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.

Bandgap Engineering in 2D Lateral Heterostructures of Transition Metal Dichalcogenides via Controlled Alloying.

2D heterostructures made of transition metal dichalcogenides (TMD) have emerged as potential building blocks for new-generation 2D electronics due to their interesting physical properties at the interfaces. The bandgap, work function, and optical constants are composition dependent, and the spectrum of applications can be expanded by producing alloy-based heterostructures. Herein, the successful synthesis of monolayer and bilayer lateral heterostructures, based on ternary alloys of MoS Se -WS Se , is reported by modifying the ratio of the source precursors; the bandgaps of both materials in the heterostructure are continuously tuned in the entire range of chalcogen compositions.

Extremely Uniform Graphene Oxide Thin Film as a Universal Platform for One-Step Biomaterial Patterning.

Graphene oxide (GO) has proven to be a highly promising material across various biomedical research avenues, including cancer therapy and stem cell-based regenerative medicine. However, creating a uniform GO coating as a thin layer on desired substrates has been considered challenging owing to the intrinsic variability of the size and shape of GO. Herein, a new method is introduced that enables highly uniform GO thin film (UGTF) fabrication on various biocompatible substrates.

Raman Spectroscopy-Based 3D Analysis of Odontogenic Differentiation of Human Dental Pulp Stem Cell Spheroids.

Numerous efforts have been made to establish three-dimensional (3D) cell cultures that mimic the structure, cell composition, and functions of actual tissues and organs ; however, owing to its intrinsic complexity, precise characterization of 3D differentiation remains challenging and often results in high variations in the resulting differentiated spheroids. This study reports a 3D Raman mapping-based analytical method that helps us to identify the crucial factors responsible for inducing variability in differentiated stem cell spheroids. Human dental pulp stem cell spheroids were generated at various cell densities using the hanging drop (HD) and molded parafilm-based (MP) methods and were then further subjected to odontogenic differentiation.

Enhancing osteogenesis of adipose-derived mesenchymal stem cells using gold nanostructure/peptide-nanopatterned graphene oxide.

Graphene derivatives are highly promising materials for use in stem-cell-based regenerative therapies, particularly for bone regeneration. Herein, we report a graphene oxide (GO)-based hybrid platform (GOHP) that is highly effective for guiding the osteogenesis of human adipose-derived mesenchymal stem cells (hAMSCs). A GO-coated indium tin oxide (ITO) substrate was electrochemically modified with Au nanostructures (GNSs), following which a cysteine-modified quadruple-branched arginine-glycine-aspartic acid was self-assembled on the ITO-GO-GNS hybrid via Au-S bonds.

Autofluorescence-Raman Mapping Integration analysis for ultra-fast label-free monitoring of adipogenic differentiation of stem cells.

Stem cell-based therapies have recently emerged to treat various incurable diseases and disorders. Types of stem cell-derived cells and their functions should be intensively analyzed before therapy. However, current pre-treatment steps for biological analysis are mostly destructive.

Facile Morphological Qualification of Transferred Graphene by Phase-Shifting Interferometry.

Post-growth graphene transfer to a variety of host substrates for circuitry fabrication has been among the most popular subjects since its successful development via chemical vapor deposition in the past decade. Fast and reliable evaluation tools for its morphological characteristics are essential for the development of defect-free transfer protocols. The implementation of conventional techniques, such as Raman spectroscopy, atomic force microscopy (AFM), and transmission electron microscopy in production quality control at an industrial scale is difficult because they are limited to local areas, are time consuming, and their operation is complex.

Vertically Coated Graphene Oxide Micro-Well Arrays for Highly Efficient Cancer Spheroid Formation and Drug Screening.

Research on the 3D culturing of cancer cells that better mimic in vivo solid tumors is important for efficient drug screening. Herein, a new platform that effectively facilitates the formation of cancer spheroids for anticancer drug screening is reported. Cytophilic graphene oxide (GO), when selectively coated on the sidewalls of micro-wells fabricated from a cell-adhesion-resistive polymer, is found to efficiently initiates distinct donut-like formation of cancer cell spheroids.

Time Evolution Studies on Strain and Doping of Graphene Grown on a Copper Substrate Using Raman Spectroscopy.

The enhanced growth of Cu oxides underneath graphene grown on a Cu substrate has been of great interest to many groups. In this work, the strain and doping status of graphene, based on the gradual growth of Cu oxides from underneath, were systematically studied using time evolution Raman spectroscopy. The compressive strain to graphene, due to the thermal expansion coefficient difference between graphene and the Cu substrate, was almost released by the nonuniform CuO growth; however, slight tensile strain was exerted.

Three-Dimensional Graphene-RGD Peptide Nanoisland Composites That Enhance the Osteogenesis of Human Adipose-Derived Mesenchymal Stem Cells.

Graphene derivatives have immense potential in stem cell research. Here, we report a three-dimensional graphene/arginine-glycine-aspartic acid (RGD) peptide nanoisland composite effective in guiding the osteogenesis of human adipose-derived mesenchymal stem cells (ADSCs). Amine-modified silica nanoparticles (SiNPs) were uniformly coated onto an indium tin oxide electrode (ITO), followed by graphene oxide (GO) encapsulation and electrochemical deposition of gold nanoparticles.

In situ label-free monitoring of human adipose-derived mesenchymal stem cell differentiation into multiple lineages.

Precise characterizations of stem cell differentiation into specific lineages, especially in non-destructive and non-invasive manner, are extremely important for generating patient-specific cells without mass loss of differentiated cells. Here, we report a new method capable of in situ label-free quantification of stem cell differentiation into multiple lineages, even at a single cell level. The human adipose-derived mesenchymal stem cells (hADMSCs) were first differentiated into two different types of cells (osteoblasts and adipocytes) and these differentiated cells were then intensively analyzed by micro-Raman spectroscopy.

Effects of two-dimensional materials on human mesenchymal stem cell behaviors.

Graphene, a typical two-dimensional (2D) material, is known to affect a variety of stem cell behaviors including adhesion, spreading, growth, and differentiation. Here, we report for the first time the effects of four different emerging 2D materials on human adipose-derived mesenchymal stem cells (hADMSCs). Graphene oxide (GO), molybdenum sulfide (MoS), tungsten sulfide (WS), and boron nitride (BN) were selected as model two-dimensional materials and were coated on cell-culture substrates by a drop-casting method.