Thermoresponsive Hydrogel Containing Viscum album Extract for Topic and Transdermal Use: Development, Stability and Cytotoxicity Activity.

Viscum album L. (Santalaceae), also known as European mistletoe, is a semi-parasitic plant that grows on different host trees. Our group recently demonstrated the antitumoral activity of ethanolic V. album extracts in vitro, depending on the dose and the host tree, V. album ssp abietis from Abies alba being the most active extract. The goal of this work focused on the development of a new topical formulation containing V. album extracts, evaluation of in vitro toxicity and ex vivo skin permeation assays. The Poloxamer 407 hydrogel containing 5% of dry (VA_DEH) or aqueous (VA_AEH) extract presented dermal compatible pH and microbiological stability for 180 days. The hydrogels flow curve presented a non-linear relation, characteristic of non-Newtonian fluids, and the mean viscosity for the VA_DEH and VA_AEH was 372.5 ± 7.78 and 331.0 ± 2.83 Pa.s, respectively, being statistically different (Welch's t test; p < 0.01). Additionally, WST-1 in vitro assays revealed a dose-dependent toxicity for both formulations and VA_DEH presented a higher activity than the VA_AEH. The promising cytotoxic potential of VA_DEH lead to the ex vivo skin permeation assay with 2.73 ± 0.19 µg/cm2 of chlorogenic acid, which permeated at 8 h, showing a transdermal potential. These in vitro results support the idea that VA_DEH is a novel promising candidate for mistletoe therapy. Therefore, further in vivo and pre-clinical experiments should be performed to evaluate the safety and efficacy of this new dermic delivery system.

Metallosis: A diagnosis not only in patients with metal-on-metal prostheses.

Although the real actual incidence of metallosis is unknown, it is described as a rare diagnosis with a 5% estimated incidence in the hip prosthetic replacements. The adoption of non-metallic articular prosthetic devices, made of polyethylene and ceramic, is the main reason to the diminishing number of reported cases. We present a case of metallosis with a clinical systemic presentation in a patient with a non-metallic hip prosthesis, which occurred due to a fracture of the acetabular liner component, leading to abnormal metal-metal contact. The metallic debris leads to a massive local and systemic release of cytokines. Revision is necessary whenever osteolysis and loosening of the prosthesis occur. Imaging evaluation, especially CT, has a central role in diagnosis and planning the surgical treatment.