Nanocarriers, and especially nanostructured lipid carriers (NLC), represent one of the most effective systems for topical drug administration. NLCs are biodegradable, biocompatible and provide a prolonged drug release. The glutamate release inhibitor Riluzole (RLZ) is a drug currently used for amyotrophic lateral sclerosis (ALS), with anti-proliferative effects potentially beneficial for diseases with excessive cell turnover. However, RLZ possesses low water solubility and high light-sensibility. We present here optimized NLCs loaded with RLZ (RLZ-NLCs) as a potential topical treatment. RLZ-NLCs were prepared by the hot-pressure homogenization method using active essential oils as liquid lipids, and optimized using the design of experiments approach. RLZ-NLCs were developed obtaining optimal properties for dermal application (mean size below 200 nm, negative surface charge and high RLZ entrapment efficacy). In vitro release study demonstrates that RLZ-NLCs allow the successful delivery of RLZ in a sustained manner. Moreover, RLZ-NLCs are not angiogenic and are able to inhibit keratinocyte cell proliferation. Hence, a NLCs delivery system loading RLZ in combination with natural essential oils constitutes a promising strategy against keratinocyte hyperproliferative conditions.

Cancer is identified as one of the main causes of death worldwide, and an effective treatment that can reduce/eliminate serious adverse effects is still an unmet medical need. Diclofenac, a non-steroidal anti-inflammatory drug (NSAID), has demonstrated promising antitumoral properties. However, the prolonged use of this NSAID poses several adverse effects. These can be overcome by the use of suitable delivery systems that are able to provide a controlled delivery of the payload. In this study, Diclofenac was incorporated into biodegradable polymeric nanoparticles based on PLGA and the formulation was optimized using a factorial design approach. A monodisperse nanoparticle population was obtained with a mean size of ca. 150 nm and negative surface charge. The release profile of diclofenac from the optimal formulation followed a prolonged release kinetics. Diclofenac nanoparticles demonstrated antitumoral and antiangiogenic properties without causing cytotoxicity to non-tumoral cells, and can be pointed out as a safe, promising and innovative nanoparticle-based formulation with potential antitumoral effects.

Background: Motor neuron diseases are neurological disorders characterized by progressive degeneration of upper and/or lower motor neurons. Amyotrophic Lateral Sclerosis (ALS) is the most common form of motor neuron diseases, where patients suffer progressive paralysis, muscle atrophy and finally death. Despite ALS severity, no treatment is safe and fully effective. In this area, Riluzole was the first drug approved and it constitutes the gold-standard for this pathology. However, to obtain suitable therapeutic efficacy, Riluzole requires high doses that are associated with severe adverse effects in other tissues. To attain Riluzole therapeutic efficacy avoiding other organs side-effects, new therapeutic strategies to enhance the delivery of Riluzole specifically to motor neurons constitute an unmet medical need. In this area, we have developed a novel multifunctional nanostructurated carrier to selectively deliver Riluzole to motor neurons. Results: This work develops and characterizes at in vitro and in vivo levels a tissue-targeted formulation of peptide and PEG-labelled PLGA nanoparticles encapsulating Riluzole. For this purpose, pVEC, a cell penetrating peptide able to increase transport through the blood–brain barrier, was attached to the nanoparticles surface. The multifunctionalized nanoparticles show suitable characteristics for the release of Riluzole in the central nervous system and were detected in motor neurons within 1 h after administration while significantly reducing the concentration of Riluzole in non-therapeutic organs responsible of side effects. Conclusion: A novel drug delivery system has been developed and characterized, demonstrating enhanced CNS biodistribution of riluzole, which shows promise as efficient therapeutic tool for motor neuron diseases, including amyotrophic lateral sclerosis.