The dermal side was used for the printing surface, the cell seeding surface, and the dura mater interface (printed dermal side was placed against the dura and experiments were therefore used only after a minimum of 2 days in PBS. Spatial control of osteoblastic differentiation of C2C12 cells seeded upon BMP-2-printed patterns of DermaMatrix was demonstrated using ALP staining (Fig. considered in part a recapitulation of embryogenesis. It involves complex spatial and temporal signaling interactions that direct all cell behaviors, including differentiation.7C13 Biological patterning involves the creation of persistent patterns of a broad array of growth factors and their modifying molecules, leading to functional organization of multiple tissue types and organs. Extracellular matrix (ECM) molecules such as proteoglycans can sequester growth factors within the surrounding ECM or on the cell surface to modify growth factor function either negatively or positively.14 Growth factor sequestration directly affects temporal and spatial function by presenting growth factors at specific locations in the ECM or on the cell surface15C21 at picomolar to nanomolar concentrations.22C26 We previously demonstrated the application of inkjet-based biopatterning to print bio-inks of dilute aqueous solutions of native growth factors onto native ECM substrates to Imeglimin hydrochloride make persistent two-dimensional (2D) patterns.27C31 In this context, the term 2D means surface Imeglimin hydrochloride patterning limited to printing bio-inks onto thin substrates of ECM films, such as a 10-nm-thick layer of fibrin crosslinked to glass slides. The growth factors were immobilized to the ECM substrates by taking advantage of the inherent native binding capacities between growth factors and ECM components.32,33 These patterns were then used to direct cell fates applications where three-dimensional (3D) constructs and patterns are required. To investigate this, we adapted our 2D biopatterning methodology to make 3D patterned constructs. Bio-inks were printed onto a sheet of porous scaffold material whereby they absorbed into and bound to the scaffold to form 3D patterned constructs. The primary requirements for 3D printing substrate materials are Imeglimin hydrochloride (1) open porosity and hydrophilicity for absorbing and internalizing a surface-applied bio-ink; (2) innate binding capacity for a broad range of growth factors and their modifiers; and (3) appropriate physical characteristics making them easy to handle during application. In addition, for use in investigations focusing on the role of growth factors in driving differentiation, these materials should possess relatively neutral material properties Imeglimin hydrochloride that do not have strong inherent stimulation capacity for any specific tissue type. It is important to emphasize that many surgically created wound sites do not require the use of scaffold materials that possess the same biomechanical properties as the targeted Imeglimin hydrochloride tissue to be regenerated because the scaffold is meant to be completely remodeled. DermaMatrix? (Synthes, West Chester, PA) acellular dermal matrix fulfilled all these requirements. DermaMatrix is a human allograft material that maintains original dermal ECM architecture. It contains a range of ECM molecules, including collagens I and III, elastin, fibronectin, glycosaminoglycans, and proteoglycans, many of which can sequester or bind a broad range of growth factors and their modifiers. This article presents the adaptation of our 2D bioprinting methodology to create persistent 3D spatial patterns of growth factors and their modifiers in a delivery scaffold. The bioprinting approach was demonstrated using printed bone morphogenetic protein-2 (BMP-2)/DermaMatrix constructs to spatially direct and restrict cellular differentiation down the osteogenic lineage and bone formation in a mouse calvarial defect model. Patterns of noggin, an inhibitor of BMP-2,35 were also printed adjacent to the BMP-2 patterns to investigate fine control over patterned response discrimination. The fidelity of spatial restriction of osteoblastic differentiation and bone formation between neighboring BMP-2 and noggin patterns improved in Rabbit Polyclonal to NPY2R comparison with patterns without noggin. Importantly, osteoinductive responses to.
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