scholarly journals Thermal-Recoverable Tough Hydrogels Enhanced by Porphyrin Decorated Graphene Oxide

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1487 ◽  
Author(s):  
Wang ◽  
Wei ◽  
Su ◽  
Qiu ◽  
Hu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Graphene Oxide ◽  
Laser Irradiation ◽  
Near Infrared ◽  
Mechanical Performance ◽  
The Body ◽  
Compressive Property ◽  
Photothermal Method ◽  
Nir Laser

Artificial tissue materials usually suffer properties and structure loss over time. As a usual strategy, a new substitution is required to replace the worn one to maintain the functions. Although several approaches have been developed to restore the mechanical properties of hydrogels, they require direct heating or touching, which cannot be processed within the body. In this manuscript, a photothermal method was developed to restore the mechanical properties of the tough hydrogels by using near infrared (NIR) laser irradiation. By adding the porphyrin decorated graphene oxide (PGO) as the nanoreinforcer and photothermal agent into carrageenan/polyacrylamide double network hydrogels (PDN), the compressive strength of the PDN was greatly improved by 104%. Under a short time of NIR laser irradiation, the PGO effectively converts light energy to thermal energy to heat the PDN hydrogels. The damaged carrageenan network was rebuilt, and a 90% compressive strength recovery was achieved. The PGO not only significantly improves the mechanical performance of PDN, but also restores the compressive property of PDN via a photothermal method. These tough hydrogels with superior photothermal recovery may work as promising substitutes for load-bearing tissues.

scholarly journals Bioactivity of PEGylated Graphene Oxide Nanoparticles Combined with Near-Infrared Laser Irradiation Studied in Colorectal Carcinoma Cells

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3061
Author(s):  
Natalia Krasteva ◽  
Dessislava Staneva ◽  
Bela Vasileva ◽  
George Miloshev ◽  
Milena Georgieva
Keyword(s):  
Colorectal Cancer ◽  
Graphene Oxide ◽  
Colorectal Carcinoma ◽  
Cancer Cells ◽  
Laser Irradiation ◽  
Molecular Mechanisms ◽  
Near Infrared ◽  
Carcinoma Cells ◽  
Infrared Light ◽  
Mitochondrial Activity

Central focus in modern anticancer nanosystems is given to certain types of nanomaterials such as graphene oxide (GO). Its functionalization with polyethylene glycol (PEG) demonstrates high delivery efficiency and controllable release of proteins, bioimaging agents, chemotherapeutics and anticancer drugs. GO–PEG has a good biological safety profile, exhibits high NIR absorbance and capacity in photothermal treatment. To investigate the bioactivity of PEGylated GO NPs in combination with NIR irradiation on colorectal cancer cells we conducted experiments that aim to reveal the molecular mechanisms of action of this nanocarrier, combined with near-infrared light (NIR) on the high invasive Colon26 and the low invasive HT29 colon cancer cell lines. During reaching cancer cells the phototoxicity of GO–PEG is modulated by NIR laser irradiation. We observed that PEGylation of GO nanoparticles has well-pronounced biocompatibility toward colorectal carcinoma cells, besides their different malignant potential and treatment times. This biocompatibility is potentiated when GO–PEG treatment is combined with NIR irradiation, especially for cells cultured and treated for 24 h. The tested bioactivity of GO–PEG in combination with NIR irradiation induced little to no damages in DNA and did not influence the mitochondrial activity. Our findings demonstrate the potential of GO–PEG-based photoactivity as a nanosystem for colorectal cancer treatment.

scholarly journals Influence of Glass Fibers on Mechanical Properties of Concrete with Recycled Coarse Aggregates

2019 ◽  
Vol 5 (5) ◽  
pp. 1007-1019 ◽  
Author(s):  
Babar Ali ◽  
Liaqat Ali Qureshi ◽  
Ali Raza ◽  
Muhammad Asad Nawaz ◽  
Safi Ur Rehman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Mechanical Performance ◽  
Volume Fraction ◽  
Glass Fibers ◽  
Construction Material ◽  
Concrete Compressive Strength ◽  
Coarse Aggregates ◽  
Highly Sensitive

Despite plain cement concrete presenting inferior performance in tension and adverse environmental impacts, it is the most widely used construction material in the world. Consumption of fibers and recycled coarse aggregates (RCA) can add ductility and sustainability to concrete. In this research, two mix series (100%NCA, and 100%RCA) were prepared using four different dosages of GF (0%GF, 0.25%GF, 0.5%GF, and 0.75%GF by volume fraction).  Mechanical properties namely compressive strength, splitting tensile strength, and flexural strength of each concrete mixture was evaluated at the age of 28 days. The results of testing indicated that the addition of GF was very useful in enhancing the split tensile and flexural strength of both RCA and NCA concrete. Compressive strength was not highly sensitive to the addition of GF. The loss in strength that occurred due to the incorporation of RCA was reduced to a large extent upon the inclusion of GF. GF caused significant improvements in the split tensile and flexural strength of RCA concrete. Optimum dosage of GF was determined to be 0.25% for NCA, and 0.5% for RCA concrete respectively, based on the results of combined mechanical performance (MP).

scholarly journals Plasmonic photothermal microneedle arrays and single needles for minimally-invasive deep in-skin hyperthermia

2020 ◽  
Vol 8 (25) ◽  
pp. 5425-5433 ◽  
Author(s):  
Álvaro Cárcamo-Martínez ◽  
Brónach Mallon ◽  
Juan Domínguez-Robles ◽  
A. Sara Cordeiro ◽  
Maurizio Celentano ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Laser Irradiation ◽  
Gold Nanorods ◽  
Near Infrared ◽  
Skin Model ◽  
Thickness Skin ◽  
Microneedle Arrays ◽  
First Time ◽  
Nir Laser ◽  
Deep Hyperthermia

We report, for the first time, crosslinked polymeric microneedle (MN) arrays and single needles (2 mm and 4.5 mm length) coated with gold nanorods (GnRs) to induce deep hyperthermia in a 3 mm-thickness skin model upon near infrared (NIR) laser irradiation.

Graphene oxide wrapped gold nanorods for enhanced photo-thermal stability

RSC Advances ◽  
2015 ◽  
Vol 5 (68) ◽  
pp. 54971-54977 ◽  
Author(s):  
Qingli Wei ◽  
Hong Ni ◽  
Xue Jin ◽  
Jing Yuan
Keyword(s):  
Thermal Stability ◽  
Graphene Oxide ◽  
Laser Irradiation ◽  
Gold Nanorods ◽  
Nir Laser

NanoGO wrapped Gold nanorods show enhanced photothermal stability under continuous NIR laser irradiation.

scholarly journals Mechanical Performance and Microscopic Mechanism of Coastal Cemented Soil Modified by Iron Tailings and Nano Silica

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1331
Author(s):  
Xinjiang Song ◽  
Haibo Xu ◽  
Deqin Zhou ◽  
Kai Yao ◽  
Feifei Tao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Mechanical Performance ◽  
Hydration Reaction ◽  
Unconfined Compression ◽  
Nano Silica ◽  
Microscopic Mechanism ◽  
Clay Particles ◽  
Soil Cement ◽  
Cement Soil

In order to explore the effect of composite materials on the mechanical properties of coastal cement soil, cement soil samples with different iron tailings and nano silica contents were prepared, and unconfined compression and scanning electron microscope tests were carried out. The results show that: (1) The compressive strength of cement soil containing a small amount of iron tailings is improved, and the optimum content of iron tailings is 20%. (2) Nano silica can significantly improve the mechanical properties of iron tailings and cement soil (TCS). When the content of nano silica is 0.5%, 1.5%, and 2.5%, the unconfined compressive strength of nano silica- and iron tailings-modified cement soil (STCS) is 24%, 137%, and 323% higher than TCS, respectively. (3) Nano silica can promote the hydration reaction of cement and promote the cement hydration products to adhere to clay particles to form a relatively stable structure. At the same time, nano silica can fill the pores in TCS and improve the compactness of STCS.

scholarly journals Near-Infrared Fluorescent Sorbitol Probe for Targeted Photothermal Cancer Therapy

Cancers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1286 ◽  
Author(s):  
Lee ◽  
Jung ◽  
Jo ◽  
Yang ◽  
Koh ◽  
...  
Keyword(s):  
Cancer Therapy ◽  
Laser Irradiation ◽  
Near Infrared ◽  
Photothermal Effect ◽  
Great Promise ◽  
Targeted Cancer Therapy ◽  
Potential Applications ◽  
Photothermal Property ◽  
Nir Laser

Abstract: Photothermal therapy (PTT) using a near-infrared (NIR) heptamethine cyanine fluorophore has emerged as an alternative strategy for targeted cancer therapy. NIR fluorophores showing a high molar extinction coefficient and low fluorescence quantum yield have considerable potential applications in photothermal cancer therapy. In this study, a bifunctional sorbitol–ZW800 conjugate was used as an advanced concept of photothermal therapeutic agents for in vivo cancer imaging and therapy owing to the high tumor targetability of the sorbitol moiety and excellent photothermal property of NIR heptamethine cyanine fluorophore. The sorbitol–ZW800 showed an excellent photothermal effect increased by 58.7 °C after NIR laser irradiation (1.1 W/cm2) for 5 min. The HT-29 tumors targeted by sorbitol–ZW800 showed a significant decrease in tumor volumes for 7 days after photothermal treatment. Therefore, combining the bifunctional sorbitol–ZW800 conjugate and NIR laser irradiation is an alternative way for targeted cancer therapy, and this approach holds great promise as a safe and highly efficient NIR photothermal agent for future clinical applications.

scholarly journals Effect of Graphene Oxide/Graphene Hybrid on Mechanical Properties of Cement Mortar and Mechanism Investigation

Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 113 ◽  
Author(s):  
Hongfang Sun ◽  
Li Ling ◽  
Zhili Ren ◽  
Shazim Ali Memon ◽  
Feng Xing
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Graphene Oxide ◽  
Flexural Strength ◽  
Pore Size Distribution ◽  
Cement Mortar ◽  
Underlying Mechanism ◽  
Mortar Specimen ◽  
Degree Of Hydration ◽  
Cement Mortars

This paper evaluated the effect of graphene oxide/graphene (GO/GR) hybrid on mechanical properties of cement mortar. The underlying mechanism was also investigated. In the GO/GR hybrid, GO was expected to act as a dispersant for GR while GR was used as reinforcement in mortar due to its excellent mechanical properties. For the mortar specimen, flexural and compressive strength were measured at varied GO to GR ratios of 1:0, 3:1, 1:1, 1:3, and 0:1 by keeping the total amount of GO and GR constant. The underlying mechanism was investigated through the dispersibility of GR, heat releasing characteristics during hydration, and porosity of mortar. The results showed that GO/GR hybrid significantly enhanced the flexural and compressive strength of cement mortars. The flexural strength reached maximum at GO:GR = 1:1, where the enhancement level was up to 23.04% (28 days) when compared to mortar prepared with only GO, and up to 15.63% (7 days) when compared to mortar prepared with only GR. In terms of compressive strength, the enhancement level for GO:GR = 3:1 was up to 21.10% (3 days) when compared with that of mortar incorporating GO only. The enhancement in compressive strength with mortar at GO:GR = 1:1 was up to 14.69% (7-day) when compared with mortar incorporating GR only. In addition to dispersibility, the compressive strength was also influenced by other factors, such as the degree of hydration, porosity, and pore size distribution of mortar, which made the mortars perform best at different ages.

Engineering nanoparticles to locally activate T cells in the tumor microenvironment

2019 ◽  
Vol 4 (37) ◽  
pp. eaau6584 ◽  
Author(s):  
Dangge Wang ◽  
Tingting Wang ◽  
Haijun Yu ◽  
Bing Feng ◽  
Lei Zhou ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Laser Irradiation ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Near Infrared ◽  
Checkpoint Inhibitors ◽  
Immunological Tolerance ◽  
Immune Checkpoint Blockade ◽  
Tumor Resistance ◽  
Nir Laser

Immunological tolerance of tumors is characterized by insufficient infiltration of cytotoxic T lymphocytes (CTLs) and immunosuppressive microenvironment of tumor. Tumor resistance to immune checkpoint inhibitors due to immunological tolerance is an ongoing challenge for current immune checkpoint blockade (ICB) therapy. Here, we report the development of tumor microenvironment–activatable anti-PDL1 antibody (αPDL1) nanoparticles for combination immunotherapy designed to overcome immunological tolerance of tumors. Combination of αPDL1 nanoparticle treatment with near-infrared (NIR) laser irradiation–triggered activation of photosensitizer indocyanine green induces the generation of reactive oxygen species, which promotes the intratumoral infiltration of CTLs and sensitizes the tumors to PDL1 blockade therapy. We showed that the combination of antibody nanoparticles and NIR laser irradiation effectively suppressed tumor growth and metastasis to the lung and lymph nodes in mouse models. The nanoplatform that uses the antibody nanoparticle alone both for immune stimulation and PDL1 inhibition could be readily adapted to other immune checkpoint inhibitors for improved ICB therapy.

Stimuli-responsive graphene oxide and methotrexate-loaded magnetic nanoparticles for breast cancer-targeted therapy

Nanomedicine ◽  
2021 ◽  
Vol 16 (24) ◽  
pp. 2155-2174
Author(s):  
Mitra Dolatkhah ◽  
Nastaran Hashemzadeh ◽  
Jaleh Barar ◽  
Khosro Adibkia ◽  
Ayuob Aghanejad ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Graphene Oxide ◽  
Near Infrared ◽  
Folate Receptor ◽  
Superparamagnetic Iron Oxide ◽  
Photothermal Effect ◽  
Breast Cancer Cell Lines ◽  
Stimuli Responsive ◽  
High Cytotoxicity ◽  
Nir Laser

Aim: Nanocomposites of graphene oxide (GO) loaded with PEGylated superparamagnetic iron oxide nanoparticles and grafted with methotrexate and stimuli-responsive linkers (GO-SPION-MTX) were developed for photothermal and chemotherapy of breast cancer. Methods: PEGylated SPIONs were synthesized and conjugated with chemotherapeutic targeting agent MTX, which were then loaded on GO to prepare GO-SPION-MTX nanocomposites. To evaluate the photothermal effect of the nanocomposites, they were examined in breast cancer cell lines with low doses of near-infrared (NIR) laser radiation with/without acetazolamide. Results: The GO-SPION-MTX nanocomposites were found to be internalized by the folate-receptor-positive cancer cells and induce high cytotoxicity on exposure to NIR laser rays. Conclusion: Our findings suggest that the GO-SPION-MTX nanocomposite can potentially be used as a multimodal nanomedicine/theranostic against breast cancer.

Photo-Thermal Conversion and Stability of Gold and Silver Nanostructures

2014 ◽  
Vol 906 ◽  
pp. 204-213 ◽  
Author(s):  
Yuan Ni ◽  
Cai Xia Kan ◽  
Bo Cong ◽  
Jin Sheng Liu ◽  
Hai Ying Xu
Keyword(s):  
Surface Plasmon Resonance ◽  
Laser Irradiation ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Near Infrared ◽  
Shape Change ◽  
Thermal Conversion ◽  
Silver Nanostructures ◽  
Au Nanorods ◽  
Nir Laser

Gold and silver nanostructures (such as Au nanorods and Ag nanoplates) exhibit strong and tunable surface plasmon resonance in the near-infrared region (NIR). Under a certain NIR laser irradiation, noble metal nanostructrues achieve a high photo-thermal effect, which would be useful in the therapy. In this work, Au nanorods with longitude surface plasmon resonance (SPRL) shifting in the region of 650 ~1100 nm were synthesized by a seed method. Ag nanoplates and nanocubes with SPR located in the region of 650~850 nm were produced by a hydrothermal method. Through adjusting laser power and irradiating time, the photo-thermal conversions of these nanostructures were studied under NIR laser irradiation. Under low power laser (808 nm, <1W) irradiation, the shape of the Au nanorods are stable and the temperature of colloid increase from room temperature to ~57°C. However, Au nanorods undergo deformation from rod to spherical particle under irradiation of high power (808 nm laser; 6W; 1064nm laser, 7W), resulting in the disappearance of SPRL. Morphology evolutions and photo-thermal conversion of Ag nanostructures were also studied. Ag nanostructures have a lower photo-thermal conversion compared with that of Au nanorods colloid. Snipping and dendrite can be observed for Ag nanoplates after irradiating, while Ag nanocubes have no obvious shape change.

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