Cyanobacteria-based self-oxygenated photodynamic therapy for anaerobic infection treatment and tissue repair

Bailiang Wang; Liyang Zhou; Yishun Guo; Hanwen Guo; Yiming Zhong; Xiaomin Huang; Yifan Ge; Qingying Wang; Xiaoying Chu; Yingying Jin; Kaiyue Lan; Mei Yang; Jia Qu

doi:10.1016/j.bioactmat.2021.10.032

Cyanobacteria-based self-oxygenated photodynamic therapy for anaerobic infection treatment and tissue repair

Bioact Mater. 2021 Oct 30:12:314-326. doi: 10.1016/j.bioactmat.2021.10.032. eCollection 2022 Jun.

Authors

Bailiang Wang^{1

2}, Liyang Zhou^{1

2}, Yishun Guo^{1

2}, Hanwen Guo^{1

2}, Yiming Zhong^{1

2}, Xiaomin Huang^{1

2}, Yifan Ge^{1

2}, Qingying Wang^{1

2}, Xiaoying Chu^{1

2}, Yingying Jin^{1

2}, Kaiyue Lan^{1

2}, Mei Yang^{1

2}, Jia Qu^{1

2}

Affiliations

¹ School of Ophthalmology and Optometry, Eye Hospital, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, 325000, PR China.
² Research Group of Advanced Ophthalmology Bionic Interface Materials, Oujiang Laboratory, Wenzhou, 325000, PR China.

Abstract

Photodynamic therapy (PDT) is an important technique to deal with drug-resistant bacterial infections in the post-antibiotic era. However, the hypoxic environment in intractable infections such as refractory keratitis and periodontitis, makes PDT more difficult. In this work, spontaneous oxygen-producing cyanobacteria were used as the carrier of photosensitizer (Ce6), and ultrasmall Cu_5.4O nanoparticles (Cu_5.4O USNPs) with catalase activity for infection and inflammation elimination and rapid tissue repair (CeCycn-Cu_5.4O). The loading of Ce6 and Cu_5.4O USNPs onto cyanobacteria surface were confirmed by transmission electron microscopy, nano particle size analyzer, scanning electron microscopy. In vitro sterilization and biofilm removal experiments demonstrated that the restriction of hypoxic environment to PDT was significantly alleviated due to the oxygen production of cyanobacteria. Under laser irradiation, the close transfer of energy photons to oxygen produced by cyanobacteria reduced more than 90% of Ce6 dosages (660 nm, 200 mW/cm², 2 min). It is worth mentioning that both rapid sterilization through PDT and long-term oxidized free radicals elimination were achieved by adjusting the ratio of Ce6 and Cu_5.4O USNPs. Both periodontitis and refractory keratitis animal models proved the excellent self-oxygenation enhanced antibacterial property and promotion of tissue repair.

Keywords: Anaerobic infection; Periodontitis; Photodynamic therapy; Refractory keratitis; Self-oxygenated.