title: Accelerating protein release from microparticles for regenerative medicine applications.
abstract: There is a need to control the spatio-temporal release kinetics of growth factors in order to mitigate current usage of high doses. A novel delivery system, capable of providing both structural support and controlled release kinetics, has been developed from PLGA microparticles. The inclusion of a hydrophilic PLGA-PEG-PLGA triblock copolymer altered release kinetics such that they were decoupled from polymer degradation. A quasi zero order release profile over four weeks was produced using 10% w/w PLGA-PEG-PLGA with 50:50 PLGA whereas complete and sustained release was achieved over ten days using 30% w/w PLGA-PEG-PLGA with 85:15 PLGA and over four days using 30% w/w PLGA-PEG-PLGA with 50:50 PLGA. These three formulations are promising candidates for delivery of growth factors such as BMP-2, PDGF and VEGF. Release profiles were also modified by mixing microparticles of two different formulations providing another route, not previously reported, for controlling release kinetics. This system provides customisable, localised and controlled delivery with adjustable release profiles, which will improve the efficacy and safety of recombinant growth factor delivery.
authors.affiliation: School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK. lisa.white@nottingham.ac.uk
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: White
authors.forename: Giles T S
authors.initials: GT
authors.lastname: Kirby
authors.forename: Helen C
authors.initials: HC
authors.lastname: Cox
authors.forename: Roozbeh
authors.initials: R
authors.lastname: Qodratnama
authors.forename: Omar
authors.initials: O
authors.lastname: Qutachi
authors.forename: Felicity R A J
authors.initials: FR
authors.lastname: Rose
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Shakesheff
mesh_terms: D019344:Lactic Acid / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D011092:Polyethylene Glycols / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011506:Proteins / Q000378:metabolism*; D044968:Regenerative Medicine
chemical_list: D011506:Proteins; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011092:Polyethylene Glycols