Recent Progress of Photothermal Therapy Based on Conjugated Nanomaterials in Combating Microbial Infections

Abstract

Photothermal therapy has the advantages of non-invasiveness, low toxicity, simple operation, a broad spectrum of antibacterial ability, and non-proneness to developing drug resistance, which provide it with irreplaceable superiority in fighting against microbial infection. The effect of photothermal therapy is closely related to the choice of photothermal agent. Conjugated nanomaterials are potential candidates for photothermal agents because of their easy modification, excellent photothermal conversion efficiency, good photostability, and biodegradability. In this paper, the application of photothermal agents based on conjugated nanomaterials in photothermal antimicrobial treatment is reviewed, including conjugated small molecules, conjugated oligomers, conjugated polymers, and pseudo-conjugated polymers. At the same time, the application of conjugated nanomaterials in the combination of photothermal therapy (PTT) and photodynamic therapy (PDT) is briefly introduced. Finally, the research status, limitations, and prospects of photothermal therapy using conjugated nanomaterials as photothermal agents are discussed.

Keywords: antimicrobial activity; conjugated nanomaterials; photothermal therapy.

Figure 1

Schematic illustration of the preparation and antibacterial application of MCC/CS NPs. (i) Self-assembly of MCC/CS NPs from MCC and chitosan driven by hydrogen bonding and π–π stacking interactions and (ii) as a wound dressing to treat MRSA-infected diabetic mice wounds. Reprinted with permission from ref. [68]. Copyright 2022 Wiley-VCH GmbH.

Figure 2

(A) Fabrication and (B) smart temperature control mechanism of the smart photothermal nanoplatform. (C) Comparison of the therapeutic effects between the smart PTT and conventional PTT. Reprinted with permission from ref. [74]. Copyright 2022 Wiley-VCH GmbH.

Figure 3

The structure of CPDT-T and DSPE-MPEG2000.

Figure 4

The structure of M1, M2, and PLGA-PEG for the preparation of conjugated nanomaterials.

Figure 5

Illustration of (a) the chemical structures of conjugated oligomers, (b) the preparation of NPs, and (c) photothermal antimicrobial therapy based on NPs. Reprinted with permission from ref. [84]. Copyright 2023 Wiley-VCH GmbH.

Figure 6

(a) Self-assembly of PANI nanoparticles (Me-PANI NPs) and their photothermal antibacterial illustration upon NIR laser irradiation. (b) Schematic diagram of the preparation of the NPs@PAM hydrogel and its potential application as a wound dressing. Reprinted with permission from ref. [92]. Copyright 2021 Wiley-VCH GmbH.

Figure 7

Schematic illustration of (A) the preparation of PLNP@PANI-GCS and (B) its persistent imaging-guided photothermal therapy for bacterial infection. Reprinted with permission from ref. [24]. Copyright 2023 Wu, Huang, Huang, Wang, and Wei.

Figure 8

Illustrated preparation of ADPH for bacteria-infected wound healing. Reprinted with permission from ref. [105]. Copyright 2021 Elsevier Ltd.

Figure 9

(a) Illustrated preparation of B@MPDA-Mal. (b) Schematic illustration of the B@MPDA-Mal nanoplatform, which precisely targets antibacterial infection. Reprinted with permission from ref. [107]. Copyright 2023 Wiley-VCH GmbH.

Figure 10

Preparation and photothermal antibacterial activity of the TPP coating. Reprinted with permission from ref. [114]. Copyright 2022 Elsevier B.V.

Figure 11

Illustration of the light-programmable BP-SA nanocomposite hydrogel for promoting wound healing and eliminating bacterial infection under white light and NIR light. Reprinted with permission from ref. [119]. Copyright 2022 Wiley-VCH GmbH.

Figure 12

(A) The synthesis of pPCPs and (B) illustrated design of pPCP-NPs for antibacterial therapy. Reprinted with permission from ref. [28]. Copyright 2022 The Authors.

Figure 13

Schematic illustration of AIE-nanoparticle-mediated PTT and PDT for antimicrobial treatment and wound healing. Reprinted with permission from ref. [128]. Copyright 2022 American Chemical Society.

Figure 14

The synthesis of (a) probe and (b) COF. (c) The illustrated action mechanism of COF@probe. (d) Illustration of the COF@probe nanoplatform for precise imaging-guided chemo/PTT/PDT synergistic sterilization. Reprinted with permission from ref. [129]. Copyright 2021 American Chemical Society.

Figure 15

(A) The synthesis of AIE-PEG₁₀₀₀NPs. (B) The illustrated action mechanism of AIE-Tei@AB NVs. (C) Schematic illustration of the laser-activated “nanobomb” system for trimodal imaging-guided synergistic PTT-PDT-CDT of drug-resistant bacterial infections. Reprinted with permission from ref. [130]. Copyright 2023 American Chemical Society.