1. Academic Validation
  2. An efficient antimicrobial depot for infectious site-targeted chemo-photothermal therapy

An efficient antimicrobial depot for infectious site-targeted chemo-photothermal therapy

  • J Nanobiotechnology. 2018 Mar 16;16(1):23. doi: 10.1186/s12951-018-0348-z.
Menglong Liu 1 Danfeng He 1 Tao Yang 1 Wei Liu 1 Li Mao 2 Yang Zhu 3 Jun Wu 4 5 Gaoxing Luo 6 Jun Deng 7
Affiliations

Affiliations

  • 1 Institute of Burn Research, Southwest Hospital, State Key Lab of Trauma, Burn and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China.
  • 2 Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, (Army Medical University), Chongqing, 400038, People's Republic of China.
  • 3 Departments of Bioengineering and Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA.
  • 4 Institute of Burn Research, Southwest Hospital, State Key Lab of Trauma, Burn and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China. editorinchief@burninchina.com.
  • 5 Department of Burns, The First Affiliated Hospital, SunYat-Sen University, Guangzhou, 510080, China. editorinchief@burninchina.com.
  • 6 Institute of Burn Research, Southwest Hospital, State Key Lab of Trauma, Burn and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China. logxw@yahoo.com.
  • 7 Institute of Burn Research, Southwest Hospital, State Key Lab of Trauma, Burn and Combined Injury, Third Military Medical University (Army Medical University), Chongqing, 400038, China. djun.123@163.com.
Abstract

Background: Silver and photothermal therapy (PTT) have been widely used for eradicating the drug-resistant bacteria. However, the risks of excess of silver for humans and the low efficiency of PTT still limit their in vivo therapeutic application. Integration of two distinctive bactericides into one entity is a promising platform to improve the efficiency of antimicrobial agents.

Results: In this study, a chemo-photothermal therapeutic platform based on polydopamine (PDA)-coated gold nanorods (GNRs) was developed. The PDA coating acquired high Ag+ ions loading efficiency and Cy5-SE fluorescent agent labeled glycol chitosan (GCS) conjugation (Ag+-GCS-PDA@GNRs). This platform became positively charged in the low pH environment of the abscess, allowing their accumulation in local Infection site as revealed by thermal/florescence imaging. The loaded Ag+ ions was released in a pH-sensitive manner, resulting in selective Ag+ ions delivery to the abscess environment (pH ~ 6.3). More importantly, the ultralow dose of Ag+ ions could effectively damage the Bacterial membrane, causing the permeability increase and the heat resistance reduction of the cell membrane, leading to the large improvement on bactericidal efficiency of PTT. On the other hand, the hyperthermia could trigger more Ag+ ions release, resulting in further improvement on bactericidal efficiency of chemotherapy. Combinational chemo-hyperthermia therapy of Ag+-GCS-PDA@GNRs could thoroughly ablate abscess and accelerate wound healing via a synergistic Antibacterial effect.

Conclusions: Our studies demonstrate that Ag+-GCS-PDA@GNRs is a robust and practical platform for use in chemo-thermal focal Infection therapy with outstanding synergistic bacteria ablating.

Keywords

Bacterium-specific targeting; Charge conversion; Combinational chemo-hyperthermia therapy; Drug-resistant bacteria; pH-sensitive release.

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