3 research outputs found
Polysaccharide-Based PolyanionâPolycationâPolyanion Ternary Systems. A Preliminary Analysis of Interpolyelectrolyte Interactions in Dilute Solutions
The present contribution deals with the preparation and
characterization
of ternary mixtures of polysaccharides with potential applications
in the field of tissue engineering. Two natural polyanions, i.e.,
alginate and hyaluronic acid, and a polycation, a lactose-modified
chitosan (chitlac), were mixed in dilute conditions. The miscibility
between the three components was explored in the presence of different
amounts of supporting simple salt. These analyses allowed to identify
the experimental conditions avoiding polymer phase separation and
leading to either solution of independent polymers or soluble nonstoichiometric
interpolyelectrolyte complexes. The characterization of the interpolyelectrolyte
complexes was tackled by means of viscometry, light scattering, fluorescence
quenching, and energy transfer. The electrostatic interactions taking
place among the different polyelectrolytes led to synergistic effects
on the viscosity of the polymer mixtures which strongly depend on
the ionic strength. It has been found that, starting from binary soluble
complexes of alginate and chitlac, the addition of hyaluronan led
to the dissolution of the complexes. At variance, the addition of
alginate to a phase-separated binary mixture of hyaluronan and chitlac
led to the formation of soluble complexes composed of all three polysaccharides
and, eventually, to their dissolution. In addition, the results showed
that at low ionic strength the overall properties of the ternary mixtures
depend on their order of mixing
Biomimetic Polymers for Cardiac Tissue Engineering
Heart
failure is a morbid disorder characterized by progressive
cardiomyocyte (CM) dysfunction and death. Interest in cell-based therapies
is growing, but sustainability of injected CMs remains a challenge.
To mitigate this, we developed an injectable biomimetic Reverse Thermal
Gel (RTG) specifically engineered to support long-term CM survival.
This RTG biopolymer provided a solution-based delivery vehicle of
CMs, which transitioned to a gel-based matrix shortly after reaching
body temperature. In this study we tested the suitability of this
biopolymer to sustain CM viability. The RTG was biomolecule-functionalized
with poly-l-lysine or laminin. Neonatal rat ventricular myocytes
(NRVM) and adult rat ventricular myocytes (ARVM) were cultured in
plain-RTG and biomolecule-functionalized-RTG both under 3-dimensional
(3D) conditions. Traditional 2D biomolecule-coated dishes were used
as controls. We found that the RTG-lysine stimulated NRVM to spread
and form heart-like functional syncytia. Regarding cell contraction,
in both RTG and RTG-lysine, beating cells were recorded after 21 days.
Additionally, more than 50% (<i>p</i> value < 0.05; <i>n</i> = 5) viable ARVMs, characterized by a well-defined cardiac
phenotype represented by sarcomeric cross-striations, were found in
the RTG-laminin after 8 days. These results exhibit the tremendous
potential of a minimally invasive CM transplantation through our designed
RTG-cell therapy platform
Additional file 1 of EMID2 is a novel biotherapeutic for aggressive cancers identified by in vivo screening
Supplementary Material 1: Table S1. Composition of the pilot AAV9 poo