XIV
h
International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
254
T2: P–39
Structure and properties of biomimetic ECM like scaffolds
in in vitro condition
Ewa Stodolak-Zych
1
, Maciej Boguń
2
, Zbigniew Darczyński
2
, and Beata Kolesińska
3
1
Department of Biomterials, AGH University of Science and Technology, Kraków, Poland,
e-mail: stodolak@agh.edu.pl
2
Department of Material and Commodity Sciences and Textile Metrology, Technical University of
Lodz, Poland
3
Institute of Organic Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz,
Poland
Biomimetic scaffolds for tissue engineering and regenerative medicine are based on the natural
compounds (protein, polysaccharides, lipids) which found in the living organism. Simple proteins and
polysaccharides build an extracellular matrix (ECM) play role a natural scaffold for the cells and
tissue. In this work, several models of protein-polysaccharides composition were obtained. All
biomaterials were characterized from the point of view of physicochemical properties and their
structure.
As a polysaccharides component were used: chitin, BOC, and blend of chitin/BOC (in ratio
80/20). Chemical structure of polysaccharides polymer chain (which are N-acetylglucosamine) are
rich in an attractive place to attache short peptides. As a peptides some types of amino acids are used
in the study: tryptophan (W), cysteine (C), tyrosine (Y) combined into simple 6-peptide chains (Table
1). The synthesis of the biomaterials was carried out in two stages: dissolving the peptides in the
alcohol mixture and then combining them with the polysaccharides matrix (65°C/24 h). In the result
protein-polysaccharide systems were dried (to 2D form) and/or lyophilized (to 3D form). The
structure of biomimetic composition was characterized by analysing the FTIR spectra obtained by the
ATR technique (ZnSe/Ge crystal, in range 4000–400 cm
–1
, penetration depth 2µm). It was shown that
the best combination is obtainable when BOC and chitin/BOC blend are used as the polysaccharide
matrix for proteins (significant change in carbonyl and carboxyl groups 1730, 1650, 1080 cm
–1
and
amide groups above 3200 cm
–1
). These materials characterised a relative surface hydrophobicity with
significant dispersion component (IFTd) in total surface energy (IFT). Additionally, the surface
morphology depending on the type of protein: the shape and form of aggregates were observed using
optical microscopy and scanning electron microscopy (SEM). The second stage of the experiment
included environmental impact on materials: all types of biomimetic scaffolds were incubated in in
vitro condition in phosphate buffer (37°C/30 days). It were shown that materials independent of form
(2D or 3D) were stable in in vitro condition: the changes in FTIR spectra was observed in the
vibration range of hydroxyl and amide groups (indicate high wettability of polysaccharides matrices).
Changes in morphology of scaffolds have been reported; higher roughness of the surface is result of
initial phase of material degradation.of the investigated systems.
Tabele 1. Composition of biomimetic scaffolds based on BOC, chitin and BOC/chitin blend.
Peptid/polysaccharides
H-WWWWWW-OH
H-WWCWWC-OH
H-YYCYYC-OH
Chitin
+
+
+
BOC
+
+
+
BOC/chitin
+
+
+
Keywords: extracellular matrix; protein; polysaccharides; ECM stability
Acknowledgment
This work has been supported by the National Science Center, Poland, under grant no. UMO-
2015/19/B/ST8/02594
References
[1] C.M. Rubert Pérez, N. Stephanopoulos, S. Sur, S.S. Lee, C. Newcomb, Ann. Biomed. Eng. 43 (2015) 501.
[2] B. Kolesinska, K.K. Rozniakowski, J. Fraczyk, I. Relich, A.M. Papini, Eur. J. Org. Chem. 401-408 (2015)
1254.
XIV
h
International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
255
T3: P–1
Applications of SiO
2
nanospheres covered by silver layer
as highly active SERS substrates
Jan Krajczewski
1
, Karol Kołątaj
1
, and Andrzej Kudelski
1
1
Laboratory of Molecular Interactions, Faculty of Chemistry, University of Warsaw, ul. Pasteura 1,
02-093 Warsaw, Poland, e-mail: jkrajczewski@chem.uw.edu.pl
It is well known that intensity of SERS spectra depends on many various parameters. For
example, silver substrates generate significantly higher local electromagnetic field than the same
substrates made from gold. Also roughness of surfaces significantly influences on value of the
enhancement factor of the electromagnetic fields. Spherical noble metal nanoparticles generally
do not generate high enhancement factors. Larger enhancement could be obtained by application
of anisotropic nanoparticles or rough surfaces. Previous experiments have shown that embed
silver layers on silica nanospheres is very rough, which leads to creation of so-called ,,hot-
spot’’. This leads to high value of the enhancement factor, what allows to reduce the limit of
detection.
In this work we present easy and repeatable method of synthesis of silica nanospheres.
Presented method is based on polymerization of the SiO
2
precursors like TEOS (tetraethyl
orthosilicate) or APTMS ((3-aminopropyl)-trimethoxysilane) in alcohol solutions in the
presence of ammonium as catalyst [1]. This method allows to control diameter of obtained
nanoparticles by changing amount of some reagents. Morphology of obtained silica nanospheres
were thoroughly investigated on TEM microscope. What is important, reduction of the amount
of TEOS, while maintaining amount of other reagents, does not lead to formation of smaller
nanoparticles. Silica cores were subsequently covered by nanometric layer of silver. Two
different methods of covering was tested: reduction of silver ions in organic solvent by
octylamine [2] and reduction of silver ions in water solution by ascorbic acid. The effect of the
thickness of the silver layer on the optical properties of formed nanostructures was also
investigated. Obtained nanocomposites were tested as optical nanoresonators (as SERS active
substrates). Influence of various factors on SERS activity was tested. Obtained nanocomposite
was used to detect pesticide molecules: thiram and methyl parathion.
Keywords: SERS; SiO
2
nanoparticles; SiO
2
@Ag
References
[1] W. Stöber, A. Fink, J. Colloid Interf. Sci. 26 (1968) 62.
[2] D. Napierska, L. Thomassen, V. Rabolli, D. Lison, L. Gonzalez, M. Kirsch-Volders, J. Martens, P.
Hoet, Small 5 (2099) 846.
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