http://hdl.handle.net/123456789/1727 Sun, 04 Jun 2023 17:37:50 GMT 2023-06-04T17:37:50Z http://hdl.handle.net/123456789/2115 Title: Oligosaccharides production from lignocellulosic biomass through bioprocessing and synthetic biology approach Authors: Purohit, Anjali; Yadav, Sudesh Kumar Sun, 01 Aug 2021 00:00:00 GMT http://hdl.handle.net/123456789/2115 2021-08-01T00:00:00Z http://hdl.handle.net/123456789/2114 Title: Stimuli responsive amino-acid/ peptide/ peptide- metal hybrid nanostructures for site specific anti-canser drug delivery Authors: Chibh, Sonika; Panda, Jiban Jyothi Abstract: Cancer is one of the most serious lethal illnesses in today’s world and a major health concern after cardiac illnesses in developing countries which does not have any frontier. Cancer has a higher probability of being cured if diagnosed at the onset and treated effectively. Present treatment options for cancer therapy include chemotherapy, surgical therapy and radiation therapy, immunotherapy or either the combination of these therapies. While chemotherapy is a conventional and extensively used treatment method for most of the cancer patients, still it suffers from limitations like fast elimination of the drug molecules, low solubility of most of the chemotherapeutics and drug resistance. Henceforth, nowadays research has been purposed a large proportion to develop cancer therapeutics that can accurately target tumor or cancerous cells, without harming healthy cells. Flourishing since years, self-assembly driven nanostructures are rationally designed with great potential as diagnostic or therapeutic delivery vehicles. For this aim, the present thesis is focused on the development of morphologically different nanostructures starting from a single amino acid to dipeptide to tetrapeptide-based nanostructures as stimuli-responsive therapeutic delivery vehicle in anti-cancer therapy. Very initially, we tried to explore the self-assembly of mere a single amino acid, N-(9- Fluorenylmethoxycarbonyl)-S-trityl-L-cysteine (Fmoc-Cys(Trt)-OH) through microfluidics and manual method. Very interestingly, we observed bowl like formation using microfluidic self-assembly method, whereas through manual method spherical structures were observed. These bowls were further infused into a vesicular shell consisting of amino acid N-(tert- Butoxycarbonyl)-S-trityl-L-cysteine, carrying dual acid labile groups, the triphenylmethyl and the tert-butyloxycarbonyl, to make them pH-responsive system. To illustrate the potential use of the NB-shells in the field of anticancer drug delivery, the particles were loaded with doxorubicin (Dox) with an encapsulation efficiency of 42% and Dox loaded NB-shellsexhibited enhanced efficacy in C6 glioma cells and in an animal model of glioblastoma, where the nanoformulations demonstrated significantly higher retardation of tumour volume as compared to free dox. Moving a step further, to develop dual combined chemo-photodynamic- responsive system using bowl shaped structures, doxorubicin-curcumin-amino acid-based composite microbowls (CMBs) were synthesized following miniaturised fluid flow based self- assembly. The CMBs were further exploited as dual chemo-photodynamic therapeutic agents in C6 glioma cells cultured in both 2D monolayer and as 3D spheroids. These CMBs showed synergistic and visible (blue) light sensitive cell-killing effects in both C6 cells and in the 3D spheroids. Further, we tried to develop stimuli- responsive dipeptide (R  F and CF) based self- assembled nanostructures. Firstly, we tried to develop cancer targeted and redox-responsive NPs from disulfide-linked oxidized cysteine-phenylalanine (CF). The NPs were conjugated with folic acid (FA) to specifically target cancer cells and the presence of disulfide bonds would enable the disintegration of the particles in the presence of elevated levels of glutathione (GSH) in cancer cells. We have also demonstrated enhanced uptake of FA derivatized NPs (FA-CFO- NPs) in cancerous cells (C6 glioma and B16F10 melanoma cells) than in normal cells (HEK293T cells), due to the overexpression of FA receptors on the surface of cancer cells. In another dipeptide-based studies, we synthesized NPs from a dipeptide RΔF, containing arginine at the N-terminus and a modified amino acid residue, α, β-dehydrophenylalanine (ΔPhe) at the C-terminus, and determined their responsiveness towards acidic, neutral and alkaline pH (2,7 and 10) conditions. These NPs were loaded with the anticancer drug Dox with a rationale to get a pH-responsive release of Dox specifically into the acidic microenvironment of cancer cells rather than in normal cells to curtail nonspecific toxicity. In-vitro efficacy studies carried-out in various cancer cells revealed that RΔF-Dox-NPs exhibited higher efficacy with 1.65-, 1.95- and 13.34-fold lower IC50 values in comparison to Dox in C6, HCT- 116 and AGS cell lines. Starting from a single amino acid self-assembly to dipeptide, we furthertried to develop tetrapeptide-based self-assembled auto-fluorescent nanosheets as an anti- cancer drug delivery vehicle. Herein, we reported the synthesis and application of MoS 2 exfoliation using peptide-based nanosheets as a multi-modal chemo/siRNA/NIR-responsive drug delivery system in targeting glioma. We developed a hybrid nanosheets as a delivery system acclimatizing Dox and Galectin-1 (gal-1) siRNA to allow NIR-responsive delivery. Various studies have demonstrated that slight change in the morphology, size and surface charge of the nanostructures greatly impact the extent and rate of their cellular internalization efficiency. However, precisely controlling the structural morphology of these nanostructures using different parameters continues to be a key challenge. Moreover, we had also tried to understand the cellular internalization behaviour of morphologically different multi-stimuli- responsive 1D and 2D nanostructures (nanofibers, spherical NPs, nanosheets) originated from a single tetrapeptide molecule. Hence, taking advantage of our morphologically different particles emanating from the same peptide monomer, we ventured on to further explore the intra-cellular fate of our nanostructures. We observed that the nanostructures’ cellular internalization is a complex process that gets influenced by particle morphology and this might further affect their intracellular drug delivery potential. Overall, these studies provide initial cues to prepare environment responsive shape shifting peptide-nano assemblies. These studies also provide unique opportunities for undermining specific design criteria to control cellular fate and internalization efficiency of the nanostructures. Thus, in total the assortment of different morphologically tuned stimuli-responsive nanostructures has been developed in this thesis represents a multifaceted combinatorial platform. Such all-in-one anti-cancer combotherapeutic modalities are interesting and superior to many other reported nanosystems in terms of their biocompatibility and ease of fabrication. Sun, 01 May 2022 00:00:00 GMT http://hdl.handle.net/123456789/2114 2022-05-01T00:00:00Z http://hdl.handle.net/123456789/2113 Title: Self- assembly of Supramolecular nanoconjugates at Liquid-liquid interface Authors: Varshney, Rohit; Patra, Debabrata Abstract: Nanoconjugates stabilized Pickering emulsions have attracted immense interest in past decade and have created opportunity for the development of novel materials with unique physical properties. The physical properties of these emulsions such as permeability, mechanical strength, and biocompatibility can be precisely controlled through the judicious choice of colloids and preparation conditions for their assembly at interface. These nanoconjugates form 2D layer at liquid-liquid interface by cooperative interactions and result in forming defect-free nanostructures. This thesis focuses on designing supramolecular nanoconjugates to stabilize emulsions for application in catalysis, controlled permeability and flow-based detection. In brief, our first approach demonstrated one-step microfluidic fabrication of enzyme immobilized polymeric microcapsules using nanoparticle-enzyme conjugates. These solid core microcapsules provided robustness and prevented enzyme leaching, thus producing a highly reusable scaffold for biocatalysis. Next work demonstrated that these biocatalytic microcapsules can be used as microscale engine to mimic the life-like behavior of microorganism such as fluid actuation and buoyancy driven motion. The system was further developed to provide muti-modal catalysis using mpg-C 3 N 4 - enzyme conjugates. These microcapsules were able to perform biocatalysis as well as photocatalysis simultaneously, thus providing a pathway for environmental remediation for biomedical wastes. In another approach, we developed pillar[5]arene nano- conjugates stabilized emulsions which can be utilized for fluid flow-based lab-on-chip detection of toxins. Finally, we explored jamming of supramolecular constructs at liquid- liquid interface to control the molecular permeability of the 2D films. In brief, we have synthesized Pickering emulsions employing non-covalent self-assembled nanoconjugates which generate supramolecular assemblies and stabilize liquid-liquid interface. These MCs demonstrated their potential applications in catalysis, fluid flow based detection, encapsulation, and controlled release. Mon, 01 Nov 2021 00:00:00 GMT http://hdl.handle.net/123456789/2113 2021-11-01T00:00:00Z http://hdl.handle.net/123456789/2112 Title: Ultrafast plasmon relaxation dynamics in metal(AU) and near infrared active non-stoichiometric ccemiconductor(Cu2-xS/Se) Nanocrystals Authors: Ghorai, Nandan; Ghosh, H. N. Abstract: This thesis highlights the ultrafast plasmon dynamics of metallic (Au) as well as non- stoichiometric semiconductor (Cu 2-x S/Se) nano-materials. Plasmonic nanocrystals (NCs) are versatile class of nano materials which remain in the focus of nanoscience research, due to their enormous interest in fundamental science as well as applications. Intriguingly, plasmonic properties of the NCs can be easily manipulated by changing the size, morphology, carrier concentration and reaction temperature during synthesis. Therefore, fundamental studies especially ultrafast transient absorption (TA) measurements of plasmonic nanomaterials is extremely important to optimize the device efficiency made out of the above materials. This thesis discusses ultrafast plasmon dynamics of Au nanoparticles (NPs) embedded in different glassy dielectric films (SiO 2 and SiO 2 -TiO 2 ) under different pump excitation (400 and 700 nm). Along with, temperature dependent plasmon dynamics has also been investigated and electron-phonon scattering time is estimated, which decreases at cryogenic temperature (5K). Further, near infrared (IR) plasmon dynamics in non-stoichiometric Cu 2-x S/Se NCs were carried out and perceived TA bleach was span over long IR region due to intra-band transition within the valence band of Cu 2- x S/Se NCs. Hole-phonon coupling constant (G) has been estimated for different systems and at different pump excitation. Again hot carrier dynamics of non-stoichiometric Cu 2-x Se NCs has been carried out in presence and absence of methylene blue (MB). TA study shows noticeable ultrafast hot hole delocalization in presence of MB. However, when the NCs caped with short chin surface ligand, we observed more prominent hot hole transfer in Cu 2-x Se NC system. Furthermore, Cu 2-x S NCs were caped with two different surface ligands (oleylamine and oleic acid). Herein, oleic acid has deprotonated functional group and can scavenge hot hole from Cu 2-x S NCs more efficiently. Subsequently, we have represented hot hole delocalization dynamics in p-n hetero-junction (Cu 2- x Se/CdSe). TA spectra and kinetic demonstrate hot hole delocalization/transfer in hetero nanocrystals. Fabricated thin-film plasmonic device exhibits excellent conductivity in accordance with the results of TA measurements. This thesis work will open up a new avenue for harvesting visible to near infrared photon for the development of modern solar cell, photo-detector and fast photo-device application. Wed, 01 Dec 2021 00:00:00 GMT http://hdl.handle.net/123456789/2112 2021-12-01T00:00:00Z