3D Bioprinted Osteogenic Tissue Models for In Vitro Drug Screening

Abstract

Metabolic bone disease affects hundreds of millions of people worldwide, and as a result, in vitro models of bone tissue have become essential tools to help analyze bone pathogenesis, develop drug screening, and test potential therapeutic strategies. Drugs that either promote or impair bone formation are in high demand for the treatment of metabolic bone diseases. These drugs work by targeting numerous signaling pathways responsible for regulating osteogenesis such as Hedgehog, Wnt/β-catenin, and PI3K-AKT. In this study, differentiated bone marrow-derived mesenchymal stem cell (BM-MSC) scaffold-free 3D bioprinted constructs and 2D monolayer cultures were utilized to screen four drugs predicted to either promote (Icariin and Purmorphamine) or impair osteogenesis (PD98059 and U0126). Osteogenic differentiation capacity was analyzed over a four week culture period by evaluating mineralization, alkaline phosphatase (ALP) activity, and osteogenesis related gene expression. Responses to drug treatment were observed in both 3D differentiated constructs and 2D monolayer cultures. After four weeks in culture, 3D differentiated constructs and 2D monolayer cultures treated with Icariin or Purmorphamine showed increased mineralization, ALP activity, and the gene expression of bone formation markers (BGLAP, SSP1, and COL1A1), signaling molecules (MAPK1, WNT1, and AKT1), and transcription factors (RUNX2 and GLI1) that regulate osteogenic differentiation relative to untreated. 3D differentiated constructs and 2D monolayer cultures treated with PD98059 or U0126 showed decreased mineralization, ALP activity, and the expression of the aforementioned genes BGLAP, SPP1, COL1A1, MAPK1, AKT1, RUNX2, and GLI1 relative to untreated. Differences in ALP activity and osteogenesis related gene expression relative to untreated cells cultured in a 2D monolayer were greater in 3D constructs compared to 2D monolayer cultures. These findings suggest that our bioprinted bone model system offers a more sensitive, biologically relevant drug screening platform than traditional 2D monolayer in vitro testing platforms.

Revolutionizing Disease Modeling: The Emergence of Organoids in Cellular Systems

“…Bioinks are printable biomaterials used in 3D printing that are important for precision medicine due to the use of tissue organoids with diverse applications, such as drug screening (testing the efficacy and toxicity of drugs) or patient-derived xenografts [ 263 ]. Hence, the 3D bioprinting can be used to develop more physiologically relevant in vitro models for drug discovery and development [ 264 , 265 ].…”

Bioprinted in vitro tissue models: an emerging platform for developing therapeutic interventions and disease modelling

“…Enhanced osteogenesis as revealed through gene expression profiling, sensitive drug screening platform [41] Vascular tissue…”

Bioink: a 3D-bioprinting tool for anticancer drug discovery and cancer management

“…Similarly, a scaffold-less 3D bone model for the study of osteochondral defect repair and drug development has been produced. Starting from bone marrow-derived mesenchymal stem cells, an in vitro drug-testing platform was derived and used to investigate the effects of administered drugs on proto or impaired osteogenic differentiation in 3D and 2D cultures [62].…”