Biopolymeric In Situ Hydrogels for Tissue Engineering and Bioimaging Applications

Abstract

BACKGROUND: Biopolymeric in situ hydrogels play a crucial role in the regenerative repair and replacement of infected or injured tissue. They possess excellent biodegradability and biocompatibility in the biological system, however only a few biopolymeric in situ hydrogels have been approved clinically. Researchers have been investigating new advancements and designs to restore tissue functions and structure, and these studies involve a composite of biometrics, cells and a combination of factors that can repair or regenerate damaged tissue. METHODS: Injectable hydrogels, cross-linking mechanisms, bioactive materials for injectable hydrogels, clinically applied injectable biopolymeric hydrogels and the bioimaging applications of hydrogels were reviewed. RESULTS: This article reviews the different types of biopolymeric injectable hydrogels, their gelation mechanisms, tissue engineering, clinical applications and their various in situ imaging techniques. CONCLUSION: The applications of bioactive injectable hydrogels and their bioimaging are a promising area in tissue engineering and regenerative medicine. There is a high demand for injectable hydrogels for in situ imaging.

Current hydrogel advances in physicochemical and biological response-driven biomedical application diversity

“…Apart from the above-mentioned application practices, hydrogels could be also extended to other biomedical fields, such as tissue fillers, 393 bioimaging, 394 biosensor, 395 conductive wearable/implantable biodevices, 66 , 67 soft robots, 396 etc. Hydrogel products used for cosmetic filler have been widely reported and evaluated, where HA gel is the mostly used.…”

Liquid-type plasma-controlled in situ crosslinking of silk-alginate injectable gel displayed better bioactivities and mechanical properties

“…Hydrogel consists of a three-dimensional crosslinked hydrophilic polymer network and can retain a large amount of water. Due to the water storage property, hydrogel presents biocompatibility and can encapsulate substances such as cells, proteins, and drugs for various medical purposes [ 36 ]. Moreover, tunable mechanical properties including stiffness and viscosity of hydrogel have made it possible to load them with injectable agents, as has gained interest because of their advantages of minimal invasiveness.…”

“…In situ gelation is essential for injectable hydrogels and should occur timely in easily achieved conditions without harmful stimulus [ 37 ]. Various physical and chemical crosslinking methods have been applied for in situ gelation, including ionic crosslinking, photo-crosslinking, stimuli sensitive crosslinking, and enzymatic crosslinking [ 36 , 37 ]. Since the ideal injectable hydrogel requires injectability, timely gelation after injection, biocompatibility, and biodegradability, it is not easy to design an appropriate crosslinking method [ 3 ].…”

Combination Therapy of Killing Diseases by Injectable Hydrogels: From Concept to Medical Applications

“…[ 30 ] Different methods are reported in the literature for chemical cross‐linking. [ 31 ] These methods lead to the formation of hydrogels with high mechanical properties, which can be utilized to prepare the IHs with long‐lasting features. [ 32 ] Overall, the typical cross‐linking strategies may do not have the potential to be specific for getting injectable gels but they are suitable for the fabrication of ordinary hydrogels.…”