Unveiling the Self Assembling Behavior of 5 Fluorouracil and its N,N' Dimethyl Derivative: A Spectroscopic and Microscopic Approach.
Under physiological conditions, 5 fluorouracil (5 FU) an anticancer drug, self assembles into fibrils by strong hydrogen bonding network, whereas its N,N' dimethyl derivative, 5 fluoro 1,3 dimethyluracil (5 FDMU) does not make fibrils due to lack of strong hydrogen bonding motif. In vitro, 5 FU self assembly is sensitive to physicochemical conditions like the pH and ionic strength of the solution, which tune the strength of the noncovalent driving forces. Here we report a surprising finding that the buffer, which is necessary to control the pH and is typically considered to be inert, also significantly influences 5 FU self assembly, which indicates an important role of counterions in the fibril formation. We have also monitored concentration and time dependent fibrillar growth of 5 FU. Again, fibril growth process is probed under dynamic conditions using microfluidic platform. The self assembly of 5 FU compared with its N,N' dimethyl derivative shows lower cytotoxicity to the cultured human erythroleukemic cells (K562 cells) which plausibly states the reason behind the greater effectiveness of 5 FU derivative drugs than 5 FU itself.
Langmuir the ACS journal of surfaces and colloids