RESUMO
Colloidal nanoparticles exhibiting anisotropic morphologies are preferred in the structural design of spectroscopically active substrates due to the remarkable optical properties of this type of nano-object. In the particular case of star-like nanoparticles, their sharp tips can act as antennae for capturing and amplifying the incident light, as well as for enhancing the light emitted by nearby fluorophores or the scattering efficiency of Raman active molecules. In the current work, we aimed to implement such star-shaped nanoparticles in the fabrication of nanoparticle films and explore their use as solid plasmonic substrates for surface-enhanced optical spectroscopies. High-density, compact and robust self-assembled gold nanostar films were prepared by directly depositing them from aqueous colloidal suspension on polystyrene plates through convective self-assembly. We investigated the role of the polymeric coating, herein polyvinylpyrrolidone (PVP), in the particle assembly process, the resulting morphology and consequently, the plasmonic response of the obtained films. The efficacy of the plasmonic films as dual-mode surface-enhanced fluorescence (SEF) and surface-enhanced Raman scattering (SERS) substrates was evidenced by testing Nile Blue A (NB) and Rhodamine 800 (Rh800) molecular chromophores under visible (633 nm) versus NIR (785 nm) laser excitation. Steady-state and time-resolved fluorescence investigations highlight the fluorescence intensity and fluorescence lifetime modification effects. The experimental results were corroborated with theoretical modelling by finite-difference time-domain (FDTD) simulations. Furthermore, to prove the extended applicability of the proposed substrates in the detection of biologically relevant molecules, we tested their SERS efficiency for sensing metanephrine, a metabolite currently used for the biochemical diagnosis of neuroendocrine tumors, at concentration levels similar to other catecholamine metabolites.
RESUMO
According to the latest World Health Organization statistics, around 50 to 80 million people worldwide suffer from infertility, amongst which male factors are responsible for around 20 to 30 % of all infertility cases while 50 % were attributed to the female ones. As it is becoming a recurrent health problem worldwide, clinicians require more accurate methods for the improvement of both diagnosis and treatment schemes. By emphasizing the potential use of innovative methods for the rapid identification of the infertility causes, this review presents the news from this dynamic domain and highlights the benefits brought by emerging research fields. A systematic description of the standard techniques used in clinical protocols for diagnosing infertility in both genders is firstly provided, followed by the presentation of more accurate and comprehensive nanotechnology-related analysis methods such as nanoscopic-resolution imaging, biosensing approaches and assays that employ nanomaterials in their design. Consequently, the implementation of nanotechnology related tools in clinical practice, as recently demonstrated in the selection of spermatozoa, the detection of key proteins in the fertilization process or the testing of DNA integrity or the evaluation of oocyte quality, might confer excellent advantages both for improving the assessment of infertility, and for the success of the fertilization process.
Assuntos
Infertilidade Masculina , Feminino , Masculino , Humanos , Infertilidade Masculina/diagnóstico , Infertilidade Masculina/terapia , Infertilidade Masculina/etiologia , Espermatozoides , NanotecnologiaRESUMO
It is well known that surface topography plays an important role in cell behavior, including adhesion, migration, orientation, elongation, proliferation and differentiation. Studying these cell functions is essential in order to better understand and control specific characteristics of the cells and thus to enhance their potential in various biomedical applications. This review proposes to investigate the extent to which various surface relief patterns, imprinted in biopolymer films or in polymeric films coated with biopolymers, by utilizing specific lithographic techniques, influence cell behavior and development. We aim to understand how characteristics such as shape, dimension or chemical functionality of surface relief patterns alter the orientation and elongation of cells, and thus, finally make their mark on the cell proliferation and differentiation. We infer that such an insight is a prerequisite for pushing forward the comprehension of the methodologies and technologies used in tissue engineering applications and products, including skin or bone implants and wound or fracture healing.
Assuntos
Polímeros , Engenharia Tecidual , Biopolímeros , Adesão Celular , Diferenciação Celular/fisiologia , Proliferação de Células , Próteses e Implantes , Propriedades de Superfície , Engenharia Tecidual/métodosRESUMO
Background and Objectives: Vitamin D (Vit. D) is known for its role in the skeletal system. Vit. D deficiency is also widely researched for its effects on the healing of fractures, bone defects, and osseointegration of implants. In the literature, there are studies that investigated the effects of dietary supplementation with Vit. D to reduce Vit. D deficiency, but increasing the serum level of this vitamin takes time. Therefore, an attempt has been made to combat the effect of Vit. D deficiency through topical applications. The aim of this article was to conduct a review of the existing bibliographic data that investigate the effect of Vit. D on bone regeneration. Materials and Methods: In order to carry out this review, an electronic search was made in several databases and the articles found were selected and analyzed. Results: The in vitro studies' results demonstrated that Vit. D has a high therapeutic potential by enhancing the differentiation of stem cells in osteoblasts. Human and animal studies were conducting using various methods, but most of them revealed that Vit. D has a positive influence on the process of bone regeneration. Conclusions: The overall results of the research showed that, indeed, Vit. D is beneficial for bone regeneration; however, most of the studies imply that a thorough research is still needed for finding the most effective mode of administration and the dose needed in order to achieve the desired effect.
Assuntos
Fraturas Ósseas , Deficiência de Vitamina D , Animais , Humanos , Vitamina D/farmacologia , Vitamina D/uso terapêutico , Vitaminas/uso terapêutico , Regeneração ÓsseaRESUMO
Concomitant with advances in research regarding the role of miRNAs in sustaining carcinogenesis, major concerns about their delivery options for anticancer therapies have been raised. The answer to this problem may come from the world of nanoparticles such as liposomes, exosomes, polymers, dendrimers, mesoporous silica nanoparticles, quantum dots and metal-based nanoparticles which have been proved as versatile and valuable vehicles for many biomolecules including miRNAs. In another train of thoughts, the general scheme of miRNA modulation consists in inhibition of oncomiRNA expression and restoration of tumor suppressor ones. The codelivery of two miRNAs or miRNAs in combination with chemotherapeutics or small molecules was also proposed. The present review presents the latest advancements in miRNA delivery based on nanoparticle-related strategies.
Assuntos
MicroRNAs/administração & dosagem , Neoplasias/terapia , Animais , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Técnicas de Transferência de Genes , Terapia Genética/métodos , Humanos , MicroRNAs/genética , MicroRNAs/farmacocinética , MicroRNAs/uso terapêutico , Nanomedicina/métodos , Nanopartículas/química , Neoplasias/genéticaRESUMO
Neuroendocrine tumors, such as pheochromocytoma or paraganglioma, are dangerous tumors that constitute a potential threat for a large number of patients. Currently, the biochemical diagnosis of neuroendocrine tumors is based on measurement of the direct secretory products of the adrenomedullary-sympathetic system or of their metabolites, such as catecholamines or their metanephrine derivatives, from plasma or urine. The techniques used for analysis of plasma free metanephrines, i.e. high-performance liquid chromatography or high-performance liquid chromatography coupled with mass-spectrometry are technically-demanding and time consuming, which limit their availability. Here we demonstrate a simple, fast and low-cost method for detecting metanephrine by Surface Enhanced Raman Scattering (SERS). The protocol consists in using evaporation-induced self-assembly of gold (Au) nanoparticles incubated with the analyte, on planar gold films. The assembly process produces regions with a dense distribution of both inter-particle gaps and particle-film gaps. Finite-difference time-domain simulations confirm that both kinds of gaps are locations of enhanced electromagnetic fields resulting from inter-particle and particle-film plasmonic coupling, useful for SERS amplification. Metanephrine vibrational bands assignment was performed according to density functional theory calculations. Metanephrine metabolite was detected in liquid at concentration levels lower than previously reported for other similar metabolites. The obtained results demonstrate that the Au nanoparticle/Au film exhibits noticeable SERS amplification of the adsorbed metabolite and can be used in the design of efficient, stable SERS-active substrates for the detection and identification of specific tumor markers.
Assuntos
Neoplasias das Glândulas Suprarrenais/metabolismo , Biomarcadores/metabolismo , Ouro/química , Nanopartículas Metálicas/química , Metanefrina/metabolismo , Feocromocitoma/metabolismo , Humanos , Análise Espectral Raman/métodosRESUMO
Extensive hypoxic regions are the daunting hallmark of glioblastoma, as they host aggressive stem-like cells, hinder drug delivery and shield cancer cells from the effects of radiotherapy. Nanotechnology could address most of these issues, as it employs nanoparticles (NPs) carrying drugs that selectively accumulate and achieve controlled drug release in tumor tissues. Methods overcoming the stiff interstitium and scarce vascularity within hypoxic zones include the incorporation of collagenases to degrade the collagen-rich tumor extracellular matrix, the use of multistage systems that progressively reduce NP size or of NP-loaded cells that display inherent hypoxia-targeting abilities. The unfavorable hypoxia-induced low pH could be converted into a therapeutical advantage by pH-responsive NPs or multilayer NPs, while overexpressed markers of hypoxic cells could be specifically targeted for an enhanced preferential drug delivery. Finally, promising new gene therapeutics could also be incorporated into nanovehicles, which could lead to silencing of hypoxia-specific genes that are overexpressed in cancer cells. In this review, we highlight NPs which have shown promising results in targeting cancer hypoxia and we discuss their applicability in glioblastoma, as well as possible limitations. Novel research directions in this field are also considered.
Assuntos
Glioblastoma/tratamento farmacológico , Hipóxia/tratamento farmacológico , Nanopartículas/administração & dosagem , Animais , Preparações de Ação Retardada/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , HumanosRESUMO
BACKGROUND AND OBJECTIVES: Two of the most exciting new technologies are biotechnology and nanotechnology. The science of nanostructures, or nanotechnology, is concerned with the development, testing, and use of structures and molecules with nanoscale dimensions ranging from 1 to 100 nm. The development of materials and tools with high specificity that interact directly at the subcellular level is what makes nanotechnology valuable in the medical sciences. At the cellular or tissue level, this might be converted into focused clinical applications with the greatest possible therapeutic benefits and the fewest possible side effects. The purpose of the present study was to review the literature and explore the applicability of the nanostructured materials in the process of the regeneration of the soft and hard tissues of the oral cavity. MATERIALS AND METHODS: An electronic search of articles was conducted in several databases, such as PubMed, Embase, and Web of Science, to conduct this study, and the 183 articles that were discovered were chosen and examined, and only 22 articles met the inclusion criteria in this review. RESULTS: The findings of this study demonstrate that using nanoparticles can improve the mechanical properties, biocompatibility, and osteoinductivity of biomaterials. CONCLUSIONS: Most recently, breakthroughs in tissue engineering and nanotechnology have led to significant advancements in the design and production of bone graft substitutes and hold tremendous promise for the treatment of bone abnormalities. The creation of intelligent nanostructured materials is essential for various applications and therapies, as it allows for the precise and long-term delivery of medication, which yields better results.
RESUMO
Acute myeloid leukemia (AML) is a malignancy in the myeloid lineage that is characterized by symptoms like fatigue, bleeding, infections, or anemia, and it can be fatal if untreated. In AML, mutations in tyrosine kinases (TKs) lead to enhanced tumor cell survival. The most frequent mutations in TKs are reported in Fms-like tyrosine kinase 3 (FLT3), Janus kinase 2 (JAK2), and KIT (tyrosine-protein kinase KIT), making these TKs potential targets for TK inhibitor (TKI) therapies in AML. With 30% of the mutations in TKs, mutated FLT3 is associated with poor overall survival and an increased chance of resistance to therapy. FLT3 inhibitors are used in FLT3-mutant AML, and the combination with hypomethylating agents displayed promising results. Midostaurin (MDS) is the first targeted therapy in FLT3-mutant AML, and its combination with chemotherapy showed good results. However, chemotherapies induce several side effects, and an alternative to chemotherapy might be the use of nanoparticles for better drug delivery, improved bioavailability, reduced drug resistance and induced toxicity. The herein study presents MDS-loaded gold nanoparticles and compares its efficacy with MDS alone, on both in vitro and in vivo models, using the FLT3-ITD-mutated AML cell line MV-4-11 Luc2 transfected to express luciferin. Our preclinical study suggests that MDS-loaded nanoparticles have a better tumor inhibitory effect than free drugs on in vivo models by controlling tumor growth in the first half of the treatment, while in the second part of the therapy, the tumor size was comparable to the cohort that was treatment-free.
RESUMO
The ability to easily prepare Surface Enhanced Raman Scattering (SERS) substrates by the assembly of chemically synthesized gold nanocolloids is of great interest for the advancement of SERS-based optical detection and identification of molecular species of biological or chemical interest, pollutants or warfare agents. In this work we employ three very simple strategies, which can be implemented in any laboratory without the need for specialized equipment, to prepare assemblies of citrate-stabilized spherical gold colloids: (i) drop-coating, which induces the assembly of colloids in so-called coffee rings; (ii) a simplified variant of convective self-assembly (CSA), based on water evaporation in a constrained geometry, which yields highly uniform strips of nanoparticles (NP); (iii) assembly onto chemically functionalized glass surfaces which yields randomly assembled colloids and colloidal clusters. The SERS properties of the resulting colloidal assemblies are comparatively evaluated under multiple excitation lines with p-aminothiophenol (pATP) as a model Raman scatterer. The NP strips obtained by CSA prove to be SERS-active both in the visible and NIR and possess a highly uniform SERS response as demonstrated by spectra at individually selected sites and by confocal SERS mapping. Further it is shown that these NP strips are effective for the detection of cytosine, a DNA component, and for multi-analyte SERS detection. These results, showing how an efficient SERS substrate can be obtained by a very simple assembly method from easy-to-synthesize colloidal gold NP, can have an impact on the development of analytical SERS applications.
Assuntos
Coloide de Ouro/química , Nanopartículas Metálicas/química , Nanocompostos/química , Análise Espectral Raman/métodos , Propriedades de SuperfícieRESUMO
Evaporation-induced self-assembly in colloidal droplets is a method for organising nanoparticles on substrates, with various resulting patterns. The coffee-ring pattern is among the most common ones, but its non-uniformity limits its applicability, which led to efforts for developing coffee-ring suppression strategies. Considering the wide applicability of ZnO and TiO2 nanoparticles, there is a high demand for practical means to deposit them as uniform films. Here, we present a simple approach for obtaining highly uniform thin films of ZnO and TiO2 nanoparticles by drop-coating in ambient conditions, without using surfactants or other surface chemistry modifications. Disc-like films were obtained via a restricted evaporation achieved by covering the droplets with a lid during drying, seconded by the relatively high sedimentation rate of these nanoparticles. To better understand the assembly mechanism, the influence of suspension concentration, type and temperature of the substrate, droplet volume, colloid type, and evaporation rate were studied. The method allows preparing disc-like nanoparticle films with a good control over their diameter and thickness, onto different kinds of substrates (glass, Si, polyethylene terephthalate, polystyrene). By fabricating both two-dimensional lattices and custom disc patterns we highlight the versatility of this drop-coating method and its potential for, e.g., automatized serial production processes.
RESUMO
Poly(tartaric acid) is a relatively recently described polymer that can be easily synthesized and scaled up from a readily available renewable material (tartaric acid). This article demonstrates its use in a green synthesis of gold nanoparticles, silver nanoparticles, copper particles, and magnetite nanoparticles. In this case poly(tartaric acid) acts both as a reductant and as a coating agent. To our knowledge this is the first green synthesis of several different types of nanoparticles using only one reagent (polytartrate) as both reductant and coating. The resulting particles were analyzed by XRD, TEM/SEM, EDX, FTIR, DLS, zeta-potential, XPS, and UV/VIS spectroscopy. Preliminary studies of the thermal behavior of mixtures of different types of particles with poly(tartaric acid) were also conducted. The obtained particles show different sizes depending on the material, and the coating allows for better dispersibility as well as potential further functionalization, making them potentially useful also for other applications, besides the inclusion in polymer composites.
RESUMO
Tyrosine kinase inhibitor (TKI) therapy is gaining attraction in advanced cancer therapeutics due to the ubiquity of kinases in cell survival and differentiation. Great progress was made in the past years in identifying tyrosine kinases that can function as valuable molecular targets and for the entrapment of their corresponding inhibitors in delivery compounds for triggered release. Herein we present a class of drug-delivery nanocompounds based on TKI Midostaurin-loaded gold nanoparticles that have the potential to be used as theranostic agents for the targeting of the FMS-like tyrosine kinase 3 (FLT3) in acute myeloid leukemia. We optimized the nanocompounds' formulation with loading efficiency in the 84-94% range and studied the drug release behavior in the presence of stimuli-responsive polymers. The therapeutic activity of MDS-loaded particles, superior to that of the free drug, was confirmed with toxicities depending on specific dosage ranges. No effect was observed on FLT3-negative cells or for the unloaded particles. Beyond druggability, we can track this type of nanocarrier inside biological structures as demonstrated via dark field microscopy. These properties might contribute to the facilitation of personalized drug dosage administration, critical for attaining a maximal therapeutic effect.
RESUMO
The increasing pollution of surface and groundwater bodies by pharmaceuticals is a general environmental problem requiring routine monitoring. Conventional analytical techniques used to quantify traces of pharmaceuticals are relatively expensive and generally demand long analysis times, associated with difficulties in performing field analyses. Propranolol, a widely used ß-blocker, is representative of an emerging class of pharmaceutical pollutants with a noticeable presence in the aquatic environment. In this context, we focused on developing an innovative, highly accessible analytical platform based on self-assembled metal colloidal nanoparticle films for the fast and sensitive detection of propranolol based on Surface Enhanced Raman Spectroscopy (SERS). The ideal nature of the metal used as the active SERS substrate was investigated by comparing silver and gold self-assembled colloidal nanoparticle films, and the improved enhancement observed on the gold substrate was discussed and supported by Density Functional Theory calculations, optical spectra analyses, and Finite-Difference Time-Domain simulations. Next, direct detection of propranolol at low concentrations was demonstrated, reaching the ppb regime. Finally, we showed that the self-assembled gold nanoparticle films could be successfully used as working electrodes in electrochemical-SERS analyses, opening the possibility of implementing them in a wide array of analytical applications and fundamental studies. This study reports for the first time a direct comparison between gold and silver nanoparticle films and, thus, contributes to a more rational design of nanoparticle-based SERS substrates for sensing applications.
Assuntos
Ouro , Nanopartículas Metálicas , Ouro/química , Prata/química , Nanopartículas Metálicas/química , Propranolol , Análise Espectral Raman/métodos , Preparações FarmacêuticasRESUMO
Nanosensors represent a class of emerging promising nanotools that can be used for the rapid, sensitive and specific detection of relevant molecules such as biomarkers of cancer or other diseases. The sensing platforms that rely on the exceptional physical properties of colloidal gold nanoparticles have gained a special attraction and various architectural designs were proposed with the aim of rapid and real-time detection, identification and monitoring of the capturing events. Moreover, biomarker sensing in liquid samples allows a more facile implementation of the nanosensors by circumventing the need for invasive practices such as biopsies, in favor of non-invasive investigations with potential for use as point-of-care assays. Herein, we propose a sandwich-type surface enhanced Raman scattering (SERS) immuno-nanosensor which is aimed for detecting and quantifying Carcinoembryonic antigen-related cell adhesion molecule 5 (CEA-CAM5), a protein involved in intercellular adhesion and signaling pathways that acts as a tumor marker in several types of cancer. For constructing the proposed system, colloidal gold nano spheres (GNS) and gold nano-urchins (GNU) were chemically synthesized, labeled with SERS active molecules, conjugated with polymers, functionalized with antibodies as capturing substrates and tested in two different sensing configurations: pairs of GNUs-GNUs and GNUs-GNSs. When the target antigen is present in the analyte solution, nanoparticle bridging occurs and a subsequent amplification of the characteristic Raman signal of the label molecule appears due to the formation of hot-spots in interparticle gaps. The capability of observing small analyte concentrations in liquid samples with an easy-to-handle portable Raman device makes the proposed system feasible for rapid, non-invasive and cost-effective clinical or laboratory use.
Assuntos
Nanopartículas Metálicas , Anticorpos , Ouro , Nanopartículas Metálicas/química , Polímeros/química , Análise Espectral RamanRESUMO
Future-oriented material fabrication technologies would aim to reproduce features characteristic to the natural materials into the synthetic ones. Various bio-mimicking strategies can be already used in medical industry since they can mimic the desired surface design with the help of surface patterning techniques. In this review, we highlight the most common patterning methodologies employed for the fabrication of polymeric substrates having micro or nano-features by presenting their advantages and potential utility for applications in the biomedical field. Top-down and bottom-up fabrication techniques including lithographic approaches such as photolithography, electron, proton, ion beam and block copolymer lithography, soft lithography and some advanced methods as scanning probe and particle lithography are firstly described, followed by a brief presentation of the alternative patterning techniques using biomolecule crystallization or DNA self-assembly. The potential use of synthetic- and bio-polymer patterned substrates and the so-far reported studies including analysis of molecule and cell-interface interactions, cell development, migration and differentiation are further described with emphasis onto their implementation on circulating blood cells and blood disorders. The last chapter summarizes the results found regarding the advantages of using such substrates as component parts in biosensing devices, with foreseen applicability in medical diagnosis and the clinical healthcare domain.
Assuntos
Nanotecnologia , Prótons , Comunicação Celular , DNA , Nanotecnologia/métodos , PolímerosRESUMO
The detection of Raman signals inside living cells is a topic of great interest in the study of cell biology mechanisms and for diagnostic and therapeutic applications. This work presents the synthesis and characterization of flower-shaped gold nanoparticles and demonstrates their applicability as SERS-active tags for cellular spectral detection. The particles were synthesized by a facile, rapid new route that uses ascorbic acid as a reducing agent of gold salt. Two triarylmethane dyes which are widely used as biological stains, namely malachite green oxalate and basic fuchsin, were used as Raman-active molecules and the polymer mPEG-SH as capping material. The as-prepared SERS-active nanoparticles were tested on a human retinal pigment epithelial cell line and found to present a low level of cytotoxicity and high chemical stability together with SERS sensitivity down to picomolar particle concentrations.
Assuntos
Células Epiteliais/citologia , Células Epiteliais/metabolismo , Ouro/química , Nanopartículas Metálicas/química , Análise Espectral Raman , Linhagem Celular , Proliferação de Células , Sobrevivência Celular , Humanos , Nanopartículas Metálicas/ultraestrutura , Corantes de Rosanilina/química , Corantes de Rosanilina/metabolismo , Soluções , Propriedades de SuperfícieRESUMO
We present an effective, low cost protocol to reduce the toxicity of gold nanorods induced by the presence of cetyltrimethylammonium bromide (CTAB) on their lateral surface as a result of the synthesis process. Here, we use thiolated methoxy-poly(ethylene) glycol (mPEG-SH) polymer to displace most of the CTAB bilayer cap from the particle surface. The detoxification process, chemical and structural stability of as-prepared mPEG-SH-conjugated gold nanorods were characterized using a number of techniques including localized surface plasmon resonance (LSPR), transmission electron microscopy (TEM) and surface-enhanced Raman spectroscopy (SERS). In view of future applications as near-infrared (NIR) nanoheaters in localized photothermal therapy of cancer, we investigated the thermal behaviour of mPEG-SH-conjugated gold nanorods above room temperature. We found a critical temperature at around 40 degrees C at which the adsorbed polymer layer is susceptible to undergo conformational changes. Additionally, we believe that such plasmonic nanoprobes could act as SERS-active carriers of Raman tags for application in cellular imaging. In this sense we successfully tested them as effective SERS substrates at 785 nm laser line with p-aminothiophenol (pATP) as a tag molecule.
Assuntos
Compostos de Cetrimônio/química , Ouro/química , Nanotubos/química , Polietilenoglicóis/química , Análise Espectral Raman/métodos , Cetrimônio , Compostos de Cetrimônio/efeitos adversos , Compostos de Sulfidrila/químicaRESUMO
The incidence of Acute Lymphoblastic Leukemia (ALL) is increasing globally, and it is being clinically addressed by chemotherapy, followed by immunotherapy and stem cell transplantation, all with potential life-threatening toxicities. In the need for more effective therapeutics, newly developed disease-targeted nanocompounds can thus hold real potential. In this paper, we propose a novel nanoparticle-based immunotherapeutic agent against ALL, consisting of antiCD19 antibody-conjugated, polyethylene glycol (PEG)-biocompatibilized, and Nile Blue (NB) Raman reporter-tagged gold nanoparticles of urchin-like shape (GNUs), that have a plasmonic response in the Near Infrared (NIR) spectral range. Transmission electron microscopy (TEM) images of particle-incubated CD19-positive (CD19(+)) CCRF-SB cells show that the antiCD19-PEG-NB-GNU nanocomplex is able to recognize the CD19 B-cell-specific antigen, which is a prerequisite for targeted therapy. The therapeutic effect of the particles is confirmed by cell counting, combined with cell cycle analysis by flow cytometry and MTS assay, which additionally offer insights into their mechanisms of action. Specifically, antiCD19-PEG-NB-GNUs proved superior cytotoxic effect against CCRF-SB cells when compared with the free antibody, by reducing the overall viability below 18% after 7 days treatment at a particle-bound antibody concentration of 0.17â¯ng/µl. Moreover, by combining their remarkable plasmonic properties with the possibility of Raman tagging, the proposed nanoparticles can also serve as spectroscopic imaging agents inside living cells, which validates their theranostic potential in the field of hematological oncology.
Assuntos
Antígenos CD19/imunologia , Ouro/química , Imunoconjugados/administração & dosagem , Nanopartículas Metálicas/administração & dosagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Imunoconjugados/química , Imunoterapia/métodos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Oxazinas/química , Polietilenoglicóis/química , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Análise Espectral RamanRESUMO
In this Research Article, we propose a new class of contrast agents for the detection and multimodal imaging of CD19(+) cancer lymphoblasts. The agents are based on NIR responsive hollow gold-silver nanospheres conjugated with antiCD19 monoclonal antibodies and marked with Nile Blue (NB) SERS active molecules (HNS-NB-PEG-antiCD19). Proof of concept experiments on specificity of the complex for the investigated cells was achieved by transmission electron microscopy (TEM). The microspectroscopic investigations via dark field (DF), surface-enhanced Raman spectroscopy (SERS), and two-photon excited fluorescence lifetime imaging microscopy (TPE-FLIM) corroborate with TEM and demonstrate successful and preferential internalization of the antibody-nanocomplex. The combination of the microspectroscopic techniques enables contrast and sensitivity that competes with more invasive and time demanding cell imaging modalities, while depth sectioning images provide real time localization of the nanoparticles in the whole cytoplasm at the entire depth of the cells. Our findings prove that HNS-NB-PEG-antiCD19 represent a promising type of new contrast agents with great possibility of being detected by multiple, non invasive, rapid and accessible microspectroscopic techniques and real applicability for specific targeting of CD19(+) cancer cells. Such versatile nanocomplexes combine in one single platform the detection and imaging of cancer lymphoblasts by DF, SERS, and TPE-FLIM microspectroscopy.