The crosslinking degree controls the mechanical, rheological, and swelling properties of hyaluronic acid microparticles.
Viscosupplements, used for treating joint and cartilage diseases, restore the rheological properties of synovial fluid, regulate joint homeostasis and act as scaffolds for cell growth and tissue regeneration. Most viscosupplements are hydrogels composed of hyaluronic acid (HA) microparticles suspended in fluid HA. These microparticles are crosslinked with chemicals to assure their stability against enzyme degradation and to prolong the action of the viscosupplement. However, the crosslinking also modifies the mechanical, swelling and rheological properties of the HA microparticle hydrogels, with consequences on the effectiveness of the application. The aim of this study is to correlate the crosslinking degree (CD) with these properties to achieve modulation of HA/DVS microparticles through CD control. Because divinyl sulfone (DVS) is the usual crosslinker of HA in viscosupplements, we examined the effects of CD by preparing HA microparticles at 1:1, 2:1, 3:1, and 5:1 HA/DVS mass ratios. The CD was calculated from inductively coupled plasma spectrometry data. HA microparticles were previously sized to a mean diameter of 87.5 µm. Higher CD increased the viscoelasticity and the extrusion force and reduced the swelling of the HA microparticle hydrogels, which also showed Newtonian pseudoplastic behavior and were classified as covalent weak. The hydrogels were not cytotoxic to fibroblasts according to an MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay.
Department of Engineering of Materials and Bioprocesses, School of Chemical Engineering, University of Campinas (UNICAMP), 13083-970 Campinas, SP, Brazil.
Andréa Arruda Martins
AA
Shimojo
Aline Mara Barbosa
AM
Pires
Rafael
R
Lichy
Ana Amélia
AA
Rodrigues
Maria Helena Andrade
MH
Santana
D000818:Animals; D002470:Cell Survival; D002522:Chlorocebus aethiops; D003432:Cross-Linking Reagents / Q000737:chemistry*; D006820:Hyaluronic Acid / Q000737:chemistry*; D008422:Materials Testing; D014709:Vero Cells
D003432:Cross-Linking Reagents; D006820:Hyaluronic Acid
crosslinking; divinyl sulfone; hyaluronic acid; microparticles; viscosupplements