Extensive research has focused on developing effective and biocompatible
drugs and drug-delivery systems. Capsaicin, a natural compound found in
hot peppers, has potential therapeutic properties, such as pain relief and antiinflammatory effects. However, its clinical application is limited by low cellular
absorption, chemical instability, poor aqueous solubility, and some side effects,
such as skin irritation and burning sensation. Lecithin, a phospholipid with
biocompatibility and liposome-forming abilities, can be used in drug delivery
systems. Both capsaicin and lecithin exhibit hydrophilic and hydrophobic characteristics, allowing them to self-assemble in aqueous solutions for drug loading
and release.
Molecular docking and molecular dynamics, two crucial computational techniques in the fields of computational chemistry and structural biology, are
instrumental for scrutinizing molecular interactions, especially in the context
of drug discovery and protein-ligand interactions. In this study, we employ
these methodologies to investigate the self-assembly behaviour of capsaicin and
lecithin in an aqueous environment, revealing strong self-assembly into welldefined, arbitrarily shaped aggregates. The hydrophilic-hydrophobic nature of
the materials enables improved drug loading and controlled release. Furthermore, the carrier enhances the physicochemical properties of capsaicin by forming stable complexes through nonbonded interactions. These findings inform
the development of new drug delivery systems that utilize the self-assembly
properties of amphiphilic molecules to improve the delivery and effectiveness of
hydrophobic drugs.
The distance between the hydrophobic groups in capsaicin and lecithin appears to be smaller compared to the hydrophilic groups. The spacing ranges
from 0.33 to 0.62 nm and 1.28 to 1.48 nm, respectively, this variation is because
of an increased concentration of lecithin monomers, which ranges from 1-8. Increasing the concentration of lecithin has an impact on the rotation angle of
capsaicin at the centre, reducing it from 123° to less than 60° and increasing
the availability of water surrounding it. Additionally, an increase in lecithin
concentration affects the arrangement of atoms attached to it. For example,
the distance between the hydrogen of the hydroxyl group and the oxygen of
the methoxy group increases from 0.25nm to 0.44nm, allowing more water to
interact with capsaicin, thereby enhancing its ability to dissolve in water.
These observations suggest that hydrophobic groups play a crucial role in facilitating the rapid entrapment of capsaicin via hydrophobic forces. As the concentration of lecithin increases, the complex becomes more stable, strengthening
the hydrophobic forces that hold capsaicin tightly and reducing its flexibility,
which is crucial for effective loading and release.