Smartphone-based iontophoresis transdermal drug delivery system for cancer treatment.

Cancer is a leading cause of the death worldwide. However, the conventional cancer therapy still suffers from several limitations, such as systemic side effects, poor efficacy, and patient compliance due to limited accessibility to the tumor site. To address these issues, the localized drug delivery system has emerged as a promising approach. In this study, we developed an iontophoresis-based transdermal drug delivery system (TDDS) controlled by a smartphone application for cancer treatment. Iontophoresis, a low-intensity electric current-based TDDS, enhances drug permeation across the skin to provide potential for localized drug delivery and minimize systemic side effects. The fundamental mechanism of our system was modeled using finite element analysis and its performance was corroborated through the flow-through skin permeation tests using a plastic-based microfluidic chip. The results of in vitro cell experiments and skin deposition tests successfully demonstrated that our smartphone-controlled iontophoresis system significantly enhanced the drug permeation for cancer treatment. Therefore, this hand-held smartphone-based iontophoresis TDDS could be a powerful tool for self-administrated anticancer drug delivery applications.

Conductive Silver/Carbon Fiber Films for Rapid Detection of Human Coronavirus.

Polymerase chain reaction has gained attention since the outbreak of novel coronavirus in 2019. Due to its high specificity and capability for early detection, it is considered a standard method for the diagnosis of infectious diseases. However, the conventional thermocyclers used for nucleic acid amplification are not suitable for point-of-care testing applications, as they require expensive instruments, high-power consumption, and a long turnaround time. To suppress the widespread of the pandemic, there is an urgent need for the development of a rapid, inexpensive, and portable thermal cycler. Therefore, in this paper, we present a conductive silver/carbon fiber film-based thermal cycler with low power consumption (<5 W), efficient heating (~4.5 °C/s), low cost (

Microfluidic electrode array chip for electrical stimulation-mediated axonal regeneration.

The precise manipulation of the neural stem cell (NSC)-derived neural differentiation is still challenging, and there is a technological barrier to regulate the axonal regeneration in a controlled manner. Here, we developed a microfluidic chip integrated with a microelectrode array as an axonal guidance platform. The microfluidic electrode array chip consisted of two compartments and a bridge microchannel that could isolate and guide the axons. We demonstrated that the NSCs were largely differentiated into neural cells as the electric field was applied to the microfluidic electrode array chip. We also confirmed the synergistic effects of the electrical stimulation (ES) and neurotrophic factor (NF) on axonal outgrowth. This microfluidic electrode array chip can serve as a central nervous system (CNS) model for axonal injury and regeneration. Therefore, it could be a potentially powerful tool for an in vitro model of the axonal regeneration.

Contributions of the microbiome to intestinal inflammation in a gut-on-a-chip.

The intestinal microbiome affects a number of biological functions of the organism. Although the animal model is a powerful tool to study the relationship between the host and microbe, a physiologically relevant in vitro human intestinal system has still unmet needs. Thus, the establishment of an in vitro living cell-based system of the intestine that can mimic the mechanical, structural, absorptive, transport and pathophysiological properties of the human intestinal environment along with its commensal bacterial strains can promote pharmaceutical development and potentially replace animal testing. In this paper, we present a microfluidic-based gut model which allows co-culture of human and microbial cells to mimic the gastrointestinal structure. The gut microenvironment is recreated by flowing fluid at a low rate (21 µL/h) over the microchannels. Under these conditions, we demonstrated the capability of gut-on-a-chip to recapitulate in vivo relevance epithelial cell differentiation including highly polarized epithelium, mucus secretion, and tight membrane integrity. Additionally, we observed that the co-culture of damaged epithelial layer with the probiotics resulted in a substantial responded recovery of barrier function without bacterial overgrowth in a gut-on-a-chip. Therefore, this gut-on-a-chip could promote explorations interaction with host between microbe and provide the insights into questions of fundamental research linking the intestinal microbiome to human health and disease.

Three-Dimensional Flexible All-Organic Conductors for Multifunctional Wearable Applications.

Wearable textile electrodes based on π-conjugated polymers are appealing alternatives to carbon fabrics, conductive yarns, or metal wires because of their design flexibility, low cost, flexibility, and high throughput. This provides the benefits of both electronics and textiles. Herein, a general and new method has been developed to produce tailorable, wearable energy devices that are based on three-dimensional (3D) poly(3,4-ethylenedioxythiophene) (PEDOT)-coated textile conductors. To obtain the desired electrode materials, both facile solution-dropping polymerization methods are used to fabricate a 3D flexible PEDOT conductor on a cotton textile (PEDOT/textile). PEDOT/textile shows a very low sheet resistance of 4.6-4.9 Ω·sq-1. Here, we employ the example of this 3D network-like structure and the excellent electrical conductivities under the large deformation of PEDOT/textiles to show that wearable and portable heaters have immense potential. A flexible textile heater with a large area (8 × 7.8 cm2) reached a saturation temperature of ∼83.9 °C when a bias of 7 V was applied for ∼70 s due to the good electrical conductivity of PEDOT. To demonstrate the performance of all-solid-state supercapacitors, nano-ascidian-like PEDOT (PEDOT-NA) arrays were prepared via a simple vapor-phase polymerization of 3,4-ethylenedioxythiophene on PEDOT/textile to increase both the surface area and the number of ion diffusion paths. The PEDOT-NA arrays on PEDOT/textile showed outstanding performance with an areal capacitance of 563.3 mF·cm-2 at 0.4 mA·cm-2 and extraordinary mechanical flexibility. The maximum volumetric power density and energy density of the nanostructured PEDOT on the textile were 1.75 W·cm-3 and 0.0812 Wh·cm-3, respectively. It is expected that the wearable nanostructured conducting polymers will have advantages when used as structures for smart textronics and energy conversion/storage.

Optimization of lactulose synthesis from whey lactose by immobilized ß-galactosidase and glucose isomerase.

In the present study, commercially available whey was used as a lactose source, and immobilized ß-galactosidase and glucose isomerase were used to synthesize lactulose from whey lactose in the absence of fructose. Optimal reaction conditions, such as lactose concentration, temperature, ionic strength of the buffer, and ratio of immobilized enzymes, were determined to improve lactulose synthesis using immobilized enzymes. Lactulose synthesis using immobilized enzymes improved markedly after optimizing the reaction conditions. When the lactulose synthesis was carried out at 53.5°C using 20% (w/v) whey lactose, 12U/ml of immobilized ß-galactosidase and 60U/ml of immobilized glucose isomerase in 100mM sodium phosphate buffer at pH 7.5, the lactulose concentration and specific productivity were 7.68g/l and 0.32mg/Uh, respectively. Additionally, when the immobilized enzymes were reused for lactulose synthesis, their catalytic activity was 57.1% after 7 repeated uses.

Batch and continuous synthesis of lactulose from whey lactose by immobilized ß-galactosidase.

In this study, lactulose synthesis from whey lactose was investigated in batch and continuous systems using immobilized ß-galactosidase. In the batch system, the optimal concentration of fructose for lactulose synthesis was 20%, and the effect of galactose, glucose and fructose on ß-galactosidase activity was determined for hydrolysis of whey lactose and the transgalactosylation reaction for lactulose synthesis. Galactose and fructose were competitive inhibitors, and glucose acted as a noncompetitive inhibitor. The inhibitory effects of galactose and glucose were stronger in the transgalactosylation reaction than they were in the hydrolysis reaction. In addition, when immobilized ß-galactosidase was reused for lactulose synthesis, its catalytic activity was retained to the extent of 52.9% after 10 reuses. Lactulose was synthesized continuously in a packed-bed reactor. We synthesized 19.1g/l lactulose during the continuous flow reaction at a flow rate of 0.5 ml/min.

Quantitative detection of glyphosate by simultaneous analysis of UV spectroscopy and fluorescence using DNA-labeled gold nanoparticles.

A sandwich-type immunosensor composed of antigen-double target/probe DNA-coated gold nanoparticles (NPs) was developed for the measurement of fluorescence intensity and quantitative analysis of single-stranded DNA based on the concentration of free glyphosate. The reaction between the antigen-double DNA-gold NPs and immobilized antibody on the substrate was carried out for 2 h. The results of the antigen-antibody reaction were measured on the basis of the fluorescence intensity obtained from comparison with the free antigens at concentrations of 0.01-100 µg mL(-1) for the detection of immobilized antigen-double DNA-gold NPs. For the quantitative analysis based on the concentration of glyphosate(0.01-100 µg mL(-1)), the immunosensor response also revealed the same detection range of glyphosate using DNA detection.