The field of nanotechnology holds a great deal of promise in the treatment of cancer.
For instance, in a recent breakthrough, researchers used nanoparticles to spot previously undetectable microtumors, while another study used nanoparticles derived from tea leaves to destroy lung cancer cells.
Nanoparticles are often used to transport drugs and deliver them straight to diseased tissue. These so-called nanocarriers were recently used to successfully destroy a particularly aggressive form of endometrial cancer, and to deliver a drug that genetically "disarms" cancer stem cells.
These drug-filled nanocapsules are about a thousandth of the diameter of a human hair, and they are usually covered with antibodies designed to seek out and attach to tumor cells.
One main advantage of these nanocarriers is that they deliver concentrated drugs with precision, without affecting the rest of the body and dispersing its potential side effects.
Now, researchers at the Mainz University Medical Center and the Max Planck Institute for Polymer Research — both in Mainz, Germany — have engineered an innovative and more effective way of binding the antibodies to the nanocarriers.
Prof. Volker Mailänder, at Mainz University Medical Center, supervised the research together with Prof. Katharina Landfester, from the Max Planck Institute for Polymer Research.
The findings were published in the journal Nature Nanotechnology.
New method twice as effective as older ones
"The standard method of binding antibodies using complex chemical processes can degrade antibodies or even destroy them, or the nanocarrier in the blood can become rapidly covered with proteins," explains Prof. Landfester.
But the new method uses pre-adsorbed antibodies to cover the surface of the nanocapsules. This protects the antibodies and keeps them functional in the delivery process, which stabilizes the nanocapsule and enables it to deliver the drugs more efficiently.
The physical process of adsorption "occurs when a gas or liquid solute accumulates on the surface of a solid or a liquid (adsorbent), forming a film of molecules or atoms (the adsorbate)."
The team achieved this effect by combining antibodies and the nanocarriers in an acidic solution, which, the researchers explain, is better than binding the two in a Ph-neutral solution.
The researchers note that their new method is twice as effective as traditional chemical bonding.
"We conclude," the authors write, "that pre-adsorption is potentially a versatile, efficient, and rapid method of attaching targeting molecules to the surface of nanocarriers."
The video below gives a visual representation of the findings:
"Up to now, we have always had to use elaborate chemical methods to bind these antibodies to nanocapsules [...] We have now been able to show that all that you need to do is to combine antibodies and nanocapsules together in an acidified solution."
Prof. Volker Mailänder
The researchers are hopeful that the new method will improve nanotechnology-based therapies overall, enabling nanocapsules to target diseased tissue while preserving healthy tissue.