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1.
Int J Mol Sci ; 24(23)2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-38068905

RESUMO

Raman spectroscopy has emerged as a powerful tool in medical, biochemical, and biological research with high specificity, sensitivity, and spatial and temporal resolution. Recent advanced Raman systems, such as portable Raman systems and fiber-optic probes, provide the potential for accurate in vivo discrimination between healthy and cancerous tissues. In our study, a portable Raman probe spectrometer was tested in immunosuppressed mice for the in vivo localization of colorectal cancer malignancies from normal tissue margins. The acquired Raman spectra were preprocessed, and principal component analysis (PCA) was performed to facilitate discrimination between malignant and normal tissues and to highlight their biochemical differences using loading plots. A transfer learning model based on a one-dimensional convolutional neural network (1D-CNN) was employed for the Raman spectra data to assess the classification accuracy of Raman spectra in live animals. The 1D-CNN model yielded an 89.9% accuracy and 91.4% precision in tissue classification. Our results contribute to the field of Raman spectroscopy in cancer diagnosis, highlighting its promising role within clinical applications.


Assuntos
Neoplasias Colorretais , Aprendizado Profundo , Animais , Camundongos , Análise Espectral Raman/métodos , Redes Neurais de Computação , Neoplasias Colorretais/diagnóstico
2.
J Imaging ; 9(12)2023 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-38132679

RESUMO

Raman spectroscopy (RS) techniques are attracting attention in the medical field as a promising tool for real-time biochemical analyses. The integration of artificial intelligence (AI) algorithms with RS has greatly enhanced its ability to accurately classify spectral data in vivo. This combination has opened up new possibilities for precise and efficient analysis in medical applications. In this study, healthy and cancerous specimens from 22 patients who underwent open colorectal surgery were collected. By using these spectral data, we investigate an optimal preprocessing pipeline for statistical analysis using AI techniques. This exploration entails proposing preprocessing methods and algorithms to enhance classification outcomes. The research encompasses a thorough ablation study comparing machine learning and deep learning algorithms toward the advancement of the clinical applicability of RS. The results indicate substantial accuracy improvements using techniques like baseline correction, L2 normalization, filtering, and PCA, yielding an overall accuracy enhancement of 15.8%. In comparing various algorithms, machine learning models, such as XGBoost and Random Forest, demonstrate effectiveness in classifying both normal and abnormal tissues. Similarly, deep learning models, such as 1D-Resnet and particularly the 1D-CNN model, exhibit superior performance in classifying abnormal cases. This research contributes valuable insights into the integration of AI in medical diagnostics and expands the potential of RS methods for achieving accurate malignancy classification.

3.
J Imaging ; 9(12)2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38132685

RESUMO

This study establishes typical Diagnostic Reference Levels (DRL) values and assesses patient doses in computed tomography (CT)-guided biopsy procedures. The Effective Dose (ED), Entrance Skin Dose (ESD), and Size-Specific Dose Estimate (SSDE) were calculated using the relevant literature-derived conversion factors. A retrospective analysis of 226 CT-guided biopsies across five categories (Iliac bone, liver, lung, mediastinum, and para-aortic lymph nodes) was conducted. Typical DRL values were computed as median distributions, following guidelines from the International Commission on Radiological Protection (ICRP) Publication 135. DRLs for helical mode CT acquisitions were set at 9.7 mGy for Iliac bone, 8.9 mGy for liver, 8.8 mGy for lung, 7.9 mGy for mediastinal mass, and 9 mGy for para-aortic lymph nodes biopsies. In contrast, DRLs for biopsy acquisitions were 7.3 mGy, 7.7 mGy, 5.6 mGy, 5.6 mGy, and 7.4 mGy, respectively. Median SSDE values varied from 7.6 mGy to 10 mGy for biopsy acquisitions and from 11.3 mGy to 12.6 mGy for helical scans. Median ED values ranged from 1.6 mSv to 5.7 mSv for biopsy scans and from 3.9 mSv to 9.3 mSv for helical scans. The study highlights the significance of using DRLs for optimizing CT-guided biopsy procedures, revealing notable variations in radiation exposure between helical scans covering entire anatomical regions and localized biopsy acquisitions.

4.
Biomolecules ; 13(12)2023 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-38136591

RESUMO

Cervical cancer remains a pressing global health concern, necessitating advanced therapeutic strategies. Radiotherapy, a fundamental treatment modality, has faced challenges such as targeted dose deposition and radiation exposure to healthy tissues, limiting optimal outcomes. To address these hurdles, nanomaterials, specifically gold nanoparticles (AuNPs), have emerged as a promising avenue. This study delves into the realm of cervical cancer radiotherapy through the meticulous exploration of AuNPs' impact. Utilizing ex vivo experiments involving cell lines, this research dissected intricate radiobiological interactions. Detailed scrutiny of cell survival curves, dose enhancement factors (DEFs), and apoptosis in both cancer and normal cervical cells revealed profound insights. The outcomes showcased the substantial enhancement of radiation responses in cancer cells following AuNP treatment, resulting in heightened cell death and apoptotic levels. Significantly, the most pronounced effects were observed 24 h post-irradiation, emphasizing the pivotal role of timing in AuNPs' efficacy. Importantly, AuNPs exhibited targeted precision, selectively impacting cancer cells while preserving normal cells. This study illuminates the potential of AuNPs as potent radiosensitizers in cervical cancer therapy, offering a tailored and efficient approach. Through meticulous ex vivo experimentation, this research expands our comprehension of the complex dynamics between AuNPs and cells, laying the foundation for their optimized clinical utilization.


Assuntos
Nanopartículas Metálicas , Neoplasias do Colo do Útero , Feminino , Humanos , Ouro/farmacologia , Ouro/uso terapêutico , Neoplasias do Colo do Útero/radioterapia , Neoplasias do Colo do Útero/tratamento farmacológico , Nanopartículas Metálicas/uso terapêutico , Linhagem Celular Tumoral , Apoptose
5.
Int J Mol Sci ; 23(24)2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36555249

RESUMO

Modeling ionizing radiation interaction with biological matter is a major scientific challenge, especially for protons that are nowadays widely used in cancer treatment. That presupposes a sound understanding of the mechanisms that take place from the early events of the induction of DNA damage. Herein, we present results of irradiation-induced complex DNA damage measurements using plasmid pBR322 along a typical Proton Treatment Plan at the MedAustron proton and carbon beam therapy facility (energy 137-198 MeV and Linear Energy Transfer (LET) range 1-9 keV/µm), by means of Agarose Gel Electrophoresis and DNA fragmentation using Atomic Force Microscopy (AFM). The induction rate Mbp-1 Gy-1 for each type of damage, single strand breaks (SSBs), double-strand breaks (DSBs), base lesions and non-DSB clusters was measured after irradiations in solutions with varying scavenging capacity containing 2-amino-2-(hydroxymethyl)propane-1,3-diol (Tris) and coumarin-3-carboxylic acid (C3CA) as scavengers. Our combined results reveal the determining role of LET and Reactive Oxygen Species (ROS) in DNA fragmentation. Furthermore, AFM used to measure apparent DNA lengths provided us with insights into the role of increasing LET in the induction of highly complex DNA damage.


Assuntos
Terapia com Prótons , Prótons , Dano ao DNA , DNA/genética , Plasmídeos/genética
6.
Front Biosci (Landmark Ed) ; 27(9): 255, 2022 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-36224003

RESUMO

BACKGROUND: Ferredoxin reductase (FDXR) has already been reported as a promising biomarker for estimating radiation doses in radiotherapy. This study aimed to investigate the responsiveness of FDXR on pediatric population exposed to ionizing radiation (X-rays) during pediatric interventional cardiology (IC) procedures. PATIENTS AND METHODS: Peripheral blood was collected by venipuncture from 24 pediatric donors before and 24 hours after the IC procedure. To estimate the effective dose, demographic data and Air Kerma-Area Product (PKA) were recorded for each patient. The relative quantification (RQ) of the FDXR gene in irradiated patient blood samples compared to the non-irradiated blood samples was determined using qPCR analysis. The relative values of FDXR were log- transformed. RESULTS: The effective dose ranged from 0.002 mSv to 8.004 mSv. Over this radiation exposure range, the FDXR gene expression varied randomly with the effective dose. Up-regulation in FDXR expression was observed in 17 patients and down-regulation in 7 patients. CONCLUSIONS: Further studies in a larger cohort of pediatric patients along with the record of clinical data are needed to determine whether FDXR gene expression is an effective biomarker for radiation exposure estimation in pediatric imaging.


Assuntos
Cardiologia , Exposição à Radiação , Biomarcadores , Criança , Ferredoxinas , Expressão Gênica , Humanos , Oxirredutases , Exposição à Radiação/efeitos adversos
7.
World J Clin Oncol ; 13(7): 553-566, 2022 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-36157164

RESUMO

Cancer is a leading cause of death worldwide. Nowadays, the therapies are inadequate and spur demand for improved technologies. Rapid growth in nanotechnology and novel nanomedicine products represents an opportunity to achieve sophisticated targeting strategies and multi-functionality. Nanomedicine is increasingly used to develop new cancer diagnosis and treatment methods since this technology can modulate the biodistribution and the target site accumulation of chemotherapeutic drugs, thereby reducing their toxicity. Cancer nanotechnology and cancer immunotherapy are two parallel themes that have emerged over the last few decades while searching for a cure for cancer. Immunotherapy is revolutionizing cancer treatment, as it can achieve unprecedented responses in advanced-stage patients, including complete cures and long-term survival. A deeper understanding of the human immune system allows the establishment of combination regimens in which immunotherapy is combined with other treatment modalities (as in the case of the nanodrug Ferumoxytol). Furthermore, the combination of gene therapy approaches with nanotechnology that aims to silence or express cancer-relevant genes via one-time treatment is gradually progressing from bench to bedside. The most common example includes lipid-based nanoparticles that target VEGF-Α and KRAS pathways. This review focuses on nanoparticle-based platforms utilized in recent advances aiming to increase the efficacy of currently available cancer therapies. The insights provided and the evidence obtained in this paper indicate a bright future ahead for immuno-oncology applications of engineering nanomedicines.

8.
Cancers (Basel) ; 14(9)2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35565296

RESUMO

The recent progress in Nanotechnology has introduced Gold Nanoparticles (AuNPs) as promising radiosensitizing agents in radiation oncology. This work aims to estimate dose enhancement due to the presence of AuNPs inside an irradiated water region through Monte Carlo calculations. The GATE platform was used to simulate 6 MV photon histories generated from a TrueBeam® linear accelerator with and without a Flattening Filter (FF) and model AuNPs clusters. The AuNPs size, concentration and distribution pattern were examined. To investigate different clinical irradiation conditions, the effect of field size, presence of FF and placement of AuNPs in water were evaluated. The range of Dose Enhancement Factors (DEF = DoseAu/DoseWater) calculated in this study is 0.99 ± 0.01-1.26 ± 0.02 depending on photon beam quality, distance from AuNPs surface, AuNPs size and concentration and pattern of distribution. The highest DEF is reported for irradiation using un-flattened photon beams and at close distances from AuNPs. The obtained findings suggest that dose deposition could be increased in regions that represent whole cells or subcellular targets (mitochondria, cell nucleus, etc.). Nevertheless, further and consistent research is needed in order to make a step toward AuNP-aided radiotherapy in clinical practice.

9.
Cancers (Basel) ; 14(5)2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35267451

RESUMO

Accurate in situ diagnosis and optimal surgical removal of a malignancy constitute key elements in reducing cancer-related morbidity and mortality. In surgical oncology, the accurate discrimination between healthy and cancerous tissues is critical for the postoperative care of the patient. Conventional imaging techniques have attempted to serve as adjuvant tools for in situ biopsy and surgery guidance. However, no single imaging modality has been proven sufficient in terms of specificity, sensitivity, multiplexing capacity, spatial and temporal resolution. Moreover, most techniques are unable to provide information regarding the molecular tissue composition. In this review, we highlight the potential of Raman spectroscopy as a spectroscopic technique with high detection sensitivity and spatial resolution for distinguishing healthy from malignant margins in microscopic scale and in real time. A Raman spectrum constitutes an intrinsic "molecular finger-print" of the tissue and any biochemical alteration related to inflammatory or cancerous tissue state is reflected on its Raman spectral fingerprint. Nowadays, advanced Raman systems coupled with modern instrumentation devices and machine learning methods are entering the clinical arena as adjunct tools towards personalized and optimized efficacy in surgical oncology.

10.
Cancers (Basel) ; 14(6)2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35326698

RESUMO

Apoptosis induction is a common therapeutic approach. However, many cancer cells are resistant to apoptotic death and alternative cell death pathways including pyroptosis and necroptosis need to be triggered. At the same time, danger signals that include HMGB1 and HSP70 can be secreted/released by damaged cancer cells that boost antitumor immunity. We studied the cytotoxic effects of AgAu NPs, Ag NPs and Au NPs with regard to the programmed cell death (apoptosis, necroptosis, pyroptosis) and the secretion/release of HSP70 and HMGB1. Cancer cell lines were incubated with 30, 40 and 50 µg/mL of AgAu NPs, Ag NPs and Au NPs. Cytotoxicity was estimated using the MTS assay, and mRNA fold change of CASP1, CASP3, BCL-2, ZPB1, HMGB1, HSP70, CXCL8, CSF1, CCL20, NLRP3, IL-1ß and IL-18 was used to investigate the associated programmed cell death. Extracellular levels of HMGB1 and IL-1ß were investigated using the ELISA technique. The nanoparticles showed a dose dependent toxicity. Pyroptosis was triggered for LNCaP and MDA-MB-231 cells, and necroptosis for MDA-MB-231 cells. HCT116 cells experience apoptotic death and show increased levels of extracellular HMGB1. Our results suggest that in a manner dependent of the cellular microenvironment, AgAu NPs trigger mixed programmed cell death in P53 deficient MDA-MB-231 cells, while they also trigger IL-1ß release in MDA-MB-231 and LNCaP cells and release of HMGB1 in HCT116 cells.

11.
Cancers (Basel) ; 13(13)2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34202342

RESUMO

Many different tumor-targeted strategies are under development worldwide to limit the side effects and improve the effectiveness of cancer therapies. One promising method is to enhance the radiosensitization of the cancer cells while reducing or maintaining the normal tissue complication probability during radiation therapy using metallic nanoparticles (NPs). Radiotherapy with MV photons is more commonly available and applied in cancer clinics than high LET particle radiotherapy, so the addition of high-Z NPs has the potential to further increase the efficacy of photon radiotherapy in terms of NP radiosensitization. Generally, when using X-rays, mainly the inner electron shells are ionized, which creates cascades of both low and high energy Auger electrons. When using high LET particles, mainly the outer shells are ionized, which give electrons with lower energies than when using X-rays. The amount of the produced low energy electrons is higher when exposing NPs to heavy charged particles than when exposing them to X-rays. Since ions traverse the material along tracks, and therefore give rise to a much more inhomogeneous dose distributions than X-rays, there might be a need to introduce a higher number of NPs when using ions compared to when using X-rays to create enough primary and secondary electrons to get the desired dose escalations. This raises the questions of toxicity. This paper provides a review of the fundamental processes controlling the outcome of metallic NP-boosted photon beam and ion beam radiation therapy and presents some experimental procedures to study the biological effects of NPs' radiosensitization. The overview shows the need for more systematic studies of the behavior of NPs when exposed to different kinds of ionizing radiation before applying metallic-based NPs in clinical practice to improve the effect of IR therapy.

12.
Cardiovasc Intervent Radiol ; 44(6): 857-865, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34009422

RESUMO

The article is part of the series of articles on radiation protection. You can find further articles in the special section of the CVIR issue. The expanding applications of interventional procedures coupled with the potential harmful effects of ionizing radiation highlight the need to assess the delivered radiation dose and establish an effective radiation protection program, particularly in the radiosensitive pediatric population. Given the complexity and heterogeneity of interventional procedures as well as the unique characteristics of children, the management of radiation dose is proving to be quite challenging. The aim of the current article is to provide an overview of the radiation exposure in pediatric patients during interventional procedures focusing on the importance of radiation protection in the pediatric population, the reported radiation doses and the techniques of minimizing radiation dose.


Assuntos
Segurança do Paciente , Pediatria , Doses de Radiação , Exposição à Radiação/estatística & dados numéricos , Proteção Radiológica/métodos , Radiografia Intervencionista/métodos , Criança , Humanos , Radiografia Intervencionista/efeitos adversos
13.
Cardiovasc Intervent Radiol ; 44(6): 829-834, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33988729

RESUMO

The article is part of the series of articles on radiation protection. You can find further articles in the special section of the CVIR issue. Lately, more advanced techniques have been introduced in medical imaging expanding the diagnostic and therapeutic applications of ionizing radiation. Among the various strategies that have been proposed for the management of radiation exposure, education and training seem to have a strong impact on radiation protection and dose reduction. However, according to several studies, medical professionals appear to lack knowledge on basic radiation protection aspects. Therefore, the establishment of an accreditation and certification system in radiation protection for all medical professionals employing ionizing radiation is considered as high priority. The purpose of this review article is to highlight the importance of education and training in radiation protection, provide recommendations for an effective educational program and propose an educational program structure for the different medical specialties.


Assuntos
Exposição à Radiação/prevenção & controle , Proteção Radiológica/métodos , Radiologia/educação , Humanos , Medicina
14.
Phys Med ; 80: 57-64, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33115700

RESUMO

PURPOSE: Over the last decades, Gold Nanoparticles (AuNPs) have been presented as an innovative approach in radiotherapy (RT) enhancement. Several studies have proven that the irradiation of tumors containing AuNPs could lead to more effective tumor control than irradiation alone. Studies with low kV photons and AuNPs conclude in encouraging results regarding the level of radioenhancement. However, experimental and theoretical studies with MV photons report controversial findings concerning the correlation between dose enhancement effect and tumor cell killing. The great variation in the experimental protocols and simulations complicates the comparison of their outcomes and depicts the need for limiting the variety of investigated parameters. Our purpose is to point out a possible direction for building realistic Monte Carlo (MC) models that could end up with promising results in MV photons RT enhancement. METHODS: We explored published in silico studies concerning AuNPs enhanced RT from 2010 to 2019. In this review, we discuss the different AuNPs and MV photon beams characteristics that have been reported and their effect in dose enhancement. RESULTS: AuNPs size, concentration, type of distribution along with photon beams energy and the presence of flattening filter in linear accelerators seem to be the major parameters that determine AuNPs radioenhancement in silico. CONCLUSIONS: Prior to AuNPs clinical translation in photon radiotherapy, in silico studies should emphasize on nanodosimetry and track structure codes than condensed history ones. Toxicity estimation and biological aspects should be implemented in MC simulations so as to achieve accurate and realistic modelling of AuNPs driven RT.


Assuntos
Ouro , Nanopartículas Metálicas , Método de Monte Carlo , Aceleradores de Partículas , Fótons , Dosagem Radioterapêutica
15.
Int J Nanomedicine ; 15: 6019-6032, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32848399

RESUMO

PURPOSE: To evaluate the antitumor efficacy of Ag3Au1Trp1:2NPs in a SCID mouse cancer model, with respect to their effect on tumor growth, on tumor's metastatic potential and the underlying molecular mechanism. SUBJECTS AND METHODS: Ag3Au1Trp1:2NPs were radiolabeled with Gallium-68 and the biodistribution was studied in Swiss mice without tumors and in SCID mice bearing tumors. SCID mice received intratumoral Ag3Au1Trp1:2NPs and tumor size was measured using calipers. Lung and liver tissues were extracted and studied microscopically for the detection of any metastatic sites. Changes in the Caspase-3 and TNF-related apoptosis-inducing ligand (TRAIL) were also investigated using real-time PCR and Western blot techniques, respectively. RESULTS: In the 4T1 tumor-bearing SCID mice, Ag3Au1Trp1:2NPs showed quick passive accumulation at tumor sites at 30 mins post-injection. Mice that received the highest dose of NPs (5.6mg/mL) demonstrated a 1.9-fold lower tumor volume compared to that of the control group at 11 days post-injection, while mice that did not receive NPs showed metastatic sites in liver and lung. Extracted tumor tissue of treated mice revealed increased Casp-3 mRNA levels as well as elevated TRAIL protein levels. CONCLUSION: Based on our results, Ag3Au1Trp1:2NPs express anti-tumor and anti-metastatic effects in vivo. Ag3Au1Trp1:2NPs also reach tumor site via the enhancement and retention effect which results in the apoptotic death of cancerous cells selectively via the extrinsic TRAIL-dependent pathway.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Nanopartículas Metálicas/uso terapêutico , Neoplasias Experimentais/patologia , Animais , Antineoplásicos/farmacocinética , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Feminino , Radioisótopos de Gálio/química , Ouro/química , Ouro/farmacologia , Neoplasias Hepáticas/prevenção & controle , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/prevenção & controle , Neoplasias Pulmonares/secundário , Nanopartículas Metálicas/química , Camundongos SCID , Neoplasias Experimentais/tratamento farmacológico , Prata/química , Prata/farmacologia , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Distribuição Tecidual , Carga Tumoral
16.
Artif Cells Nanomed Biotechnol ; 46(sup3): S389-S398, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30371113

RESUMO

Au/Ag bimetallic nanoparticles (BNPs) exhibit a wide range of excellent electronic, chemical, biological, mechanical and thermal properties due to synergistic effects. However, critical questions regarding stability, biocompatibility and their cytotoxic effects remain to be answered. In this study, Ag/Au BNPs have been synthesized as "alloy" via a chemical reduction method using double molar excess of tryptophan [ν(M):ν(Trp) = 1:2]. We then estimated their toxicity in HCT116, 4T1, HUH7 and HEK293 cell lines in monocellular and spheroid cultures. Ag/Au nanoparticles with metal ratio 3:1, had the maximal antitumor effect in cancer cell lines, while the toxicity was found significantly decreased in non-cancerous cell lines. Our results were also compared to previous data regarding Ag/Au using single molar excess of tryptophan [ν(M):ν(Trp) = 1:1], suggesting that tryptophan has a protective effect on HEK293 and not in cancer cells. Aiming to investigate the molecular mechanism behind nanopartricles cytotoxicity, we studied the expression of cell cycle and apoptosis related genes on HCT116, 4T1, and HUH7 monocellular culture. Hence, we showed that bimetallic cytotoxicity is mediated via the caspase and the p53/Bax/Bcl-2 apoptotic pathway. In conclusion, our study suggests tryptophan ratio along with metal ratio used in Ag/Au BNPs as a successful way to control the toxicity in cancer cells towards non-cancerous cells, underlying the potency of bimetallic nanoparticles as selective anti-tumor agents.


Assuntos
Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Ouro , Nanopartículas Metálicas/química , Neoplasias , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Prata , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/metabolismo , Ouro/química , Ouro/farmacologia , Células HCT116 , Células HEK293 , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Prata/química , Prata/farmacologia
17.
Cancers (Basel) ; 9(12)2017 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-29257070

RESUMO

Many tumor-targeted strategies have been used worldwide to limit the side effects and improve the effectiveness of therapies, such as chemotherapy, radiotherapy (RT), etc. Biophotonic therapy modalities comprise very promising alternative techniques for cancer treatment with minimal invasiveness and side-effects. These modalities use light e.g., laser irradiation in an extracorporeal or intravenous mode to activate photosensitizer agents with selectivity in the target tissue. Photothermal therapy (PTT) is a minimally invasive technique for cancer treatment which uses laser-activated photoabsorbers to convert photon energy into heat sufficient to induce cells destruction via apoptosis, necroptosis and/or necrosis. During the last decade, PTT has attracted an increased interest since the therapy can be combined with customized functionalized nanoparticles (NPs). Recent advances in nanotechnology have given rise to generation of various types of NPs, like gold NPs (AuNPs), designed to act both as radiosensitizers and photothermal sensitizing agents due to their unique optical and electrical properties i.e., functioning in dual mode. Functionalized AuNPS can be employed in combination with non-ionizing and ionizing radiation to significantly improve the efficacy of cancer treatment while at the same time sparing normal tissues. Here, we first provide an overview of the use of NPs for cancer therapy. Then we review many recent advances on the use of gold NPs in PTT, RT and PTT/RT based on different types of AuNPs, irradiation conditions and protocols. We refer to the interaction mechanisms of AuNPs with cancer cells via the effects of non-ionizing and ionizing radiations and we provide recent existing experimental data as a baseline for the design of optimized protocols in PTT, RT and PTT/RT combined treatment.

18.
Anticancer Res ; 37(3): 1105-1112, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28314271

RESUMO

BACKGROUND: We performed an epigenetic analysis of the first exon of the hVIM gene and the SFRP2 in circulating tumor cells (CTCs) and correlation with the corresponding primary colorectal cancer (CRC) tissue. PATIENTS AND METHODS: CTCs detection in 52 colorectal cancer patients was managed by a multi-marker immunomagnetic method with the use of quantum dots (QDs). To determine methylation levels we used high-resolution melting (HRM) technology. RESULTS: In the case of VIM we found 76.9% methylated samples, compared to 53.8% in tissue samples. Regarding SFRP2 promoter methylation levels in tissue and CTCs samples, 67.3% and 73.1%, were found methylated respectively. Correlation analysis of methylation levels with KRAS and BRAF mutations (performed in our previous study) demonstrates that high-methylation epigenotype strongly correlates to BRAF mutation. CONCLUSION: CTCs is a promising diagnostic tool. The combination of genetic mutations and epigenetic aberrations specifically in CTCs, will ameliorate CRC diagnosis in the future.


Assuntos
Neoplasias Colorretais/sangue , Neoplasias Colorretais/genética , Metilação de DNA , Células Neoplásicas Circulantes , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Aberrações Cromossômicas , Epigênese Genética , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Análise de Sequência com Séries de Oligonucleotídeos , Oncogenes , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Pontos Quânticos
19.
J Neuroimaging ; 26(2): 161-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26932522

RESUMO

MRI is a powerful tool for the diagnosis and management for a variety of central nervous system (CNS) diseases. Ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles are a novel category of MRI contrast agents that seem to play a crucial role in the imaging of CNS. Due to their physical properties, USPIOs act as blood pool agents. USPIOs improve visualization of tumor vasculature and relative cerebral blood volume measurements, tumor-associated inflammation, inflammatory-immune mediated disorders, stroke and vascular malformations. Ferumoxytol, a new type of USPIO agent, appears to have ideal characteristics for the imaging of CNS. The last few years, ferumoxytol has been successfully used to image CNS neoplasms, CNS inflammations and cerebral malformations offering useful information on cellular and molecular level. In addition, ferumoxytol studies focused on the pathophysiology of other CNS disorders like multiple sclerosis and epilepsy are already in progress. Aim of this review article is to provide the potential role of USPIO-enhanced MRI and the latest clinical applications of ferumoxytol agent in CNS imaging.


Assuntos
Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Neuroimagem/métodos , Meios de Contraste , Dextranos , Óxido Ferroso-Férrico , Humanos , Nanopartículas de Magnetita
20.
World J Radiol ; 8(2): 142-7, 2016 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-26981223

RESUMO

The increased use of ionization radiation for diagnostic and therapeutic purposes, the rapid advances in computed tomography as well as the high radiation doses delivered by interventional procedures have raised serious safety and health concerns for both patients and medical staff and have necessitated the establishment of a radiation protection culture (RPC) in every Radiology Department. RPC is a newly introduced concept. The term culture describes the combination of attitudes, beliefs, practices and rules among the professionals, staff and patients regarding to radiation protection. Most of the time, the challenge is to improve rather than to build a RPC. The establishment of a RPC requires continuing education of the staff and professional, effective communication among stakeholders of all levels and implementation of quality assurance programs. The RPC creation is being driven from the highest level. Leadership, professionals and associate societies are recognized to play a vital role in the embedding and promotion of RPC in a Medical Unit. The establishment of a RPC enables the reduction of the radiation dose, enhances radiation risk awareness, minimizes unsafe practices, and improves the quality of a radiation protection program. The purpose of this review paper is to describe the role and highlight the importance of establishing a strong RPC in Radiology Departments with an emphasis on promoting RPC in the Interventional Radiology environment.

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