In Situ Cancer-Cell-Triggered Visible Changes in Mechanical Properties, Electroconductivity, and Adhesiveness of a MnO2@PD-Based Mineralized Hydrogel.

Herein, a cancer-specific dopamine-conjugated sp2-rich carbonized polymer dot (PD)-encapsulated mesoporous MnO2 (MnO2@PD)-mineralized hydrogel biosensor was developed that offers cancer-induced observable in situ alterations in fluorescence (FL), electrochemical, and mechanophysical properties. Cancer-triggered MnO2 degradation in the hydrogel, prompted by increased levels of glutathione (GSH) and reactive oxygen species (ROS) such as H2O2, leads to PD release and FL restoration, thereby controlling changes in the pore structure and increasing hydrogen bonding, resulting in physiologically visible alterations in mechanical stretchability, viscosity, swelling behavior, and adhesiveness. The pore size of the matrix increased from 21.83 to 36.81 m2/g upon GSH treatment, affecting the viscosity and swellability of the system. The resistance increased from 21.96 ± 1.16 to 30.69 ± 2.01 and 32.21 ± 2.54 kΩ, respectively, confirming the dependence of conductivity changes on H2O2 and GSH treatments. The in vitro treatment with cancer cells (HeLa, PC-3, and B16F10) facilitated a tunable electrochemical sensing performance via redox-mediated MnO2 breakdown by intracellular ROS and GSH, whereas hydrogels treated with normal cells (CHO-K1) showed minimal changes. Cancer-microenvironment-derived water-drop sensing showed three times higher response as compared to the normal cell-treated hydrogel. The sensing capability of the fabricated sensor was validated based on bending-induced relative resistance changes under dry and wet conditions. Moreover, the integration of the developed sensor with a wireless sensor enabled real-time monitoring with a smartphone.

Electrochemical and fluorescent dual-mode sensor of acetylcholinesterase activity and inhibition based on MnO2@PD-coated surface.

We developed an electrochemical and fluorescent dual-mode sensor for assessing acetylcholinesterase (AChE) activity and inhibition by taking advantage of the high redox sensitivity of surface-coated mesoporous MnO2@polymer dot (MnO2@PD) towards AChE. The following phenomena constitute the basis of the detection mechanism: fluorescence resonance energy transfer (FRET) effect between MnO2 and PD; catalytic hydrolysis of acetylthiocholine (ATCh) to thiocholine (TCh) by AChE expressed by PC-12 cells, inducing fluorescence restoration and change in the conductivity of the system due to MnO2 decomposition; the presence of the inhibitor neostigmine preventing the conversion of ATCh to TCh. The surface-coated biosensor presents both fluorescence-based and electrochemical approaches for effectively monitoring AChE activity and inhibition. The fluorescence approach is based on the fluorescent "on/off" property of the system caused by MnO2 breakdown after interaction with TCh and the subsequent release of PDs. The conductivity of the coated electrode decreased dramatically as AChE concentration increased, resulting in electrochemical sensing of AChE activity and inhibition screening. Real-time wireless sensing can be conducted using a smartphone to monitor the resistance change, investigating the potential use of MnO2@PD nanocomposites in biological studies, and offering a real-time redox-fluorescent test for AChE activity monitoring and inhibitor screening.

Study on the prevalence of intestinal parasitic infections and the assessment of the efficacy of albendazole in soil-transmitted helminths in school-going children in East Sikkim.

BACKGROUND: The problem of intestinal parasitic infections (IPIs) in children is one of the most worrisome problems worldwide. The latest estimates indicate that more than 880 million children are in the need of treatment for these parasites. OBJECTIVE: The aim of this study was to measure the prevalence of IPIs in school-going children in East Sikkim, India, and to assess the efficacy of single-dose albendazole (ALB) in children infected with soil-transmitted helminths (STHs). SUBJECTS AND METHODS: A total of 300 stool samples were collected from the schoolchildren of government schools of East Sikkim. Samples were processed for the identification of IPIs by direct microscopy and formalin-ether concentration method. Fecal egg counting was carried out for STH by Stoll's egg counting technique, pre- and posttreatment with single-dose ALB. The second stool samples were collected 10-14 days posttreatment of ALB. Cure rate (CR) and the fecal egg reduction rate (ERR), the two most widely used indicators for assessing the efficacy of an anthelmintic, were used in this study. The data were analyzed and the results were interpreted statistically. RESULTS: The overall prevalence of the IPIs was 33.9%. Helminthic infection was 4.6% and protozoan infection was 29.3%. Among helminthes Ascaris lumbricoides and among protozoans Entamoeba spp. were the dominant intestinal parasites. For drug efficacy, A. lumbricoides had CR 55.5% and ERR 81.4%. Moreover, for Trichuris trichiura, CR and ERR was 100%. The study has shown less efficacy against A. lumbricoides infections compared to T. trichiura. CONCLUSION: The study provides useful insight into the current prevalence of IPIs in school-going children in government schools in East Sikkim region. Keeping in view of less efficacy of ALB, it is necessary to keep the monitoring of development of drug resistance simultaneously.