Application of nanoparticles and nanomaterials in thermal ablation therapy of cancer

Cancer is one of the major health issues with increasing incidence worldwide. In spite of the existing conventional cancer treatment techniques, the cases of cancer diagnosis and death rates are rising year by year. Thus, new approaches are required to advance the traditional ways of cancer therapy. Currently, nanomedicine, employing nanoparticles and nanocomposites, offers great promise and new opportunities to increase the efficacy of cancer treatment in combination with thermal therapy. Nanomaterials can generate and specifically enhance the heating capacity at the tumor region due to optical and magnetic properties. The mentioned unique properties of nanomaterials allow inducing the heat and destroying the cancerous cells. This paper provides an overview of the utilization of nanoparticles and nanomaterials such as magnetic iron oxide nanoparticles, nanorods, nanoshells, nanocomposites, carbon nanotubes, and other nanoparticles in the thermal ablation of tumors, demonstrating their advantages over the conventional heating methods

New Technology and Techniques for Needle-Based Magnetic Resonance Image-Guided Prostate Focal Therapy

The most common diagnosis of prostate cancer is that of localized disease, and unfortunately the optimal type of treatment for these men is not yet certain. Magnetic resonance image (MRI)-guided focal laser ablation (FLA) therapy is a promising potential treatment option for select men with localized prostate cancer, and may result in fewer side effects than whole-gland therapies, while still achieving oncologic control. The objective of this thesis was to develop methods of accurately guiding needles to the prostate within the bore of a clinical MRI scanner for MRI-guided FLA therapy. To achieve this goal, a mechatronic needle guidance system was developed. The system enables precise targeting of prostate tumours through angulated trajectories and insertion of needles with the patient in the bore of a clinical MRI scanner. After confirming sufficient accuracy in phantoms, and good MRI-compatibility, the system was used to guide needles for MRI-guided FLA therapy in eight patients. Results from this case series demonstrated an improvement in needle guidance time and ease of needle delivery compared to conventional approaches. Methods of more reliable treatment planning were sought, leading to the development of a systematic treatment planning method, and Monte Carlo simulations of needle placement uncertainty. The result was an estimate of the maximum size of focal target that can be confidently ablated using the mechatronic needle guidance system, leading to better guidelines for patient eligibility. These results also quantified the benefit that could be gained with improved techniques for needle guidance

Laser-Spark Multicharged Ion Implantation System ‒ Application in Ion Implantation and Neural Deposition of Carbon in Nickel (111)

Carbon ions generated by ablation of a carbon target using an Nd:YAG laser pulse (wavelength λ = 1064 nm, pulse width τ = 7 ns, and laser fluence of 10-110 J/cm2) are characterized. Time-of-flight analyzer, a three-mesh retarding field analyzer, and an electrostatic ion energy analyzer are used to study the charge and energy of carbon ions generated by laser ablation. The dependencies of the ion signal on the laser fluence, laser focal point position relative to target surface, and the acceleration voltage are described. Up to C4+ are observed. When no acceleration voltage is applied between the carbon target and a grounded mesh in front of the target, ion energies up to ~400 eV/charge are observed. The time-of-flight signal is analyzed for different retarding field voltages in order to obtain the ion kinetic energy distribution. The ablation and Coulomb energies developed in the laser plasma are obtained from deconvolution of the ion time-of-flight signal. Deconvolution of the time-of-flight ion signal to resolve the contribution of each ion charge is accomplished using data from a retarding field analysis combined with the time-of-flight signal. The ion energy and charge state increase with the laser fluence. The position of the laser focal spot affects the ion generation, with focusing ~1.9 mm in front of the target surface yielding maximum ions. When an external electric field is applied in an ion drift region between the target and a grounded mesh parallel to the target, fast ions are extracted and separated, in time, due to increased acceleration with charge state. However, the ion energy accelerated by the externally applied electric field is less than the potential drop between the target and mesh due to plasma shielding. By coupling a spark discharge into a laser-generated carbon plasma, fully-stripped carbon ions with a relatively low laser pulse energy are observed. When spark-discharge energy of ~750 mJ is coupled to the carbon plasma generated by ~50 mJ laser pulse (wavelength 1064 nm, pulse width 8 ns, intensity 5 × 109 W/cm2), enhancement in the total ion charge by a factor of ~6 is observed, along with the increase of maximum charge state from C4+ to C6+. Spark coupling to the laser plasma significantly reduces the laser pulse energy required to generate highly-charged ions. Compared to the laser carbon plasma alone, the spark discharge increases the intensity of the spectral emission of carbon lines, the electron density ne, and the electron temperature Te. The effective ion plasma temperature associated with translational motion along the plume axis Tieff is calculated from the ion time-of-flight signal. Carbon laser plasma generated by an Nd:YAG laser (wavelength 1064 nm, pulse width 7 ns, fluence 4-52 J/cm2) is studied by optical emission spectroscopy and ion time-of-flight. Up to C4+ ions are detected with the ion flux strongly dependent on the laser fluence. The increase in ion charge with the laser fluence is accompanied by observation of multicharged ion lines in the optical spectra. The time-integrated electron temperature Te is calculated from the Boltzmann plot using the C II lines at 392.0, 426.7, and 588.9 nm. Te is found to increase from ~0.83 eV for a laser fluence of 22 J/cm2 to ~0.90 eV for 40 J/cm2. The electron density ne is obtained from the Stark broadened profiles of the C II line at 392 nm and is found to increase from ~2.1x1017 cm-3 for 4 J/ cm2 to ~3.5 x 1017 cm-3 for 40 J/cm2. Applying an external electric field parallel to the expanding plume shows no effect on the line emission intensities. Deconvolution of ion time-of-flight signal with a shifted Maxwell-Boltzmann distribution for each charge state results in an ion temperature Ti ~4.7 and ~6.0 eV for 20 and 36 J/cm2, respectively. Carbon ion emission from femtosecond laser ablation of a glassy carbon target is studied. A Ti:sapphire laser (pulse duration τ ~150 fs, wavelength λ = 800 nm, laser fluence F ≤ 6.4 J/cm2) is used to ablate the carbon target while ion emission is detected by a time-of-flight detector equipped with a three-grid retarding field analyzer. A strong effect of the laser pulse fluence on the yield of carbon ions is observed. Up to C6+ ions are detected. The carbon time-of-flight ion signal is fit to a shifted Maxwell-Boltzmann distribution and used to extrapolate the effective plasma ion temperature Tieff = 6.9 eV. Applying an external electric field along the plasma expansion direction increased ion extraction, possibly due to the retrograde motion of the plasma-vacuum edge. The laser ion source is utilized for carbon ion implantation of Ni(111), aiming for graphene synthesis. Ni(111) thin films are prepared with magnetron sputter coater on mica substrates at 500 °C with 400 nm thickness. Ni(111) thin films are analyzed with XRD and showed that the surface mostly contains single crystal Ni(111). Carbon at +5, -5, -10, and -15 keV of Ni (111) biasing with a series of dosages were implanted into Ni(111) films at room temperature. Carbon nanostructures such as amorphous carbon and diamond-like carbon were synthesized on Ni(111) substrates by the laser generated carbon ion implantation

Plasma Nanoscience: from Nano-Solids in Plasmas to Nano-Plasmas in Solids

The unique plasma-specific features and physical phenomena in the organization of nanoscale solid-state systems in a broad range of elemental composition, structure, and dimensionality are critically reviewed. These effects lead to the possibility to localize and control energy and matter at nanoscales and to produce self-organized nano-solids with highly unusual and superior properties. A unifying conceptual framework based on the control of production, transport, and self-organization of precursor species is introduced and a variety of plasma-specific non-equilibrium and kinetics-driven phenomena across the many temporal and spatial scales is explained. When the plasma is localized to micrometer and nanometer dimensions, new emergent phenomena arise. The examples range from semiconducting quantum dots and nanowires, chirality control of single-walled carbon nanotubes, ultra-fine manipulation of graphenes, nano-diamond, and organic matter, to nano-plasma effects and nano-plasmas of different states of matter.Comment: This is an essential interdisciplinary reference which can be used by both advanced and early career researchers as well as in undergraduate teaching and postgraduate research trainin

Carbon nanotubes in nanomedicine

The development of nanomedicine is based primarily on the development of smart and multifunctional nanomaterials that can serve under the different clusters including drug delivery systems, diagnostics, and regenerative medicine. Recently, carbon nanotubes (CNTs) have received enormous attention due to their extraordinary properties. CNTs have a wide range of applications and are used in a variety of products thus exposure to CNTs has become unavoidable, which may prompt an inflammatory response. The present Thesis is focused on studying CNTs especially addressing the key challenges highlighted by the Food and Drug Administration and the Alliance for Nano-Health, including imaging, biodistribution, interaction with biological environment, and predictive modeling. For imaging in order to evaluate biodistribution we were able, for the first time, to use thermostable Luciferase from Luciola cruciate (LcL) as a qualitative imaging modality. LcL offers an alternative approach for following the biodistribution of CNTs over time. The biodistribution profile of CNTs was found to be similar to the majority of nanoparticles, falling in the same size criteria, and predominantly accumulate in the liver. This raised the question whether CNTs could interfere with the liver functionality explicitly the metabolizing activity of drugs and other xenobiotics by phase I metabolizing enzymes CYP450. We therefore studied the ability of single wall carbon nanotubes (oxSWNTs) on inhibiting enzymatic capacity of CYP3A4. We found that oxSWNTs inhibit mediated conversion of testosterone (as a model compound), to its major metabolite 6β-hydroxy testosterone in a dose dependent manner. When oxSWNTs is pre-coated with bovine serum albumin, the enzymatic activity of CYP3A4 was restored. Also, the covalent functionalization of oxSWNTs with polyethylene glycol (PEG) has shown to have no influence on the enzymatic activity of CYP3A4. Further understanding of the molecular interactions was obtained by computational modeling and simulations (MD). MD simulations revealed that the inhibition of CYP3A4 catalytic activity is mainly due to blocking of the exit channel for substrate/products through a complex binding mechanism. CYP3A4 is a well-recognized isozyme accountable for the metabolization of various endogenous and exogenous xenobiotics by means of the monooxygenase cycle. In the Thesis, we also studied the degradation of pristine and oxidized SWNTs (p-SWNTs, oxSWNTs) by CYP3A4, by Raman spectroscopy. We found that both p-SWNTs and oxSWNTs were degraded as evidenced by the increase of D-band, which corresponds to the increase of the structural defects. Surprisingly, CYP3A4 bactosomes were more proficient in degrading p-SWNTs more than oxSWNTs under similar incubation conditions. MD simulations suggested that CYP3A4 has a higher affinity for p-SWNTs (minimal MolDock Score of −186.34 kcal/mol) compared to oxSWNTs which bind in a weaker manner (MolDock Score = −111.47 kcal/mol). Pulmonary accumulation of CNTs has shown to be critical. We therefore studied the biodegradation of oxSWNTs by Lactoperoxidase (LPO), a secreted peroxidase enzyme present in the mucus of the airways. We also investigated whether pulmonary surfactants can play a role in the biodegradation of oxSWNTs. Biodegradation was monitored using Raman spectroscopy, scanning electron microscopy, and UV–Vis–NIR spectroscopy. The biodegradation of oxSWNTs was not impeded by the formation of protein corona formed in the presence of lung surfactant (Curosurf®). Moreover, cell-free digestion of oxSWNTs was observed ex vivo in murine bronchoalveolar lavage fluid in the presence of peroxidase cofactors. Since CNTs is studied as a theranostic agent, we therefore studied the biodegradation of PEGylated oxSWNTs. PEG is acknowledged as the gold standard for extending blood circulation times for many biological molecules. OxSWNTs functionalized with PEG of different molecular weight (MW) were incubated with myeloperoxidase (MPO). Biodegradation was noted only for oxSWNTs chemically functionalized with PEG. There was no sign of degradation of oxSWNTs with physically adsorbed PEG, nor for p-SWNTs. The extent of oxSWNT biodegradation by MPO was inversely proportional to the molecular weight of the PEG chains. Ex vivo biodegradation using isolated primary human neutrophils revealed that both chemically and physically PEGylated oxSWNTs undergo biodegradation independently of the PEG chain MW. These ex vivo findings suggest that, in a cell system, a combined process of stripping and biodegradation of PEGylated oxSWNTs might occur

Applications of plasma-liquid systems : a review

Plasma-liquid systems have attracted increasing attention in recent years, owing to their high potential in material processing and nanoscience, environmental remediation, sterilization, biomedicine, and food applications. Due to the multidisciplinary character of this scientific field and due to its broad range of established and promising applications, an updated overview is required, addressing the various applications of plasma-liquid systems till now. In the present review, after a brief historical introduction on this important research field, the authors aimed to bring together a wide range of applications of plasma-liquid systems, including nanomaterial processing, water analytical chemistry, water purification, plasma sterilization, plasma medicine, food preservation and agricultural processing, power transformers for high voltage switching, and polymer solution treatment. Although the general understanding of plasma-liquid interactions and their applications has grown significantly in recent decades, it is aimed here to give an updated overview on the possible applications of plasma-liquid systems. This review can be used as a guide for researchers from different fields to gain insight in the history and state-of-the-art of plasma-liquid interactions and to obtain an overview on the acquired knowledge in this field up to now

Materials Chemistry of Fullerenes, Graphenes, and Carbon Nanotubes

This Special Issue is intended as a platform for interactive material science articles with an emphasis on the preparation, functionalization chemistry, and characterization of nanocarbon compounds, as well as all aspects of physical properties of functionalized, conjugated, or hybrid nanocarbon materials, and their associated applications. Some recent advances in the field are here collected, providing new ideas for discussion of researchers working in this multidisciplinary scenario

Anisotropic Hexagonal Boron Nitride Nanomaterials - Synthesis and Applications

Boron nitride (BN) is a synthetic binary compound located between III and V group elements in the Periodic Table. However, its properties, in terms of polymorphism and mechanical characteristics, are rather close to those of carbon compared with other III-V compounds, such as gallium nitride. BN crystallizes into a layered or a tetrahedrally linked structure, like those of graphite and diamond, respectively, depending on the conditions of its preparation, especially the pressure applied. Such correspondence between BN and carbon readily can be understood from their isoelectronic structures [1, 2]. On the other hand, in contrast to graphite, layered BN is transparent and is an insulator. This material has attracted great interest because, similar to carbon, it exists in various polymorphic forms exhibiting very different properties; however, these forms do not correspond strictly to those of carbon. Crystallographically, BN is classified into four polymorphic forms: Hexagonal BN (h-BN) (Figure 1(b)); rhombohedral BN (r-BN); cubic BN (c-BN); and wurtzite BN (w-BN). BN does not occur in nature. In 1842, Balmain [3] obtained BN as a reaction product between molten boric oxide and potassium cyanide under atmospheric pressure. Thereafter, many methods for its synthesis were reported. h-BN and r-BN are formed under ambient pressure. c-BN is synthesized from h-BN under high pressure at high temperature while w-BN is prepared from h-BN under high pressure at room temperature [1]. Each BN layer consists of stacks of hexagonal plate-like units of boron and nitrogen atoms linked by SP{sup 2} hybridized orbits and held together mainly by Van der Waals force (Fig 1(b)). The hexagonal polymorph has two-layered repeating units: AA'AA'... that differ from those in graphite: ABAB... (Figure 1(a)). Within the layers of h-BN there is coincidence between the same phases of the hexagons, although the boron atoms and nitrogen atoms are alternatively located along the c-axis. The rhombohedral system consists of three-layered units: ABCABC..., whose honeycomb layers are arranged in a shifted phase, like as those of graphite. Reflecting its weak interlayer bond, the h-BN can be cleaved easily along its layers, and hence, is widely used as a lubricant material. The material is stable up to a high temperature of 2300 C before decomposition sets in [2] does not fuse a nitrogen atmosphere of 1 atm, and thus, is applicable as a refractory material. Besides having such properties, similar to those of graphite, the material is transparent, and acts as a good electric insulator, especially at high temperatures (10{sup 6} {Omega}m at 1000 C) [1]. c-BN and w-BN are tetrahedrally linked BN. The former has a cubic sphalerite-type structure, and the latter has a hexagonal wurtzite-type structure. c-BN is the second hardest known material (the hardest is diamond), the so-called white diamond. It is used mainly for grinding and cutting industrial ferrous materials because it does not react with molten iron, nickel, and related alloys at high temperatures whereas diamond does [1]. It displays the second highest thermal conductivity (6-9 W/cm.deg) after diamond. This chapter focuses principally upon information about h-BN nanomaterials, mainly BN nanotubes (BNNTs), porous BN, mono- and few-layer-BN sheets. There are good reviews book chapters about c-BN in [1, 4-6]