Influence of nanoparticle shape, size, and surface functionalization on cellular uptake.

With the rapid development of biotechnology and nanomedicine, extensive research has focused on the investigations of delivering large-cargo molecules using nanoparticles through the cell membrane for disease diagnosis and treatment. Various inorganic and polymeric nanoparticles with optimized surface properties have been developed to carry these active cargo molecules such as organic molecules, oligonucleotides and proteins. Phagocytosis and pinocytosis have been suggested as the two major uptake mechanisms for nanoparticles to enter into cellular interior, but such mechanisms are still under debate. In order to enhance the efficiency of cellular uptake of nanoparticles and further understand the physiological process, it is important to investigate detailed interaction mechanisms between nanoparticles and cell membranes. Here, we will review the recent advances of the effect of nanoparticle properties (e.g., nanoparticle shape, size, charge, surface modification, etc.) on cellular uptake mechanisms. These will aid in the future design and development of nanoparticles with improved surface properties for drug and biomolecule delivery. Up to now, novel analytical techniques have been used to examine nanoparticle-cell membrane interactions, but their detailed uptake mechanisms and pathways still need more in-depth research. It is suggested that developing appropriate analytical techniques to study cellular uptake mechanisms of nanoparticles in real time is urgently desired.

Magnetic nanoparticles-based extraction and verification of nucleic acids from different sources.

In many molecule biology and genetic technology studies, the amount of available DNA can be one of the important criteria for selecting the samples from different sources. Compared with those genomic DNA methods using organic solvents or other traditional commercial kits, the method based on magnetic nanoparticles (MNPs) and adsorption technology has many remarkable advantages like being time-saving and cost effective without the laborious centrifugation or precipitation steps, and more importantly it has the great potential and especially suitable for automated DNA extraction and up-scaling. In this paper, the extraction efficiency of genomic nucleic acids based on magnetic nanoparticles from four different sources including bacteria, yeast, human blood and virus samples are compared and verified. After measurement and verification of the extracted genomic nucleic acids, it was shown that all these genomic nucleic acids extracted using the MNPs method can be of high yield and be available for next molecule biological steps.

Preparation and biomedical applications of core-shell silica/magnetic nanoparticle composites.

Core-shell structured silica/magnetic nanoparticle composites have recently been subjected to extensive research since the shells could offer protection to the cores and introduce new properties to the hybrid structures, which endue them with great application potentials in various fields. Several approaches have been studied for the synthesis of SiO2 coated on magnetic nanoparticles. These approaches include Stöber process, microemulsion, sodium silicate and tetraethoxysilane hydrolysis, aerosol pyrolysis, layer-by-layer strategy, polymer-templating and sonochemical deposition. This review is focused on describing state-of-the-art synthetic routes and methods for the preparation of silica/magnetic nanoparticle composites. Furthermore, we also introduce main applications of these nanoparticle composites in biomedical scopes and address some challenges in the synthesis of high-quality magnetic nanoparticles.