Phosphatidylserine-targeted liposome for enhanced glioma-selective imaging

Antibody Conjugated Nano-Enabled Drug Delivery Systems Against Brain Tumors

The use of antibody-conjugated nanoparticles for brain tumor treatment has gained significant attention in recent years. Nanoparticles functionalized with anti-transferrin receptor antibodies have shown promising results in facilitating nanoparticle uptake by endothelial cells of brain capillaries and post-capillary venules. This approach offers a potential alternative to the direct conjugation of biologics to antibodies. Furthermore, studies have demonstrated the potential of antibody-conjugated nanoparticles in targeting brain tumors, as evidenced by the specific binding of these nanoparticles to brain cancer cells. Additionally, the development of targeted nanoparticles designed to transcytoses the blood-brain barrier (BBB) to deliver small molecule drugs and therapeutic antibodies to brain metastases holds promise for brain tumor treatment. While the use of nanoparticles as a delivery method for brain cancer treatment has faced challenges, including the successful delivery of nanoparticles to malignant brain tumors due to the presence of the BBB and infiltrating cancer cells in the normal brain, recent advancements in nanoparticle-mediated drug delivery systems have shown potential for enhancing the efficacy of brain cancer therapy. Moreover, the development of brain-penetrating nanoparticles capable of distributing over clinically relevant volumes when administered via convection-enhanced delivery presents a promising strategy for improving drug delivery to brain tumors. In conclusion, the use of antibody-conjugated nanoparticles for brain tumor treatment shows great promise in overcoming the challenges associated with drug delivery to the brain. By leveraging the specific targeting capabilities of these nanoparticles, researchers are making significant strides in developing effective and targeted therapies for brain tumors.

Dysregulation of cellular membrane homeostasis as a crucial modulator of cancer risk

Cellular membranes serve as an epicentre combining extracellular and cytosolic components with membranous effectors, which together support numerous fundamental cellular signalling pathways that mediate biological responses. To execute their functions, membrane proteins, lipids and carbohydrates arrange, in a highly coordinated manner, into well-defined assemblies displaying diverse biological and biophysical characteristics that modulate several signalling events. The loss of membrane homeostasis can trigger oncogenic signalling. More recently, it has been documented that select membrane active dietaries (MADs) can reshape biological membranes and subsequently decrease cancer risk. In this review, we emphasize the significance of membrane domain structure, organization and their signalling functionalities as well as how loss of membrane homeostasis can steer aberrant signalling. Moreover, we describe in detail the complexities associated with the examination of these membrane domains and their association with cancer. Finally, we summarize the current literature on MADs and their effects on cellular membranes, including various mechanisms of dietary chemoprevention/interception and the functional links between nutritional bioactives, membrane homeostasis and cancer biology.

Autoantibodies specific for C1q, C3b, β2-glycoprotein 1 and annexins may amplify complement activity and reduce apoptosis-mediated immune suppression

Neoplastic cells hijack cell death pathways to evade the immune response. Phosphatidylserine, a marker of apoptotic cells, and its highly conserved bridging proteins, annexins and β2-glycoprotein I, facilitate the efficient removal of apoptotic and necrotic cells via tumor-associated phagocytes in a process called efferocytosis. Efferocytosis results in the clearance of dead and dying cells and local immune suppression. Neoplastic cells also have an increased capacity to activate complement. Complement may facilitate the silent removal of tumor cells and has a dual role in promoting and inhibiting tumor growth. Here I hypothesize that immune response-generating IgG autoantibodies that recognize opsonizing fragments C1q, C3b, and phosphatidylserine-binding proteins (annexins, β2-glycoprotein I) may reduce tumor growth. I propose that these autoantibodies induce a pro-inflammatory, cytotoxic tumor microenvironment. Further, I predict that autoantibodies can drive neoplastic cell phagocytosis in an Fc receptor-dependent manner and recruit additional complement, resulting in immune-stimulatory effects. Excessive complement activation and antibody-dependent cytotoxicity may stimulate anti-tumor responses, including damage to tumor vasculature. Here I provide insights that may aid the development of more effective therapeutic modalities to control cancer. Such therapeutic approaches should kill neoplastic cells and target their interaction with host immune cells. Thereby the pro-tumorigenic effect of dead cancer cells could be limited while inducing the anti-tumor potential of tumor-associated phagocytes.

Contrast Agents Delivery: An Up-to-Date Review of Nanodiagnostics in Neuroimaging

Neuroimaging is a highly important field of neuroscience, with direct implications for the early diagnosis and progression monitoring of brain-associated diseases. Neuroimaging techniques are categorized into structural, functional and molecular neuroimaging, each possessing advantages and disadvantages in terms of resolution, invasiveness, toxicity of contrast agents and costs. Nanotechnology-based approaches for neuroimaging mostly involve the development of nanocarriers for incorporating contrast agents or the use of nanomaterials as imaging agents. Inorganic and organic nanoparticles, liposomes, micelles, nanobodies and quantum dots are some of the most studied candidates for the delivery of contrast agents for neuroimaging. This paper focuses on describing the conventional modalities used for imaging and the applications of nanotechnology for developing novel strategies for neuroimaging. The aim is to highlight the roles of nanocarriers for enhancing and/or overcome the limitations associated with the most commonly utilized neuroimaging modalities. For future directions, several techniques that could benefit from the increased contrast induced by using imaging probes are presented.

Functional link between plasma membrane spatiotemporal dynamics, cancer biology, and dietary membrane-altering agents

The cell plasma membrane serves as a nexus integrating extra- and intracellular components, which together enable many of the fundamental cellular signaling processes that sustain life. In order to perform this key function, plasma membrane components assemble into well-defined domains exhibiting distinct biochemical and biophysical properties that modulate various signaling events. Dysregulation of these highly dynamic membrane domains can promote oncogenic signaling. Recently, it has been demonstrated that select membrane-targeted dietary bioactives (MTDBs) have the ability to remodel plasma membrane domains and subsequently reduce cancer risk. In this review, we focus on the importance of plasma membrane domain structural and signaling functionalities as well as how loss of membrane homeostasis can drive aberrant signaling. Additionally, we discuss the intricacies associated with the investigation of these membrane domain features and their associations with cancer biology. Lastly, we describe the current literature focusing on MTDBs, including mechanisms of chemoprevention and therapeutics in order to establish a functional link between these membrane-altering biomolecules, tuning of plasma membrane hierarchal organization, and their implications in cancer prevention.

Neuronanomedicine: An Up-to-Date Overview

The field of neuronanomedicine has recently emerged as the bridge between neurological sciences and nanotechnology. The possibilities of this novel perspective are promising for the diagnosis and treatment strategies of severe central nervous system disorders. Therefore, the development of nano-vehicles capable of permeating the blood⁻brain barrier (BBB) and reaching the brain parenchyma may lead to breakthrough therapies that could improve life expectancy and quality of the patients diagnosed with brain disorders. The aim of this review is to summarize the recently developed organic, inorganic, and biological nanocarriers that could be used for the delivery of imaging and therapeutic agents to the brain, as well as the latest studies on the use of nanomaterials in brain cancer, neurodegenerative diseases, and stroke. Additionally, the main challenges and limitations associated with the use of these nanocarriers are briefly presented.

Photodynamic opening of the blood-brain barrier to high weight molecules and liposomes through an optical clearing skull window

The photodynamic (PD) effect has been reported to be efficient for the opening of the blood-brain barrier (BBB), which provides a new informative platform for developing perspective strategies towards brain disease therapy and drug delivery. However, this method is usually performed via craniotomy due to high scattering of the turbid skull. In this work, we employed a newly-developed optical clearing skull window for investigating non-invasive PD-induced BBB opening to high weight molecules and 100-nm fluid-phase liposomes containing ganglioside GM1. The results demonstrated that the BBB permeability to the Evans blue albumin complex is related to laser doses. By in vivo two-photon imaging and ex vivo confocal imaging with specific markers of the BBB, we noticed PD-related extravasation of rhodamine-dextran and liposomes from the vessels into the brain parenchyma. The PD induced an increase in oxidative stress associated with mild hypoxia and changes in the expression of tight junction (CLND-5 and ZO-1) and adherens junction (VE-cadherin) proteins, which might be one of the mechanisms underlying the PD-related BBB opening for liposomes. Our experiments indicate that optical clearing skull window will be a promising tool for non-invasive PD-related BBB opening for high weight molecules and liposomes that provides a novel useful tool for brain drug delivery and treatment of brain diseases.

Phosphatidylserine-Targeted Nanotheranostics for Brain Tumor Imaging and Therapeutic Potential

Phosphatidylserine (PS), the most abundant anionic phospholipid in cell membrane, is strictly confined to the inner leaflet in normal cells. However, this PS asymmetry is found disruptive in many tumor vascular endothelial cells. We discuss the underlying mechanisms for PS asymmetry maintenance in normal cells and its loss in tumor cells. The specificity of PS exposure in tumor vasculature but not normal blood vessels may establish it a useful biomarker for cancer molecular imaging. Indeed, utilizing PS-targeting antibodies, multiple imaging probes have been developed and multimodal imaging data have shown their high tumor-selective targeting in various cancers. There is a critical need for improved diagnosis and therapy for brain tumors. We have recently established PS-targeted nanoplatforms, aiming to enhance delivery of imaging contrast agents across the blood-brain barrier to facilitate imaging of brain tumors. Advantages of using the nanodelivery system, in particular, lipid-based nanocarriers, are discussed here. We also describe our recent research interest in developing PS-targeted nanotheranostics for potential image-guided drug delivery to treat brain tumors.

P1c peptide decorated liposome targeting αvβ3-expressing tumor cellsin vitroandin vivo

Integrin αvβ3 is a promising target for integrin-rich tumor and neovascular. In the present study, we prepared a doxorubicin (DOX)-loaded liposome of which the surface was decorated with PEG and a novel αvβ3 targeting peptide of P1c. The in vitro targeting efficiency was evaluated in αvβ3-positive (U87MG) and -negative (MCF-7) tumor cells by flow cytometry and laser confocal scanning microscopy. The in vivo therapeutic effects were evaluated in the glioblastoma U87MG-tumor bearing mouse model. The results indicated that the prepared liposomes showed mean sizes of 131.2 and 128.4 nm in diameter for P1c-modified targeting liposomes (P1c-DOXL) and non-targeting liposomes (DOXL), respectively. The DOX encapsulation efficiencies were more than 95% in both types of liposomes. The conjugation ratio for P1c decoration was 66.8%. The flow cytometry and confocal laser-scanning microscopy experiments consistently showed that the intracellular fluorescence intensity of the P1c-modified targeted liposome group was stronger than that of the non-targeted liposome group (P < 0.05) in U87MG cells. In vivo results revealed that compared with DOX or DOXL treatment, P1c-DOXL dramatically reduced tumor growth (P < 0.05) and tumor angiogenesis while much lower hepatotoxicity was observed. P1c-modified targeting liposome exhibited sustained release, enhancing the antitumor effect of DOX through targeting tumor cells and neovascular where integrin αvβ3 was overexpressed. The results indicated that P1c might be promising for active targeting delivery in cancer therapy.

A novel peptide of P1c decorated liposomes targets an integrin αvβ3 expressed tumor.

Covalent nano delivery systems for selective imaging and treatment of brain tumors

Nanomedicine is a rapidly evolving form of therapy that holds a great promise for superior drug delivery efficiency and therapeutic efficacy than conventional cancer treatment. In this review, we attempt to cover the benefits and the limitations of current nanomedicines with special attention to covalent nano conjugates for imaging and drug delivery in the brain. The improvement in brain tumor treatment remains dismal despite decades of efforts in drug development and patient care. One of the major obstacles in brain cancer treatment is the poor drug delivery efficiency owing to the unique blood-brain barrier (BBB) in the CNS. Although various anti-cancer agents are available to treat tumors outside of the CNS, the majority fails to cross the BBB. In this regard, nanomedicines have increasingly drawn attention due to their multi-functionality and versatility. Nano drugs can penetrate BBB and other biological barriers, and selectively accumulate in tumor cells, while concurrently decreasing systemic toxicity.