Biodistribution of negatively charged iron oxide nanoparticles (IONPs) in mice and enhanced brain delivery using lysophosphatidic acid (LPA)

Near infrared-emitting multimodal nanosystem for in vitro magnetic hyperthermia of hepatocellular carcinoma and dual imaging of in vivo liver fibrosis

Prolonged usage of traditional nanomaterials in the biological field has posed several short- and long-term toxicity issues. Over the past few years, smart nanomaterials (SNs) with controlled physical, chemical, and biological features have been synthesized in an effort to allay these challenges. The current study seeks to develop theranostic SNs based on iron oxide to enable simultaneous magnetic hyperthermia and magnetic resonance imaging (MRI), for chronic liver damage like liver fibrosis which is a major risk factor for hepatocellular carcinoma. To accomplish this, superparamagnetic iron oxide nanoparticles (SPIONs) were prepared, coated with a biocompatible and naturally occurring polysaccharide, alginate. The resultant material, ASPIONs were evaluated in terms of physicochemical, magnetic and biological properties. A hydrodynamic diameter of 40 nm and a transverse proton relaxation rate of 117.84 mM-1 s-1 pronounces the use of ASPIONs as an efficient MRI contrast agent. In the presence of alternating current of 300 A, ASPIONs could elevate the temperature to 45 °C or more, with the possibility of hyperthermia based therapeutic approach. Magnetic therapeutic and imaging potential of ASPIONs were further evaluated respectively in vitro and in vivo in HepG2 carcinoma cells and animal models of liver fibrosis, respectively. Finally, to introduce dual imaging capability along with magnetic properties, ASPIONs were conjugated with near infrared (NIR) dye Atto 700 and evaluated its optical imaging efficiency in animal model of liver fibrosis. Histological analysis further confirmed the liver targeting efficacy of the developed SNs for Magnetic theranostics and optical imaging as well as proved its short-term safety, in vivo.

In vivo Biodistribution and Clearance of Magnetic Iron Oxide Nanoparticles for Medical Applications

Magnetic iron oxide nanoparticles (magnetite and maghemite) are intensively studied due to their broad potential applications in medical and biological sciences. Their unique properties, such as nanometric size, large specific surface area, and superparamagnetism, allow them to be used in targeted drug delivery and internal radiotherapy by targeting an external magnetic field. In addition, they are successfully used in magnetic resonance imaging (MRI), hyperthermia, and radiolabelling. The appropriate design of nanoparticles allows them to be delivered to the desired tissues and organs. The desired biodistribution of nanoparticles, eg, cancerous tumors, is increased using an external magnetic field. Thus, knowledge of the biodistribution of these nanoparticles is essential for medical applications. It allows for determining whether nanoparticles are captured by the desired organs or accumulated in other tissues, which may lead to potential toxicity. This review article presents the main organs where nanoparticles accumulate. The sites of their first uptake are usually the liver, spleen, and lymph nodes, but with the appropriate design of nanoparticles, they can also be accumulated in organs such as the lungs, heart, or brain. In addition, the review describes the factors affecting the biodistribution of nanoparticles, including their size, shape, surface charge, coating molecules, and route of administration. Modern techniques for determining nanoparticle accumulation sites and concentration in isolated tissues or the body in vivo are also presented.

Nanoparticle biodistribution coefficients: A quantitative approach for understanding the tissue distribution of nanoparticles

The objective of this manuscript is to provide quantitative insights into the tissue distribution of nanoparticles. Published pharmacokinetics of nanoparticles in plasma, tumor and 13 different tissues of mice were collected from literature. A total of 2018 datasets were analyzed and biodistribution of graphene oxide, lipid, polymeric, silica, iron oxide and gold nanoparticles in different tissues was quantitatively characterized using Nanoparticle Biodistribution Coefficients (NBC). It was observed that typically after intravenous administration most of the nanoparticles are accumulated in the liver (NBC = 17.56 %ID/g) and spleen (NBC = 12.1 %ID/g), while other tissues received less than 5 %ID/g. NBC values for kidney, lungs, heart, bones, brain, stomach, intestine, pancreas, skin, muscle and tumor were found to be 3.1 %ID/g, 2.8 %ID/g, 1.8 %ID/g, 0.9 %ID/g, 0.3 %ID/g, 1.2 %ID/g, 1.8 %ID/g, 1.2 %ID/g, 1.0 %ID/g, 0.6 %ID/g and 3.4 %ID/g, respectively. Significant variability in nanoparticle distribution was observed in certain organs such as liver, spleen and lungs. A large fraction of this variability could be explained by accounting for the differences in nanoparticle physicochemical properties such as size and material. A critical overview of published nanoparticle physiologically-based pharmacokinetic (PBPK) models is provided, and limitations in our current knowledge about in vitro and in vivo pharmacokinetics of nanoparticles that restrict the development of robust PBPK models is also discussed. It is hypothesized that robust quantitative assessment of whole-body pharmacokinetics of nanoparticles and development of mathematical models that can predict their disposition can improve the probability of successful clinical translation of these modalities.

Spermidine/Spermine N1-Acetyltransferase 1 (SAT1)-A Potential Gene Target for Selective Sensitization of Glioblastoma Cells Using an Ionizable Lipid Nanoparticle to Deliver siRNA

Spermidine/spermine N1-acetyltransferase 1 (SAT1) responsible for cell polyamine catabolism is overexpressed in glioblastoma multiforme (GB). Its role in tumor survival and promoting resistance towards radiation therapy has made it an interesting target for therapy. In this study, we prepared a lipid nanoparticle-based siRNA delivery system (LNP-siSAT1) to selectively knockdown (KD) SAT1 enzyme in a human glioblastoma cell line. The LNP-siSAT1 containing ionizable DODAP lipid was prepared following a microfluidics mixing method and the resulting nanoparticles had a hydrodynamic size of around 80 nm and a neutral surface charge. The LNP-siSAT1 effectively knocked down the SAT1 expression in U251, LN229, and 42MGBA GB cells, and other brain-relevant endothelial (hCMEC/D3), astrocyte (HA) and macrophage (ANA-1) cells at the mRNA and protein levels. SAT1 KD in U251 cells resulted in a 40% loss in cell viability. Furthermore, SAT1 KD in U251, LN229 and 42MGBA cells sensitized them towards radiation and chemotherapy treatments. In contrast, despite similar SAT1 KD in other brain-relevant cells no significant effect on cytotoxic response, either alone or in combination, was observed. A major roadblock for brain therapeutics is their ability to cross the highly restrictive blood-brain barrier (BBB) presented by the brain microcapillary endothelial cells. Here, we used the BBB circumventing approach to enhance the delivery of LNP-siSAT1 across a BBB cell culture model. A cadherin binding peptide (ADTC5) was used to transiently open the BBB tight junctions to promote paracellular diffusion of LNP-siSAT1. These results suggest LNP-siSAT1 may provide a safe and effective method for reducing SAT1 and sensitizing GB cells to radiation and chemotherapeutic agents.

Pharmacokinetics of magnetic iron oxide nanoparticles for medical applications

Magnetic iron oxide nanoparticles (MNPs) have been under intense investigation for at least the last five decades as they show enormous potential for many biomedical applications, such as biomolecule separation, MRI imaging and hyperthermia. Moreover, a large area of research on these nanostructures is concerned with their use as carriers of drugs, nucleic acids, peptides and other biologically active compounds, often leading to the development of targeted therapies. The uniqueness of MNPs is due to their nanometric size and unique magnetic properties. In addition, iron ions, which, along with oxygen, are a part of the MNPs, belong to the trace elements in the body. Therefore, after digesting MNPs in lysosomes, iron ions are incorporated into the natural circulation of this element in the body, which reduces the risk of excessive storage of nanoparticles. Still, one of the key issues for the therapeutic applications of magnetic nanoparticles is their pharmacokinetics which is reflected in the circulation time of MNPs in the bloodstream. These characteristics depend on many factors, such as the size and charge of MNPs, the nature of the polymers and any molecules attached to their surface, and other. Since the pharmacokinetics depends on the resultant of the physicochemical properties of nanoparticles, research should be carried out individually for all the nanostructures designed. Almost every year there are new reports on the results of studies on the pharmacokinetics of specific magnetic nanoparticles, thus it is very important to follow the achievements on this matter. This paper reviews the latest findings in this field. The mechanism of action of the mononuclear phagocytic system and the half-lives of a wide range of nanostructures are presented. Moreover, factors affecting clearance such as hydrodynamic and core size, core morphology and coatings molecules, surface charge and technical aspects have been described.

Smart nanomaterials for cancer diagnosis and treatment

Innovations in nanomedicine has guided the improved outcomes for cancer diagnosis and therapy. However, frequent use of nanomaterials remains challenging due to specific limitations like non-targeted distribution causing low signal-to-noise ratio for diagnostics, complex fabrication, reduced-biocompatibility, decreased photostability, and systemic toxicity of nanomaterials within the body. Thus, better nanomaterial-systems with controlled physicochemical and biological properties, form the need of the hour. In this context, smart nanomaterials serve as promising solution, as they can be activated under specific exogenous or endogenous stimuli such as pH, temperature, enzymes, or a particular biological molecule. The properties of smart nanomaterials make them ideal candidates for various applications like biosensors, controlled drug release, and treatment of various diseases. Recently, smart nanomaterial-based cancer theranostic approaches have been developed, and they are displaying better selectivity and sensitivity with reduced side-effects in comparison to conventional methods. In cancer therapy, the smart nanomaterials-system only activates in response to tumor microenvironment (TME) and remains in deactivated state in normal cells, which further reduces the side-effects and systemic toxicities. Thus, the present review aims to describe the stimulus-based classification of smart nanomaterials, tumor microenvironment-responsive behaviour, and their up-to-date applications in cancer theranostics. Besides, present review addresses the development of various smart nanomaterials and their advantages for diagnosing and treating cancer. Here, we also discuss about the drug targeting and sustained drug release from nanocarriers, and different types of nanomaterials which have been engineered for this intent. Additionally, the present challenges and prospects of nanomaterials in effective cancer diagnosis and therapeutics have been discussed.

Albumin covering maintains endothelial function upon magnetic iron oxide nanoparticles intravenous injection in rats

Magnetic iron oxide nanoparticles (IONP) present the promising instrument for broad-spectrum of clinical applications, for example, targeted drug delivery. Reactivity of nanoparticles depends on their surface area and material. In the blood plasma IONP are getting covered with an albumin crown, so it was decided to test this shell for biocompatibility. Male Wistar rats were anesthetized and underwent laparotomy. Abdominal aorta was connected to external hemodynamic loop with regulated blood flow. Hind body quarter got step-like blood flow changing from 30 to 150 mmHg and back. This was followed with i.v. injection of IONP, albumin solution or albumin-covered IONP and consequent similar flow changes. Central hemodynamics-heart rate and mean arterial pressure were registered throughout the experiment and no significant changes in these parameters were observed. Hind paw microcirculation level had the same dynamic in all groups under changing blood flow conditions. At the end, venous blood was collected for endothelin-1 and NO evaluation that showed similar changes and no endothelial damage. Mesenteric arteries and femoral artery reactivity were evaluated with wire myography. Mesenteric arteries had the most relaxing function preservation after albumin-covered IONP injection. Given data reveal advantage of albumin-coated IONP so this can be used for further investigations as a vascular-safe vehicle.

Doxorubicin-loaded iron oxide nanoparticles for glioblastoma therapy: a combinational approach for enhanced delivery of nanoparticles

Although doxorubicin (DOX) is an effective anti-cancer drug with cytotoxicity in a variety of different tumors, its effectiveness in treating glioblastoma multiforme (GBM) is constrained by insufficient penetration across the blood–brain barrier (BBB). In this study, biocompatible magnetic iron oxide nanoparticles (IONPs) stabilized with trimethoxysilylpropyl-ethylenediamine triacetic acid (EDT) were developed as a carrier of DOX for GBM chemotherapy. The DOX-loaded EDT-IONPs (DOX-EDT-IONPs) released DOX within 4 days with the capability of an accelerated release in acidic microenvironments. The DOX-loaded EDT-IONPs (DOX-EDT-IONPs) demonstrated an efficient uptake in mouse brain-derived microvessel endothelial, bEnd.3, Madin–Darby canine kidney transfected with multi-drug resistant protein 1 (MDCK-MDR1), and human U251 GBM cells. The DOX-EDT-IONPs could augment DOX’s uptake in U251 cells by 2.8-fold and significantly inhibited U251 cell proliferation. Moreover, the DOX-EDT-IONPs were found to be effective in apoptotic-induced GBM cell death (over 90%) within 48 h of treatment. Gene expression studies revealed a significant downregulation of TOP II and Ku70, crucial enzymes for DNA repair and replication, as well as MiR-155 oncogene, concomitant with an upregulation of caspase 3 and tumor suppressors i.e., p53, MEG3 and GAS5, in U251 cells upon treatment with DOX-EDT-IONPs. An in vitro MDCK-MDR1-GBM co-culture model was used to assess the BBB permeability and anti-tumor activity of the DOX-EDT-IONPs and DOX treatments. While DOX-EDT-IONP showed improved permeability of DOX across MDCK-MDR1 monolayers compared to DOX alone, cytotoxicity in U251 cells was similar in both treatment groups. Using a cadherin binding peptide (ADTC5) to transiently open tight junctions, in combination with an external magnetic field, significantly enhanced both DOX-EDT-IONP permeability and cytotoxicity in the MDCK-MDR1-GBM co-culture model. Therefore, the combination of magnetic enhanced convective diffusion and the cadherin binding peptide for transiently opening the BBB tight junctions are expected to enhance the efficacy of GBM chemotherapy using the DOX-EDT-IONPs. In general, the developed approach enables the chemotherapeutic to overcome both BBB and multidrug resistance (MDR) glioma cells while providing site-specific magnetic targeting.

Versatile role of curcumin and its derivatives in lung cancer therapy

Lung cancer is a main cause of death all over the world with a high incidence rate. Metastasis into neighboring and distant tissues as well as resistance of cancer cells to chemotherapy demand novel strategies in lung cancer therapy. Curcumin is a naturally occurring nutraceutical compound derived from Curcuma longa (turmeric) that has great pharmacological effects, such as anti-inflammatory, neuroprotective, and antidiabetic. The excellent antitumor activity of curcumin has led to its extensive application in the treatment of various cancers. In the present review, we describe the antitumor activity of curcumin against lung cancer. Curcumin affects different molecular pathways such as vascular endothelial growth factors, nuclear factor-κB (NF-κB), mammalian target of rapamycin, PI3/Akt, microRNAs, and long noncoding RNAs in treatment of lung cancer. Curcumin also can induce autophagy, apoptosis, and cell cycle arrest to reduce the viability and proliferation of lung cancer cells. Notably, curcumin supplementation sensitizes cancer cells to chemotherapy and enhances chemotherapy-mediated apoptosis. Curcumin can elevate the efficacy of radiotherapy in lung cancer therapy by targeting various signaling pathways, such as epidermal growth factor receptor and NF-κB. Curcumin-loaded nanocarriers enhance the bioavailability, cellular uptake, and antitumor activity of curcumin. The aforementioned effects are comprehensively discussed in the current review to further direct studies for applying curcumin in lung cancer therapy.

Scope and Applications of Nanomedicines for the Management of Neuropathic Pain

Neuropathic pain, resulting from the dysfunction of the peripheral and central nervous system, occurs in a variety of pathological conditions including trauma, diabetes, cancer, HIV, surgery, multiple sclerosis, ischemic attack, alcoholism, spinal cord damage, and many others. Despite the availability of various treatment strategies, the percentage of patients achieving adequate pain relief remains low. The clinical failure of most effective drugs is often not due to a lack of drug efficacy but due to the dose-limiting central nervous system (CNS) toxicity of the drugs that preclude dose escalation. There is a need for cross-disciplinary collaborations to meet these challenges. In this regard, the integration of nanotechnology with neuroscience is one of the most important fields. In recent years, promising preclinical research has been reported in this field. This review highlights the current challenges associated with conventional neuropathic pain treatments, the scope for nanomaterials in delivering drugs across the blood-brain barrier, and the state and prospects of nanomaterials for the management of neuropathic pain.

Application of Iron Oxide Nanoparticles in the Diagnosis and Treatment of Neurodegenerative Diseases With Emphasis on Alzheimer's Disease

Neurodegenerative diseases are characterized by chronic progressive degeneration of the structure and function of the nervous system, which brings an enormous burden on patients, their families, and society. It is difficult to make early diagnosis, resulting from the insidious onset and progressive development of neurodegenerative diseases. The drugs on the market cannot cross the blood-brain barrier (BBB) effectively, which leads to unfavorable prognosis and less effective treatments. Therefore, there is an urgent demand to develop a novel detection method and therapeutic strategies. Recently, nanomedicine has aroused considerable attention for diagnosis and therapy of central nervous system (CNS) diseases. Nanoparticles integrate targeting, imaging, and therapy in one system and facilitate the entry of drug molecules across the blood-brain barrier, offering new hope to patients. In this review, we summarize the application of iron oxide nanoparticles (IONPs) in the diagnosis and treatment of neurodegenerative disease, including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). We focus on IONPs as magnetic resonance imaging (MRI) contrast agents (CAs) and drug carriers in AD. What most neurodegenerative diseases have in common is that hall marker lesions are represented by protein aggregates (Soto and Pritzkow, 2018). These diseases are of unknown etiology and unfavorable prognosis, and the treatments toward them are less effective (Soto and Pritzkow, 2018). Such diseases usually develop in aged people, and early clinical manifestations are atypical, resulting in difficulty in early diagnosis. Recently, nanomedicine has aroused considerable attention for therapy and diagnosis of CNS diseases because it integrates targeting, imaging, and therapy in one system (Gupta et al., 2019). In this review article, we first introduce the neurodegenerative diseases and commonly used MRI CAs. Then we review the application of IONPs in the diagnosis and treatment of neurodegenerative diseases with the purpose of assisting early theranostics (therapy and diagnosis).

Recent Advancements of Magnetic Nanomaterials in Cancer Therapy

Magnetic nanomaterials belong to a class of highly-functionalizable tools for cancer therapy owing to their intrinsic magnetic properties and multifunctional design that provides a multimodal theranostics platform for cancer diagnosis, monitoring, and therapy. In this review article, we have provided an overview of the various applications of magnetic nanomaterials and recent advances in the development of these nanomaterials as cancer therapeutics. Moreover, the cancer targeting, potential toxicity, and degradability of these nanomaterials has been briefly addressed. Finally, the challenges for clinical translation and the future scope of magnetic nanoparticles in cancer therapy are discussed.

Magnetic iron oxide nanoparticles for imaging, targeting and treatment of primary and metastatic tumors of the brain

Magnetic nanoparticles in general, and iron oxide nanoparticles in particular, have been studied extensively during the past 20 years for numerous biomedical applications. The main applications of these nanoparticles are in magnetic resonance imaging (MRI), magnetic targeting, gene and drug delivery, magnetic hyperthermia for tumor treatment, and manipulation of the immune system by macrophage polarization for cancer treatment. Recently, considerable attention has been paid to magnetic particle imaging (MPI) because of its better sensitivity compared to MRI. In recent years, MRI and MPI have been combined as a dual or multimodal imaging method to enhance the signal in the brain for the early detection and treatment of brain pathologies. Because magnetic and iron oxide nanoparticles are so diverse and can be used in multiple applications such as imaging or therapy, they have attractive features for brain delivery. However, the greatest limitations for the use of MRI/MPI for imaging and treatment are in brain delivery, with one of these limitations being the brain-blood barrier (BBB). This review addresses the current status, chemical compositions, advantages and disadvantages, toxicity and most importantly the future directions for the delivery of iron oxide based substances across the blood-brain barrier for targeting, imaging and therapy of primary and metastatic tumors of the brain.

Magnetic Nanoparticle Systems for Nanomedicine—A Materials Science Perspective

Iron oxide nanoparticles are the basic components of the most promising magneto-responsive systems for nanomedicine, ranging from drug delivery and imaging to hyperthermia cancer treatment, as well as to rapid point-of-care diagnostic systems with magnetic nanoparticles. Advanced synthesis procedures of single- and multi-core iron-oxide nanoparticles with high magnetic moment and well-defined size and shape, being designed to simultaneously fulfill multiple biomedical functionalities, have been thoroughly evaluated. The review summarizes recent results in manufacturing novel magnetic nanoparticle systems, as well as the use of proper characterization methods that are relevant to the magneto-responsive nature, size range, surface chemistry, structuring behavior, and exploitation conditions of magnetic nanosystems. These refer to particle size, size distribution and aggregation characteristics, zeta potential/surface charge, surface coating, functionalization and catalytic activity, morphology (shape, surface area, surface topology, crystallinity), solubility and stability (e.g., solubility in biological fluids, stability on storage), as well as to DC and AC magnetic properties, particle agglomerates formation, and flow behavior under applied magnetic field (magnetorheology).

Established and Emerging Strategies for Drug Delivery Across the Blood-Brain Barrier in Brain Cancer

Brain tumors are characterized by very high mortality and, despite the continuous research on new pharmacological interventions, little therapeutic progress has been made. One of the main obstacles to improve current treatments is represented by the impermeability of the blood vessels residing within nervous tissue as well as of the new vascular net generating from the tumor, commonly referred to as blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB), respectively. In this review, we focused on established and emerging strategies to overcome the blood-brain barrier to increase drug delivery for brain cancer. To date, there are three broad strategies being investigated to cross the brain vascular wall and they are conceived to breach, bypass, and negotiate the access to the nervous tissue. In this paper, we summarized these approaches highlighting their working mechanism and their potential impact on the quality of life of the patients as well as their current status of development.

Biodistribution and targeting properties of iron oxide nanoparticles for treatments of cancer and iron anemia disease

IONP (iron oxide nanoparticles) commercialized for treatments of iron anemia or cancer diseases can be administered at doses exceeding 1 g per patient, indicating their bio-compatibility when they are prepared in the right conditions. Various parameters influence IONP biodistribution such as nanoparticle size, hydrophobicity/hydrophilicity, surface charge, core composition, coating properties, route of administration, quantity administered, and opsonization. IONP biodistribution trends include their capture by the reticuloendothelial system (RES), accumulation in liver and spleen, leading to nanoparticle degradation by macrophages and liver Kupffer cells, possibly followed by excretion in feces. To result in efficient tumor treatment, IONP need to reach the tumor in a sufficiently large quantity, using: (i) passive targeting, i.e. the extravasation of IONP through the blood vessel irrigating the tumor, (ii) molecular targeting achieved by a ligand bound to IONP specifically recognizing a cell receptor, and (iii) magnetic targeting in which a magnetic field gradient guides IONP towards the tumor. As a whole, targeting efficacy is relatively similar for different targeting, yielding a percentage of injected IONP in the tumor of 5.10^-4% to 3%, 0.1% to 7%, and 5.10^-3% to 2.6% for passive, molecular, and magnetic targeting, respectively. For the treatment of iron anemia disease, IONP are captured by the RES, and dissolved into free iron, which is then made available for the organism. For the treatment of cancer, IONP either deliver chemotherapeutic drugs to tumors, produce localized heat under the application of an alternating magnetic field or a laser, or activate in a controlled manner a sono-sensitizer following ultrasound treatment.

Fabrication of magnetic nanochains linked with CTX and curcumin for dual modal imaging detection and limitation of early tumour

OBJECTIVE

Five-year survival rate at early lung tumour was about 70%; however, its early diagnosis rate was still at a low level, so the enhancement of diagnosis level for early lung tumour is the key factor to increase the survival rate. Diagnosis and therapy of early lung tumour are still challenged.

METHODS

The magnetic nanochains (NCs) with biocompatibility and transverse relaxivity (r2  = 231 Fe mmol l-1  s-1 ) were fabricated through a co-precipitation method in the assistance of dextran, and then, linked with chlorotoxin (CTX) and curcumin (Cur) via the PEGylation and carbodiimide technique (named as CTX-NCs-Cur).

RESULTS

The results of cell test indicated that CTX-conjugated NCs could obviously target non-small-cell lung cancer cells and limit their growth. The in vivo results of magnetic resonance imaging and fluorescence imaging indicated that the CTX-NCs-Cur significantly targeted the tumour site and enhanced images contrast of the small-size tumour. Moreover, the results of everyday tail-vein injection confirmed that CTX-NCs-Cur could significantly limit the growth of early tumour, due to blocking Cl ion channels from CTX-NCs-Cur-MMP-2 composite and intracellular ROS increase from Cur treatment.

CONCLUSIONS

We provided a mechanism about the effect of CTX-NCs-Cur on the targeting and limiting early tumour, and these results indicated the application foreground of CTX-NCs-Cur in tumour diagnosis and therapy.

A review of drug delivery systems based on nanotechnology and green chemistry: green nanomedicine

This review discusses the impact of green and environmentally safe chemistry on the field of nanotechnology-driven drug delivery in a new field termed "green nanomedicine". Studies have shown that among many examples of green nanotechnology-driven drug delivery systems, those receiving the greatest amount of attention include nanometal particles, polymers, and biological materials. Furthermore, green nanodrug delivery systems based on environmentally safe chemical reactions or using natural biomaterials (such as plant extracts and microorganisms) are now producing innovative materials revolutionizing the field. In this review, the use of green chemistry design, synthesis, and application principles and eco-friendly synthesis techniques with low side effects are discussed. The review ends with a description of key future efforts that must ensue for this field to continue to grow.

AM966, an Antagonist of Lysophosphatidic Acid Receptor 1, Increases Lung Microvascular Endothelial Permeability through Activation of Rho Signaling Pathway and Phosphorylation of VE-Cadherin

Maintenance of pulmonary endothelial barrier integrity is important for reducing severity of lung injury. Lysophosphatidic acid (LPA) regulates cell motility, cytoskeletal rearrangement, and cell growth. Knockdown of LPA receptor 1 (LPA1) has been shown to mitigate lung injury and pulmonary fibrosis. AM966, an LPA1 antagonist exhibiting an antifibrotic property, has been considered to be a future antifibrotic medicine. Here, we report an unexpected effect of AM966, which increases lung endothelial barrier permeability. An electric cell-substrate sensing (ECIS) system was used to measure permeability in human lung microvascular endothelial cells (HLMVECs). AM966 decreased the transendothelial electrical resistance (TEER) value immediately in a dose-dependent manner. VE-cadherin and f-actin double immunostaining reveals that AM966 increases stress fibers and gap formation between endothelial cells. AM966 induced phosphorylation of myosin light chain (MLC) through activation of RhoA/Rho kinase pathway. Unlike LPA treatment, AM966 had no effect on phosphorylation of extracellular signal-regulated kinases (Erk). Further, in LPA1 silencing cells, we observed that AM966-increased lung endothelial permeability as well as phosphorylation of VE-cadherin and focal adhesion kinase (FAK) were attenuated. This study reveals that AM966 induces lung endothelial barrier dysfunction, which is regulated by LPA1-mediated activation of RhoA/MLC and phosphorylation of VE-cadherin.