[nanoPost] Colloidal gold nanoparticles for drug delivery

Company USA

Colloidal gold has been safely used for over 70 years to treat rheumatoid arthritis.  In 2000, the company discovered that pegylated colloidal gold nanoparticles bind anti-cancer therapeutics on their surface and carry these drugs safely through the blood stream. 

When injected into the circulation, these particles selectively accumulate in and around solid tumors due to the inherent leakiness of new blood vessels within the tumor.  Based on the Company’s research and chemical understanding of the nanoparticle, in-house scientists are able to bind almost any molecule to the carrier system.

The company also discovered that binding two molecules, for example a chemotherapeutic and a biologic, to the same nanoparticle creates an active tumor-targeted drug delivery vector.  With tumor targeting resulting in increased drug levels in the tumor and reduced drug uptake by healthy organs, the technology improves efficacy and reduces toxicity.

The use of colloidal gold as a human therapeutic dates back to the 1930's when it was shown to temporarily relieve joint inflammation associated with rheumatoid arthritis.Yet the lack of understanding of its mechanism of action has limited its therapeutic potential. The Company believes that the potential for colloidal gold in medicine is very broad, and, through an aggressive patent strategy the Company will seek to capture both its therapeutic and commercial potential.  The Company made a rather surprising observation: animals injected with native cytokine exhibited strong toxicological responses, whereas animals receiving injections of cytokines bound to colloidal gold did not. This singular observation lead us to conclude that colloidal gold may be a universal, clinically safe, commercially sound drug/gene delivery system.

How it works

- Polyethylene glycol (PEG) masks particles from immune recognition preventing uptake by liver and spleen
- Nanoparticles exit circulatory system only at the tumor neovasculature due to leakiness of blood vessels
- Particles too large to exit circulation elsewhere
- TNF targeting molecule on particle’s surface binds to receptors causing rapid absorption of drug in and around tumor

Targeted drug therapy is a promising, fast growing drug delivery application which safely, efficiently and effectively addresses specific diseases while minimizing toxicities. One of the most promising areas in the treatment of cancer has been the development of therapeutic drugs, which attack a tumor by targeting the blood supply to the tumor and/or specifically interacting with or stimulating the immune system. However, the key obstacle has been to effectively deliver the proven therapeutics in a way that minimizes adverse side effects. 

Targeted biodistribution of cancer therapeutics will enable such drugs to have the maximum efficacy while minimizing adverse side effects. The company believes that such site-specific drug delivery for cancer treatment may now be accomplished with the company’s patented delivery system. The core of this platform technology is colloidal gold; a unique compound that has, for over 70 years, been used safely as a therapeutic for rheumatoid arthritis.

Coating nanometer sized colloidal gold particles with the company’s patented technology completely alters the biodistribution of these particles, allowing them to find solid tumors and deliver therapeutic payloads while bypassing normal cells.

This versatile drug delivery platform is able to bring potent anticancer drugs directly to the tumor. 

The company’s patented colloidal gold drug delivery vector may also be used to carry other specific small molecule therapeutics to tumors and localize them in and around the tumor blood vessels. Tumor targeting is achieved by two mechanisms: passive targeting through leaky tumor blood vessels (as discussed below) and active targeting through binding to cell surface receptors in and around the tumor. In addition to delivering protein biologics to tumors, the company plans to use this vector to deliver small molecules, such as derivatives of taxol or other chemotherapeutics as a targeted drug therapy.