title: Dual antibacterial activities of a chitosan-modified upconversion photodynamic therapy system against drug-resistant bacteria in deep tissue.
abstract: Photodynamic therapy (PDT) has recently been proposed as an innovative approach to combat multi-drug resistant (MDR) bacteria. To improve the penetration depth of current PDT, a core-shell upconversion nanoparticle (UCNP) based PDT system, composed of a cationic N-octyl chitosan (OC) coated UCNP loaded with the photosensitizer zinc phthalocyanine (OC-UCNP-ZnPc), was constructed to enhance the antibacterial efficacy against MDR bacteria in deep tissue. The core-shell UCNPs displayed a higher upconversion fluorescence efficiency compared to the inner UCNP core. Dual antibacterial activities induced by chitosan and PDT-induced ROS were demonstrated, independent of the bacterial species. In particular, these nanoconstructs exhibited excellent antibacterial effects on the MDR bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and β-lactamase-producing Escherichia coli. In vivo antibacterial therapy for murine MRSA-infected abscesses in the deep tissue (1 cm) strongly confirmed the outstanding anti-MRSA efficacy of OC-UCNP-ZnPc. Our results indicated that the OC-UCNP-ZnPc based PDT system triggered by deep-penetrating NIR light has a prominent antibacterial effect on MDR bacteria, which could be a promising strategy for deep-tissue infections.
authors.affiliation: Department of Biomedical Engineering, China Pharmaceutical University, No. 24 Tongjiaxiang, Nanjing, Jiangsu 210009, China. guyueqing@hotmail.com.
authors.forename: Siwen
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Biomedical Engineering, China Pharmaceutical University, No. 24 Tongjiaxiang, Nanjing, Jiangsu 210009, China. guyueqing@hotmail.com and School of Life Science, Northeast Normal University, No. 5268 Renmin Street, Changchun, Jilin 130024, China.
authors.forename: Sisi
authors.initials: S
authors.lastname: Cui
authors.affiliation: Department of Biomedical Engineering, China Pharmaceutical University, No. 24 Tongjiaxiang, Nanjing, Jiangsu 210009, China. guyueqing@hotmail.com.
authors.forename: Deyan
authors.initials: D
authors.lastname: Yin
authors.affiliation: Department of Biomedical Engineering, China Pharmaceutical University, No. 24 Tongjiaxiang, Nanjing, Jiangsu 210009, China. guyueqing@hotmail.com.
authors.forename: Qiuyun
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: Department of Biomedical Engineering, China Pharmaceutical University, No. 24 Tongjiaxiang, Nanjing, Jiangsu 210009, China. guyueqing@hotmail.com.
authors.forename: Yuxiang
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Biomedical Engineering, School of Automation, Nanjing University of Aeronautics and Astronautics, 29th JiangJun Street, Nanjing 211106, Jiangsu Province, China.
authors.forename: Zhiyu
authors.initials: Z
authors.lastname: Qian
authors.affiliation: Department of Biomedical Engineering, China Pharmaceutical University, No. 24 Tongjiaxiang, Nanjing, Jiangsu 210009, China. guyueqing@hotmail.com.
authors.forename: Yueqing
authors.identifier: http://orcid.org/0000-0003-1315-4618
authors.initials: Y
authors.lastname: Gu
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D048271:Chitosan; D004337:Drug Carriers; D005260:Female; D007211:Indoles / Q000008:administration & dosage; D054833:Isoindoles; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects*; D051379:Mice; D008813:Mice, Inbred ICR; D053758:Nanoparticles; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000008:administration & dosage*; D013203:Staphylococcal Infections / Q000188:drug therapy*
chemical_list: D000900:Anti-Bacterial Agents; D004337:Drug Carriers; D007211:Indoles; D054833:Isoindoles; D017319:Photosensitizing Agents; D048271:Chitosan; C013647:phthalocyanine