A low dose of curcumin-PDA nanoparticles improves viability and proliferation in endoneurial fibroblasts and Schwann cell cultures

Abstract

Abstract Curcumin is a polyphenol extracted from Curcuma longa’s roots. Low doses of curcumin are related to anti-inflammatory, antioxidant, and neuroprotective effects, while high doses are used for their lethality. This diversity of behaviors allows us to understand curcumin as a compound with hormetic action. Due to its strongly hydrophobic character, curcumin is often solubilized in organic compounds. Despite their importance in experimental design, the specific biological impact of these vehicles alone is rarely documented. In this way, we have recently reported the undesirable and occasionally irreversible effects of alcohol and DMSO on the viability of primary Schwann cell cultures. In this scenario, the use of nanoparticles as delivery systems has become a successful alternative strategy for these compounds. In the present work, we describe the structure of Polydopamine (PDA) nanoparticles, loaded with a low dose of curcumin (Curc-PDA) without the use of additional organic solvents, characterized by transmission/scanning electron microscopy, and diffraction light scattering. We analyzed the curcumin released using Ultra-High-Pressure-Liquid Chromatography with a Mass-Spectrometry detector, and we found two different forms of curcumin. Small increased cell viability and proliferation were observed in endoneurial fibroblast and Schwann cell primary cultures when Curc-PDA was steadily supplied for 5 days. Furthermore, opposite to that observed in front of organic solvents, PDA alone showed no effect over endoneurial fibroblast or Schwann cell viability nor proliferation. These results confirm the properties of curcumin at very low doses, thus widening its therapeutic window thanks to the increased bioavailability provided by our biological approach.