SYNOVIAL JOINT FLUID CHROMATOGRAPHY OUTCOMES IN OSTEOARTHRITIS: DO AFFINITY SORBENTS IMPROVE THE OUTCOME OF MULTI-OMICS STUDIES?

Omics studies of the synovial joint fluid (SJF) may quantify the early diagnosis, progression and response to treatment in knee joint osteoarthritis (KOA). Developing affinity sorbents for analysis of SJF may enhance the emphasis of various metabolites. Our hypothesis was that sorbents will enhance the SJF chromatography outcomes during KOA multi-omics studies. We aimed to develop a microextraction sorbent for the selective detection of phospholipids (PLs). SiO 2 , SiO 2 @PEI and SiO 2 @PEI@Ti(IV) were chosen as candidate sorbents. We also identified metabolomic differences between post-traumatic and elderly individuals using a different extraction method for which we obtained preliminary studies. SJFs were treated with sorbents representing 3 different chromatographic separation methods and the results were examined by mass spectroscopy. The results of another separation technique which were obtained preliminary studies are also included. The SJFs were obtained from KOA patients at Hacettepe University Hospital after the approval of Hacettepe University Health Sciences Research Ethics Committee (#: 2023/09-44 date: 19 December 2023, Research no: SBA 23/262). Phospholipidomic examination was performed using the Q-TOF LC/MS. The aim of sorbent synthesis is to selectively determine inflammatory, degenerative and regenerative biomarkers. When the lipidomic data obtained by Q-TOF LC/MS were examined, it was observed that phosphatidylcholine, phosphatidylglycerol, phosphatidic acid and phosphatidylserine groups from the PLs found in SJF were predominantly enriched with the synthesized sorbent. The lipid fraction extracted from SJF by liquid-liquid extraction (LLE) method was examined in terms of PL enrichment performance by interacting with monodisperse-mesoporous SiO 2 microspheres. The lipid fraction extracted from SJF by LLE method was examined in terms of PL enrichment performance by interacting with SiO 2 microspheres. Extraction efficiency was evaluated based on 44 common peaks detected by both methods. In the preliminary results obtained with another extraction method, we found metabolomic differences between post-traumatic and elderly individuals. Conclusions. Diagnosis, treatment and monitoring of OA depend on various factors. Diagnosis is currently based on patient history, physical examination and medical imaging. Quantitative assessment of SJF may help determine treatment options, especially in young OA patients. There is a need to develop reliable and economical biomarker-based diagnostic kits, if possible before symptoms occur, and for monitoring the success of treatments.