title: Biodegradable polymer microcapsules fabrication through a template-free approach.
abstract: A detailed study on the direct synthesis of biocompatible polyesters (e.g., PLA, PLGA or PCL) microcapsules and multifunctional microcapsules, which does not require any template and core removal, is presented. The technique is based on the modified self-emulsification process within the emulsion droplets by simply adding sodium dioctyl sulfosuccinate (Aerosol OT or AOT) as a cosurfactant to the initial polymer solution, followed by double emulsion formation due to the coalescence of the internal water droplets. Microcapsules with tunable sizes (ranging from hundreds of nanometers to tens of micrometers) and morphologies were then obtained through solidification of droplet shell of the double emulsion via solvent removal. In this report, we have systematically investigated the effect of experimental parameters, such as polymer and AOT concentration, polymer molecular weight on the double emulsion formation process, and the final morphologies of the microcapsules. We demonstrate that the capsules can encapsulate either hydrophobic or hydrophilic dyes during solvent evaporation. Dye-release studies show a correlation between shell thickness, capsules size, and diffusive release rate, providing insights into the shell formation and shell thickness processing. Moreover, hydrophobic nanoparticles, such as oleic-acid coated Fe(3)O(4) nanoparticles and quantum dots, can also be incorporated into the walls of the microcapsules. Such functional microcapsules might find applications in the fields of controlled release, bioimaging, diagnostics, and targeting.
authors.affiliation: Hubei Key Lab of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074 China.
authors.forename: Xi
authors.initials: X
authors.lastname: Yu
authors.forename: Ziliang
authors.initials: Z
authors.lastname: Zhao
authors.forename: Wei
authors.initials: W
authors.lastname: Nie
authors.forename: Renhua
authors.initials: R
authors.lastname: Deng
authors.forename: Shanqin
authors.initials: S
authors.lastname: Liu
authors.forename: Ruijing
authors.initials: R
authors.lastname: Liang
authors.forename: Jintao
authors.initials: J
authors.lastname: Zhu
authors.forename: Xiangling
authors.initials: X
authors.lastname: Ji
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry; D002214:Capsules / Q000138:chemical synthesis* / Q000737:chemistry*; D004655:Emulsions; D057927:Hydrophobic and Hydrophilic Interactions; D011091:Polyesters / Q000138:chemical synthesis / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D002214:Capsules; D004655:Emulsions; D011091:Polyesters; D011108:Polymers