Differential behaviour and gene expression in 3D cultures of femoral‐ and calvarial‐derived human osteoblasts under a cyclic compressive mechanical load

• Published in: European journal of oral sciences Vol. 129; no. 6; pp. e12818 - n/a
• Main Authors: Itskovich, Yana, Meikle, Murray C, Cannon, Richard D, Farella, Mauro, Coates, Dawn E, Milne, Trudy J
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01-12-2021
• Subjects: Biomedical materials; bone engineering; Bone morphogenetic protein 2; Cell culture; Cell viability; Collagen (type I); compressive load; Compressive properties; Cyclic loads; Durapatite; Encapsulation; Femur; Gelatin; Gene Expression; Humans; Hyaluronic acid; hydrogel; Hydrogels; Hydroxyapatite; maxillofacial development; Mechanical loading; Mechanical properties; Mineralization; Osteoblasts; Polyethylene glycol; Stress, Mechanical; compressive load; bone engineering; maxillofacial development; hydrogel
• ISSN: 0909-8836; 1600-0722
• DOI: 10.1111/eos.12818

The aim of the study was to compare the response of calvarial and femoral osteoblasts cultured in a 3D hydrogel environment to cyclic compressive mechanical loading. Human foetal femoral and calvarial osteoblasts were encapsulated in a semi‐synthetic thiol‐modified hyaluronan gelatin polyethylene glycol diacrylate (PEGDA) cross‐linked HyStemC hydrogel. Constructs were subjected to a cyclic compressive strain of 33.4 kPa force every second for 5 s every hour for 6 h per day using FlexCell BioPress culture plates and compared to non‐compressed constructs. Cell viability, mineralisation, and morphological changes were observed over 21 days. BMP2, ALP, COL1A1, COL2A1, and OCN gene expression levels were quantified. Encapsulated osteoblast numbers increased and formed hydroxyapatite over a 21‐day period. Cell viability decreased under a cyclical strain when compared to cells under no strain. Femoral osteoblasts under strain expressed increased levels of BMP2 (53.9‐fold) and COL1A1 (5.1‐fold) mRNA compared to no strain constructs. Surprisingly, no BMP2 mRNA was detected in calvarial osteoblasts. Osteoblasts derived from endochondral (femoral) and intra‐membranous (calvarial) processes behaved differently in 3D‐constructs. We therefore recommend that site‐specific osteoblasts be used for future bone engineering and bone replacement materials and further research undertaken to elucidate how site‐specific osteoblasts respond to cyclic compressive loads.