Know more

Our use of cookies

Cookies are a set of data stored on a user’s device when the user browses a web site. The data is in a file containing an ID number, the name of the server which deposited it and, in some cases, an expiry date. We use cookies to record information about your visit, language of preference, and other parameters on the site in order to optimise your next visit and make the site even more useful to you.

To improve your experience, we use cookies to store certain browsing information and provide secure navigation, and to collect statistics with a view to improve the site’s features. For a complete list of the cookies we use, download “Ghostery”, a free plug-in for browsers which can detect, and, in some cases, block cookies.

Ghostery is available here for free: https://www.ghostery.com/fr/products/

You can also visit the CNIL web site for instructions on how to configure your browser to manage cookie storage on your device.

In the case of third-party advertising cookies, you can also visit the following site: http://www.youronlinechoices.com/fr/controler-ses-cookies/, offered by digital advertising professionals within the European Digital Advertising Alliance (EDAA). From the site, you can deny or accept the cookies used by advertising professionals who are members.

It is also possible to block certain third-party cookies directly via publishers:

Cookie type

Means of blocking

Analytical and performance cookies

Realytics
Google Analytics
Spoteffects
Optimizely

Targeted advertising cookies

DoubleClick
Mediarithmics

The following types of cookies may be used on our websites:

Mandatory cookies

Functional cookies

Social media and advertising cookies

These cookies are needed to ensure the proper functioning of the site and cannot be disabled. They help ensure a secure connection and the basic availability of our website.

These cookies allow us to analyse site use in order to measure and optimise performance. They allow us to store your sign-in information and display the different components of our website in a more coherent way.

These cookies are used by advertising agencies such as Google and by social media sites such as LinkedIn and Facebook. Among other things, they allow pages to be shared on social media, the posting of comments, and the publication (on our site or elsewhere) of ads that reflect your centres of interest.

Our EZPublish content management system (CMS) uses CAS and PHP session cookies and the New Relic cookie for monitoring purposes (IP, response times).

These cookies are deleted at the end of the browsing session (when you log off or close your browser window)

Our EZPublish content management system (CMS) uses the XiTi cookie to measure traffic. Our service provider is AT Internet. This company stores data (IPs, date and time of access, length of the visit and pages viewed) for six months.

Our EZPublish content management system (CMS) does not use this type of cookie.

For more information about the cookies we use, contact INRA’s Data Protection Officer by email at cil-dpo@inra.fr or by post at:

INRA
24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

Menu Logo Principal Logo BIA

Home page

Encapsulation of Pickering oil microdroplets into alginate microgels by microfluidics for lipophilic compound delivery

microgels
© INRA
Alginate microgels are widely used as delivery systems in food, cosmetics and the pharmaceutical industries for the encapsulation and sustained release of hydrophilic compounds and cells.

However, the encapsulation of several lipophilic molecules within a unique microgel remains a major challenge. Indeed, to date, only the encapsulation of one oil droplet in a hydrogel capsule has been demonstrated and uses surfactants that are globally undesired in formulations. Our objective is therefore to propose new biosourced and surfactant-free microgels of micrometric size containing highly stable oil microdroplets for the encapsulation and the controlled release of lipophilic active compounds. Our study describes an original two-step approach in which microfluidics allows the encapsulation of lipophilic multicores in a perfectly controlled size and composition. The first step consists in forming a stock of oil microdroplets via an oil-in-water (O/W) Pickering emulsion stabilised by hybrid particles made of cellulose nanocrystals and calcium carbonate (CaCO3). Pickering emulsions that use biosourced particles irreversibly adsorbed at the interface are an alternative solution to surfactants for stabilising oil microdroplets. In the second step, the resulting oil microdroplets are encapsulated using microfluidics into alginate-based microgels. By diffusion of acetic acid into the microdroplets of alginate, the CaCO3 adsorbed on the CNCs is solubilised, inducing the alginate gelation. This demonstrates the double action of the hybrid as an interface stabiliser and gelling agent for the encapsulation of the oil microdroplets in hydrogels. This innovative approach shows the possibility of generating monodisperse alginate microgels (85 μm in diameter) containing about 12 oil microdroplets (15 μm in diameter). For the first time, the microfluidic control associated with the stability of Pickering emulsions has led to new oil multicores in microgels. Moreover, the potential of this multicore lipophilic approach was confirmed by the efficient encapsulation of a model lipophilic compound (Red Nile). Our microgels remain stable for several months, suggesting excellent storage characteristics. In addition, controlled release results confirmed, on the one hand, the stability of the CNC shell at the O-W interface of independent oil droplets after the alginate degradation and, on the other hand, the lipophilic compound release in the medium using suitable solvents. These microgels have high potential for compartmentalised and simultaneous encapsulation of lipophilic and/or hydrophilic compounds such as vitamins, aromatics or anti-cancer drugs in a single microgel.

Publications :

M. Marquis, V. Alix, I. Capron, S. Cuenot, A. Zykwinska. Microfluidic encapsulation of Pickering oil microdroplets into alginate microgels for lipophilic compound delivery. ACS Biomaterials Science & Engineering (2016), 2, 535-543, 2016. https://doi.org/10.1021/acsbiomaterials.5b00522