NPs. Although it can be assumed that the highest NP concentration directly correlates with improved properties, a concentration threshold has often been observed. For instance, an excess of CS micelles hindered the reticulation of ALG, leading to a cracked surface that triggered premature drug release. Consequently, achieving an adequate micelle/gel ratio (i.e., its reduction) was crucial to effectively control the release. Similarly, only up to 5% w/v of inorganic minerals such as HAP and WKT could be mixed with pyrogallol-modified HA. At higher contents, their excessive involvement in ionic crosslinking interfered with the catecholmediated covalent reticulation, making the material easy to break (Figure ). Scale bar = 4 mm. Adapted with permission. Copyright 2020 Elsevier.