2 research outputs found
Liposomes as Drug Deposits in Multilayered Polymer Films
The ex vivo growth of implantable
hepatic or cardiac tissue remains a challenge and novel approaches
are highly sought after. We report an approach to use liposomes embedded
within multilayered films as drug deposits to deliver active cargo
to adherent cells. We verify and characterize the assembly of poly(l-lysine) (PLL)/alginate, PLL/poly(l-glutamic acid),
PLL/poly(methacrylic acid) (PMA), and PLL/cholesterol-modified PMA
(PMA<sub>c</sub>) films, and assess the myoblast and hepatocyte adhesion
to these coatings using different numbers of polyelectrolyte layers.
The assembly of liposome-containing multilayered coatings is monitored
by QCM-D, and the films are visualized using microscopy. The myoblast
and hepatocyte adhesion to these films using PLL/PMA<sub>c</sub> or
poly(styrenesulfonate) (PSS)/poly(allyl amine hydrochloride) (PAH)
as capping layers is evaluated. Finally, the uptake of fluorescent
lipids from the surface by these cells is demonstrated and compared.
The activity of this liposome-containing coating is confirmed for
both cell lines by trapping the small cytotoxic compound thiocoraline
within the liposomes. It is shown that the biological response depends
on the number of capping layers, and is different for the two cell
lines when the compound is delivered from the surface, while it is
similar when administered from solution. Taken together, we demonstrate
the potential of liposomes as drug deposits in multilayered films
for surface-mediated drug delivery
Assembly of Poly(dopamine)/Poly(<i>N</i>‑isopropylacrylamide) Mixed Films and Their Temperature-Dependent Interaction with Proteins, Liposomes, and Cells
Many biomedical applications benefit
from responsive polymer coatings.
The properties of poly(dopamine) (PDA) films can be affected by codepositing
dopamine (DA) with the temperature-responsive polymer poly(<i>N</i>-isopropylacrylamide) (pNiPAAm). We characterize the film
assembly at 24 and 39 °C using DA and aminated or carboxylated
pNiPAAm by a quartz crystal microbalance with dissipation monitoring
(QCM-D), X-ray photoelectron spectroscopy, UV–vis, ellipsometry,
and atomic force microscopy. It was found that pNiPAAm with both types
of end groups are incorporated into the films. We then identified
a temperature-dependent adsorption behavior of proteins and liposomes
to these PDA and pNiPAAm containing coatings by QCM-D and optical
microscopy. Finally, a difference in myoblast cell response was found
when these cells were allowed to adhere to these coatings. Taken together,
these fundamental findings considerably broaden the potential biomedical
applications of PDA films due to the added temperature responsiveness