Abstract
The increasing need for biocompatible materials as supports to immobilize photosensitizer molecules for photodynamic therapy (PDT), led us to investigate the use of chitin as a support for 4,4',4″,4‴-(porphine-5,10,15,20-tetrayl)tetrakis(benzoic acid) (mTCPP) for singlet oxygen production. Chitin was first extracted from shrimp shells using the ionic liquid 1-ethyl-3-methyl-imidazolium acetate ([C2mim][OAc]), coagulated as a floc into water, and then deacetylated to varying degrees of deacetylation using 4 M NaOH. The deacetylated chitin (DA-chitin) was dissolved in [C2mim][OAc] and mTCPP was covalently attached by reaction between the amino groups of DA-chitin and the carboxyl groups of mTCPP using N-(3-(dimethylamino)propyl)- N'-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) as activators. The resulting composite polymers were cast as a film and coagulated with water to remove IL and excess reagents, resulting in homogeneous DA-chitin/mTCPP films. Attempts to prepare films by coagulation from a solution containing chitin and mTCPP to physically entrap the porphyrin, resulted in aggregation of mTCPP in the film. The DA-chitin/mTCPP films had strong optical absorbance and their absorbance intensity could b...Continue Reading