Vivien Wiltzsch (Leipzig, DE), Dr. Johannes R. Schmidt (Leipzig, DE), Daniela Bastos (Berlin, DE), Klaudia Adamowicz (Hamburg, DE), Dr. Tanja Laske (Hamburg, DE), Dr. Anke Hoffmann (Leipzig, DE), Dr. Jörg Lehmann (Leipzig, DE), Prof. Dr. Jan Baumbach (Hamburg, DE; Odense, DK), Dr. Patrina S.P. Poh (Berlin, DE), Prof. Dr. Stefan Kalkhof (Leipzig, DE; Coburg, DE)
Abstract text (incl. figure legends and references)
Despite advancements in treating complex bone fractures, impaired healing remains a common complication in patients comorbid with type 2 diabetes mellitus (T2DM). The interdisciplinary research consortium "SyMBoD" aims to address this issue by studying the dynamics between T2DM and PCL scaffold-guided fracture healing through in silico modeling and in/ex vivo evaluation of diabetic bone healing, including histologic, proteomic, and metabolomic analyses of blood and tissue.
Using a diabetic rat model with a critical-size femur defect, scaffold-supported regenerated and contralateral tissue at 21 or 42 days post-implantation was explanted and extracted for their metabolome and proteome. LC-MS/MS-based proteomic analyses were conducted on a quadrupole-Orbitrap mass spectrometer. Altered protein expression profiles were determined by pairwise comparisons of disease conditions and time points. Finally, results based on imaging information of longitudinal µCT and histological data were integrated.
By employing a novel multi-omics extraction protocol combined with multiplexed mass tagging, over 4,000 proteins were reproducibly quantified in 4 animals per disease group and per time point, allowing for a comprehensive description of bone healing. Functional analysis of differentially expressed proteins confirmed that the systemic diabetic state also impairs the metabolism in bone, entailing a dysregulated healing. More precisely, diabetic animals showed prolonged expression of inflammatory proteins at both secretory and cellular levels, while expressing fewer structural proteins of a soft callus tissue. Matching the protein profiles to the imaging data further supported this observation.
In summary, utilizing deep proteomic profiling of PCL-guided healing, this study unveils disturbed molecular processes of diabetic bone regeneration. It sets the groundwork for targeted scaffold optimization via biofunctionalization to address observed imbalances in healing pathways.