Nanoparticle embedded chitosan film for agglomeration free TEM images

Abstract

Transmission electron microscopy (TEM) is a very useful and commonly used microscopy technique, used especially for the characterization of nanoparticles. However, the identification of the magnetic nanoparticle could be thought problematic in TEM analysis, due to the fact that the magnetic nanoparticles are usually form aggregates on the TEM grid to form bigger particles generating higher stability. This prevents to see exact shape and size of each nanoparticle. In order to overcome this problem, a simple process for the formation of well-dispersed nanoparticles was conducted, by covering chitosan film on the unmodified copper grid, it was said to result in aggregation-free TEM images. It is also important to fix the magnetic nanoparticles on the TEM grids, due to possible contamination of TEM filament which is operated under high vacuum conditions. The chitosan film matrix also helps to protect the TEM filament from contact with magnetic nanoparticles during the imaging process. The proposed procedure offers a quick method to fix the nanoparticles in a conventional copper TEM grid and chitosan matrix prevents agglomeration of nanoparticles, and thus getting TEM images showing well-dispersed individual nanoparticles.

One-pot hydrothermal synthesis of a magnetic hydroxyapatite nanocomposite for MR imaging and pH-Sensitive drug delivery applications

“…The rod-like morphology of the IO-HA, which is due to the hydroxyapatite part of the nanocomposite, as well as being iron oxide nanoparticles as black dots on the surfaces of the hydroxyapatite nanorods are quite clear [ 28 , 29 ]. The sample preparation for TEM observation may induce some aggregation of the magnetic particles during deposition on a grid, which is not unexpected due to the magnetic nature of the nanoparticles [ 30 ].

Figure 3 (A, B) TEM images of IO-HA nanocomposite and size distribution (C).

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Increased Cytotoxic Efficacy of Protocatechuic Acid in A549 Human Lung Cancer Delivered via Hydrophobically Modified-Chitosan Nanoparticles As an Anticancer Modality

“…Such a phenomenon has been described as a consequence of the mechanical forces during synthesis. Dogan et al reported that the aggregation of nanoparticles can occur during drying of samples on the TEM grid prior to observation [ 73 ]. Additionally, there exist some nanoparticles with sizes similar to CNP and pCNP observed in Figure 5 C,D.…”

Progress in copper‐based materials for wound healing

“…53 Cu NPs are prone to rapid oxidation and agglomeration during its use. 54 The cytotoxicity was more obvious with the increase of nanoparticle concentration. This may be due to increased ROS production, genotoxicity, and multiple exogenous resistance transporter activities.…”

“…At the same time, because the nanoparticles have an active surface, it can easily passes through a biomembrane and destroys cell tissues 53 . Cu NPs are prone to rapid oxidation and agglomeration during its use 54 . The cytotoxicity was more obvious with the increase of nanoparticle concentration.…”