Understanding
the
dose-dependent effect of over-the-counter drugs
on red blood cells (RBCs) is crucial for hematology and digital pathology.
Yet, it is challenging to continuously record the real-time, drug-induced
shape changes of RBCs in a label-free manner. Here, we demonstrate
digital holotomography (DHTM)-enabled real-time, label-free concentration-dependent
and time-dependent monitoring of ibuprofen on RBCs from a healthy
donor. The RBCs are segmented based on three-dimensional (3D) and
four-dimensional (4D) refractive index tomograms, and their morphological
and chemical parameters are retrieved with their shapes classified
using machine learning. We directly observed the formation and motion
of spicules on the RBC membrane when aqueous solutions of ibuprofen
were drop-cast on wet blood, creating rough-membraned echinocyte forms.
At low concentrations of 0.25–0.50 mM, the ibuprofen-induced
morphological change was transient, but at high concentrations (1–3
mM) the spiculated RBC remained over a period of up to 1.5 h. Molecular
simulations confirmed that aggregates of ibuprofen molecules at high
concentrations significantly disrupted the RBC membrane structural
integrity and lipid order but produced negligible effect at low ibuprofen
concentrations. Control experiments on the effect of urea, hydrogen
peroxide, and aqueous solutions on RBCs showed zero spicule formation.
Our work clarifies the dose-dependent chemical effects on RBCs using
label-free microscopes that can be deployed for the rapid detection
of overdosage of over-the-counter and prescribed drugs.