Bead-Immobilized Multimodal Molecular Beacon-Equipped DNA Machinery for Specific RNA Target Detection: A Prototypical Molecular Nanobiosensor

A Reverse Transfection System with Cationized Gelatin Nanospheres Incorporating Molecular Beacon as a Tool to Visualize Cell Function

The objective of this research is to design a reverse transfection system with cationized gelatin nanospheres (cGNS) incorporating a molecular beacon (MB) to visualize a cell function. The cGNS were prepared by the conventional coacervation method. The MB as an imaging probe was incorporated into the cGNS to prepare imaging complexes (cGNSMB). The conventional transfection of 2D culture was performed by incubating MC3T3 cells in the medium containing cGNSMB. The reverse transfection was done by incubating cells on the substrate which had been precoated with both gelatin and cGNSMB. Significantly higher internalization efficiency and fluorescence intensity of cGNSMB were observed in the reverse transfection system than in the conventional one. To apply this system for visualization of 3D cell aggregate, gelatin microspheres (GMS) were prepared, while cGNSMB were bound on the GMS to prepare the GMS-cGNSMB of a cell scaffold. Then the cells were incubated with GMS-cGNSMB to form 3D cell aggregates. On the other hand, as a control, the conventional transfection of 3D culture was performed by incubating the cell aggregates formed with the medium containing cGNSMB. Homogeneous fluorescence of MB from the inside to the outside of aggregates was observed for the reverse transfection group. However, for the conventional transfection, the fluorescence was observed only around the surface of cell aggregates. It is concluded that the reverse transfection system with cGNS incorporating MB is promising to visualize the cell function of a higher transfection efficiency for the 2D culture and in a homogeneous manner for the 3D culture.

Role of Nano-miRNAs in Diagnostics and Therapeutics

MicroRNAs (miRNA) are key regulators of gene expression, controlling different biological processes such as cellular development, differentiation, proliferation, metabolism, and apoptosis. The relationships between miRNA expression and the onset and progression of different diseases, such as tumours, cardiovascular and rheumatic diseases, and neurological disorders, are well known. A nanotechnology-based approach could match miRNA delivery and detection to move beyond the proof-of-concept stage. Different kinds of nanotechnologies can have a major impact on the diagnosis and treatment of miRNA-related diseases such as cancer. Developing novel methodologies aimed at clinical practice represents a big challenge for the early diagnosis of specific diseases. Within this context, nanotechnology represents a wide emerging area at the forefront of research over the last two decades, whose potential has yet to be fully attained. Nanomedicine, derived from nanotechnology, can exploit the unique properties of nanometer-sized particles for diagnostic and therapeutic purposes. Through nanomedicine, specific treatment to counteract only cancer-cell proliferation will be improved, while leaving healthy cells intact. In this review, we dissect the properties of different nanocarriers and their roles in the early detection and treatment of cancer.

Static and Free Vibration Analyses of Single-Walled Carbon Nanotube (SWCNT)–Substrate Medium Systems

This paper proposes a novel nanobar–substrate medium model for static and free vibration analyses of single-walled carbon nanotube (SWCNT) systems embedded in the elastic substrate medium. The modified strain-gradient elasticity theory is utilized to account for the material small-scale effect, while the Gurtin–Murdoch surface theory is employed to represent the surface energy effect. The Winkler foundation model is assigned to consider the interactive mechanism between the nanobar and its surrounding substrate medium. Hamilton’s principle is used to consistently derive the system governing equation, initial conditions, and classical as well as non-classical boundary conditions. Two numerical simulations are employed to demonstrate the essence of the material small-scale effect, the surface energy effect, and the surrounding substrate medium on static and free vibration responses of single-walled carbon nanotube (SWCNT)–substrate medium systems. The simulation results show that the material small-scale effect, the surface energy effect, and the interaction between the substrate and the structure led to a system-stiffness enhancement both in static and free vibration analyses.