Antibody-Functionalized Carnauba Wax Nanoparticles to Target Breast Cancer Cells

[Image: see text] Development of safer nanomedicines for drug delivery applications requires immense efforts to improve clinical outcomes. Targeting a specific cell, biocompatibility and biodegradability are vital properties of a nanoparticle to fulfill the safety criteria in medical applications. Herein, we fabricate antibody-functionalized carnauba wax nanoparticles encapsulated a hydrophobic drug mimetic, which is potentially interesting for clinical use due to the inert and nontoxic properties of natural waxes. The nanoparticles are synthesized applying miniemulsion methods by solidifying molten wax droplets and further evaporating the solvent from the dispersion. The pH-selective adsorption of antibodies (IgG1, immunoglobulin G1, and CD340, an antihuman HER2 antibody) onto the nanoparticle surface is performed for practical and effective functionalization, which assists to overcome the complexity in chemical modification of carnauba wax. The adsorption behavior of the antibodies is studied using isothermal titration calorimetry (ITC), which gives thermodynamic parameters including the enthalpy, association constant, and stoichiometry of the functionalization process. Both antibodies exhibit strong binding at pH 2.7. The CD340-decorated wax nanoparticles show specific cell interaction toward BT474 breast cancer cells and retain the targeting function even after 6 months of storage period.