Publications by authors named "Albert Poortinga"

Nanoparticles have proven to be attractive carriers in therapeutic drug delivery since they can encapsulate, protect and stabilize a plethora of different drugs, thereby improving therapeutic efficacy and reducing side effects. However, specific targeting of drug-loaded nanoparticles to the tissue of interest and a timely and spatially controlled release of drugs on demand still represent a challenge. Recently, gas-filled microparticles, so-called antibubbles, have been developed which can efficiently encapsulate liquid drug droplets.

View Article and Find Full Text PDF

Antibubbles are liquid droplets encapsulated by a gas film that have recently been explored for on-demand ultrasound-triggered drug release. However, their ultrasound imaging capabilities are limited by their stiff shells stabilized with silica nanoparticles. Here, we develop polymeric antibubbles that generate greater ultrasound contrast than silica-based antibubbles, while showing better stability than conventional polymeric microbubbles.

View Article and Find Full Text PDF

Developing carriers capable of efficiently transporting both hydrophilic and lipophilic payloads is a captivating focus within the pharmaceutical and drug delivery research domain. Antibubbles, constituting an innovative encapsulation system designed for drug delivery purposes, have garnered scientific interest thanks to their distinctive water-in-air-in-water (W/A/W) structure. However, in contrast to their precursor, i.

View Article and Find Full Text PDF

Sonochemistry, although established in various fields, is still an emerging field finding new effects of ultrasound on chemical systems and are of particular interest for the biomedical field. This interdisciplinary area of research explores the use of acoustic waves with frequencies ranging from 20 kHz to 1 MHz to induce physical and chemical changes. By subjecting liquids to ultrasonic waves, sonochemistry has demonstrated the ability to accelerate reaction rates, alter chemical reaction pathways, and change physical properties of the system while operating under mild reaction conditions.

View Article and Find Full Text PDF

Hypothesis: Hydrophobized fumed silica particles were previously reported for producing antibubbles that are quite stable in neutral as well as in acidic media. To produce acid-responsive antibubbles (e.g.

View Article and Find Full Text PDF

The benefits of ultrasound are its ease-of-use and its ability to precisely deliver energy in opaque and complex media. However, most materials responsive to ultrasound show a weak response, requiring the use of high powers, which are associated with undesirable streaming, cavitation, or temperature rise. These effects hinder response control and may even cause damage to the medium where the ultrasound is applied.

View Article and Find Full Text PDF

Nebulization of mRNA therapeutics can be used to directly target the respiratory tract. A promising prospect is that mucosal administration of lipid nanoparticle (LNP)-based mRNA vaccines may lead to a more efficient protection against respiratory viruses. However, the nebulization process can rupture the LNP vehicles and degrade the mRNA molecules inside.

View Article and Find Full Text PDF
Article Synopsis
  • Microcapsules with liquid interiors and solid nanoparticle shells are used in various fields like food and pharmaceuticals for controlled release and biocompatibility.
  • Creating these microcapsules efficiently at a large scale has been tough due to issues with existing manufacturing methods, but new jetting techniques have shown promise.
  • The new method allows for the continuous production of microcapsules with unique properties, such as air-coated capsules that can release their contents quickly when stimulated, enhancing their application potential.
View Article and Find Full Text PDF

Antibubbles are unusual physical objects consisting of a liquid core(s) surrounded by a thin air film/shell while in a bulk liquid. Antibubbles carry two air-liquid interfaces, i.e.

View Article and Find Full Text PDF

The aim of this study was to develop high load-capacity antibubbles that can be visualized using diagnostic ultrasound and the encapsulated drug can be released and delivered using clinically translatable ultrasound. The antibubbles were developed by optimising a silica nanoparticle stabilised double emulsion template. We produced an emulsion with a mean size diameter of 4.

View Article and Find Full Text PDF

Micrometer-sized double emulsions and antibubbles were produced and stabilized via the Pickering mechanism by colloidal interfacial layers of polymeric nanoparticles (NPs). Two types of nanoparticles, consisting either of polylactic acid (PLA) or polylactic--glycolic acid (PLGA), were synthesized by the antisolvent technique without requiring any surfactant. PLA nanoparticles were able to stabilize water-in-oil (W/O) emulsions only after tuning the hydrophobicity by means of a thermal treatment.

View Article and Find Full Text PDF

Purpose: An antibubble is an encapsulated gas bubble with an incompressible inclusion inside the gas phase. Current-generation ultrasound contrast agents are bubble-based: they contain encapsulated gas bubbles with no inclusions. The objective of this work is to determine the linear and nonlinear responses of an antibubble contrast agent in comparison to two bubble-based ultrasound contrast agents, that is, reference bubbles and SonoVue .

View Article and Find Full Text PDF

We report the preparation of antibubbles by microfluidic methods. More specifically, we demonstrate a two-step approach, wherein a monodisperse water-in-oil-in-water (W/O/W) emulsion of core-shell construction is first generated via microfluidics and freeze-dried thereafter to yield, upon subsequent reconstitution, an aqueous dispersion of antibubbles. Stable antibubbles are attained by stabilization of the air-water interfaces through a combination of adsorbed particles and polymeric surfactant.

View Article and Find Full Text PDF

Antibubbles, which are liquid droplets surrounded by a thin shell of gas in a liquid phase, have several promising applications, among which is encapsulation. A major hurdle toward these applications has hitherto been the inherent instability of antibubbles, leading to lifetimes of at most minutes. Here we show the production of antibubbles with a lifetime of at least tens of hours, with their stability stemming from the adsorption of colloidal particles at gas-water interfaces.

View Article and Find Full Text PDF

We report a new way of producing microcapsules consisting of a shell of aggregated colloids (also referred to as colloidosomes) using aqueous phase-separated polymer solutions (water-in-water emulsions) as a template. The extremely low interfacial tension of the template allows the production of reversible colloidosomes that spontaneously disintegrate depending on environmental conditions, making them ideal for controlled release purposes. Also, colloidosomes can have an elongated shape such that they may be used as microfluidic membranes or artificial arteries.

View Article and Find Full Text PDF