3 research outputs found
Singularity of quantitative research: from collecting information to producing results
International audienc
Multifunctional Compartmentalized Capsules with a Hierarchical Organization from the Nano to the Macro Scales
Inspired by the cellsâ structure,
we present compartmentalized
capsules with temperature and magnetic-based responsiveness and hierarchical
organization ranging from the nano- to the visible scales. Liquefied
alginate macroscopic beads coated with a layer-by-layer (LbL) chitosan/alginate
shell served as containers both for model fluorophores and microcapsules,
which in their turn encapsulated either another fluorophore or magnetic
nanoparticles (MNPs). The microcapsules were coated with a temperature-responsive
chitosan/elastin-like recombinamer (ELR) nanostructured shell. By
varying the temperature from 25 to 37 °C, the two-hour release
of rhodamine encapsulated within the microcapsules and its diffusion
through the external compartment decreased from 84% and 71%. The devices
could withstand handling and centrifugal stress, with 50% remaining
intact at a rotation speed of 2000<i>g</i>. MNPs attributed
magnetic responsiveness toward external magnetic fields. Such a customizable
system can be envisaged to transport bioactive agents and cells in
tissue engineering applications
Layer-by-Layer Film Growth Using Polysaccharides and Recombinant Polypeptides: A Combinatorial Approach
Nanostructured films consisting of
polysaccharides and elastin-like
recombinamers (ELRs) are fabricated in a layer-by-layer manner. A
quartz-crystal microbalance with dissipation monitoring (QCM-D) is
used to follow the buildup of hybrid films containing one polysaccharide
(chitosan or alginate) and one of several ELRs that differ in terms
of amino acid content, length, and biofunctionality <i>in situ</i> at pH 4.0 and pH 5.5. The charge density of the ingredients at each
pH is determined by measuring their ζ-potential, and the thickness
of a total of 36 different films containing five bilayers is estimated
using the Voigt-based viscoelastic model. A comparison of the values
obtained reveals that thicker films can be obtained when working at
a pH close to the acidity constant of the polysaccharide used (near-p<i>K</i><sub>a</sub> conditions), suggesting that the construction
of such films is more favorable when based on the presence of hydrophobic
interactions between ELRs and partially neutralized polysaccharides.
Further analysis shows that the molecular weight of the ELRs plays
only a minor role in defining the growth tendency. When taken together,
these results point to the most favorable conditions for constructing
nanostructured films from natural and distinct recombinant polypeptides
that can be tuned to exhibit specialized biofunctionality for tissue-engineering,
drug-delivery, and biotechnological applications