Cationic porphyrin–xylan conjugate hydrogels for photodynamic antimicrobial chemotherapy

Abstract

Bio‐based hydrogels are attractive materials for many biomedical purposes such as drug delivery or wound healing. A light‐triggered antibacterial activity can be conferred to hydrogels after their conjugation to appropriate photosensitizers (PS). In this study, we have synthesized and characterized hydrogels consisting of cationic porphyrin–xylan conjugates. A cationic porphyrin was covalently attached to xylan by an esterification reaction. Different porphyrin‐xylan derivatives were obtained with degrees of substitution ranging from 0.003 to 0.053. Then, the derivatives were cross‐linked after reaction with diethylenetriaminepentaacetic (DTPA) dianhydride to obtain the corresponding hydrogels. The study of the morphology and rheology of the hydrogels showed that the materials obtained present interconnected porous structures, good mechanical integrities as well as high swelling ratios. Antimicrobial activity of cationic porphyrin–xylan conjugate hydrogels was tested under white light irradiation against Staphylococcus aureus and Pseudomonas aeruginosa. All of the tested hydrogels showed photo‐bactericidal activity against the two tested strains.

Photo-activated Efficacy Against HIV-1, Multiple Microbes and Biofilms by Zinc-complexes of Combinations of Cationic Ammoniumphenyl and Methylpyridinium-Porphyrins

“…The 1 HNMR spectral data of P 3 A conforms to the published values. 41,45,51 For P 3 Am, c-P 2 Am 2 and PAm 3 , the 1 HNMR spectral plots (Figure S8-S10) and tabulated spectral data (Table S1) agree with the published values 42,43 and con rm the identity of the compounds. The HRMS (ESI) data of the acetamidophenyl and aminophenyl porphyrins further indicate their purity; the mass error in each case was less than 5 ppm (Figure S20-S25).…”

Xylan–Porphyrin Hydrogels as Light-Triggered Gram-Positive Antibacterial Agents

“…The antibacterial activity of xyl-TCPP-3, TCPP-free, and xylan-hydrogel alone were assessed against two Gram-positive bacteria, S. aureus and B. Cereus, in the absence of irradiation and under light activation [21][22][23]. TCPP-free and xylan-hydrogel alone are used as the control.…”

“…The incorporation of PSs into a hydrogel can be carried out either by simple non-covalent encapsulation or by covalent bonding; the latter method avoids leakage of PS from the hydrogel and thus prevents a potential loss of activity [16][17][18][19][20]. In our previous work, we presented two methods for the synthesis of transparent xylan-based hydrogels containing covalently or non-covalently attached cationic porphyrins using diethylenetriaminepentaacetic (DTPA) dianhydride as a cross-linking agent [21,22].…”