No abstract

In this study, it was aimed to investigate characteristics and intracellular delivery of two different-sized PLGA nanoparticles in ouzo region by considering number of nanoparticles. To determine the effect of formulation parameters on average particle size, Dil labeled nanoparticles were prepared using a three-factor, two-level full factorial statistical experimental design. PLGA (230.8 ± 4.32 nm) and PLGA (157.9 ± 6.16 nm) nanoparticles were obtained by altering polymer amount based on experimental design results and characterized. Same number of PLGA and PLGA nanoparticles per cell were applied onto HEK293 cells; then, cytotoxicity, uptake kinetics and mechanism were evaluated by flow cytometry and fluorescent microscopy. Also same weight of PLGA and PLGA nanoparticles were applied and cellular uptake of these nanoparticles was evaluated. It was found that PLGA nanoparticles had higher encapsulation efficiency and slower dye release compared to PLGA nanoparticles. When they were applied at same counts per cell, PLGA nanoparticles displayed faster and higher intracellular dye transfer than PLGA nanoparticles. On the other hand, PLGA appeared to be a more effective vehicle than PLGA when applied at the same weight concentration. It was also shown that for both nanoparticles, HEK293 cells employed macropinocytic, caveolae- and clathrin-mediated endocytic pathways.

No abstract

Sleep inertia is a disabling state of grogginess and impaired vigilance immediately upon awakening. The adenosine receptor antagonist, caffeine, is widely used to reduce sleep inertia symptoms, yet the initial, most severe impairments are hardly alleviated by post-awakening caffeine intake. To ameliorate this disabling state more potently, we developed an innovative, delayed, pulsatile-release caffeine formulation targeting an efficacious dose briefly before planned awakening. We comprehensively tested this formulation in two separate studies. First, we established the in vivo caffeine release profile in 10 young men. Subsequently, we investigated in placebo-controlled, double-blind, cross-over fashion the formulation’s ability to improve sleep inertia in 22 sleep-restricted volunteers. Following oral administration of 160 mg caffeine at 22:30, we kept volunteers awake until 03:00, to increase sleep inertia symptoms upon scheduled awakening at 07:00. Immediately upon awakening, we quantified subjective state, psychomotor vigilance, cognitive performance, and followed the evolution of the cortisol awakening response. We also recorded standard polysomnography during nocturnal sleep and a 1-h nap opportunity at 08:00. Compared to placebo, the engineered caffeine formula accelerated the reaction time on the psychomotor vigilance task, increased positive and reduced negative affect scores, improved sleep inertia ratings, prolonged the cortisol awakening response, and delayed nap sleep latency one hour after scheduled awakening. Based on these findings, we conclude that this novel, pulsatile-release caffeine formulation facilitates the sleep-to-wake transition in sleep-restricted healthy adults. We propose that individuals suffering from disabling sleep inertia may benefit from this innovative approach.Trials registration: NCT04975360.