title: Incorporation of sol-gel bioactive glass into PLGA improves mechanical properties and bioactivity of composite scaffolds and results in their osteoinductive properties.
abstract: In this study, 3D porous bioactive composite scaffolds were produced and evaluated for their physico-chemical and biological properties. Polymer poly-L-lactide-co-glycolide (PLGA) matrix scaffolds were modified with sol-gel-derived bioactive glasses (SBGs) of CaO-SiO2-P2O5 systems. We hypothesized that SBG incorporation into PLGA matrix would improve the chemical and biological activity of composite materials as well as their mechanical properties. We applied two bioactive glasses, designated as S2 or A2, differing in the content of SiO2 and CaO (i.e. 80 mol% SiO2, 16 mol% CaO for S2 and 40 mol% SiO2, 52 mol% CaO for A2). The composites were characterized for their porosity, bioactivity, microstructure and mechanical properties. The osteoinductive properties of these composites were evaluated in human bone marrow stromal cell (hBMSC) cultures grown in either standard growth medium or treated with recombinant human bone morphogenetic protein-2 (rhBMP-2) or dexamethasone (Dex). After incubation in simulated body fluid, calcium phosphate precipitates formed inside the pores of both A2-PLGA and S2-PLGA scaffolds. The compressive strength of the latter was increased slightly compared to PLGA. Both composites promoted superior hBMSC attachment to the material surface and stimulated the expression of several osteogenic markers in hBMSC compared to cells grown on unmodified PLGA. There were also marked differences in the response of hBMSC to composite scaffolds, depending on chemical compositions of the scaffolds and culture treatments. Compared to silica-rich S2-PLGA, hBMSC grown on calcium-rich A2-PLGA were overall less responsive to rhBMP-2 or Dex and the osteoinductive properties of these A2-PLGA scaffolds seemed partially dependent on their ability to induce BMP signaling in untreated hBMSC. Thus, beyond the ability of currently studied composites to enhance hBMSC osteogenesis, it may become possible to modulate the osteogenic response of hBMSC, depending on the chemistry of SBGs incorporated into polymer matrix.
authors.affiliation: Department of Cell Biology and Imaging, Faculty of Biology and Earth Sciences, Jagiellonian University, Gronostajowa 9, 30-387 Krakow, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Filipowska
authors.forename: J
authors.initials: J
authors.lastname: Pawlik
authors.forename: K
authors.initials: K
authors.lastname: Cholewa-Kowalska
authors.forename: G
authors.initials: G
authors.lastname: Tylko
authors.forename: E
authors.initials: E
authors.lastname: Pamula
authors.forename: L
authors.initials: L
authors.lastname: Niedzwiedzki
authors.forename: M
authors.initials: M
authors.lastname: Szuta
authors.forename: M
authors.initials: M
authors.lastname: Laczka
authors.forename: A M
authors.initials: AM
authors.lastname: Osyczka
mesh_terms: D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000737:chemistry; D001854:Bone Marrow Cells / Q000166:cytology; D018786:Bone Substitutes / Q000737:chemistry*; D001842:Bone and Bones / Q000737:chemistry*; D002470:Cell Survival; D002478:Cells, Cultured; D002516:Ceramics / Q000737:chemistry*; D003094:Collagen / Q000737:chemistry; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D008297:Male; D008422:Materials Testing; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D010012:Osteogenesis; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D017154:Stromal Cells / Q000166:cytology; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: C022107:Bioglass; D018786:Bone Substitutes; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D012822:Silicon Dioxide; D003094:Collagen; D000469:Alkaline Phosphatase