Oil/water nano-emulsion loaded with cobalt ferrite oxide nanocubes for photo-acoustic and magnetic resonance dual imaging in cancer: in vitro and preclinical studies.

Dual imaging dramatically improves detection and early diagnosis of cancer. In this work we present an oil in water (O/W) nano-emulsion stabilized with lecithin and loaded with cobalt ferrite oxide (Co0.5Fe2.5O4) nanocubes for photo-acoustic and magnetic resonance dual imaging. The nanocarrier is responsive in in vitro photo-acoustic and magnetic resonance imaging (MRI) tests. A clear and significant time-dependent accumulation in tumor tissue is shown in in vivo photo-acoustic studies on a murine melanoma xenograft model. The proposed O/W nano-emulsion exhibits also high values of r2/r1 (ranging from 45 to 85, depending on the magnetic field) suggesting a possible use as T2 weighted image contrast agents. In addition, viability and cellular uptake studies show no significant cytotoxicity on the fibroblast cell line. We also tested the O/W nano-emulsion loaded with curcumin against melanoma cancer cells demonstrating a significant cytotoxicity and thus showing possible therapeutic effects in addition to the in vivo imaging.

Bioinspired Oil Core/Silica Shell Nanocarriers with Tunable and Multimodal Functionalities.

The application of multimodal systems in the field of nanomedicine is advantageous as they can perform two or more tasks simultaneously. Here a robust approach is presented mimicking biogenic silica to design a multilayered nanocarrier system with a central oil core encapsulated within a polymer-silica shell. The outermost silica shell has been deposited through a biosilicification process induced by poly-L-lysine molecules immobilized on the surface of emulsion droplets. This system can be simultaneously loaded with high amount of hydrophobic molecules or contrasting agents in the inner oil core, while the polymeric-silica layers can be easily tagged with at least two different contrasting agents. Additionally, the zwitterionic nature of the silica precipitating peptide (poly-L-lysine) has been efficiently exploited to modulate and entirely reverse the surface charge of the nanocarrier without using any additional coating material. It has been demonstrated experimentally that the designed nanocapsular system is monodisperse, nontoxic, cargo protective, tunable in thickness, fluorescent, and magnetic resonance imaging (MRI) active so highly versatile for multiple applications in the field of drug delivery and in vivo imaging.