Characterization of Injectable Smart Hydrogels

Abstract

Injectable smart hydrogels are water-swollen polymeric structures able to respond to different stimuli such as changes in temperature or pH. They also allow minimally invasive administration, which greatly increases their translational potential. The characterization of these biomaterials is essential to understand their functionality and to ensure their directed development. Due to the unique characteristics of injectable smart hydrogels, several tests should be performed before and after their gelation or stimuli-induced changes. However, there is a lack of standardized methodology for assessing hydrogel properties as well as great heterogeneity in how they are characterized. Throughout this chapter, different characterization techniques to assess these properties as well as key considerations for adequately characterizing smart injectable hydrogels will be discussed. Among the main properties that need characterization, hydrogel rheology, structure, morphology, stability, degradation, cargo release and biocompatibility are discussed. Establishing how they should be characterized will facilitate their translation towards the clinic.