Platelet extracellular vesicles (PEVs) are emerging as key biomarkers in diabetes mellitus (DM), reflecting altered platelet function and coagulation pathways. This study compares two proteomic techniques—nanoLC-MALDI-MS/MS and nanoLC-TIMS-MS/MS—for analyzing PEVs in diabetic patients, to assess their potential for biomarker discovery. PEVs were isolated from platelet-rich plasma and characterized using tunable resistive pulse sensing (TRPS), Fourier-transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). Proteomic analyses identified significant differences in protein expression between diabetic and non-diabetic individuals, with nanoLC-TIMS-MS/MS demonstrating superior sensitivity by detecting 97% more unique proteins than nanoLC-MALDI-MS/MS. Key differentially expressed proteins included apolipoproteins and oxidative stress markers, which may contribute to platelet dysfunction and cardiovascular complications in DM. Sex-specific variations in protein expression were also observed, highlighting potential differences in disease progression between male and female patients. The integration of advanced proteomic methodologies provides novel insights into the role of PEVs in diabetes pathophysiology, underscoring their diagnostic and therapeutic potential. These findings pave the way for improved biomarker-based strategies for early detection and monitoring of diabetic complications.

The study of the conformational stability of protein layers at the interface between gold surfaces and lipid membranes is crucial for determining the biological activity of these systems and understanding their interactions. The surfaces differ significantly in hardness: gold is a rigid substrate, while the POPC/POPS liposome layer is highly flexible. A quartz crystal microbalance with dissipation (QCM-D) monitoring method and multi-parametric surface plasmon resonance (MP-SPR) were used to determine the adsorption efficiency of lysozymes, the level of layer hydration, and changes occurring within the secondary structure and the thickness of the formed protein layer. In both methods, lysozyme adsorption on the gold surface was more effective at pH 4.0 than at pH 7.4. The lysozyme adsorption efficiency on the surface of the lipid layer was the same for both measurement conditions. In contrast, the affinity of lysozyme molecules to the lipid surface was higher than that of the gold surface. The composition of the secondary structure of lysozymes was monitored using the FT-IR method. Deconvolution of the Amide I band confirms the existence of different mechanisms underlying lysozyme molecule immobilization depending on the type of adsorption surface. Along with the change in the surface, there is a transition from the dominance of electrostatic to hydrophobic interactions, which significantly affects the structure of the interphase layer. High content of random structures on the lipid surface is evident, while, in the case of the gold surface, there is a decrease in random structures and the presence of antiparallel β-sheets. Interaction with the surface induces the transition of amyloidogenic domains of the protein to conformations, which are particularly susceptible to aggregation, consequently leading to oligomerization.