title: Monodisperse gelatin microspheres as a drug delivery vehicle: release profile and effect of crosslinking density.
abstract: Uniform gelatin microspheres (GMS) of a wet size of 100 microm in diameter were fabricated by the electric field assisted precision particle fabrication (E-PPF) method and crosslinked with different glutaraldehyde (GA) concentrations to study the effect of the crosslinking density on drug release. The drug release profiles of the crosslinked GMS were studied along with the intraparticle drug distribution and the particle degradation characteristics. Due to the concentration gradient of GA along the diffusion path into the GMS, the crosslinking density is higher on the GMS surface, making it less susceptible to degradation. As a result, the GMS with higher GA concentrations (0.375-0.875%) exhibited a highly resistant surface toward enzymatic degradation. On the other hand, the amount of drug complexation at the surface decreases as the GA concentration increases, which can be attributed to the lowered basicity of gelatin caused by the increased crosslinking density. These factors collectively affect the drug release kinetics and give rise to similar release profiles for GMS above a GA concentration of 0.375%.
authors.affiliation: Thin Film and Charged Particle Research Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 1406 West Green Street, Urbana, Illinois 61801, USA.
authors.forename: Young Bin
authors.initials: YB
authors.lastname: Choy
authors.forename: Felice
authors.initials: F
authors.lastname: Cheng
authors.forename: Hyungsoo
authors.initials: H
authors.lastname: Choi
authors.forename: Kyekyoon Kevin
authors.initials: KK
authors.lastname: Kim
mesh_terms: D003432:Cross-Linking Reagents / Q000737:chemistry*; D016503:Drug Delivery Systems; D005456:Fluorescent Dyes / Q000737:chemistry*; D005780:Gelatin / Q000737:chemistry*; D005976:Glutaral / Q000737:chemistry*; D007700:Kinetics; D008863:Microspheres; D010316:Particle Size; D014343:Trypan Blue / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D005456:Fluorescent Dyes; D005780:Gelatin; D014343:Trypan Blue; D005976:Glutaral