One concern with anti-cancer medications is with being able to accurately direct drugs to sites where tumors are present, so that that the medication targets the tumor rather than affecting health cells. This degree of precision is being worked on by several research institutions.
In a new area, researchers from the Division of Applied Sciences and Technology at NIBIB have developed nanocarriers. These are very tiny particles packed with anti-cancer drugs. The aim of the carriers is to avoid releasing any of the potent anti-cancer drug until the carrier has reached the site of the tumor; this is to avoid the drug affecting too may health cells.
While the protective part of this seems to work, the precise targeting of the carriers still remains an issue. In addition, the physical pressure that many tumors generate acts as barrier to such carriers and acts as a blockage. To be effective an anti-cancer medication needs to reach the tumor’s hypoxic zones, which are areas of low oxygen where tumor cells divide.
Explaining this further, lead researcher Dr. Sylvain Martel told Controlled Environments magazine: “Only a very small proportion of drugs reach the hypoxic zones, which are believed to be the source of metastasis. Therefore, targeting the low-oxygen regions will most likely decrease the rate of metastasis while maximizing the effect of a therapy.”
In order to improve targeting, the researchers have been experimenting with robotic nanocarriers that use a magnetic bacterium called Magnetococcus marinus. These organisms exist in low oxygen environments. What is special about them is their navigation system, where they have a sort of built-in compass that causes the bacteria to swim in a north direction when in the Northern Hemisphere. The organism also has sensors that keeps it in areas that have a low oxygen supply.
Studies using carriers based on the bacteria (with analogous magnetic beads) have been undertaken using mice with tumors, where the carriers were injected into the bloodstream. The movement of the carriers was tracked and improved accuracy detected. Further work has been performed using the bacteria in the carriers; here, nanorobotic agents were composed of more than 100 million flagellated bacteria
The next phase of the research is to determine the effects of the drug-loaded bacterial cells on reducing tumor size.
The research findings have been reported to the journal Nature Nanotechnology. The research is titled “Magneto-aerotactic bacteria deliver drug-containing nanoliposomes to tumour hypoxic regions.”
In related news, Digital Journal has previously reported on studies have taken place in Canada whereby magnetic bacteria are used to power nano-devices, to help ferry anti-cancer medicines to sites of tumors. Such devices offer faster and more precise drug delivery.
