-85. ©2018 AACR.


Asunto(s)
Autofagia/genética , Autofagia/efectos de la radiación , Mutación , Neoplasias Pancreáticas/genética , Tolerancia a Radiación/genética , Proteína Smad4/genética , Animales , Antineoplásicos/farmacología , Apoptosis/genética , Apoptosis/efectos de la radiación , Biomarcadores de Tumor , Línea Celular Tumoral , Proliferación Celular , Supervivencia Celular/genética , Supervivencia Celular/efectos de la radiación , Daño del ADN , Modelos Animales de Enfermedad , Técnicas de Silenciamiento del Gen , Inestabilidad Genómica , Humanos , Inmunohistoquímica , Ratones , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/radioterapia , Especies Reactivas de Oxígeno/metabolismo , Proteína Smad4/metabolismo
4.
Theranostics ; 8(4): 1131-1145, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29464004

RESUMEN

Activation of the vascular endothelium is characterized by increased expression of vascular adhesion molecules and chemokines. This activation occurs early in the progression of several diseases and triggers the recruitment of leukocytes. Inspired by the tropism of leukocytes, we investigated leukocyte-based biomimetic nanoparticles (i.e., leukosomes) as a novel theranostic platform for inflammatory diseases. Methods: Leukosomes were assembled by combining phospholipids and membrane proteins from leukocytes. For imaging applications, phospholipids modified with rhodamine and gadolinium were used. Leukosomes incubated with antibodies blocking lymphocyte function-associated antigen 1 (LFA-1) and CD45 were administered to explore their roles in targeting inflammation. In addition, relaxometric assessment of NPs was evaluated. Results: Liposomes and leukosomes were both spherical in shape with sizes ranging from 140-170 nm. Both NPs successfully integrated 8 and 13 µg of rhodamine and gadolinium, respectively, and demonstrated less than 4% variation in physicochemical features. Leukosomes demonstrated a 16-fold increase in breast tumor accumulation relative to liposomes. Furthermore, quantification of leukosomes in tumor vessels demonstrated a 4.5-fold increase in vessel lumens and a 14-fold increase in vessel walls. Investigating the targeting mechanism of action revealed that blockage of LFA-1 on leukosomes resulted in a 95% decrease in tumor accumulation. Whereas blockage of CD45 yielded a 60% decrease in targeting and significant increases in liver and spleen accumulation. In addition, when administered in mice with atherosclerotic plaques, leukosomes exhibited a 4-fold increase in the targeting of inflammatory vascular lesions. Lastly, relaxometric assessment of NPs demonstrated that the incorporation of membrane proteins into leukosomes did not impact the r1 and r2 relaxivities of the NPs, demonstrating 6 and 30 mM-1s-1, respectively. Conclusion: Our study demonstrates the ability of leukosomes to target activated vasculature and exhibit superior accumulation in tumors and vascular lesions. The versatility of the phospholipid backbone within leukosomes permits the incorporation of various contrast agents. Furthermore, leukosomes can potentially be loaded with therapeutics possessing diverse physical properties and thus warrant further investigation toward the development of powerful theranostic agents.


Asunto(s)
Materiales Biomiméticos/química , Materiales Biomiméticos/farmacocinética , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Endotelio Vascular/metabolismo , Nanopartículas/química , Nanopartículas/metabolismo , Animales , Colorantes Fluorescentes/farmacocinética , Gadolinio/farmacocinética , Leucocitos/química , Leucocitos/metabolismo , Proteínas de la Membrana/aislamiento & purificación , Proteínas de la Membrana/metabolismo , Ratones , Neoplasias/diagnóstico , Neoplasias/tratamiento farmacológico , Fosfolípidos/aislamiento & purificación , Fosfolípidos/metabolismo , Unión Proteica , Rodaminas/farmacocinética , Coloración y Etiquetado/métodos , Nanomedicina Teranóstica/métodos , Enfermedades Vasculares/diagnóstico , Enfermedades Vasculares/tratamiento farmacológico
5.
ACS Nano ; 11(3): 3262-3273, 2017 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-28264157

RESUMEN

Understanding interactions occurring at the interface between nanoparticles and biological components is an urgent challenge in nanomedicine due to their effect on the biological fate of nanoparticles. After the systemic injection of nanoparticles, a protein corona constructed by blood components surrounds the carrier's surface and modulates its pharmacokinetics and biodistribution. Biomimicry-based approaches in nanotechnology attempt to imitate what happens in nature in order to transfer specific natural functionalities to synthetic nanoparticles. Several biomimetic formulations have been developed, showing superior in vivo features as a result of their cell-like identity. We have recently designed biomimetic liposomes, called leukosomes, which recapitulate the ability of leukocytes to target inflamed endothelium and escape clearance by the immune system. To gain insight into the properties of leukosomes, we decided to investigate their protein corona in vivo. So far, most information about the protein corona has been obtained using in vitro experiments, which have been shown to minimally reproduce in vivo phenomena. Here we directly show a time-dependent quantitative and qualitative analysis of the protein corona adsorbed in vivo on leukosomes and control liposomes. We observed that leukosomes absorb fewer proteins than liposomes, and we identified a group of proteins specifically adsorbed on leukosomes. Moreover, we hypothesize that the presence of macrophage receptors on leukosomes' surface neutralizes their protein corona-meditated uptake by immune cells. This work unveils the protein corona of a biomimetic carrier and is one of the few studies on the corona performed in vivo.


Asunto(s)
Nanopartículas/química , Corona de Proteínas/química , Adsorción , Animales , Línea Celular , Microscopía por Crioelectrón , Electroforesis Capilar , Liposomas/sangre , Liposomas/química , Espectrometría de Masas , Ratones , Microscopía Confocal
6.
Infect Drug Resist ; 9: 71-8, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27175088

RESUMEN

Enzymatic debridement is a therapeutic strategy used clinically to remove necrotic tissue from wounds. Some of the enzymes utilized for debridement have been tested against bacterial pathogens, but the effectiveness of these agents in dispersing clinically relevant biofilms has not been fully characterized. Here, we developed an in vitro Staphylococcus aureus biofilm model that mimics wound-like conditions and employed this model to investigate the antibiofilm activity of four enzymatic compounds. Human plasma at concentrations of 0%-50% was supplemented into growth media and used to evaluate biofilm biomass accumulation over 24 hours and 48 hours in one methicillin-sensitive and five methicillin-resistant strains of S. aureus. Supplementation of media with 10% human plasma resulted in the most robust biofilms in all six strains. The enzymes α-amylase, bromelain, lysostaphin, and papain were then tested against S. aureus biofilms cultured in 10% human plasma. Quantification of biofilms after 2 hours and 24 hours of treatment using the crystal violet assay revealed that lysostaphin decreased biomass by up to 76%, whereas α-amylase, bromelain, and papain reduced biomass by up to 97%, 98%, and 98%, respectively. Scanning electron microscopy confirmed that the dispersal agents detached the biofilm exopolysaccharide matrix and bacteria from the growth surface. Lysostaphin caused less visible dispersal of the biofilms, but unlike the other enzymes, induced morphological changes indicative of bacterial cell damage. Overall, our results indicate that use of enzymes may be an effective means of eradicating biofilms and a promising strategy to improve treatment of multidrug-resistant bacterial infections.

7.
Eur J Heart Fail ; 18(2): 169-78, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26749465

RESUMEN

AIMS: Ongoing inflammation and endothelial dysfunction occurs within the local microenvironment of heart failure, creating an appropriate scenario for successful use and delivery of nanovectors. This study sought to investigate whether cardiovascular cells associate, internalize, and traffic a nanoplatform called mesoporous silicon vector (MSV), and determine its intravenous accumulation in cardiac tissue in a murine model of heart failure. METHODS AND RESULTS: In vitro cellular uptake and intracellular trafficking of MSVs was examined by scanning electron microscopy, confocal microscopy, time-lapse microscopy, and flow cytometry in cardiac myocytes, fibroblasts, smooth muscle cells, and endothelial cells. The MSVs were internalized within the first hours, and trafficked to perinuclear regions in all the cell lines. Cytotoxicity was investigated by annexin V and cell cycle assays. No significant evidence of toxicity was found. In vivo intravenous cardiac accumulation of MSVs was examined by high content fluorescence and confocal microscopy, with results showing increased accumulation of particles in failing hearts compared with normal hearts. Similar to observations in vitro, MSVs were able to associate, internalize, and traffic to the perinuclear region of cardiomyocytes in vivo. CONCLUSIONS: Results show that MSVs associate, internalize, and traffic in cardiovascular cells without any significant toxicity. Furthermore, MSVs accumulate in failing myocardium after intravenous administration, reaching intracellular regions of the cardiomyocytes. These findings represent a novel avenue to develop nanotechnology-based therapeutics and diagnostics in heart failure.


Asunto(s)
Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/terapia , Corazón/fisiología , Corazón/fisiopatología , Miocitos Cardíacos/fisiología , Nanoestructuras/uso terapéutico , Animales , Materiales Biocompatibles , Modelos Animales de Enfermedad , Insuficiencia Cardíaca/fisiopatología , Humanos , Inyecciones Intravenosas , Masculino , Ratones , Ratones Endogámicos C57BL , Miocardio , Polímeros , Silicio
8.
J Control Release ; 217: 263-72, 2015 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-26381900

RESUMEN

A key step in particle-based drug delivery throughmicrocirculation is particlemigration from blood flow to vesselwalls, also known as "margination",which promotes particle contact and adhesion to the vesselwall. Margination and adhesion should be independently addressed as two distinct phenomena, considering that the former is a fundamental prerequisite to achieve particle adhesion and subsequent extravasation. Although margination has beenmodeled by numerical simulations and investigated inmodel systems in vitro, experimental studies including red blood cells (RBCs) are lacking. Here, we evaluate the effect of RBCs on margination through microfluidic studies in vitro and by intravital microscopy in vivo.We showthatmargination,which is almost absent when particles are suspended in a cell-free medium, is drastically enhanced by RBCs. This effect is size- and shape-dependent, larger spherical/discoid particles being more effectively marginated both in vitro and in vivo. Our findings can be explained by the collision of particles with RBCs that induces the drifting of the particles towards the vessel walls where they become trapped in the cell-free layer. These results are relevant for the design of drug delivery strategies based on systemically administered carriers.


Asunto(s)
Capilares/fisiología , Eritrocitos/fisiología , Animales , Humanos , Ácido Láctico/química , Ratones Transgénicos , Microcirculación , Microfluídica , Microscopía Confocal , Tamaño de la Partícula , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico
9.
Curr Drug Targets ; 16(6): 528-41, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25901526

RESUMEN

Rapid technical advances in the field of non-linear microscopy have made intravital microscopy a vital pre-clinical tool for research and development of imaging-guided drug delivery systems. The ability to dynamically monitor the fate of macromolecules in live animals provides invaluable information regarding properties of drug carriers (size, charge, and surface coating), physiological, and pathological processes that exist between point-of-injection and the projected of site of delivery, all of which influence delivery and effectiveness of drug delivery systems. In this Review, we highlight how integrating intravital microscopy imaging with experimental designs (in vitro analyses and mathematical modeling) can provide unique information critical in the design of novel disease-relevant drug delivery platforms with improved diagnostic and therapeutic indexes. The Review will provide the reader an overview of the various applications for which intravital microscopy has been used to monitor the delivery of diagnostic and therapeutic agents and discuss some of their potential clinical applications.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Microscopía Intravital/métodos , Animales , Diagnóstico por Imagen/métodos , Humanos , Modelos Teóricos
10.
Adv Healthc Mater ; 4(7): 1092-103, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25721343

RESUMEN

Obstructive biological barriers limit the transport and efficacy of cancer nanotherapeutics. Creative manipulation of tumor microenvironment provides promising avenues towards improving chemotherapeutic response. Such strategies include the use of mechanical stimuli to overcome barriers, and increase drug delivery and therapeutic efficacy. The rational use of gold nanorod-mediated mild hyperthermia treatment (MHT) alters tumor transport properties, increases liposomal gemcitabine (Gem Lip) delivery, and antitumor efficacy in pancreatic cancer CAPAN-1 tumor model. MHT treatment leads to a threefold increase in accumulation of 80-nm liposomes and enhances spatial interstitial distribution. I.v. injection of Gem Lip and MHT treatment lead to a threefold increase in intratumor gemcitabine concentration compared to chemotherapeutic infusion alone. Furthermore, combination of MHT treatment with infusion of 12 mg kg(-1) Gem Lip leads to a twofold increase in therapeutic efficacy and inhibition of CAPAN-1 tumor growth when compared to equimolar chemotherapeutic treatment alone. Enhanced therapeutic effect is confirmed by reduction in tumor size and increase in apoptotic index where MHT treatment combined with 12 mg kg(-1) Gem Lip achieves similar therapeutic efficacy as the use of 60 mg kg(-1) free gemcitabine. In conclusion, improvements in vivo efficacy are demonstrated resulting from MHT treatment that overcome transport barriers, promote delivery, improve efficacy of nanomedicines.


Asunto(s)
Antineoplásicos/administración & dosificación , Desoxicitidina/análogos & derivados , Fiebre/fisiopatología , Liposomas/administración & dosificación , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/terapia , Animales , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Terapia Combinada/métodos , Desoxicitidina/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Oro/administración & dosificación , Hipertermia Inducida/métodos , Ratones , Nanotubos , Neoplasias Pancreáticas/fisiopatología , Gemcitabina
11.
PLoS One ; 9(10): e107973, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25314577

RESUMEN

We report cell mechanical changes in response to alteration of expression of the human equilibrative nucleoside transporter-1 (hENT1), a most abundant and widely distributed plasma membrane nucleoside transporter in human cells and/or tissues. Modulation of hENT1 expression level altered the stiffness of pancreatic cancer Capan-1 and Panc 03.27 cells, which was analyzed by atomic force microscopy (AFM) and correlated to microfluidic platform. The hENT1 knockdown induced reduction of cellular stiffness in both of cells up to 70%. In addition, cellular phenotypic changes such as cell morphology, migration, and expression level of epithelial-mesenchymal transition (EMT) markers were observed after hENT1 knockdown. Cells with suppressed hENT1 became elongated, migrated faster, and had reduced E-cadherin and elevated N-cadherin compared to parental cells which are consistent with epithelial-mesenchymal transition (EMT). Those cellular phenotypic changes closely correlated with changes in cellular stiffness. This study suggests that hENT1 expression level affects cellular phenotype and cell elastic behavior can be a physical biomarker for quantify hENT1 expression and detect phenotypic shift. Furthermore, cell mechanics can be a critical tool in detecting disease progression and response to therapy.


Asunto(s)
Transición Epitelial-Mesenquimal/genética , Tranportador Equilibrativo 1 de Nucleósido/metabolismo , Neoplasias Pancreáticas/fisiopatología , Cadherinas/metabolismo , Línea Celular Tumoral , Movimiento Celular , Separación Celular , Tamaño de la Célula , Tranportador Equilibrativo 1 de Nucleósido/antagonistas & inhibidores , Tranportador Equilibrativo 1 de Nucleósido/genética , Técnicas de Silenciamiento del Gen , Humanos , Técnicas Analíticas Microfluídicas , Microscopía de Fuerza Atómica , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Interferencia de ARN , ARN Interferente Pequeño/metabolismo
12.
Theranostics ; 4(5): 487-97, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24672582

RESUMEN

Effective delivery holds the key to successful in vivo application of therapeutic small interfering RNA (siRNA). In this work, we have developed a universal siRNA carrier consisting of a mesoporous silica nanoparticle (MSNP) functionalized with cyclodextrin-grafted polyethylenimine (CP). CP provides positive charge for loading of siRNA through electrostatic interaction and enables effective endosomal escape of siRNA. Using intravital microscopy we were able to monitor tumor enrichment of CP-MSNP/siRNA particles in live mice bearing orthotopic MDA-MB-231 xenograft tumors. CP-MSNP delivery of siRNA targeting the M2 isoform of the glycolytic enzyme pyruvate kinase (PKM2) resulted in effective knockdown of gene expression in vitro and in vivo. Suppression of PKM2 led to inhibition of tumor cell growth, invasion, and migration.


Asunto(s)
Antineoplásicos/uso terapéutico , Productos Biológicos/uso terapéutico , Portadores de Fármacos/administración & dosificación , Nanopartículas/administración & dosificación , Neoplasias/terapia , ARN Interferente Pequeño/uso terapéutico , Animales , Antineoplásicos/farmacocinética , Antineoplásicos/farmacología , Productos Biológicos/farmacocinética , Productos Biológicos/farmacología , Ciclodextrinas/administración & dosificación , Modelos Animales de Enfermedad , Femenino , Técnicas de Silenciamiento del Gen , Ratones , Polietileneimina/administración & dosificación , Piruvato Quinasa/antagonistas & inhibidores , ARN Interferente Pequeño/farmacocinética , ARN Interferente Pequeño/farmacología , Dióxido de Silicio/administración & dosificación
13.
Sci Rep ; 4: 4502, 2014 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-24675806

RESUMEN

Genetically-modified T cells expressing chimeric antigen receptors (CAR) exert anti-tumor effect by identifying tumor-associated antigen (TAA), independent of major histocompatibility complex. For maximal efficacy and safety of adoptively transferred cells, imaging their biodistribution is critical. This will determine if cells home to the tumor and assist in moderating cell dose. Here, T cells are modified to express CAR. An efficient, non-toxic process with potential for cGMP compliance is developed for loading high cell number with multi-modal (PET-MRI) contrast agents (Super Paramagnetic Iron Oxide Nanoparticles - Copper-64; SPION-(64)Cu). This can now be potentially used for (64)Cu-based whole-body PET to detect T cell accumulation region with high-sensitivity, followed by SPION-based MRI of these regions for high-resolution anatomically correlated images of T cells. CD19-specific-CAR(+)SPION(pos) T cells effectively target in vitro CD19(+) lymphoma.


Asunto(s)
Imagen Molecular/métodos , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Linfocitos T/inmunología , Linfocitos T/metabolismo , Traslado Adoptivo , Antígenos CD19/metabolismo , Supervivencia Celular , Rastreo Celular , Medios de Contraste , Electroporación , Humanos , Imagen por Resonancia Magnética/métodos , Tomografía de Emisión de Positrones/métodos , Unión Proteica , Radiofármacos
14.
PLoS One ; 9(2): e86489, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24558362

RESUMEN

BACKGROUND: Hyperthermia treatment has been explored as a strategy to overcome biological barriers that hinder effective drug delivery in solid tumors. Most studies have used mild hyperthermia treatment (MHT) to target the delivery of thermo-sensitive liposomes carriers. Others have studied its application to permeabilize tumor vessels and improve tumor interstitial transport. However, the role of MHT in altering tumor vessel interfacial and adhesion properties and its relationship to improved delivery has not been established. In the present study, we evaluated effects of MHT treatment on tumor vessel flow dynamics and expression of adhesion molecules and assessed enhancement in particle localization using mesoporous silicon vectors (MSVs). We also determined the optimal time window at which maximal accumulation occur. RESULTS: In this study, using intravital microscopy analyses, we showed that temporal mild hyperthermia (∼1 W/cm(2)) amplified delivery and accumulation of MSVs in orthotopic breast cancer tumors. The number of discoidal MSVs (1000×400 nm) adhering to tumor vasculature increased 6-fold for SUM159 tumors and 3-fold for MCF-7 breast cancer tumors. By flow chamber experiments and Western blotting, we established that a temporal increase in E-selectin expression correlated with enhanced particle accumulation. Furthermore, MHT treatment was shown to increase tumor perfusion in a time-dependent fashion. CONCLUSIONS: Our findings reveal that well-timed mild hyperthermia treatment can transiently elevate tumor transport and alter vascular adhesion properties and thereby provides a means to enhance tumor localization of non-thermally sensitive particles such as MSVs. Such enhancement in accumulation could be leveraged to increase therapeutic efficacy and reduce drug dosing in cancer therapy.


Asunto(s)
Neoplasias de la Mama/irrigación sanguínea , Selectina E/metabolismo , Hipertermia Inducida/métodos , Silicio/química , Animales , Vasos Sanguíneos/metabolismo , Neoplasias de la Mama/terapia , Células Endoteliales/citología , Eritrocitos/citología , Femenino , Humanos , Liposomas/química , Células MCF-7 , Ratones , Ratones Desnudos , Microscopía , Trasplante de Neoplasias , Perfusión
15.
Nanomedicine ; 10(7): 1487-96, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24262998

RESUMEN

The abnormal tumor vasculature presents a major challenge to the adequate delivery of chemotherapeutics, often limiting efficacy. We developed a nanoparticle-based technique to deliver localized mild hyperthermia (MHT) used to transiently alter tumor vascular transport properties and enhance transport of macromolecules into tumor interstitium. The strategy involved administering and localizing accumulation of stealth gold nanorods (GNRs, 103 µg of GNRs/g of tumor), and irradiating tumor with a low-photon laser flux (1 W/cm(2)) to generate MHT. The treatment increased vascular permeability within 24 h after treatment, allowing enhanced transport of macromolecules up to 54 nm in size. A mathematical model is used to describe changes in tumor mass transport properties where the rate of macromolecular exchange between interstitial and vascular region (R) and maximum dye enhancement (Ymax) of 23-nm dextran dye is analytically solved. During enhanced permeability, R increased by 200% while Ymax increased by 30% relative to untreated group in pancreatic CAPAN-1 tumors. MHT treatment also enhanced transport of larger dextran dye (54 nm) as assessed by intravital microscopy, without causing occlusive cellular damage. Enhanced vascular transport was prolonged for up to 24 h after treatment, but reversible with transport parameters returning to basal levels after 36 h. This study indicates that localized mild hyperthermia treatment opens a transient time-window with which to enable and augment macromolecule transport and potentially improve therapeutic efficacy. From the clinical editor: In this study, local intra-tumor mild hyperthermia is induced using a nanoparticle-based approach utilizing stealth gold nanorods and irradiating the tumor with low-photon laser flux, resulting in locally increased vascular permeability enabling enhanced delivery of therapeutics, including macromolecules up to 54 nm in size. Similar approaches would be very helpful in addressing treatment-resistant malignancies in clinical practice.


Asunto(s)
Vasos Sanguíneos/metabolismo , Permeabilidad Capilar , Hipertermia Inducida , Neoplasias Pancreáticas/irrigación sanguínea , Animales , Transporte Biológico , Ratones , Ratones Desnudos , Nanotubos , Neoplasias Pancreáticas/terapia
16.
Nanomedicine ; 9(5): 702-11, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23219875

RESUMEN

We report the use of immuno-targeted gold-iron oxide hybrid nanoparticles for laser-assisted therapy and for MRI-based imaging as demonstrated in xenograft colorectal cancer tumor model. Immuno-targeted gold-iron oxide nanoparticles selectively accumulate in SW1222 xenograft tumors as compared to the accumulation in non-antigen-expressing tumor xenografts. Effective photothermal treatment using near-IR laser irradiation (808nm, 5W cm(-2)) application is shown where >65% of the antigen-expressing tumor cells presented corrupt extracellular matrix and cytoplasmic acidophilia suggesting effectiveness of nanoparticle-assisted thermal therapy. Cell killing was confirmed by hematoxylin and eosin (H&E) histological staining where scar-like structure containing collagen bundles was observed in the treatment group. Further, systemically injected HNPs were shown to be effective T2 magnetic resonance (MR) imaging contrast agents, localized and detected at the antigen-expressing xenograft tumors. These findings suggest that the new class of bio-conjugated HNPs exhibits great potential for dual-therapy and diagnostics (theranostics) applications. FROM THE CLINICAL EDITOR: This team reports the successful use of immuno-targeted gold-iron oxide hybrid nanoparticles for both laser-assisted therapy and MRI-based imaging in a xenograft colorectal cancer tumor model, demonstrating strong potentials for dual applications in cancer diagnosis and therapy.


Asunto(s)
Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/tratamiento farmacológico , Diagnóstico por Imagen , Nanopartículas de Magnetita/administración & dosificación , Animales , Línea Celular Tumoral , Neoplasias Colorrectales/patología , Medios de Contraste/administración & dosificación , Medios de Contraste/química , Compuestos Férricos/administración & dosificación , Compuestos Férricos/química , Oro/administración & dosificación , Oro/química , Humanos , Terapia por Luz de Baja Intensidad , Imagen por Resonancia Magnética/métodos , Nanopartículas de Magnetita/química , Ratones , Ensayos Antitumor por Modelo de Xenoinjerto
17.
Biomicrofluidics ; 6(4): 44119, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-24348890

RESUMEN

The present work describes the operation and simulation of a microfluidic laminar-flow mixer. Diffusive mixing takes place between a core solution containing lipids in ethanol and a sheath solution containing aqueous buffer, leading to self assembly of liposomes. Present device architecture hydrodynamically focuses the lipid solution into a cylindrical core positioned at the center of a microfluidic channel of 125 × 125-µm(2) cross-section. Use of the device produces liposomes in the size range of 100-300 nm, with larger liposomes forming at greater ionic strength in the sheath solution and at lower lipid concentration in the core solution. Finite element simulations compute the concentration distributions of solutes at axial distances of greater than 100 channel widths. These simulations reduce computation time and enable computation at long axial distances by utilizing long hexahedral elements in the axial flow region and fine tetrahedral elements in the hydrodynamic focusing region. Present meshing technique is generally useful for simulation of long microfluidic channels and is fully implementable using comsol Multiphysics. Confocal microscopy provides experimental validation of the simulations using fluorescent solutions containing fluorescein or enhanced green fluorescent protein.

18.
Macromol Biosci ; 11(6): 779-88, 2011 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-21438153

RESUMEN

A single-step LbL procedure to functionalize CTAB-capped GNRs via electrostatic self-assembly is reported. This approach allows for consistent biomolecule/GNR coupling using standard carboxyl-amine conjugation chemistry. The focus is on cancer-targeting biomolecule/GNR conjugates and selective photothermal destruction of cancer cells by GNR-mediated hyperthermia and NIR light. GNRs were conjugated to a single-chain antibody selective for colorectal carcinoma cells and used as probes to demonstrate photothermal therapy. Selective targeting and GNR uptake in antigen-expressing SW 1222 cells were observed using fluorescence microscopy. Selective photothermal therapy is demonstrated using SW 1222 cells, where >62% cell death was observed after cells are treated with targeted A33scFv-GNRs.


Asunto(s)
Neoplasias Colorrectales/tratamiento farmacológico , Inmunoconjugados/farmacología , Terapia Molecular Dirigida/métodos , Fototerapia/métodos , Anticuerpos de Cadena Única/farmacología , Resinas Acrílicas/química , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Cetrimonio , Compuestos de Cetrimonio/química , Neoplasias Colorrectales/patología , Fluoresceína-5-Isotiocianato/análisis , Oro/química , Calor/uso terapéutico , Humanos , Inmunoconjugados/química , Inmunoconjugados/metabolismo , Rayos Infrarrojos/uso terapéutico , Nanotubos/química , Tamaño de la Partícula , Fototerapia/instrumentación , Anticuerpos de Cadena Única/química , Anticuerpos de Cadena Única/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Tensoactivos/química
19.
ACS Appl Mater Interfaces ; 2(7): 1804-10, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20565131

RESUMEN

Polyhydroxyalkanoate (PHA) synthase attached to gold nanoparticles (AuNP) produce poly(3-hydroxybutyrate) (PHB) upon the addition of 3-hydroxybutyrate-CoA, and then coalesce to form micrometer-sized AuNP-coated PHB granules. These AuNP-coated PHB granules are potential theranostic agents that have enhanced imaging capabilities and are capable of heating upon near-infrared laser irradiation. The AuNP-coated PHB exhibited 11-fold enhancement in surface-enhanced Raman scattering over particles prior polymerization. Stained AuNP-coated PHB exhibited a 6-fold enhancement in fluorescence intensity as well as a 1.3-fold decrease in photobleaching rate compared to PHB granules alone. The granules were also shown to emit heat when illuminated at 808 nm with a 3.9-fold increase in heating rate compared to particles alone.


Asunto(s)
Fluorescencia , Oro/química , Hidroxibutiratos/química , Nanopartículas del Metal/química , Poliésteres/química , Calor , Rayos Láser , Óptica y Fotónica/métodos , Tamaño de la Partícula , Propiedades de Superficie
20.
Nanotechnology ; 21(10): 105105, 2010 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-20154383

RESUMEN

Gold and iron oxide hybrid nanoparticles (HNPs) synthesized by the thermal decomposition technique are bio-functionalized with a single chain antibody, scFv, that binds to the A33 antigen present on colorectal cancer cells. The HNP-scFv conjugates are stable in aqueous solution with a magnetization value of 44 emu g(-1) and exhibit strong optical absorbance at 800 nm. Here we test this material in targeting, imaging and selective thermal killing of colorectal cancer cells. Cellular uptake studies showed that A33-expressing cells take up the A33scFv-conjugated HNPs at a rate five times higher than cells that do not express the A33 antigen. Laser irradiation studies showed that approximately 53% of the A33-expressing cells exposed to targeted HNPs are killed after a six-minute laser treatment at 5.1 W cm(-2) using a 808 nm continuous wave laser diode while < 5% of A33-nonexpressing cells are killed. At a higher intensity, 31.5 W cm(-2), the thermal destruction increases to 99 and 40% for A33-expressing cells and A33 nonexpressing cells, respectively, after 6 min exposure. Flow cytometric analyses of the laser-irradiated A33 antigen-expressing cells show apoptosis-related cell death to be the primary mode of cell death at 5.1 W cm(-2), with increasing necrosis-related cell death at higher laser power. These results suggest that this new class of bio-conjugated hybrid nanoparticles can potentially serve as an effective antigen-targeted photothermal therapeutic agent for cancer treatment as well as a probe for magnetic resonance-based imaging.


Asunto(s)
Compuestos Férricos/química , Oro/química , Nanopartículas/química , Neoplasias/patología , Fototerapia/métodos , Anticuerpos de Cadena Única/química , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Células HT29 , Humanos , Glicoproteínas de Membrana/metabolismo , Nanopartículas/efectos adversos , Neoplasias/terapia
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