title: Initial design and physical characterization of a polymeric device for osmosis-driven delayed burst delivery of vaccines.
abstract: Achieving the combination of delayed and immediate release of a vaccine from a delivery device without applying external triggers remains elusive in implementing single administration vaccination strategies. Here a means of vaccine delivery is presented, which exploits osmosis to trigger delayed burst release of an active compound. Poly(ε-caprolactone) capsules of 2 mm diameter were prepared by dip-coating, and their burst pressure and release characteristics were evaluated. Burst pressures (in bar) increased with wall thickness (t in mm) following Pburst  = 131(.) t + 3(.) 4 (R(2)  = 0.93). Upon immersion in PBS, glucose solution-filled capsules burst after 8.7 ± 2.9 days. Copolymers of hydrophobic ε -caprolactone and hydrophilic polyethylene glycol were synthesized and their physico-chemical properties were assessed. With increasing hydrophilic content, the copolymer capsules showed increased water uptake rates and maximum weight increase, while the burst release was earlier: 5.6 ± 2.0 days and 1.9 ± 0.2 days for 5 and 10 wt% polyethylene glycol, respectively. The presented approach enables the reproducible preparation of capsules with high versatility in materials and properties, while these vaccine delivery vehicles can be prepared separately from, and independently of the active compound.
authors: Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, 4059, Queensland, Australia. f.p.w.melchels@umcutrecht.nl.|Department of Orthopaedics, University Medical Center Utrecht, Heidelberglaan 100, 3584, CX Utrecht, The Netherlands. f.p.w.melchels@umcutrecht.nl.
authors: Ferry P W
authors: FP
authors: Melchels
authors: Institut für Textiltechnik & Institut für Angewandte Medizintechnik, RWTH Aachen University, Templergraben 55, Aachen, Germany.
authors: Ingo
authors: I
authors: Fehr
authors: Institut für Textiltechnik & Institut für Angewandte Medizintechnik, RWTH Aachen University, Templergraben 55, Aachen, Germany.
authors: Annika S
authors: AS
authors: Reitz
authors: Institut für Textiltechnik & Institut für Angewandte Medizintechnik, RWTH Aachen University, Templergraben 55, Aachen, Germany.
authors: Urip
authors: U
authors: Dunker
authors: Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, 4059, Queensland, Australia.
authors: Kenneth W
authors: KW
authors: Beagley
authors: Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, 4059, Queensland, Australia.
authors: Tim R
authors: TR
authors: Dargaville
authors: Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, 4059, Queensland, Australia. dietmar.hutmacher@qut.edu.au.|Institute for Advanced Study, Technical University of Munich, Lichtenbergstraße 2 a, Garching, Germany. dietmar.hutmacher@qut.edu.au.
authors: Dietmar W
authors: DW
authors: Hutmacher
mesh_terms: D016503:Drug Delivery Systems / Q000295:instrumentation*; D009995:Osmosis; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011312:Pressure; D014611:Vaccination / Q000295:instrumentation*; D014867:Water
chemical_list: D011091:Polyesters; D014867:Water; C016240:polycaprolactone; D011092:Polyethylene Glycols
keywords: biodegradable polymers; burst release; osmosis; vaccine delivery