Bio-Inspired lipid nanovesicles (iNVs) incorporating membrane proteins from healthy tendon stem cells for targeted protein restoration in tendinopathic in vitro model

The potential of human tendon-stem-cell-inspired nanovesicles (hTSC-iNVs) to act as a delivery platform for Tenomodulin (TNMD), a membrane glycoprotein essential for restoring function in pathological tendon stem cells, was investigated. Membrane proteins extracted from healthy TSCs were incorporated into Single Unilamellar Vesicles (SUVs) generated through microfluidic technology. Two formulations, iNVs-20 and iNVs-300, were produced using distinct protein-to-lipid ratios. These conditions resulted in protein loadings of 23 µg/mg for iNVs-20 and 2.5 µg/mg for iNVs-300, expressed as protein per milligram of total lipid. Physicochemical characterization showed that iNVs-20 had a larger mean diameter (188 ± 59.4 nm; PDI 0.10) and moderate ζ- potential (-11.3 mV), whereas iNVs-300 were smaller (149 ± 58 nm; PDI 0.15) with a more negative ζ-potential (-58.6 mV), potentially reflecting differences in the amount of loaded proteins. Approximately 90% of vesicles in both formulations successfully incorporated TNMD. Both types exhibited minimal cytotoxicity and were efficiently internalized by tendinopathic TSCs, leading to increased TNMD expression. iNVs-300 delivered the highest protein amount to pathological cells. Western blot and immunofluorescence analyses confirmed a time-dependent rise in higher-glycosylated form of TNMD after 48 h, demonstrating effective delivery that preserves functional post-translational modifications.