scholarly journals Enhanced Photothermal and Photoacoustic Performance of Graphene Oxide in NIR-II Biowindow by Chemical Reduction

Photonics ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 2
Author(s):  
Xiaoye Su ◽  
Liantong Li ◽  
Dandan Cui ◽  
Wei Fang ◽  
Yujiao Shi
Keyword(s):  
Graphene Oxide ◽  
Rational Design ◽  
Near Infrared ◽  
Chemical Reduction ◽  
Black Body ◽  
Absorption Enhancement ◽  
Chemically Reduced Graphene Oxide ◽  
Novel Strategy

We report on a novel strategy for constructing graphene oxide nanomaterials with strongly enhanced photothermal (PT) and photoacoustic (PA) performance in the near-infrared (NIR)-II biowindow by chemical reduction. Optical spectra clearly reveal that obvious enhancement of optical absorption is observed in the whole NIR wideband from the NIR-I to NIR-II region for chemically reduced graphene oxide (CR-G) nanomaterials, which is mainly arising from the restoration of the electronic conjugation within the graphene oxide sheets and therefore inducing a black-body re-introduction effect of typical graphite-like materials. We experimentally synthesized CR-G samples with different degrees of reduction to demonstrate the efficiency of the proposed strategy. Experimental results show that the PT performance of the CR-G samples is greatly improved owing to the absorption enhancement by chemical reduction in the NIR-II biowindow. Furthermore, both in vitro and in vivo PA imaging of the CR-G samples with different degrees of reduction are performed to demonstrate their enhanced NIR-II PA performances. This work provides a feasible guidance for the rational design of graphene oxide nanomaterials with great potential for PT and PA applications in the NIR-II biowindow by chemical reduction.

Multifunctional graphene oxide for bioimaging: emphasis on biological research

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Do Won Hwang ◽  
Byung Hee Hong ◽  
Dong Soo Lee
Keyword(s):  
Graphene Oxide ◽  
Targeted Delivery ◽  
Near Infrared ◽  
Biological Research ◽  
Natural Interaction ◽  
Drug Delivery Carrier ◽  
Wide Range ◽  
Surface Enhanced Raman

AbstractGraphene oxide (GO) nanomaterials offer a wide range of bioimaging applicability. Almost complete quenching ability of fluorescence by GO and natural interaction of GO with single stranded nucleic acid made GO a useful and intriguing multifunctional nanoplatform both as a biosensor for in vitro microplate diagnostics and as a drug delivery carrier for targeted delivery. GO’s large surface area and strong near infrared absorbance contribute to enhancement of a therapeutic effect with abundant loading of drugs for possible photothermal and photodynamic therapy. Bioimaging capability of GO made it a good theranostic tool, while enabling tracing in vivo pharmacokinetics during concurrent treatment. Fluorescence, either signal on or off, Raman and surface-enhanced Raman scattering (SERs), photoacoustic, and radionuclide imaging modalities can be used for theranostic purposes using GO nanomaterials. In this review, we highlight current applications of GO for bioimaging that are classified into in vitro microplate, in vitro cellular and in vivo bioimaging.

Near-infrared emitting graphene quantum dots synthesized from reduced graphene oxide for in vitro/in vivo/ex vivo bioimaging applications

2D Materials ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 035013
Author(s):  
Md Tanvir Hasan ◽  
Bong Han Lee ◽  
Ching-Wei Lin ◽  
Ainsley McDonald-Boyer ◽  
Roberto Gonzalez-Rodriguez ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Near Infrared ◽  
Ex Vivo ◽  
Graphene Quantum Dots ◽  
Reduced Graphene

scholarly journals CCR2-Overexpressing Mesenchymal Stem Cells Targeting Damaged Liver Enhances Recovery of Acute Liver Failure

2021 ◽  
Author(s):  
Ruixuan Xu ◽  
Jiarou Shan ◽  
Beibei Ni ◽  
Lijie Pan ◽  
Guo Lv ◽  
...  
Keyword(s):  
Liver Failure ◽  
Acute Liver Failure ◽  
Chemokine Receptors ◽  
Near Infrared ◽  
Ex Vivo ◽  
Inflammatory Infiltration ◽  
In Vitro Expansion ◽  
Novel Strategy

Abstract Background: Mesenchymal stem cell (MSC) transplantation is emerging as a promising cell therapeutic strategy in acute liver failure (ALF) clinical research. The potency of MSCs to migrate and engraft into targeted lesions could largely determine their clinical efficacy, in which chemokine/receptor axes play a crucial role. Unfortunately, the downregulation of chemokine receptors expression after in vitro expansion results in a poor homing capacity of MSCs.Methods: By evaluating the chemokine expression profile in the liver of ALF patients and ALF mice, we found that CCL2 expression was highly upregulated in damaged livers, while the corresponding receptor, CCR2, was lacking in cultured MSCs. Thus, we genetically modified MSCs to overexpress CCR2 and investigated the targeted homing capacity and treatment efficacy of MSCCCR2 compared to those of the MSCvector control.Results: In vivo and ex vivo near-infrared fluorescence imaging showed that MSCCCR2 rapidly migrated and localized to injured livers in remarkably greater numbers following systemic infusion, and these cells were retained in liver lesions for a longer time than MSCvector. Furthermore, MSCCCR2 exhibited significantly enhanced efficacy in the treatment of ALF in mice, which was indicated by a dramatically improved survival rate, the alleviation of liver injury with reduced inflammatory infiltration, and hepatic apoptosis, and the promotion of liver regeneration.Conclusions: Altogether, these results indicate that CCR2 overexpression enhances the targeted migration of MSCs to damaged livers, improves their treatment effect, and may provide a novel strategy for improving the efficacy of cell therapy for ALF.

Fabrication of gold nanoshells for improvement of cell apoptosis and its application in photothermal cancer therapy

2020 ◽  
Vol 10 (8) ◽  
pp. 1204-1212
Author(s):  
Tengbiao Ma ◽  
Xue Guan ◽  
Dan Wu ◽  
Xinxia Wang ◽  
Yali Cui
Keyword(s):  
Cancer Therapy ◽  
Cell Apoptosis ◽  
Near Infrared ◽  
Biomedical Application ◽  
Treatment Method ◽  
Gold Nanoshells ◽  
Tunel Staining ◽  
Novel Strategy

For cancer diagnosis and therapeutics, we adopted a novel strategy and established a new approach by using transarterial administration of gold nanoshells on silica nanorattles (GSNs) for multifunctional biomedical application. The GSNs exhibit high biocompatibility and stability in vitro and in vivo. It was found that an arterial administration of GSNs showed six-fold higher efficiency than the venous method. In this study, we found that the system of using GSNs had a high near-infrared (NIR) absorbance and excellent photothermal transfer capability for cancer photothermal therapy (PTT) efficiently. More importantly, the GSN treatment method, involving interventional procedures and nanomaterials, showed great potential to promote tumor apoptosis in all research. Using CT imaging technology, we monitored the volume change of tumors and confirmed cell apoptosis by TUNEL staining and immunohistochemistry. Furthermore, arterial administration of GSNs combined with NIR irradiation was established, and the related proteins was examined by Western blotting. Caspase-3 and 9 showed an high expression level within tumor tissues. Finally, a comparative study of biodistribution and safety was performed in vivo, and the biocompatibility was carefully evaluated. This GSN-based method was ultimately shown to be a promising approach for cancer therapy.

scholarly journals 99mTc Labelling Strategies for the Development of Potential Nitroimidazolic Hypoxia Imaging Agents

Inorganics ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 128 ◽  
Author(s):  
Giglio ◽  
Rey
Keyword(s):  
Rational Design ◽  
Biological Properties ◽  
Fine Tuning ◽  
Oxidation States ◽  
Hypoxia Imaging ◽  
Biological Target ◽  
99Mtc Radiopharmaceuticals ◽  
99Mtc Labelling

Technetium-99m has a rich coordination chemistry that offers many possibilities in terms of oxidation states and donor atom sets. Modifications in the structure of the technetium complexes could be very useful for fine tuning the physicochemical and biological properties of potential 99mTc radiopharmaceuticals. However, systematic study of the influence of the labelling strategy on the “in vitro” and “in vivo” behaviour is necessary for a rational design of radiopharmaceuticals. Herein we present a review of the influence of the Tc complexes’ molecular structure on the biodistribution and the interaction with the biological target of potential nitroimidazolic hypoxia imaging radiopharmaceuticals presented in the literature from 2010 to the present. Comparison with the gold standard [18F]Fluoromisonidazole (FMISO) is also presented.

In vitro and in vivo characterization of graphene oxide coated porcine bone granules

Carbon ◽  
2016 ◽  
Vol 103 ◽  
pp. 291-298 ◽  
Author(s):  
Valeria Ettorre ◽  
Patrizia De Marco ◽  
Susi Zara ◽  
Vittoria Perrotti ◽  
Antonio Scarano ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
In Vivo Characterization

scholarly journals Real-time observation of tetrapyrrole binding to an engineered bacterial phytochrome

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yusaku Hontani ◽  
Mikhail Baloban ◽  
Francisco Velazquez Escobar ◽  
Swetta A. Jansen ◽  
Daria M. Shcherbakova ◽  
...  
Keyword(s):  
Real Time ◽  
Rational Design ◽  
Near Infrared ◽  
Fluorescent Proteins ◽  
Covalent Bond ◽  
Binding Pocket ◽  
Tissue Imaging ◽  
Covalent Attachment ◽  
Time Resolved

AbstractNear-infrared fluorescent proteins (NIR FPs) engineered from bacterial phytochromes are widely used for structural and functional deep-tissue imaging in vivo. To fluoresce, NIR FPs covalently bind a chromophore, such as biliverdin IXa tetrapyrrole. The efficiency of biliverdin binding directly affects the fluorescence properties, rendering understanding of its molecular mechanism of major importance. miRFP proteins constitute a family of bright monomeric NIR FPs that comprise a Per-ARNT-Sim (PAS) and cGMP-specific phosphodiesterases - Adenylyl cyclases - FhlA (GAF) domain. Here, we structurally analyze biliverdin binding to miRFPs in real time using time-resolved stimulated Raman spectroscopy and quantum mechanics/molecular mechanics (QM/MM) calculations. Biliverdin undergoes isomerization, localization to its binding pocket, and pyrrolenine nitrogen protonation in <1 min, followed by hydrogen bond rearrangement in ~2 min. The covalent attachment to a cysteine in the GAF domain was detected in 4.3 min and 19 min in miRFP670 and its C20A mutant, respectively. In miRFP670, a second C–S covalent bond formation to a cysteine in the PAS domain occurred in 14 min, providing a rigid tetrapyrrole structure with high brightness. Our findings provide insights for the rational design of NIR FPs and a novel method to assess cofactor binding to light-sensitive proteins.

scholarly journals Biomimetic reduced graphene oxide coated collagen scaffold for in situ bone regeneration

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sajad Bahrami ◽  
Nafiseh Baheiraei ◽  
Mostafa Shahrezaee
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Cranial Bone ◽  
Drying Methods ◽  
Porous Scaffolds ◽  
Alizarin Red ◽  
Reduced Graphene ◽  
Coated Collagen

AbstractA variety of bone-related diseases and injures and limitations of traditional regeneration methods require new tissue substitutes. Tissue engineering and regeneration combined with nanomedicine can provide different natural or synthetic and combined scaffolds with bone mimicking properties for implantation in the injured area. In this study, we synthesized collagen (Col) and reduced graphene oxide coated collagen (Col-rGO) scaffolds, and we evaluated their in vitro and in vivo effects on bone tissue repair. Col and Col-rGO scaffolds were synthesized by chemical crosslinking and freeze-drying methods. The surface topography, and the mechanical and chemical properties of scaffolds were characterized, showing three-dimensional (3D) porous scaffolds and successful coating of rGO on Col. The rGO coating enhanced the mechanical strength of Col-rGO scaffolds to a greater extent than Col scaffolds by 2.8 times. Furthermore, Col-rGO scaffolds confirmed that graphene addition induced no cytotoxic effects and enhanced the viability and proliferation of human bone marrow-derived mesenchymal stem cells (hBMSCs) with 3D adherence and expansion. Finally, scaffold implantation into rabbit cranial bone defects for 12 weeks showed increased bone formation, confirmed by Hematoxylin–Eosin (H&E) and alizarin red staining. Overall, the study showed that rGO coating improves Col scaffold properties and could be a promising implant for bone injuries.

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