Chemiluminescent solid lipid nanoparticles (SLN) and interations with intact skin

Jennifer Breidenich, Julia Patrone, Lisa Kelly, Jason Benkoski, Huong Le, Jennifer Sample The Johns Hopkins University Applied Ph ysics Laboratory, 11100 Johns Hopkins Rd., Laurel, MD ABSTRACT We report the synthesi s and characterization of a novel nanoparticle formulation designed for skin penetration for the purpose of skin imaging. Solid lipid nanoparticles (SLNs), a drug delivery vehicle, were used as the matrix for targeted delivery of peroxide-sensitive chemiluminescent compounds to the epidermis. Luminol and oxalate were chosen as the chemiluminescent test systems, and a form ulation was determined based upon non-toxic components, lotion-like properties, and longevity / visibility of a chemiluminescent signal. The luminescence lifetime was extended in the lipid formulation in comparison to the chemiluminescent system in solution. When applied to porcine skin, our formulation remained detectable relative to negative and positive controls. Initial MTT toxicity testing using HepG2 cells have indicated that this formulation is relatively non-toxic. This formulation could be used to image nativ e peroxides present in tissue that may be indicative of skin disease. 1. INTRODUCTION The utilization of nanomaterials for biosensing app lications has great potential for early disease detection. Overproduction of hydrogen peroxide occurs in the development of many diseases, including the damage caused to skin by exposure to ul traviolet radiation. Thus, the sensitive detection of low levels of hydrogen peroxide in skin could serve as an early warning indicator for skin cancer. In addition, hydrogen peroxide has been found to be involved in wound healing,