Investigation of interaction between dexamethasone/pheniramine and trypsin by fluorescence, UV-vis, CD, and molecular docking

Controlled Release of Drugs from Extracellular Matrix-Derived Peptide-Based Nanovesicles through Tailored Noncovalent Interactions

Elastin-collagen nanovesicles (ECnV) have emerged as a promising platform for drug delivery due to their tunable physicochemical properties and biocompatibility. The potential of nine distinct ECnVs to serve as drug-delivery vehicles was investigated in this study, and it was demonstrated that various small-molecule cargo (e.g., dexamethasone, methotrexate, doxorubicin) can be encapsulated in and released from a set of ECnVs, with extents of loading and rates of release dictated by the composition of the elastin domain of the ECnV and the type of cargo. Elastin-like peptides (ELPs) and collagen-like peptides (CLPs) of various compositions were produced; the secondary structure of the corresponding peptides was determined using CD, and the morphology and average hydrodynamic diameter (∼100 nm) of the ECnVs were determined using TEM and DLS. It was observed that hydrophobic drugs exhibited slower release kinetics than hydrophilic drugs, but higher drug loading was achieved for the more hydrophilic Dox. The collagen-binding ability of the ECnVs was demonstrated through a 2D collagen-binding assay, suggesting the potential for longer retention times in collagen-enriched tissues or matrices. Sustained release of drugs for up to 7 days was observed and, taken together with the collagen-binding data, demonstrates the potential of this set of ECnVs as a versatile drug delivery vehicle for longer-term drug release of a variety of cargo. This study provides important insights into the drug delivery potential of ECnVs and offers useful information for future development of ECnV-based drug delivery systems for the treatment of various diseases.

Characterization of the interactions between Fulvic acid and Trypsin with Spectroscopic and Molecular Docking technology

The interaction mechanism between trypsin and fulvic acid was analyzed by multispectral method and molecular docking simulation. The fluorescence spectra showed that fulvic acid induced static quenching of trypsin. The validity of this conclusion was further substantiated through the computation of the binding constants. The thermodynamic parameters show that the reaction is mainly controlled by van der Waals force and hydrogen bond force, and the reaction is spontaneous. In addition, based on the obtained binding distance, there may be a non-radiative energy transfer between the two. The ultraviolet spectrum showed that fulvic acid could shift the absorption peak of trypsin, indicating that fulvic acid had an effect on the secondary structure of trypsin. According to the synchronous fluorescence spectrum results, fulvic acid primarily interacts with tryptophan residues in trypsin and induces alterations in their microenvironment. Three-dimensional fluorescence spectrum and circular dichroism further proves this conclusion. The molecular docking simulation reveals that the interaction between the two groups primarily arises from hydrogen bonding and van der Waals forces. The findings suggest that FA has the ability to induce conformational changes in trypsin's secondary structure.