Recent Advances of Natural-Polymer-Based Hydrogels for Wound Antibacterial Therapeutics

Abstract

Hydrogels have a three-dimensional network structure and high-water content, are similar in structure to the extracellular matrix, and are often used as wound dressings. Natural polymers have excellent biocompatibility and biodegradability and are commonly utilized to prepare hydrogels. Natural-polymer-based hydrogels can have excellent antibacterial and bioactive properties by loading antibacterial agents or being combined with therapeutics such as phototherapy, which has great advantages in the field of treatment of microbial infections. In the published reviews of hydrogels used in the treatment of infectious wounds, the common classification criteria of hydrogels include function, source of antibacterial properties, type of antibacterial agent, etc. However, there are few reviews on the classification of hydrogels based on raw materials, and the description of natural-polymer-based hydrogels is not comprehensive and detailed. In this paper, based on the principle of material classification, the characteristics of seven types of natural polymers that can be used to prepare hydrogels are discussed, respectively, and the application of natural-polymer-based hydrogels in the treatment of infectious wounds is described in detail. Finally, the research status, limitations, and prospects of natural-polymer-based hydrogels are briefly discussed.

Keywords: antibacterial; hydrogel; natural polymer; wound healing.

Figure 1

Four stages of wound healing: (A) hemostasis, (B) inflammation, (C) proliferation, (D) remodeling. Reprinted with permission from Ref. [11]. Copyright 2018 Elsevier Ltd.

Figure 2

The illustrated preparation process of BP/CS-bFGF hydrogel and the application in promoting diabetic wound healing in mice. Reprinted with permission from Ref. [50]. Copyright 2022 Elsevier Ltd.

Figure 3

Schematic diagram of (A) the hydrogel synthesis mechanism and (B) photothermal/chemo-dynamic synergistic treatment of MRSA-infected wound. Reprinted with permission from Ref. [53]. Copyright 2022 the authors.

Figure 4

Illustration of the hydrogel synthesis mechanism and photothermal/chemodynamic synergistic treatment of MRSA-infected wound. Reprinted with permission from Ref. [54]. Copyright 2023 American Chemical Society.

Figure 5

(A) Illustration of (A) the synthesis of Gel1 (Cyan)/Gel2 (PCN) hydrogel, (B) properties of Gel1 (Cyan)/Gel2 (PCN) hydrogel and (C) the application of Gel1 (Cyan)/Gel2 (PCN) hydrogel in diabetic wound and keratitis healing. Reprinted with permission from Ref. [56]. Copyright 2022 Wiley-VCH GmbH.

Figure 6

Illustrated preparation of (a) CMA molecule and (b) CMA–Ag hydrogel. (c) The mechanism of Ag⁺ releasing from CMA–Ag hydrogel. (d) FT–IR spectra of the agarose and CMA molecule. (e) Morphological characterization of CMA and CMA–Ag hydrogels. (f) Schematic application of CMA–Ag hydrogel in the treatment of infected wounds. Reprinted with permission from Ref. [57]. Copyright 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Figure 7

Schematic diagram of the synthesis of HA-PEGSB-CMP hydrogel and its application in promoting wound healing. (A) The synthesis of HA. (B) The structure of CMP. (C) The synthesis of PEGSB. (D) The preparation of HA-PEGSB-CMP hydrogel. (E) The wound healing application of the hydrogels. Reprinted with permission from Ref. [58]. Copyright 2021 Elsevier B.V.

Figure 8

Schematic preparation of (a) UPy-HDI, (b) BSP-UPy, (c) DAHA and (d) BSP-U/DAHA hydrogels. Reprinted with permission from Ref. [59]. Copyright 2023 Elsevier Ltd.

Figure 9

Schematic preparation and application of RPC/PB hydrogel in the treatment of infected wound. Reprinted with permission from Ref. [60]. Copyright 2022 The Authors.

Figure 10

Illustrated preparation of BC/GG-Cu@ZIF/GOx hydrogel, and its application in antibacterial and hemostasis. Reprinted with permission from Ref. [61]. Copyright 2022 Elsevier Ltd.

Figure 11

Schematic representation of TO/ASP hydrogel. Reprinted with permission from Ref. [62]. Copyright 2022 Elsevier Ltd.