2 research outputs found
New Surface-Enhanced Raman Scattering Platforms: Composite Calcium Carbonate Microspheres Coated with Astralen and Silver Nanoparticles
Surface-enhanced
Raman scattering (SERS) microspectroscopy is a
very promising label-free, noncontact, and nondestructive method for
real-time monitoring of extracellular matrix (ECM) development and
cell integration in scaffolds for tissue engineering. Here, we prepare
a new type of micrometer-sized SERS substrate, core–shell microparticles
composed of solid carbonate core coated with silver nanoparticles
and polyhedral multishell fullerene-like structure, astralen. Astralen
has been assembled with polyallylamine hydrochloride (PAH) by the
layer-by-layer manner followed by Ag nanoparticle formation by means
of a silver mirror reaction, giving the final structure of composite
particles CaCO<sub>3</sub>(PAH/astralen)<sub><i>x</i></sub>/Ag, where <i>x</i> = 1–3. The components of the
microparticle carry multiple functionalities: (i) an easy identification
by Raman imaging (photostable astralen) and (ii) SERS due to a rough
surface of Ag nanoparticles. A combination of Ag and astralen nanoparticles
provides an enhancement of astralen Raman signal by more than 1 order
of magnitude. Raman signals of commonly used scaffold components such
as polylactide and polyvinyl alcohol as well as ECM component (hyaluronic
acid) are significantly enhanced. Thus, we demonstrate that new mechanically
robust and easily detectable (by astralen signal or optically) core–shell
microspheres based on biocompatible CaCO<sub>3</sub> can be used as
SERS platform. Particle design opens many future perspectives for
fabrication of SERS platforms with multiple functions for biomedical
applications, for example, for theranostic
Fibroblasts and polymer composition are essential for bioengineering of airway epithelium on nonwoven scaffolds
To make tissue engineering a truly effective tool, it is necessary to understand how the patterns of specific tissue development are modulated by and depend on the artificial environment. Even the most advanced approaches still do not fully meet the requirements of practical engineering of tracheobronchial epithelium. This study aimed to test the ability of the synthetic and natural nonwoven scaffolds to support the formation of morphological sound airway epithelium including the basement membrane (BM). We also sought to identify the potential role of fibroblasts in this process. Our results showed that nonwoven scaffolds are generally suitable for producing well-differentiated tracheobronchial epithelium (with cilia and goblet cells), while the structure and functionality of the equivalents appeared to be highly dependent on the composition of the scaffolds. Unlike natural scaffolds, synthetic ones supported the formation of the epithelium only when epithelial cells were cocultured with fibroblasts. Fibroblasts also appeared to be obligatory for basal lamina formation, regardless of the type of the nonwoven material used. However, even in the presence of fibroblasts, the synthetic scaffolds were unable to support the formation of the epithelium and of the BM (in particular, basal lamina) as effectively as the natural scaffolds did.</p