Microwave Heating of Crystals with Gold Nanoparticles and Synovial Fluid under Synthetic Skin Patches

Microwave Hyperpolarization Effect─An Orthogonal Incoherent Microwave Field Heating Study

In our previous study, the incoherent combined microwave sources possess a higher water heating rate than a single microwave source. This novel discovery may blaze a new trail in the pursuit of energy conservation. In this paper, a particular orthogonal microwave field device was designed to quantitatively study the effect of incoherent combined microwave heating on 17 solvents. Experimental results indicate that the solvents irradiated with incoherent combined microwaves absorb more microwave energy and experience a faster temperature rise. The multiphysics simulations of water with different microwaves show that the higher heating rate is not caused by the improvement of heating uniformity. In this regard, molecular dynamics simulations of ethanol under the irradiation of incoherent microwave electric fields with perpendicular polarization directions were carried out. The molecular dynamics simulations demonstrate that the main reason for this effect is the higher collision frequency of molecules with incoherent microwave electric fields. This study demonstrates a novel effect of incoherent combined microwave heating and contributes to the development of efficient microwave heating for industrial applications.

The efficient thermal processing of cylindrical multiphase meat: a study on the selection of microwave heating strategy

The two-dimensional cylindrically shaped multiphase meat sample was modelled for microwave processing for two different interaction techniques i.e., lateral and radial during mono-mode operation of waveguide. The study was aimed to analyze the effect of volume fraction and sample size along with the duration of the procedure on the heat distribution corresponding to specified frequency and intensity of microwave. Procedure exhibiting higher heating rate and lower thermal non-homogeneity was set as the deciding factor for an optimal heating scheme. In order to achieve optimal processing at both 915 and 2450 MHz frequency, rotation of smaller samples and non-rotation of larger samples were recommended in most of the case studies; however, few exceptions were also observed and reported. In addition, reciprocity between volume fraction, intensity of the microwave radiation and procedure duration was also discussed. Overall, the present study would guide the studies on the microwave processing of two-dimensional multiphase meat.

Preparation of AuNPs/SF Nanofibers and Its Ability to Inhibit Tumor Growth in Breast Cancer-Bearing Animal Models

Silk fibroin was used as a stabilizer for gold nanoparticles, and a direct silk fibroin-gold nanoparticle composite system was prepared by a direct compounding method in this paper. The stability of Au NPs/SF in phosphate buffer solution with different pH and KCl concentration was studied. The Au NPs/SF system was characterized by UV-visible light spectrum, transmission electron microscope and infrared spectrum. The silk fibroin-gold nanoparticle composite system was prepared by in situ reduction of chloroauric acid with silk fibroin, according to the change of solution color and the change of ultraviolet absorption peak. The effects of exogenous factors on the stability of the silk fibroin-gold nanoparticle in situ composite system were initially discussed, and its inhibition in breast cancer-bearing animal models was studied. In vivo experiments show that in situ injection of Au NPs/SF nanofibers and treatment with light can effectively control tumor growth. Compared with monodisperse gold nanoparticles, silk fibroin-gold nanoparticles can kill tumor cells and inhibit tumor tissue growth more effectively.

Biofluidic material-based carriers: Potential systems for crossing cellular barriers

Biofluids act as a repository for disease biomarkers and are excellent diagnostic tools applied in establishing a disease profile based on clinical testing, evaluation and monitoring the progression of patients suffering from various conditions. Furthermore, biofluids and their derived components such proteins, pigments, enzymes, hormones and cells carry a potential in the development of therapeutic drug delivery systems or as cargo materials for targeting the drug to the site of action. The presence of biofluids with respect to their specific location reveals the information of disease progression and mechanism, delivery aspects such as routes of administration as well as pharmacological factors such as binding affinity, rate of kinetics, efficacy, bioavailability and patient compliance. This review focuses on the properties and functional benefits of some biofluids, namely blood, saliva, bile, urine, amniotic fluid, synovial fluid and cerebrospinal fluid. It also covers the therapeutic and targeting action of fluid-derived substances in various micro- or nano-systems like nanohybrids, nanoparticles, self-assembled micelles, microparticles, cell-based systems, etc. The formulation of such biologically-oriented systems demonstrate the advantages of natural origin, biocompatibility and biodegradability and offer new techniques for overcoming the challenges experienced in conventional therapies.

Remotely Activated Nanoparticles for Anticancer Therapy

Cancer has nowadays become one of the leading causes of death worldwide. Conventional anticancer approaches are associated with different limitations. Therefore, innovative methodologies are being investigated, and several researchers propose the use of remotely activated nanoparticles to trigger cancer cell death. The idea is to conjugate two different components, i.e., an external physical input and nanoparticles. Both are given in a harmless dose that once combined together act synergistically to therapeutically treat the cell or tissue of interest, thus also limiting the negative outcomes for the surrounding tissues. Tuning both the properties of the nanomaterial and the involved triggering stimulus, it is possible furthermore to achieve not only a therapeutic effect, but also a powerful platform for imaging at the same time, obtaining a nano-theranostic application. In the present review, we highlight the role of nanoparticles as therapeutic or theranostic tools, thus excluding the cases where a molecular drug is activated. We thus present many examples where the highly cytotoxic power only derives from the active interaction between different physical inputs and nanoparticles. We perform a special focus on mechanical waves responding nanoparticles, in which remotely activated nanoparticles directly become therapeutic agents without the need of the administration of chemotherapeutics or sonosensitizing drugs.

Metal-Assisted and Microwave-Accelerated Decrystallization of Pseudo-Tophus in Synthetic Human Joint Models

In this paper, we tested a hypothesis that the metal-assisted and microwave-accelerated decrystallization (MAMAD) technique, based on the combined use of low-power medical microwave heating (MWH) and gold nanoparticles (Au NPs), can be used to decrystallize laboratory-prepared monosodium urate monohydrate crystal aggregate (pseudo-tophus) placed in three-dimensional (3D) synthetic human joint models. To simulate a potential treatment of chronic tophaceous gout using the MAMAD technique, we used three different 3D synthetic human joint models and assessed the percent mass reduction (PMR, i.e., decrystallization) of pseudo-tophus and microwave-induced synthetic skin patch damage after MAMAD sessions (a MAMAD session = 120 s of MWH in the presence of Au NPs). Our three synthetic joint models are: Model 1: Application of seven MAMAD sessions in a closed synthetic joint with a pseudo-bursa containing a pseudo-tophus submerged in a solution of 20 nm Au NPs followed by dehydration of pseudo-tophus after each MAMAD session to assess PMR. Model 2: Application of seven MAMAD sessions in a closed or open synthetic joint with a pseudo-bursa containing a pseudo-tophus submerged in a solution of Au NPs followed by intermittent dehydration of pseudo-tophus after seven MAMAD sessions to assess PMR. Model 3: Application of 18 MAMAD sessions in a rotated closed synthetic joint (three sides are heated separately) with a pseudo-bursa containing a pseudo-tophus submerged in a solution of Au NPs followed by dehydration after every three MAMAD sessions to assess PMR. After a single MAMAD session, pseudo-tophus exposed to MWH and Au NPs had an average PMR of 8.30% (up to an overall PMR of 15%), and microwave-induced damage to the synthetic skin can be controlled by the use of a sacrificial skin sample and by adjusting the duration and the number of the MAMAD sessions. Computational electromagnetic simulations predict a 10% absorption of electric field by the pseudo-tophus placed in the synthetic joint models, which led us to conclude that a medical microwave source with higher power than 20 W can potentially be used with the MAMAD technique.