Design of a light-responsive porphyrin/polysaccharide hybrid film for smart release of hydrocortisone

Responsive materials are the utmost systems to deliver drugs in a controllable and efficient manner. In this sense, the association between photo-responsive molecules and polysaccharides can result in materials able to deliver drugs under demand using light as external stimuli. Herein, a light-responsive hybrid film of Ca2+-cross-linked alginate (ALG) and 3-PtTPyP, a metalloporphyrin, was prepared and tested as a delivery system. Fully characterization revealed that the prepared film had a light-induced weight loss behavior caused by the degradation of the alginate matrix by reactive oxygen species (ROS) generated by the photo-excited 3-PtTPyP. This light-responsive property was further exploited to control the release of hydrocortisone (HC) from the hybrid film. As observed, the HC release rate is faster when light irradiates the film, which also changes the release mechanism. The finds reported indicated that the prepared hybrid film is a potential smart delivery system for the HC release, which may benefit the use of this drug to treat skin diseases. Furthermore, the photodynamic action of the 3-PtTPyP@ALG films against mycobacteria strains was demonstrated, highlighting the ability of this original material to act simultaneously in antibacterial photodynamic therapy.