title: Nanometer- and submicrometer-sized hollow spheres of chondroitin sulfate as a potential formulation strategy for anti-inflammatory encapsulation.
abstract: OBJECTIVE
  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 pi-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 pi-bonds on the CSM structure. The spherical shapes of the particles with diameters in the range of 20 microm 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.
authors.affiliation: Faculdade de Engenharia Quíimica, Departamento de Sistemas Químicos e Informática DESQ, Universidade Estadual de Campinas, Zeferino Vaz, 13081-970, Campinas, SP, Brazil.
authors.forename: Adriano V
authors.initials: AV
authors.lastname: Reis
authors.forename: Marcos R
authors.initials: MR
authors.lastname: Guilherme
authors.forename: Luiz H C
authors.initials: LH
authors.lastname: Mattoso
authors.forename: Adley F
authors.initials: AF
authors.lastname: Rubira
authors.forename: Elias B
authors.initials: EB
authors.lastname: Tambourgi
authors.forename: Edvani C
authors.initials: EC
authors.lastname: Muniz
mesh_terms: D018501:Antirheumatic Agents / Q000737:chemistry*; D019905:Benzyl Alcohol / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D002809:Chondroitin Sulfates / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D004337:Drug Carriers; D004339:Drug Compounding; D004655:Emulsions; D004852:Epoxy Compounds / Q000737:chemistry; D020100:Hydrogels; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D008956:Models, Chemical; D054118:Nanospheres; D010316:Particle Size; D016062:Porosity; D013499:Surface Properties; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D018501:Antirheumatic Agents; D003432:Cross-Linking Reagents; D004337:Drug Carriers; D004655:Emulsions; D004852:Epoxy Compounds; D020100:Hydrogels; D008689:Methacrylates; D014867:Water; D002809:Chondroitin Sulfates; D019905:Benzyl Alcohol; C007870:glycidyl methacrylate