Venkatesh Chelvam's research while affiliated with Indian Institute of Technology Indore and other places

Publications (38)

Chapter
Nuclear medicine uses radioactive probes, commonly referred to as radiotracers, for the diagnosis and treatment of diseases. As of today, single photon emission computed tomography (SPECT) has revolutionized the field of nuclear imaging and is one of the most important medical imaging methods providing functional information about physiologic and p...
Article
In recent years, 3D culture of tumor spheroids has managed to revolutionize cancer research and drug discovery. 2D monolayer cells grown in cell culture flasks undergo radical changes in cell behavior, structure, and function owing to varying environmental cues and are unable to provide predictive data for preclinical evaluation. 3D tumor spheroids...
Article
Early diagnosis of prostate cancer (PCa) is crucial for staging, treatment and management of patients. Prostate specific membrane antigen (PSMA), highly over-expressed on PCa cells, is an excellent target for selective imaging of PCa. In recent years, various scaffolds have been explored as potential carriers to target diagnostic and therapeutic ag...
Article
Full-text available
1,5 - Disubstituted indole-2-carboxaldehyde derivatives 1a – h and glycine alkyl esters 2a – c are shown to undergo a novel cascade imination-heterocylization in the presence of the organic base DIPEA to provide 1-indolyl-3,5,8-substituted γ-carbolines 3aa – ea in good yields. The γ-carbolines are fluorescent and exhibit anticancer activities again...
Article
Prostate-specific membrane antigen (PSMA) is a viable diagnostic biomarker for the detection and treatment of prostate cancer. Although numerous imaging techniques and fluorescent probes have been developed, targeted imaging and intraoperative surgery continue to remain as a proof-of-concept with a severe lack of tools having high affinity and pene...
Article
The current challenge in fluorescent guided surgery (FGS) for prostate cancer (PCa) is in design of imaging probes with high selectivity, clear visualization of tumour margins, and minimal toxicity. This report aims to design and develop a novel NIR-nanoprobe, and evaluate its potential in penetration of PCa tumour tissues. PSMA receptor-targeted q...
Article
Full-text available
We report herein, Se doped ZnO nanorods, a new heterogeneous base catalyst for transesterification of vegetable oil to fatty methyl esters (FAME) or biodiesel. Surface area defects, mainly oxygen interstitials and oxygen vacancies, in the crystal lattice play essential role in enhancing basic site reactivity. The optimum transesterification reactio...
Article
Tubulysins are natural anticancer molecules that directly bind and inhibit tubulin polymerization in actively dividing cells leading to apoptosis and cell death. Structurally, tubulysins are linear tetrapeptides, constituted by a natural amino acid (Ile) and three non-canonical amino acids (Mep, Tuv, and Tup). Herein, we report a convenient strateg...
Preprint
Full-text available
1,5 - Disubstituted indole-2-carboxaldehyde derivatives ( 1a – h ) and glycine alkyl esters ( 2a – c ) are shown to undergo a novel cascade imination-heterocylisation in the presence of organic base DIPEA to provide 1-indolyl 3,5,8-substituted g-carbolines ( 3aa – ea ) in good yields. The g-carbolines are fluorescent and exhibit anticancer activiti...
Article
Se doped ZnO nanorods prepared by mechanothermal method with generation of multiple zinc (VZn), oxygen (VO) vacancies and oxygen interstitials (Oi) defects induce multicolor emissions by single and two-photon single wavelength excitations. The photoluminescence spectrum under single-photon excitation exhibits a broad multicolor emission peak from 4...
Article
Tubulysin family of natural products is a class of highly cytotoxic tetrapeptides that induce apoptosis by arresting the mitosis of a cell. In this article, we have analysed 49 reported tubulysin derivatives with known IC50 values to develop two and three-dimensional quantitative structure-activity relationships (2D and 3D QSAR) to explore the crit...
Article
A serendipitous discovery of a novel one-pot synthesis of 4,6-disubstituted 5-azaindoles is reported herein. In the presence of Hunig’s base, various N-substituted pyrrole-2-carboxaldehydes have been efficiently transformed into corresponding 4,6-disubstituted...
Article
Full-text available
Background Prostate‐specific membrane antigen (PSMA), overexpressed on prostate cancer (PCa), is a well‐characterized cell surface protein to selectively diagnose PCa. PSMA's unique characteristics and its 1000‐fold higher expression in PCa compared with other tissues renders it as a suitable biomarker for detection of PCa in its early stage. In th...
Article
In this article, we have explored the chemical interactions of tyrosine-based asymmetric urea ligands in the binding pockets of prostate specific membrane antigen (PSMA) through in silico studies. The S1 pocket of the PSMA protein offers better scope for modifications in the urea ligands to improve the binding affinity. Accordingly, tyrosine-based...
Article
In the last two decades, tubulysins have emerged as alternatives to microtubule depolymerizing agents such as colchicine and vinblastine, which are well-established anticancer agents. However, the complex structure of tubulysins has always posed a challenge for synthetic chemists to scale up the production of these compounds. We report a new strate...
Article
Full-text available
In this article, we have successfully designed and demonstrated a novel continuous process for assembling targeting ligands, peptidic spacers, fluorescent tags and a chelating core for the attachment of cytotoxic molecules, radiotracers, nanomaterials in a standard Fmoc solid-phase peptide synthesis in high yield and purity. The differentially prot...
Data
NMR and HRMS spectra of compounds 3, 4 and analytical HPLC spectra of purified (λ at 254 nm and 225 nm) as well as crude (λ at 225 nm), electrospray ionization mass spectra and high-resolution mass spectra for bioconjugates 13 and 17.
Article
Mercury, a highly toxic contaminant is a detrimental environmental pollutant that causes severe health problems in human beings and developing an economical, rapid, and efficient technique for determination of Hg²⁺ ions at low concentrations remains a challenge. Herein, we report the preparation and application of orange-red luminescent Se doped Zn...
Article
The development of small molecule ligand-targeted therapeutics is currently of paramount importance for treatment of cancer due to their potential to reduce system toxicity and increase potency of a delivered chemotherapeutic drug. The main aim of a targeted drug-delivery technique is to release the drug cargo selectively into tumor tissues, avoidi...
Article
Present treatment strategies focus on minimizing unwanted toxicity to healthy cells during chemotherapeutic treatment. This is achieved by developing strategies to selectively deliver drugs to malignant cells over‐expressing specific protein biomarkers. The drugs are attached via a self‐immolative linker to a small molecule homing ligand having aff...
Article
Although peptides, antibodies/antibody fragments, siRNAs, antisense DNAs, enzymes and aptamers are all under development as possible therapeutic agents, the breadth of their applications has been severely compromised by their inability to reach intracellular targets. Thus, while macromolecules can often enter cells by receptor-mediated endocytosis,...
Article
Full-text available
Almost all cells are easily killed by exposure to potent oxidants. Indeed, major pathogen defense mechanisms in both animal and plant kingdoms involve production of an oxidative burst, where host defense cells show an invading pathogen with reactive oxygen species (ROS). Although cancer cells can be similarly killed by ROS, development of oxidant-p...
Article
The vast majority of nanomedicine research is focused on the use of nanoparticles for the diagnosis and treatment of cancer. However, the dense extracellular matrix of solid tumors restricts nanoparticle penetration, raising the question of whether the best applications of nanomedicines lie in oncology. In this study, the uptake of folate-conjugate...
Article
We demonstrate the in vivo imaging of a mouse tumor using fluorescence optical diffusion tomography and the extraction of kinetic information from a compartment model, yielding the first folate drug release kinetics inside cancer cells.
Article
Many cancer cells over-express folate receptors, and this provides an opportunity for both folate-targeted fluorescence imaging and the development of targeted anti-cancer drugs. We present an optical imaging modality that allows for the monitoring and evaluation of drug delivery and release through disulfide bond reduction inside a tumor in vivo f...
Conference Paper
We present a folate-targeting fluorophore pair that has the potential for imaging targeted anticancer drug delivery kinetics. Experimental results for in vivo imaging of absorption and fluorescence in a small animal are presented.
Article
Despite the broad impact in medicine that optics can bring, thus far practical approaches are limited to weak scatter or near-surface monitoring. We show a method that utilizes a laser topography scan and a diffusion equation model to describe the photon transport, together with a multiresolution unstructured grid solution to the nonlinear optimiza...
Article
Pro-inflammatory macrophages play a prominent role in such autoimmune diseases as rheumatoid arthritis, Crohn's disease, psoriasis, sarcoidosis, and atherosclerosis. Because pro-inflammatory macrophages have also been shown to overexpress a receptor for the vitamin folic acid (i.e., folate receptor beta; FR-β), folate-linked drugs have been explore...
Article
Complete surgical resection of malignant disease is the only reliable method to cure cancer. Unfortunately, quantitative tumor resection is often limited by a surgeon's ability to locate all malignant disease and distinguish it from healthy tissue. Fluorescence-guided surgery has emerged as a tool to aid surgeons in the identification and removal o...
Conference Paper
The delivery and release of folate-targeted anti-cancer drugs has been largely unknown, inhibiting drug development. We show how to access this information and illustrate this with in vivo mouse images of fluorophore pair release kinetics.
Article
Folic acid has been frequently exploited to target attached drugs to cells that overexpress a folate receptor (FR). Unfortunately, folic acid and folate-linked drugs bind equally well to both major isoforms of the FR-that is, FR-α, which is primarily expressed on malignant cells, and FR-β, which is upregulated on activated monocytes and macrophages...
Article
The vitamin folic acid has been extensively utilized to target chemotherapeutic and imaging agents to cancer cells that over-express a folate receptor (FR).¹⁻² Importantly, both folic acid and conjugates of folic acid bind with similar affinity to the two major isoforms of FR; i.e. FR-α which is primarily expressed on tumor cells and FR-β that is u...
Article
We describe an approach for the evaluation of targeted anti-cancer drug delivery in vivo. The method emulates the drug release and activation process through acceptor release from a targeted donor-acceptor pair that exhibits fluorescence resonance energy transfer (FRET). In this case, folate targeting of the cancer cells is used - 40 % of all human...
Conference Paper
An imaging method that utilizes a laser topography scan and a multigrid reconstruction based on a diffusion model avoids the scattering emulsion background. Image reconstructions for a tissue phantom and fluorescence in a mouse are shown.
Article
We present experimental results for reconstructing physiologically relevant optical properties of a small animal using optical diffusion tomography.

Citations

... Therefore, this needs to be further investigated in the future. As the basic sites and strength of the catalyst plays the main role in catalyzing transesterification, CeO 2 obtained from the final pH = 4 provided higher % FAME than those obtained from the final pH = 3 and 2, as seen in Table S1 [8][9][10]. It was noted that 30.5% FAME obtained from CeO 2 at pH = 4 was quite low because the reaction time was shorter, compared to the condition used in the manuscript, in order to clearly observe the difference of %FAME. ...
... The PL is due to the presence of defects in the Se doped ZnO nanorods. A detailed characterization of Se doped ZnO sample for Se incorporation, defects generation and optical properties by XRD, XPS and PL were reported by our research group [24,25]. In brief, the approaches for producing oxygen defects in Se doped ZnO were described and included in the Supporting Information. ...
... The synthesis of bioactive natural products, key intermediates, and drug candidates from pyridine and its derivatives has attracted increasing intrestes [26][27][28]. Synthesis of azaindoles and azaindole derivatives, which yielded several therapeutic agents for various diseases [29][30][31][32] from pyridine derivatives, has been recently extensively studied [33][34][35][36]. The synthesis route of substituted azaindoles from nitropyridines has been reported [37][38][39][40][41]. ...
... Ki values of the three samples were calculated according to linear regression of logarithmic concentration and effect. As shown in Table 2, the Ki value of PSMA-1 was 2.4 nM, which was within the same order of magnitude as some of the PSMA monoclonal antibodies (3/A12 mAb 2nM binding affinity to the extracellular domain of PSMA in LNCap cells) [45]. The modification of the protecting group of ε amine of lysine resulted in a slight compromise of the inhibitory activity [28]. ...
... These were mostly related to various synthetic efforts to invent and improve the conjugation techniques without any biological tests (43)(44)(45). Various other basically rare biomedical applications, including facilitated blood−brain barrier transport (46), biotechnological applications like DNA cleavage (47), radiolabeling (48), imaging (49) or chelation were published too (50). For the sake of the database, these are valuable entries, because these appreciate the more diverse applicability of peptide conjugates and also provide useful insight to synthetic solutions for interested organic chemists. ...
... There are many points relating to aspects of frontiers in science. Some issues of papers that we list here but do not comment on involve nanoparticle, CdSe materials, cancer cells, Cu(In,Ga)Se 2 materials, zinc selenite coatings with GSH, water solubility, fluorescent and electrochemical methods, CdSe/ZnS thioglycolic acid coatings, physicochemical characterization, Beta lactoglobulin levels, O 2− and Cu 2+ detection, dimercaprol-capped QD systems, hydrodynamic radii, confocal fluorescent selenous acid, etc; These and many more topics have been central in previous reports (see references [104][105][106][107][108][109][110][111][112][113][114][115][116], (Figure 61), [117,118], (Figure 62), [119] (Figure 63), [120][121][122][123][124][125][126][127][128][129]). topics have been central in previous reports (see references [104][105][106][107][108][109][110][111][112][113][114][115][116], (Figure 61), [117,118], (Figure 62), [119] (Figure 63), [120][121][122][123][124][125][126][127][128][129] Karimi et al. synthesized carbon nanotube-cadmium selenide nanocomposites by electrophoretic deposition. ...
... While targeted endosomal delivery of siRNA conjugates with nigericin, a hydrophobic ionophore that catalyzes the exchange of K + for H + , can enhance endosomal escape, it does so by bursting the entire endosome [34,35], which is not a clinically acceptable path forward. Overall, due to the uncontrollable problem of hitting many endosomes in many cell types and tissues, regardless of whether or not they contain RNA therapeutic cargo, we do not foresee a clinical development path going forward for using small-molecule endolytic agents, especially those whose mechanism of action results in endosomal bursting and release of the entire endosomal contents into the cytoplasm. ...
... Previous studies showed that substantial folate receptor (FR)-positive macrophages infiltrated into human inflamed colon during IBD [74]. Moreover, folate-functionalized nanoparticles could target FR on macrophages in inflamed colon via systemic and oral routes [75][76][77]. These attempts to target inflammatory macrophages have been well validated and used for treatment in animal models of IBD or in living specimens of patients with IBD. ...
... Another highly expressed molecule found on macrophages is the folic acid receptor, which draws extensive attention and is modified on the surface of FITC-MTX-contained PLGA nanoparticle. Subsequently, a concentration of FITC fluorescence was observed residing in the joint, demonstrating a significant targeting effect [233]. Similarly, polypeptides, antibodies, and metal nanoclusters Fig. 9. Schematic illustration of immune disorders and other target organs of RA. ...
... These researches help them to discover, the very interesting role of quinone compounds. They are often found in biological systems such as photosynthetic or enzymatic systems, and in chemistry (oxidation, conductive polymers, etc.) [2] [3] [4]. These molecules are present in many structures with high antitumoral potential [5] [6] [7] [8] [9]. ...