Nano Dispersion

Nanopowder generally refers to powder or particles with a particle size of fewer than 100 nanometers. It is a solid particle material in an intermediate state between atoms, molecules and macroscopic objects. Nano-dispersion refers to the dispersion of one or several kinds of nanoparticles in another substance to form a nanoparticle dispersion. Due to the large specific surface area and high surface energy of nano-powders, in the process of preparation and use, particles are easily agglomerated to form secondary particles, which increase the particle size and lose the functions of nano-particles. Therefore, it is necessary to disperse the nanopowder.


    • As the carrier of anti-tumor drugs: Nanocarriers can significantly prolong the action time of drugs in the body and change their distribution in the body, which is very beneficial for the treatment of natural targets (such as liver, spleen, etc.). Therefore, nanocarriers can increase the concentration and residence time of anti-tumor drugs at the tumor site, thereby enhancing the efficacy and reducing side effects. For example, loading doxorubicin into PLGA nano dispersion, PLGA with high relative molecular mass is conducive to the slow release of drugs, thereby inhibiting tumor growth.

Synthetic route of DOX–PLGA conjugate by an ester linkage. Figure 1. Synthetic route of DOX–PLGA conjugate by an ester linkage.

  • As the carrier for gene delivery: Nano dispersion prepared from biodegradable polymer materials have many advantages for gene delivery, such as stability, non-toxicity, non-antigenicity, biocompatibility, controlled-release (which can prolong the time of gene expression) and gene protection. For example, deacetylated chitosan-DNA nano dispersion can prevent DNA from being degraded by nuclease and help DNA transfect cells.
  • As the carrier of anti-infective drugs: When microorganisms infect the body, it can cause an inflammatory reaction, and the permeability of cells in the inflammatory site is in a state of hyperactivity. On the one hand, nano-carriers can change the pharmacokinetic properties of drugs in vivo, prolong the action time of drugs in vivo, and increase the chance of drugs entering inflammatory sites, on the other hand, they can obviously target (RES) in the reticuloendothelial system. And the process of nano-carriers entering cells may be similar to the pathway of microbial infection, so nano-carriers can increase the accumulation of drugs in the infected site, which is conducive to the efficacy of antimicrobial drugs.
  • As the carrier of ophthalmic drugs: Nano-carriers have certain adhesion on the surface, which can prolong their retention time in the eyes and reduce the removal of drugs by tears. Moreover, most of the materials for the preparation of nano-carriers are lipophilic polymer compounds, which can easily pass through the cornea and increase the drug concentration in aqueous humor and corneal tissue, which is beneficial to the treatment of eye diseases.
  • As the carrier of peptide and protein drugs: Nanocarriers can be used as carriers for peptide and protein drugs because they can greatly improve the absorption of drugs in the gastrointestinal tract.


The preparation of the nano-dispersion system includes physical dispersion method (such as ultrasonic dispersion method, mechanical dispersion method, high energy treatment method, etc.) and chemical reaction method (such as dispersant dispersion method, surface chemical modification method) and so on.

Preparation of silica nano-dispersion by surface chemical modification method.Figure 2. Preparation of silica nano-dispersion by surface chemical modification method.


  1. Hyuk SangYoo.(2000) “Invitroandinvivoanti-tumor activities of nanoparticles based on doxorubicin-PLGA conjugates.” J. Controlled Release, 68(3): 419-431.
  2. Lan Ma, Pingya Luo. (2019) “Ultra-Stable Silica Nanoparticles as Nano-Plugging Additive for Shale Exploitation in Harsh Environments.” Nanomaterials. 9(12), 1683