Effects of Photodynamic Therapy Using 5 -Aminolevulinic Acid (ALA) Loaded Acrylic Nanoparticles (ANPs) on HaCaT Cells

Kang Ge,1,2 Yilu Zhao,2,3 Xiao Liu,4 Ruzhi Zhang5 1Jiaxing Key Discipline of Medicine --Dermatology and Venereology, The Affiliated Hospital of Jiaxing University, The First Hospital of Jiaxing, Jiaxing, Zhejiang, People’s Republic of China; 2Department of Dermatology, The First Affiliated Hospital of Bengbu Medical University, Bengbu, Anhui, People’s Republic of China; 3Department of Dermatology, The Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu, People’s Republic of China; 4School of Materials Science and Engineering, Changzhou University, Changzhou, Jiangsu, People’s Republic of China; 5Department of Dermatology and STD, The Second Affiliated Hospital of Wannan Medical College, Wuhu, Anhui, People’s Republic of ChinaCorrespondence: Ruzhi Zhang, Department of Dermatology and STD, The Second Affiliated Hospital of Wannan Medical College, Wuhu, Anhui, 241001, People’s Republic of China, Tel +8618761161826, Email zhangruzhi628@163.comObjective: ALA-PDT (5-aminolevulinic acid photodynamic therapy) is a central modality in the treatment of skin diseases. Increasing the bioavailability of ALA remains a critical issue. With this in mind, our study explores a novel route of ALA delivery by loading acrylic nanoparticles (ANPs).Methods: ALA-ANPs were synthesized by emulsion polymerisation and characterised by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). The effects of ALA-ANPs on HaCaT cell line were evaluated, including characteristics, morphological changes, protoporphyrin IX (PpIX) fluorescence kinetics, reactive oxygen species (ROS) levels, mitochondrial membrane potential and ki67 expression in these cells.Results: The ANPs had uniform sizes, smooth surfaces and excellent light transmittance, with diameters of 150– 200 nm. In contrast, the ALA - ANPs had uneven surfaces and poor light transmittance, with diameters of 220– 250 nm. During 12 hours of co-incubatio