Volume 7 (2023): Issue 3 (July 2023)

This study aimed to modify screen-printed carbon micro-electrode surfaces by coating them with multiwall carbon-based nanotubes conjugated with chitosan and then validated the formed multiwall carbon-based nanotubes-chitosan coated screen printed carbon micro-electrode for the detection of homocysteine, a biomarker analyte known as a risk indicator in cardiovascular disease. The microstructure surface and crystallographic structure stability of the formed multiwall carbon-based nanotubes-chitosan obtained at formed multiwall carbon-based nanotubes per chitosan ratios of 1:1, 2:1, 3:1, and 4:1 were examined via field emission scanning electron microscopy, X-ray radiation, Raman spectroscopy, surface area and pore size, and thermogravimetric analyses. Homocysteine solutions at 30–100 µM were measured by cyclic voltammetry using the different formed multiwall carbon-based nanotubes-chitosan compositions as sensor electrodes. That with an optimal formed multiwall carbon-based nanotubes per chitosan ratio of 4:1 showed the highest crystallinity and electrical conductivity and gave a high coefficient of determination (R² = 0.9036) between the homocysteine concentration and the oxidation current detection over an operating range of 30–100 µM. This new composite microelectrode for detecting homocysteine concentration makes it a promising candidate for clinical applications.

The study has developed a model splicing construct assay system based on splicing misregulation, one of the major molecular features associated with myotonic dystrophy. The splicing construct assay has double reporters for intron 2 splicing in chloride channel (CLCN1). The CLCN1 transgene splicing construct assay was used to transfect wild type and DM fibroblast cell lines and the clones generated showed that it enabled quantification of splicing efficiency in transgene construct. Validation of the DM fibroblasts containing transgene splicing construct was performed by differentiating the DM fibroblasts into myoblasts which exhibited a switch in CLCN1 splicing construct which was consistent with that associated with myotonic dystrophy (DM) condition. The myoblast derived from fibroblasts cell-based gene-splicing assay was subsequently applied in therapeutic screening in small throughput screens of 113 compounds which identified Protein Kinase C inhibitors- hypericin and Ro-31-8220 as potential therapeutic agents. The CLCN1 gene-splicing assay is a good model system for application in therapeutic screening in myotonic dystrophy because its double reporters facilitated quantification of effect putative drug on correction of misregulated splicing.