Enzymatic depletion of circulating glutamine is immunosuppressive in cancers.

Although glutamine addiction in cancer cells is extensively reported, there is controversy on the impact of glutamine metabolism on the immune cells within the tumor microenvironment (TME). To address the role of extracellular glutamine, we enzymatically depleted circulating glutamine using PEGylated Helicobacter pylori gamma-glutamyl transferase (PEG-GGT) in syngeneic mouse models of breast and colon cancers. PEG-GGT treatment inhibits growth of cancer cells in vitro, but in vivo it increases myeloid-derived suppressor cells (MDSCs) and has no significant impact on tumor growth. By deriving a glutamine depletion signature, we analyze diverse human cancers within the TCGA and illustrate that glutamine depletion is not associated with favorable clinical outcomes and correlates with accumulation of MDSC. Broadly, our results help clarify the integrated impact of glutamine depletion within the TME and advance PEG-GGT as an enzymatic tool for the systemic and selective depletion (no asparaginase activity) of circulating glutamine in live animals.

An intranasal nanoparticle vaccine elicits protective immunity against Mycobacterium tuberculosis.

Mucosal vaccines have the potential to elicit protective immune responses at the point of entry of respiratory pathogens, thus preventing even the initial seed infection. Unlike licensed injectable vaccines, mucosal vaccines comprising protein subunits are only in development. One of the primary challenges associated with mucosal vaccines has been identifying and characterizing safe yet effective mucosal adjuvants that can effectively prime multi-factorial mucosal immunity. In this study, we tested NanoSTING, a liposomal formulation of the endogenous activator of the stimulator of interferon genes (STING) pathway, cyclic guanosine adenosine monophosphate (cGAMP), as a mucosal adjuvant. We formulated a vaccine based on the H1 antigen (fusion protein of Ag85b and ESAT-6) adjuvanted with NanoSTING. Intranasal immunization of NanoSTING-H1 elicited a strong T-cell response in the lung of vaccinated animals characterized by (a) CXCR3+ KLRG1- lung resident T cells that are known to be essential for controlling bacterial infection, (b) IFNγ-secreting CD4+ T cells which is necessary for intracellular bactericidal activity, and (c) IL17-secreting CD4+ T cells that can confer protective immunity against multiple clinically relevant strains of Mtb. Upon challenge with aerosolized Mycobacterium tuberculosis Erdman strain, intranasal NanoSTING-H1 provides protection comparable to subcutaneous administration of the live attenuated Mycobacterium bovis vaccine strain Bacille-Calmette-Guérin (BCG). Our results indicate that NanoSTING adjuvanted protein vaccines can elicit a multi-factorial immune response that protects from infection by M. tuberculosis.

Role of folate-conjugated glycol-chitosan nanoparticles in modulating the activated macrophages to ameliorate inflammatory arthritis: in vitro and in vivo activities.

Activated macrophages are the primary targets in rheumatoid arthritis (RA) management. So, we report efficacious, dual-functional Methotrexate (MTX) loaded folate-conjugated pH-responsive glycol-chitosan nanoparticles (MFGCN) prepared by nano-precipitation and zero-order cross-linking reaction for targeting inflamed arthritic tissue. Physical characterization by DLS, SEM and TEM indicated a spherical, smooth morphology with a diameter ~ 300 nm. 1H NMR and FTIR indicated folic acid conjugation to GC by zero-order cross-linkers. In vitro release kinetics in PBS showed pH-responsive and sustained release behaviour of MFGCN. Enhanced cellular uptake and cytotoxicity of MFGCN in LPS(+)RAW and activated peritoneal macrophages (Mϕ) were observed when compared to LPS(-)RAW cells. MFGCN-induced mitochondrial membrane potential (MMP) perturbations indicated apoptosis. Oxidative stress was evident by significant increase in ROS and RNS, 4 h post incubation with MFGCN. Negligible hemolysis by FGCN and MFGCN on rat RBC's indicated biocompatibility. In vivo biodistribution of MFGCN in adjuvant-induced arthritis (AIA) rats indicated RA targetability. Prolonged blood circulation coupled with higher concentrations of 99mTc-MFGCN at the arthritic site was observed post 24 h of injection. The gamma scintigraphic image confirmed accumulation of radiolabelled MFGCN in arthritic paw when compared to the non-inflamed paw, confirming the selective uptake of 99mTc-MFGCN by folate-overexpressing macrophages in the arthritic synovium thereby proving its targeted efficacy and theranostic potential. In AIA rats, MFGCN lowers arthritic signs, improves antioxidant response and decreases pro-inflammatory cytokines, suggesting its potential in targeting activated macrophages of synovium. Graphical abstract.

Assessing the potential of lignin nanoparticles as drug carrier: Synthesis, cytotoxicity and genotoxicity studies.

Lignin nanoparticles synthesis is among recent developments in lignin valorization especially for biomedical applications. In this study, a new technique where complete self-assembling of lignin was ensured by simultaneous solvent displacement and flash pH change was used to optimize particle size of blank lignin nanoparticles (BLNPs) for suitability in cell uptake along with maximized yield. To establish BLNPs as drug carrier, safety studies including hemocompatibility, cytotoxicity and elaborate genotoxicity studies on Drosophila melanogaster as a model organism were done. Finally, irinotecan loaded lignin nanoparticles (DLNPs) were synthesized to establish their drug carrying potential and thorough in vitro characterization was performed. BLNPs with controllable size (⁓152 nm), low polydispersity (<0.2), maximized yield (>65%), negative surface charge (-22 to -23 mV), spherical shape and smooth surface were obtained with acceptable %hemolysis (<2%). In vitro cytotoxicity studies revealed that BLNPs were significantly toxic (74.38 ± 4.74%) in human breast adenocarcinoma (MCF-7), slightly toxic (38.8 ± 4.70%) in human alveolar epithelial adenocarcinoma (A-549) and insignificantly toxic (15.89 ± 2.84%) to human embryonic kidney (HEK-293) cells. BLNPs showed concentration dependent early neuronal defects in Drosophila, but nuclei fragmentation and gut cell damage were absent. Sustained release DLNPs with high drug loading reduced the IC50 value of irinotecan by almost 3 folds.

Co-Delivery of Teriflunomide and Methotrexate from Hydroxyapatite Nanoparticles for the Treatment of Rheumatoid Arthritis: In Vitro Characterization, Pharmacodynamic and Biochemical Investigations.

PURPOSE: The present investigation was aimed at developing Teriflunomide (TEF) and Methotrexate (MTX) loaded hydroxyapatite nanoparticles and increasing tolerability towards combination therapy against rheumatoid arthritis by reducing hepatotoxicity. METHODS: Drug-loaded HAp-NPs were synthesized by wet-chemical precipitation method and optimized by Box-Behnken experimental design. The developed NPs were subjected to in vitro and in vivo characterization. In-vivo pharmacodynamics and biochemical studies were performed on adjuvant- induced arthritis model treated with different formulations; MTX-TEF-SOL, TEF-HAp-NP, MTX-HAp-NP, TEF-MTX-HAp-NP, FOLITRAX-10 and AUBAGIO. RESULTS: The size of the optimized formulations, TEF-HAp-NP and MTX-HAp-NP, was found to be 224.3 ± 83.80 nm and 268.3 ± 73.86 nm with drug loading 53.11 ± 0.84% and 67.04 ± 1.12% respectively. In vitro release of TEF from TEF-HAp-NP (70.41 ± 1.22%) and MTX from MTX-HAp-NP (82.43 ± 1.31%) up to 24 h revealed sustained release pattern. Results of the arthritic assessment study showed a significant (P < 0.05) reduction in ankle diameter (61.30 ± 7.42) and arthritis score (2.35 ± 0.24) with a marked restoration of ankle joint micro-architecture in TEF-MTX-HAp-NP treated group. During Hepatotoxicity studies, liver histopathology revealed that the formulation MTX-TEF-HAp-NP was least hepatotoxic with less hepatocyte swelling and fibrous connective tissue proliferation while Folitrax-10 was found to be most hepatotoxic. Biochemical studies revealed that Folitrax-10 significantly (P < 0.05) increased the GOT (313.64 ± 16) and GPT level (334.46 ± 13) while insignificant (P > 0.05) change in GOT (263.68 ± 17) and GPT (229.38 ± 10) level was recorded with TEF-MTX-HAp-NP. CONCLUSIONS: We report that the subcutaneous delivery of TEF-MTX-HAp-NP was most effective as it successfully reduced the dosage by half for maximizing therapeutic efficacy and minimizing side effects. Graphical Abstract ᅟ.

Combined Raloxifene and Letrozole for Breast Cancer Patients.

Raloxifene, an anti-osteoporotic drug, is recently approved for prevention of breast cancer in postmenopausal women and thus the drug may be employed to combat the bony adverse effects of letrozole, another anticancer drug. However, the cytotoxic effect of their combination on human breast cancer (MCF-7) and human embryonic kidney (HEK) cell lines is not known. MCF-7 and HEK cell lines were treated with different graded doses of letrozole, raloxifene and their combination, then incubated for 24-48 h. MTT assay was performed to check the cytotoxicity of the drugs. The study indicates that the combination of letrozole and raloxifene possess additive effect in terms of cytotoxicity of cancer cell lines (MCF-7) and negligible effects in normal cell lines (HEK). Our study indicates that the addition of raloxifene doesn't interfere with anticancer efficacy of letrozole rather the combination acted additively for the treatment of breast cancer.

Preparation and evaluation of biopolymeric nanoparticles as drug delivery system in effective treatment of rheumatoid arthritis.

PURPOSE: The study purposes to evaluate nanocrystalline biopolymeric nanoparticles encapsulating methotrexate and dexamethasone with high biocompatibility, enhanced therapeutic efficacy and reduced toxicity. METHODS: Chitosan nanoparticles were prepared by ionic gelation, and Methotrexate (MTX) and Dexamethasone (DEX) were loaded during the preparation and screened for their in vitro efficacy in HEK and RAW264.7 cells, ex vivo and in vivo efficacy. RESULTS: FTIR confirmed the involvement of phosphoric group of sTPP with amine groups of chitosan and also role of hydrogen bonding involved in the preparation of MTXCHNP and DEXCHNP. Controlled release patterns coupled with diffusion of drug were observed in two different buffers (PBS) at pH 7.4 and pH 5.8. The IC50 for MTXCHNP for HEK was 26.1 µg/ml and 7.7 µg/ml for RAW 264.7 cells. In DEXCHNP, the IC50 was 20.12 µg/ml for HEK and 7.37 µg/ml for RAW264.7 cells. Enhanced uptake of FITC-CHNP by RAW cells indicated internalization of nanoparticles by phagocytosis. The enhanced release of drug at lower pH justified increased cytotoxicity. Negligible ex-vivo hemolysis indicated the higher biocompatibility of the nanoparticles. 99mTc-CHNP exhibited maximum absorption in blood circulation in 3 h, followed by hepatic metabolism and renal clearance. Higher in-vivo anti-arthritic activity and antioxidant activity was observed post-intraperitoneal (i.p.) injections by both MTXCHNP and DEXCHNP when compared to MTX (0.75 mg/Kg by i.p. route) and DEX (0.2 mg/Kg/i.p./daily) per se. CONCLUSION: The nanocrystalline biopolymeric nanoparticles were stable, biocompatible and have potential to be administered through i.p. route with minimal toxicity and high efficacy.

Vitamin C in synergism with cisplatin induces cell death in cervical cancer cells through altered redox cycling and p53 upregulation.

PURPOSE: Cervical cancer is the second most prevalent cancer in women worldwide. Survival of patients has been improved by cisplatin-based chemotherapy, but its effectiveness is limited due to its adverse effects on many tissues, especially nephrotoxicity. To optimize the efficacy of CDDP, we propose a combination therapy using natural products with minimal side effects. Vitamin C being a natural antioxidant is capable of selectively targeting cancer cells at pharmacological concentrations. Vitamin C synergistically enhances the activity of chemotherapeutic agents without increasing toxicity to normal cells. Therefore, we exploited co-therapy with cisplatin and vitamin C to kill cervical cancer cells. METHODS: We elucidated the role of CDDP and VC on cervical cancer cell line (SiHa) by using cell growth assays, DNA fragmentation analysis, comet assay, in vitro morphological assessment of apoptosis (AO/EB and DAPI staining), ROS analysis by DCFDA, flow cytometry, biochemical assays (GST, GSH, NO, catalase, TPA) and Western blotting. RESULTS: Our results clearly demonstrated that CDDP and VC treatment exhibited ameliorative effect on induction of cell death by p53 overexpression and generation of hydrogen peroxide in SiHa cells, thereby reducing the dosage of CDDP required to induce cell death in cancer cells. CONCLUSIONS: These studies provide novel approaches to combat cisplatin resistance in cervical cancer.

Synergistic anticancer efficacy of Bendamustine Hydrochloride loaded bioactive Hydroxyapatite nanoparticles: In-vitro, ex-vivo and in-vivo evaluation.

The present work evaluates the synergistic anticancer efficacy of bioactive Hydroxyapatite (HA) nanoparticles (HA NPs) loaded with Bendamustine HCl. Hydroxyapatite is a material with an excellent biological compatibility, a well-known fact which was also supported by the results of the Hemolytic studies and a high IC50 value observed in the MTT assay. HA NPs were prepared by the chemical precipitation method and loaded with the drug via physical adsorption. In-vitro release study was performed, which confirmed the sustained release of the drug from the drug loaded HA NPs. MTT assay, Cell Uptake and FACS studies on JURKAT E6.1 cell line and in-vivo pharmacokinetic studies in Wistar rats revealed that the drug loaded HA NPs could be easily internalized by the cells and release drug in a sustained manner. The drug loaded HA NPs showed cytotoxicity similar to the drug solution at 1/10th of the drug content, which indicates a possible synergism between the activity of the anticancer drug and calcium ions derived from the carrier. An increase in intracellular Ca(2+) ions is reported to induce apoptosis in cells. Tumor regression study in Balb/c mice Ehrlich's ascites model presented a similar synergistic efficacy. The drug solution was able to decrease the tumor volume by half, while the drug loaded HA NPs reduced the tumor size by 6 times.