28 research outputs found
DataSheet_1_TLR4 activation by lysozyme induces pain without inflammation.pdf
Mostly, pain has been studied in association with inflammation, until recent studies which indicate that during bacterial infections, pain mechanisms could be independent of the inflammation. Chronic pain can sustain long after the healing from the injury, even in the absence of any visible inflammation. However, the mechanism behind this is not known. We tested inflammation in lysozyme-injected mice foot paw. Interestingly, we observed no inflammation in mice foot paw. Yet, lysozyme injections induced pain in these mice. Lysozyme induces pain in a TLR4-dependent manner and TLR4 activation by its ligands such as LPS leads to inflammatory response. We compared the intracellular signaling of MyD88 and TRIF pathways upon TLR4 activation by lysozyme and LPS to understand the underlying mechanism behind the absence of an inflammatory response upon lysozyme treatment. We observed a TLR4 induced selective TRIF and not MyD88 pathway activation upon lysozyme treatment. This is unlike any other previously known endogenous TLR4 activators. A selective activation of TRIF pathway by lysozyme induces weak inflammatory cytokine response devoid of inflammation. However, lysozyme activates glutamate oxaloacetate transaminase-2 (GOT2) in neurons in a TRIF-dependent manner, resulting in enhanced glutamate response. We propose that this enhanced glutaminergic response could lead to neuronal activation resulting in pain sensation upon lysozyme injections. Collectively we identify that TLR4 activation by lysozyme can induce pain in absence of a significant inflammation. Also, unlike other known TLR4 endogenous activators, lysozyme does not activate MyD88 signaling. These findings uncover a mechanism of selective activation of TRIF pathway by TLR4. This selective TRIF activation induces pain with negligible inflammation, constituting a chronic pain homeostatic mechanism.</p
Effect of Position of Donor Units and Alkyl Groups on Dye-Sensitized Solar Cell Device Performance: Indoline–Aniline Donor-Based Visible Light Active Unsymmetrical Squaraine Dyes
Indoline (In) and aniline (An) donor-based visible light
active
unsymmetrical squaraine (SQ) dyes were synthesized for dye-sensitized
solar cells (DSSCs), where the position of An and In units was changed
with respect to the anchoring group (carboxylic acid) to have In-SQ-An-CO2H and An-SQ-In-CO2H sensitizers, AS1–AS5. Linear or branched alkyl groups were functionalized with the N
atom of either In or An units to control the aggregation of the dyes
on TiO2. AS1–AS5 exhibit an isomeric
Ï€-framework where the squaric acid unit is placed in the middle,
where AS2 and AS5 dyes possess the anchoring
group connected with the An donor, and AS1, AS3, and AS4 dyes having the anchoring group connected
with the In donor. Hence, the conjugation between the middle squaric
acid acceptor unit and the anchoring −CO2H group
is short for AS2, AS5, and AK2 and longer for AS1, AS3, and AS4 dyes. AS dyes showed absorption between 501 and 535
nm with extinction coefficients of 1.46–1.61 × 105 M–1 cm–1. Further, the
isomeric π-framework of An-SQ-In-CO2H and In-SQ-An-CO2H exhibited by means of changing the position of In and An
units a bathochromic shift in the absorption properties of AS2 and AS5 compared to the AS1, AS3, and AS4 dyes. The DSSC device fabricated with the
dyes contains short acceptor-anchoring group distance (AS2 and AS5) showed high photovoltaic performances compared
to the dyes having longer distance (AS1, AS3, and AS4) with the iodolyte (I–/I3–) electrolyte. DSSC device efficiencies
of 5.49, 6.34, 6.16, and 5.57% have been achieved for AS1, AS2, AS3, and AS4 dyes,
respectively; without chenodeoxycholic acid (CDCA), small changes
have been observed in the device performance of the AS dyes with CDCA. Significant changes have been noted in the DSSC
parameters (open-circuit voltage VOC,
short-circuit current JSC, fill factor
ff, and efficiency η) for the AS5 dye while sensitized
with CDCA and showed highest DSSC efficiency of 8.01% in the AS dye series. This study revealed the potential of shorter
SQ acceptor-anchoring group distance over the longer one and the importance
of alkyl groups on the overall DSSC device performance for the unsymmetrical
squaraine dyes
Visible, Far-Red, and Near-Infrared Active Unsymmetrical Squaraine Dyes Based on Extended Conjugation within the Polymethine Framework for Dye-Sensitized Solar Cells
Alkyl group wrapped visible, far-red, and NIR active
unsymmetrical
squaraine dyes with π-extension in the polymethine framework-based AM4-AM7 have been designed, synthesized, and utilized as sensitizers
for dye-sensitized solar cells. To extend the π-conjugation
within the polymethine framework, thiophene moieties have been incorporated
between the donor and acceptor moieties. Absorption spectroscopic
studies revealed that π-extension with each −CC–
unit resulted ∼100 nm of redshift in the charge transfer transition
with the λmaximum of 541, 643, 747, and 833 nm for AM4, AM5, AM6, and AM7 dyes, respectively, with the molar extinction coefficient of >105 M–1cm–1. The π-extended
conjugation-based AM6 and AM7 dyes showed
improved light-harvesting efficiency (LHE), where the AM7 dye showed an LHE of 386 nm at 60%. Electrochemical studies of AM dyes revealed that the HOMO energy level of the sensitizers
has been modulated systematically. Further, π-extension within
the polymethine framework showed a dramatic effect on VOC, JSC, and device efficiency
when move from visible active AM4 to far-red active to
NIR active AM7 dyes. The DSSC efficiencies of 7.35, 5.18,
0.08, and 0.053% have been achieved with the I–/I3– electrolyte (Z-50) for the AM4, AM5, AM6, and AM7 dyes,
respectively. Further, AM4 dye has been cosensitized
with AM5, AM6, and AM7 dyes,
where AM4:AM5 (1:1) composition achieved the maximum
efficiency of 8.12% with I–/I3– electrolyte (Z-50) compared to the other cosensitization compositions
Systematic Evaluation of Biophysical and Functional Characteristics of Selenomethylene-Locked Nucleic Acid-Mediated Inhibition of miR-21
miRNAs constitute
an important layer of gene regulation mediated
by sequence-specific targeting of mRNAs. Aberrant expression of miRNAs
contributes to a host of pathological states. Promoting cancer, miR-21
is upregulated in variety of cancers and promotes tumor progresion
by suppressing a network of tumor suppressor genes. Here we describe
a novel class of bicyclic RNA analogues, selenomethylene-locked nucleic
acid (SeLNA), that display high affinity, improved metabolic stability,
and increased potency for miR-21 inhibition. The thermal stability
(<i>T</i><sub>m</sub>) for duplexes was increased significantly
with incorporation of SeLNA monomers as compared to that of the unmodified
DNA–RNA hybrid. A comprehensive thermodynamic profile obtained
by isothermal titration calorimetry revealed a favorable increase
in the enthalpy of hybridization for SeLNA containing DNA and target
RNA heteroduplexes. SeLNA modifications displayed remarkable binding
affinity for miR-21 target RNA with a <i>K</i><sub>a</sub> of ≤1.05 × 10<sup>8</sup> M<sup>–1</sup>. We
also observed enhanced serum stability for SeLNA–RNA duplexes
with a half-life of ≤36 h. These <i>in vitro</i> results
were well correlated with the antisense activity in cancer cells imparting
up to ∼91% inhibition of miR-21. The functional impact of SeLNA
modifications on miR-21 inhibition was further gauged by investigating
the migration and invasion characterisitics of cancer cells, which
were drastically reduced to ∼49 and ∼55%, respectively,
with SeLNA having four such modifications. Our findings demonstrate
SeLNA as a promising candidate for therapeutics for disease-associated
miRNAs
Targeted Smart pH and Thermoresponsive <i>N,O</i>-Carboxymethyl Chitosan Conjugated Nanogels for Enhanced Therapeutic Efficacy of Doxorubicin in MCF‑7 Breast Cancer Cells
In cancer treatment, developing ideal
anticancer drug delivery
systems to target tumor microenvironment by circumventing various
physiological barriers still remains a daunting challenge. Here, in
our work, a series of pH- and temperature-responsive nanogels based
on polyÂ(N-isopropylacrylamide-co-1-propene-2-3-dicarboxylate-co-2-acrylamido-2-methyl-1-propanesulfonate
[polyÂ(NIPAAm-IA-AMPS)] cross-linked by ethylene glycol dimethacrylate
(EGDMA) were synthesized by random copolymerization. The molar ratio
between monomer–comonomers–cross-linker was varied to
fine-tune the optimum responsiveness of the nanogels. These optimized
nanogels were further coupled to N,O-carboxymethyl chitosan (NOCC) stoichiometrically using EDC–NHS
coupling chemistry to enhance the swelling behavior at lower pH. Interestingly,
these NOCC-g-nanogels, when dispersed in aqueous
media under sonication, attain nanosize and retain their high water-retention
capacity with conspicuous pH and temperature responsiveness (viz.
nanogel shrinkage in size beyond 35 °C and swelled at acidic
pH) in vitro, as reflected by dynamic light scattering data. Doxorubicin
(DOX), a potent anticancer drug, was loaded into these nanogels using
the physical entrapment method. These drug-loaded nanogels exhibited
a slow and sustained DOX release profile at physiological temperature
and cytosolic pH. Furthermore, confocal and TEM results demonstrate
that these nanogels were swiftly internalized by MCF-7 cells, and
cell viability data showed preferential heightened cytotoxicity toward
cancer cells (MCF-7 and MDA-MB231) compared to the MCF10A cells (human
breast epithelial cell). Furthermore, intracellular DNA damage and
cell cycle arrest assays suggest a mitochondrial mediated apoptosis
in MCF-7 cells. This study substantiates our NOCC-g-nanogel platform as an excellent modality for passive diffusive
loading and targeted release of entrapped drug(s) at physiological
conditions in a controlled way for the improved therapeutic efficacy
of the drug in anticancer treatment
The geometry used for simulations of electric field distribution of the three experimental conditions: Center, margin, and healthy brain.
a. e-biopsy sampling electrode is in the middle of the visible tumor (Center). b. e-biopsy sampling electrode is near the visible tumor margin (Margin). c. e-biopsy sampling electrode is far away from the tumor (Healthy brain).</p
Analyzed patterns for protein detection in binary form.
Analyzed patterns for protein detection in binary form.</p
Joule heating of the brain tissue during the application of pulsed electric fields for e-biopsy.
Simulations results for the three scenarios are shown: e-biopsy needle in the center of the tumor (Center, Model A), e-biopsy needle at the distance of 0.5mm from the visible tumor margin (Margin, Model B), and e-biopsy needle at the distance of 10mm (Healthy brain, Model C). Panels a-c show the simulation for high voltage, short-duration protocol: 40 pulses 1000 V, 40 μs, 4 Hz, coupled with the simulation for low voltage, long-duration protocol: 40 pulses 50 V, 15 ms, delivered at 4 Hz. The simulations assume electric tissue conductivities of fully electroporated tissues: brain conductivity 0.882 S m-1, melanoma conductivity 1.47 S m-1 [53]. Arrows show the contour temperature, numbers show the location of the point beneath the electrode, temperature changes in time. Panels d-f show temperature change as a function of distance from e-biopsy harvesting electrode over contours in panels a-c. Panels g-i show temperature change as a function of time at a point located at 0.158mm distance from the e-biopsy harvesting electrode in Model A, 0.144mm in Model B, and 0.123mm in Model C. Simulations results as presented in panels d-f give rise to the high temperatures at points that are relatively very close to the electrode, as the distance from the electrode increase the temperature decrease.</p
Electric field distribution in the brain with melanoma metastasis during e-biopsy.
Simulations results for the three scenarios are shown: e-biopsy needle in the center of the tumor (Center, Model A), e-biopsy needle at the distance of 0.5mm from the visible tumor margin (Margin, Model B), and e-biopsy needle at the distance of 10mm (Healthy brain, Model C). The left set of models shows the electric field distribution at the early stages of electroporation: healthy brain conductivity 0.258 S m-1, melanoma conductivity 0.43 S m-1 [52]. Right panel shows the electric field distribution at the late stages of electroporation when the tissue conductivity increases [53]: brain conductivity 0.882 S m-1, melanoma conductivity 1.47 S m-1.</p
Fig 1 -
a.In vivo bioluminescent imaging of mice 14-days following RET-mCherry-Luc2 cells implantation. b. Excised mice brain with melanoma metastasis with labeled positions for e-biopsy c. hematoxylin and eosin (H&E) stain of the brain with melanoma metastasis. d. Schematic depiction of molecular harvesting with e-biopsy ex vivo.</p