In this study, homogeneous hydrogels based on chitosan containing ninhydrin derivatives, including Ruhemann’s purple (RP) and its Zn(II) Schiff base chelate of indane-l,3-dione-2- imine-N-acetic acid (Zn(II)IDIA), as photosensitizers have been synthesized with the potential of photodynamic therapy (PDT) applications. Ninhydrin is a valuable organic compound that exhibits bacteriostatic, virucidal, and anti-diabetogenic properties. This study describes how the use of ninhydrin is a viable option for the investigation of in vitro PDT activities. The hydrogels were prepared through chemical cross-linking using glutaraldehyde and loaded with water-soluble photosensitizers. According to the results, the hydrogels demonstrated a threedimensional (3D) porous morphology, remarkable singlet oxygen generation, antibacterial activity, and good mechanical strength. The results of the cell viability assay illustrated their excellent biocompatibility and safety. All the information in this study supports the capability of the hydrogels containing RP and Zn(II)IDIA for PDT treatment.
