Sharif Digital Repository

A magneto-photothermal therapy for cancer (in vitro photothermal therapy of prostate cancer cells and in vivo photothermal therapy of human glioblastoma tumors in the presence of an external magnetic field) was developed using superparamagnetic zinc ferrite spinel (ZnFe2O4)-reduced graphene oxide (rGO) nanostructures (with various graphene contents). In vitro application of a low concentration (10 μg mL-1) of the ZnFe 2O4-rGO (20 wt%) nanostructures under a short time period (∼1 min) of near-infrared (NIR) irradiation (with a laser power of 7.5 W cm-2) resulted in an excellent destruction of the prostate cancer cells, in the presence of a magnetic field (∼1 Tesla) used for localizing the... 

Superparamagnetic zinc ferrite spinel-graphene nanostructures were synthesized as potential therapeutic agents in the magnetic targeted photothermal therapy of cancer and/or drug delivery. The global temperature of the solution and the local temperature at the nanoparticle (NP) surface determine the protein corona composition/content, which in turn affects the biological effects of NPs and the corresponding physiological responses. Therefore, it is rational to hypothesize that spinel-graphene nanostructures may have distinct protein corona compositions and contents, and therapeutic and toxic effects under laser irradiation. To assess this hypothesis, the effects of laser irradiation on the... 

Reduced graphene oxide nanomesh (rGONM), as one of the recent structures of graphene with a surprisingly strong near-infrared (NIR) absorption, is used for achieving ultraefficient photothermal therapy. First, by using TiO2 nanoparticles, graphene oxide nanoplatelets (GONPs) are transformed into GONMs through photocatalytic degradation. Then rGONMs functionalized by polyethylene glycol (PEG), arginine-glycine-aspartic acid (RGD)-based peptide, and cyanine 7 (Cy7) are utilized for in vivo tumor targeting and fluorescence imaging of human glioblastoma U87MG tumors having ανβ3 integrin receptors, in mouse models. The rGONM-PEG suspension (1 μg mL -1) exhibits about 4.2- and 22.4-fold higher NIR... 

Graphene, a two-dimensional (2D) sheet of sp2-hybridized carbon atoms packed into a honeycomb lattice, has led to an explosion of interest in the field of materials science, physics, chemistry, and biotechnology since the few-layers graphene (FLG) flakes were isolated from graphite in 2004. For an extended search, derivatives of nanomedicine such as biosensing, biomedical, antibacterial, diagnosis, cancer and photothermal therapy, drug delivery, stem cell, tissue engineering, imaging, protein interaction, DNA, RNA, toxicity, and so on were also added. Since carbon nanotubes are normally described as rolled-up cylinders of graphene sheets and the controllable synthesis of nanotubes is well... 

Green tea-reduced graphene oxide (GT-rGO) sheets have been exploited for high efficiency near infrared (NIR) photothermal therapy of HT29 and SW48 colon cancer cells. The biocompatibility of GT-rGO sheets was investigated by means of MTT assays. The polyphenol constituents of GT-rGO act as effective targeting ligands for the attachment of rGO to the surface of cancer cells, as confirmed by the cell granularity test in flow cytometry assays and also by scanning electron microscopy. The photo-thermal destruction of higher metastatic cancer cells (SW48) is found to be more than 20% higher than that of the lower metastatic one (HT29). The photo-destruction efficiency factor of the GT-rGO is... 

Reduced graphene oxide nanoribbons functionalized by amphiphilic polyethylene glycol (rGONR-PEG) were applied to attach arginine-glycine-aspartic acid (RGD)-based peptide and cyanine dye 3 (cy3) for targeting ανβ3 integrin receptors on human glioblastoma cell line U87MG and its selective fluorescence imaging, respectively. The rGONR-PEG suspension with a concentration of 100 μg mL -1 showed ∼14 and 2.4-fold higher near infrared (NIR) absorption at 808 nm than GONR (with dimensions of ∼80 nm × 1 μm) and rGO-PEG sheets (with lateral dimensions of ∼2 μm), respectively. The rGONR-PEG-cy3-RGD exhibited highly efficient NIR photothermal therapy performance (concentrations ≥1.0 μg mL-1 resulted in... 

We study stationary entanglement properties of an optomechanical system containing an atomic ensemble. We focus onto the case of the movable mirror strongly coupled to the cavity field through both radiation pressure and photothermal force. Exploiting a quantum Langevin equation approach we investigate the bipartite entanglement properties of various bipartite subsystems as well as stationary tripartite entanglement of the system. We particularly study robustness of the atom-mirror entanglement against temperature. We show that, even though the photothermal force is a dissipative force, it can significantly improve the cavity mediated atom-mirror entanglement  

A single-step green method for effective reduction and functionalization of graphene oxide (GO) by glucose was developed. Then, efficacy of the glucose-reduced GO sheets in photothermal therapy of LNCaP prostate cancer cells was investigated in vitro. The GO suspension reduced and functionalized by glucose in the presence of Fe catalyst showed a biocompatible property with an excellent near-infrared (NIR) photothermal therapy efficiency better than hydrazine-reduced GO, single-wall and multi-wall carbon nanotube suspensions which even showed some levels of toxicities. For complete destruction of the cancer cells at some time intervals of NIR irradiation (e.g., 0.5 and 12 min with a power... 

Cooling and entanglement in optomechanical systems coupled through radiation pressure and photothermal force are studied. To develop the photothermal model, we derive an expression for deformation constant of the force. By exploiting linearized quantum Langevin equations, we investigate the dynamics of such systems. According to our analysis, in addition to separate action of radiation pressure and photothermal force, their cross-correlation effect plays an important role in the dynamics of the system. We also achieve an exact relation for the phonon number of the mechanical resonator in such systems, and then we derive an analytical expression for it at the weak-coupling limit. At the... 

Bioactivity of Escherichia coli bacteria (as a simple model for microorganisms) and interaction of them with the environment were controlled by their capturing within aggregated graphene nanosheets. The oxygen-containing functional groups of chemically exfoliated single-layer graphene oxide nanosheets were reduced by melatonin as a biocompatible antioxidant. While each one of the graphene (oxide) suspension and melatonin solution did not separately show any considerable inactivation effects on the bacteria, aggregation of the sheets in the melatonin-bacterial suspension resulted in trapping the bacteria within the aggregated sheets, i.e., a kind of inactivation. The bacteria trapped within... 

Nanotechnology has begun to play a remarkable role in various fields of science and technology. In biomedical applications, nanoparticles have opened new horizons, especially for biosensing, targeted delivery of therapeutics, and so forth. Among drug delivery systems (DDSs), smart nanocarriers that respond to specific stimuli in their environment represent a growing field. Nanoplatforms that can be activated by an external application of light can be used for a wide variety of photoactivated therapies, especially light-triggered DDSs, relying on photoisomerization, photo-cross-linking/un-cross-linking, photoreduction, and so forth. In addition, light activation has potential in photodynamic... 

New dual light/temperature-responsive nanocarriers were synthesized using bimetallic plasmonic Au-Ag and Ag-Au nanoparticles (NPs) as cores of vehicles which subsequently functionalized with an upper critical solubility temperature–based poly acrylamide-co-acrylonitrile using reversible addition-fragmentation chain transfer for spatiotemporally controlled chemo-photothermal synergistic cancer therapy. The bimetallic cores were assigned to sense wavelengths close to the localized surface plasmon resonance of monometallic NP shell to produce heat which not only can increase the surrounding temperature over the upper critical solubility temperature of polymer to open its valves and promote drug... 

Recent insights into the nanomedicine have revealed that nanoplatforms enhance the efficacy of carrier in therapeutic applications. Here, multifunctional nanoplatforms were utilized in miRNA-101 delivery and NIR thermal therapy to induce apoptosis in breast cancer cells. Au nanorods (NRs) or nanospheres (NSs) covered with graphene oxide (GO) were prepared and functionalized with polyethylene glycol as a stabilizer and poly-L-arginine (P-L-Arg) as a targeting agent. In nanoplatforms, coupling Au@GO prepared stable structures with higher NIR reactivity. P-L-Arg substantially enhanced the cellular uptake and gene retardation of stuffs coated by them. However, rod-shape nanoplatforms indicated... 

According to the latest report from the World Health Organization, an estimated 265,000 deaths still occur every year as a direct result of burn injuries. A widespread range of these deaths induced by burn wound happens in low- and middle-income countries, where survivors face a lifetime of morbidity. Most of the deaths occur due to infections when a high percentage of the external regions of the body area is affected. Microbial nutrient availability, skin barrier disruption, and vascular supply destruction in burn injuries as well as systemic immunosuppression are important parameters that cause burns to be susceptible to infections. Topical antimicrobials and dressings are generally... 

Introduction: MicroRNA-101 (miR-101) is an intense cancer suppressor with special algorithm to target a wide range of pathways and genes which indicates the ability to regulate apoptosis, cellular stress, metastasis, autophagy, and tumor growth. Silencing of some genes such as Stathmin1 with miR-101 can be interpreted as apoptotic accelerator and autophagy suppressor. It is hypothesized that hybrid microRNA (miRNA) delivery structures based on cationized graphene oxide (GO) could take superiority of targeting and photothermal therapy to suppress the cancer cells  

During the last few decades, nanotechnology has established many essential applications in the biomedical field and in particular for cancer therapy. Not only can nanodelivery systems address the shortcomings of conventional chemotherapy such as limited stability, non-specific biodistribution and targeting, poor water solubility, low therapeutic indices, and severe toxic side effects, but some of them can also provide simultaneous combination of therapies and diagnostics. Among the various therapies, the combination of chemo- and photothermal therapy (CT-PTT) has demonstrated synergistic therapeutic efficacies with minimal side effects in several preclinical studies. In this regard,... 

We present near-field photothermal heating capability of an aperture SNOM probe by exploiting a bowtie nanostructure on top of the probe aperture, which operates as a nanosource of heat to activate underlying nanoparticle. Heat generation density calculated for the bowtie nanostructure at its absorption resonance wavelength of 694 nm verifies efficient concentration of heating power at the bowtie tips, due to optical near-field effects. Total absorbed power for the nanodisk beneath the probe has the same resonance wavelength at 694 nm, which confirms that the temperature increase produced at the underneath nanoparticle is due to utilizing the bowtie nanostructure on top of the SNOM probe as...