Shooting at the tumor with separable warheads
Nanoparticles – separate to dominate
ChemPort.Ru based on RSC materials: Nanoparticle divides to conquerThe researchers obtained nanoparticles that split into smaller objects upon contact with their target, which allows them to penetrate deeper into the tumor tissue, providing more effective treatment.
Although great efforts are currently being made to create nanoparticles that deliver drugs for the treatment of malignant tumors, in practice such delivery systems, as a rule, are practically not highly effective compared to methods of treating tumors "without nano". This is due to the fact that the size of most nanoparticles does not allow them to penetrate deep into the dense tissue of tumors.
The joint work of researchers from the Massachusetts Institute of Technology and Harvard Medical School suggests a possible increase in the effectiveness of tumor treatment using nanoparticles, using a system that, when passing a solid barrier, can fragment like fruit jelly.
One of the authors of the study, Dai Fukumura from Harvard Medical School, explains that the pore size in the membrane of tumor cells is larger than the pore size in the membrane of healthy cells. Thus, according to the majority of researchers, the use of nanoparticles with a size of 100 nm will make it possible to achieve selective infiltration of drug carriers into the tumor cell, increasing the effectiveness of the treatment of malignant tumors.
According to Fukumura, problems in the implementation of "nano-treatment" of cancer arise when particles with a size of 100 nm reach the tumor tissue, their size turns out to be too large to pass through the dense matrix tissues of the tumor itself. Collaboration with MIT allowed medical researchers to develop a new approach to the creation of nanoparticles - gel nanoobjects that can solve the problem of getting into a tumor.
The new nanoparticles are balls of gelatin with a radius of 100 nm, inside these balls there are solid nanoparticles, the size of which is only 10 nm. When the gelatin nanoparticles reach the tumor, the enzymes secreted by the tumor break down the gelatin, resulting in the release of the contents of the "gelatin container", which already enters the tumor. In vitro studies have shown that the new system is better infiltrated into the tumor than traditional nanoparticles with a large and constant size.
A drawing from an article by Cliff Wong et al.
Multistage nanoparticle delivery system for deep penetration into tumor tissue
(PNAS, January 18, 2011)
Paul Borm, a specialist in the use of nanoparticles in medicine, expresses some concern that the system working in vitro may not work in vivo, especially if drugs are grafted onto smaller nanoparticles.
However, Fukumura still talks about his work as a fundamental demonstration of the possibility aimed at finding out the possibility of using "nanoparticles with fillings". In the future, doctors from Harvard and specialists from MIT plan to optimize the transport of small nanoparticles through the tumor in order to select the most effective size, charge and surface properties.
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20.01.2011