title: Growth of a bonelike apatite on chitosan microparticles after a calcium silicate treatment.
abstract: Bioactive chitosan microparticles can be prepared successfully by treating them with a calcium silicate solution and then subsequently soaking them in simulated body fluid (SBF). Such a combination enables the development of bioactive microparticles that can be used for several applications in the medical field, including injectable biomaterial systems and tissue engineering carrier systems. Chitosan microparticles, 0.6microm in average size, were soaked either for 12h in fresh calcium silicate solution (condition I) or for 1h in calcium silicate solution that had been aged for 24h before use (condition II). Afterwards, they were dried in air at 60 degrees C for 24h. The samples were then soaked in SBF for 1, 3 and 7 days. After the condition I calcium silicate treatment and the subsequent soaking in SBF, the microparticles formed a dense apatite layer after only 7 days of immersion, which is believed to be due to the formation of silanol (Si-OH) groups effective for apatite formation. For condition II, the microparticles successfully formed an apatite layer on their surfaces in SBF within only 1 day of immersion.
authors.affiliation: 3B's Research Group, Department of Polymer Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal. belinha@dep.uminho.pt
authors.forename: I B
authors.initials: IB
authors.lastname: Leonor
authors.forename: E T
authors.initials: ET
authors.lastname: Baran
authors.forename: M
authors.initials: M
authors.lastname: Kawashita
authors.forename: R L
authors.initials: RL
authors.lastname: Reis
authors.forename: T
authors.initials: T
authors.lastname: Kokubo
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D001031:Apatites / Q000737:chemistry*; D001826:Body Fluids / Q000737:chemistry*; D018786:Bone Substitutes / Q000138:chemical synthesis*; D017610:Calcium Compounds / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D008422:Materials Testing; D010316:Particle Size; D017640:Silicates / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D001031:Apatites; D018786:Bone Substitutes; D017610:Calcium Compounds; D020099:Coated Materials, Biocompatible; D017640:Silicates; D048271:Chitosan; C031293:calcium silicate