No abstract

While drug‐eluting stents containing anti‐proliferative agents inhibit proliferation of smooth muscle cells (SMCs), they also delay the regrowth of the endothelial cells which can result in subsequent development of restenosis. Acidic extracellular environments promote cell anchorage and migration by inducing conformational change in integrins, the main cell adhesion proteins. This study addresses the feasibility of a citric acid (CA) functionalized nitinol stent for improving vascular biocompatibility, specifically enhancing endothelialization. CA functionalized nitinol vascular stents are compared to commercial bare metal (Zilver Flex) and paclitaxel eluting stents (Zilver PTX) in terms of re‐endothelialization. To study the effect of stent coatings, a stent conditioned media methodology was developed in an attempt to represent in vivo conditions. Overall, distinct advantages of the CA functionalized nitinol stent over commercial Zilver PTX DES and Zilver Flex BMS stents in terms of endothelial cell adhesion, migration, and proliferation are reported. These novel findings indicate the potential of a CA functionalized stent to serve as a bioactive and therapeutic surface for re‐endothelialization, perhaps in combination with a SMC proliferation inhibitor coating, to prevent restenosis.

No abstract

Antihistamines are capable of blocking mediator responses in allergic reactions including allergic rhinitis and dermatological reactions. By incorporating various H 1 receptor antagonists into a lipid cubic phase network, these active ingredients can be delivered locally over an extended period of time owing to the mucoadhesive nature of the system. Local delivery can avoid inducing unwanted side effects, often observed after systematic delivery. Lipid-based antihistamine delivery systems are shown here to exhibit prolonged release capabilities. In vitro drug dissolution studies investigated the extent and release rate of two model first-generation and two model second-generation H 1 antagonist antihistamine drugs from two monoacyglycerol-derived lipid models. To optimize the formulation approach, the systems were characterized macroscopically and microscopically by small-angle X-ray scattering and polarized light to ascertain the mesophase accessed upon an incorporation of antihistamines of varying solubilities and size. The impact of encapsulating the antihistamine molecules on the degree of mucoadhesivity of the lipid cubic systems was investigated using multiparametric surface plasmon resonance. With the ultimate goal of developing therapies for the treatment of allergic reactions, the ability of the formulations to inhibit mediator release utilizing RBL-2H3 mast cells with the propensity to release histamine upon induction was explored, demonstrating no interference from the lipid excipient on the effectiveness of the antihistamine molecules.