Improving quantitative control and homogeneous distribution of samples on paper-based analytical devices via drop-on-demand inkjet printing.

A standard desktop printer with multiple ink cartridges can accurately deposit a broad variety of biomaterials on microfluidic paper-based analytical devices (µPADs) which have been extensively applied to environmental monitoring and screening of food and beverage contamination. Finding ways to realize sample quantitative control by tuning the CMYK value, however, remains challenging. Herein, we studied the influence of the CMYK value on the ink volume jetted by ink cartridges. The regularity research on a single-color and two-colors was performed in two print mode-grayscale printing and color printing. The results demonstrated that the number of ink dots increased with the increase of the gray value and opacity value, which means that the amount of the bio-ink increases with the increase of the CMYK value. The 3,3',5,5'-tetramethylbenzidine-horseradish peroxidase-hydrogen peroxide, glucose oxidase-horseradish peroxidase and bull serum albumin-citrate buffer-tetrabromophenol blue systems were chosen as examples to prove the print regularity. Samples and assay reagents can be quantitatively deposited on a substrate by adjusting the CMYK value with as many as four ink cartridges. The present approach has been successfully applied to assay the targets in real serum samples, showing the potential application of the most common office piezoelectric printer in µPADs.

Higher Prevalence of Endometrial Polyps in Infertile Patients with Endometriosis.

AIM: To study whether infertile patients with endometriosis have a higher prevalence of endometrial polyps, and to clarify the characteristics of the pathology of combined polyps. METHODS: Infertile patients who had undergone both hysteroscopy and laparoscopy in Reproductive Hospital Affiliated with Shandong University from January 2014 to May 2017 were enrolled. Patients with and without endometriosis, diagnosed by laparoscopy, were staged and included in the study group and control group, respectively, and the prevalence of polyps was compared. The pathological types of endometrial polyps were analyzed. RESULTS: A total of 414 cases were enrolled in the study group and 3,048 cases in the control group; polyps were diagnosed, with endoscopy, in 1,107 patients. Endometrial polyps were detected by hysteroscopy in 47.83% of the endometriosis group and 29.82% of the control group. The prevalence of endometrial polyps was significantly higher in the endometriosis group than in the control group (p < 0.001) but not significantly different between stages of endometriosis (p = 0.580). The pathological diagnosis included 899 endometrial polyps and 208 polypoid hyperplasia; 66.5% of endometrial polyps were combined with simple hyperplasia. CONCLUSIONS: The infertile patients with endometriosis had a higher prevalence of endometrial polyps, and those polyps are often combined with simple hyperplasia.

A dual-readout sensing platform for the evaluation of cell viability integrating with optical and digital signals based on a closed bipolar electrode.

Cell viability is essential for predicting drug toxicity and assessing drug effects in drug screening. However, the over/underestimation of cell viability measured by traditional tetrazolium colorimetric assays is inevitable in cell-based experiments. Hydrogen peroxide (H2O2) secreted by living cells may provide more comprehensive information about the cell state. Hence, it is significant to develop a simple and rapid approach for evaluating cell viability by measuring the excreted H2O2. In this work, we developed a dual-readout sensing platform based on optical and digital signals by integrating a light emitting diode (LED) and a light dependent resistor (LDR) into a closed split bipolar electrode (BPE), denoted as BP-LED-E-LDR, for evaluating cell viability by measuring the H2O2 secreted from living cells in drug screening. Additionally, the customized three-dimensional (3D) printed components were designed to adjust the distance and angle between the LED and LDR, achieving stable, reliable and highly efficient signal transformation. It only took 2 min to obtain response results. For measuring the exocytosis H2O2 from living cells, we observed a good linear relationship between the visual/digital signal and logarithmic function of MCF-7 cell counts. Furthermore, the fitted half inhibitory concentration curve of MCF-7 to doxorubicin hydrochloride obtained by the BP-LED-E-LDR device revealed a nearly identical tendency with the cell counting kit-8 assay, providing an attainable, reusable, and robust analytical strategy for evaluating cell viability in drug toxicology research.

Laser treatment for Cafe-au-lait Macules: a systematic review and meta-analysis.

Nowadays, laser is the mainstay treatment for cafe-au-lait macules (CALMs), but no systematic review has been published to demonstrate the overall efficacy and it's still controversial which type of laser is optimal. Thus, we conduct the meta-analysis to evaluate the effectiveness and side effects of various types of lasers in treating CALMs. Original articles reporting the efficacy and side effects for CALMs in laser treatment were identified in PubMed, EMBASE, and Web of Science from 1983 to April 11, 2023. Using R software and the 'meta' package, meta-analysis was conducted for clearance and recurrence for evaluation of efficacy. And the occurrence of hypopigmentation and hyperpigmentation rate was pooled for safety evaluation. We used RoB2 and ROBINS-I tools to assess the risks of bias in RCT studies and non-RCT studies, respectively. The Grading of Recommendations, Assessment, Development and Evaluation system was used to assess the quality of the evidence. Nineteen studies involving 991 patients were included, which had a very low to moderate quality of evidence. The pooled 75% clearance rate was 43.3% (95% CI 31.8-54.7%, I2 = 96%), 50% clearance rate was 75% (95% CI 62.2-85.9%, I2 = 89%) and the recurrence rate was 13% (95% CI 3.2-26.5%, I2 = 88%). The pooled hypopigmentation and hyperpigmentation rates were 1.2% (95% CI 0.3-2.1%, I2 = 0%) and 1.2% (95% CI 0.3-2%, I2 = 0%), respectively. Subgroup analysis revealed that QS-1064-nm Nd:YAG laser treatment not only achieved more than 75% clearance rate in 50.9% of patients (95% CI 26.9-74.4%, I2 = 90%) but also resulted in the lowest hypopigmentation and hyperpigmentation rate of 0.5% (95% CI 0.0-2.5%, I2 = 26%) and 0.4% (95% CI 0.0-2.5%, I2 = 0%). To draw a conclusion, the laser treatment could reach an overall clearance rate of 50% for 75% of the patients with CALMs, for 43.3% of the patients, the clearance rate could reach 75%. When looking at different wavelength subgroups, QS-1064-nm Nd:YAG laser exhibited the best treatment capability. Laser of all the wavelength subgroups presented acceptable safety regarding of the low occurrence of side effects, namely, hypopigmentation and hyperpigmentation.

Integrated paper-based 3D platform for long-term cell culture and in situ cell viability monitoring of Alzheimer's disease cell model.

Reactive oxygen species including superoxide anion, hydrogen peroxide (H2O2) and hydroxyl radicals, as a conflicting class of biological metabolites in living organism, act crucial effect on Alzheimer's disease (AD). In this work, a facile integrated platform composed of a paper-based three-dimension (3D) cell culture system and an electrochemical sensor was developed for the construction of AD cell model in third dimensional structure and in situ cell viability monitoring by H2O2 released from PC12 cells cultured on paper scaffold were divided into three groups containing control group, amyloid beta peptide 25-35 (Aß25-35) group and Aß25-35+curcumin (Aß25-35+cur) group, respectively. In addition, the paper-based 3D platform displayed excellent properties, such as sensitivity, selectivity, reproducibility and stability. The levels of H2O2 expressed in PC12 cells of the three groups were monitored through a paper-based 3D platform. The viability of cells cultured on the 96-well plate was measured by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Results of this paper-based platform are consistent with those of MTT, both displaying improved cell viability and decreased H2O2 production in Aß25-35+cur group compared to Aß25-35 group, which indicates that curcumin has effective cytoprotection. The paper-based 3D platform provides a convenient, economic and universal platform for in situ cell activity monitoring by key small molecules released from living cells.

Paper-based 3D culture device integrated with electrochemical sensor for the on-line cell viability evaluation of amyloid-beta peptide induced damage in PC12 cells.

In this communication, a paper-based 3D cell culture device integrated with electrochemical biosensor was applied to on-line monitoring of dopamine release from PC12 cell damage models induced by amyloid-beta peptide (Aß25-35) and cell intervene models protected by curcumin (Cur) and marrow mesenchymal stem cells (MSC) supernatant. The adhesion and proliferation of PC12 cells cultured on the paper scaffold was characterized by scanning electron microscopy and laser scanning confocal microscopy, which verify unique biocompatibility and 3D microarchitecture similar to human body microenvironment of paper substrate, so an artificial model simulating 3D microenvironment in vivo was constructed easily. The PC12 cells in paper-based devices consisted of four groups containing control group, Aß25-35 group, Aß25-35+Cur group and Aß25-35+MSC supernatant group. Under optimal conditions, this proposed device displayed a wide linear range from 0.05 to 1 µmol/L with a detection limit of 0.009 µmol/L (S/N = 3) and exhibited high sensitivity, good selectivity and excellent reproducibility. Furtherly, electrochemcial analysis and MTT assay gave a clue that the cell viability of Aß25-35+MSCs supernatant group was higher than that of Aß25-35+Cur group. Therefore, the detachable paper-based 3D device paves the way to a direct detection of exocytosis DA from neuron cells for on-line cell viability evaluation of neurodegenerative disease cell damage models.

A colorimetric assay for sensitive detection of hydrogen peroxide and glucose in microfluidic paper-based analytical devices integrated with starch-iodide-gelatin system.

Microfluidic paper-based analytical devices (µPADs) for detection of hydrogen peroxide and glucose have been developed. The analytical performance of colorimetric detection using the conventional starch-iodine color reaction has been significantly improved by using gelatin as the surface modifier which retains the enzyme activity in the dry filter paper strip, improves antioxidability, as well as decreases the strong background signal. Under optimal conditions, the color intensities show a good linear relationship with glucose concentration ranging from 0.5 to 5 mM and hydrogen peroxide concentration from 0.5 to 6 mM, with the detection limit of 0.05 mM and 0.1 mM, respectively. In addition, the accuracy of colorimetric sensor has been successfully assessed in detecting glucose from real human serum samples and recovery value ranges from 95.7% to 97%, which are approaching to the glucose oxidase endpoint. The new colorimetric assay exhibits high sensitivity, good selectivity, acceptable stability and reproducibility. The present approach is promising for monitoring glucose for point of care diagnostic applications, especially in regions with resource-limited settings.