Rheological characterization of new thermosensitive hydrogels formed by chitosan, glycerophosphate, and phosphorylated β-cyclodextrin

A novel thermosensitive hydrogel consisting of phosphorylated β-cyclodextrin (βCD-PH), β-cyclodextrin (βCD) and chitosan was prepared by embedding βCD and βCD-PH, into the well-studied chitosan/αβ-glycerophosphate system (CS/αβGP). The relevance of this work is the use of βCD-PH to partially substitute αβGP as the gelling agent. The role of βCD and βCD-PH on the rheological properties of hydrogels, gelation time, and gelation temperature were investigated. The gelation time for all the samples (CS/αβGP, CS/αβGP/βCD, and CS/αβGP/βCD-PH) was less than a minute at 37 °C, which is suitable for biomedical applications. The gelation temperature for hydrogel CS/αβGP/βCD-PH increased linearly with the addition of βCD-PH within the interval 31.8-37.3 °C, at ratios CS:βCD-PH of 1:0.5, 1:1, 1:1.5 and 1:2 (w/w). The hydrogel thus obtained has potential applications in dual drug delivery (hydrophilic and hydrophobic).