CD Bioparticles is a leading manufacturer and supplier of various drug delivery products, including metallic nanoparticles for R&D and commercialization in a variety of application areas. Metal nanoparticles are emerging as a new class of functional nanomaterials in the area of biological sensing, labelling, imaging and therapy due to their unique physical and chemical properties.
Introduction to Metallic Nanoparticles
In general, metal nanoparticles used in the field of biotechnology range in particle size between 10 and 500 nm, seldom exceeding 700 nm, because the nanosize will allow various communications with biomolecules on the cell surfaces and within the cells in way that can be decoded and designated to various biochemical and physiochemical properties of these cells. Recently, various kinds of metal nanocages (NCs) including gold (Au), silver (Ag) and copper (Cu) NCs have been widely exploited for applications in the area of biological sensing, labelling, imaging and therapy. In order to utilize nanoparticles for their application, we need to select and design nanoparticulate systems that are stable, biocompatible, and selectively directed to specific sites in the body after systemic administration. That is why more specific targeting systems are designed to recognize the targeted cells such as cancer cell by modifying with various chemical functional groups which allow them to be conjugated with antibodies, ligands, and drugs of interest. In general, the surface functionalization of these metal NCs can be accomplished through two different ways: functionalization during the synthesis and post-synthesis functionalization.
Functionalization During the Synthesis
Some of the functional groups could be conjugated to the surface of nanoparticles during the synthesis. The robust covalent bond between gold and thiols forms gold–sulfur interface which allows the exploitation of thiols as protecting ligands for the synthesis and functionalization of metal NPs. The functionalization of biomolecules on metal NCs is also very important to provide biocompatible platforms for biomedical applications with minimal toxicity. Various biomolecules such as nucleic acids, proteins, peptides, dendrimers and polymers that have been used to conjugate with various metal nanoparticles based on different biomedical need.
Figure 1. (a) Schematic illustration of the NaOH-mediated NaBH4-reduction method for the synthesis of thiolated Au NCs. (Copyright (2014) Wiley-VCH.) (b) Schematic illustration and the intriguing optical absorption spectra of Au25 NCs protected by negatively charged thiolate ligands collocating with positively charged thiolate ligands. (Copyright (2016) Royal Society of Chemistry)
Post-synthesis functionalization means that conjugation will be conducted to the already formed mental nanoparticles agents to broaden their applications in biomedical science. During the process, a delicate selection of good stabilizers with desirable terminal functionalities, such as primary amine, carboxylic acid, and alcohol, will be used to prevent the metal NCs from aggregation. There is a wide spectrum of conjugation reagents including small molecules (e.g., folic acid) to macromolecules (e.g., proteins and DNA) and genes. The chemistry for conjugation process is based on the terminal functional groups of the metal NCs and the functional groups of the desired biomolecules. Post-synthesis ligand exchange is another efficient route for surface functionalization of metal NCs in solution by partially or completely exchanged the original ligand with the new ones. Ligand exchange reactions are known to be vital for the surface modification of quantum dots (QDs) and metal nanocrystals.
Our Featured Services
CD Bioparticles is specialized in the development of drug delivery systems and customizing nanoparticles for drug delivery utilizing our core technologies. With our high-quality products and services, the efficacy of your drug delivery can be tremendously improved.
We offer well-designed metallic nanoparticles with various functional groups. Clients may select the material type, particle size, size distribution, and/or surface functional groups such as carboxyl. And we also provide custom services for designing and synthesizing metallic nanoparticles with special required drugs loading, together with its analysis and characterization before and after drug encapsulation.
Quotations and Ordering
1. Vicky V. Mody, et al. Introduction to metallic nanoparticles. J Pharm Bioallied Sci. 2010,2(4): 282–289.
2. Xiaorong Song, et al. Functionalization of Metal Nanoclusters for Biomedical Applications. The Analyst, 2016, 141(11).