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1.
Int J Biol Macromol ; 251: 126331, 2023 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-37579899

RESUMO

One of the most attractive approaches in biomedicine and pharmacy is the application of multifunctional materials. The mesoporous structure of clinoptilolite (CZ) absorbs various types of substances and can be used as a model for studying the carriers for targeted drug delivery with controlled release. CZ-dye composites are fabricated by incorporation into clinoptilolite pores commonly used dyes, aluminum phthalocyanine, zinc porphine, and hypericin. We examined and compared the effect of pure dyes and CZ-dye composites on insulin amyloidogenesis. The formation of insulin amyloid fibrils and the disassembly of preformed fibrils is significantly affected by any of the three compounds, however, the strongest effect is observed for aluminum phthalocyanine indicating a structurally-dependent anti-amyloidogenic activity of the dyes. The incorporation of dyes into CZ particles resulted in enhanced anti-amyloidogenic activity in comparison to pure CZ particles. The cell metabolic activity, biocompatibility and fluorescence biodistribution of the dyes entrapped in the composites were tested in vitro (U87 MG cells) and in vivo in the quail chorioallantoic membrane model. Considering the photoactive properties of the dyes used, we assume their applicability in photodiagnostics and photodynamic therapy. It can also be expected that their anti-amyloidogenic potential can be enhanced by photodynamic effect.

2.
Sci Rep ; 11(1): 5528, 2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33750868

RESUMO

Magnetic nano/micro-particles based on clinoptilolite-type of natural zeolite (CZ) were fabricated and were expected to act as carriers for controlled drug delivery/release, imaging and local heating in biological systems. Adsorption of rhodamine B, sulfonated aluminum phthalocyanine and hypericin by magnetic CZ nano/micro-particles was investigated, as was the release of hypericin. Using an alternating magnetic field, local temperature increase by 10 °C in animal tissue with injected magnetic CZ particles was demonstrated. In addition, the CZ-based particles have been found to exhibit an anti-amyloidogenic effect on the amyloid aggregation of insulin and lysozyme in a dose- and temperature-dependent manner. Therefore, the mesoporous structure of CZ particles provided a unique platform for preparation of multifunctional magnetic and optical probes suitable for optical imaging, MRI, thermo- and phototherapy and as effective containers for controlled drug delivery. We concluded that magnetic CZ nano/micro-particles could be evaluated for further application in cancer hyperthermia therapy and as anti-amyloidogenic agents.


Assuntos
Hipertermia Induzida , Nanocompostos/química , Zeolitas/química , Preparações de Ação Retardada/síntese química , Preparações de Ação Retardada/química
3.
J Biomed Opt ; 23(9): 1-7, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29858548

RESUMO

Using multiphoton microscopy (MPM), we demonstrated that effective inducing of two-photon excited luminescence and second-harmonic generation signals in nano/microparticles of clinoptilolite type of zeolite (CZ) by femtosecond near-infrared laser excitation can be successfully utilized in multiphoton imaging of the drug adsorption processes. Adsorption of photodynamic active dyes (hypericin, chlorin e6, methylene blue, and fluorescein) and their release from CZ pores in the presence of biomolecules, such as collagen from bovine Achilles tendon, albumin, and hemoglobin, were investigated by absorption and fluorescence spectrometry. To quantify the experimental results on hypericin release, here we use a kinetic curves fitting approach and calculate hypericin release rates in different environments. This approach allows to compare various mathematical models and uses more parameters to better characterize drug release profiles. In addition, magnetic CZ particles were fabricated and proposed as a promising material for drug delivery and controlled release in biological systems. Optical spectrometry and MPM are effective approaches that may reveal potential of natural zeolites in controlled drug delivery and biomedical imaging.


Assuntos
Microscopia de Fluorescência por Excitação Multifotônica/métodos , Zeolitas/química , Zeolitas/farmacocinética , Tendão do Calcâneo/química , Adsorção , Animais , Antracenos , Bovinos , Colágeno/química , Corantes/análise , Corantes/farmacocinética , Nanopartículas de Magnetita/química , Perileno/análogos & derivados , Perileno/análise , Perileno/farmacocinética
4.
J Biophotonics ; 11(9): e201700338, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29388745

RESUMO

In this study, intravital multiphoton microscopy was used to quantitatively investigate hepatobiliary metabolism in chronic pathologies of the liver. Specifically, through the use of the probe molecule 6-carboxyfluorescein diacetate, the effects of liver fibrosis, fatty liver, and hepatocellular carcinoma on the metabolic capabilities of mouse liver were investigated. After the acquisition of time-lapse images, a first order kinetic model was used to calculate rate constant resolved images of various pathologies. It was found that the ability of the liver to metabolically process the probe molecules varies among different pathologies, with liver fibrosis and fatty liver disease negatively impacted the uptake, processing, and excretion of molecules. The approach demonstrated in this work allows the study of the response of hepatic functions to different pathologies in real time and is useful for studying processes such as pharmacokinetics through direct optical imaging.


Assuntos
Sistema Biliar/metabolismo , Hepatopatias/diagnóstico por imagem , Hepatopatias/metabolismo , Fígado/metabolismo , Imagem Óptica , Fótons , Animais , Sistema Biliar/diagnóstico por imagem , Doença Crônica , Fígado/diagnóstico por imagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL
5.
Sci Rep ; 7: 45503, 2017 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-28361968

RESUMO

Clinoptilolite type of zeolite (CZ) is a promising material for biomedicine and pharmaceutics due to its non-toxicity, thermal stability, expanded surface area, and exceptional ability to adsorb various atoms and organic molecules into micropores. Using multiphoton microscopy, we demonstrated that individual CZ particles produce two-photon excited luminescence and second harmonic generation signal at femtosecond laser excitation, and adsorb photo-dynamically active dyes such as hypericin and methylene blue. Furthermore, the release of hypericin from CZ pores in the presence of biomolecules is shown, and CZ can be considered as an effective material for drug delivery and controlled release in biological systems. The results may open new perspectives in application of CZ in biomedical imaging, and introducing of the optical approaches into the clinical environment.


Assuntos
Corantes/química , Azul de Metileno/química , Zeolitas/química , Adsorção , Preparações de Ação Retardada/química , Sistemas de Liberação de Medicamentos/métodos
6.
Biomed Opt Express ; 7(9): 3574-3584, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-27699121

RESUMO

Hepatobiliary metabolism is one of the major functions of the liver. However, little is known of the relationship between the physiological location of the hepatocytes and their metabolic potential. By the combination of time-lapse multiphoton microscopy and first order kinetic constant image analysis, the hepatocellular metabolic rate of the model compound 6-carboxyfluorescein diacetate (6-CFDA) is quantified at the single cell level. We found that the mouse liver can be divided into three zones, each with distinct metabolic rate constants. The sinusoidal uptake coefficients k1 of Zones 1, 2, and 3 are respectively 0.239 ± 0.077, 0.295 ± 0.087, and 0.338 ± 0.133 min-1, the apical excreting coefficients k2 of Zones 1, 2, and 3 are 0.0117 ± 0.0052, 0.0175 ± 0.0052, and 0.0332 ± 0.0195 min-1, respectively. Our results show not only the existence of heterogeneities in hepatobiliary metabolism, but they also show that Zone 3 is the main area of metabolism.

7.
J Biomed Opt ; 18(4): 046004, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23552636

RESUMO

Optical clearing (OC) is a promising method to overcome limitations in biomedical depth-resolved optical studies. Mechanisms of OC in purified bovine Achilles tendon, chicken skin, and chicken tendon were studied using time-lapsed, three-dimensional second harmonic generation (SHG) and two-photon fluorescence microscopic imaging. Quantified nonlinear optical measurements allowed temporal separation of two processes in collagen OC with glycerol. The first one is a fast process of tissue dehydration accompanied with collagen shrinkage and the second relatively slow process is glycerol penetration into the interfibrillar space of collagen alongside with CF swelling. The use of 50% glycerol induced less-expressed OC via partial substitution of water molecules with glycerol molecules. We also found that phosphate-buffered saline- and glycerol-treatments were reversible, and fiber morphology and SHG signal intensity were recovered after the removal of immersion agents. It was shown that tissue OC was a dynamic process and elucidation of its physical mechanisms may help choose optimal diagnostic, treatment, and modification regimes for collagen-based as well as other types of biomaterials.


Assuntos
Colágenos Fibrilares/química , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Imagem Óptica/métodos , Tendão do Calcâneo/química , Animais , Bovinos , Galinhas , Dessecação , Glicerol/química , Pele/química
8.
J Biomed Opt ; 18(3): 31102, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23174949

RESUMO

We discuss the recent advances in the development and applications of second-order susceptibility as a contrast mechanism in optical microscopy for biological tissues. We review nonlinear optical methods and approaches for differentiation of tissue structures and discrimination of normal and pathological skin tissues, which have been demonstrated for the potential use in clinical diagnosis. In addition, the potential of second-order susceptibility imaging, encompassing applications in differentiating various types of collagen molecules for clinical diagnosis, is demonstrated. Finally, we discuss future development and application of this technique.


Assuntos
Microscopia/métodos , Imagem Óptica/métodos , Pele/química , Animais , Colágeno/química , Humanos , Modelos Biológicos , Fenômenos Ópticos , Engenharia Tecidual
9.
J Biophotonics ; 5(10): 768-76, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22331651

RESUMO

In this work, we present a non-invasive approach to determine azimuth and elevation angles of collagen fibers capable of generating second harmonic signal. The azimuth angle was determined using the minimum of second harmonic generation (SHG) signal while rotating the plane of polarization of excitation light. The elevation angle was estimated from the ratio of the minimal SHG intensity to the intensity when laser polarization and fiber directions were parallel to each other using experimentally determined calibration curve. Pixel-resolution images of collagen fiber spatial orientation in tendon from bovine leg, chicken leg, and chicken skin were acquired using our approach of SHG polarization-resolved microscopy.


Assuntos
Colágeno , Microscopia/métodos , Fenômenos Ópticos , Animais , Bovinos
10.
Opt Express ; 18(23): 24037-47, 2010 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-21164751

RESUMO

Photophysical mechanisms of collagen photomodification (CFP) by the use of a 80 MHz, 780 nm femtosecond titanium-sapphire laser were investigated. Our observation that the decrease in collagen second harmonic generation and increase in two-photon autofluorescence intensity occurred primarily at sites where photoproducts were present suggested that the photoproducts may act to facilitate the CFP process. Laser power study of CFP indicated that the efficiency of the process depended on the sixth power of the laser intensity. Furthermore, it was demonstrated that CFP can be used for bending and cutting of collagen fibers and creating 3D patterns within collagen matrix with high precision (~2 µm).


Assuntos
Colágeno/química , Colágeno/efeitos da radiação , Lasers , Luz , Processos Fotoquímicos/efeitos da radiação , Animais , Cartilagem/anatomia & histologia , Bovinos , Galinhas , Derme/anatomia & histologia , Cinética , Ratos , Tendões/anatomia & histologia , Fatores de Tempo
11.
J Am Chem Soc ; 132(40): 14163-71, 2010 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-20857981

RESUMO

The conjugates of gold nanorods and the model drug, fluorescein isothiocyanate (FITC), embedded inside polyelectrolytes (GNRs/FITC@PLE) were synthesized to study the release kinetics of FITC under femtosecond near-infrared (NIR) laser irradiation. The optical and structural properties of GNRs/FITC@PLE conjugates before and after laser treatments were examined using UV-vis spectroscopy, confocal microscopy, and transmission electron microscopy (TEM). The release of FITC from the conjugates was induced by the heat generated from gold nanorods under laser irradiation. The concentration of released FITC was measured as the time of continuous and periodic laser irradiation was varied. Within 5 min of the laser exposure, the release rates of FITC exhibited zero-order and first-order kinetics under continuous and periodic irradiation, respectively. Furthermore, a drug release system was designed based on the conjugates of gold nanorods and the anticancer drug, paclitaxel (PTX), embedded inside polyelectrolytes (GNRs/PTX@PLE). The conjugates were applied for in vitro studies with breast cancer cells. The release of PTX from the conjugates was triggered by NIR laser irradiation, and the inhibition rates of the cells showed strong dependencies on the irradiation modes and time. The results suggested that the multiple releases of PTX from the conjugates can be controlled by laser irradiation within a long period of time. Our system holds great potential for future therapeutic applications on breast cancers.


Assuntos
Sistemas de Liberação de Medicamentos , Eletrólitos , Ouro , Raios Infravermelhos , Nanotubos , Farmacocinética
12.
J Biomed Opt ; 15(3): 036002, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20615004

RESUMO

Conventionally, liver fibrosis is diagnosed using histopathological techniques. The traditional method is time-consuming in that the specimen preparation procedure requires sample fixation, slicing, and labeling. Our goal is to apply multiphoton microscopy to efficiently image and quantitatively analyze liver fibrosis specimens bypassing steps required in histological preparation. In this work, the combined imaging modality of multiphoton autofluorescence (MAF) and second-harmonic generation (SHG) was used for the qualitative imaging of liver fibrosis of different METAVIR grades under label-free, ex vivo conditions. We found that while MAF is effective in identifying cellular architecture in the liver specimens, it is the spectrally distinct SHG signal that allows the characterization of the extent of fibrosis. We found that qualitative SHG imaging can be used for the effective identification of the associated features of liver fibrosis specimens graded METAVIR 0 to 4. In addition, we attempted to associate quantitative SHG signal to the different METAVIR grades and found that an objective determination of the extent of disease progression can be made. Our approach demonstrates the potential of using multiphoton imaging in rapid classification of ex vivo liver fibrosis in the clinical setting and investigation of liver fibrosis-associated physiopathology in animal models in vivo.


Assuntos
Cirrose Hepática/patologia , Microscopia Acústica/métodos , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Processamento de Sinais Assistido por Computador , Análise de Variância , Progressão da Doença , Humanos , Imuno-Histoquímica , Cirrose Hepática/diagnóstico
13.
Biomed Opt Express ; 2(2): 218-30, 2010 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-21339868

RESUMO

Tissue glycation from diabetes and aging can result in complications such as renal failure, blindness, nerve damage and vascular diseases. In this work, we applied multiphoton microscopy for imaging and characterizing the extent of tissue glycation. The characteristic features of multiphoton autofluorescence (MPAF) and second harmonic generation (SHG) images as well as MPAF spectra of glycated bovine skin, cornea and aorta were acquired. The analysis of MPAF intensity change accompanying the glycation process shows that collagen is more responsive to the formation of autofluorescent advanced glycation endproducts (AGE) than elastic fibers. Changes in spectral features were also used to estimate the rate of glycation in tissues with intrinsic AF. Our study shows that multiphton imaging may be used for the in vitro investigation of the effects of tissue glycation and that this approach may be used for monitoring AGE formation in the clinical setting.

14.
J Biomed Opt ; 14(5): 054003, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19895105

RESUMO

We used the combination of multiphoton autofluorescence (MAF), forward second-harmonic generation (FWSHG), and backward second-harmonic generation (BWSHG) imaging for the qualitative and quantitative characterization of thermal damage of ex vivo bovine cornea. We attempt to characterize the structural alterations by qualitative MAF, FWSHG, and BWSHG imaging in the temperature range of 37 to 90 degrees C. In addition to measuring the absolute changes in the three types of signals at the stromal surface, we also performed image correlation analysis between FWSHG and BWSHG and demonstrate that with increasing thermal damage, image correlation between FWSHG and BWSHG significantly increases. Our results show that while MAF and BWSHG intensities may be used as preliminary indicators of the extent of corneal thermal damage, the most sensitive measures are provided by the decay in FWSHG intensity and the convergence of FWSHG and BWSHG images.


Assuntos
Córnea/patologia , Lesões da Córnea , Queimaduras Oculares/patologia , Aumento da Imagem/métodos , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Técnica de Subtração , Animais , Bovinos , Técnicas In Vitro , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
15.
J Biomed Opt ; 14(4): 044034, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19725745

RESUMO

We utilize multiphoton microscopy for the label-free diagnosis of noncancerous, lung adenocarcinoma (LAC), and lung squamous cell carcinoma (SCC) tissues from humans. Our results show that the combination of second-harmonic generation (SHG) and multiphoton excited autofluorescence (MAF) signals may be used to acquire morphological and quantitative information in discriminating cancerous from noncancerous lung tissues. Specifically, noncancerous lung tissues are largely fibrotic in structure, while cancerous specimens are composed primarily of tumor masses. Quantitative ratiometric analysis using MAF to SHG index (MAFSI) shows that the average MAFSI for noncancerous and LAC lung tissue pairs are 0.55+/-0.23 and 0.87+/-0.15, respectively. In comparison, the MAFSIs for the noncancerous and SCC tissue pairs are 0.50+/-0.12 and 0.72+/-0.13, respectively. Our study shows that nonlinear optical microscopy can assist in differentiating and diagnosing pulmonary cancer from noncancerous tissues.


Assuntos
Adenocarcinoma/patologia , Algoritmos , Inteligência Artificial , Interpretação de Imagem Assistida por Computador/métodos , Neoplasias Pulmonares/patologia , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Reconhecimento Automatizado de Padrão/métodos , Carcinoma de Células Escamosas , Diagnóstico Diferencial , Humanos , Aumento da Imagem/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
Biophys J ; 97(4): 1198-205, 2009 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-19686668

RESUMO

The purpose of this study was to image and quantify the structural changes of corneal edema by second harmonic generation (SHG) microscopy. Bovine cornea was used as an experimental model to characterize structural alterations in edematous corneas. Forward SHG and backward SHG signals were simultaneously collected from normal and edematous bovine corneas to reveal the morphological differences between them. In edematous cornea, both an uneven expansion in the lamellar interspacing and an increased lamellar thickness in the posterior stroma (depth > 200 microm) were identified, whereas the anterior stroma, composed of interwoven collagen architecture, remained unaffected. Our findings of heterogeneous structural alteration at the microscopic scale in edematous corneas suggest that the strength of collagen cross-linking is heterogeneous in the corneal stroma. In addition, we found that qualitative backward SHG collagen fiber imaging and depth-dependent signal decay can be used to detect and diagnose corneal edema. Our work demonstrates that SHG imaging can provide morphological information for the investigation of corneal edema biophysics, and may be applied in the evaluation of advancing corneal edema in vivo.


Assuntos
Córnea/ultraestrutura , Edema da Córnea/patologia , Interpretação de Imagem Assistida por Computador/métodos , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Animais , Bovinos , Técnicas In Vitro
17.
J Biomed Opt ; 13(4): 044023, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19021351

RESUMO

The effects of off-axis optical aberration in multiphoton microscopy and the resulting lateral and axial image inhomogeneity are investigated. The lateral inhomogeneity of the scanning field is demonstrated by second harmonic generation (SHG) imaging of fasciae and two-photon fluorescence (TPF) microscopy of thin fluorescent samples. Furthermore, refractive index mismatch-caused intensity attenuation of the TPF signal at central and peripheral regions of the scanning frame is measured using homogeneous 10-microM sulforhodamine B samples with refractive indexes of 1.33 and around 1.465. In addition to characterizing image field convexity, we also found that image resolution degrades away from the optical axis. These effects need to be accounted for in both qualitative and quantitative multiphoton imaging applications.


Assuntos
Artefatos , Fáscia/citologia , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Animais , Anisotropia , Galinhas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
18.
J Biomed Opt ; 13(5): 050502, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19021374

RESUMO

The fruit fly Drosophila melanogaster is one of the most valuable organisms in studying genetics and developmental biology. To gain insight into Drosophila development, we successfully acquired label-free, in vivo images of both developing muscles and internal organs in a stage 2 larva using the minimally invasive imaging modality of multiphoton autofluorescence (MAF) and second harmonic generation (SHG) microscopy. We found that although MAF is useful in identifying structures such as the digestive system, trachea, and intestinal track, it is the SHG signal that allowed the investigation of the muscular architecture within the developing larva. Our results suggest that multiphoton microscopy is a powerful in vivo, label-free imaging technique to examine Drosophila physiology and may be used for developmental studies.


Assuntos
Drosophila melanogaster/citologia , Aumento da Imagem/métodos , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Animais , Larva , Coloração e Rotulagem
19.
Opt Express ; 16(11): 7958-68, 2008 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-18545505

RESUMO

In this work, we investigate the non-ablative, non-thermal photo-modification of collagen fibers by femtosecond Ti:Sa laser. The effect was induced and simultaneously registered during the repetitive laser scanning of type I collagen (rat tail and bovine Achilles' tendon), and bovine cornea. An irreversible increase in two-photon autofluorescence and a decrease in second harmonic generation intensities were associated with the collagen femtosecond laser photo-modification. Confocal spectral imaging revealed the formation of new fluorescent species. Controllable nonlinear photo-modification of collagen fibers and bovine cornea with approximately 2 microm spatial resolution was demonstrated.


Assuntos
Colágenos Fibrilares/química , Colágenos Fibrilares/efeitos da radiação , Lasers , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Colágenos Fibrilares/ultraestrutura , Doses de Radiação
20.
Opt Express ; 16(7): 5107-17, 2008 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-18542610

RESUMO

Large-area multiphoton laser scanning microscopy (LMLSM) can be applied in biology and medicine for high sensitivity and resolution tissue imaging. However, factors such as refractive index mismatch induced spherical aberration, emission/excitation absorption and scattering can result in axial intensity attenuation and lateral image heterogeneity, affecting both qualitative and quantitative image analysis. In this work, we describe an image correction algorithm to improve three-dimensional images in LMLSM. The method consists of multiplying the measured nonlinear signal by a three-dimensional correction factor, determined by the use of twophoton images of the appropriate specimens and specimen absorption and scattering properties at the excitation and emission wavelengths. The proposed methodology is demonstrated in correcting multiphoton images of objects imbedded in uniform fluorescent background, lung tissue, and Drosophila larva.


Assuntos
Algoritmos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Microscopia de Fluorescência por Excitação Multifotônica/métodos
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