Fabrication of chitosan hydrogels having phthalocyanine-colistin Conjugate as an antibacterial agent in photodynamic therapy

The preparation of a novel antibacterial system is a crucial therapeutic prerequisite to treat wounds affected by multidrug-resistant Gram-negative bacteria.1 Antibacterial photodynamic therapy (APDT) is a hopeful therapy for bacterial infection.2 However, the usage of most photosensitizers is limited by their low water solubility and their inadequacy in disruption of the outer membrane of Gram-negative bacteria.3 In this context, zinc phthalocyanine-colistin (ZnPc-Col) conjugate as a new photosensitizer was prepared in the hope of modifying interaction of phthalocyanine with the surface of Gram-negative bacteria. Solving the problem of the poor solubility of phthalocyanine, was gained by the incorporation of ZnPc-Col into chitosan hydrogel. The weight percentages of ZnPc-Col and glutaraldehyde had significant influences in determining the hydrogel microstructure. Different spectroscopic methods, SEM, and rheological measurements were applied to investigate the properties of ZnPc-Col and fabricated hydrogels. The photosensitizing activity of the hydrogels was assessed by application of 1,3-diphenylisobenzofuran as a singlet oxygen chemical quencher. Hydrogels bearing zinc phthalocyanine-colistin adduct showed an enhanced APDT efficiency compared to hydrogels containing just zinc phthalocyanine component. This improvement has been seen against P. aeruginosa

کلیدواژه ها:

Hydrogel ، Phthalocyanine ، Chitosan ، Colistin ، Photodynamic Therapy