first_pagesettingsOrder Article Reprints Open AccessArticle Human Osteoblasts’ Response to Biomaterials for Subchondral Bone Regeneration in Standard and Aggressive Environments by Stefania Pagani 1ORCID,Manuela Salerno 2,*,Giuseppe Filardo 2,Janis Locs 3ORCID,Gerjo J.V.M. van Osch 4,5,6ORCID,Jana Vecstaudza 3,Laura Dolcini 7,Veronica Borsari 1ORCID,Milena Fini 8,Gianluca Giavaresi 1ORCID andMarta Columbaro 9ORCID 1 Surgical Sciences and Technologies, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy 2 Applied and Translational Research Center, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy 3 Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, LV-1007 Riga, Latvia 4 Department of Orthopedics and Sports Medicine, Erasmus MC, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands 5 Department of Otorhinolaryngology, Head and Neck Surgery, Erasmus MC, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands 6 Department of Biomechanical Engineering, Delft University of Technology, 2628 CD Delft, The Netherlands 7 Fin-Ceramica Faenza S.p.A, 48018 Faenza, Italy 8 Scientific Direction, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy 9 Electron Microscopy Platform, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy * Author to whom correspondence should be addressed. Int. J. Mol. Sci. 2023, 24(19), 14764; https://doi.org/10.3390/ijms241914764 Received: 7 August 2023 / Revised: 21 September 2023 / Accepted: 27 September 2023 / Published: 29 September 2023 (This article belongs to the Special Issue Nanotechnology in Bone and Cartilage Repair and Regeneration) Downloadkeyboard_arrow_down Browse Figures Review Reports Versions Notes Abstract Osteochondral lesions, when not properly treated, may evolve into osteoarthritis (OA), especially in the elderly population, where altered joint function and quality are usual. To date, a collagen/collagen–magnesium–hydroxyapatite (Col/Col-Mg-HAp) scaffold (OC) has demonstrated good clinical results, although suboptimal subchondral bone regeneration still limits its efficacy. This study was aimed at evaluating the in vitro osteogenic potential of this scaffold, functionalized with two different strategies: the addition of Bone Morphogenetic Protein-2 (BMP-2) and the incorporation of strontium (Sr)-ion-enriched amorphous calcium phosphate (Sr-ACP) granules. Human osteoblasts were seeded on the functionalized scaffolds (OC+BMP-2 and OC+Sr-ACP, compared to OC) under stress conditions reproduced with the addition of H2O2 to the culture system, as well as in normal conditions, and evaluated in terms of morphology, metabolic activity, gene expression, and matrix synthesis. The OC+BMP-2 scaffold supported a better osteoblast morphology and stimulated scaffold colonization, cell activity, and extracellular matrix secretion, especially in the stressed culture environment but also in normal culture conditions, with increased expression of genes related to osteoblast differentiation. In conclusion, the incorporation of BMP-2 into the Col/Col-Mg-HAp scaffold also represents an improvement of the osteochondral scaffold in more challenging conditions, supporting further preclinical studies to optimize it for use in clinical practice.