Purpose
The synthesis of nanometer and submicrometer hollow particles could be a motivating way to imprint new therapeutic properties
into a chondroitin sulfate-based hydrogel formulation. The use of hollowed polymer structures as a formulation strategy is
expected to have an impact in the effective therapy in the treatment of rheumatoid arthritis.
Methods
Chemical modification of the chondroitin sulfate with glycidyl methacrylate (GMA) was performed in water under thermal and
acid stimuli. The hydrogel spheres were formed upon cross-linking reaction of modified chondroitin sulfate (CSM) in a water-in-benzyl
alcohol nano-droplet emulsion.
Results
1H NMR and 13C NMR spectra showed that the carbon–carbon π-bonds coming from the GMA were incorporated onto backbones of CS. 13C-CP/MAS NMR spectra revealed that the formation of the CSM hydrogel spheres during the dispersion stage occurred by way of
carbon–carbon π-bonds on the CSM structure. The spherical shapes of the particles with diameters in the range of 20 μm to
500 nm were very clearly verified by SEM images where the dark center and edge of the hollow spheres could be identified easily.
Conclusions
Nanometer- and submicrometer-sized hydrogel spheres with hollow interior were produced from chondroitin sulfate by using a
new strategy of hydrogel synthesis.
KEY WORDS chondroitin sulfate - free-radical polymerization - hollow spheres nanotechnology - hydrogel