Human placental extracts (HPE) contain a wide spectrum of biologically active molecules
including peptides, growth factors, and immunomodulatory proteins. Previous studies
indicate that storage conditions influence the biological properties of these extracts and
their interaction with erythrocytes. However, the molecular mechanisms underlying these
interactions remain poorly understood. The present study investigates the mechanistic
interaction between placental extract fractions and the erythrocyte membrane–cytoskeleton
system. Fractionated placental extracts were analyzed for their influence on erythrocyte
membrane stability, cytoskeleton organization, and cytosolic microviscosity. Biophysical
measurements including hemolysis assays, osmotic fragility tests, and electron paramagnetic resonance (EPR) spectroscopy were conducted. The findings demonstrate that specific low molecular weight fractions significantly alter erythrocyte membrane protein interactions, particularly those associated with the Band-3 protein complex. These changes are accompanied by modifications in cytosol microviscosity and membrane stability. The results provide new insights into the cellular mechanisms of placental extract activity and may contribute to the development of therapeutic applications in regenerative medicine and cryobiology.
