Nanoferrite Embedded Magnetocochleate Microstructures to Encapsulate Insulin Macromolecules

Abstract

A fused lipid microstructure embedded with ferrite nanoparticles, a magnetocochleate, was prepared and used to encapsulate insulin by making use of: the lipid phase transition from the fluidic lamellar phase to the gel phase at pH 2. The magnetocochleate obtained by tuning the hydrophilic headgroup hydration of phosphatidylserine in the presence of ferrite encapsulates a larger amount of insulin. Enhanced encapsulation of insulin in between the fused lipid bilayer indicates that the magnetocochleate has potential as a delivery vehicle for an active pharmaceutical incipient. In particular, protein macromolecules like insulin are target incipients, because these fused microstructures protect insulin from the action of enzymes and from pH changes, which is necessary to maintain its bioactivity. Microscopic and spectroscopic investigations of these fused microstructures were done to understand the internal microstructure and encapsulation of protein. Freeze fracture transmission electron microscopy revealed the gel-like phase of fused lipid bilayers and the presence of ferrite in magnetocochleate. Confocal micro-Raman, high performance liquid chromatography (HPLC) studies confirmed the presence of ferrite and insulin within the lipid microstructures. Differential scanning calorimetry (DSC) and Fourier transform infrared resonance (FTIR) Studies Substantiate the state of lipid in these fused microstructures. In vivo subcutaneous activity was studied in a tat model, and the positive result obtained there signifies the promising potential of magnetocochleates in subcutaneous delivery of macromolecules.