2 research outputs found
Analiza nakupovalnih centrov v Ljubljani s pomočjo atributivnega pristopa
Alginate
microgels are widely used as delivery systems in food,
cosmetics, and pharmaceutical industries for encapsulation and sustained
release of hydrophilic compounds and cells. However, the encapsulation
of lipophilic molecules inside these microgels remains a great challenge
because of the complex oil-core matrix required. The present study
describes an original two-step approach allowing the easy encapsulation
of several oil microdroplets within alginate microgels. In the first
step, stable oil microdroplets were formed by preparing an oil-in-water
(O/W) Pickering emulsion. To stabilize this emulsion, we used two
solid particles, namely the cotton cellulose nanocrystals (CNC) and
calcium carbonate (CaCO<sub>3</sub>). It was observed that the surface
of the oil microdroplets formed was totally covered by a CNC layer,
whereas CaCO<sub>3</sub> particles were adsorbed onto the cellulose
layer. This solid CNC shell efficiently stabilized the oil microdroplets,
preventing them from undesired coalescence. In the second step, oil
microdroplets resulting from the Pickering emulsion were encapsulated
within alginate microgels using microfluidics. Precisely, the outermost
layer of oil microdroplets composed of CaCO<sub>3</sub> particles
was used to initiate alginate gelation inside the microfluidic device,
following the internal gelation mode. The released Ca<sup>2+</sup> ions induced the gel formation through physical cross-linking with
alginate molecules. This innovative and easy to carry out two-step
approach was successfully developed to fabricate monodisperse alginate
microgels of 85 μm in diameter containing around 12 oil microdroplets
of 15 μm in diameter. These new oil-core alginate microgels
represent an attractive system for encapsulation of lipophilic compounds
such as vitamins, aroma compounds or anticancer drugs that could be
applied in various domains including food, cosmetics, and medical
applications
Glycosaminoglycan mimetics obtained by microwave-assisted sulfation of marine bacterium sourced infernan exopolysaccharide
International audienceSulfated glycosaminoglycans (GAGs) are fundamental constituents of both the cell surface and extracellular matrix. By playing a key role in cell-cell and cell-matri x interactions, GAGs are involved in many physiological and pathological processes. To design GAG mimetics with similar therapeutic potential as the natural ones, the specific structural features, among them sulfate content, sulfation pattern, and chain length, should be considered. In the present study, we describe a sulfation method based on microwave radiation to obtain highly sulfated derivatives as GAG mimetics. The starting low-molecular-weight (LMW) derivative was prepared from the infernan exopolysaccharide, a highly branched naturally slightly sulfated heteropolysaccharide synthesized by the deep-sea hydrothermal vent bacterium Alteromonas infernus. LMW highly sulfated infernan derivatives obtained by conventional heating sulfation have already been shown to display GAG-mimetic properties. Here, the potential of microwave-assisted sulfation versus that of the conventional method to obtain GAG mimetics was explored. Structural analysis by NMR revealed that highly sulfated derivatives from the two methods shared similar structural features, emphasizing that microwave-assisted sulfation with a 12-fold shorter reaction time is as efficient as the classical one