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.

Telomerase Responsive Delivery of Doxorubicin from Mesoporous Silica Nanoparticles in Multiple Malignancies: Therapeutic Efficacies against Experimental Aggressive Murine Lymphoma.

Mammalian telomerase maintains the length and integrity of telomeres by adding the telomeric repeats to the chromosome end. This work describes the telomerase responsive delivery of doxorubicin against telomerase positive human and murine cancer cells. Wrapping of doxorubicin loaded mesoporous silica nanoparticles with specific oligonucleotide sequence, containing telomeric repeat complementary sequence and a telomerase substrate primer sequence, resulted in slow and sustained release of doxorubicin, contiguous to the tumor cells. The DNA wrapped nanoprobe significantly inhibits the proliferation and enhanced the cytotoxicity in telomerase positive human and mouse tumor cells, and its function is impeded following exposure to specific telomerase inhibitor, AZT. Entrapping of doxorubicin by telomerase specific oligo manifests enhanced apoptosis and significantly higher uptake of the drug in the tumor cells. Treatment of telomerase positive Dalton's lymphoma bearing mice with a novel and newly designed oligo wrapped nanoprobe, specific for mouse telomerase, significantly enhanced the survival and improved the histopathological parameters. In addition, the treatment also induced significant reduction in the number of tumor foci and restored the normal architecture of the vascularized organs, besides preventing metastasis.

Aggregation-induced enhanced green light emission from a simple donor-π-acceptor (D-π-A) material: a structure-property relationship study.

Organic D-π-A materials, possessing intramolecular charge transfer, have attracted much scientific attention in recent years because of their potential applications in the development of organic light emitting devices (OLEDs). Two new compounds, A1 and A2, having a D-π-A skeleton have been synthesized and single crystals were grown by the solution growth technique. Both compounds were characterized for crystallographic, thermal and photophysical properties. Upon photo-excitation in the solid state, A1 showed very strong green light emission while A2 gave sky-blue emission with much lower intensity. A single crystal X-ray diffraction study revealed that in the crystal lattice of A1, both the donor and acceptor groups are involved in the intermolecular interactions. This results in the restricted intramolecular rotation (RIR) of the D and A moieties, and enables A1 to emit more intensely in the solid state due to aggregation-induced emission (AIE). Intense green light emission, along with a good crystalline nature indicates that A1 might be a potential candidate for opto-electronic devices.

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.

Donor-π-Acceptor-Type Configured, Dimethylamino-Based Organic Push-Pull Chromophores for Effective Reduction of Mild Steel Corrosion Loss in 1 M HCl.

In this work, donor-π-acceptor-type four crystalline compounds have been tested for the first time to restrict the corrosion of mild steel in 1 M HCl. The details of the compounds are: C1, 4-N,N-dimethylamino-ß-nitrostyrene; C2, 2-(4-(dimethylamino) benzylidene)malononitrile; C3, ethyl 2-cyano-3-(4-(dimethylamino) phenyl)acrylate; and C4, methyl 2-cyano-3-(4-(dimethylamino)phenyl)acrylate. The corrosion inhibition potentials of the compounds have been primarily investigated by electrochemical techniques, such as linear polarization resistance, Tafel polarization curves, and electrochemical impedance spectroscopy. The secondary investigation is performed by scanning electron microscopy, fluorescence surface imaging, spectroscopic techniques (UV-visible and Fourier transform infrared spectroscopy), and X-ray diffraction patterns. The results disclosed that 50 mg L-1 of the compounds (1-4) in 1 M HCl provided the maximum inhibition efficiency as 93% (1), 88% (2), 82% (3), and 86% (4). The function of the compounds as corrosion inhibitors is explained with equilibrium corrosion potential, adsorption isotherms, and the frontier molecular orbital energies of the compounds (E HOMO and E LUMO) estimated by cyclic voltammetry curves and UV-visible spectra.

Pepsin Assisted Doxorubicin Delivery from Mesoporous Silica Nanoparticles Downsizes Solid Tumor Volume and Enhances Therapeutic Efficacy in Experimental Murine Lymphoma.

Pepsin, a digestive enzyme, plays an important role in the metabolism of protein products in the stomach. The pH is regarded as the most pivotal criteria in appraising the pepsin's enzymatic activity. Pepsin is idle at the physiological pH (7.4) but dynamic in the acidic environments of the stomach (pH 2.0-4.0). Inspired by such pH regulatory actions, we have used pepsin as an enhancer, which is attached to silica nanoparticles for the doxorubicin release in the acidic tumor environment. Pepsin enzyme is transitional between the doxorubicin loaded silica nanoparticles and the biotin-avidin cap system, which intercedes the pores. The formed nanoplatform is poised at the physiological pH. However, when switched to low pH simulated conditions, the pepsin become vibrant and cleaves the avidin, rendering the clearance of the path for the diffusion of the drug. This design strategy augmented the drug bioavailability deep inside the solid tumor with enhanced uptake and apoptosis of the tumor cells in experimental lymphoma.

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.

Protease-Responsive Targeted Delivery of Doxorubicin from Bilirubin-BSA-Capped Mesoporous Silica Nanoparticles against Colon Cancer.

Bilirubin is regarded as a toxic waste, produced from heme degradation and also acts as a potentially important antioxidant. Bilirubin causes arrest in cell cycle and lead to lesser occurrence of malignancies in individuals, having normal or slender increase in levels of serum bilirubin. Prompted by the dynamic interaction between bilirubin and bovine serum albumin (BSA), bilirubin-BSA complex was explored as a biocompatible cap system for protease responsive delivery device of anticancer drug against colon cancer. Bilirubin, conjugated to the amine terminated and doxorubicin loaded mesoporous silica nanoparticles were employed as a novel formulation against colon carcinoma cells. Compared to doxorubicin only, bilirubin in combination with doxorubicin-loaded mesoporous silica nanoparticle significantly inhibits tumor cell growth as assessed in MC-38 (murine) and HCT-116 (human) colon cancer cells. Bilirubin-doxorubicin combination potently inhibits proliferation of tumor cells and acted as cytotoxic and pro-apoptotic agent in vitro. Our result demonstrates that this novel cap system could play a precise role in defense against colon cancer by interrupting the pro-cancerogenic survival pathways during carcinogenesis.