A New Bioink for Improved 3D Bioprinting of Bone-Like Constructs

Abstract

Bone tissue loss can occur due to disease, trauma or following surgery, in each case treatment involving the use of bone grafts or biomaterials is usually required. Recent development of three-dimensional (3D) bioprinting (3DBP) has enabled the printing of customized bone substitutes. Bioinks used for bone 3DBP employ various particulate phases such as ceramic and bioactive glass particles embedded in the bioink creating a composite. When composite bioinks are used for 3DBP based on extrusion, particles are heterogeneously distributed causing damage to cells due to stresses created during flow in the matrix of the composite. Therefore, the objective of this study was to develop cell-friendly osteopromotive bioink mitigating the risk of cell damage due to the flow of particles. Towards this end, we have linked organic and inorganic components, gelatin methacryloyl (GelMA) and Ag-doped bioactive glass (Ag-BaG), to produce a hybrid material, GelMA-Ag-BaG (GAB). The distribution of the elements present in the Ag-BaG in the resulting hybrid GAB structure was examined. Rheological properties of the resulting hydrogel and its printability, as well as the degree of swelling and degradation over time, were also evaluated. GAB was compared to GelMA alone and GelMA-Ag-BaG nanocomposites. Results showed the superiority of the hybrid GAB bioink in terms of homogenous distribution of the elements in the structure, rheological properties, printability, and degradation profiles. Accordingly, this new bioink represents a major advance for bone 3DBP.

Biomimetic Mineralization of Mn-Doped Biphasic Calcium Phosphate in the GelMa Hydrogel Acting as a Functional 3D Bioscaffold for Osteo Defect Repair

“…In this context, gelatin methacrylate and Mn-doped biphasic calcium phosphate (BCP) were selected as materials of choice for bone tissue regeneration. Gelatin methacrylate is a biocompatible, naturally derived polymer with the advantage of photo-cross-linking in the presence of a lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) photoinitiator. , BCP influences the degradability and regeneration capabilities based on the calcium-to-phosphate ratio . Biphasic calcium phosphate consists of hydroxyapatite and β-tricalcium phosphate, which significantly impacted bone tissue regeneration as per the reported literature. ,, Doping with trace elements gained popularity to stabilize the phase of ceramic structures as well as enhance the bioactivity of bulk materials. − Addition of manganese (Mn) doping has previously exhibited a positive impact on stem cell differentiation into specific lineages based on doping concentration. , …”

“…Gelatin methacrylate is a biocompatible, naturally derived polymer with the advantage of photo-cross-linking in the presence of a lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) photoinitiator. 21,22 BCP influences the degradability and regeneration capabilities based on the calcium-to-phosphate ratio. 23 Biphasic calcium phosphate consists of hydroxyapatite and β-tricalcium phosphate, which significantly impacted bone tissue regeneration as per the reported literature.…”

Smart Bioinks for the Printing of Human Tissue Models

“…A subset of functionalized bioinks would include composite bioinks as seen in Figure 1 . These bioinks are created when certain particles are introduced into the cell-laden polymer matrix through mixing, allowing composites to support cell growth and avoid the introduction of shear forces during extrusion [ 38 ]. This perspective piece will discuss the concepts of “smart” bioinks, a type of composite bioinks capable of controlled release in response to stimuli that can be used as part of the 3D bioprinting process.…”