Bioactive ZnO-assisted 1393 glass scaffold promotes osteogenic differentiation: Some studies

We developed ZnO-assisted 1393 bioactive glass-based scaffold with suitable mechanical properties through foam replica technique and observed to be suitable for bone tissue engineering application. However, the developed scaffolds' ability to facilitate cellular infiltration and integration was further assessed through in vivo studies in suitable animal model. Herein, the pure 1393 bioactive glass (BG) and ZnO-assisted 1393 bioactive glass- (ZnBGs; 1, 2, 4 mol% ZnO substitution for SiO₂ in pure BG is named as Z1BG, Z2BG, Z3BG, respectively) based scaffolds were prepared through sol-gel route, followed by foam replica techniques and characterized by a series of in vitro and some in vivo tests. Different cell lines like normal mouse embryonic cells (NIH/3T3), mouse bone marrow stromal cells (mBMSc), peripheral blood mononuclear cells, that is, lymphocytes and monocytes (PBMC) and U2OS (carcinogenic human osteosarcoma cells) were used in determination and comparative analysis of the biological compatibility of the BG and ZnBGs. Also, the alkaline phosphatase (ALP) activity, and osteogenic gene expression by primer-specific osteopontin (OPN), osteocalcin (OCN), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were performed to study osteogenic differentiability of the stromal cells in different BGs. Moreover, radiological and histopathological tests were performed in bone defect model of Wister rats to evaluate the in vivo bone regeneration and healing. Interestingly, these studies demonstrate augmented biological compatibility, and superior osteogenic differentiation in ZnBGs, in particular Z3BG than the pure BG in most cases.

Galunisertib synergistically potentiates the doxorubicin-mediated antitumor effect and kickstarts the immune system against aggressive lymphoma

In clinical practice, major efforts are underway to identify appropriate drug combinations to boost anticancer activity while suppressing unwanted adverse effects. In this regard, we evaluated the efficacy of combination treatment with the widely used chemotherapeutic drug doxorubicin along with the TGFβRI inhibitor galunisertib (LY2157299) in aggressive B-cell non-Hodgkin lymphoma (B-NHL). The antiproliferative effects of these drugs as single agents or in combination against several B-NHL cell lines and the synergism of the drug combination were evaluated by calculating the combination index. To understand the putative molecular mechanism of drug synergism, the TGF-β and stress signaling pathways were analyzed after combination treatment. An aggressive lymphoma model was used to evaluate the anticancer activity and post-therapeutic immune response of the drug combination in vivo. Galunisertib sensitized various B-NHL cells to doxorubicin and in combination synergistically increased apoptosis. The antitumor activity of the drug combinations involved upregulation of p-P38 MAPK and inhibition of the TGF-β/Smad2/3 and PI3K/AKT signaling pathways. Combined drug treatment significantly reduced tumor growth and enhanced survival, indicating that the synergism between galunisertib and Dox observed in vitro was most likely retained in vivo. Based on the tumor-draining lymph node analysis, combination therapy results in better prognosis, including disappearance of disease-exacerbating regulatory T cells and prevention of CD8⁺ T-cell exhaustion by downregulating MDSCs. Galunisertib synergistically potentiates the doxorubicin-mediated antitumor effect without aggravating the toxic effects and the ability to kickstart the immune system, supporting the clinical relevance of targeting TGF-βRI in combination with doxorubicin against lymphoma.

Immunoinformatics based design and prediction of proteome-wide killer cell epitopes of Leishmania donovani: Potential application in vaccine development

Despite several extensive and exhaustive efforts, search for potential therapy against leishmaniasis has not made much progress. In the present work, we have employed mining strategy to screen Leishmania donovani proteome for identification of promising vaccine candidate. We have screened 21 potential antigenic proteins from 7960 total protein of L. donovani, based on the presence of signal peptide, GPI anchor, antigenicity prediction and substractive proteomic approach. Secondly, we have also performed comprehensive immunogenic epitope prediction from the screened 21 proteins, using IEDB-AR tools. Out of the 21 antigenic proteins, we obtained 11 immunogenic epitopes from 9 proteins. The final results revealed that four predicted epitopes namely; YPAFAALVF, VAVAATVAY, AAAPTEAAL and MYPLVAVVF, have significantly better binding potential with respective alleles and could elicits immune responses. Docking analysis using PATCHDOCK server and molecular dynamic simulation using GROMACS revealed the potential of the sequences as immunogenic epitopes. In silico studies also suggested that the epitopes occupied almost same binding cleft with the respective alleles, when compared with the reference peptides. It is also suggested from the molecular dynamic simulation data that the peptides were intact in the pocket for longer periods of time. Our study was designed to select MHC class I restricted epitopes for the activation of CD8 T cells using immunoinformatics for the prediction of probable vaccine candidate against L. donovani parasites. Communicated by Ramaswamy H. Sarma.

γc cytokine-aided crosstalk between dendritic cells and natural killer cells together with doxorubicin induces a healer response in experimental lymphoma by downregulating FOXP3 and programmed cell death protein 1

BACKGROUND AIMS

The stimulatory natural killer-dendritic cell axis in the tumor microenvironment could play a critical role in stimulating cytotoxic T cells and driving immune responses against cancer.

METHODS

We established a novel treatment protocol by adroitly combining chemotherapy with doxorubicin and immunotherapy with dendritic cells and natural killer cells against a highly aggressive and malignant lymphoma called Dalton's lymphoma.

RESULTS

Our data suggest that binary application of adoptive cell therapy and chemotherapy nearly cures (95%) early-stage experimental lymphoma. In the case of mid-stage cancer, the success rate was significantly lower but still impressive (75%). Our results demonstrated that the application of combination therapy in early-stage cancer significantly reduced the tumor volume and extended the lifespan of the experimental animal in addition to reinvigorating the immune system, including restoring the effector functions of dendritic cells and natural killer cells. The novel protocol limits the metastasis of tumor cells in vascularized organs and rearms the adaptive immune response mediated by dendritic cells and CD4⁺ and CD8⁺ T cells.

CONCLUSIONS

Combination therapy in the early stage alters the cytokine profile, increases interferon-γ and tumor necrosis factor-α in the serum of treated animals and downregulates programmed cell death protein 1 expression in CD8⁺ T cells. Thus, cooperative and cognitive interactions between dendritic cells and natural killer cells in addition to therapy with doxorubicin promote the immune response and tumoricidal activities against lymphoma.

Targeting thymidine phosphorylase alleviates resistance to dendritic cell immunotherapy in colorectal cancer and promotes antitumor immunity

T-cell exhaustion plays a pivotal role in the resistance of microsatellite-stable colorectal cancer (CRC) to immunotherapy. Identifying and targeting T-cell exhaustion-activating mechanisms is a promising strategy to augment the effects of immunotherapy. Here, we found that thymidine phosphorylase (TYMP) plays a decisive role in inducing systemic T-cell exhaustion and abrogating the efficacy of dendritic cell (DC) therapy in a CRC model. Targeting TYMP with tipiracil hydrochloride (TPI) induces immunological cell death (ICD). The combined effects of TPI and imiquimod-activated DCs turn CT26 tumors into immunologically ‘hot’ tumors by inducing ICD in vivo. High-dimensional cytometry analysis revealed T-cell and IFN-γ dependency on the therapeutic outcome. In addition, chemoimmunotherapy converts intratumoral Treg cells into Th1 effector cells and eliminates tumor-associated macrophages, resulting in higher cytotoxic T lymphocyte infiltration and activation. This effect is also associated with the downregulation of PD-L1 expression in tumors, leading to the prevention of T-cell exhaustion. Thus, cooperative and cognitive interactions between dendritic cells and immunogenic cell death induced by therapy with TPI promote the immune response and tumoricidal activities against microsatellite stable colorectal cancer. Our results support TYMP targeting to improve the effects of DC immunotherapy and outcomes in CRC.

Nanoscale Diamond-Based Formulation as an Immunomodulator and Potential Therapeutic for Lymphoma

Integrative medicine practices, such as Ayurveda, are popular in India and many South Asian countries, yet basic research to investigate the concepts, procedures, and medical benefits of ayurvedic products has received little attention and is not fully understood. Here, we report a functional nanodiamond-based traditional Ayurvedic herbomineral formulation, Heerak Bhasma (Ayu_ND), for the treatment of solid tumors called Dalton’s lymphoma generated in CD1 mice. Ayu_ND-mediated immunostimulation significantly reduces tumor cell proliferation and induces apoptosis aided by the active participation of dendritic cells. Immunomodulatory Ayu_ND treatment is highly immunostimulatory and drives dendritic cells to produce TNF-α. Treatment with Ayu_ND significantly reduces the tumor volume, inhibits metastasis in distant vascularized organs, and increases the life span of tumor-bearing animals compared with untreated littermates. These events were associated with elevated serum levels of the protective cytokines IFN-γ and TNF-α and downregulated the disease, exacerbating TGF-β. Ayu_ND-mediated therapeutic success was also accompanied by the depletion of regulatory T cells and enhanced vaccine-induced T-cell immunity, guided by the restoration of the memory CD8⁺ T-cell pool and prevention of PD-1-mediated T cell exhaustion. The results provide a basis for further evaluation of ayurvedic formulations and drug efficacy in treating cancers.

Antiproliferative activity and electrochemical oxygen evolution by Ni(II) complexes of N'-(aroyl)-hydrazine carbodithioates

The electrochemical water splitting by transition metal complexes is emerging very rapidly. The nickel complexes also play a very vital role in various biological activities. Here, three new ligands {H₂mbhce = N'-(4-methyl-benzoyl), H₂pchce = N'-(pyridine-carbonyl) and H₂hbhce = N'-(2-hydroxy-benzoyl) hydrazine carbodithioic acid ethyl ester} and their corresponding Ni(II) complexes [Ni(Hmbhce)₂(py)₂] (1), [Ni(pchce)(o-phen)₂]·CH₃OH·H₂O (2) and [Ni(hbhce)(o-phen)₂]·1.75CHCl₃·H₂O (3) have been synthesized and fully characterized by various physicochemical and X-ray crystallography techniques. The photoluminescence study and thermal degradations were also examined. The treatment of K562 cells with the increasing concentrations of the nickel salts, ligands, and complexes 1, 2, and 3 showed dose-dependent cytotoxicity. The cytotoxic activity of ligands reveals that ligand H₂mbhce is more potent in inhibiting the growth of tumor cells in comparison to other ligands H₂pbhce and H₂hbhce. Cytotoxicity assay results indicate that all complexes have remarkable cytotoxic potential in comparison to either nickel salts or the free ligands. Among these complexes, complex 1 has significantly better anti-tumor activity as compared to complexes 2 and 3. The electrochemical study of complexes 1, 2, and 3 for water oxidation reveals that all the complexes possess admirable electrocatalytic activity towards oxygen evolution reaction (OER) and have lower overpotential (328, 338, and 370 mV, respectively) than many previously reported complexes and RuO₂ (390 mV). Among complexes 1, 2, and 3, complex-2 shows a better water oxidation response. Consequently, these complexes have great potential to be utilized in fuel cells. The more reliable electrochemical parameter TOF is also calculated for all three complexes.

Targeting PD-1 in CD8+ T Cells with a Biomimetic Bilirubin-5-fluoro-2-deoxyuridine-Bovine Serum Albumin Nanoconstruct for Effective Chemotherapy against Experimental Lymphoma

We fabricated bilirubin-bovine serum albumin (BR-BSA) nanocomplexes as candidates for the delivery of 5-fluoro-2-deoxyuridine (5FUdr) against experimental murine lymphoma. BR was attached to 5FUdr via acid-labile ester bonds mimicking small-molecule drug conjugates. The construct was self-assembled with BSA through strong noncovalent interactions with high drug occupancy in the core and labeled with folic acid (FA) to target cancer cells. The BR-5FUdr-BSA-FA nanoconstruct exhibits excellent biocompatibility, prevents nephrotoxicity, and is tolerated by red blood cells and mononuclear cells. The construct also showed increased accumulation in lymph nodes and tumor cells. BR-5FUdr-BSA-FA caused prolonged growth inhibition and apoptosis, enhanced mitochondrial reactive oxygen species generation, and minimized the viability of parental and doxorubicin-resistant Dalton's lymphoma cells. Treatment of tumor-bearing mice with BR-5FUdr-BSA-FA significantly increased the life span of the animals, improved their histopathological parameters, and downregulated PD-1 expression, suggesting the potential of the construct for 5FUdr delivery to treat lymphoma.

Synthesis of drug conjugated magnetic nanocomposite with enhanced hypoglycemic effects

In the present study, a magnetic nanocomposite (magnetite Fe₃O₄ and hematite Fe₂O₃) has been successfully synthesized by the sol-gel method and coated with polyvinyl alcohol (PVA) followed by conjugation of anti-diabetic drug metformin. Detailed structural and microstructural characterization of the nanocomposite (NP) and drug conjugated nanocomposite (NP-DC) are analyzed by the Rietveld refinement of respective XRD patterns, FTIR analysis, UV-Vis spectroscopy, SEM and TEM results. SEM and TEM image analyses reveal the spherical morphology and average size of NP, PVA coated nanoparticles (NP-PVA) and NP-DC samples, indicating a suitable size to be a nanocarrier. The biocompatibility of NP and NP-DC was carried out in NIH/3T3 and J774A. 1 cells. The enhanced activity of the drug, when conjugated with nanocomposite, is confirmed after the treatment of both the pure drug and NP-DC sample on the 18 h fasted normoglycemic and hyperglycemic mice. The blood glucose level of the mice is effectively decreased with the same concentration of the pure drug and NP-DC sample. It proves the increased activity of the NP-DC sample, as only 5 wt% drug is present that shows the same efficiency as the pure drug. This study suggests excellent biocompatibility and cytocompatibility of NP and NP-DC besides the critical property as a hypoglycemic agent. It is the first time approach of conjugating metformin with a magnetic nanocomposite for a significant increment of its hypoglycemic activity, which is very important to reduce the side effect of metformin for its prolonged use.

A polynuclear Cu(ii) complex for real time monitoring of mitochondrial cytochrome C release during cellular apoptosis

A new amide-imine conjugate, 2-hydroxybenzoic acid-(2-hydroxybenzylidene)-hydrazide (L₁), is employed to prepare a single crystal X-ray structurally characterized poly-nuclear Cu(ii) complex (M1). M1 selectively and spatially interacts with cytochrome C (Cyt C) to allow fluorescence imaging of intracellular translocation events in living cells. Thus, direct visualization of a Cyt C translocation event during an apoptotic process is achieved for the first time. The binding constant and LOD are 7.52 × 10⁴ M^-1 and 34.0 nM, respectively.

Studies on interaction potency model based on drug synergy and therapeutic potential of triple stimuli-responsive delivery of doxorubicin and 5-fluoro-2-deoxyuridine against lymphoma using disulfide-bridged cysteine over mesoporous silica nanoparticles

A triple stimuli-responsive drug delivery platform involving doxorubicin, 5-fluoro-2-deoxy uridine and folic acid was fabricated on mesoporous silica nanoparticles for targeting delivery against a highly aggressive murine lymphoma called Dalton's lymphoma. Fabrication of the unique construct by amalgamating active and passive targeting mechanisms offers a novel hyper-chimeric platform for a stimuli-responsive drug delivery system. The novel construct enables efficient and precise delivery of the precious cargo to the tumor sites. Active targeting by folic acid directs the doxorubicin and 5-fluoro-2-deoxy uridine in the close proximities of the tumor cells, causing efficient killing and significant growth inhibition. Isobologram models, zero interaction potency dose-response surface plots and matrices were generated to evaluate the combination synergism of the two drugs. Therapy with the dual drug-bearing construct in mice with established tumors significantly reduced the tumor load and enhanced the survival of the animals compared with the untreated control. Therapy with the dual delivery system also augmented the innate and adaptive immune defense mechanisms of the treated animals. CD8⁺ T cells, natural killer cells and the dendritic cells from the treated group following successful therapy with the novel construct showed enhanced cytotoxicity and growth inhibitory capacities against DL tumor cells.

Essential role of TNF-α in gamma c cytokine aided crosstalk between dendritic cells and natural killer cells in experimental murine lymphoma

Cooperative and cognitive interaction between the dendritic cells and natural killer cells was investigated for demonstrating the anti-tumor activity against an aggressive murine lymphoma, treated with doxorubicin. Crosstalk between the dendritic cells and the natural killer cells significantly reduced the proliferation of Dalton's lymphoma cells in a dose dependent manner. Treatment of Dalton's lymphoma cells with doxorubicin in vitro enhances the effects of crosstalk against the target cells. This crosstalk between the cells was regulated via stimulation with recombinant interleukin-15, and release of TNF-α which is critically important for the tumoricidal effects. Dendritic cells and the natural killer cells crosstalk activate both the cells and upregulate the expression of CD40, CD69 and CD86 on the dendritic cells. These findings provided new insight regarding these interactions and define a mechanism by which cellular immune response promotes tumoricidal activity against lymphoma in therapeutic setting.

Doxorubicin loaded pH responsive biodegradable ABA-type Amphiphilic PEG-b-aliphatic Polyketal-b-PEG block copolymer for therapy against aggressive murine lymphoma

A novel ABA-type polyethylene glycol (PEG)-b-polyketal (PK)-b-PEG block copolymer was synthesized via click reactions between the monoazido-monomethoxy-PEG and dialkyne terminated aliphatic polyketal with no carboxylic/amide linkages. Formation of the novel block copolymer was confirmed by ¹H NMR, GPC, TGA, and DSC studies. The formed copolymer has shown faster degradation at acidic pH. Self-assembly of this block copolymer (average size 6.2 nm) was assessed by fluorescence study using pyrene as a probe. Doxorubicin loaded block copolymeric micelles (69.9 nm) have shown pH dependent elevated drug release at pH 6.4, indicating its potential as a pH responsive nano-carrier for anticancer therapy. The nano-sized copolymer demonstrated tumoricidal activities against the lymphoma of murine and human origin with significant levels of growth inhibition and apoptosis. Therapy with doxorubicin loaded copolymer reduced the tumor size and augmented the life span of the tumor bearing animals with improved histopathological parameters, compared with the untreated control.

Oxovanadium(V) and Dioxomolybdenum(VI) Complexes of Amide-Imine Conjugates: Structures, Catalytic and Antitumor Activities

Three new amide-imine conjugates, namely [(E)-2-hydroxy-N'-((2-hydroxynaphthalen-1-yl)methylene)benzohydrazide] (SALNP), [(E)-N'-(4-(diethylamino)-2-hydroxybenzylidene)-2-hydroxybenzohydrazide] (SALSD), and [(E)-N'-(3-ethoxy-4-hydroxybenzylidene)-2-hydroxybenzohydrazide] (SALVN), derived by reacting 2-hydroxybenzohydrazide (SAL) with three different aldehyde, 2-hydroxynapthaldehyde, 4-(diethylamino)-2-hydroxybenzaldehyde, and 3-ethoxy-4-hydroxybenzaldehyde, respectively. Three mononuclear oxovanadium(V) and two μ_oxo-bridged dinuclear molybdenum(VI) complexes have been synthesized using SALNP and SALSD. Besides, SALVN is used to prepare oxovanadium(V) and dioxomolybdenum(VI) complexes. All five metal complexes along with three amide-imine conjugates are characterized by single crystal XRD analysis. Some of them have been explored as catalyst for oxidation of alkyl benzene and styrene. Antitumor activities of the metal complexes along with ligands have been studied on Dalton lymphoma (DL) and 2PK3 murine lymphoma cells.

Azouracil and Its Cu(II)-Catalyzed Cyclization to an Anticancer Active Triazole Derivative: Symmetrical and Asymmetrical Reductive Cleavage, DNA Interaction, and Molecular Docking Studies

The 6-amino-1,3-dimethyl uracil-based azo derivative (p-carboxy phenylazouracil, L11) undergoes Cu(II)-catalyzed cyclization to a triazole derivative, namely, 1,3-dimethyl-8-(p-carboxy phenyl) azapurine (L11P). Interestingly, the azo functionality of L11 undergoes both symmetrical and asymmetrical reductive cleavage at two different reaction conditions. The chloride salts of Mn(II), Ni(II), and Pd(II) catalyze reductive cleavage of an azo moiety in an asymmetric manner, producing a new uracil hydrazine derivative (A3). On the other hand, hydrazine catalyzes symmetrical reductive cleavage of the azo moiety of L11, resulting in 5,6-diamino-1,3-dimethyl uracil (A2) along with the starting p-aminobenzoic acid (A1). Time-dependent density functional theoretical (TD-DFT) studies provide optimized geometries of L11, L11P, and A3 along with their orbital energies. The L11 and L11P bind firmly to genomic DNA of E. coli with a site size n ∼ 9 and n ∼ 8. The L11P shows anticancer activity on selected murine lymphoma cancer cell lines (DL, YAC1, and 2PK3). In addition, its antiproliferative activity is measured with several cancer cell lines and found hemocompatible toward blood cells. Corresponding molecular docking studies of L11P with caspase-3 (cysteine-aspartic proteases) unlock their mode of interaction.

A unique benzimidazole-naphthalene hybrid molecule for independent detection of Zn2+ and N3- ions: Experimental and theoretical investigations

Single crystal X-ray structurally characterized benzimidazole-naphthalene hybrid (NABI) functions as a unique dual analyte sensor that can detect Zn²⁺ cation and N₃^- anion independently. The NABI forms chelate with Zn²⁺ to inhibit internal charge transfer (ICT) and CHN isomerisation resulting chelation enhanced fluorescence (CHEF). On the other hand, the sensing of N₃^- is based on formation of supramolecular H-bonded rigid assembly. The association constant of NABI for Zn²⁺ and N₃^- ions are 19 × 10⁴ M^-1 and 11 × 10² M^-1, respectively. Corresponding limit of detections (LOD) are 6.85 × 10^-8 and 1.82 × 10^-7 M, respectively. NABI efficiently detects intracellular Zn²⁺ and N₃^- ions with no cytotoxicity on J774A.1cells under fluorescence microscope. DFT studies unlock underlying spectroscopic properties of free NABI and Zn²⁺/N₃^- bound forms.

ATP-Decorated Mesoporous Silica for Biomineralization of Calcium Carbonate and P2 Purinergic Receptor-Mediated Antitumor Activity against Aggressive Lymphoma

Adenosine triphosphate (ATP) is an important transmitter that mediates various biological effects via purinergic receptors (P2 receptors) in cancer. We investigated the antitumor activity of ATP-decorated and doxorubicin (DOX)-loaded mesoporous silica with biomineralization of calcium carbonate against a highly aggressive and metastatic murine lymphoma called Dalton's lymphoma (DL). Our results suggest that this nanocomposite has unique effects with respect to the morphology and properties of calcium carbonate on the surface of the nanoparticle. DOX in the nanoparticles was prevented from quick release via the interactions of the phosphate group present on ATP and calcium carbonate. This construct is significantly tumoricidal against parental and DOX-resistant DL cells and is thus a promising candidate for applications in drug delivery. The composite nanomaterial has excellent biocompatibility with higher uptake and acts via the participation of the purinergic receptor P2X7. The nanocomposite induces significantly higher apoptosis in tumor cells compared with DOX alone. Treatment of DL-bearing mice with the construct significantly reduces tumor burden, in addition to augmenting the lifespan of tumor-bearing mice as demonstrated by a sustained healthy life of the animals and improved histopathological parameters.

Water switched aggregation/disaggregation strategies of a coumarin–naphthalene conjugated sensor and its selectivity towards Cu2+ and Ag+ ions along with cell imaging studies on human osteosarcoma cells (U-2 OS)

A simple coumarin–naphthalene conjugated chemosensor (R1) exhibited an excellent AIE effect in methanol/water (1 : 1).

Evaluation of carbofuran-mediated toxicity against human lymphocytes and red blood cells in simulated wastewater degraded by coagulation-flocculation

Coagulation-flocculation in water treatment has been relied upon aluminum (Al) and iron (Fe) salts for treatment of contaminants present in source waters containing dissolved organic compounds. However, water quality deteriorates day by day which makes it urgent to improve the standards of the treatment procedure. Coagulation-flocculation-sedimentation performance of ferric chloride and alum was comparatively investigated for carbofuran treatment in simulated wastewater. Coagulation trails were performed in a jar test at several pH levels and coagulant doses to determine reduction efficiencies of carbofuran degradation and chemical oxygen demand (COD). Effect of carbofuran on proliferation, viability, and direct cytotoxicity was performed using human neuroblastoma cells U-87. Direct toxicity of carbofuran on human mononuclear cells and red blood cells (RBC) was also analyzed. Carbofuran and its derivatives were found to be relatively safe at low concentration (2-5 μM). However, at slightly higher concentration (8 μM), a moderate loss in viability and proliferative potential was observed. Taken together, these results suggest that carbofuran appears to be safe at moderate or low concentration with respect to viability of normal human lymphocytes and RBC.

Brightening Quinolineimines by Al3+ and Subsequent Quenching by PPi/PA in Aqueous Medium: Synthesis, Crystal Structures, Binding Behavior, Theoretical and Cell Imaging Studies

Recent years have witnessed an upsurge of Al³⁺ selective optical sensors involving simple Schiff bases to other complex organic frameworks. However, more than ∼95% of such reports lack crystallographic evidence, and proposals of binding sites for Al³⁺ are based upon spectroscopic evidence only. We herein synthesized and fully characterized a quinolineimine derivative (CMO) and explored its potential toward efficient detection of Al³⁺ with crystallographic evidence. The ongoing nonradiative photoinduced electron transfer (PET) and excited state intramolecular proton transfer (ESIPT) processes in CMO got inhibited via the chelation enhanced fluorescence (CHEF) effects induced by Al³⁺, and consequently turn-on fluorescence response was observed with 18-fold emission enhancements. The theoretical calculations performed were in good consonance with experimental results. We also explored further the applicability of the CMO·Al³⁺ complex toward highly sensitive and selective detection of inorganic phosphate (PPi) and an explosive picric acid (PA) via fluorescence quenching processes through two different chemical routes. The bioimaging of Al³⁺ and PPi were carried out in the living human cancer cells (MCF-7).

Enhanced bioactivity, biocompatibility and mechanical behavior of strontium substituted bioactive glasses

Strontium contained biomaterials have been reported as a potential bioactive material for bone regeneration, as it reduces bone resorption and stimulates bone formation. In the present investigation, the bioactive glasses were designed to partially substitute SrO for SiO2 in Na2O-CaO-SrO-P2O5-SiO2 system. This work demonstrates that the substitution of SrO for SiO2 has got significant benefit than substitution for CaO in the bioactive glass. Bioactivity was assessed by the immersion of the samples in simulated body fluid for different intervals. The formation of hydroxy carbonate apatite layer was identified by X-ray diffractometry, scanning electron microscopy (SEM) and energy dispersive spectroscopy. The elastic modulus of the bioactive glasses was measured and found to increase with increasing SrO for SiO2. The blood compatibility of the samples was evaluated. In vitro cell culture studies of the samples were performed using human osteosarcoma U2-OS cell lines and found a significant improvement in cell viability and proliferation. The investigation showed enhancement in bioactivity, mechanical and biological properties of the strontia substituted for silica in glasses. Thus, these bioactive glasses would be highly potential for bone regeneration.

Methotrexate-Loaded Four-Arm Star Amphiphilic Block Copolymer Elicits CD8+ T Cell Response against a Highly Aggressive and Metastatic Experimental Lymphoma

We have synthesized a well-defined four-arm star amphiphilic block copolymer [poly(DLLA)-b-poly(NVP)]4 [star-(PDLLA-b-PNVP)4] that consists of D,L-lactide (DLLA) and N-vinylpyrrolidone (NVP) via the combination of ring-opening polymerization (ROP) and xanthate-mediated reversible addition-fragmentation chain transfer (RAFT) polymerization. Synthesis of the polymer was verified by 1H NMR spectroscopy and gel permeation chromatography (GPC). The amphiphilic four-arm star block copolymer forms spherical micelles in water as demonstrated by transmission electron microscopy (TEM) and 1H NMR spectroscopy. Pyrene acts as a probe to ascertain the critical micellar concentration (cmc) by using fluorescence spectroscopy. Methotrexate (MTX)-loaded polymeric micelles of star-(PDLLA15-b-PNVP10)4 amphiphilic block copolymer were prepared and characterized by fluorescence and TEM studies. Star-(PDLLA15-b-PNVP10)4 copolymer was found to be significantly effective with respect to inhibition of proliferation and lysis of human and murine lymphoma cells. The amphiphilic block copolymer causes cell death in parental and MTX-resistant Dalton lymphoma (DL) and Raji cells. The formulation does not cause hemolysis in red blood cells and is tolerant to lymphocytes compared to free MTX. Therapy with MTX-loaded star-(PDLLA15-b-PNVP10)4 amphiphilic block copolymer micelles prolongs the life span of animals with neoplasia by reducing the tumor load, preventing metastasis and augmenting CD8+ T cell-mediated adaptive immune responses.

Downregulation of STAT3 phosphorylation enhances tumoricidal effect of IL-15-activated dendritic cell against doxorubicin-resistant lymphoma and leukemia via TNF-α

Although disputed by some, increasing evidence suggests that TNF-α synergies with traditional chemotherapeutic drugs to exert a heightened antitumor effect. The present study investigated the antitumor efficacy of recombinant IL-15 in combination with the STAT3 inhibitor cucurbitacin-I in a doxorubicin-resistant murine lymphoma model. The significance of the work is to understand and design effective strategies in doxorubicin resistant lymphomas. TNF-α is downregulated in dendritic cells from mice with Dalton's lymphoma and shows an inverse relationship with disease progression. Doxorubicin-resistant DL cells have elevated levels of Bcl-2 and Mcl-1 and increased phosphorylation of STAT3. These cells are refractory to dendritic cell derived TNF-α. Doxorubicin resistant Dalton's lymphoma is susceptible to dendritic cell derived TNF-α upon stimulation with the STAT3 inhibitor cucurbitacin-I, which downregulates STAT3 and other survival molecules. The combined treatment of low dose of cucurbitacin-I and rIL-15 is ineffective in mice with doxorubicin resistant Dalton's lymphoma, but a similar therapy prolongs the survival of mice transplanted with parental Dalton's lymphoma. Doxorubicin resistant Dalton's lymphoma responds to therapy with high doses of cucurbitacin-I and rIL-15. Dendritic cell derived from mice responded positively to the therapy and regained their tumoricidal properties with respect to growth inhibition and killing of DL tumor cells. Similar to DL, DC derived from CML patients are impaired in TNF-α expression and are unable to restrict the growth of drug-resistant lymphoma and leukemia cells. This combination approach could be used as a new therapeutic strategy for aggressive and highly metastatic doxorubicin resistant lymphoma.

Tadpole-shaped β-cyclodextrin-tagged poly(N-vinylpyrrolidone): synthesis, characterization and studies of its complexation with phenolphthalein and anti tumor activities

DOX-loaded β-CD-PNVP shows more effective delivery of DOX compared to free DOX towards the U2-OS, MCF-7 and HEPG2 cell lines.

Cellular therapy by allogeneic macrophages against visceral leishmaniasis: role of TNF-α

Tumor necrosis factor α (TNF-α) is an essential player in infection with Leishmania, controlling inflammatory lesion and parasite killing. We recently have shown the leishmanicidal activity of transmembrane form of TNF (mTNF) derived from allogeneic natural killer (NK) cells in experimental visceral leishmaniasis. Allogeneic macrophages and human monocytes derived mTNF has significantly higher antileishmanial activity compared to allogeneic NK cells. Unlike NK cells, syngeneic macrophages also possess antileishmanial activity, although degree of activity is significantly less compared to allogeneic macrophages. Cellular therapy by intravenous transfer of allogeneic macrophages enhances leishmanicidal effect against the established infection in susceptible animal by reducing the splenic parasite burden to 28.3 ± 4.71 × 10(5) compared to 256.00 ± 17.36 × 10(5) in control group. In vivo treatment with anti-mouse TNF-α reduces the therapeutic efficacy of the allogeneic macrophages by increasing the parasite load in spleen of infected mice. These results demonstrated that allogeneic and xenogeneic macrophages induce cytokine mediated protective mechanism against infected macrophages via TNF-α in vitro and, possibly in vivo. The macrophage mediated protective role in absence of T cell help demonstrate an unique property of the mononuclear phagocytes in controlling infection and inflammation in visceral leishmaniasis, despite being acts as a host cell for the same parasite.

Targeted delivery of doxorubicin-loaded poly (ε-caprolactone)-b-poly (N-vinylpyrrolidone) micelles enhances antitumor effect in lymphoma

Background

The present study was motivated by the need to design a safe nano-carrier for the delivery of doxorubicin which could be tolerant to normal cells. PCL₆₃-b-PNVP₉₀ was loaded with doxorubicin (6 mg/ml), and with 49.8% drug loading efficiency; it offers a unique platform providing selective immune responses against lymphoma.

Methods

In this study, we have used micelles of amphiphilic PCL₆₃-b-PNVP₉₀ block copolymer as nano-carrier for controlled release of doxorubicin (DOX). DOX is physically entrapped and stabilized in the hydrophobic cores of the micelles and biological roles of these micelles were evaluated in lymphoma.

Results

DOX loaded PCL₆₃-b-PNVP₉₀ block copolymer micelles (DOX-PCL₆₃-b-PNVP₉₀) shows enhanced growth inhibition and cytotoxicity against human (K-562, JE6.1 and Raji) and mice lymphoma cells (Dalton's lymphoma, DL). DOX-PCL₆₃-b-PNVP₉₀ demonstrates higher levels of tumoricidal effect against DOX-resistant tumor cells compared to free DOX. DOX-PCL₆₃-b-PNVP₉₀ demonstrated effective drug loading and a pH-responsive drug release character besides exhibiting sustained drug release performance in in-vitro and intracellular drug release experiments.

Conclusion

Unlike free DOX, DOX-PCL₆₃-b-PNVP₉₀ does not show cytotoxicity against normal cells. DOX-PCL₆₃-b-PNVP₉₀ prolonged the survival of tumor (DL) bearing mice by enhancing the apoptosis of the tumor cells in targeted organs like liver and spleen.

IL-15 activated human peripheral blood dendritic cell kill allogeneic and xenogeneic endothelial cells via apoptosis

IL-15 is a pleotropic cytokine, which plays an important role in natural killer (NK) cell activity, T cell proliferation, and T cell cytotoxic activity. Dendritic cells (DCs) are the major antigen presenting cells in the immune system and presumed to play an important role in immune recognition of allo and xenotransplantation. We showed that IL-15 activated human peripheral blood DC is cytotoxic to human and porcine aortic endothelial cells. Unlike DCs, CD14+ monocytes show no cytotoxicity against the endothelial cells. This cytotoxic potential of IL-15 activated DC against endothelial cells is dose dependent and increases significantly upon treatment of endothelial cells with inflammatory cytokines like TNF-α or IFN-γ. The cytotoxic potential of IL-15 activated DC is associated with apoptosis of endothelial cells, as indicated by the increased Annexin V staining, caspase activation and loss of mitochondrial membrane potential. Further it was observed that DC mediated cytotoxicity against endothelial cell is mediated via granzyme B possibly secreted by the activated DCs.

Down regulation of CD24 and HER-2/neu in breast carcinoma cells by activated human dendritic cell. Role of STAT3

Human dendritic cells (DCs) stimulated with cytokines and LPS down regulate the expression of proto-oncogene HER-2/neu and GPI linked protein CD24 in breast cancer cell lines. We demonstrated that naïve DC from human peripheral blood, when stimulated with IFN-γ, IL-15 or LPS reduces the expression of HER-2/neu and CD24, via activation of TNF-α. Pretreatment of tumor cells with STAT3 specific inhibitors or knocking down of STAT3 by SiRNA makes the tumor cell more susceptible to apoptosis and DC mediated inhibition of both CD24 and HER-2/neu. Thus DC could acts as an inhibitory regulator in suppressing oncogene and prevention of metastasis.

Hepatic pathology in AIDS: a pathological study from Mumbai, India

OBJECTIVES

To assess the spectrum of hepatic disorders in AIDS, liver specimens from 171 patients (155 autopsies and 16 biopsies) were reviewed.

METHODS

A retrospective and prospective study of 171 autopsy and biopsy specimens was carried out at a tertiary level hospital in Mumbai, India.

RESULTS

Of the patients included in the study, 127 (74%) were male and 44 (26%) were female. The heterosexual route was the predominant mode of HIV transmission, identified in 163 (95%) patients. A total of 99 of 171 patients (58%) showed significant pathological lesions, and the most common pathological processes involving the liver appeared to be secondary to infections. None of our patients showed isolated infectious diseases of the liver. The spectrum of liver diseases identified was as follows: tuberculosis in 70 patients (41%), cryptococcosis in eight (5%), cytomegalovirus infection in six (3%), hepatitis B infection in five (3%), candidiasis in one (0.5%), malaria in one (0.5%), cirrhosis in six (3%), amyloidosis in one (0.5%) and primary hepatic lymphoma in one (0.5%).

CONCLUSIONS

AIDS patients were found to have a high prevalence of underlying hepatic abnormalities. The spectrum of disease among patients with AIDS in India differs from that in developed countries. Our results suggest that hepatic tuberculosis is more common in AIDS than previously recognized, and that liver specimens should be examined routinely for the presence of acid-fast bacilli.

Evidence of AIDS-related mortality in Mumbai, India

From an estimated 85,200 HIV-infected individuals in Mumbai in 1997, at least 4120 excess deaths attributed to AIDS occurred among 15-54-year-olds. To prevent repetition of this excess in other parts of India, priority intervention programmes should be instituted quickly because the window of opportunity is closing quickly.

Severe weight loss: the predominant clinical presentation of tuberculosis in patients with HIV infection in India

BACKGROUND

Tuberculosis is endemic in India and its prevalence is reported to be increasing in patients with human immuno-deficiency virus (HIV) infection. Several factors, including the level of immune deficiency, influence the clinical presentation of HIV-associated tuberculosis.

METHODS

Between April 1994 and April 1996, 1820 patients with confirmed HIV infection were studied for their clinical, radiological and laboratory parameters. Severe weight loss was observed as a frequent presenting complaint. Hence, a case-control analysis was performed using severe weight loss as the presenting criterion among HIV-seropositive patients.

RESULTS

Of the 1820 patients with HIV infection, 410 (23%) presented with severe weight loss of > 10% of body weight within the preceding month. Of these 410 patients, 176 (43%) had tuberculosis, 94 (23%) had chronic diarrhoea, and 89 (22%) had recurrent fever. Among 176 patients with tuberculosis, the following types of HIV-associated tuberculosis were seen: 115/176 (66%) had pulmonary, 49/176 (28%) had extrapulmonary tuberculosis; of these 49 cases with extrapulmonary tuberculosis 33 (18%) had disseminated tuberculosis, and 12/176 (7%) had both pulmonary and extrapulmonary involvement. In the group as a whole, 45/176 (25%) cases had disseminated tuberculosis. Clinical features of HIV-associated tuberculosis in decreasing order of frequency were chronic fever, chronic cough, lymphadenopathy and hepatosplenomegaly. The Mantoux skin test was significantly anergic among patients with extrapulmonary and disseminated tuberculosis (p = 0.001).

CONCLUSIONS

There was a significant correlation between severe weight loss and tuberculosis (RR 17.5), chronic diarrhoea (RR 12.8) and recurrent fever (RR 4.5). The diagnostic value of the Mantoux skin test among HIV-associated tuberculosis is reduced, more so among those with extrapulmonary and disseminated forms.