Simple and Cost-Effective Generation of 3D Cell Sheets and Spheroids Using Curvature-Controlled Paraffin Wax Substrates.

The challenges associated with animal testing in pharmaceutical development have driven the search for alternative in vitro models that mimic human tissues more accurately. In this study, we present a simple and cost-effective method for generating 3D cell sheets and spheroids using curvature-controlled paraffin wax films, which are easily accessible laboratory materials that eliminate the need for extracellular matrix (ECM) components or thermo-responsive polymers. By adjusting the curvature of the paraffin wax film, we successfully generated human periodontal ligament fibroblast (HPdLF) cell sheets and bone marrow-derived mesenchymal stem cell (hBMSC) spheroids.

Recent Advances in Nanomaterials for Modulation of Stem Cell Differentiation and Its Therapeutic Applications.

Challenges in directed differentiation and survival limit the clinical use of stem cells despite their promising therapeutic potential in regenerative medicine. Nanotechnology has emerged as a powerful tool to address these challenges and enable precise control over stem cell fate. In particular, nanomaterials can mimic an extracellular matrix and provide specific cues to guide stem cell differentiation and proliferation in the field of nanotechnology.

Recent Advances in Electrochemical Detection of Cell Energy Metabolism.

Cell energy metabolism is a complex and multifaceted process by which some of the most important nutrients, particularly glucose and other sugars, are transformed into energy. This complexity is a result of dynamic interactions between multiple components, including ions, metabolic intermediates, and products that arise from biochemical reactions, such as glycolysis and mitochondrial oxidative phosphorylation (OXPHOS), the two main metabolic pathways that provide adenosine triphosphate (ATP), the main source of chemical energy driving various physiological activities. Impaired cell energy metabolism and perturbations or dysfunctions in associated metabolites are frequently implicated in numerous diseases, such as diabetes, cancer, and neurodegenerative and cardiovascular disorders.

Extracellularly Detectable Electrochemical Signals of Living Cells Originate from Metabolic Reactions.

Direct detection of cellular redox signals has shown immense potential as a novel living cell analysis tool. However, the origin of such signals remains unknown, which hinders the widespread use of electrochemical methods for cellular research. In this study, the authors found that intracellular metabolic pathways that generate adenosine triphosphate (ATP) are the main contributors to extracellularly detectable electrochemical signals.

Recent Advances in Electrochemical Biosensors for Monitoring Animal Cell Function and Viability.

Redox reactions in live cells are generated by involving various redox biomolecules for maintaining cell viability and functions. These qualities have been exploited in the development of clinical monitoring, diagnostic approaches, and numerous types of biosensors. Particularly, electrochemical biosensor-based live-cell detection technologies, such as electric cell-substrate impedance (ECIS), field-effect transistors (FETs), and potentiometric-based biosensors, are used for the electrochemical-based sensing of extracellular changes, genetic alterations, and redox reactions.

Gold nanostructure-integrated conductive microwell arrays for uniform cancer spheroid formation and electrochemical drug screening.

Cancer spheroids, which mimic distinct cell-to-cell and cell-extracellular matrix interactions of solid tumors in vitro, have emerged as a promising tumor model for drug screening. However, owing to the unique characteristics of spheroids composed of three-dimensionally densely-packed cells, the precise characterizations of cell viability and function with conventional colorimetric assays are challenging. Herein, we report gold nanostructure-integrated conductive microwell arrays (GONIMA) that enable both highly efficient uniform cancer spheroid formation and precise electrochemical detection of cell viability.

Label-free and non-destructive identification of naïve and primed embryonic stem cells based on differences in cellular metabolism.

Pluripotent stem cells (PSCs) exist in naïve or primed states based on their origin. For in vitro culture, these PSCs require different supplements and growth factors. However, owing to their similar phenotypic features, identifying both cell types without harming cellular functions is challenging.

Electrically controlled mRNA delivery using a polypyrrole-graphene oxide hybrid film to promote osteogenic differentiation of human mesenchymal stem cells.

Unlabelled: Direct messenger ribonucleic acid (mRNA) delivery to target cells or tissues has revolutionized the field of biotechnology. However, the applicability of regenerative medicine is limited by the technical difficulties of various mRNA-loaded nanocarriers. Herein, we report a new conductive hybrid film that could guide osteogenic differentiation of human adipose-derived mesenchymal stem cells (hADMSCs) via electrically controlled mRNA delivery.

Hybrid and Etch-Less Electrooptic Waveguide Modulator Based on Photo-Bleaching and Strain Induced Optical Waveguide Technique in Polymer.

A hybrid and etchless electrooptic (EO) polymer waveguide modulator based on both a photo-bleaching-induced optical waveguide (PBOW) and a strain-induced optical waveguide (SIOW) is described. The SIOW is defined by a metal strip line stressor deposited on top of the upper cladding that introduces the refractive index change within the core region. The PBOW technique is used to form an optical waveguide which is based on a photo-bleaching process, known as a photo-oxidation that is an irreversible decomposition of EO material, resulting in a permanent decrease in index of refraction.