Targeted Theranostic Nano Vehicle Endorsed with Self-Destruction and Immunostimulatory Features to Circumvent Drug Resistance and Wipe-Out Tumor Reinitiating Cancer Stem Cells.

The downsides of conventional cancer monotherapies are profound and enormously consequential, as drug-resistant cancer cells and cancer stem cells (CSC) are typically not eliminated. Here, a targeted theranostic nano vehicle (TTNV) is designed using manganese-doped mesoporous silica nanoparticle with an ideal surface area and pore volume for co-loading an optimized ratio of antineoplastic doxorubicin and a drug efflux inhibitor tariquidar. This strategically framed TTNV is chemically conjugated with folic acid and hyaluronic acid as a dual-targeting entity to promote folate receptor (FR) mediated cancer cells and CD44 mediated CSC uptake, respectively. Interestingly, surface-enhanced Raman spectroscopy is exploited to evaluate the molecular changes associated with therapeutic progression. Tumor microenvironment selective biodegradation and immunostimulatory potential of the MSN-Mn core are safeguarded with a chitosan coating which modulates the premature cargo release and accords biocompatibility. The superior antitumor response in FR-positive syngeneic and CSC-rich human xenograft murine models is associated with a tumor-targeted biodistribution, favorable pharmacokinetics, and an appealing bioelimination pattern of the TTNV with no palpable signs of toxicity. This dual drug-loaded nano vehicle offers a feasible approach for efficient cancer therapy by on demand cargo release in order to execute complete wipe-out of tumor reinitiating cancer stem cells.

Diagnostic spectro-cytology revealing differential recognition of cervical cancer lesions by label-free surface enhanced Raman fingerprints and chemometrics.

Herein we have stepped-up on a strategic spectroscopic modality by utilizing label free ultrasensitive surface enhanced Raman scattering (SERS) technique to generate a differential spectral fingerprint for the prediction of normal (NRML), high-grade intraepithelial lesion (HSIL) and cervical squamous cell carcinoma (CSCC) from exfoliated cell samples of cervix. Three different approaches i.e. single-cell, cell-pellet and extracted DNA from oncology clinic as confirmed by Pap test and HPV PCR were employed. Gold nanoparticles as the SERS substrate favored the increment of Raman intensity exhibited signature identity for Amide III/Nucleobases and carotenoid/glycogen respectively for establishing the empirical discrimination. Moreover, all the spectral invention was subjected to chemometrics including Support Vector Machine (SVM) which furnished an average diagnostic accuracy of 94%, 74% and 92% of the three grades. Combined SERS read-out and machine learning technique in field trial promises its potential to reduce the incidence in low resource countries.

Chloroform as a carbon monoxide source in palladium-catalyzed synthesis of 2-amidoimidazo[1,2-a]pyridines.

A palladium-catalyzed aminocarbonylation strategy exploiting chloroform as a CO source has been developed for the synthesis of biologically potent 2-amidoimidazopyridine scaffolds. The aminocarbonylation reaction was found to be general with a range of amines and substituted imidazopyridines. Preliminary biological evaluation of cytotoxicity on selected examples provides scope for future investigations.

Emergence of Gold-Mesoporous Silica Hybrid Nanotheranostics: Dox-Encoded, Folate Targeted Chemotherapy with Modulation of SERS Fingerprinting for Apoptosis Toward Tumor Eradication.

Strategically fabricated theranostic nanocarrier delivery system is an unmet need in personalized medicine. Herein, this study reports a versatile folate receptor (FR) targeted nanoenvelope delivery system (TNEDS) fabricated with gold core silica shell followed by chitosan-folic acid conjugate surface functionalization by for precise loading of doxorubicin (Dox), resembled as Au@SiO2 -Dox-CS-FA. TNEDS possesses up to 90% Dox loading efficiency and internalized through endocytosis pathway leading to pH and redox-sensitive release kinetics. The superior FR-targeted cytotoxicity is evaluated by the nanocarrier in comparison with US Food and Drug Administration (FDA)-approved liposomal Dox conjugate, Lipodox. Moreover, TNEDS exhibits theranostic features through caspase-mediated apoptosis and envisages high surface plasmon resonance enabling the nanoconstruct as a promising surface enhanced Raman scattering (SERS) nanotag. Minuscule changes in the biochemical components inside cells exerted by the TNEDS along with the Dox release are evaluated explicitly in a time-dependent fashion using bimodal SERS/fluorescence nanoprobe. Finally, TNEDS displays superior antitumor response in FR-positive ascites as well as solid tumor syngraft mouse models. Therefore, this futuristic TNEDS is expected to be a potential alternative as a clinically relevant theranostic nanomedicine to effectively combat neoplasia.

Computational and mechanistic studies on the effect of galactoxyloglucan: Imatinib nanoconjugate in imatinib resistant K562 cells.

Imatinib mesylate, a BCR/ABL fusion protein inhibitor, is the first-line treatment against chronic myelogenous leukemia. In spite of its advantageous viewpoints, imatinib still has genuine impediments like undesirable side effects and tumor resistance during chemotherapy. Nanoparticles with sustainable release profile will help in targeted delivery of anticancer drugs while minimizing deleterious side effects and drug resistance. The use of biopolymers like galactoxyloglucan (PST001) for the fabrication of imatinib mesylate nanoparticles could impart its use in overcoming multidrug resistance in chronic myelogenous leukemia patients with minimal side effects. This study involved in the synthesis of PST-Imatinib nanoconjugates with appreciable drug payload and excellent cytotoxicity against drug-resistant chronic myelogenous leukemia cell line (K562) in comparison with free drug. The use of bioinformatics tool revealed better binding affinity for the drug-polysaccharide complex than the drug alone with three proteins: 3QX3 (Topoisomerase), 1M17 (EGFR tyrosine kinase domain), and 3QRJ (ABL1 kinase domain). Assessment of the biochemical, hematological, and histopathological parameters in mice upheld the security and adequacy of the nanoconjugate compared to free drug. Although perspective investigations are warranted, in a condition like drug resistance in leukemia, this nanoconjugate would display a productive approach in cancer therapeutics.

A Ratiometric Near-Infrared Fluorogen for the Real Time Visualization of Intracellular Redox Status during Apoptosis.

Direct monitoring of apoptotic progression is a major step forward for the early assessment of therapeutic efficacy of certain treatments and the accurate evaluation of the spread of a disease. Here, the regulatory role of glutathione (GSH) is explored as a potential biomarker for tracking apoptosis. For this purpose, a near- infrared (NIR) squaraine dye is introduced that is capable of sensing GSH in a ratiometric manner by switching its emission from NIR (690 nm) to visible region (560 nm). The favorable biocompatible attributes of the probe facilitated the real-time monitoring of apoptotic process in line with the conventional apoptotic assay. Furthermore, the robust nature of the probe was utilized for the quantitative estimation of GSH during different stages of apoptosis. Through this study, an easy and reliable method of assaying apoptosis is demonstrated, which can provide valuable insights in translational clinical research.

Plasmonically Enhanced Galactoxyloglucan Endowed Gold Nanoparticles Exposed Tumor Targeting Biodistribution Envisaged in a Surface-Enhanced Raman Scattering Platform.

Biopolymer-capped gold nanoparticles (AuNPs) were perceived for tracing biodistribution in a solid tumor mice through surface-enhanced Raman scattering (SERS) fingerprinting. In this strategy, a robust and ecofriendly green chemistry approach was adopted to construct galactoxyloglucan (PST001) endowed AuNPs (PST-GNPs) with cancer-cell-selective toxic nature and excellent biocompatibility. Plasmonically enhanced light-scattering properties facilitated PST-GNPs to be a superior SERS substrate with high Raman signal enhancement. In this context, PST-GNPs were scrutinized for the noninvasive label-free SERS live-cell spectral imaging to evaluate the fingerprint molecular details of cellular processes. Consequently, the inherent SERS feature of PST-GNPs enabled us to investigate the dynamic and complex nature with NP biodistrubution in tumor-bearing mice on a SERS platform that illustrated the tumor targeting nature. Henceforth, the present findings emphasized a futuristic clinically relevant scenario for tracing the in vivo NP dissemination in a label-free fashion for providing vital biochemical details on a molecular level.

Bisindole-oxadiazole hybrids, T3P® -mediated synthesis, and appraisal of their apoptotic, antimetastatic, and computational Bcl-2 binding potential.

In the pursuit of novel anticancer leads, new bisindole-oxadiazoles were synthesized using propyl phosphonic anhydride as a mild and efficient reagent. The molecule, 3-[5-(1H-indol-3-ylmethyl)-1,3,4-oxadiazol-2-yl]-1H-indole (3a) exhibited selective cytotoxicity to MCF-7 cells with a cell cycle arrest in the G1 phase. The mechanism of cytotoxicity of 3a involved caspase-2-dependent apoptotic pathway with characteristic apoptotic morphological alterations as observed in acridine orange/ethidium bromide and Hoechst staining. The wound healing migratory assay exhibited an intense impairment in the motility of MCF-7 cells on incubation with 3a. Docking simulations with anti-apoptotic protein Bcl-2, which is also involved in cancer metastasis displayed good affinity and high binding energy of 3a into the well characterized BH3 binding site. The positive correlation between the Bcl-2 binding studies and the results of in vitro investigations exemplifies compound 3a as a lead molecule exhibiting MCF-7 differential cytotoxicity via apoptotic mode of cell death in addition to its anti-metastatic activity.

HER2 siRNA Facilitated Gene Silencing Coupled with Doxorubicin Delivery: A Dual Responsive Nanoplatform Abrogates Breast Cancer.

The present study investigated the concurrent delivery of antineoplastic drug, doxorubicin, and HER2 siRNA through a targeted theranostic metallic gold nanoparticle designed using polysaccharide, PSP001. The as-synthesized HsiRNA@PGD NPs were characterized in terms of structural, functional, physicochemical, and biological properties. HsiRNA@PGD NPs exposed adequate hydrodynamic size, considerable ζ potential, and excellent drug/siRNA loading and encapsulation efficiency. Meticulous exploration of the biocompatible dual-targeted nanoconjugate exhibited an appealing biocompatibility and pH-sensitive cargo release kinetics, indicating its safety for use in clinics. HsiRNA@PGD NPs deciphered competent cancer cell internalization, enhanced cytotoxicity mediated via the induction of apoptosis, and excellent downregulation of the overexpressing target HER2 gene. Further in vivo explorations in the SKBR3 xenograft breast tumor model revealed the appealing tumor reduction properties, selective accumulation in the tumor site followed by significant suppression of the HER2 gene which contributed to the exclusive abrogation of breast tumor mass by the HsiRNA@PGD NPs. Compared to free drugs or the monotherapy constructs, the dual delivery approach produced a synergistic suppression of breast tumors both in vitro and in vivo. Hence the drawings from these findings implicate that the as-synthesized HsiRNA@PGD NPs could offer a promising platform for chemo-RNAi combinational breast cancer therapy.

Isolation of two new stereochemical variants of streptophenazine by cocultivation of Streptomyces NIIST-D31, Streptomyces NIIST-D47, and Streptomyces NIIST-D63 strains in 3C2 combinations.

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. The new streptophenazines and 1-N-methylalbonoursin were also observed during cocultivation of NIIST-D31 with Streptomyces thioluteus NIIST-D63, where the individual culture of NIIST-D63 strain afforded for the first time 2,2'-bipyridines (caerulomycinamide and dipyrimicin B), picolinamide, 2,3-dimethoxybenzamide, 2-hydroxy-3-methoxybenzamide, and 6-amino-2-pyridone along with known natural products aureothin and 1,6-dimethoxyphenazine. Finally, cocultivation of NIIST-D47 and NIIST-D63 strains produced carbazomycins B and C, alloaureothin, cyclo-(Leu-Pro), investiamide, and 4-aminobenzoic acid. Some of the compounds observed in the individual cultures were also produced in cocultivations. Improvement in the yield of secondary metabolites during cocultivation compared to individual culturing is well-known, which is noted here for vicinal diepoxide of alloaureothin. The production of new streptophenazines by cocultivation combinations with NIIST-D31 suggests that NIIST-D47 and NIIST-D63 may function as inducers in activating cryptic secondary metabolite-biosynthetic gene clusters. Cytotoxicity of the new streptophenazines in cancerous (MCF7 and MDA-MB-231) or non-cancerous (WI-38) cells were tested, however, they exhibited no significant activity.

Antitumor and immunopotentiating activity of polysaccharide PST001 isolated from the seed kernel of Tamarindus indica: an in vivo study in mice.

Antitumor activity of polysaccharide PST001 isolated from the seed kernel of Tamarindus indica was evaluated using different cancer cell lines. Human cancer cell lines A549, KB, and MCF-7 and murine cancer cell lines DLA and EAC were treated with PST001 and cell growth inhibition was assessed by MTT assay. In vivo studies were carried out for toxicity, tumor reduction and immunomodulation. The respective IC(50) of PST001 in A549, KB, and DLA was at 80.72, 190.99, and 91.14 µg/mL. Significant tumor reduction was obtained in both DLA and EAC tumors on treatment with PST001 which was more prominent when PST001 was administered with CTX/5-fluorouracil. Increase in total WBC, CD4(+) T-cell population, and bone marrow cellularity suggested strong immunomodulatory activity for this compound. No significant abnormality was observed in toxicity studies. Thus the results of the present study suggest that PST001 has immunomodulatory and tumor inhibitory activities and has the potential to be developed as an anticancer agent and immunomodulator either as a sole agent or as an adjuvant to other chemotherapeutic drugs.

Elucidating cell surface glycan imbalance through SERS guided metabolic glycan labelling: An appraisal of metastatic potential in cancer cells.

The intrinsic complexities of cell-surface glycans impede tracking the metabolic changes in cells. By coupling metabolic glycan labelling (MGL) and surface-enhanced Raman scattering (SERS), we employed the MGL-SERS strategy to elucidate the differential glycosylation pattern in cancer cell lines. Herein, for the first time, we are reporting an N-alkyl derivative of glucosamine (GlcNPhAlk) as a glycan labelling precursor. The extent of labelling was assessed by utilizing Raman imaging and verified by complementary fluorescence and Western blot analysis. MGL-SERS technique was implemented for a comparative evaluation of cell surface glycan imbalance in different cancer cells wherein a linear relationship between glycan expression and metastatic potential was established. Further, the effect of sialyltransferase inhibitor, P-3Fax-Neu5Ac, on metabolic labelling of GlcNPhAlk proved the incorporation of GlcNPhAlk to the terminal glycans through the sialic acid biosynthetic pathway. Hence, this methodology unveils the phenomenon of metastatic progression in cancer cells with inherent glycosylation-related dysplasia.

NADH-depletion triggered energy shutting with cyclometalated iridium (III) complex enabled bimodal Luminescence-SERS sensing and photodynamic therapy.

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 25.6 nM and 15 pM for NADH in luminescence and SERS respectively. Transition state modelling using density functional theory calculations proved that a facile migration of H from NADH to QAIC transformed the activated QAIC (N-QAIC) with an energy span of 19.7 kcal/mol. Furthermore, N-QAIC is probed as a photosensitizer to source singlet oxygen by blocking the photo induced electron transfer (PeT) and generate NAD radicals. Therefore, an efficient light triggered cyclometalated iridium-based molecular probe has been divulged to promote bimodal NADH sensing and multiphase photodynamic therapy.

IndiFluors: A New Full-Visible Color-Tunable Donor-Acceptor-Donor (D1-A-D2) Fluorophore Family for Ratiometric pH Imaging during Mitophagy.

Full-visible color-tunable new fluorophores are essential in bioimaging research. However, it is significantly challenging to design fluorophores with the desired optical and biological properties owing to their structural complexity. We report a unified design of an interesting molecular framework, IndiFluors, based on the principle of a donor-acceptor-donor (D1-A-D2) system. The IndiFluors comprise pyrylium, pyridinium, and pyridine derivatives, which exhibit full-visible emission color (375-700 nm) by varying donor and acceptor strengths of the core scaffolds. With a minimal change of structure, the bright fluorophores (Φ: 0.96) can be tuned to become nonfluorescent (Φ: 0.01), which is well explained by time-dependent density functional theory (TD-DFT/PCM) by oscillator strengths in the S1 state. Within IndiFluors, pyridinium offers several advantages, including a large Stokes shift (∼154 nm) and excellent stability, compared to pentacyclic pyrylium fluorophores. Especially, the designed probe, PM-Mito-OH, demonstrated specific colocalization in mitochondria and a monitored ratiometric pH change during mitochondrial damage, autolysosomes, and the mitophagy process. Hence, IndiFluors and the derived probe show great potential for cellular pH imaging in live cells while exhibiting minimal cytotoxicity.

A non-invasive ultrasensitive diagnostic approach for COVID-19 infection using salivary label-free SERS fingerprinting and artificial intelligence.

Clinical diagnostics for SARS-CoV-2 infection usually comprises the sampling of throat or nasopharyngeal swabs that are invasive and create patient discomfort. Hence, saliva is attempted as a sample of choice for the management of COVID-19 outbreaks that cripples the global healthcare system. Although limited by the risk of eliciting false-negative and positive results, tedious test procedures, requirement of specialized laboratories, and expensive reagents, nucleic acid-based tests remain the gold standard for COVID-19 diagnostics. However, genetic diversity of the virus due to rapid mutations limits the efficiency of nucleic acid-based tests. Herein, we have demonstrated the simplest screening modality based on label-free surface enhanced Raman scattering (LF-SERS) for scrutinizing the SARS-CoV-2-mediated molecular-level changes of the saliva samples among healthy, COVID-19 infected and COVID-19 recovered subjects. Moreover, our LF-SERS technique enabled to differentiate the three classes of corona virus spike protein derived from SARS-CoV-2, SARS-CoV and MERS-CoV. Raman spectral data was further decoded, segregated and effectively managed with the aid of machine learning algorithms. The classification models built upon biochemical signature-based discrimination method of the COVID-19 condition from the patient saliva ensured high accuracy, specificity, and sensitivity. The trained support vector machine (SVM) classifier achieved a prediction accuracy of 95% and F1-score of 94.73%, and 95.28% for healthy and COVID-19 infected patients respectively. The current approach not only differentiate SARS-CoV-2 infection with healthy controls but also predicted a distinct fingerprint for different stages of patient recovery. Employing portable hand-held Raman spectrophotometer as the instrument and saliva as the sample of choice will guarantee a rapid and non-invasive diagnostic strategy to warrant or assure patient comfort and large-scale population screening for SARS-CoV-2 infection and monitoring the recovery process.

Elucidating Gold-MnO2 Core-Shell Nanoenvelope for Real Time SERS-Guided Photothermal Therapy on Pancreatic Cancer Cells.

Pancreatic cancer represents one of the most aggressive in nature with a miserable prognosis that warrants efficient diagnostic and therapeutic interventions. Herein, a MnO2 overlaid gold nanoparticle (AuNPs) based photothermal theranostic nanoenvelope (PTTNe:MnO2@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 MnO2 at 569 cm-1 exhibited as a marker peak for the first time to elucidate the intracellular PTT event. In this strategic design, the leftover bare AuNPs after the degradation of the MnO2 layer from the nanoenvelope in the presence of intracellular H2O2 enabled real-time tracking of biomolecular changes of Raman spectral variations during PTT. Moreover, the surface of the as-synthesized nanoenvelope was functionalized with a pancreatic cancer cell targeting peptide sequence for cholecystokinin fashioned the PTTNe with admirable stability and biocompatibility. Finally, the precise cell death mechanism was explicitly assessed by SERS spectral analysis as a complementary technique. This targeted phototheranostic approach demonstrated in pancreatic cancer cells presented a therapeutically viable prototype for futuristic personalized cancer nanomedicine.

Amphiphilic fluorescent probe self-encored in plasma to detect pH fluctuations in cancer cell membranes.

We have developed an amphiphilic pH probe (P1CS) to detect pH levels in the plasma membrane in cancer cells. An elevated fluorescence signal at 550 nm at the cell surface of cancer cells (MDA-MB-231, HeLa cells) prompted the application of P1CS as a pH marker for the cancer cell surface, discriminating it from normal cells (WI-38). Moreover, the probe enables labeling of the surface of multilayered tumor spheroids, which promotes its use as a marker for the surface of tumor tissue.

A single benzene fluorescent probe for efficient formaldehyde sensing in living cells using glutathione as an amplifier.

Formaldehyde (FA), a simple reactive carbonyl molecule, is endogenously produced in the cell at various physiological condition. At elevated level, FA causes severe cell toxicity as well as damage in macromolecules such proteins and DNA. For detecting FA in living cell, we identify a small but effective fluorescent turn on probe comprising single benzene-based orothophenylenediamine compound. Further study reveals that carboxylic group in orothophenylenediamine plays the important role in enhancing fluorescent signal than another electron withdrawing group. It is even interesting to observe the occurrence of fluorescent enhancement in glutathione (GSH) environment which is generally abundant in every cell. Our probe enables to detect FA over other bio-analytes efficiently with limit of detection of 123 nM and 355-fold of enhancement in cellular mimicking conditions. Moreover, this probe could be useful in discriminating cell that has high concentration of FA as well as GSH.

Dynamic self-assembly of mannosylated-calix[4]arene into micelles for the delivery of hydrophobic drugs.

Carbohydrate-lectin interactions and glycol-molecule-driven self-assembly are powerful yet challenging strategies to create supramolecular nanostructures for biomedical applications. Herein, we develop a modular approach of micellization with a small molecular mannosylated-calix[4]arene synthetic core, CA4-Man3, to generate nano-micelles, CA4-Man3-NPs, which can target cancer cell surface receptors and facilitate the delivery of hydrophobic cargo. The oligomeric nature of the calix[4]arene enables the dynamic self-assembly of calix[4]arene (CA4), where an amphiphile, functionalized with mannose units (CA-glycoconjugates) in the upper rim and alkylated lower rim, afforded the CA4-Man3-NPs in a controllable manner. The presence of thiourea units between calixarene and tri-mannose moiety facilitated the formation of a stable core with bidentate hydrogen bonds, which in turn promoted mannose receptor targeted uptake and helped in the intracellular pH-responsive release of antineoplastic doxorubicin (Dox). Physiochemical features including the stability of the nanomicelle could circumvent the undesirable leakage of the cargoes, ensuring maximum therapeutic output with minimum off-targeted toxicity. Most importantly, surface-enhanced Raman scattering (SERS) was utilized for the first time to evaluate the critical micelle concentration during the formation, cellular uptake and intracellular drug release. The present study not only provides an architectural design of a new class of organic small molecular nanomicelles but also unveils a robust self-assembly approach that paves the way for the delivery of a wide range of hydrophobic chemotherapeutic drugs.