In contrast to liposomes, lipid nanoparticles (LNPs) or nanoemulsions, cross-linked lipid nanoparticles (crosLNPs) allow for a bulk loading mechanism of amphiphilic drugs (e.g., TMA-DPH) into the whole particle volume. This function is governed by cross-linked fatty acids (hydrolized polymer of epoxidized soybean oil - HPESO) that form a three-dimensional matrix of polar and apolar molecular environments. Here, we combine time-resolved fluorescence (TRF) with isothermal titration calorimetry (ITC) to study (1) the binding mechanism of amphiphilic drugs to HPESO and (2) the saturation point defining the particle’s loading capacity. This approach is further applied to pegylated lipids (e.g., polyoxyethylene 40 stearate) to determine the lipid amount required for sufficient steric stabilization during crosLNP development. In combination with screening efforts using dual centrifugation (DC)—a sterile and clinically orientated nanoparticle bedside preparation technique—this strategy enables a biophysics-driven drug delivery system (DDS) development that goes far beyond conventional nanoparticle screening by size, shape, and surface charge. Our study focuses on (1) molecular interactions between amphiphilic drugs and lipids with HPESO, (2) rational development of crosLNPs via dual centrifugation, and (3) interactions with human serum albumin (HSA) providing predictive insights into the in vivo performance after IV administration. This strategy represents a unique combination of fundamental biophysics and clinically oriented nanoparticle development. The structural and functional properties of crosLNPs are analyzed by isothermal titration calorimetry (ITC), time-resolved fluorescence (TRF), CryoTEM, and DLS.
Lembeck et al. (Sun,) studied this question.