Drug delivery in mesostructured SiO2 films doped with Rhodamine B using femtosecond infrared laser pulses

Controlled drug delivery is an important goal for medical applications. There are at least three distinctive elements in these systems, the reservoir, one active element and the stimulus which allows the active element releases the drug. In the present work we prepared mesostructured SiO2 films by sol-gel route, doped with the azochromophore DR1. Mesostructure has nanotubes with hexagonal symmetry. DR1 molecule performs a configuration trans to cis change when absorbing green light, and then go back to its trans state. In that way DR1 can hit surrounding molecules and push them away the nanotubes. We show our results of Rhodamine B delivery in our system by using green laser light illumination. But green light is absorbed in a fraction of millimeter by the animals and human skin, therefore it cannot be used in medical cases. But infrared light easily penetrates the skin and travels some centimeters on tissues. We explain why to use femtosecond infrared lasers and we will show our obtained results of Rhodamine B released with these lasers.