Injectable reactive oxygen and nitrogen species-controlling hydrogels for tissue regeneration: current status and future perspectives

Abstract

The dual role of reactive oxygen and nitrogen species (RONS) in physiological and pathological processes in biological systems has been widely reported. It has been recently suggested that the regulation of RONS levels under physiological and pathological conditions is a potential therapy to promote health and treat diseases, respectively. Injectable hydrogels have been emerging as promising biomaterials for RONS-related biomedical applications owing to their excellent biocompatibility, 3-dimensional (3D) and extracellular matrix-mimicking structures, tunable properties, and easy functionalization. These hydrogels have been developed as advanced injectable platforms for locally generating or scavenging RONS, depending on the specific conditions of the target disease. In this review article, the design principles and mechanism by which RONS are generated/scavenged from hydrogels are outlined alongside a discussion of their in vitro and in vivo evaluations. Additionally, we highlight the advantages and recent developments of these injectable RONS-controlling hydrogels for regenerative medicines and tissue engineering applications.

Oxygen-releasing biomaterials for regenerative medicine

“…However, higher levels, longer periods and accumulation at the wrong location of hydrogen peroxide can lead to oxidative stress. 102,106,107 Therefore, real-time sensitive monitoring of ROS in living tissues is of great importance to understanding the state of a tissue redox microenvironment. Although a number of electrochemical biosensors have been developed to accurately quantify ROS concentrations, invasive measurement approaches limit the flexibility of real-time monitoring.…”

Injectable smart stimuli-responsive hydrogels: pioneering advancements in biomedical applications

“…Hydrogels are three-dimensional water-swollen networks with hydrophilic nature crosslinked by various hydrophilic polymers via chemical covalent bonds, physical non-covalent bonds or a combination of both. [1][2][3][4] Meanwhile, hydrogels could be further classified as natural, synthetic or hybrid Wei Huang Prof. Wei Huang serves as the Director of the Department of Orthopedics at the First Affiliated Hospital of Chongqing Medical University, where he also holds the position of Director of the Orthopedics Laboratory. Additionally, he holds the position of Vice President of the Orthopedic Physicians Branch of the Chinese Medical Association.…”

“…Hydrogels are three-dimensional water-swollen networks with hydrophilic nature crosslinked by various hydrophilic polymers via chemical covalent bonds, physical non-covalent bonds or a combination of both. 1–4 Meanwhile, hydrogels could be further classified as natural, synthetic or hybrid based on the source of constituting materials. 4–6 Due to their excellent biocompatibility, extracellular matrix (ECM)-like structure and immensely tunable properties (modified through physical/chemical methods) for specific applications, hydrogels are one of the most widely utilized soft biomaterials in tissue engineering (providing mechanical support and scaffold for tissue regeneration, transporting drugs/cells/cytokines/bioactive molecules, etc .).…”

“…1–4 Meanwhile, hydrogels could be further classified as natural, synthetic or hybrid based on the source of constituting materials. 4–6 Due to their excellent biocompatibility, extracellular matrix (ECM)-like structure and immensely tunable properties (modified through physical/chemical methods) for specific applications, hydrogels are one of the most widely utilized soft biomaterials in tissue engineering (providing mechanical support and scaffold for tissue regeneration, transporting drugs/cells/cytokines/bioactive molecules, etc .). 2,7–13 After the first appearance of the term “hydrogel” in the scientific literature in 1894, 14 great progress has been made in hydrogels and related fields, especially in the last few decades.…”

Collagen-based injectable and self-healing hydrogel with multifunction for regenerative repairment of infected wounds

“…Owning to possessing the excellent properties such as biomimetic porosity and good water retention for creating a local moist ambience etc., hydrogels are desirable materials for facilitating the regenerative healing of wound tissues [ 7 ]. Additionally, hydrogels are also widely utilized as efficient carriers for functional nanoparticles and drug delivering, particularly as new platform materials for surgical dressing in biomedical applications [ 8 , 9 ].…”