title: Injectable and porous PLGA microspheres that form highly porous scaffolds at body temperature.
abstract: Injectable scaffolds are of interest in the field of regenerative medicine because of their minimally invasive mode of delivery. For tissue repair applications, it is essential that such scaffolds have the mechanical properties, porosity and pore diameter to support the formation of new tissue. In the current study, porous poly(dl-lactic acid-co-glycolic acid) (PLGA) microspheres were fabricated with an average size of 84±24μm for use as injectable cell carriers. Treatment with ethanolic sodium hydroxide for 2min was observed to increase surface porosity without causing the microsphere structure to disintegrate. This surface treatment also enabled the microspheres to fuse together at 37°C to form scaffold structures. The average compressive strength of the scaffolds after 24h at 37°C was 0.9±0.1MPa, and the average Young's modulus was 9.4±1.2MPa. Scaffold porosity levels were 81.6% on average, with a mean pore diameter of 54±38μm. This study demonstrates a method for fabricating porous PLGA microspheres that form solid porous scaffolds at body temperature, creating an injectable system capable of supporting NIH-3T3 cell attachment and proliferation in vitro.
authors.affiliation: School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Omar
authors.initials: O
authors.lastname: Qutachi
authors.affiliation: Institute for Biomechanics, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich, Switzerland.
authors.forename: Jolanda R
authors.initials: JR
authors.lastname: Vetsch
authors.affiliation: RegenTec Ltd, Biocity Nottingham, Pennyfoot Street, Nottingham NG1 1GF, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Gill
authors.affiliation: RegenTec Ltd, Biocity Nottingham, Pennyfoot Street, Nottingham NG1 1GF, UK.
authors.forename: Helen
authors.initials: H
authors.lastname: Cox
authors.affiliation: School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Scurr
authors.affiliation: Institute for Biomechanics, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich, Switzerland.
authors.forename: Sandra
authors.initials: S
authors.lastname: Hofmann
authors.affiliation: Institute for Biomechanics, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich, Switzerland.
authors.forename: Ralph
authors.initials: R
authors.lastname: Müller
authors.affiliation: RegenTec Ltd, Biocity Nottingham, Pennyfoot Street, Nottingham NG1 1GF, UK.
authors.forename: Robin A
authors.initials: RA
authors.lastname: Quirk
authors.affiliation: School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Shakesheff
authors.affiliation: School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK. Electronic address: cheryl.rahman@nottingham.ac.uk.
authors.forename: Cheryl V
authors.initials: CV
authors.lastname: Rahman
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000008:administration & dosage / Q000138:chemical synthesis*; D001831:Body Temperature / Q000502:physiology*; D002448:Cell Adhesion / Q000502:physiology*; D049109:Cell Proliferation / Q000502:physiology*; D019544:Equipment Failure Analysis; D007267:Injections; D019344:Lactic Acid / Q000008:administration & dosage / Q000737:chemistry*; D008422:Materials Testing; D051379:Mice; D008863:Microspheres; D041681:NIH 3T3 Cells; D010316:Particle Size; D011100:Polyglycolic Acid / Q000008:administration & dosage / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D016062:Porosity; D011474:Prosthesis Design; D054457:Tissue Scaffolds
chemical_list: D001672:Biocompatible Materials; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid
keywords: Cell delivery; Microsphere; PLGA; Porosity; Scaffold