title: Nanocomposite scaffolds with tunable mechanical and degradation capabilities: co-delivery of bioactive agents for bone tissue engineering.
abstract: Novel multifunctional nanocomposite scaffolds made of nanobioactive glass and alginate crosslinked with therapeutic ions such as calcium and copper were developed for delivering therapeutic agents, in a highly controlled and sustainable manner, for bone tissue engineering. Alendronate, a well-known antiresorptive agent, was formulated into microspheres under optimized conditions and effectively loaded within the novel multifunctional scaffolds with a high encapsulation percentage. The size of the cation used for the alginate crosslinking impacted directly on porosity and viscoelastic properties, and thus, on the degradation rate and the release profile of copper, calcium and alendronate. According to this, even though highly porous structures were created with suitable pore sizes for cell ingrowth and vascularization in both cases, copper-crosslinked scaffolds showed higher values of porosity, elastic modulus, degradation rate and the amount of copper and alendronate released, when compared with calcium-crosslinked scaffolds. In addition, in all cases, the scaffolds showed bioactivity and mechanical properties close to the endogenous trabecular bone tissue in terms of viscoelasticity. Furthermore, the scaffolds showed osteogenic and angiogenic properties on bone and endothelial cells, respectively, and the extracts of the biomaterials used promoted the formation of blood vessels in an ex vivo model. These new bioactive nanocomposite scaffolds represent an exciting new class of therapeutic cell delivery carrier with tunable mechanical and degradation properties; potentially useful in the controlled and sustainable delivery of therapeutic agents with active roles in bone formation and angiogenesis, as well as in the support of cell proliferation and osteogenesis for bone tissue engineering.
authors: Department of Pharmaceutical Technology, Faculty of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, PC1113, Argentina.
authors: Juan P
authors: JP
authors: Cattalini
authors: Judith
authors: J
authors: Roether
authors: Alexander
authors: A
authors: Hoppe
authors: Fatemeh
authors: F
authors: Pishbin
authors: Luis
authors: L
authors: Haro Durand
authors: Alejandro
authors: A
authors: Gorustovich
authors: Aldo R
authors: AR
authors: Boccaccini
authors: Silvia
authors: S
authors: Lucangioli
authors: Viviana
authors: V
authors: Mouriño
mesh_terms: D019386:Alendronate / Q000737:chemistry; D000464:Alginates / Q000737:chemistry; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001854:Bone Marrow Cells / Q000166:cytology; D001862:Bone Resorption; D001842:Bone and Bones / Q000502:physiology*; D002118:Calcium / Q000737:chemistry; D002470:Cell Survival; D049033:Chorioallantoic Membrane / Q000378:metabolism; D019245:Compressive Strength; D003300:Copper / Q000737:chemistry; D003370:Coturnix; D003432:Cross-Linking Reagents / Q000737:chemistry; D004548:Elasticity; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D059630:Mesenchymal Stem Cells / Q000166:cytology; D008863:Microspheres; D053761:Nanocomposites / Q000737:chemistry*; D010012:Osteogenesis; D016062:Porosity; D051381:Rats; D017207:Rats, Sprague-Dawley; D013314:Stress, Mechanical; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*; D014783:Viscosity
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D006603:Hexuronic Acids; D003300:Copper; D020723:Glucuronic Acid; D002118:Calcium; D019386:Alendronate