Russian scientists at the Lomonosov Moscow State University, using computer models, report that it should be possible in the coming years to create double-shelled nano-capsules that could be used for targeted drug delivery. And they could be relatively inexpensive to produce, too.
Writing in Scientific Reports, Igor Potemkin, chair of Polymer and Crystal Physics at the university, said that although gel nano-capsules have been undervalued as carrier systems, by using computer models of a double-walled carrier--like an egg within and egg--that are each made up of membranes of different chemical structures they were able to come up with a solution.
The problem had been that single-walled capsules tended to stick together and lost colloidal stability when trying to “upload” a drug, rendering them ineffective.
However, with the two-walled nano carrier, the outer and more porous shell protects the inner shell that can open and close depending on the temperature due to variable interactions between its monomeric units.
When the nano-capsules are filled at a certain temperature the pores of both shells are open, allowing the drug molecules be absorbed. When the temperature is changed, the pores of the inner shell close, locking the drug in the cavity and making it ready for delivery. The pores then open to release the guest molecules in the correct place point--like cancer cells--where the temperature allows.
“There are still many questions,” Potemkin said. “We have ‘caught’ a structure in which a cavity does not collapse as the pores are closed. Now we need to understand why it happens, how does the density of the layers crosslink effect... what is the minimum amount of crosslink that does not lead to collapse of the cavity, and so on.”
Potemkin that they are at least another four years from answering those and many other questions.