Hyaluronic acid in Pluronic F-127/F-108 hydrogels for postoperative pain in arthroplasties: Influence on physico-chemical properties and structural requirements for sustained drug-release

In this study, we reported the hyaluronic acid (HA) on supramolecular structure of Pluronic F-127 (PLF-127) and/or Pluronic F-108 (PLF-127) hydrogels, as well as their effects on release mechanisms, looking forward their application as lidocaine (LDC) drug-delivery systems in arthroplastic surgeries. We have studied the HA-micelle interaction using Dynamic Light Scattering (DLS), the micellization and sol-gel transition processes by Differential Scanning Calorimetry (DSC) and Rheology., of PL-based hydrogels and. The presence of HA provided the formation of larger micellar dimensions from similar to 26.0 to 42.4 nm. The incorporation of HA did not change the micellization temperatures and stabilized hydrogels rheological properties (G' > G ''), showing no interference on PL-thermoreversible properties. Small-Angle-X-ray Scattering (SAXS) patterns revealed that HA incorporation effects were pronounced for PLF-127 and PLF-108 systems, showing transitions from lamellar to hexagonal phase organization (HA-PLF-127) and structural changes from cubic to gyroid and/or cubic to lamellar. The HA insertion effects were also observed on drug release profiles, since lower LDC release constants (K-rel = 0.24-0.41 mM.h(-1)) were observed for HA-PLF-127, that presented a hexagonal phase organization. Furthermore, the HA-PL systems presented reduced in vitro cytotoxic effects, pointed out their tendency to self assembly and possible application as drug delivery systems. (C) 2018 Elsevier B.V. All rights reserved.