2 research outputs found
Nucleic Acid-Scavenging Electrospun Nanofibrous Meshes for Suppressing Inflammatory Responses
Fragmented nucleic acids are potent stimulators for inflammatory
responses provoking pathological outcomes by activating adaptive immunity.
In this study, highly cationic surfaces were prepared on electrospun
nanofibrous meshes to scavenge nucleic acids to the surfaces. PolyÂ(ε-caprolactone)
[PCL]-polyÂ(ethylenimine) [PEI] block copolymers were synthesized by
coupling the carboxyl-terminated PCL to the primary amines of branched
PEI. Polymeric solutions composed of PCL–PEI and PCL were electrospun
to nanofibrous mats, and the surfaces were further methylated to prepare
highly cationic surfaces on the mats. Raman spectroscopy revealed
that the presence of increased methylated amines on the surfaces of
the mats compared to unmodified mats. The methylated surfaces showed
significant increases of wettability after methylation, suggesting
highly charged surfaces caused by methylation of the primary amines.
When the blend ratio of PCL–PEI was increased, the scavenged
DNA was also increased, and the methylation further strengthened the
scavenging ability of the mats. Fluorescently labeled oligodeoxynucleic
acids were significantly adsorbed on the surface of the mats depending
on the amounts of PCL–PEI and the degree of methylation. In
the presence of the methylated nanofibrous mats, inflammatory responses
induced by CpG oligonucleotides in murine macrophages were significantly
reduced, which was confirmed by measuring inflammatory cytokine levels
including TNF-α and IFN-γ
Electrospun Nanofibrous Sheets for Selective Cell Capturing in Continuous Flow in Microchannels
Electrospun nanofibrous meshes were
surface-modified for selective
capturing of specific cells from a continuous flow in PDMS microchannels.
We electrospun nanofibrous mats composed of polyÂ(ε-carprolactone)
(PCL) and amine-functionalized block copolymers composed of PCL and
polyÂ(ethylenimine) (PEI). A mixture of biotinylated PEG and blunt
PEG was chemically tethered to the nanofibrous mats via the surface-exposed
amines on the mat. The degree of biotinylation was fluorescently and
quantitatively assayed for confirming the surface-biotinylation levels
for avidin-specific binding. The incorporation level of avidin gradually
increased when the blend ratio of biotinylated PEG on the mat increased,
confirming the manipulated surfaces with various degree of biotinylation.
Biotinylated cells were incubated with avidin-coated biotinylated
mats and the specific binding of biotinylated cells was monitored
in a microfluidic channel with a continuous flow of culture medium,
which suggests efficient and selective capturing of the biotinylated
cells on the nanofibrous mat