Nanoparticle mediated drug delivery of rolipram to tyrosine kinase B positive cells in the inner ear with targeting peptides and agonistic antibodies

Abstract

Aim: Systemic pharmacotherapies have limitation due to blood-labyrinth barrier, so local delivery via the round window membrane opens a path for effective treatment. Multifunctional nanoparticle (NP)-mediated cell specific drug delivery may enhance efficacy and reduce side effects. Different NPs with ligands to target TrkB receptor were tested. Distribution, uptake mechanisms, trafficking, and bioefficacy of drug release of rolipram loaded NPs were evaluated.Methods: We tested lipid based nanocapsules (LNCs), Quantum Dot, silica NPs with surface modification by peptides mimicking TrkB or TrkB activating antibodies. Bioefficacy of drug release was tested with rolipram loaded LNCs to prevent cisplatin-induced apoptosis. We established different cell culture models with SH-SY-5Y and inner ear derived cell lines and used neonatal and adult mouse explants. Uptake and trafficking was evaluated with FACS and confocal as well as transmission electron microscopy.Results: Plain NPs show some selectivity in uptake related to the in vitro system properties, carrier material, and NP size. Some peptide ligands provide enhanced targeted uptake to neuronal cells but failed to show this in cell cultures. Agonistic antibodies linked to silica NPs showed TrkB activation and enhanced binding to inner ear derived cells. Rolipram loaded LNCs proved as effective carriers to prevent cisplatin-induced apoptosis.Discussion: Most NPs with targeting ligands showed limited effects to enhance uptake. NP aggregation and unspecific binding may change uptake mechanisms and impair endocytosis by an overload of NPs. This may affect survival signaling. NPs with antibodies activate survival signaling and show effective binding to TrkB positive cells but needs further optimization for specific internalization. Bioefficiacy of rolipram release confirms LNCs as encouraging vectors for drug delivery of lipophilic agents to the inner ear with ideal release characteristics independent of endocytosis.

Brain-Derived Neurotrophin and TrkB in Head and Neck Squamous Cell Carcinoma

“…The Trk family of receptors includes the neurotrophin receptor tyrosine kinase-2 ( NTRK2 ) (TrkB) specific for brain-derived neurotrophic factor (BDNF) and neurotrophin-4 (NT-4) [5]. Both BDNF and TrkB are key factors in the development and maintenance of hearing function [6,7,8,9,10]. Brain-derived neurotrophic factor and its receptor moieties are instrumental to facilitate sensory neuronal survival in embryonic rat [11].…”

Organotypic Culture of Neonatal Murine Inner Ear Explants

“…We have described the fundamental procedures for dissecting, plating, and culturing early post-natal murine inner ear explants using Millicell culture inserts and serum- free conditions. The use of serum free media for cochlear and vestibular explant culture is becoming more common (Kopke et al, 1997; Cunningham et al, 2002; Amarjargal et al, 2009; Bas et al, 2014; Glueckert et al, 2015; Wu et al, 2018). And, published methods similar to this protocol further validate the efficacy of organotypic cell culture inserts when culturing cochlear or vestibular tissues (Praetorius et al, 2010; Baker and Staecker, 2012; Dammeyer et al, 2014; Defourny et al, 2015; Ma et al, 2017).…”

Cochlear protein biomarkers as potential sites for targeted inner ear drug delivery

“…As with the trisialoganglioside clostridial toxin receptor, phage display has been used to develop binding peptides for these receptors. Recent work has demonstrated that nanoparticles targeted with the TrkB binding A371 peptide bind preferentially to the spiral ganglion's neuronal cells [35], and that this targeting peptide has enabled Rolipram, a phosphodiesterase inhibitor, to be delivered to the mouse spiral ganglia as a potential agent that improves cell survival [35,45]. Additional work has suggested the possibility of targeted delivery of the TrkB agonist, 7,8-dihydroxyflavone (DHF) as a means for increasing neurite growth in the setting of kainicacid cochlear damage [46].…”