21 research outputs found
Naringin–Chalcone Bioflavonoid-Protected Nanocolloids: Mode of Flavonoid Adsorption, a Determinant for Protein Extraction
pH Responsive Bioactive Lead Sulfide Nanomaterials: Protein Induced Morphology Control, Bioapplicability, and Bioextraction of Nanomaterials
Precise
morphologies of pH responsive bioactive lead sulfide nanoparticles
(PbS NPs) were synthesized by using industrially and environmentally
important proteins like zein and lysozyme (Lys), and a bioactive polymer
diethylaminoethyl dextran chloride (DEAE). Though, proteins are not
known morphology control agents, zein demonstrated a fine crystal
growth control of PbS NPs better than Lys as well as DEAE, and even
better than conventional surfactants known for their shape control
behavior. Proteins and DEAE coated NPs thus obtained were highly pH
responsive in terms of a color change from light gray (at low pH)
to dark brown (at high pH). Bioapplicability of coated NPs was done
by subjecting them to hemolysis. Both Lys and DEAE coated NPs did
not induce any significant hemolysis and demonstrated their good compatibility
and usability in systemic circulation. For their industrial scale
uses, different extraction methods were proposed by using other industrially
important biomolecules and ionic liquids. Alginic acid and xanthan
gum were excellent complexing agents for an instant extraction of
Lys and DEAE coated NPs from aqueous phase. Ionic liquid exhibited
excellent extraction ability in both organic as well as aqueous phases
Ecofriendly Route To Synthesize Nanomaterials for Biomedical Applications: Bioactive Polymers on Shape-Controlled Effects of Nanomaterials under Different Reaction Conditions
Bioactive
diethylaminoethyl dextran chloride (DEAE-D), a versatile
polymer with numerous industrial applications, was used as a shape-directing
agent for the synthesis of gold (Au) nanoparticles (NPs) in a typical
green chemistry synthetic route. Shape-controlled growth was precisely
directed by the quaternary amine functionalities of DEAE-D, while
its polycationic nature provided simultaneous colloidal stabilization.
Mechanistic aspects were drawn from different sets of reactions in
which DEAE-D was directly used as a reducing agent with respect to
reaction time and temperature. All reactions were simultaneously monitored
with UV–visible studies, and NPs were characterized by TEM,
SEM, and AFM analysis. Shape-controlled synthesis produced large extraordinarily
thin microplates that were converted into small spherical NPs simply
by switching the reaction to seed-growth (S-G) mode. DEAE-D-coated
NPs thus produced were subjected to hemolysis for their possible use
as drug release vehicles in systemic circulation so as to explore
their possible biomedical applications
Multifunctional photo-physiochemical properties of tetronic 304 in aqueous phase: Mechanistic aspects of Au(III) reduction into Au(0)
Block Copolymer Micelles as Nanoreactors for Self-Assembled Morphologies of Gold Nanoparticles
Self-assembled
gold (Au) nanoparticles (NPs) were synthesized in
micelle surface cavities of a L121 block polymer in the presence of
zwitterionic (viz. DPS, TPS, and HPS) and sugar surfactants (OG and
DDM) in aqueous phase at 70 °C by using the surface cavities
of L121 as reducing sites for converting AuÂ(III) into Au(0). All reactions
were monitored simultaneously by UV–visible spectroscopy to
determine the growth kinetics in gold nucleating centers on the basis
of surface plasmon resonance that also helped in tracing the structure
micelle transitions over a wide temperature range of 10–70
°C. The surfactant/L121 mole ratio was changed systematically
from 0.5 to 2.5 by keeping L121 and HAuCl<sub>4</sub> concentrations
constant at 10 and 0.25 mM, respectively, to determine the shape and
size of the micelles and their relation to the self-assembled behavior
of Au NPs. TEM studies were used to have a direct insight into the
morphology of micelle templates and their shape and size for self-assembled
NPs. L121 along with DPS (C12 carbon chain) produced well-defined
micelles loaded with tiny NPs of 3–6 nm in the L121-rich region
of the mixture, while large flower-like compound micelles with a clear
core–shell morphology were produced in the DPS-rich region.
TPS and HPS (C14 and C16 hydrocarbon chains, respectively) with stronger
hydrophobicity than DPS also produced almost similar micelles loaded
with tiny NPs in the L121-rich region, but they disappear in the surfactant-rich
region. Replacement of zwitterionic with ionic surfactants did not
yield micelle templates for self-assembled NPs. Results conclude that
well-defined micelles of L121 are the fine templates for self-assembled
NPs that can only be achieved in the presence of a neutral surfactant
with low concentration and low hydrophobicity
Bipyridinium and Imidazolium Ionic Liquids for Nanomaterials Synthesis: pH Effect, Phase Transfer Behavior, and Protein Extraction
We
demonstrate the potential use of 1,1′-<i>bis</i>(2-(cycloÂhexyloxy)-2-oxoethyl)-[4,4′-bipyridin]-1,1′-diium
bromide (BP) and 1-ethyl-3-methylÂimidazolium chloride (EMI)
ionic liquids (ILs) in in situ synthesis of gold nanoparticles (Au
NPs) without using any external reducing or stabilizing agents. Both
ILs produced nearly monodisperse NPs of 4–8 nm which were present
in the form of self-assembled states. BP coated NPs formed self-assembled
sheets and easily transferred to the organic phase by employing the
water insoluble IL as a phase transfer agent. The efficiency of the
phase transfer process was related to the extent of aggregation as
well as functional groups. Both IL coated NPs were further used to
extract the proteins from the complex biological mixtures. EMI coated
NPs extracted proteins of large molar masses whereas BP coated NPs
were good for the extraction of low molecular mass proteins. This
disparity was controlled by the substituted functional groups of ILs.
Bulky cyclohexyloxy functional groups of BP did not allow extraction
of large molar mass proteins. Such a wide applicability of ILs in
nanomaterials synthesis opens several new applications in the field
of nanomedicine and nanobiotechnology where IL coated NPs can be used
for diverse protein complexation
Lymphomatoid granulomatosis in a pediatric patient.
We report the radiology and pathology of a pediatric patient with lymphomatoid granulomatosis (LG) and review the literature, with an emphasis on the radiological findings and on the small subset of pediatric patients with this rare condition
A rare mutation in lamin A gene is associated with dilated cardiomyopathy in Indian patients
Mutations in lamin A gene (LMNA) are associated with a number of genetic diseases that are collectively termed laminopathies. Most LMNA mutations cause muscular dystrophies and cardiomyopathies. The incidence of LMNA mutations in familial dilated cardiomyopathy (DCM) patients is 5-8 % in Caucasian populations. However, there is no large scale study of LMNA mutations in Indian DCM patients. Hence, we have carried out sequence analysis of LMNA in 239 Indian DCM patients. We have identified a rare non-synonymous mutation c.1873A>T in one patient, which predicted a change in the amino acid serine to cysteine at residue 625. In addition we also identified 20 synonymous single nucleotide polymorphisms in 28 patients. The c.1873A>T mutation was absent in 156 healthy and ethnically matched controls. The serine at position 625 has been earlier identified as a mitotic phosphorylation site in lamin A. Expression of mutant lamin S625C in cultured cells led to a decrease in levels of cyclin dependent kinase inhibitor p21, suggesting compromised cell cycle regulation in these cells. Our study provides important information on the extent of variations in LMNA in Indian DCM patients and identifies a rare mutation in LMNA that is likely to cause deleterious effects on cellular functions
Green Chemistry of Zein Protein Toward the Synthesis of Bioconjugated Nanoparticles: Understanding Unfolding, Fusogenic Behavior, and Hemolysis
Green chemistry of industrially important
zein protein was explored
in aqueous phase toward the synthesis of bioconjugated gold (Au) nanoparticles
(NPs), which allowed us to simultaneously understand the unfolding
behavior of zein with respect to temperature and time. Synthesis of
Au NPs was monitored with simultaneous measurements of UV–visible
absorbance due to the surface plasmon resonance (SPR) of Au NPs that
triggered the adsorption of zein on the NP surface and thus resulted
in its unfolding. Surface adsorption of zein further controlled the
crystal growth of Au NPs, which relied on the degree of unfolding
and fusogenic behavior of zein due to its predominant hydrophobic
nature. The latter property induced a marked blue shift in the SPR
rarely observed in the growing NPs during the nucleation process.
A greater unfolding of zein in fact was instrumental in generating
zein-coated faceted NPs that were subjected to their hemolytic response
for their possible use as drug release vehicles. Zein coating significantly
reduced the hemolysis and made bioconjugated Au NPs the best models
for biomedical applications in nanotechnology