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71.
Patnaik S Sharma AK Garg BS Gandhi RP Gupta KC 《International journal of pharmaceutics》2007,342(1-2):184-193
A simple photoresponsive azo-dextran polymer has been investigated for its ability to act as a nanogel drug carrier. Self aggregation of the azo-dextran polymer leads to the formation of nanogels, AD (5 and 10) in aqueous media, which were characterized by TEM and DLS. When examined under UV light (365 nm), the unloaded nanogels, which were observed to be in the range of 120-290 nm, show dependence on the degree of crosslinking, pH and ionic concentration of the dispersed media. Nanogels, AD (5 and 10), have been loaded with a model fluorophore, rhodamine B and a drug, aspirin, by freeze drying an aqueous dispersion of the nanogels in the presence of the substrate dissolved in water or PBS buffer. The release pattern of the encapsulated bio-active molecules from these nanogels was regulated by (trans-cis) photoisomerization of the azobenzene moiety present in the crosslinker. A comparison of the release behavior of the loaded (rhodamine, aspirin) AD (5 and 10) nanogels reveal that the rate of release of the encapsulated active molecules from the nanogels was slower when the azo moiety was in E-configuration as compared to that the azo in the Z-configuration. The in vitro release behavior of drug from these polymeric micellar systems is revelative of the potential of the nanogels for targeted drug delivery in nanomedicine. 相似文献
72.
Pathak A Aggarwal A Kurupati RK Patnaik S Swami A Singh Y Kumar P Vyas SP Gupta KC 《Pharmaceutical research》2007,24(8):1427-1440
Purpose Cationic polymers (i.e. polyallylamine, poly-L-lysine) having primary amino groups are poor transfection agents and possess
high cytotoxicity index when used without any chemical modification and usually entail specific receptor mediated endocytosis
or lysosomotropic agents to execute efficient gene delivery. In this report, primary amino groups of polyallylamine (PAA,
17 kDa) were substituted with imidazolyl functions, which are presumed to enhance endosomal release, and thus enhance its
gene delivery efficiency and eliminate the requirement of external lysosomotropic agents. Further, systems were cross-linked
with polyethylene glycol (PEG) to prepare PAA-IAA-PEG (PIP) nanoparticles and evaluated them in various model cell lines.
Materials and Methods The efficacy of PIP nanoparticles in delivering a plasmid encoding enhanced green fluorescent protein (EGFP) gene was assessed
in COS-1, N2a and HEK293 cell lines, while their cytotoxicity was investigated in COS-1 and HEK293 cell lines. The PAA was
chemically modified using imidazolyl moieties and ionically cross-linked with PEG to engineer nanoparticles. The extent of
substitution was determined by ninhydrin method. The PIP nanoparticles were further characterized by measuring the particle
size (dynamic light scattering and transmission electron microscopy), surface charge (zeta potential), DNA accessibility and
buffering capacity. The cytotoxicity was examined using the MTT method.
Results
In vitro transfection efficiency of synthesized nanoparticles is increased up to several folds compared to native polymer even in
the presence of serum, while maintaining the cell viability over 100% in COS-1 cells. Nanoparticles possess positive zeta
potential between 5.6–13 mV and size range of 185–230 nm in water. The accessibility experiment demonstrated that nanoparticles
with higher degree of imidazolyl substitution formed relatively loose complexes with DNA. An acid-base titration showed enhanced
buffering capacity of modified PAA.
Conclusions The PIP nanoparticles reveal tremendous potential as novel delivery system for achieving improved transfection efficiency,
while keeping the cells at ease. 相似文献
73.
Eosinophilia: secondary, clonal and idiopathic 总被引:5,自引:0,他引:5
Blood eosinophilia signifies either a cytokine-mediated reactive phenomenon (secondary) or an integral phenotype of an underlying haematological neoplasm (primary). Secondary eosinophilia is usually associated with parasitosis in Third World countries and allergic conditions in the West. Primary eosinophilia is operationally classified as being clonal or idiopathic, depending on the respective presence or absence of a molecular, cytogenetic or histological evidence for a myeloid malignancy. The current communication features a comprehensive clinical summary of both secondary and primary eosinophilic disorders with emphasis on recent developments in molecular pathogenesis and treatment. 相似文献
74.
75.
Mohanty I Mohanty P Patnaik S Panda P 《Indian journal of sexually transmitted diseases》2010,31(2):116-117
Amoebic ulcer of the penis is a very rare clinical entity. We report a case of amoebic ulcer of the glans penis in a 47-year-old male homosexual, symptomatic with severe pain and foul-smelling hemopurulent discharge of acute onset. He had received systemic antibiotics like ciprofloxacin and azithromycin prior to presentation with no improvement. Diagnosis was confirmed by wet mount microscopic examination of the discharge. The patient responded well to a course of metronidazole. 相似文献
76.
Kumar HK Modi KD Patnaik SK 《The New England journal of medicine》2008,358(14):1521; author reply 1522
77.
Insulin resistance is a hallmark of type 2 diabetes (T2D). The mechanisms underpinning β-cell mass expansion and their functionality in insulin-resistant states still remain elusive. It has recently been shown that insulin resistance in skeletal muscles leads to production of myokines that impact negatively on β-cell function. We hypothesize that multiple intramuscular injections (IM) of mesenchymal stromal cells (MSCs) at different sites would aid in countering the insulin resistance in T2D. These IM injections are expected to have dual effects in overcoming muscle insulin resistance. It is likely to modulate the micro environmental niche of insulin-insensitive myocytes under the influence of paracrine secretions from MSCs, in turn changing the myokine secretion pattern to positively regulate β-cell function. Further, it may stimulate the satellite cell population to generate new myocytes, which would be insulin-sensitive. If our hypothesis proves to be right, it might offer a user-friendly approach to control T2D. 相似文献
78.
79.