title: 3D bone tissue engineered with bioactive microspheres in simulated microgravity.
abstract: Three-dimensional (3D) osteoblast cell cultures were obtained in rotating-wall vessels (RWV), simulating microgravity. Three types of bioactive microcarriers, specifically modified bioactive glass particles, bioceramic hollow microspheres, and biodegradable bioactive glass-polymer composite microspheres, were developed and used with osteoblasts. The surfaces of composite microspheres fully transformed into bone apatite after 2-wk immersion in simulated physiological fluid, which demonstrated their bone-bonding ability. The motion of microcarriers in RWVs was photographically recorded and numerically analyzed. The trajectories of hollow microspheres showed that they migrated and eventually stayed around at the central region of the RWV. At their surfaces, shear stresses were low. In contrast, solid glass or polymer particles moved toward and finally bounced off the outer wall of the RWVs. Cell culture studies in the RWV using bone marrow stromal cells showed that the cells attached to and formed 3D aggregates with the hollow microspheres. Extracellular matrix and mineralization were observed in the aggregates. Cell culture studies also confirmed the ability of the composite microspheres to support 3D bone-like tissue formation. These data suggest that the new hollow bioceramic microspheres and degradable composite microspheres can be used as microcarriers for 3D bone tissue engineering in microgravity. They also have potential applications as drug delivery systems.
authors.affiliation: Department of Bioengineering, Center for Bioactive Materials and Tissue Engineering, University of Pennsylvania, Philadelphia 19104, USA.
authors.forename: Q Q
authors.initials: QQ
authors.lastname: Qiu
authors.forename: P
authors.initials: P
authors.lastname: Ducheyne
authors.forename: P S
authors.initials: PS
authors.lastname: Ayyaswamy
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D002113:Calcification, Physiologic; D018929:Cell Culture Techniques; D018920:Coculture Techniques; D005109:Extracellular Matrix / Q000502:physiology; D005898:Glass; D008297:Male; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010006:Osteoblasts / Q000166:cytology*; D011108:Polymers; D051381:Rats; D012212:Rheology; D012399:Rotation; D017550:Spectroscopy, Fourier Transform Infrared; D017154:Stromal Cells / Q000166:cytology; D018474:Weightlessness Simulation
chemical_list: D011108:Polymers