Production and characterization of bovine hoof membranes as standardized in vitro model for nail studies

Abstract

Several studies can be found using bovine hoof membranes as a nail in vitro model. Most of them are actually permeability studies, while it is very hard to find reference in literature related to the use of those membranes to evaluate safety and efficacy of products. In facts, some effects, both desirable or not, are not strongly related to the penetration of the products thru all of the nail plate keratin layers. There are morphological characteristics and properties such as mechanical ones which could be affected even by a product acting on the surface of the nail. Moreover, hoof membranes production is not a standardized procedure, as well as membranes characterization which is a critical step to deal with when we are looking for a specific in vitro model. In this work, hoof membranes production is described in detail, along with the characterization techniques and parameters chosen for studying the model, such as contact angle measurement and mechanical properties assessment. The production method developed in this work has shown to be effective, making it possible to obtain membranes with desirable thickness, homogenous morphology and suitable mechanical properties. Mechanical properties were the most challenging to be assessed, also for the poor coverage of the topic by scientific literature. In particular the mechanical assessment has never been used before with this specific aim thus this research could be considered as a feasibility protocol in order to obtain a suitable nail model for further studies concerning drug permeability or safety and efficacy of final products .

Keywords: Contact angle; Efficacy evaluation; Hoof membranes; Mechanical assessment; Nail model; Safety evaluation.