Aimed at utilizing high-magnetization nanospheres for magnetic field-enhanced cellular labeling, core-shell structured sandwich-like magnetic mesoporous silica nanospheres were developed. While the magnetite cluster core can provide a high magnetic response for overcoming Brownian motion in cell culture media, the layered silica shell facilitates an efficient fluorescent dye labeling. However, the problem of particle aggregation in cell media, which is strongly enhanced under a magnetic field, significantly impeded the uptake by cells, resulting in difficulties in the precise analysis of the degree of particle internalization by fluorescence-based techniques (flow cytometry and confocal microscopy). To overcome this, reflection-based assessment was employed. Further, emphasis was put on utilizing the unique role of surface-hyperbranched polyethylenimine (PEI) in efficient prevention of particle aggregation prior to cell internalization in the presence of an external magnetic field. The interparticle attraction forces originating from magnetic dipole-dipole interactions are hereby balanced by the steric and electrostatic repulsion forces provided by the PEI functionalization, which leads to dispersed nanospheres in cell culture media during the magnetic-field induced cell labeling. As a consequence, PEI functionalization and the presence of the magnetic field synergistically enhanced the efficiency of MRI-fluorescence dual-mode labeling for cellular tracking.

Download full-text PDF

Source
http://dx.doi.org/10.1039/c4bm00221kDOI Listing

Publication Analysis

Top Keywords

magnetic field
16
cellular labeling
8
magnetic
8
cell culture
8
culture media
8
particle aggregation
8
pei functionalization
8
labeling
5
cell
5
combination magnetic
4

Similar Publications

Backbone resonance assignments of PhoCl, a photocleavable protein.

Biomol NMR Assign

January 2025

High Magnetic Field Laboratory, Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, China.

PhoCl is a photocleavable protein engineered from a green-to-red photoconvertible fluorescent protein by circular permutation, and has been used in various optogenetic applications including precise control of protein localization and activity in cells. Upon violet light illumination, PhoCl undergoes a β-elimination reaction to be cleaved at the chromophore, resulting in spontaneous dissociation into a large empty barrel and a small C-terminal peptide. However, the structural determinants and the mechanism of the PhoCl photocleavage remain elusive, hindering the further development of more robust photocleavable optogenetic tools.

View Article and Find Full Text PDF

Flexible Tactile Sensors with Self-Assembled Cilia Based on Magnetoelectric Composites.

ACS Appl Mater Interfaces

January 2025

School of Precision Instrument and Optoelectronics Engineering, Tianjin University, 92 Weijin Road, Tianjin 300072, China.

Traditional tactile sensors are single-function, and it is difficult to meet the needs of applications in complex environments. This paper describes the development and applications of flexible tactile sensors with cilia based on magnetoelectric composites made of neodymium iron boron (NdFeB) microparticles with a silver (Ag) nanoshell in polydimethylsiloxane (PDMS). These sensors adopt the inherent magnetism of NdFeB microparticles and the excellent conductivity of the Ag coating.

View Article and Find Full Text PDF

Aggregation intermediates play a pivotal role in the assembly of amyloid fibrils, which are central to the pathogenesis of neurodegenerative diseases. The structures of filamentous intermediates and mature fibrils are now efficiently determined by single-particle cryo-electron microscopy. By contrast, smaller pre-fibrillar α-Synuclein (αS) oligomers, crucial for initiating amyloidogenesis, remain largely uncharacterized.

View Article and Find Full Text PDF

Ubiquitin-A structural perspective.

Mol Cell

January 2025

Ubiquitin Signalling Division, WEHI, Melbourne, VIC, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia. Electronic address:

The modification of proteins and other biomolecules with the small protein ubiquitin has enthralled scientists from many disciplines for decades, creating a broad research field. Ubiquitin research is particularly rich in molecular and mechanistic understanding due to a plethora of (poly)ubiquitin structures alone and in complex with ubiquitin machineries. Furthermore, due to its favorable properties, ubiquitin serves as a model system for many biophysical and computational techniques.

View Article and Find Full Text PDF

Inclusion of α-Linolenic acid ethyl ester in flaxseed oil with β-Cyclodextrin by hydrogen bonding.

Food Chem

January 2025

Research Center of Grain and Oil Functionalized Processing in Universities of Shaanxi Province, College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling 712100, Shaanxi, PR China. Electronic address:

β-Cyclodextrin (β-CD) enhances functional properties by forming inclusion complexes (ICs). This study employed β-CD to form IC with fatty acid ethyl ester (FAEE) for concentrating α-Linolenic acid ethyl ester (ALAEE) from flaxseed oil FAEE, and investigated the interaction mechanisms between β-CD and ALAEE. Using the single-factor method, optimal inclusion conditions yielded an inclusion rate of 61.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!