RESUMEN
Despite large unmet medical needs in the field for several decades, CNS drug discovery and development has been largely unsuccessful. Biomarkers, particularly those utilizing neuroimaging, have played important roles in aiding CNS drug development, including dosing determination of investigational new drugs (INDs). A recent working group was organized jointly by CINP and Japanese Society of Neuropsychopharmacology (JSNP) to discuss the utility of biomarkers as tools to overcome issues of CNS drug development.The consensus statement from the working group aimed at creating more nuanced criteria for employing biomarkers as tools to overcome issues surrounding CNS drug development. To accomplish this, a reverse engineering approach was adopted, in which criteria for the utilization of biomarkers were created in response to current challenges in the processes of drug discovery and development for CNS disorders. Based on this analysis, we propose a new paradigm containing 5 distinct tiers to further clarify the use of biomarkers and establish new strategies for decision-making in the context of CNS drug development. Specifically, we discuss more rational ways to incorporate biomarker data to determine optimal dosing for INDs with novel mechanisms and targets, and propose additional categorization criteria to further the use of biomarkers in patient stratification and clinical efficacy prediction. Finally, we propose validation and development of new neuroimaging biomarkers through public-private partnerships to further facilitate drug discovery and development for CNS disorders.
Asunto(s)
Biomarcadores , Fármacos del Sistema Nervioso Central , Descubrimiento de Drogas/métodos , Neuroimagen , Neurofarmacología/métodos , Psicofarmacología/métodos , Descubrimiento de Drogas/normas , Humanos , Neurofarmacología/normas , Psicofarmacología/normasRESUMEN
Near infrared photoimmunotherapy (NIR-PIT) is a new cancer treatment that combines the specificity of antibodies for targeting tumors with the toxicity induced by photosensitizers after exposure to near infrared (NIR) light. Herein we compare two NIR-light sources; light emitting diodes (LEDs) and Lasers, for their effectiveness in NIR-PIT. A photosensitizer, IRDye-700DX, conjugated to panitumumab (pan-IR700), was incubated with EGFR-expressing A431 and MDA-MB-468-luc cells. NIR-light was provided by LEDs or Lasers at the same light dose. Laser-light produced more cytotoxicity and greater reductions in IR700-fluorescence intensity than LED-light. Laser-light also produced more cytotoxicity in vivo in both cell lines. Assessment of super-enhanced permeability and retention (SUPR) effects were stronger with Laser than LED. These results suggest that Laser-light produced significantly more cytotoxic effects compared to LEDs. Although LED is less expensive, Laser-light produces superior results in NIR-PIT.
Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Neoplasias de la Mama/terapia , Inmunoterapia , Rayos Láser , Neoplasias Pulmonares/terapia , Fotoquimioterapia , Fármacos Fotosensibilizantes/uso terapéutico , Animales , Apoptosis , Neoplasias de la Mama/inmunología , Neoplasias de la Mama/patología , Proliferación Celular , Terapia Combinada , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/inmunología , Femenino , Humanos , Rayos Infrarrojos , Luz , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/patología , Ratones , Ratones Desnudos , Panitumumab , Fototerapia , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
A novel approach for ultrasound (US) mediated drug delivery - Acoustic Cluster Therapy (ACT) - is proposed, and basic characteristics of the ACT formulation are elucidated. The concept comprises administration of free flowing clusters of negatively charged microbubbles and positively charged microdroplets. The clusters are activated within the target pathology by diagnostic US, undergo an ensuing liquid-to-gas phase shift and transiently deposit 20-30 µm large bubbles in the microvasculature, occluding blood flow for â¼5-10 min. Further application of US will induce biomechanical effects that increases the vascular permeability, leading to a locally enhanced extravasation of components from the vascular compartment (e.g. released or co-administered drugs). Methodologies are detailed for determination of vital in-vitro characteristics of the ACT compound; cluster concentration and size distribution. It is shown how these attributes can be engineered through various formulation parameters, and their significance as predictors of biological behaviour, such as deposit characteristics, is demonstrated by US imaging in a dog model. Furthermore, in-vivo properties of the activated ACT bubbles are studied by intravital microscopy in a rat model, confirming the postulated behaviour of the concept.
Asunto(s)
Acústica , Sistemas de Liberación de Medicamentos/métodos , Microburbujas , Ultrasonido , Animales , Permeabilidad Capilar/fisiología , Perros , Corazón/fisiología , Transición de Fase , Ratas , Circulación Esplácnica/fisiologíaRESUMEN
PURPOSE: CS-1008 (tigatuzumab) is a humanized, monoclonal immunoglobulin G1 (IgG1) agonistic antibody to human death receptor 5. The purpose of this study was to investigate the impact of CS-1008 dose on the biodistribution, quantitative tumor uptake, and antitumor response in patients with metastatic colorectal cancer (mCRC). PATIENTS AND METHODS: Patients with mCRC who had received at least one course of chemotherapy were assigned to one of five dosage cohorts and infused with a weekly dose of CS-1008. Day 1 and day 36 doses were trace-labeled with indium-111 ((111)In), followed by whole-body planar and regional single-photon emission computed tomography (SPECT) imaging at several time points over the course of 10 days. RESULTS: Nineteen patients were enrolled. (111)In-CS-1008 uptake in tumor was observed in only 12 patients (63%). (111)In-CS-1008 uptake and pharmacokinetics were not affected by dose or repeated drug administration. (111)In-CS-1008 biodistribution showed gradual blood-pool clearance and no abnormal uptake in normal tissue. No anti-CS-1008 antibody development was detected. One patient achieved partial response (3.7 months duration), eight patients had stable disease, and 10 patients had progressive disease. Clinical benefit rate (stable disease + partial response) in patients with (111)In-CS-1008 uptake in tumor was 58% versus 28% in patients with no uptake. An analysis of individual lesions showed that lesions with antibody uptake were one third as likely to progress as those without antibody uptake (P = .07). Death-receptor-5 expression in archived tumor samples did not correlate with (111)In-CS-1008 uptake (P = .5) or tumor response (P = .6). CONCLUSION: Death-receptor-5 imaging with (111)In-CS-1008 reveals interpatient and intrapatient heterogeneity of uptake in tumor, is not dose dependent, and is predictive of clinical benefit in the treatment of patients who have mCRC.
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Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/farmacocinética , Neoplasias Colorrectales/diagnóstico por imagen , Neoplasias Colorrectales/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Radioisótopos de Indio , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Cintigrafía , Radiofármacos/administración & dosificación , Radiofármacos/farmacocinética , Distribución TisularRESUMEN
To investigate the feasibility of contrast-enhanced ultrasound (CEUS) with perflubutane for evaluating anti-angiogenic effects, we assessed the contrast enhancement of mice xenograft treated with bevacizumab. SJSA-1 implanted mice were imaged before and 2, 6, 9 and 13 d after initiation of bevacizumab or saline treatment. Intra-tumoral perfusion areas were quantified by binarizing the ultrasound images and the micro-vessel density was observed by CD31 immunohistochemistry. As a result, the perfusion area and its ratio in the tumor were smaller in the bevacizumab group than the control group at 9 and 13 d, although tumor size was not significantly different. CD31-positive areas were smaller in the bevacizumab group than the control group and correlated well with the ratio of intra-tumoral perfusion areas. CEUS with perflubutane was found to have potential for early prediction of the anti-cancer activity of bevacizumab, and the perfusion area measured by binarized ultrasound images could be used as an indicator.
Asunto(s)
Bevacizumab/uso terapéutico , Detección Precoz del Cáncer/métodos , Neoplasias Experimentales/diagnóstico por imagen , Neoplasias Experimentales/tratamiento farmacológico , Neovascularización Patológica/diagnóstico por imagen , Neovascularización Patológica/tratamiento farmacológico , Inhibidores de la Angiogénesis/uso terapéutico , Animales , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Medios de Contraste , Estudios de Factibilidad , Fluorocarburos , Humanos , Aumento de la Imagen/métodos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Desnudos , Pronóstico , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Resultado del Tratamiento , Ultrasonografía/métodosRESUMEN
Glypican-3 (GPC3) represents an attractive target for hepatocellular carcinoma (HCC) therapy because it is highly expressed in HCC but not in adult normal tissue. Recently, high affinity anti-GPC3 antibodies have been developed; however, full antibodies may not penetrate evenly into tumor parenchyma, reducing their effectiveness. In this study, we compared a whole IgG antibody, anti-GPC3 YP7, with an anti-GPC3 human heavy chain antibody, HN3, with regard to their relative therapeutic effects. Both YP7 and HN3 bound to GPC3-positive A431/G1 cells and were internalized by the cells by in vitro evaluation with (125)I- and (111)In-radiolabeling antibodies. In vivo biodistribution and tumor accumulation was performed with (111)In-labeled antibodies, and intratumoral microdistribution was evaluated using fluorescently labeled antibodies (IR700). HN3 showed similar high tumor accumulation but superior homogeneity within the tumor compared with YP7. Using the same IR700 conjugated antibodies photoimmunotherapy (PIT) was performed in vitro and in a tumor-bearing mouse model in vivo. PIT with IR700-HN3 and IR700-YP7 demonstrated that comparable results could be achieved despite of low reaccumulation 24 h after the first NIR light exposure. These results indicated that a heavy-chain antibody, HN3, showed more favorable characteristics than YP7, a conventional IgG, as a therapeutic antibody platform for designing molecularly targeted agents against HCC.
Asunto(s)
Carcinoma Hepatocelular/tratamiento farmacológico , Glipicanos/inmunología , Cadenas Pesadas de Inmunoglobulina/uso terapéutico , Neoplasias Hepáticas/terapia , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/uso terapéutico , Carcinoma Hepatocelular/inmunología , Línea Celular Tumoral , Portadores de Fármacos/química , Femenino , Humanos , Cadenas Pesadas de Inmunoglobulina/inmunología , Inmunoterapia , Neoplasias Hepáticas/inmunología , RatonesRESUMEN
AIM: Effectiveness of Glypican-3 (GPC3)-targeted photoimmunotherapy (PIT) combined with the nanoparticle albumin-bound paclitaxel (nab-paclitaxel) for hepatocellular carcinoma was evaluated. MATERIALS & METHODS: GPC3 expressing A431/G1 cells were incubated with a phthalocyanine-derivative, IRDye700DX (IR700), conjugated to an anti-GPC3 antibody, IR700-YP7 and exposed to near-infrared light. Therapeutic experiments combining GPC3-targeted PIT with nab-paclitaxel were performed in A431/G1 tumor-bearing mice. RESULTS: IR700-YP7 bound to A431/G1 cells and induced rapid target-specific necrotic cell death by near-infrared light exposure in vitro. IR700-YP7 accumulated in A431/G1 tumors. Tumor growth was inhibited by PIT compared with nontreated control. Additionally, PIT dramatically increased nab-paclitaxel delivery and enhanced the therapeutic effect. CONCLUSION: PIT targeting GPC3 combined with nab-paclitaxel is a promising method for treating hepatocellular carcinoma.
Asunto(s)
Albúminas/uso terapéutico , Antineoplásicos/uso terapéutico , Carcinoma Hepatocelular/terapia , Glipicanos/inmunología , Inmunoterapia , Neoplasias Hepáticas/terapia , Paclitaxel/uso terapéutico , Fototerapia , Animales , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/inmunología , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Femenino , Inmunoterapia/métodos , Hígado/efectos de los fármacos , Hígado/inmunología , Hígado/patología , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/inmunología , Neoplasias Hepáticas/patología , Ratones , Ratones Desnudos , Fototerapia/métodosRESUMEN
Near infrared photoimmunotherapy (NIR-PIT) is a new cancer treatment that combines the specificity of intravenously injected antibodies for targeting tumors with the toxicity induced by photosensitizers after exposure to near infrared (NIR) light. Herein, we evaluate the efficacy of NIR-PIT in a mouse model of disseminated peritoneal ovarian cancer. In vitro and in vivo experiments were conducted with a HER2-expressing, luciferase-expressing, ovarian cancer cell line (SKOV-luc). An antibody-photosensitizer conjugate (APC) consisting of trastuzumab and a phthalocyanine dye, IRDye-700DX, was synthesized (tra-IR700) and cells or tumors were exposed to NIR light. In vitro PIT cytotoxicity was assessed with dead staining and luciferase activity in freely growing cells and in a three-dimensional (3D) spheroid model. In vivo NIR-PIT was performed in mice with tumors implanted in the peritoneum and in the flank and these were assessed by tumor volume and/or bioluminescence. In vitro NIR-PIT-induced cytotoxicity was light dose dependent. Repeated light exposures induced complete tumor cell killing in the 3D spheroid model. In vivo the antitumor effects of NIR-PIT were confirmed by significant reductions in both tumor volume and luciferase activity in the flank model (NIR-PIT vs. control in tumor volume changes at day 10, P = 0.0001; NIR-PIT vs. control in luciferase activity at day 4, P = 0.0237), and the peritoneal model (NIR-PIT vs. control in luciferase activity at day 7, P = 0.0037). NIR-PIT provided effective cell killing in this HER2-positive model of disseminated peritoneal ovarian cancer. Thus, NIR-PIT is a promising new therapy for the treatment of disseminated peritoneal tumors.
Asunto(s)
Anticuerpos Monoclonales Humanizados/química , Inmunoconjugados/administración & dosificación , Indoles/química , Rayos Infrarrojos/uso terapéutico , Neoplasias Ováricas/terapia , Neoplasias Peritoneales/terapia , Fármacos Sensibilizantes a Radiaciones/química , Animales , Línea Celular Tumoral , Relación Dosis-Respuesta en la Radiación , Femenino , Humanos , Inmunoconjugados/química , Inmunoglobulinas Intravenosas/administración & dosificación , Inmunoglobulinas Intravenosas/química , Inmunoterapia/métodos , Isoindoles , Ratones , Ratones Desnudos , Trasplante de Neoplasias , TrastuzumabRESUMEN
UNLABELLED: Photoimmunotherapy is a highly cell-selective cancer therapy based on an armed antibody conjugate with a phthalocyanine-based photosensitizer, IR700. Photoimmunotherapy induces rapid and highly specific necrosis in targeted cancer cells after exposure to near-infrared (NIR) light. Cells not expressing the antigen are not affected. To date, photoimmunotherapy has been demonstrated only with full antibody-IR700 conjugates. In this study, small and bivalent antibody fragments, including anti-prostate-specific membrane antigen (PSMA) diabody (Db) and minibody (Mb), were compared with intact IgG for their effectiveness as photoimmunotherapy agents. METHODS: Radioiodinated antibody and antibody fragments with (125)I were used to determine the timing of maximum binding of each anti-PSMA antibody fragment on the cell surface in vivo in mice bearing either PSMA-positive or -negative PC3 tumors. Then therapeutic efficacy of photoimmunotherapy was examined by exposing mice to NIR light at 2 time points based on the time of maximum cell surface binding at 6 h after injection for Db-IR700 and 24 h after injection for Mb-IR700 and IgG-IR700 as well as 24 h after the peak uptake times. RESULTS: Photoimmunotherapy with the same molar concentration of PSMA-Db-IR700, PSMA-Mb-IR700, and PSMA-IgG-IR700 conjugate showed similar therapeutic effects in vitro and in vivo on PSMA-positive PC3 tumor xenografts in cytotoxicity and survival curves (P > 0.05). CONCLUSION: The use of PSMA-Db-IR700 conjugate results in the shortest time interval between injection and NIR exposure without compromising therapeutic effects of photoimmunotherapy.
Asunto(s)
Antígenos de Superficie/inmunología , Glutamato Carboxipeptidasa II/inmunología , Fragmentos de Inmunoglobulinas/inmunología , Fragmentos de Inmunoglobulinas/uso terapéutico , Inmunoterapia/métodos , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Proliferación Celular/efectos de la radiación , Femenino , Humanos , Inmunoconjugados/uso terapéutico , Fragmentos de Inmunoglobulinas/química , Indoles/química , Indoles/farmacología , Rayos Infrarrojos , Isoindoles , Masculino , Ratones , Necrosis/inducido químicamente , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacología , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/terapia , Distribución TisularRESUMEN
In order to efficiently deliver anticancer agents to tumors, biocompatible nanoparticles or bioconjugates, including antibody-drug conjugates (ADCs), have recently been designed, synthesized, and tested, some even in clinical trials. Controlled delivery can be enhanced by changing specific design characteristics of the bioconjugate such as its size, the nature of the payload, and the surface features. The delivery of macromolecular drugs to cancers largely relies on the leaky nature of the tumor vasculature compared with healthy vessels in normal organs. When administered intravenously, macromolecular bioconjugates and nanosized agents tend to circulate for prolonged times, unless they are small enough to be excreted by the kidney or stealthy enough to evade the macrophage phagocytic system (MPS), formerly the reticulo-endothelial system (RES). Therefore, macromolecular bioconjugates and nanosized agents with long circulation times leak preferentially into tumor tissue through permeable tumor vessels and are then retained in the tumor bed due to reduced lymphatic drainage. This process is known as the enhanced permeability and retention (EPR) effect. However, success of cancer drug delivery only relying on the EPR effect is still limited. To cure cancer patients, further improvement of drug delivery is required by both designing superior agents and enhancing EPR effects. In this Review, we describe the basis of macromolecular or nanosized bioconjugate delivery into cancer tissue and discuss current diagnostic methods for evaluating leakiness of the tumor vasculature. Then, we discuss methods to augment conventional "permeability and retention" effects for macromolecular or nanosized bioconjugates in cancer tissue.
Asunto(s)
Antineoplásicos/administración & dosificación , Antineoplásicos/química , Sistemas de Liberación de Medicamentos/métodos , Nanoestructuras/química , Animales , Antineoplásicos/farmacocinética , Humanos , Nanoestructuras/administración & dosificación , Neoplasias/irrigación sanguínea , Neoplasias/tratamiento farmacológicoRESUMEN
Photoimmunotherapy (PIT) is a cell-specific cancer therapy based on an armed antibody conjugate that induces rapid and highly selective cancer cell necrosis after exposure to near-infrared (NIR) light. The PIT treatment also induces the superenhanced permeability and retention effect, which allows high concentrations of nanoparticles to accumulate in the tumor bed. In our pilot studies, optical coherence tomography (OCT) reveals dramatic hemodynamic changes during PIT. We developed and applied speckle variance analysis, Doppler flow measurement, bulk motion removal, and automatic region of interest selection to quantify vessel diameter and blood velocity within tumors in vivo. OCT imaging reveals that blood velocity in peripheral tumor vessels quickly drops below the detection limit while the vessel lumen remains open (4 vessels from 3 animals). On the other hand, control tumor vessels (receive NIR illumination but no PIT drug) do not show the sustained blood velocity drop (5 vessels from 3 animals). Ultraslow blood velocity could result in a long drug circulation time in tumor. Increase of the blood pool volume within the central tumor (shown in histology) may be the leading cause of the periphery blood velocity drop and could also increase the drug pool volume in tumor vessels.
Asunto(s)
Hemodinámica/fisiología , Neoplasias/irrigación sanguínea , Neoplasias/terapia , Tomografía de Coherencia Óptica/métodos , Animales , Femenino , Inmunoterapia , Ratones , Ratones Desnudos , Neoplasias/patología , Neoplasias/fisiopatología , Fantasmas de Imagen , Fototerapia , Microambiente TumoralRESUMEN
BACKGROUND: Photoimmunotherapy (PIT) is a highly cell-selective cancer therapy, which employs monoclonal antibodies conjugated to a potent photosensitizer (mAb-IR700). Once the conjugate has bound to the target cell, exposure to near infrared (NIR) light induces necrosis only in targeted cells with minimal damage to adjacent normal cells in vivo. Herein, we report on the effect of altering mAb-IR700 and light power and dose on effectiveness of PIT. METHODS: For evaluating cytotoxicity, we employed ATP-dependent bioluminescence imaging using a luciferase-transfected MDA-MB-468luc cell line, which expresses EGFR and luciferase. In in vitro experiments, panitumumab-IR700 (Pan-IR700) concentration was varied in combination with varying NIR light doses administered by an LED at one of three power settings, 100 mA and 400 mA continuous wave and 1733 mA intermittent wave. For in vivo experiments, the MDA-MB-468luc orthotopic breast cancer was treated with varying doses of Pan-IR700 and light. RESULTS: The in vitro cell study demonstrated that PIT induced cytotoxicity depended on light dose, when the conjugate concentration was kept constant. Increasing the dose of Pan-IR700 allowed lowering of the light dose to achieve equal effects thus indicating that for a given level of efficacy, the conjugate concentration multiplied by the light dose was a constant. A similar relationship between conjugate and light dose was observed in vivo. CONCLUSIONS: The efficacy of PIT is defined by the product of the number of bound antibody conjugates and the dose of NIR light and can be achieve equally with continuous and pulse wave LED light using different power densities.
Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Inmunoterapia/efectos adversos , Fármacos Fotosensibilizantes/administración & dosificación , Fototerapia/efectos adversos , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias de la Mama/inmunología , Neoplasias de la Mama/patología , Línea Celular Tumoral , Receptores ErbB/biosíntesis , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Panitumumab , Fármacos Fotosensibilizantes/efectos adversosRESUMEN
Minibodies show rapider blood clearance than IgGs due to smaller size that improves target-to-background ratio (TBR) in in vivo imaging. Additionally, the ability to activate an optical probe after binding to the target greatly improves the TBR. An optical imaging probe based on a minibody against prostate-specific membrane antigen (PSMA-MB) and conjugated with an activatable fluorophore, indocyanine green (ICG), was designed to fluoresce only after binding to cell-surface PSMA. To further reduce background signal, short polyethylene glycol (PEG) linkers were employed to improve the covalent bonding ratio of ICG. New PSMA-MBs conjugated with bifunctional ICG derivatives specifically visualized PSMA-positive tumor xenografts in mice bearing both PSMA-positive and -negative tumors within 6 h postinjection. The addition of short PEG linkers significantly improved TBRs; however, it did not significantly alter the biodistribution. Thus, minibody-ICG conjugates could be a good alternative to IgG-ICG in the optical cancer imaging for further clinical applications.
RESUMEN
Photoimmunotherapy (PIT) is a new cancer treatment that combines the specificity of antibodies for targeting tumors with the toxicity induced by photosensitizers after exposure to near infrared (NIR) light. Herein we compare two commonly available anti-EGFR monoclonal antibodies, cetuximab and panitumumab, for their effectiveness as PIT agents in EGFR positive tumor models. A photosensitizer, IR-700, conjugated to either cetuximab (cet-IR700) or panitumumab (pan-IR700), was evaluated using EGFR-expressing A431 and MDAMB468-luc cells in 2D- and 3D-culture. PIT was conducted with irradiation of NIR light after exposure of the sample or animal to each conjugate. In vivo PIT was performed with fractionated exposure of NIR light after injection of each agent into A431 xenografts or a MDAMB468-luc orthotopic tumor bearing model. Cet-IR700 and pan-IR700 bound with equal affinity to the cells in 2D-culture and penetrated equally into the 3D-spheroid, resulting in identical PIT cytotoxic effects in vitro. In contrast, in vivo anti-tumor effects of PIT with cet-IR700 were inferior to that of pan-IR700. Assessment of the biodistribution showed lower accumulation into the tumors and more rapid hepatic catabolism of cet-IR700 compared to pan-IR700. Although cet-IR700 and pan-IR700 showed identical in vitro characteristics, pan-IR700 showed better therapeutic tumor responses than cet-IR700 in in vivo mice models due to the prolonged retention of the conjugate in the circulation, suggesting that retention in the circulation is advantageous for tumor responses to PIT. These results suggest that the choice of monoclonal antibody in photosensitizer conjugates may influence the effectiveness of PIT.
Asunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales/uso terapéutico , Receptores ErbB/antagonistas & inhibidores , Inmunoterapia/métodos , Neoplasias/terapia , Fármacos Fotosensibilizantes/uso terapéutico , Fototerapia/métodos , Animales , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/farmacocinética , Anticuerpos Monoclonales Humanizados/química , Anticuerpos Monoclonales Humanizados/farmacocinética , Línea Celular Tumoral , Cetuximab , Femenino , Humanos , Ratones , Neoplasias/patología , Panitumumab , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacocinética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Blood contamination, such as bloody ascites or hemorrhages during surgery, is a potential hazard for clinical application of fluorescence imaging. In order to overcome this problem, we investigate if fluorescence-lifetime imaging helps to overcome this problem. Samples were prepared at concentrations ranging 0.3-2.4 µm and mixed with 0-10% of blood. Fluorescence intensities and lifetimes of samples were measured using a time-domain fluorescence imager. Ovarian cancer SHIN3 cells overexpressing the D-galactose receptor were injected into the peritoneal cavity 2.5 weeks before the experiments. Galactosyl serum albumin-rhodamine green (GSA-RhodG), which bound to the D-galactose receptor and was internalized thereafter, was administered intraperitoneally to peritoneal ovarian cancer-bearing mice with various degrees of bloody ascites. In vitro study showed a linear correlation between fluorescence intensity and probe concentration (r(2) > 0.99), whereas the fluorescence lifetime was consistent (range, 3.33 ± 0.15-3.75 ± 0.04 ns). By adding 10% of blood to samples, fluorescence intensities decreased to <1%, while fluorescence lifetimes were consistent. In vivo fluorescence lifetime of GSA-RhodG stained tumors was longer than the autofluorescence lifetime (threshold, 2.87 ns). Tumor lesions under hemorrhagic peritonitis were not depicted using fluorescence intensity imaging; however, fluorescence-lifetime imaging clearly detected tumor lesions by prolonged lifetimes. In conclusion, fluorescence-lifetime imaging with GSA-RhodG depicted ovarian cancer lesions, which were invisible in intensity images, in hemorrhagic ascites.
Asunto(s)
Ascitis/patología , Pérdida de Sangre Quirúrgica , Neoplasias Ováricas/patología , Neoplasias Peritoneales/secundario , Albúminas , Animales , Línea Celular Tumoral , Femenino , Colorantes Fluorescentes , Humanos , Ratones , Ratones Desnudos , Imagen Molecular , Trasplante de Neoplasias , Imagen Óptica , Peritoneo/cirugía , Rodaminas , Imagen de Cuerpo EnteroRESUMEN
Near infrared (NIR) fluorescent probes are ideal for in vivo imaging because they offer deeper tissue penetration and lower background autofluorescence. Although most fluorophores in this range are cyanine-based dyes, several new classes of fluorescent NIR probes have been developed. In this study, we developed organic bacteriochlorin derivatives, NMP4 and NMP5, which are excited with a single green light and emit different narrow, well-resolved bands in the NIR (peak of 739 and 770 nm for NMP4 and NMP5, respectively). When conjugated to galactosyl-human serum albumin (hGSA) or glucosyl-human serum albumin (glu-HSA), both targeting H-type lectins, including the ß-d-galactose receptor expressing on ovarian cancer, these agents become targeted, activatable, single excitation, multicolor NIR fluorescence probes. After conjugation to either glu-HSA or hGSA, substantial quenching of fluorescence occurs that is reversed after cell binding and internalization. In vitro studies showed higher cancer cell uptake with NMP4 or NMP5 conjugated to hGSA compared to the same conjugates with glu-HSA. In vivo single excitation two-color imaging was performed after intraperitoneal injection of these agents into mice with disseminated ovarian cancer. Excited with a single green light, distinct NIR emission spectra from each fluorophore were detected and could be distinguished with spectral unmixing. In vivo results using a red fluorescence protein (RFP) labeled tumor model of disseminated ovarian cancer demonstrated high sensitivity and specificity for all probes. The success of single excitation, 2-color NIR fluorescence imaging with a new class of bacteriochlorin-based activatable fluorophores, NMP4 and NMP5, paves the way for further exploration of noncyanine dye-based NIR fluorophores.
Asunto(s)
Colorantes Fluorescentes/química , Porfirinas/química , Línea Celular Tumoral , Femenino , Humanos , Espectroscopía de Resonancia Magnética , Espectrometría de Masa por Ionización de Electrospray , Espectroscopía Infrarroja CortaRESUMEN
Nano-sized therapeutic agents have several advantages over low molecular weight agents such as a larger loading capacity, the ability to protect the payload until delivery, more specific targeting due to multivalency and the opportunity for controlled/sustained release. However, the delivery of nano-sized agents into cancer tissue is problematic because it mostly relies on the enhanced permeability and retention (EPR) effect that depends on the leaky nature of the tumor vasculature and the prolonged circulation of nano-sized agents, allowing slow but uneven accumulation in the tumor bed. Delivery of nano-sized agents is dependent on several factors that influence the EPR effect; 1. Regional blood flow to the tumor, 2. Permeability of the tumor vasculature, 3. Structural barriers imposed by perivascular tumor cells and extracellular matrix, 4. Intratumoral pressure. In this review, these factors will be described and methods to enhance nano-agent delivery will be reviewed.
Asunto(s)
Antineoplásicos/farmacocinética , Permeabilidad Capilar , Neoplasias/tratamiento farmacológico , Animales , Antineoplásicos/uso terapéutico , Humanos , Nanoestructuras/uso terapéutico , Neoplasias/irrigación sanguínea , Distribución TisularRESUMEN
OBJECTIVE: The objective of this study was to elucidate the mechanism of hepatic parenchyma-specific contrast of Sonazoid (microbubble contrast agent) using microscopic techniques. MATERIALS AND METHODS: Sonazoid was intravenously injected into rats to investigate the microbubble dynamics and distribution within hepatic microcirculation in exteriorized liver using intravital microscopy and to observe dose dependency of ultrasound hepatic contrast effect. In vitro and in vivo uptake of microbubbles by Kupffer cells was examined using confocal laser scanning microscopy. RESULTS: Intravital observation demonstrated freely flowing microbubbles in the sinusoid and some microbubbles co-localized with Kupffer cells. The microbubbles internalized in Kupffer cells were identified with reflected light by confocal laser scanning microscopy. The percentage of Kupffer cells taking up microbubbles was about 1% at clinical dose at which the homogeneous hepatic contrast was observed. CONCLUSIONS: The hepatic parenchyma-specific contrast by Sonazoid is due to distribution of the microbubbles in Kupffer cells.
Asunto(s)
Medios de Contraste/farmacocinética , Compuestos Férricos/farmacocinética , Hierro/farmacocinética , Macrófagos del Hígado/diagnóstico por imagen , Macrófagos del Hígado/metabolismo , Hígado/diagnóstico por imagen , Hígado/metabolismo , Óxidos/farmacocinética , Animales , Macrófagos del Hígado/citología , Hígado/citología , Masculino , Microburbujas , Especificidad de Órganos , Ratas , Ratas Wistar , Distribución Tisular , Ultrasonografía/métodosRESUMEN
In order to investigate improvement of hepatic tumor detectability by Sonazoid with phase inversion imaging, the contrast effects on the liver of metastatic carcinoma-model rabbits were evaluated by videodensitometry and visual assessment. Correlation between the contrast enhancement of Sonazoid and histopathology was examined using the same animals. Electron microscopy was performed on hepatic tissue from another healthy rabbits to identify the distribution of Sonazoid microbubbles. As a result, all tumors were smaller than 12 mm in diameter, and after intravenous injection of Sonazoid, they were surrounded with a ring of enhanced signal during the early phase (up to 30 s), followed by a clear contrast defect during the delayed phase (after 10 min). Histopathologic observation revealed that the ring-enhancement was caused by neovasculature in the tumor, and the contrast defects corresponded to living and dead parts of tumors, which lack Kupffer cells. Videodensitometric differences between tumor and healthy tissue markedly increased at delayed phase, and visual detectability of tumors was improved when Sonazoid was used. Ultrastructural analysis showed microbubble-like structures in Kupffer cells, which indicated that Sonazoid microbubbles were taken up with these cells. In conclusion, Sonazoid, used with phase inversion imaging, greatly increases the detectability of small hepatic tumors by highlighting neovascularity at early phase and providing clear contrast defects due to absence of Kupffer cells, which take up Sonazoid microbubbles, at delayed phase.
Asunto(s)
Medios de Contraste , Compuestos Férricos , Hierro , Neoplasias Hepáticas Experimentales/diagnóstico por imagen , Hígado/diagnóstico por imagen , Microburbujas , Óxidos , Animales , Hígado/ultraestructura , Neoplasias Hepáticas Experimentales/patología , Masculino , Conejos , UltrasonografíaRESUMEN
The liver contrast effects of Sonazoid in two ultrasonographic imaging modes, gray-scale conventional and harmonic, were examined as a time-related study in normal rabbits, and evaluated quantitatively and visually with tumor-model rabbits to estimate the diagnostic potential. Peak enhancement of vessels and parenchyma was observed 1 min after injection in both modes, although signal enhancement in the parenchyma lasted for 120 min compared with rapid decay (5-10 min) in vessels. When Sonazoid was intravenously injected into metastatic carcinoma-model (VX-2) rabbits, all hepatic tumors showed ring enhancement in the early phase followed by clear contrast defects in the delayed phase, because signal enhancement remained only in normal parenchyma. Visual analysis scores for the diagnosis of tumors were improved by Sonazoid injection, and the videodensitometric differences between tumor and normal tissues were significantly greater after injection. Although the harmonic mode tended to show better contrast effects, the conventional mode provided significant contrast enhancement in this hepatic tumor-model. Sonazoid might be useful for the detection of undifferentiated tumors in the liver by making it possible to visualize neovascularity in the early phase and clear contrast defects in the delayed phase, not only in the harmonic but also in the conventional mode.