Micellar solubilization of Lavender oil in aqueous P85/P123 systems: Investigating the associated micellar structural transitions, therapeutic properties and existence of double cloud points

Abstract

Importance of pluronic P85 as carrier for drugs arises due to its ability to sensitize cell membranes for delivery of drugs across multi drug resistant cancer cells and blood brain barrier. It is thus necessary to understand how lipophilic drugs and phytochemicals influence its self-assembly characteristics and how the therapeutic properties of these lipophiles are modulated upon encapsulation in P85 micelles. We have investigated solubilization characteristics of Lavender essential oil (LO) in P85 and P85-P123 micellar systems and studied the associated structural and therapeutic properties by DLS, SANS, viscosity, ITC, antimicrobial and in vitro cancer cell viability studies. We observed that LO induces micellar structural transitions in aqueous P85 and P85-P123 systems leading to the formations of worm like micelles and vesicles. LO solubilized systems exhibit anticancer and antimicrobial properties, and show existence of double cloud points namely, upper and lower cloud points (UCP & LCP). A spherical-to-elliptical micellar structural transition is observed in these LO solubilized systems upon cooling down to LCP, which is unusual and not reported hitherto in aqueous pluronic systems. The observed results show how essential oils can influence the self-assembly characteristics of P85 based micellar systems and how their therapeutic properties are manifested under micellar encapsulation.