Controlled release of folic acid through liquid-crystalline folate nanoparticles

Nanoparticle formulation having ability to control the release of protein for drug delivery application

Controlled release of therapeutic protein is desirable for protein delivery applications. This study discuss about a unique nanomaterial which is capable to provide the protein release in controlled manner. The nanomaterial has been synthesized from folic acid molecules and bovine serum albumin (BSA¹) is loaded in these nanoparticles as a model protein. The size distribution of the synthesized folic acid nanoparticles was observed between 200 and 300nm. The release study using high performance liquid chromatography suggests that more than 90% of BSA can be encapsulated in the nanoparticles having BSA loaded up to 19.29mg (57% of folic acid loaded). Release study also reveals that more than 95% of the total folic acid and BSA were released in phosphate buffer saline solution within 48h. Investigation of folic acid release along with BSA release reveals that the particles are formed through folic acid-protein complex. Salt concentration in the release medium and crosslinked cations in the nanoparticles are found to be the key parameters to control the release rate. Thus, folic acid nanoparticles are efficient carrier for protein encapsulation and release in the controlled manner with minimum drug loss.

An investigation of folic acid-protein association sites and the effect of this association on folic acid self-assembly

The contribution of folic acid (FA)-tryptophan interactions to FA-protein association was investigated in the context of using FA as a drug carrier in protein delivery systems. Bovine serum albumin (BSA) and indolicidin were used as model proteins in the study. The FA-BSA complex was characterized by using the Bradford reagent to identify the impact of FA-BSA association on BSA-dye reagent interactions. UV-visible spectroscopic analysis of the FA-BSA mixture showed that the absorbance maximum of BSA-dye reagent occurred at 595 nm, even after the association of FA with BSA. This confirms that protonated amino acid groups of the protein are not involved in FA-BSA association. Moreover, molecular dynamics (MD) simulation confirmed the presence of an associative interaction between aromatic moieties in FA and tryptophan moieties in the indolicidin molecule, which disrupted FA self-assembly. An X-ray diffraction (XRD) study showed that there was limited disruption of FA self-assembly after the addition of BSA or tryptophan. This suggests that FA and BSA are compatible and associate with each other. Graphical Abstract Mechanism of folic acid and protein association.