title: Assessment of polymer/bioactive glass-composite microporous spheres for tissue regeneration applications.
abstract: Conformable scaffold materials capable of rapid vascularization and tissue infiltration would be of value in the therapy of inaccessible wounds. Microporous spheres of poly(D,L-lactide-co-glycolide) (PLGA) containing bioactive glass (BG) were prepared using a thermally induced phase separation (TIPS) technique, and the bioactivity, in vitro degradation, and tissue integration of the microporous spheres were assessed. Microporous spheres containing 10% (w/w) BG stimulated a significant increase in vascular endothelial growth factor secretion from myofibroblasts consistently over a 10-day period (p < 0.01) compared with the neat PLGA microporous spheres. The microporous spheres degraded steadily in vitro over a 16-week period, with the neat PLGA microporous spheres retaining 82% of their original weight and microporous spheres containing 10% (w/w) BG retaining 77%. Both types of microporous spheres followed a similar pattern of size reduction throughout the degradation study, resulting in a 23% and 20% reduction after 16 weeks for the neat PLGA microporous spheres and PLGA microporous spheres containing 10% (w/w) BG, respectively (p < 0.01). After in vivo implantation into a subcutaneous wound model, the TIPS microporous spheres became rapidly integrated (interspherically and intraspherically) with host tissue, including vascularization of voids inside the microporous sphere. The unique properties of TIPS microporous spheres make them ideally suited for regenerative medicine applications where tissue augmentation is required.
authors.affiliation: Burdette Institute of Gastrointestinal Nursing, Kings College London, London, United Kingdom.
authors.forename: Hussila
authors.initials: H
authors.lastname: Keshaw
authors.forename: George
authors.initials: G
authors.lastname: Georgiou
authors.forename: Jonny J
authors.initials: JJ
authors.lastname: Blaker
authors.forename: Alastair
authors.initials: A
authors.lastname: Forbes
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Knowles
authors.forename: Richard M
authors.initials: RM
authors.lastname: Day
mesh_terms: D000818:Animals; D002470:Cell Survival; D002478:Cells, Cultured; D019245:Compressive Strength; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D005898:Glass / Q000737:chemistry*; D006801:Humans; D020007:Implants, Experimental; D019344:Lactic Acid / Q000737:chemistry*; D008422:Materials Testing / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D016062:Porosity; D051381:Rats; D012038:Regeneration; D040521:Subcutaneous Tissue / Q000378:metabolism; D023822:Tissue Engineering / Q000379:methods*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D042461:Vascular Endothelial Growth Factor A; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid