Trained immunity of alveolar macrophages enhances injury resolution via KLF4-MERTK-mediated efferocytosis.

Recent studies suggest that training of innate immune cells such as tissue-resident macrophages by repeated noxious stimuli can heighten host defense responses. However, it remains unclear whether trained immunity of tissue-resident macrophages also enhances injury resolution to counterbalance the heightened inflammatory responses. Here, we studied lung-resident alveolar macrophages (AMs) prechallenged with either the bacterial endotoxin or with Pseudomonas aeruginosa and observed that these trained AMs showed greater resilience to pathogen-induced cell death. Transcriptomic analysis and functional assays showed greater capacity of trained AMs for efferocytosis of cellular debris and injury resolution. Single-cell high-dimensional mass cytometry analysis and lineage tracing demonstrated that training induces an expansion of a MERTKhiMarcohiCD163+F4/80low lung-resident AM subset with a proresolving phenotype. Reprogrammed AMs upregulated expression of the efferocytosis receptor MERTK mediated by the transcription factor KLF4. Adoptive transfer of these trained AMs restricted inflammatory lung injury in recipient mice exposed to lethal P. aeruginosa. Thus, our study has identified a subset of tissue-resident trained macrophages that prevent hyperinflammation and restore tissue homeostasis following repeated pathogen challenges.

Nanoparticle targeting of de novo profibrotic macrophages mitigates lung fibrosis.

The pathogenesis of lung fibrosis involves hyperactivation of innate and adaptive immune pathways that release inflammatory cytokines and growth factors such as tumor growth factor (TGF)ß1 and induce aberrant extracellular matrix protein production. During the genesis of pulmonary fibrosis, resident alveolar macrophages are replaced by a population of newly arrived monocyte-derived interstitial macrophages that subsequently transition into alveolar macrophages (Mo-AMs). These transitioning cells initiate fibrosis by releasing profibrotic cytokines and remodeling the matrix. Here, we describe a strategy for leveraging the up-regulation of the mannose receptor CD206 in interstitial macrophages and Mo-AM to treat lung fibrosis. We engineered mannosylated albumin nanoparticles, which were found to be internalized by fibrogenic CD206+ monocyte derived macrophages (Mo-Macs). Mannosylated albumin nanoparticles incorporating TGFß1 small-interfering RNA (siRNA) targeted the profibrotic subpopulation of CD206+ macrophages and prevented lung fibrosis. The findings point to the potential utility of mannosylated albumin nanoparticles in delivering TGFß-siRNA into CD206+ profibrotic macrophages as an antilung fibrosis strategy.

Albumin Nanoparticle Endocytosing Subset of Neutrophils for Precision Therapeutic Targeting of Inflammatory Tissue Injury.

The complex involvement of neutrophils in inflammatory diseases makes them intriguing but challenging targets for therapeutic intervention. Here, we tested the hypothesis that varying endocytosis capacities would delineate functionally distinct neutrophil subpopulations that could be specifically targeted for therapeutic purposes. By using uniformly sized (∼120 nm in diameter) albumin nanoparticles (ANP) to characterize mouse neutrophils in vivo, we found two subsets of neutrophils, one that readily endocytosed ANP (ANPhigh neutrophils) and another that failed to endocytose ANP (ANPlow population). These ANPhigh and ANPlow subsets existed side by side simultaneously in bone marrow, peripheral blood, spleen, and lungs, both under basal conditions and after inflammatory challenge. Human peripheral blood neutrophils showed a similar duality. ANPhigh and ANPlow neutrophils had distinct cell surface marker expression and transcriptomic profiles, both in naive mice and in mice after endotoxemic challenge. ANPhigh and ANPlow neutrophils were functionally distinct in their capacities to kill bacteria and to produce inflammatory mediators. ANPhigh neutrophils produced inordinate amounts of reactive oxygen species and inflammatory chemokines and cytokines. Targeting this subset with ANP loaded with the drug piceatannol, a spleen tyrosine kinase (Syk) inhibitor, mitigated the effects of polymicrobial sepsis by reducing tissue inflammation while fully preserving neutrophilic host-defense function.

Magnetic nanoparticles for amalgamation of magnetic hyperthermia and chemotherapy: An approach towards enhanced attenuation of tumor.

Targeted cancer therapy facilitates localizing the action of chemotherapeutic drugs at the tumor site enhancing the therapeutic efficacy and reducing the side effects to the healthy cells. The homing property of mesenchymal stem cells (MSCs), towards the tumor tissues makes them a potential cell-based delivery system for targeted cancer therapy. Along with chemotherapy, hyperthermia has gained interest as a treatment modality of cancer due to the higher sensitivity of the cancer cells towards heat and also due to its action on tumor cells to enhance sensitization towards chemotherapy or radiotherapy. In the current study, we have shown the multifaceted application of magnetic nanoparticles (MNPs) as a drug delivery vehicle to deliver anti-cancer drug paclitaxel and also as an inducer for magnetic hyperthermia under alternating magnetic field. The combined approach of paclitaxel loaded MNPs and hyperthermia demonstrated enhanced therapeutic efficacy as compared to any single therapy. Further, we have employed MSCs as carrier for these drugs loaded MNPs to achieve targeted and uniform distribution of the MNPs at the tumor site. We have evaluated the efficacy of the system in in vitro and in vivo prostate tumor model. The in vivo tumor study shows uniform distribution of drug loaded MNPs with use of mesenchymal stem cells as a delivery vehicle and combination of hyperthermia and MNP mediated drug delivery results in better tumor remission.

Cancer Nanotheranostics: A Nanomedicinal Approach for Cancer Therapy and Diagnosis.

The panorama of cancer treatment has taken a considerable leap over the last decade with the advancement in the upcoming novel therapies combined with modern diagnostics. Nanotheranostics is an emerging science that holds tremendous potential as a contrivance by integrating therapy and imaging in a single probe for cancer diagnosis and treatment thus offering the advantage like tumor-specific drug delivery and at the same time reduced side effects to normal tissues. The recent surge in nanomedicine research has also paved the way for multimodal theranostic nanoprobe towards personalized therapy through interaction with a specific biological system. This review presents an overview of the nano theranostics approach in cancer management and a series of different nanomaterials used in theranostics and the possible challenges with future directions.

Biomimetic Magnetic Nanostructures: A Theranostic Platform Targeting Lipid Metabolism and Immune Response in Lymphoma.

B-cell lymphoma cells depend upon cholesterol to maintain pro-proliferation and pro-survival signaling via the B-cell receptor. Targeted cholesterol depletion of lymphoma cells is an attractive therapeutic strategy. We report here high-density lipoprotein mimicking magnetic nanostructures (HDL-MNSs) that can bind to the high-affinity HDL receptor, scavenger receptor type B1 (SR-B1), and interfere with cholesterol flux mechanisms in SR-B1 receptor positive lymphoma cells, causing cellular cholesterol depletion. In addition, the MNS core can be utilized for its ability to generate heat under an external radio frequency field. The thermal activation of MNS can lead to both innate and adaptive antitumor immune responses by inducing the expression of heat shock proteins that lead to activation of antigen presenting cells and finally lymphocyte trafficking. In the present study, we demonstrate SR-B1 receptor mediated binding and cellular uptake of HDL-MNS and prevention of phagolysosome formation by transmission electron microscopy, fluorescence microscopy, and ICP-MS analysis. The combinational therapeutics of cholesterol depletion and thermal activation significantly improves therapeutic efficacy in SR-B1 expressing lymphoma cells. HDL-MNS reduces the T2 relaxation time under magnetic resonance imaging (MRI) more effectively compared with a commercially available contrast agent, and the specificity of HDL-MNS toward the SR-B1 receptor leads to differential contrast between SR-B1 positive and negative cells suggesting its utility in diagnostic imaging. Overall, we have demonstrated that HDL-MNSs have cell specific targeting efficiency, can modulate cholesterol efflux, can induce thermal activation mediated antitumor immune response, and possess high contrast under MRI, making it a promising theranostic platform in lymphoma.

Magnetic lipid nanocapsules (MLNCs): self-assembled lipid-based nanoconstruct for non-invasive theranostic applications.

We report magnetic nanostructure-stabilized lipid nanocapsules (MLNCs) that show superior structural stability and theranostic properties compared to conventional lipid-based nanocarriers. As therapeutic nanocarriers, the MLNCs exhibit a therapeutic efficacy that is 16 times greater than that of free drugs due to their high payload capacity and actuated drug release ability. In addition, the magnetic resonance contrast enhancement of the MLNCs is nine times higher than that of a clinically approved T2 MRI contrast agent (ferumoxytol), demonstrating the diagnostic imaging capability of the MLNCs in MRI. The self-assembly method to synthesize the lipid nanocapsules is extended to other types of nanoparticles (gold nanoparticles and quantum dots) to produce lipid nanohybrids with distinct physical properties.

Magnetic Nanoparticles Labeled Mesenchymal Stem Cells: A Pragmatic Solution toward Targeted Cancer Theranostics.

Mesenchymal stem cells (MSCs) have gained much interest to be used as targeting vehicle in cancer therapy due to the intrinsic tumor-homing behavior associated with them. In this scenario, superparamagnetic nanoparticles are emerging as an ideal probe for noninvasive cell tracking for different stem cell applications. In the study, it is demonstrated that the formulated aqueous dispersible glyceryl monooleate coated magnetic nanoparticles (MNPs) can act as a better labeling and efficient tracking agent without affecting the inherent properties of MSCs. The MNPs-MSCs facilitate the stem cell tracking by magnetic resonance imaging at a very low cell number having high T2 relaxivity and potentiates the use of MNPs-MSCs as a prospective diagnostic tool. Most importantly, the homing of MNPs-MSCs toward inflammation site, subcutaneous prostate tumor (small as well as large tumor), and in orthotopic prostate tumor suggests the clinical relevance of the system. In addition, intraperitoneal delivery of MNPs-MSCs shows enhanced tumor accumulation and less sequestration in liver as revealed by in vivo imaging and histological studies. The results here demonstrate that MNPs-MSCs may prove as a better targeted delivery agent for early diagnosis of tumors even of smaller size.

Magnetic nanoparticles: a novel platform for cancer theranostics.

Multifunctional nanoplatforms represent a cutting edge tool in biomedical applications as a result of their applicability in the concurrent monitoring of medical treatment. Magnetic nanoparticles (MNPs) have generated great interest in the field of cancer nanotheranostics owing to their intrinsic magnetic property that enables them to be used as contrast agents in magnetic resonance imaging and as a therapeutic system in conjunction with hyperthermia. In addition, the physical properties and biocompatibility of MNPs help them to act as efficient drug carriers for targeted therapeutic regimes. In this review, we have discussed the different theranostic applications of MNPs. Further, we have raised the current challenges associated with the clinical translation of MNPs along with future opportunities in this field.

The transport of non-surfactant based paclitaxel loaded magnetic nanoparticles across the blood brain barrier in a rat model.

There is much interest in utilizing the intrinsic properties of magnetic nanoparticles (MNPs) for the theranostic approaches in medicine. With an aim to develop a potential therapeutics for glioma treatment, efficacy of aqueous dispersible paclitaxel loaded MNPs (Pac-MNPs) were studied in glioblastoma cell line (U-87). The identified potential receptor, glycoprotein non-metastatic melanoma protein B (GPNMB) overexpressed by glioblastoma cells, was actively targeted using GPNMB conjugated Pac-MNPs in U-87 cells. As blood brain barrier (BBB) is the primary impediment in the treatment of glioblastoma, therefore, an attempt was taken to evaluate the biodistribution and brain uptake of Pac-MNPs in rats. The bioavailability of Pac-MNPs illustrated a prolonged blood circulation in vivo, which demonstrated the presence of significant amounts of drug in rat brain tissues as compared to native paclitaxel. Further, the transmission electron microscopy (TEM) study revealed significant accumulation of the Pac-MNPs in the brain tissues. Being an effective contrast enhancement agent for magnetic resonance imaging (MRI) at tissue levels, the MNPs devoid of any surfactant demonstrated enhanced contrast effect in liver and brain imaging. Hence, the significant prevalence of drugs in the rat brain tissues, in vitro targeting potentiality as well as the augmented contrast effect elicit the non-invasive assessment and theranostic applications of MNPs for brain tumor therapy.

Transferrin-conjugated curcumin-loaded superparamagnetic iron oxide nanoparticles induce augmented cellular uptake and apoptosis in K562 cells.

Superparamagnetic iron oxide nanoparticles are currently used for precise drug delivery and as an image contrast agent. In the present study, the potentiality of curcumin-loaded magnetic nanoparticles (Cur-MNPs) for the treatment of chronic myeloid leukemia (CML) was investigated. For active therapy, transferrin (Tf) ligand was further conjugated to Cur-MNPs, which demonstrated enhanced uptake compared to Cur-MNPs in p210bcr/abl-positive cell line (K562). Cur-MNPs demonstrated greater and sustained anti-proliferative activity in a dose- and time-dependent manner; however, with the advent of a magnetic field the anti-proliferative activity of Cur-MNPs as well as Tf-Cur-MNPs was enhanced due to higher cellular uptake with enhanced cytotoxicity activity. Down-regulation of Bcr-Abl protein activates intrinsic apoptotic pathways for promoting anti-leukemic responses. Our in vitro results advocate potential clinical applications of Cur-MNPs by activating multiple signaling pathways for provoking the anti-leukemic activity.

Long circulating lectin conjugated paclitaxel loaded magnetic nanoparticles: a new theranostic avenue for leukemia therapy.

Amongst all leukemias, Bcr-Abl positive chronic myelogenous leukemia (CML) confers resistance to native drug due to multi drug resistance and also resistance to p53 and fas ligand pathways. In the present study, we have investigated the efficacy of microtubule stabilizing paclitaxel loaded magnetic nanoparticles (pac-MNPs) to ascertain its cytotoxic effect on Bcr-Abl positive K562 cells. For active targeted therapy, pac-MNPs were functionalized with lectin glycoprotein which resulted in higher cellular uptake and lower IC(50) value suggesting the efficacy of targeted delivery of paclitaxel. Both pac-MNPs and lectin conjugated pac-MNPs have a prolonged circulation time in serum suggesting increased bioavailability and therapeutics index of paclitaxel in vivo. Further, the molecular mechanism pertaining to pac-induced cytotoxicity was analyzed by studying the involvement of different apoptotic pathway proteins by immunoblotting and quantitative PCR. Our study revealed simultaneous activation of JNK pathway leading to Bcr-Abl instability and the extrinsic apoptotic pathway after pac-MNPs treatment in two Bcr-Abl positive cell lines. In addition, the MRI data suggested the potential application of MNPs as imaging agent. Thus our in vitro and in vivo results strongly suggested the pac-MNPs as a future prospective theranostic tool for leukemia therapy.

Composite polymeric magnetic nanoparticles for co-delivery of hydrophobic and hydrophilic anticancer drugs and MRI imaging for cancer therapy.

Exercising complementary roles of polymer-coated magnetic nanoparticles for precise drug delivery and image contrast agents has attracted significant attention in biomedical applications. The objective of this study was to prepare and characterize magnetic nanoparticles embedded in polylactide-co-glycolide matrixes (PLGA-MNPs) as a dual drug delivery and imaging system capable of encapsulating both hydrophilic and hydrophobic drugs. PLGA-MNPs were capable of encapsulating both hydrophobic and hydrophilic drugs in a 2:1 ratio. Biocompatibility, cellular uptake, cytotoxicity, membrane potential, and apoptosis were carried out in two different cancer cell lines (MCF-7 and PANC-1). The molecular basis of induction of apoptosis was validated by Western blotting analysis. For targeted delivery of drugs, targeting ligand such as Herceptin was used, and such a conjugated system demonstrated enhanced cellular uptake and an augmented synergistic effect in an in vitro system when compared with native drugs. Magnetic resonance imaging was carried out both in vitro and in vivo to assess the efficacy of PLGA-MNPs as contrast agents. PLGA-MNPs showed a better contrast effect than commercial contrast agents due to higher T(2) relaxivity with a blood circulation half-life ∼ 47 min in the rat model. Thus, our results demonstrated the dual usable purpose of formulated PLGA-MNPs toward either, in therapeutics by delivering different hydrophobic or hydrophilic drugs individually or in combination and imaging for cancer therapeutics in the near future.

Dual drug loaded superparamagnetic iron oxide nanoparticles for targeted cancer therapy.

The primary inadequacy of chemotherapeutic drugs is their relative non-specificity and potential side effects to the healthy tissues. To overcome this, drug loaded multifunctional magnetic nanoparticles are conceptualized. We report here an aqueous based formulation of glycerol monooleate coated magnetic nanoparticles (GMO-MNPs) devoid of any surfactant capable of carrying high payload hydrophobic anticancer drugs. The biocompatibility was confirmed by tumor necrosis factor alpha assay, confocal microscopy. High entrapment efficiency approximately 95% and sustained release of encapsulated drugs for more than two weeks under in vitro conditions was achieved for different anticancer drugs (paclitaxel, rapamycin, alone or combination). Drug loaded GMO-MNPs did not affect the magnetization properties of the iron oxide core as confirmed by magnetization study. Additionally the MNPs were functionalized with carboxylic groups by coating with DMSA (Dimercaptosuccinic acid) for the supplementary conjugation of amines. For targeted therapy, HER2 antibody was conjugated to GMO-MNPs and showed enhanced uptake in human breast carcinoma cell line (MCF-7). The IC(50) doses revealed potential antiproliferative effect in MCF-7. Therefore, antibody conjugated GMO-MNPs could be used as potential drug carrier for the active therapeutic aspects in cancer therapy.