Improving the visualization of fluorescently tagged nanoparticles and fluorophore-labeled molecular probes by treatment with CuSO4 to quench autofluorescence in the rat inner ear

Targeted delivery of Tet1 peptide functionalized polymersomes to the rat cochlear nerve

“…8 Briefly, for transtympanic injection, 40 µL of each PM type was injected into the middle ear cavity; for cochleostomy, an osmotic pump filled with 100 µL of PMs (the PMs were diluted 1:1 with artificial perilymph) was connected to the scala tympani (ST) (via a hole in the bony labyrinth that was made with a 0.5 mm diameter burr) by a polyethylene tube prefilled with the same solution ( Figure 1B). The analysis was carried out blind, the PMs were coded prior to administration, and evaluation of the tissue by confocal microscopy was completed before decoding.…”

“…In our previous study, unlabelled PMs that were delivered onto the round window membrane (RWM) did not appear in SGCs and spiral ganglion satellite cells. 8 In the present study, PMs were functionalized with the Tet1 peptide. The targetability was evaluated using two therapeutic approaches in which the PMs were delivered via either transtympanic injection or cochleostomy.…”

Comparison of the distribution pattern of PEG-b-PCL polymersomes delivered into the rat inner ear via different methods

“…PMs are vesiclelike nanoparticles formed from synthetic amphiphilic block copolymers such as poly(e-caprolactone)-blockpoly(ethylene glycol) (PEG-b-PCL) [1]. PMs have been previously investigated as delivery vehicles of therapeutic agents to the inner ear [2][3][4]. In in vitro cultures, the uptake of PMs into spiral ganglion neurons and glial cells was observed after periods of 24 h with no indication of toxicity [3].…”

“…We have previously reported that PEG-b-PCL PMs delivered by transtympanic injection passed the middle-inner ear barriers and were distributed within the cochlea and vestibulum [2]. As investigations have begun to elucidate the mechanisms and pharmacokinetics of the topical application of medication destined for the inner ear, newer strategies of delivery of therapeutics directly to the inner ear are beginning to emerge.…”

Recent advances in local drug delivery to the inner ear

“…Osmotic pumps have been used to test therapies for many 351 inner ear disorders and have been reviewed elsewhere (Swan et al, 2008, Pararas et al, 352 2012). This device was also employed to evaluate the biodistribution of nanocarriersin the 353 cochlea such as liposomes after transtympanic injection (Zou et al, 2014) or polymersomes 354 (Zhang et al, 2010 after direct infusion into the cochlea. The versatility 355 and ease of use of osmotic pumps in rodents make them very attractive for the study of 356 novel therapies applied to the inner ear.…”