Drug release kinetics from biodegradable UV-transparent hollow calcium-phosphate glass fibers

Upcoming medical procedures, such as photodynamic therapy or photochemical tissue bonding, require the local delivery of light and photosensitive dyes in selected deep tissues of the body. To achieve this purpose, it is essential to understand the dye/surface interaction of the materials involved. This work explores the employment of resorbable hollow glass fibers as controlled drug delivery systems and characterizes the release kinetics of four drugs with different chemical behaviors. The designed glass results to be optically transparent, biodegradable and biocompatible. The drugs were chosen in order to understand the interaction mechanism of different chemical species with the glass surface and to assess possible reactions. The results show that all drugs can be delivered, but ionized species tend to be withheld more than neutral molecules, suggesting the occurrence of hydrogen bonding and electrostatic interaction with the hydrophilic glass surface.