Smart 3D Printed Hydrogel Skin Wound Bandages: A Review

Abstract

Wounds are a major health concern affecting the lives of millions of people. Some wounds may pass a threshold diameter to become unrecoverable by themselves. These wounds become chronic and may even lead to mortality. Recently, 3D printing technology, in association with biocompatible hydrogels, has emerged as a promising platform for developing smart wound dressings, overcoming several challenges. 3D printed wound dressings can be loaded with a variety of items, such as antibiotics, antibacterial nanoparticles, and other drugs that can accelerate wound healing rate. 3D printing is computerized, allowing each level of the printed part to be fully controlled in situ to produce the dressings desired. In this review, recent developments in hydrogel-based wound dressings made using 3D printing are covered. The most common biosensors integrated with 3D printed hydrogels for wound dressing applications are comprehensively discussed. Fundamental challenges for 3D printing and future prospects are highlighted. Additionally, some related nanomaterial-based hydrogels are recommended for future consideration.

Keywords: 3D printing; bioprinting; drug delivery; sensor-integrated bandages; wound dressings.

Figure 2

(a) iDr or mobile app., (b) matrix metalloproteinase (MMP), (c) skin wound healing process: (i) hemostasis (blood clotting), (ii) inflammation, (iii) tissue growth (proliferation), and (iv) tissue remodeling (maturation) [68,69,70].

Figure 3

(a) Single network of pHEMA, (b) single network of Gel-MAA, (c) porous double network, (d) SEM image polyHEMA, (e) SEM of polyMAA, (f) SEM of the co-polymerized HEMA/MAA.

Figure 1

(a) Skin structure, (b) conventional wound dressing, (c) wound structure, (d) types of wounds and curing system, (e) VAT polymerization 3D printing system, and the produced hydrogel wound dressing.

Figure 4

Classification of 3D printing based on printing techniques, material usage, and accuracy.

Figure 5

(a) DLP printer, (b) DLP printing general strategy, (c) SLA, and (d) photo-polymerization of DLP and SLA technologies.

Figure 6

(a) Tension load applied perpendicular to the layers, (b) tension load applied parallel to the layers, (c) the printing orientation, (d) the correlation of the temperature and the stress [158], and (e,f) the correlation between the tensile strength, Young’s modulus, and the printing orientation [160].

Figure 7

(a) Synthesis of the quaternized chitosan (QCS), (b) synthesis of the reduction graphene oxide coated by polydopamine (rGO-PDA), (c) schematic for the preparation process of the QCS/rGO-PDA/PNIPAm hydrogel and its properties: (1) conductivity, (2) tissue adhesion, (3) antibacterial activity, (4) self-healing, and (5) thermo-responsive self-contraction. (d) schematic showing the wound closure by assisting the thermos-responsive hydrogel (QCS/rGO-PDA/PNIPAm) [202].

Figure 8

(a) Electronic sensors integrated with hydrogels [174], (b) the general strategy of hydrogel-based sensors, and (c) wearable sensor with conductive self-healing hydrogels [209].