title: Preparation and drug controlled release of porous octyl-dextran microspheres.
abstract: In this work, porous octyl-dextran microspheres with excellent properties were prepared by two steps. Firstly, dextran microspheres were synthesized by reversed-phase suspension polymerization. Secondly, octyl-dextran microspheres were prepared by the reaction between dextran microspheres and ethylhexyl glycidyl ether and freezing-drying method. Porous structure of microspheres was formed through the interaction between octyl groups and organic solvents. The structure, morphology, dry density, porosity and equilibrium water content of porous octyl-dextran microspheres were systematically investigated. The octyl content affected the properties of microspheres. The results showed that the dry density of microspheres decreased from 2.35 to 1.21 g/ml, porosity increased from 80.68 to 95.05% with the octyl content increasing from 0.49 to 2.28 mmol/g. Meanwhile, the equilibrium water content presented a peak value (90.18%) when the octyl content was 2.25 mmol/g. Octyl-dextran microspheres showed high capacity. Naturally drug carriers play an important role in drug-delivery systems for their biodegradability, wide raw materials sources and nontoxicity. Doxorubicin (DOX) was used as a drug model to examine the drug-loading capacity of porous octyl-dextran microspheres. The drug-loading efficiency increased with the increase in microspheres/drug ratio, while the encapsulation efficiency decreased. When microspheres/drug mass ratio was 4/1, the drug-loading efficiency and encapsulation efficiency were 10.20 and 51.00%, respectively. The release rate of DOX increased as drug content and porosity increased. In conclusion, porous octyl-dextran microspheres were synthesized successfully and have the potential to serve as an effective delivery system in drug controlled release.
authors.affiliation: a Tianjin Key Laboratory of Composite and Functional Materials , Tianjin 300072 , P.R. China.
authors.forename: Xin
authors.initials: X
authors.lastname: Hou
authors.forename: Yanfei
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage* / Q000493:pharmacokinetics; D003692:Delayed-Action Preparations / Q000138:chemical synthesis / Q000737:chemistry; D003911:Dextrans / Q000138:chemical synthesis / Q000737:chemistry; D004317:Doxorubicin / Q000008:administration & dosage* / Q000493:pharmacokinetics; D005612:Freeze Drying; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D016062:Porosity; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000903:Antibiotics, Antineoplastic; D003692:Delayed-Action Preparations; D003911:Dextrans; D012997:Solvents; D014867:Water; D004317:Doxorubicin
keywords: drug controlled release; freezing-drying; octyl-dextran microsphere; porous structure