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To increase the therapeutic efficacy of nanoparticle (NP)-assisted photothermal therapy (PTT) and allow for a transition toward the clinical setting, it is pivotal to characterize the thermal effect induced in cancer cells and correlate it with the cell biological response, namely cell viability and cell death pathways. This study quantitatively evaluated the effects of gold nanorod (GNR)-assisted near-infrared (NIR) PTT on two different cancer cell lines, the 4T1 triple-negative breast cancer cells and the Pan02 pancreatic cancer cells. The interaction between nanomaterials and biological matrices was investigated in terms of GNR internalization and effect on cell viability at different GNR concentrations. GNR-mediated PTT was executed on both cell lines, at the same treatment settings to allow a straightforward comparison, and real-time monitored through thermographic imaging. A thermal analysis based on various parameters (i.e., maximum absolute temperature, maximum temperature change, temperature variation profile, area under the time-temperature change curve, effective thermal enhancement (ETE), and time constants) was performed to evaluate the treatment thermal outcome. While GNR treatment and NIR laser irradiation alone did not cause cell toxicity in the selected settings, their combination induced a significant reduction of cell viability in both cell lines. At the optimal experimental condition (i.e., 6 µg/mL of GNRs and 4.5 W/cm2 laser power density), GNR-assisted PTT reduced the cell viability of 4T1 and Pan02 cells by 94% and 87% and it was associated with maximum temperature changes of 25 °C and 29 °C (i.e., â¼1.8-fold increase compared to the laser-only condition), maximum absolute temperatures of 55 °C and 54 °C, and ETE values of 78% and 81%, for 4T1 and Pan02 cells, correspondingly. Also, the increase in the GNR concentration led to a decrease in the time constants, denoting faster heating kinetics upon irradiation. Furthermore, the thermal analysis parameters were correlated with the extent of cell death. Twelve hours after NIR exposure, GNR-assisted PTT was found to mainly trigger secondary apoptosis in both cell lines. The proposed study provides relevant insights into the relationship between temperature history and biological responses in the context of PTT. The findings contribute to the development of a universal methodology for evaluating thermal sensitivity upon NP-assisted PTT on different cell types and lay the groundwork for future translational studies.
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PURPOSE: To examine temporal-spatial distribution of heat generated upon laser activation in a bench model of renal calyx. To establish reference values for a safety distance between the laser fiber and healthy tissue during laser lithotripsy. METHODS: We developed an in-vitro experimental setup employing a glass pipette and laser activation under various intra-operative parameters, such as power and presence of irrigation. A thermal camera was used to monitor both temporal and spatial temperature changes during uninterrupted 60-second laser activation. We computed the thermal dose according to Sapareto and Dewey's formula at different distances from the laser fiber tip, in order to determine a safety distance. RESULTS: A positive correlation was observed between average power and the highest recorded temperature (Spearman's coefficient 0.94, p < 0.001). Irrigation was found to reduce the highest recorded temperature, with a maximum average reduction of 9.4 °C at 40 W (p = 0.002). A positive correlation existed between average power and safety distance values (Spearman's coefficient 0.86, p = 0.001). A thermal dose indicative of tissue damage was observed at 20 W without irrigation (safety distance 0.93±0.11 mm). While at 40 W, irrigation led to slight reduction in mean safety distance (4.47±0.85 vs. 5.22±0.09 mm, p = 0.08). CONCLUSIONS: Laser settings with an average power greater than 10 W deliver a thermal dose indicative of tissue damage, which increases with higher average power values. According to safety distance values from this study, a maximum of 10 W should be used in the ureter, and a maximum of 20 W should be used in kidney in presence of irrigation.
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Litotripsia por Láser , Litotripsia por Láser/métodos , Litotripsia por Láser/instrumentación , Humanos , Calor , Cálices Renales , Irrigación Terapéutica/métodosRESUMEN
PURPOSE: Investigating the performance of the new Dophi™ M150E Microwave Ablation System, in terms of temperature distribution, ablation size and shape, reproducibility. MATERIALS AND METHODS: The Dophi™ M150E Microwave Ablation System was tested on ex vivo liver, lung and kidney, at 6 different settings of time, power and number of MW antennas (single antenna: 50 and 100 W at 5 and 10 min; double antenna: 75 W at 5 and 10 min). The temperature distribution was recorded by Fiber Bragg Grating sensors, placed at different distances from the antennas. The ablation axes were measured and the sphericity index was calculated. RESULTS: The standard deviation of ablation axes was < 5 mm, except at the highest energy and time setting for the lung. A maximum temperature rise of ~ 80 °C was measured. The measured ablation axes are overall comparable with the manufacture's values, especially at lower power and with one MW antenna (average maximum difference is 7 mm). The mean sphericity index of 0.95, 0.79 and 0.9 was obtained for the liver, lung and kidney, respectively, with a single antenna. With double antenna setup, the sphericity index was closer to 1 when 75 W for 10 min were used. CONCLUSIONS: Dophi™ M150E allows good reproducibility of ablation axes for all cases except in the lung at the highest energy level. With one antenna, an almost spherical ablation area for the liver and kidney was obtained. Using double antenna results in more homogeneous temperature distribution within the tissue compared to single antenna.
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Hyperspectral imaging (HSI) is gaining increasing relevance in medicine, with an innovative application being the intraoperative assessment of the outcome of laser ablation treatment used for minimally invasive tumor removal. However, the high dimensionality and complexity of HSI data create a need for end-to-end image processing workflows specifically tailored to handle these data. This study addresses this challenge by proposing a multi-stage workflow for the analysis of hyperspectral data and allows investigating the performance of different components and modalities for ablation detection and segmentation. To address dimensionality reduction, we integrated principal component analysis (PCA) and t-distributed stochastic neighbor embedding (t-SNE) to capture dominant variations and reveal intricate structures, respectively. Additionally, we employed the Faster Region-based Convolutional Neural Network (Faster R-CNN) to accurately localize ablation areas. The two-stage detection process of Faster R-CNN, along with the choice of dimensionality reduction technique and data modality, significantly influenced the performance in detecting ablation areas. The evaluation of the ablation detection on an independent test set demonstrated a mean average precision of approximately 0.74, which validates the generalization ability of the models. In the segmentation component, the Mean Shift algorithm showed high quality segmentation without manual cluster definition. Our results prove that the integration of PCA, t-SNE, and Faster R-CNN enables improved interpretation of hyperspectral data, leading to the development of reliable ablation detection and segmentation systems.
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Imágenes Hiperespectrales , Terapia por Láser , Aprendizaje Automático , Terapia por Láser/métodos , Imágenes Hiperespectrales/métodos , Humanos , Redes Neurales de la Computación , Procesamiento de Imagen Asistido por Computador/métodos , Análisis de Componente PrincipalRESUMEN
Introduction: Photodynamic Therapy (PDT) is a promising, minimally invasive treatment for cancer with high immunostimulatory potential, no reported drug resistance, and reduced side effects. Indocyanine Green (ICG) has been used as a photosensitizer (PS) for PDT, although its poor stability and low tumor-target specificity strongly limit its efficacy. To overcome these limitations, ICG can be formulated as a tumor-targeting nanoparticle (NP). Methods: We nanoformulated ICG into recombinant heavy-ferritin nanocages (HFn-ICG). HFn has a specific interaction with transferrin receptor 1 (TfR1), which is overexpressed in most tumors, thus increasing HFn tumor tropism. First, we tested the properties of HFn-ICG as a PS upon irradiation with a continuous-wave diode laser. Then, we evaluated PDT efficacy in two breast cancer (BC) cell lines with different TfR1 expression levels. Finally, we measured the levels of intracellular endogenous heavy ferritin (H-Fn) after PDT treatment. In fact, it is known that cells undergoing ROS-induced autophagy, as in PDT, tend to increase their ferritin levels as a defence mechanism. By measuring intracellular H-Fn, we verified whether this interplay between internalized HFn and endogenous H-Fn could be used to maximize HFn uptake and PDT efficacy. Results: We previously demonstrated that HFn-ICG stabilized ICG molecules and increased their delivery to the target site in vitro and in vivo for fluorescence guided surgery. Here, with the aim of using HFn-ICG for PDT, we showed that HFn-ICG improved treatment efficacy in BC cells, depending on their TfR1 expression. Our data revealed that endogenous H-Fn levels were increased after PDT treatment, suggesting that this defence reaction against oxidative stress could be used to enhance HFn-ICG uptake in cells, increasing treatment efficacy. Conclusion: The strong PDT efficacy and peculiar Trojan horse-like mechanism, that we revealed for the first time in literature, confirmed the promising application of HFn-ICG in PDT.
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Neoplasias de la Mama , Verde de Indocianina , Nanopartículas , Fotoquimioterapia , Fármacos Fotosensibilizantes , Femenino , Humanos , Antígenos CD/metabolismo , Apoferritinas/química , Neoplasias de la Mama/terapia , Neoplasias de la Mama/tratamiento farmacológico , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Ferritinas/química , Verde de Indocianina/química , Verde de Indocianina/farmacología , Verde de Indocianina/uso terapéutico , Células MCF-7 , Nanopartículas/química , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/química , Receptores de Transferrina/metabolismoRESUMEN
Thermal therapies treat tumors by means of heat, greatly reducing pain, post-operation complications, and cost as compared to traditional methods. Yet, effective tools to avoid under- or over-treatment are mostly needed, to guide surgeons in laparoscopic interventions. In this work, we investigated the temperature-dependent optical signatures of ex-vivo calf brain, lung, and heart tissues based on the reduced scattering and absorption coefficients in the near-infrared spectral range (657 to 1107 nm). These spectra were measured by time domain diffuse optics, applying a step-like spatially homogeneous thermal treatment at 43 °C, 60 °C, and 80 °C. We found three main increases in scattering spectra, possibly due to the denaturation of collagen, myosin, and the proteins' secondary structure. After 75 °C, we found the rise of two new peaks at 770 and 830 nm in the absorption spectra due to the formation of a new chromophore, possibly related to hemoglobin or myoglobin. This research marks a significant step forward in controlling thermal therapies with diffuse optical techniques by identifying several key markers of thermal damage. This could enhance the ability to monitor and adjust treatment in real-time, promising improved outcomes in tumor therapy.
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Lower-limb rehabilitation exoskeletons offer a transformative approach to enhancing recovery in patients with movement disorders affecting the lower extremities. This comprehensive systematic review delves into the literature on sensor technologies and the control strategies integrated into these exoskeletons, evaluating their capacity to address user needs and scrutinizing their structural designs regarding sensor distribution as well as control algorithms. The review examines various sensing modalities, including electromyography (EMG), force, displacement, and other innovative sensor types, employed in these devices to facilitate accurate and responsive motion control. Furthermore, the review explores the strengths and limitations of a diverse array of lower-limb rehabilitation-exoskeleton designs, highlighting areas of improvement and potential avenues for further development. In addition, the review investigates the latest control algorithms and analysis methods that have been utilized in conjunction with these sensor systems to optimize exoskeleton performance and ensure safe and effective user interactions. By building a deeper understanding of the diverse sensor technologies and monitoring systems, this review aims to contribute to the ongoing advancement of lower-limb rehabilitation exoskeletons, ultimately improving the quality of life for patients with mobility impairments.
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This work presents the dual-phase lag-based non-Fourier bioheat transfer model of brain tissue subjected to interstitial laser ablation. The finite element method has been utilized to predict the brain tissue's temperature distributions and ablation volumes. A sensitivity analysis has been conducted to quantify the effect of variations in the input laser power, treatment time, laser fiber diameter, laser wavelength, and non-Fourier phase lags. Notably, in this work, the temperature-dependent thermal properties of brain tissue have been considered. The developed model has been validated by comparing the temperature obtained from the numerical and ex vivo brain tissue during interstitial laser ablation. The ex vivo brain model has been further extended to in vivo settings by incorporating the blood perfusion effects. The results of the systematic analysis highlight the importance of considering temperature-dependent thermal properties of the brain tissue, non-Fourier behavior, and microvascular perfusion effects in the computational models for accurate predictions of the treatment outcomes during interstitial laser ablation, thereby minimizing the damage to surrounding healthy tissue. The developed model and parametric analysis reported in this study would assist in a more accurate and precise prediction of the temperature distribution, thus allowing to optimize the thermal dosage during laser therapy in the brain.
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Hipertermia Inducida , Terapia por Láser , Hipertermia Inducida/métodos , Rayos Láser , Temperatura , Perfusión , Modelos Biológicos , CalorRESUMEN
Optical sensors and sensing technologies are playing a more and more important role in our modern world. From micro-probes to large devices used in such diverse areas like medical diagnosis, defence, monitoring of industrial and environmental conditions, optics can be used in a variety of ways to achieve compact, low cost, stand-off sensing with extreme sensitivity and selectivity. Actually, the challenges to the design and functioning of an optical sensor for a particular application requires intimate knowledge of the optical, material, and environmental properties that can affect its performance. This roadmap on optical sensors addresses different technologies and application areas. It is constituted by twelve contributions authored by world-leading experts, providing insight into the current state-of-the-art and the challenges their respective fields face. Two articles address the area of optical fibre sensors, encompassing both conventional and specialty optical fibres. Several other articles are dedicated to laser-based sensors, micro- and nano-engineered sensors, whispering-gallery mode and plasmonic sensors. The use of optical sensors in chemical, biological and biomedical areas is discussed in some other papers. Different approaches required to satisfy applications at visible, infrared and THz spectral regions are also discussed.
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BACKGROUND: Needle-based procedures, such as fine needle aspiration and thermal ablation, are often applied for thyroid nodule diagnosis and therapeutic purposes, respectively. With blood vessels and nerves nearby, these procedures can pose risks in damaging surrounding critical structures. PURPOSE: The development and validation of innovative strategies to manage these risks require a test object with well-characterized physical properties. For this work, we focus on the application of ultrasound-guided thermal radiofrequency ablation. METHODS: We have developed a single-use anthropomorphic phantom mimicking the thyroid and surrounding anatomical and physiological structures that are relevant to ultrasound-guided thermal ablation. The phantom was composed of a mixture of polyacrylamide, water, and egg white extract and was cast using molds in multiple steps. The thermal, acoustical, and electrical characteristics were experimentally validated. The ablation zones were analyzed via non-destructive T2 -weighted magnetic resonance imaging scans utilizing the relaxometry changes of coagulated egg albumen, and the temperature distribution was monitored using an array of fiber Bragg grating sensors. RESULTS: The physical properties of the phantom were verified both on ultrasound as well as in terms of the phantom response to thermal ablation. The final temperature achieved (92°C), the median percentage of the nodule ablated (82.1%), the median volume ablated outside the nodule (0.8 mL), and the median number of critical structures affected (0) were quantified. CONCLUSION: An anthropomorphic phantom that can provide a realistic model for development and training in ultrasound-guided needle-based thermal interventions for thyroid nodules has been presented.
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Ablación por Catéter , Nódulo Tiroideo , Humanos , Nódulo Tiroideo/diagnóstico por imagen , Nódulo Tiroideo/cirugía , Fantasmas de Imagen , Ablación por Catéter/métodos , Ultrasonografía Intervencional , Resultado del TratamientoRESUMEN
In the present work, we implemented a computational framework of in vivo gold nanorod (GNR)-enhanced photothermal therapy (PTT) for tumor treatment. The temperature-dependent thermophysical properties of biological tissue and the optical properties of both GNRs and the biological media were included. The latter were modulated during the treatment simulation to account for their variation, from the native to the coagulated state. The contribution of tissue injury-dependent blood perfusion was also considered. The developed model allowed for the estimation of temperature distribution during the photothermal procedure at different procedural settings and amounts of GNRs embedded in the tumor region (i.e., 12.5 µg, 25 µg, and 50 µg). Furthermore, the influence of GNRs on thermal injury, estimated with different damage models, was assessed. The inclusion of GNRs in the tumor entailed an increment of maximum tissue temperature, and faster heating kinetics, as witnessed by the lower time needed to reach complete thermal damage at the tumor center. The percentage of tumor thermal damage evaluated at the end of the simulated treatment was 48%, 69%, and 90%, for PTT in the presence of 12.5 µg, 25 µg, and 50 µg of GNRs, respectively.Clinical Relevance-This establishes that simulation-based tools, modeling the tissue properties variation during the photothermal treatment, can serve as promising preplanning platforms for nanoparticle-assisted light therapies.
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Nanotubos , Neoplasias , Humanos , Terapia Fototérmica , Oro/uso terapéutico , Fototerapia , Neoplasias/tratamiento farmacológicoRESUMEN
This work is a step towards the analysis of the effect of different laser applicator tips used for laser ablation of liver for in vivo experiments. As the thermal outcome of this minimally invasive treatment for tumors depends upon the interaction between the tissue and the light, the emission pattern of the laser applicator has a key role in the shape and size of the final treated region. Hence, we have compared two different laser applicators: a bare tip fiber (emitting light from the tip and forward) and a diffuser tip fiber (emitting light at 360° circumferentially from the side of the fiber). The experiments have been carried out percutaneously in a preclinical scenario (anesthetized pigs), under computed tomography (CT) guidance. The thermal effects of the two applicators have been assessed in terms of real-time temperature distribution, by means of an array of 40 fiber Bragg grating (FBG) sensors, and in terms of cavitation and ablation volumes, measured through CT post-temperature due to breathing motion has been analyzed and filtered out. Results show that the maximum temperature reached 50.5 °C for the bare tip fiber experiment (measured at 6.24 mm distance from the applicator) and 60.9 °C for the diffuser tip fiber experiment (measured at 5.23 mm distance from the applicator). The diffuser tip fiber allowed to achieve a more symmetrical heat distribution than the bare tip fiber, and without cavitation volume.Clinical Relevance-This work shows the analysis of the thermal effects of different laser fiber tips to improve laser ablation treatment. The results obtained in the preclinical scenario well represent the expected clinical outcome in the treatment of hepatic tumors. Moreover, these findings can be applied to other fields in which laser ablation is the optimal therapeutic choice, such as neurosurgery.
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Terapia por Láser , Neoplasias , Porcinos , Animales , Rayos Láser , Hígado/diagnóstico por imagen , Hígado/cirugía , Neoplasias/patología , LuzRESUMEN
In this work, we devised the first characterization of the optical and thermal properties of ex vivo cardiac tissue as a function of different selected temperatures, ranging from room temperature to hyperthermic and ablative temperatures. The broadband (i.e., from 650 nm to 1100 nm) estimation of the optical properties, i.e., absorption coefficient (µa) and reduced scattering coefficient $({\mu ^{\prime}}_s)$, was performed by means of time-domain diffuse optics. Besides, the measurement of the thermal properties was based on the transient hot-wire technique, employing a dual-needle probe to estimate the tissue thermal conductivity (k), thermal diffusivity (α), and volumetric heat capacity (Cv). Increasing the tissue temperature led to variations in the spectral characteristics of µa (e.g., the redshift of the 780 nm peak, the rise of a new peak at 840 nm, and the formation of a valley at 900 nm). Moreover, an increase in the values of ${\mu ^{\prime}}_s$ was assessed as tissue temperature raised (e.g., for 800 nm, at 25 °C ${\mu ^{\prime}}_s = 9.8{\text{ c}}{{\text{m}}^{{\text{ - 1}}}}$, while at 77 °C ${\mu ^{\prime}}_s = 29.1{\text{ c}}{{\text{m}}^{{\text{ - 1}}}}$). Concerning the thermal properties characterization, k was almost constant in the selected temperature interval. Conversely, α and Cv were subjected to an increase and a decrease with temperature, respectively; thus, they registered values of 0.190 mm2/s and 3.03 MJ/(m3â¢K) at the maximum investigated temperature (79 °C), accordingly.Clinical Relevance- The experimentally obtained optical and thermal properties of cardiac tissue are useful to improve the accuracy of simulation-based tools for thermal therapy planning. Furthermore, the measured properties can serve as a reference for the realization of tissue-mimicking phantoms for medical training and testing of medical instruments.
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Hipertermia Inducida , Temperatura , Calor , Óptica y Fotónica , Conductividad TérmicaRESUMEN
Hydrogels are 3D cross-linked networks of polymeric chains designed to be used in the human body. Nowadays they find widespread applications in the biomedical field and are particularly attractive as drug delivery vectors. However, despite many good results, their release performance is sometimes very quick and uncontrolled, being forced by the high in vivo clearance of body fluids. In this direction, the development of novel responsive nanomaterials promises to overcome the drawbacks of common hydrogels, inducing responsive properties in three-dimensional polymeric devices. In this study, we synthesized and then loaded gold nanorods (Au NRs) within an agarose-carbomer (AC)-based hydrogel obtained from a microwave-assisted polycondensation reaction between carbomer 974P and agarose. The photothermal effect of the composite device was quantified in terms of maximum temperature and spatial-temporal temperature distribution, also during consecutive laser irradiations. This work shows that composite Au NRs loaded within AC hydrogels can serve as a stable photothermal treatment agent with enhanced photothermal efficiency and good thermal stability after consecutive laser irradiations. These results confirm that the composite system produced can exhibit an enhanced thermal effect under NIR laser irradiation, which is expected to lead to great therapeutic advantages for the localized treatment of different diseases.
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This experimental study aimed to characterize the thermal properties of ex vivo porcine and bovine kidney tissues in steady-state heat transfer conditions in a wider thermal interval (23.2-92.8 °C) compared to previous investigations limited to 45 °C. Thermal properties, namely thermal conductivity (k) and thermal diffusivity (α), were measured in a temperature-controlled environment using a dual-needle probe connected to a commercial thermal property analyzer, using the transient hot-wire technique. The estimation of measurement uncertainty was performed along with the assessment of regression models describing the trend of measured quantities as a function of temperature to be used in simulations involving heat transfer in kidney tissue. A direct comparison of the thermal properties of the same tissue from two different species, i.e., porcine and bovine kidney tissues, with the same experimental transient hot-wire technique, was conducted to provide indications on the possible inter-species variabilities of k and α at different selected temperatures. Exponential fitting curves were selected to interpolate the measured values for both porcine and bovine kidney tissues, for both k and α. The results show that the k and α values of the tissues remained rather constant from room temperature up to the onset of water evaporation, and a more marked increase was observed afterward. Indeed, at the highest investigated temperatures, i.e., 90.0-92.8 °C, the average k values were subject to 1.2- and 1.3-fold increases, compared to their nominal values at room temperature, in porcine and bovine kidney tissue, respectively. Moreover, at 90.0-92.8 °C, 1.4- and 1.2-fold increases in the average values of α, compared to baseline values, were observed for porcine and bovine kidney tissue, respectively. No statistically significant differences were found between the thermal properties of porcine and bovine kidney tissues at the same selected tissue temperatures despite their anatomical and structural differences. The provided quantitative values and best-fit regression models can be used to enhance the accuracy of the prediction capability of numerical models of thermal therapies. Furthermore, this study may provide insights into the refinement of protocols for the realization of tissue-mimicking phantoms and the choice of tissue models for bioheat transfer studies in experimental laboratories.
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Calor , Hipertermia Inducida , Animales , Bovinos , Porcinos , Temperatura , Conductividad Térmica , RiñónRESUMEN
Laser-induced thermotherapy has shown promising potential for the treatment of unresectable primary pancreatic ductal adenocarcinoma tumors. Nevertheless, heterogeneous tumor environment and complex thermal interaction phenomena that are established under hyperthermic conditions can lead to under/over estimation of laser thermotherapy efficacy. Using numerical modeling, this paper presents an optimized laser setting for Nd:YAG laser delivered by a bare optical fiber (300 µm in diameter) at 1064 nm working in continuous mode within a power range of 2-10 W. For the thermal analysis, patient-specific 3D models were used, consisting of tumors in different portions of the pancreas. The optimized laser power and time for ablating the tumor completely and producing thermal toxic effects on the possible residual tumor cells beyond the tumor margins were found to be 5 W for 550 s, 7 W for 550 s, and 8 W for 550 s for the pancreatic tail, body, and head tumors, respectively. Based on the results, during the laser irradiation at the optimized doses, thermal injury was not evident either in the 15 mm lateral distances from the optical fiber or in the nearby healthy organs. The present computational-based predictions are also in line with the previous ex vivo and in vivo studies, hence, they can assist in the estimation of the therapeutic outcome of laser ablation for pancreatic neoplasms prior to clinical trials.
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Carcinoma Ductal Pancreático , Hipertermia Inducida , Terapia por Láser , Láseres de Estado Sólido , Neoplasias Pancreáticas , Humanos , Hipertermia Inducida/métodos , Terapia por Láser/métodos , Neoplasias Pancreáticas/cirugía , Carcinoma Ductal Pancreático/cirugía , Neoplasias PancreáticasRESUMEN
The extensive use of antibiotics has become a serious concern due to certain deficiencies in wastewater facilities, their resistance to removal, and their toxic effects on the natural environment. Therefore, substantial attention has been given to the detection of antibiotics because of their potential detriment to the ecosystem and human health. In the present study, a novel design of indium tin oxide (ITO) coated U-shaped fiber optic lossy mode resonance (LMR) biosensor is presented for the sensitive detection of the antibiotic ciprofloxacin (CIP). The performance of the designed U-shaped LMR sensor is characterized in terms of its sensitivity, full width at half maximum (FWHM), the figure of merit (FOM), and the limit of detection (LOD). For the proposed U-shaped LMR sensing probe, the various crucial factors such as the thickness (d) of the ITO layer, sensing region length (L), and bending radius (R) are optimized. The thickness of the ITO layer is optimized in such a way that two LMR curves are observed in the transmission spectrum and, thereafter, the performance parameters are evaluated for each LMR. It is observed that the designed U-shaped LMR sensor with optimized parameters shows an approximately seven-fold enhancement in sensitivity compared to the straight-core fiber optic LMR sensor. The numerical results revealed that the designed U-shaped fiber optic LMR biosensor can provide a maximum sensitivity of 17,209.9 nm/RIU with the highest FOM of 91.42 RIU-1, and LOD of 6.3 × 10-5 RIU for the detection of CIP hydrochloride in the concentration range of 0.001 to 0.029 molâdm-3. Thus, it is believed that the designed LMR biosensor can practically explore its potential use in environmental monitoring and biomedical applications and hence, opens a new window of opportunity for the researchers working in the field of U-shaped fiber optic LMR biosensing.
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Técnicas Biosensibles , Ciprofloxacina , Humanos , Antibacterianos , EcosistemaRESUMEN
Hyperspectral imaging (HSI) is a non-invasive, contrast-free optical-based tool that has recently been applied in medical and basic research fields. The opportunity to use HSI to identify exogenous tumor markers in a large field of view (LFOV) could increase precision in oncological diagnosis and surgical treatment. In this study, the anti-high mobility group B1 (HMGB1) labeled with Alexa fluorophore (647 nm) was used as the target molecule. This is the proof-of-concept of HSI's ability to quantify antibodies via an in vitro setting. A first test was performed to understand whether the relative absorbance provided by the HSI camera was dependent on volume at a 1:1 concentration. A serial dilution of 1:1, 10, 100, 1000, and 10,000 with phosphatase-buffered saline (PBS) was then used to test the sensitivity of the camera at the minimum and maximum volumes. For the analysis, images at 640 nm were extracted from the hypercubes according to peak signals matching the specificities of the antibody manufacturer. The results showed a positive correlation between relative absorbance and volume (r = 0.9709, p = 0.0013). The correlation between concentration and relative absorbance at min (1 µL) and max (20 µL) volume showed r = 0.9925, p < 0.0001, and r = 0.9992, p < 0.0001, respectively. These results demonstrate the HSI potential in quantifying HMGB1, hence deserving further studies in ex vivo and in vivo settings.
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For early-stage cancer detection, a novel design of graphene-antimonene-coated uniform-waist tapered fiber optic surface plasmon resonance (SPR) biosensor is demonstrated. The proposed optical biosensor outperforms over a wide range of refractive index (RI) variations including biological solutions and is designed to detect various cancerous cells in the human body whose RIs are in the range of 1.36-1.4. Here, antimonene is used to enhance the performance of the designed SPR sensor for sensing cancer analytes because of its high binding energy toward adsorption of biomolecules and large active surface area. The design and analysis of the sensor are done with the help of a transfer matrix method-based simulation platform, and the effect of the taper ratio is also studied. The performance of the proposed SPR biosensor is evaluated with performance parameters such as sensitivity, full width at half maximum, detection accuracy (DA), figure of merit (FOM), and limit of detection (LOD). The numerical results show that the designed sensor is able to provide a sensitivity of 7.3465, 10.9250, 11.8914, and 15.2414 µm/RIU, respectively, for sensing skin, cervical, blood, and adrenal gland cancer with a maximum FOM of 131.1525 RIU-1, DA of 14.2126 µm-1, and LOD of 7.2 × 10-5 RIU. Based on the derived results, the authors believe that the designed SPR sensor could practically find its potential applications in the field of medical science for the early-stage diagnosis of cancer and hence, opens a new window in the field of biosensing.