A Simple Phthalocyanine-Peptide Conjugate as Targeting Photosensitizer and Its Broad Applications in Health

Review A Simple Phthalocyanine-Peptide Conjugate as Targeting Photosensitizer and Its Broad Applications in Health Zheng Chen 1, Jincan Chen 2, Dafeng Liu 3, Jingyi Chen 1, Linlin Li 1, Dan Chen 1, Naisheng Chen 1, Jinling Huang 1, Zhuo Chen 2, Peng Xu 4, Longguang Jiang 1, Cai Yuan 4,*, Yunbin Jiang 5,* and Mingdong Huang 1,* 1 National & Local Joint Biomedical Engineering Research Center on Photodynamic Technologies, College of Chemistry, Fuzhou University, Fuzhou 350108, China 2 State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fujian College, University of Chinese Academy of Sciences, Fuzhou 350002, China 3 College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China 4 College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China 5 School of Biological Science and Biotechnology, Minnan Normal University, Zhangzhou 363000, China * Correspondence: cyuan@fzu.edu.cn (C.Y.); jyb1972@mnnu.edu.cn (Y.J.); HMD_lab@fzu.edu.cn (M.H.) Received: 28 August 2024; Revised: 9 October 2024; Accepted: 17 October 2024; Published: 25 October 2024 Abstract: Photodynamic therapy is a novel clinical treatment for malignant tumors, and has recently been extended to anti-bacteria and anti-virus applications. Phthalocyanine photosensitizers possess good photosensitization properties, but their high hydrophobicity and lack of targeting capabilities limit their application. By conjugating a pentalysine peptidyl moiety to hydrophobic phthalocyanine, a novel photosensitizer (ZnPc(Lys)5) was synthesized. This review systematically summarizes the design, development, safety and characterization of ZnPc(Lys)5, and describes its applications and mechanisms in anti-tumor, anti-bacterial and anti-viral areas, as well as exploring its prospects for applications beyond photodynamic therapy. This review demonstrates that the peptide conjugation is an effective strategy for enhancing water solubility and broadens the applications of phthalocyanine-type photosensitizers. Furthermore, the importance of dynamic balance between the monomeric and aggregate conformations of phthalocyanine underlying its photodynamic effect is highlighted, providing a fresh perspective for the design and application of photosensitizers.