48 research outputs found
NMR Characterization of PAMAM_G5.NH<sub>2</sub> Entrapped Atomic and Molecular Assemblies
High resolution NMR spectroscopy,
NMR diffusiometry, and NMR cryoporometry
have been used to investigate aqueous solution (D<sub>2</sub>O) of
PAMAM_G5.NH<sub>2</sub>-(Au)<sub>25–100</sub> and PAMAM_G5.NH<sub>2</sub>-(H<sub>2</sub>O)<sub>1000</sub>–(H<sub>2</sub>O)<sub>4000</sub> systems. In the case of dendrimer entrapped gold nanoparticles,
the detailed analysis of high resolution NMR spectra has shown that
no precursor complex formation happens under the circumstances applied
for reduction. Further PGSE results verify that gold nanoparticles
of 1.9–2.6 nm size are entrapped in the outermost part of the
dendrimers and probably more than one dendrimer molecule takes part
in the stabilization process. This system looks like a transition state between dendrimer encapsulated
nanoparticles (DENs) and dendrimer stabilized nanoparticles (DSNs),
and we deal with it in details for what this means. NMR cryoporometry
experiments were performed to detect the encapsulation of water molecules.
The results show that, in the swelling PAMAM_G5.NH<sub>2</sub> dendrimers,
by adding water step by step, there are specific cavities for water
with diameters of 3.6 and 5.2 nm. These cavities have a penetrable
wall for water molecules and probably exist very close to the terminal
groups. The permeability of the cavities is increasing with the increase
of the water content. In dilute solution, the formation of nanoparticles
is determined by the ratio of the rate of nucleation and aggregation
and the latter is affected by the PAMAM_G5.NH<sub>2</sub>
Partitioned Image Data for Machine Learning Analysis of Molecular Biology Figures
<p><strong> Corpus Composition</strong></p>
<p>This data collection provides four types of hand-curated images from open access research articles images. The types are:</p>
<ol>
<li>chart (n=811): data displays such as bar charts, scatterplots, line graphs, etc.</li>
<li>diagram (n=816): any general conceptual diagram</li>
<li>gel (n=811): the output of electrophoresis experiments in Northern, Western, or Southern Blot experiments. </li>
<li>histology (n=816): microscope images of tissue wih histological staining</li>
</ol>
<p>The images are simply organized in subdirectories as individual files. File names are based on PubMed Id and Figure number. </p
Dendrimer-Modified MoS<sub>2</sub> Nanoflakes as a Platform for Combinational Gene Silencing and Photothermal Therapy of Tumors
Exploitation
of novel hybrid nanomaterials for combinational tumor therapy is challenging.
In this work, we synthesized dendrimer-modified MoS<sub>2</sub> nanoflakes
for combinational gene silencing and photothermal therapy (PTT) of
cancer cells. Hydrothermally synthesized MoS<sub>2</sub> nanoflakes
were modified with generation 5 (G5) poly(amidoamine) dendrimers partially
functionalized with lipoic acid via disulfide bond. The formed G5-MoS<sub>2</sub> nanoflakes display good colloidal stability and superior
photothermal conversion efficiency and photothermal stability. With
the dendrimer surface amines on their surface, the G5-MoS<sub>2</sub> nanoflakes are capable of delivering Bcl-2 (B-cell lymphoma-2) siRNA
to cancer cells (4T1 cells, a mouse breast cancer cells) with excellent
transfection efficiency, inducing 47.3% of Bcl-2 protein expression
inhibition. <i>In vitro</i> cell viability assay data show
that cells treated with the G5-MoS<sub>2</sub>/Bcl-2 siRNA polyplexes
under laser irradiation have a viability of 21.0%, which is much lower
than other groups of single mode PTT treatment (45.8%) or single mode
of gene therapy (68.7%). Moreover, the super efficacy of combinational
therapy was further demonstrated by treating a xenografted 4T1 tumor
model <i>in vivo</i>. These results suggest that the synthesized
G5-MoS<sub>2</sub> nanoflakes may be employed as a potential nanoplatform
for combinational gene silencing and PTT of tumors
Partitioned Image Data for Machine Learning Analysis of Molecular Biology Figures
<p><strong> Corpus Composition</strong></p>
<p>This data collection provides four types of hand-curated images from open access research articles images. The types are:</p>
<ol>
<li>chart (n=811): data displays such as bar charts, scatterplots, line graphs, etc.</li>
<li>diagram (n=816): any general conceptual diagram</li>
<li>gel (n=1182): the output of electrophoresis experiments in Northern, Western, or Southern Blot experiments. </li>
<li>histology (n=3458): microscope images of tissue with histological staining</li>
</ol>
<p>The images are simply organized in subdirectories as individual files. File names are based on PubMed Id and Figure number. </p
Multifunctional Lactobionic Acid-Modified Dendrimers for Targeted Drug Delivery to Liver Cancer Cells: Investigating the Role Played by PEG Spacer
We
report the development of a lactobionic acid (LA)-modified multifunctional
dendrimer-based carrier system for targeted therapy of liver cancer
cells overexpressing asialoglycoprotein receptors. In this study,
generation 5 (G5) poly(amidoamine) (PAMAM) dendrimers were sequentially
modified with fluorescein isothiocyanate (FI) and LA (or polyethylene
glycol (PEG)-linked LA, PEG-LA), followed by acetylation of the remaining
dendrimer terminal amines. The synthesized G5.NHAc-FI-LA or G5.NHAc-FI-PEG-LA
conjugates (NHAc denotes acetamide groups) were used to encapsulate
a model anticancer drug doxorubicin (DOX). We show that both conjugates
are able to encapsulate approximately 5.0 DOX molecules within each
dendrimer and the formed dendrimer/DOX complexes are stable under
different pH conditions and different aqueous media. The G5.NHAc-FI-PEG-LA
conjugate appears to have a better cytocompatibility, enables a slightly
faster DOX release rate, and displays better liver cancer cell targeting
ability than the G5.NHAc-FI-LA conjugate without PEG under similar
experimental conditions. Importantly, the developed G5.NHAc-FI-PEG-LA/DOX
complexes are able to specifically inhibit the growth of the target
cells with a better efficiency than the G5.NHAc-FI-LA/DOX complexes
at a relatively high DOX concentration. Our results suggest a key
role played by the PEG spacer that affords the dendrimer platform
with enhanced targeting and therapeutic efficacy of cancer cells.
The developed LA-modified multifunctional dendrimer conjugate with
a PEG spacer may be used as a delivery system for targeted liver cancer
therapy and offers new opportunities in the design of multifunctional
drug carriers for targeted cancer therapy applications
Acetylated Polyethylenimine-Entrapped Gold Nanoparticles Enable Negative Computed Tomography Imaging of Orthotopic Hepatic Carcinoma
Developing
an effective computed tomography (CT) contrast agent
is still a challenging task for precise diagnosis of hepatic carcinoma
(HCC). Here, we present the use of acetylated polyethylenimine (PEI)-entrapped
gold nanoparticles (Ac-PE-AuNPs) without antifouling modification
for negative CT imaging of HCC. PEI was first linked to fluorescein
isothiocyanate (FI) and then utilized as a vehicle for the entrapment
of AuNPs. The particles were then acetylated to reduce its positive
surface potential. The designed Ac-PE-AuNPs were characterized by
various techniques. We find that the Ac-PE-AuNPs with a uniform size
distribution (mean diameter = 2.3 nm) are colloidally stable and possess
low toxicity in the studied range of concentration. Owing to the fact
that the particles without additional antifouling modification were
mainly gathered in liver, the Ac-PE-AuNPs could greatly improve the
CT contrast enhancement of normal liver, whereas poor CT contrast
enhancement appeared in liver necrosis region caused by HCC. As a
result, HCC could be easily and precisely diagnosed. The designed
Ac-PE-AuNPs were demonstrated to have biocompatibility through in
vivo biodistribution and histological studies, hence holding an enormous
potential to be adopted as an effective negative CT contrast agent
for diagnosis of hepatoma carcinoma
A Microfluidic Chip Integrated with Hyaluronic Acid-Functionalized Electrospun Chitosan Nanofibers for Specific Capture and Nondestructive Release of CD44-Overexpressing Circulating Tumor Cells
Detection
of circulating tumor cells (CTCs) in peripheral blood
is of paramount significance for early-stage cancer diagnosis, estimation
of cancer development, and individualized cancer therapy. Herein,
we report the development of hyaluronic acid (HA)-functionalized electrospun
chitosan nanofiber (CNF)-integrated microfludic platform for highly
specific capture and nondestructive release of CTCs. First, electrospun
CNFs were formed and modified with zwitterion of carboxyl betaine
acrylamide (CBAA) via Michael addition reaction and then targeting
ligand HA through a disulfide bond. We show that the formed nanofibers
still maintain the smooth fibrous morphology after sequential surface
modifications, have a good hemocompatibility, and exhibit an excellent
antifouling property due to the CBAA modification. After being embedded
within a microfluidic chip, the fibrous mat can capture cancer cells
(A549, a human lung cancer cell line) with an efficiency of 91% at
a flow rate of 1.0 mL/h. Additionally, intact release of cancer cells
is able to be achieved after treatment with glutathione for 40 min
to have a release efficiency of 90%. Clinical applications show that
9 of 10 nonsmall-cell lung cancer patients and 5 of 5 breast cancer
patients are diagnosed to have CTCs (1 to 18 CTCs per mL of blood).
Our results suggest that the developed microfluidic system integrated
with functionalized CNF mats may be employed for effective CTCs capture
for clinical diagnosis of cancer
Construction of Hybrid Alginate Nanogels Loaded with Manganese Oxide Nanoparticles for Enhanced Tumor Magnetic Resonance Imaging
Development of sensitive
contrast agents for positive magnetic
resonance (MR) imaging of biosystems still remains a great challenge.
Herein, we report a facile process to construct hybrid alginate (AG)
nanogels (NGs) loaded with manganese oxide (Mn<sub>3</sub>O<sub>4</sub>) nanoparticles (NPs) for enhanced tumor MR imaging. The obtained
AG/PEI-Mn<sub>3</sub>O<sub>4</sub> NGs with a mean size of 141.6 nm
display excellent colloidal stability in aqueous solution and good
cytocompatibility in the studied concentration range. Moreover, the
hybrid NGs have a high <i>r</i><sub>1</sub> relaxivity of
26.12 mM<sup>–1</sup> s<sup>–1</sup>, which is about
19.5 times higher than that of PEI-Mn<sub>3</sub>O<sub>4</sub> NPs
with PEI surface amine acetylated (PEI.Ac–Mn<sub>3</sub>O<sub>4</sub> NPs). Furthermore, the AG/PEI-Mn<sub>3</sub>O<sub>4</sub> NGs presented longer blood circulation time and better tumor MR
imaging performances <i>in vivo</i> than PEI.Ac–Mn<sub>3</sub>O<sub>4</sub> NPs. With the good biosafety confirmed by histological
examinations, the developed AG/PEI-Mn<sub>3</sub>O<sub>4</sub> NGs
may be potentially used as an efficient contrast agent for enhanced
MR imaging of different biosystems
T<sub>2</sub> signal intensity value of the wall of ectopic endometriotic lesions at different time points.
<p>T<sub>2</sub> signal intensity value of the wall of ectopic endometriotic lesions at different time points.</p
The surgically induced ectopic endometriotic lesions at four weeks post operation.
<p>The tubal cystic structure with a size of 23.8×4.7×3.9 mm was noticed at the fixed site (long arrow). The ectopic lesions were full of liquids and the small dendritic vessels on the surface of the wall were also clearly observed. Note that a strip of the adhesion tissues (arrowhead) was also observed between the ectopic lesions and abdominal wall.</p