Publications by authors named "Siddhartha Sankar Jana"

An amphiphilic segmented polyurethane (F-PU-S), with pendant sulfate groups and a flexible hydrocarbon backbone, exhibits intrachain H-bonding-reinforced folding and hierarchical assembly, producing an anionic polymersome with efficient display of sulfate groups at the surface. It shows an excellent antiviral activity against Sendai virus (SV) by inhibiting its entry to the cells. Mechanistic investigation suggests fusion of the SV and the polymersome to produce larger particles in which neither the folded structure of the polymer nor the fusogenic property of the SV exists anymore.

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Cellular uptake is an important event in drug delivery and other biomedical applications. Amphiphilic polymers produce aggregates of different size and shape depending on the intrinsic structural differences and the packing parameter. Although they have been explored for various biomedical applications with immense interest, the relationship between the shape of the aggregate and cellular uptake has been studied only in limited examples.

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Polychlorinated biphenyls (PCBs) are one of the original twelve classes of toxic chemicals covered by the Stockholm Convention on Persistent Organic Pollutants (POP), an international environmental treaty signed in 2001. PCBs are present in the environment as mixtures of multiple isomers at different degree of chlorination. These compounds are manmade and possess useful industrial properties including extreme longevity under harsh conditions, heat absorbance, and the ability to form an oily liquid at room temperature that is useful for electrical utilities and in other industrial applications.

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The genetic diversity of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV2) in several countries sums up to worldwide genetic diversity. In this present study, variations in terms of missense mutations among the SARS-CoV2 genomes from 128 Indian patients, as of May 2020, are accounted and thereby some key findings with some hypotheses were made. These mutations across various genes of these genomes show wide genetic variations in sequence and rapid evolution of SARS-CoV2 virus.

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Two zinc(ii)-NSAID complexes [(phendione)ZnII(NPR)2(H2O)2] (1) and [(phendione)ZnII(MFN)2] (2) (HNPR = naproxen and HMFN = mefenamic acid) of 1,10-phenanthroline-5,6-dione (phendione) were isolated and characterized to evaluate their potential as anti-cancer agents. Each of the complexes contains two equivalents of NSAID per zinc(ii)-phendione unit. The complexes are stable in solution under cell culture conditions.

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A global emergency due to the COVID-19 pandemic demands various studies related to genes and genomes of the SARS-CoV2. Among other important proteins, the role of accessory proteins are of immense importance in replication, regulation of infections of the coronavirus in the hosts. The largest accessory protein in the SARS-CoV2 genome is ORF3a which modulates the host response to the virus infection and consequently it plays an important role in pathogenesis.

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Comparison of amino acid sequence similarity is the fundamental concept behind the protein phylogenetic tree formation. By virtue of this method, we can explain the evolutionary relationships, but further explanations are not possible unless sequences are studied through the chemical nature of individual amino acids. Here we develop a new methodology to characterize the protein sequences on the basis of the chemical nature of the amino acids.

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The synthesis, micellar aggregation, and pH-triggered intracellular drug delivery ability of an amphiphilic statistical copolymer (P2) are studied. Two methacrylate derivatives, one containing a hydrophilic pendant and the other containing a hydrophobic pendant chain, are copolymerized to produce P2. The hydrophobic pendant chain is linked to the polymer backbone by a β-thiopropionate linkage, known to undergo slow hydrolysis at mild acidic pH.

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A conventional drug delivery system requires a delivery vehicle which often faces various problems such as inefficient drug loading into the delivery vehicle and its release, cytotoxicity and biodegradability of the delivery vehicle, etc., whereas a supramolecular gel based self-delivery system delivers a gelator drug at the target site without using any vehicle thereby getting rid of such problems. Here, a simple salt formation strategy has been employed to convert a well known anti-allergic drug (cetirizine) to a supramolecular gelator for the purpose of making a topical gel for in vivo self-delivery applications.

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A simple strategy for designing salt-based supramolecular gelators comprised of various nonsteroidal anti-inflammatory drugs (NSAIDs) and amantadine (AMN) (an antiviral drug) has been demonstrated using a supramolecular synthon approach. Single-crystal and powder X-ray diffraction established the existence of the well-studied gel-forming 1D supramolecular synthon, namely, primary ammonium monocarboxylate (PAM) synthon in all the salts. Remarkably five out of six salts were found to be capable of gelling methyl salicylate (MS)-an important ingredient in commercially available topical gels; one such selected biocompatible salt displayed an anti-inflammatory response in prostaglandin E2 (PGE2 ) assay, thereby indicating their plausible biomedical applications.

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Indomethacin (IND), which is a well-known nonsteroidal anti-inflammatory drug (NSAID), was conjugated with various naturally occurring amino acids. Most of these bioconjugates were capable of gelling pure water, a solution of NaCl (0.9 wt%), and phosphate-buffered saline (pH 7.

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Background: Increasingly, the role of chronic inflammation and its mediators in tumor generation and progression is gaining importance in the field of cancer research. In this context, candidature of non steroidal anti-inflammatory drugs (NSAIDs) as potential anti-tumor therapeutic agent is being evaluated globally. In the present study we have evaluated the anti-cancer effect of a series of newly synthesized naproxen derivatives on human breast cancer cell lines.

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Article Synopsis
  • The study investigates structural oscillations and solvation dynamics in mitochondria of live human breast cells (MCF-7 cancer cells vs. MCF-10A normal cells) using a covalent fluorescence probe called CPM.
  • In normal cells (MCF-10A), CPM binds to discrete mitochondria, while in cancer cells (MCF-7), it labels clustered mitochondria near the nucleus, indicating differences in mitochondrial organization.
  • Results show that the red-ox cycle in MCF-10A leads to greater fluctuations in fluorescence intensity compared to the less efficient red-ox cycle in MCF-7, with solvation times of 850 ps and 1400 ps respectively, suggesting altered mitochondrial dynamics in cancer cells.
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Binding of a specific siRNA to the target mRNA in a live cell (human breast cancer cell, MCF-7) is studied by confocal microscopy. The specific siRNA (labeled with a fluorophore, alexa 488) exhibits much higher intensity of fluorescence in the bound state than in the free (unbound) state. It is observed that repeated unbinding and rebinding of siRNA (to target mRNA) occur before gene silencing.

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The supramolecular synthon approach has been exploited to design simple salt-based supramolecular gelators derived from a non-steroidal anti-inflammatory drug (NSAID) - naproxen; one such biocompatible anti-inflammatory gelator salt was converted into a topical gel that showed excellent in vivo self-delivery application in treating imiquimod (IMQ)-induced skin inflammation in mice.

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A well-known nonsteroidal anti-inflammatory drug (NSAID), namely, naproxen (Np), was conjugated with β-alanine and various combinations of amino alcohols and l-alanine. Quite a few bioconjugates, thus synthesized, were capable of gelling pure water, NaCl solution (0.9 wt %), and phosphate-buffered saline (PBS) (pH 7.

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