Investigation of drug release modulation from poly(2-oxazoline) micelles through ultrasound

Abstract

Among external stimuli used to trigger release of a drug from a polymeric carrier, ultrasound has gained increasing attention due to its non-invasive nature, safety and low cost. Despite this attention, there is only limited knowledge about how materials available for the preparation of drug carriers respond to ultrasound. This study investigates the effect of ultrasound on the release of a hydrophobic drug, dexamethasone, from poly(2-oxazoline)-based micelles. Spontaneous and ultrasound-mediated release of dexamethasone from five types of micelles made of poly(2-oxazoline) block copolymers, composed of hydrophilic poly(2-methyl-2-oxazoline) and hydrophobic poly(2-n-propyl-2-oxazoline) or poly(2-butyl-2-oxazoline-co-2-(3-butenyl)-2-oxazoline), was studied. The release profiles were fitted by zero-order and Ritger-Peppas models. The ultrasound increased the amount of released dexamethasone by 6% to 105% depending on the type of copolymer, the amount of loaded dexamethasone, and the stimulation time point. This study investigates for the first time the interaction between different poly(2-oxazoline)-based micelle formulations and ultrasound waves, quantifying the efficacy of such stimulation in modulating dexamethasone release from these nanocarriers.

Synthesis and Characterization of cryogel microcarriers for sustained local delivery of anticancer therapeutics to Glioblastoma multiforme

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Poly(2‐oxazoline)‐ and Poly(2‐oxazine)‐Based Self‐Assemblies, Polyplexes, and Drug Nanoformulations—An Update

“…Salgarella, Zahoranová et al. studied encapsulation of anti‐inflammatory drug dexamethasone (DEXA) into five different diblock and triblock copoly(2‐oxazoline)s. [ 160 ] Depending on the polymer structure, they observed formation of small micelles (diameter 35 nm), but also larger aggregates (hundreds of nm—several microns). The loading capacity ranged between 4.2 wt% (solubilization 0.44 g L −1 ) in case of copolymer p(EnOx‐BuOx) stat ‐ b ‐pMeOx to 14.7 wt% (solubilization 1.72 g L −1 ) in case of diblock copolymer pPrOx‐ b ‐pMeOx.…”

Stimuli-Responsive Drug Release from Smart Polymers

“…Increasing the number of pulses improved the animal survival rate compared to a single burst of LIFU; an increase in vascular permeability of tumors was additionally observed [24]. Salgarella et al investigated the synthesis and evaluation of five different forms of poly(2-oxazoline) micelles for a possible carrier of a drug delivery system triggered with ultrasound [25]. Micelles were tailored by controlling the ratio of hydrophilic and hydrophobic block copolymers and exhibited a significant release of dexamethasone.…”