Evaluation of polyvinylpyrrolidone and block copolymer micelle encapsulation of serine chlorin e6 and chlorin e4 on their reactivity towards albumin and transferrin and their cell uptake

Encapsulation of porphyrinic photosensitizers (PSs) into polymeric carriers plays an important role in enhancing their efficiency as drugs in photodynamic therapy (PDT). Porphyrin aggregation and low solubility as well as the preservation of the advantageous photophysical properties pose a challenge on the design of efficient PS-carrier systems. Block copolymer micelles (BCMs) and polyvinylpyrrolidone (PVP) are promising drug delivery vehicles for physical entrapment of PSs. BCMs exhibit enhanced dynamics as compared to the less flexible PVP network. In the current work the question is addressed how these different dynamics affect PS encapsulation, release from the carrier, reaction with serum proteins, and cellular uptake.