Publications by authors named "Shanmughan Shamjith"

The practical application of photodynamic therapy (PDT) demands targeted and activatable photosensitizers to mitigate off-target phototoxicity common in "always on" photosensitizers during light exposure. Herein, a cyclometalated iridium complex-based activatable photodynamic molecular hybrid, Cy-Ir-7-nitrobenzofurazan (NBD), is demonstrated as a biomedicine for molecular precision. This design integrates a hydrogen sulfide (HS)-responsive NBD unit with a hydroxy-appended iridium complex, Cy-Ir-OH.

View Article and Find Full Text PDF

The increased energy demands inherent in cancer cells necessitate a dependence on mitochondrial assistance for their proliferation and metastatic activity. Herein, an innovative photo-medical approach has been attempted, specifically targeting mitochondria, the cellular powerhouses, to attain therapeutic benefit. This strategy facilitates the rapid and precise initiation of apoptosis, the programmed cell death process.

View Article and Find Full Text PDF

Photodynamic therapy (PDT) has emerged as an efficient and noninvasive treatment approach utilizing laser-triggered photosensitizers for combating cancer. Within this rapidly advancing field, iridium-based photosensitizers with their dual functionality as both imaging probes and PDT agents exhibit a potential for precise and targeted therapeutic interventions. However, most reported classes of Ir(III)-based photosensitizers comprise mononuclear iridium(III), with very few examples of dinuclear systems.

View Article and Find Full Text PDF

Cocultivation of combinations of Streptomyces species isolated from the same soil was explored to isolate novel secondary metabolites. Recently, we reported the isolation of a novel vicinal diepoxide of alloaureothin along with three carboxamides, 4-aminobenzoic acid, and 1,6-dimethoxyphenazine from the individual culture of Streptomyces luteireticuli NIIST-D31. Herein, cocultivation of NIIST-D31 with Streptomyces luteoverticillatus NIIST-D47 afforded two new stereochemical variants of streptophenazine (S1 and S2), and 1-N-methylalbonoursin, where the individual culture of NIIST-D47 primarily produced carbazomycins A, D, and E.

View Article and Find Full Text PDF

Discovery of the biological signaling roles of HS has spurred great interest in developing reliable methods for its accurate detection and quantification. As considerable variation in its levels is seen during pathological conditions such as sepsis, real-time quantification methods have relevance in diagnosis as well. Of various approaches, reaction-based probes which respond through 'off-on' fluorescence emission remain the most studied.

View Article and Find Full Text PDF

The nicotinamide adenine dinucleotide-reduced (NADH) function as a hydride (H) carrier to maintain cellular homeostasis. Herein, we report a quinoline appended iridium complex (QAIC) as a molecular probe in fluorescence and surface-enhanced Raman spectroscopy (SERS) modalities to evaluate the endogenous NADH status. NADH-triggered activation of QAIC enabled luminescence (turn-ON) and SERS (turn-OFF) switching phenomenon with a detection limit of 25.

View Article and Find Full Text PDF

Pancreatic cancer represents one of the most aggressive in nature with a miserable prognosis that warrants efficient diagnostic and therapeutic interventions. Herein, a MnO overlaid gold nanoparticle (AuNPs) based photothermal theranostic nanoenvelope (PTTNe:MnO@AuNPs) was fabricated to substantiate surface-enhanced Raman spectroscopy (SERS) guided real-time monitoring of photothermal therapy (PTT) in pancreatic cancer cells. A sharp enhancement of the fingerprint Raman signature of MnO at 569 cm exhibited as a marker peak for the first time to elucidate the intracellular PTT event.

View Article and Find Full Text PDF

Recent advancements in a nanoarchitecture platform for safe and effective targeted phototherapy in a synergistic fashion is an absolute necessity in localized cancer therapy. Photothermal and photodynamic therapies (PTT and PDT) are considered as the most promising localized therapeutic intervention for cancer management as they have no long-term side effects and are minimally invasive and affordable. Herein, we have demonstrated a tailor-made nanotheranostic probe in which macrocyclic host cucurbituril [8] (CB[8]) is placed as a glue between two gold nanorods (GNRs) within ∼3 nm gaps in linear nanoassemblies with exquisitely sensitive plasmonics that exert combined phototherapy to investigate the therapeutic progression on human breast cancer cells.

View Article and Find Full Text PDF

In accordance with the recent studies, Raman spectroscopy is well experimented as a highly sensitive analytical and imaging technique in biomedical research, mainly for various disease diagnosis including cancer. In comparison with other imaging modalities, Raman spectroscopy facilitate numerous assistances owing to its low background signal, immense spatial resolution, high chemical specificity, multiplexing capability, excellent photo stability and non-invasive detection capability. In cancer diagnosis Raman imaging intervened as a promising investigative tool to provide molecular level information to differentiate the cancerous vs non-cancerous cells, tissues and even in body fluids.

View Article and Find Full Text PDF

Effective treatment of malignant melanoma requires an appropriate combination of therapeutic intervention with long-term prognosis as it often survives by monotherapies. Herein, we report a novel melanoma-targeted theranostic nanoenvelope (MTTNe: ISQ@BSA-AuNC@AuNR@DAC@DR5) which has been constructed by assembling a bovine serum albumin (BSA) stabilized gold nanocluster on a gold nanorod (BSA-AuNC@AuNR), a three-in-one theranostic modality, i.e.

View Article and Find Full Text PDF