16 research outputs found
Enhanced Stability of Polymeric Micelles Based on Postfunctionalized Poly(ethylene glycol)-<i>b</i>-poly(Îł-propargyl l-glutamate): The Substituent Effect
One of the major obstacles that delay the clinical translation
of polymeric micelle drug delivery systems is whether these self-assembled
micelles can retain their integrity in blood following intravenous
(IV) injection. The objective of this study was to evaluate the impact
of core functionalization on the thermodynamic and kinetic stability
of polymeric micelles. The combination of ring-opening polymerization
of <i>N</i>-carboxyanhydride (NCA) with highly efficient
âclickâ coupling has enabled easy and quick access to
a family of polyÂ(ethylene glycol)-block-polyÂ(Îł-R-glutamate)Âs
with exactly the same block lengths, for which the substituent âRâ
is tuned. The structures of these copolymers were carefully characterized
by <sup>1</sup>H NMR, FT-IR, and GPC. When pyrene is used as the fluorescence
probe, the critical micelle concentrations (CMCs) of these polymers
were found to be in the range of 10<sup>â7</sup>â10<sup>â6</sup> M, which indicates good thermodynamic stability for
the self-assembled micelles. The incorporation of polar side groups
in the micelle core leads to high CMC values; however, micelles prepared
from these copolymers are kinetically more stable in the presence
of serum and upon SDS disturbance. It was also observed that these
polymers could effectively encapsulate paclitaxel (PTX) as a model
anticancer drug, and the micelles possessing better kinetic stability
showed better suppression of the initial âburstâ release
and exhibited more sustained release of PTX. These PTX-loaded micelles
exerted comparable cytotoxicity against HeLa cells as the clinically
approved Cremophor PTX formulation, while the block copolymers showed
much lower toxicity compared to the cremophorâethanol mixture.
The present work demonstrated that the <b>PEG-<i>b</i>-PPLG</b> can be a uniform block copolymer platform toward development
of polymeric micelle delivery systems for different drugs through
the facile modification of the PPLG block
Interaction of Anionic Phenylene Ethynylene Polymers with Lipids: From Membrane Embedding to Liposome Fusion
Here
we report spectroscopic studies on the interaction of negatively
charged, amphiphilic polyphenylene ethynylene (PPE) polymers with
liposomes prepared either from negative, positive or zwitterionic
lipids. Emission spectra of PPEs of 7 and 49 average repeat units
bearing carboxylate terminated side chains showed that the polymer
embeds within positively charged lipids where it exists as free chains.
No interaction was observed between PPEs and negatively charged lipids.
Here the polymer remained aggregated giving rise to broad emission
spectra characteristic of the aggregate species. In zwitterionic lipids,
we observed that the majority of the polymer remained aggregated yet
a small fraction readily embedded within the membrane. Titration experiments
revealed that saturation of zwitterionic lipids with polymer typically
occurred at a polymer repeat unit to lipid mole ratio close to 0.05.
No further membrane embedding was observed above that point. For liposomes
prepared from positively charged lipids, saturation was observed at
a PPE repeat unit to lipid mole ratio of âŒ0.1 and liposome
precipitation was observed above this point. FRET studies showed that
precipitation was preceded by lipid mixing and liposome fusion induced
by the PPEs. This behavior was prominent for the longer polymer and
negligible for the shorter polymer at a repeat unit to lipid mole
ratio of 0.05. We postulate that fusion is the consequence of membrane
destabilization whereby the longer polymer gives rise to more extensive
membrane deformation than the shorter polymer
Quantitative NâGlycomic and NâGlycoproteomic Profiling of Peach [Prunus persica (L.) Batsch] during Fruit Ripening
Being
part of the human diet, peach is an important fruit
consumed
worldwide. In the present study, a systematic first insight into the
N-glycosylation of peach fruit during ripening was provided. First,
N-glycome by reactive matrix-assisted laser desorption ionization
time-of-flight (MALDI-TOF) mass spectrometry indicated that 6 of 24
N-glycans of peach were differentially expressed. Second, a comparative
N-glycoproteome was characterized via18O-tagged N-glycosylation site labeling followed by nano-liquid chromatography-electrospray
ionization-tandem mass spectrometry (nLC-ESI-MS/MS). Totally 1464
N-glycosites on 881 N-glycoproteins were identified, among which 291
N-glycosites on 237 N-glycoproteins were expressed differentially
with a fold change value of 1.5 or 0.67. The enrichment analysis of
GO and KEGG revealed that four pathways including other glycan degradation,
phenylpropanoid biosynthesis, amino sugar and nucleotide sugar metabolism,
and protein processing in endoplasmic reticulum were mainly enriched,
in which several important N-glycoproteins with dynamic change during
fruit ripening were further screened out. Our findings on a large
scale for N-glycosylation analysis of peach fruit during ripening
may provide new molecular insights for comprehending N-glycoprotein
functions, which should be of great interest to both glycobiologists
and analytical chemists
Quantitative NâGlycomic and NâGlycoproteomic Profiling of Peach [Prunus persica (L.) Batsch] during Fruit Ripening
Being
part of the human diet, peach is an important fruit
consumed
worldwide. In the present study, a systematic first insight into the
N-glycosylation of peach fruit during ripening was provided. First,
N-glycome by reactive matrix-assisted laser desorption ionization
time-of-flight (MALDI-TOF) mass spectrometry indicated that 6 of 24
N-glycans of peach were differentially expressed. Second, a comparative
N-glycoproteome was characterized via18O-tagged N-glycosylation site labeling followed by nano-liquid chromatography-electrospray
ionization-tandem mass spectrometry (nLC-ESI-MS/MS). Totally 1464
N-glycosites on 881 N-glycoproteins were identified, among which 291
N-glycosites on 237 N-glycoproteins were expressed differentially
with a fold change value of 1.5 or 0.67. The enrichment analysis of
GO and KEGG revealed that four pathways including other glycan degradation,
phenylpropanoid biosynthesis, amino sugar and nucleotide sugar metabolism,
and protein processing in endoplasmic reticulum were mainly enriched,
in which several important N-glycoproteins with dynamic change during
fruit ripening were further screened out. Our findings on a large
scale for N-glycosylation analysis of peach fruit during ripening
may provide new molecular insights for comprehending N-glycoprotein
functions, which should be of great interest to both glycobiologists
and analytical chemists
Quantitative NâGlycomic and NâGlycoproteomic Profiling of Peach [Prunus persica (L.) Batsch] during Fruit Ripening
Being
part of the human diet, peach is an important fruit
consumed
worldwide. In the present study, a systematic first insight into the
N-glycosylation of peach fruit during ripening was provided. First,
N-glycome by reactive matrix-assisted laser desorption ionization
time-of-flight (MALDI-TOF) mass spectrometry indicated that 6 of 24
N-glycans of peach were differentially expressed. Second, a comparative
N-glycoproteome was characterized via18O-tagged N-glycosylation site labeling followed by nano-liquid chromatography-electrospray
ionization-tandem mass spectrometry (nLC-ESI-MS/MS). Totally 1464
N-glycosites on 881 N-glycoproteins were identified, among which 291
N-glycosites on 237 N-glycoproteins were expressed differentially
with a fold change value of 1.5 or 0.67. The enrichment analysis of
GO and KEGG revealed that four pathways including other glycan degradation,
phenylpropanoid biosynthesis, amino sugar and nucleotide sugar metabolism,
and protein processing in endoplasmic reticulum were mainly enriched,
in which several important N-glycoproteins with dynamic change during
fruit ripening were further screened out. Our findings on a large
scale for N-glycosylation analysis of peach fruit during ripening
may provide new molecular insights for comprehending N-glycoprotein
functions, which should be of great interest to both glycobiologists
and analytical chemists
Quantitative NâGlycomic and NâGlycoproteomic Profiling of Peach [Prunus persica (L.) Batsch] during Fruit Ripening
Being
part of the human diet, peach is an important fruit
consumed
worldwide. In the present study, a systematic first insight into the
N-glycosylation of peach fruit during ripening was provided. First,
N-glycome by reactive matrix-assisted laser desorption ionization
time-of-flight (MALDI-TOF) mass spectrometry indicated that 6 of 24
N-glycans of peach were differentially expressed. Second, a comparative
N-glycoproteome was characterized via18O-tagged N-glycosylation site labeling followed by nano-liquid chromatography-electrospray
ionization-tandem mass spectrometry (nLC-ESI-MS/MS). Totally 1464
N-glycosites on 881 N-glycoproteins were identified, among which 291
N-glycosites on 237 N-glycoproteins were expressed differentially
with a fold change value of 1.5 or 0.67. The enrichment analysis of
GO and KEGG revealed that four pathways including other glycan degradation,
phenylpropanoid biosynthesis, amino sugar and nucleotide sugar metabolism,
and protein processing in endoplasmic reticulum were mainly enriched,
in which several important N-glycoproteins with dynamic change during
fruit ripening were further screened out. Our findings on a large
scale for N-glycosylation analysis of peach fruit during ripening
may provide new molecular insights for comprehending N-glycoprotein
functions, which should be of great interest to both glycobiologists
and analytical chemists
Quantitative NâGlycomic and NâGlycoproteomic Profiling of Peach [Prunus persica (L.) Batsch] during Fruit Ripening
Being
part of the human diet, peach is an important fruit
consumed
worldwide. In the present study, a systematic first insight into the
N-glycosylation of peach fruit during ripening was provided. First,
N-glycome by reactive matrix-assisted laser desorption ionization
time-of-flight (MALDI-TOF) mass spectrometry indicated that 6 of 24
N-glycans of peach were differentially expressed. Second, a comparative
N-glycoproteome was characterized via18O-tagged N-glycosylation site labeling followed by nano-liquid chromatography-electrospray
ionization-tandem mass spectrometry (nLC-ESI-MS/MS). Totally 1464
N-glycosites on 881 N-glycoproteins were identified, among which 291
N-glycosites on 237 N-glycoproteins were expressed differentially
with a fold change value of 1.5 or 0.67. The enrichment analysis of
GO and KEGG revealed that four pathways including other glycan degradation,
phenylpropanoid biosynthesis, amino sugar and nucleotide sugar metabolism,
and protein processing in endoplasmic reticulum were mainly enriched,
in which several important N-glycoproteins with dynamic change during
fruit ripening were further screened out. Our findings on a large
scale for N-glycosylation analysis of peach fruit during ripening
may provide new molecular insights for comprehending N-glycoprotein
functions, which should be of great interest to both glycobiologists
and analytical chemists
Quantitative NâGlycomic and NâGlycoproteomic Profiling of Peach [Prunus persica (L.) Batsch] during Fruit Ripening
Being
part of the human diet, peach is an important fruit
consumed
worldwide. In the present study, a systematic first insight into the
N-glycosylation of peach fruit during ripening was provided. First,
N-glycome by reactive matrix-assisted laser desorption ionization
time-of-flight (MALDI-TOF) mass spectrometry indicated that 6 of 24
N-glycans of peach were differentially expressed. Second, a comparative
N-glycoproteome was characterized via18O-tagged N-glycosylation site labeling followed by nano-liquid chromatography-electrospray
ionization-tandem mass spectrometry (nLC-ESI-MS/MS). Totally 1464
N-glycosites on 881 N-glycoproteins were identified, among which 291
N-glycosites on 237 N-glycoproteins were expressed differentially
with a fold change value of 1.5 or 0.67. The enrichment analysis of
GO and KEGG revealed that four pathways including other glycan degradation,
phenylpropanoid biosynthesis, amino sugar and nucleotide sugar metabolism,
and protein processing in endoplasmic reticulum were mainly enriched,
in which several important N-glycoproteins with dynamic change during
fruit ripening were further screened out. Our findings on a large
scale for N-glycosylation analysis of peach fruit during ripening
may provide new molecular insights for comprehending N-glycoprotein
functions, which should be of great interest to both glycobiologists
and analytical chemists
Quantitative NâGlycomic and NâGlycoproteomic Profiling of Peach [Prunus persica (L.) Batsch] during Fruit Ripening
Being
part of the human diet, peach is an important fruit
consumed
worldwide. In the present study, a systematic first insight into the
N-glycosylation of peach fruit during ripening was provided. First,
N-glycome by reactive matrix-assisted laser desorption ionization
time-of-flight (MALDI-TOF) mass spectrometry indicated that 6 of 24
N-glycans of peach were differentially expressed. Second, a comparative
N-glycoproteome was characterized via18O-tagged N-glycosylation site labeling followed by nano-liquid chromatography-electrospray
ionization-tandem mass spectrometry (nLC-ESI-MS/MS). Totally 1464
N-glycosites on 881 N-glycoproteins were identified, among which 291
N-glycosites on 237 N-glycoproteins were expressed differentially
with a fold change value of 1.5 or 0.67. The enrichment analysis of
GO and KEGG revealed that four pathways including other glycan degradation,
phenylpropanoid biosynthesis, amino sugar and nucleotide sugar metabolism,
and protein processing in endoplasmic reticulum were mainly enriched,
in which several important N-glycoproteins with dynamic change during
fruit ripening were further screened out. Our findings on a large
scale for N-glycosylation analysis of peach fruit during ripening
may provide new molecular insights for comprehending N-glycoprotein
functions, which should be of great interest to both glycobiologists
and analytical chemists
Direct infusion ESI-MS spectrum of Hemaoli pulp crude extracts (HPCE) in the negative mode.
<p>Direct infusion ESI-MS spectrum of Hemaoli pulp crude extracts (HPCE) in the negative mode.</p