title: Physicomechanical properties of sintered scaffolds formed from porous and protein-loaded poly(DL-lactic-co-glycolic acid) microspheres for potential use in bone tissue engineering.
abstract: An injectable poly(DL-lactic-co-glycolic acid) (PLGA) system comprising both porous and protein-loaded microspheres capable of forming porous scaffolds at body temperature was developed for tissue regeneration purposes. Porous and non-porous (lysozyme loaded) PLGA microspheres were formulated to represent 'low molecular weight' 22-34 kDa, 'intermediate molecular weight' (IMW) 53 kDa and 'high molecular weight' 84-109 kDa PLGA microspheres. The respective average size of the microspheres was directly related to the polymer molecular weight. An initial burst release of lysozyme was observed from both microspheres and scaffolds on day 1. In the case of the lysozyme-loaded microspheres, this burst release was inversely related to the polymer molecular weight. Similarly, scaffolds loaded with 1 mg lysozyme/g of scaffold exhibited an inverse release relationship with polymer molecular weight. The burst release was highest amongst IMW scaffolds loaded with 2 and 3 mg/g. Sustained lysozyme release was observed after day 1 over 50 days (microspheres) and 30 days (scaffolds). The compressive strengths of the scaffolds were found to be inversely proportional to PLGA molecular weight at each lysozyme loading. Surface analysis indicated that some of the loaded lysozyme was distributed on the surfaces of the microspheres and thus responsible for the burst release observed. Overall the data demonstrates the potential of the scaffolds for use in tissue regeneration.
authors.affiliation: a School of Pharmacy , The University of Nottingham Malaysia Campus , 43500 Semenyih , Selangor , Malaysia.
authors.forename: Yamina
authors.initials: Y
authors.lastname: Boukari
authors.forename: David J
authors.initials: DJ
authors.lastname: Scurr
authors.forename: Omar
authors.initials: O
authors.lastname: Qutachi
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Morris
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Doughty
authors.forename: Cheryl V
authors.initials: CV
authors.lastname: Rahman
authors.forename: Nashiru
authors.initials: N
authors.lastname: Billa
mesh_terms: D000818:Animals; D019245:Compressive Strength; D004337:Drug Carriers / Q000737:chemistry; D065546:Drug Liberation; D005269:Femur / Q000166:cytology*; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing; D055595:Mechanical Phenomena; D008863:Microspheres; D008970:Molecular Weight; D009113:Muramidase / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D016062:Porosity; D051381:Rats; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D004337:Drug Carriers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D009113:Muramidase
keywords: BMP-2; PLGA; injectable; lysozyme; microsphere; porous; scaffold; tissue engineering