Novel antisense therapeutics delivery systems: In vitro and in vivo studies of liposomes targeted with anti-CD20 antibody

Oligonucleotide probes for imaging and diagnosis of bacterial infections

The rise of infectious diseases as a public health concern has necessitated the development of rapid and precise diagnostic methods. Imaging techniques like nuclear and optical imaging provide the ability to diagnose infectious diseases within the body, eliminating delays caused by sampling and pre-enrichments of clinical samples and offering spatial information that can aid in a more informed diagnosis. Traditional molecular probes are typically created to image infected tissue without accurately identifying the pathogen. In contrast, oligonucleotides can be tailored to target specific RNA sequences, allowing for the identification of pathogens, and even generating antibiotic susceptibility profiles by focusing on drug resistance genes. Despite the benefits that nucleic acid mimics (NAMs) have provided in terms of stabilizing oligonucleotides, the inadequate delivery of these relatively large molecules into the cytoplasm of bacteria remains a challenge for widespread use of this technology. This review summarizes the key advancements in the field of oligonucleotide probes for in vivo imaging, highlighting the most promising delivery systems described in the literature for developing optical imaging through in vivo hybridization.

Valrubicin-loaded immunoliposomes for specific vesicle-mediated cell death in the treatment of hematological cancers

We created valrubicin-loaded immunoliposomes (Val-ILs) using the antitumor prodrug valrubicin, a hydrophobic analog of daunorubicin. Being lipophilic, valrubicin readily incorporated Val-lLs that were loaded with specific antibodies. Val-ILs injected intravenously rapidly reached the bone marrow and spleen, indicating their potential to effectively target cancer cells in these areas. Following the transplantation of human pediatric B-cell acute lymphoblastic leukemia (B-ALL), T-cell acute lymphoblastic leukemia (T-ALL), or acute myeloid leukemia (AML) in immunodeficient NSG mice, we generated patient-derived xenograft (PDX) models, which were treated with Val-ILs loaded with antibodies to target CD19, CD7 or CD33. Only a small amount of valrubicin incorporated into Val-ILs was needed to induce leukemia cell death in vivo, suggesting that this approach could be used to efficiently treat acute leukemia cells. We also demonstrated that Val-ILs could reduce the risk of contamination of CD34+ hematopoietic stem cells by acute leukemia cells during autologous peripheral blood stem cell transplantation, which is a significant advantage for clinical applications. Using EL4 lymphoma cells on immunocompetent C57BL/6 mice, we also highlighted the potential of Val-ILs to target immunosuppressive cell populations in the spleen, which could be valuable in impairing cancer cell expansion, particularly in lymphoma cases. The most efficient Val-ILs were found to be those loaded with CD11b or CD223 antibodies, which, respectively, target the myeloid-derived suppressor cells (MDSC) or the lymphocyte-activation gene 3 (LAG-3 or CD223) on T4 lymphocytes. This study provides a promising preclinical demonstration of the effectiveness and ease of preparation of Val-ILs as a novel nanoparticle technology. In the context of hematological cancers, Val-ILs have the potential to be used as a precise and effective therapy based on targeted vesicle-mediated cell death.

Engineering aspects of lipid-based delivery systems: In vivo gene delivery, safety criteria, and translation strategies

Defects in the genome cause genetic diseases and can be treated with gene therapy. Due to the limitations encountered in gene delivery, lipid-based supramolecular colloidal materials have emerged as promising gene carrier systems. In their non-functionalized form, lipid nanoparticles often demonstrate lower transgene expression efficiency, leading to suboptimal therapeutic outcomes, specifically through reduced percentages of cells expressing the transgene. Due to chemically active substituents, the engineering of delivery systems for genetic drugs with specific chemical ligands steps forward as an innovative strategy to tackle the drawbacks and enhance their therapeutic efficacy. Despite intense investigations into functionalization strategies, the clinical outcome of such therapies still needs to be improved. Here, we highlight and comprehensively review engineering aspects for functionalizing lipid-based delivery systems and their therapeutic efficacy for developing novel genetic cargoes to provide a full snapshot of the translation from the bench to the clinics. We outline existing challenges in the delivery and internalization processes and narrate recent advances in the functionalization of lipid-based delivery systems for nucleic acids to enhance their therapeutic efficacy and safety. Moreover, we address clinical trials using these vectors to expand their clinical use and principal safety concerns.

Lipid-Polymer Hybrid Nanoparticles with Both PD-L1 Knockdown and Mild Photothermal Effect for Tumor Photothermal Immunotherapy

In developing countries, the incidence of colorectal cancer (CRC) is on the rise. The combination of programmed cell death ligand-1 (PD-L1) siRNA (siPD-L1) and mild photothermal therapy (PTT) is a promising strategy for CRC treatment. In this study, dopamine-modified polyethylenimine (PEI) was prepared to fabricate an IR780 and siPD-L1 codelivery lipid-polymer hybrid nanoparticle (lip@PSD-siP) for the photothermal immunotherapy of CRC. The modification of dopamine can significantly reduce the cytotoxicity of PEI. lip@PSD-siP can be effectively taken up by CT26 cells and successfully escaped from lysosomes after entering the cells for 4 h. After CT26 cells were transfected with lip@PSD-siP, the PD-L1 positive cell rate decreased by 82.4%, and its PD-L1 knockdown effect was significantly stronger than the positive control Lipo3000-siP. In vivo studies showed that lip@PSD-siP-mediated mild PTT and efficient PD-L1 knockdown exhibited primary and distal tumor inhibition, metastasis delay, and rechallenged tumor inhibition. The treatment with lip@PSD-siP significantly promoted the maturation of dendritic cells in lymph nodes. The amount of T cell infiltration in the tumor tissues increased significantly, and the frequency of CD8+ T cells and CD4+ T cells was significantly higher than that of other groups. The percentage of immunosuppressive regulatory cells (Tregs) in the tumor tissue on the treatment side decreased by 88% compared to the PBS group, and the proportion of CD8+CD69+ T cells in the distal tumor tissue was 2.8 times that of the PBS group. The memory T cells of mice in the long-term antitumor model were analyzed. The results showed that after treatment with lip@PSD-siP, the frequency of effector memory T cells (Tem cells) significantly increased, suggesting the formation of immune memory.

Targeted chitosan nanobubbles as a strategy to down-regulate microRNA-17 into B-cell lymphoma models

Introduction

MicroRNAs represent interesting targets for new therapies because their altered expression influences tumor development and progression. miR-17 is a prototype of onco-miRNA, known to be overexpressed in B-cell non-Hodgkin lymphoma (B-NHL) with peculiar clinic-biological features. AntagomiR molecules have been largely studied to repress the regulatory functions of up-regulated onco-miRNAs, but their clinical use is mainly limited by their rapid degradation, kidney elimination and poor cellular uptake when injected as naked oligonucleotides.

Methods

To overcome these problems, we exploited CD20 targeted chitosan nanobubbles (NBs) for a preferential and safe delivery of antagomiR17 to B-NHL cells.

Results

Positively charged 400 nm-sized nanobubbles (NBs) represent a stable and effective nanoplatform for antagomiR encapsulation and specific release into B-NHL cells. NBs rapidly accumulated in tumor microenvironment, but only those conjugated with a targeting system (antiCD20 antibodies) were internalized into B-NHL cells, releasing antagomiR17 in the cytoplasm, both in vitro and in vivo. The result is the down-regulation of miR-17 level and the reduction in tumor burden in a human-mouse B-NHL model, without any documented side effects.

Discussion

Anti-CD20 targeted NBs investigated in this study showed physico-chemical and stability properties suitable for antagomiR17 delivery in vivo and represent a useful nanoplatform to address B-cell malignancies or other cancers through the modification of their surface with specific targeting antibodies.

Versatility of Liposomes for Antisense Oligonucleotide Delivery: A Special Focus on Various Therapeutic Areas

Nucleic acid therapeutics, specifically antisense oligonucleotides (ASOs), can effectively modulate gene expression and protein function, leading to long-lasting curative effects. The hydrophilic nature and large size of oligonucleotides present translational challenges, which have led to the exploration of various chemical modifications and delivery systems. The present review provides insights into the potential role of liposomes as a drug delivery system for ASOs. The potential benefits of liposomes as an ASO carrier, along with their method of preparation, characterization, routes of administration, and stability aspects, have been thoroughly discussed. A novel perspective in terms of therapeutic applications of liposomal ASO delivery in several diseases such as cancer, respiratory disease, ophthalmic delivery, infectious diseases, gastrointestinal disease, neuronal disorders, hematological malignancies, myotonic dystrophy, and neuronal disorders remains the major highlights of this review.

Polyethyleneimine-Based Lipopolyplexes as Carriers in Anticancer Gene Therapies

Recent years have witnessed rapidly growing interest in application of gene therapies for cancer treatment. However, this strategy requires nucleic acid carriers that are both effective and safe. In this context, non-viral vectors have advantages over their viral counterparts. In particular, lipopolyplexes—nanocomplexes consisting of nucleic acids condensed with polyvalent molecules and enclosed in lipid vesicles—currently offer great promise. In this article, we briefly review the major aspects of developing such non-viral vectors based on polyethyleneimine and outline their properties in light of anticancer therapeutic strategies. Finally, examples of current in vivo studies involving such lipopolyplexes and possibilities for their future development are presented.

Fibrinspecific liposomes as a potential method of delivery of the thrombolytic preparation streptokinase

The use of streptokinase (SK) in the clinic is limited by the lack of fibrin-specificity and the short half-life of the drug. We have developed a new dosage form of streptokinase (immunoliposome), which consists of "free" native streptokinase and "bound" encapsulated in liposomes conjugated through carboxylated dextran with fibrin-specific monoclonal antibodies FnI-3C (IgG2 class), in a ratio of 60 and 40%, respectively, and studied their physicochemical properties, pharmacokinetic parameters, and the ability of fibrin-specific liposomes with SK for targeted delivery to fibrin in an in vivo experiment. The obtained immunoliposomes had a hydrodynamic diameter of ~ 140 nm, a zeta potential of - 19.6 mV, and entrapment efficiency of 14.1%. Fluorescent labels bound to immunoliposomes with streptokinase selectively accumulated in model rat vein thrombi at sites containing fibrin in 30 min after injection. Studies of pharmacokinetic parameters showed that the administration of immunoliposomes with streptokinase to rats was accompanied by an increase in the half-life from 1.8 to 24.1 min, the time to reach the maximum concentration from 15 to 30 min, and a decrease in the elimination constant by about 13 times compared with the native streptokinase preparation. Further studies are needed to evaluate the thrombolytic efficacy a new dosage form of streptokinase in experiment in vivo.

Delivery of small interfering RNAs by nanovesicles for cancer therapy

Small interfering ribonucleic acids (siRNAs) are originally recognized as an intermediate of the RNA interference (RNAi) pathway. They can inhibit or silence various cellular pathways by knocking down specific messenger RNA molecules. In cancer cells, siRNAs can suppress the expression of several multidrug-resistant genes, leading to the increased deposition of chemotherapeutic drugs at the tumor site. siRNA therapy can be used to selectively increase apoptosis of cancer cells or activate an immune response to the cancer. However, delivering siRNAs to the targeted location is the main limitation in achieving safe and effective delivery of siRNAs. This review highlights some representative examples of nonviral delivery systems, especially nanovesicles such as exosomes, liposomes, and niosomes. Nanovesicles can improve the delivery of siRNAs by increasing their intracellular delivery, and they have demonstrated excellent potential for cancer therapy. This review focuses on recent discoveries of siRNA targets for cancer therapy and the use of siRNAs to successfully silence these targets. In addition, this review summarizes the recent progress in designing nanovesicles (liposomes or niosomes) for siRNA delivery to cancer cells and the effects of a combination of anticancer drugs and siRNA therapy in cancer therapy.

Innovations in Biomaterial Design toward Successful RNA Interference Therapy for Cancer Treatment

Gene regulation using RNA interference (RNAi) therapy has been developed as one of the frontiers in cancer treatment. The ability to tailor the expression of genes by delivering synthetic oligonucleotides to tumor cells has transformed the way scientists think about treating cancer. However, its clinical application has been limited due to the need to deliver synthetic RNAi oligonucleotides efficiently and effectively to target cells. Advances in nanotechnology and biomaterials have begun to address the limitations to RNAi therapeutic delivery, increasing the likelihood of RNAi therapeutics for cancer treatment in clinical settings. Herein, innovations in the design of nanocarriers for the delivery of oligonucleotides for successful RNAi therapy are discussed.

Functionalized liposomes as drug nanocarriers for active targeted cancer therapy: a systematic review

Cancer is a broad term used to describe a group of diseases that have more than 270 types. Today, due to the suffering of patients from the side effects of existing methods in the treatment of cancer such as chemotherapy and radiotherapy, the employment of targeted methods in the treatment of this disease has been received much consideration. In recent years, nanoparticles have revolutionized in the treatment of many diseases such as cancer. Among these nanoparticles, liposomes are more considerable. Active targeted liposomes show an important role in the selective action of the drug on cancer cells. Until now, a variety of anti-cancer agents have been reported for targeted delivery to cancer cells using liposomes. The results of in vitro and studies in vivo have been shown that selective action of the targeted liposomes is increased with reduced side effects and toxicity compared with free drugs or non-targeted liposomes. This systematic review expresses the reports of this type of drug delivery system. Search terms were searched through several online databases including PubMed, Scopus, and Science Direct from 1990 to 2019 and the quality evaluation was performed. Out of 11,676 published articles, 196 articles met the inclusion criteria. The current report reviews developments in the liposomes targeted with aptamer, transferrin, folate, and monoclonal antibodies.

microRNAs as Novel Therapeutics in Cancer

Simple Summary

Over the last few years, we have witnessed incredible advancements in anti-tumor drug development. microRNAs, a class of small non-coding RNAs dysregulated in all cancers, have been recently elected as candidate therapeutics for treating a variety of diseases, including cancer. The scope of this review is to give some insight into the role of the most relevant microRNAs in cancer. We will focus on examining their biological role in tumor development while also providing a broad overview of microRNAs as therapeutics. There is a dedicated focus on the different methods available for microRNA delivery in addition to the efforts being made to increase the specificity of these delivery methods. Finally, we discuss the ongoing clinical trials that are using microRNAs for cancer treatment.

Abstract

In the last 20 years, the functional roles for miRNAs in gene regulation have been well established. MiRNAs act as regulators in virtually all biological pathways and thus have been implicated in numerous diseases, including cancer. They are particularly relevant in regulating the basic hallmarks of cancer, including apoptosis, proliferation, migration, and invasion. Despite the substantial progress made in identifying the molecular mechanisms driving the deregulation of miRNAs in cancer, the clinical translation of these important molecules to therapy remains in its infancy. The paucity of vehicles available for the safe and efficient delivery of miRNAs and ongoing concerns for toxicity remain major obstacles to clinical application. Novel formulations and the development of new vectors have significantly improved the stability of oligonucleotides, increasing the effectiveness of therapy. Furthermore, the use of specific moieties for delivery in target tissues or cells has increased the specificity of treatment. The use of new technologies has allowed small but important steps toward more specific therapeutic delivery in tumor tissues and cells. Although a long road remains, the path ahead holds great potential. Currently, a few miRNA drugs are under investigation in human clinical trials with promising results ahead.

Building Blocks to Design Liposomal Delivery Systems

The flexibility of liposomal carriers does not just simply rely on their capability to encapsulate various types of therapeutic substances, but also on the large array of components used for designing liposome-based nanoformulations. Each of their components plays a very specific role in the formulation and can be easily replaced whenever a different therapeutic effect is desired. It is tempting to describe this by an analogy to Lego blocks, since a whole set of structures, differing in their features, can be designed using a certain pool of blocks. In this review, we focus on different design strategies, where a broad variety of liposomal components facilitates the attainment of straightforward control over targeting and drug release, which leads to the design of the most promising systems for drug delivery. The key aspects of this block-based architecture became evident after its implementation in our recent works on liposomal carriers of antisense oligonucleotides and statins, which are described in the last chapter of this review.

The Effects of Single Nucleotide Polymorphisms in Cancer RNAi Therapies

Simple Summary

Despite the recent progress in RNAi delivery of siRNA-based therapeutics for cancer therapy, the presence of single nucleotide polymorphisms (SNPs) in the general population could dramatically reduce the effectiveness of RNAi therapy. Their ubiquitous presence can also lead to unpredictable and adverse side effects. Because both SNPs and somatic mosaicisms have also been implicated in a number of human diseases including cancer, however, these specific changes offer the ability to selectively and efficiently target cancer cells. Here, we discuss how SNPs influence the development and success of novel anticancer RNAi therapies.

Abstract

Tremendous progress in RNAi delivery methods and design has allowed for the effective development of siRNA-based therapeutics that are currently under clinical investigation for various cancer treatments. This approach has the potential to revolutionize cancer therapy by providing the ability to specifically downregulate or upregulate the mRNA of any protein of interest. This exquisite specificity, unfortunately, also has a downside. Genetic variations in the human population are common because of the presence of single nucleotide polymorphisms (SNPs). SNPs lead to synonymous and non-synonymous changes and they occur once in every 300 base pairs in both coding and non-coding regions in the human genome. Much less common are the somatic mosaicism variations associated with genetically distinct populations of cells within an individual that is derived from postzygotic mutations. These heterogeneities in the population can affect the RNAi’s efficacy or more problematically, which can lead to unpredictable and sometimes adverse side effects. From a more positive viewpoint, both SNPs and somatic mosaicisms have also been implicated in human diseases, including cancer, and these specific changes could offer the ability to effectively and, more importantly, selectively target the cancer cells. In this review, we discuss how SNPs in the human population can influence the development and success of novel anticancer RNAi therapies and the importance of why SNPs should be carefully considered.

Dual-Modified Liposome for Targeted and Enhanced Gene Delivery into Mice Brain

The development of neuropharmaceutical gene delivery systems requires strategies to obtain efficient and effective brain targeting as well as blood-brain barrier (BBB) permeability. A brain-targeted gene delivery system based on a transferrin (Tf) and cell-penetrating peptide (CPP) dual-functionalized liposome, CPP-Tf-liposome, was designed and investigated for crossing BBB and permeating into the brain. We selected three sequences of CPPs [melittin, Kaposi fibroblast growth factor (kFGF), and penetration accelerating sequence-R8] and compared their ability to internalize into the cells and, subsequently, improve the transfection efficiency. Study of intracellular uptake indicated that liposomal penetration into bEnd.3 cells, primary astrocytes, and primary neurons occurred through multiple endocytosis pathways and surface modification with Tf and CPP enhanced the transfection efficiency of the nanoparticles. A coculture in vitro BBB model reproducing the in vivo anatomophysiological complexity of the biologic barrier was developed to characterize the penetrating properties of these designed liposomes. The dual-functionalized liposomes effectively crossed the in vitro barrier model followed by transfecting primary neurons. Liposome tissue distribution in vivo indicated superior ability of kFGF-Tf-liposomes to overcome BBB and reach brain of the mice after single intravenous administration. These findings demonstrate the feasibility of using strategically designed liposomes by combining Tf receptor targeting with enhanced cell penetration as a potential brain gene delivery vector. SIGNIFICANCE STATEMENT: Rational synthesis of efficient brain-targeted gene carrier included modification of liposomes with a target-specific ligand, transferrin, and with cell-penetrating peptide to enhance cellular internalization. Our study used an in vitro triple coculture blood-brain barrier (BBB) model as a tool to characterize the permeability across BBB and functionality of designed liposomes prior to in vivo biodistribution studies. Our study demonstrated that rational design and characterization of BBB permeability are efficient strategies for development of brain-targeted gene carriers.

Endocytosis in cellular uptake of drug delivery vectors: Molecular aspects in drug development

Drug delivery vectors are widely applied to increase drug efficacy while reducing the side effects and potential toxicity of a drug. They allow for patient-tailored therapy, dose titration, and therapeutic drug monitoring. A major part of drug delivery systems makes use of large nanocarriers: liposomes or virus-like particles (VLPs). These systems allow for a relatively large amount of cargo with good stability of vectors, and they offer multiple options for targeting vectors in vivo. Here we discuss endocytic pathways that are available for drug delivery by large nanocarriers. We focus on molecular aspects of the process, including an overview of potential molecular targets for studies of drug delivery vectors and for future solutions allowing targeted drug delivery.

Combined Hydrophobization of Polyethylenimine with Cholesterol and Perfluorobutyrate Improves siRNA Delivery

Polyethylenimine (PEI) is a promising delivery vector of nucleic acids, but cytotoxicity and only moderate transfection efficacy with small RNAs limit its applications. Here we hypothesized that hydrophobization of PEI by combined modification with perfluorinated moieties (F) and cholesterol (Ch) will help in addressing both the cytotoxicity and siRNA delivery efficacy. To test the hypothesis, we synthesized a series of copolymers (F-PEI-Ch) by modifying PEI by reaction with heptafluorobutyric anhydride and cholesteryl chloroformate. We investigated and compared the effect of the modifications on siRNA delivery in vitro and in vivo. We found that the F-PEI-Ch copolymers assembled into micellar structures and that the copolymer with the highest Ch content exhibited the best siRNA delivery performance, including lower cytotoxicity, enhanced cell uptake, improved endosomal escape, and the best siRNA silencing efficacy in vitro and in vivo when compared with control PEI, F-PEI, and PEI-Ch. Overall, hydrophobization of PEI with a combination of cholesterol and superhydrophobic perfluorinated moieties represents a promising approach to the design of siRNA delivery vectors with decreased toxicity and enhanced transfection efficacy.

MicroRNA dysregulation interplay with childhood abdominal tumors

Abdominal tumors (AT) in children account for approximately 17% of all pediatric solid tumor cases, and frequently exhibit embryonal histological features that differentiate them from adult cancers. Current molecular approaches have greatly improved the understanding of the distinctive pathology of each tumor type and enabled the characterization of novel tumor biomarkers. As seen in abdominal adult tumors, microRNAs (miRNAs) have been increasingly implicated in either the initiation or progression of childhood cancer. Moreover, besides predicting patient prognosis, they represent valuable diagnostic tools that may also assist the surveillance of tumor behavior and treatment response, as well as the identification of the primary metastatic sites. Thus, the present study was undertaken to compile up-to-date information regarding the role of dysregulated miRNAs in the most common histological variants of AT, including neuroblastoma, nephroblastoma, hepatoblastoma, hepatocarcinoma, and adrenal tumors. Additionally, the clinical implications of dysregulated miRNAs as potential diagnostic tools or indicators of prognosis were evaluated.

Editorial focus: understanding off-target effects as the key to successful RNAi therapy

With the first RNA interference (RNAi) drug (ONPATTRO (patisiran)) on the market, we witness the RNAi therapy field reaching a critical turning point, when further improvements in drug candidate design and delivery pipelines should enable fast delivery of novel life changing treatments to patients. Nevertheless, ignoring parallel development of RNAi dedicated in vitro pharmacological profiling aiming to identify undesirable off-target activity may slow down or halt progress in the RNAi field. Since academic research is currently fueling the RNAi development pipeline with new therapeutic options, the objective of this article is to briefly summarize the basics of RNAi therapy, as well as to discuss how to translate basic research into better understanding of related drug candidate safety profiles early in the process.

EGFR-targeted immunoliposomes as a selective delivery system of simvastatin, with potential use in treatment of triple-negative breast cancers

A promising strategy for treatment of EGFR-dependent tumours is EGFR signal transduction suppression via inhibition of HMG-CoA reductase using high doses of statins, popular cholesterol-lowering drugs. The main purpose of this study was to obtain targeted long circulating immunoliposomes containing simvastatin (tLCLS) with anti-EGFR antibody attached to their surface and to test whether they can be effective in treatment of TNBC. The designed tLCLS were characterized in terms of physicochemical properties and long-term stability. In vitro experiments conducted on MDA-MB-231 cells demonstrated that tLCLS induced apoptosis and are characterized by IC₅₀ of 7.5 µM. Treatment of studied cells with tLCLS led to a decrease in membrane order and inhibited PI3K/Akt signalling. Analyses of efficacy of the tLCLS in in vivo experiments in model animals indicate that immunoliposomes were effectively delivered to tumours. Our results showed that regardless of whether tLCLS were administered before or after tumour formation, at the tested dose they inhibited tumour growth by an average of 25% in comparison to the control. However, the results were not statistically significant. The experiments described above allowed us to test the possibility of using immunoliposomes as simvastatin carriers delivering increased amounts of the drug to tumour cells.

PEGylated immunoliposome-loaded endoglin single-chain antibody enhances anti-tumor capacity of porcine α1,3GT gene

Tumor could not be completely removed due to the absence of immune storm against tumor. The porcine α1,3 galactosyltransferase (α1,3 GT) induce the hyperacute rejection by synthesizing Galα1-3Galβ1-(3)4GlcNAc-R (αGal) on the surface of graft endothelial cells (ECs) during xeno-transplantation. This study aimed to develop anti-endoglin single-chain Fv fragments (ENG-scFv) conjugated PEGylated immunoliposomes (iLPs) to induce immune storm against tumor. Immune fluorescence was performed to detect the binding of ENG-scFv to human ENG, the endosomal/lysosomal escape of ENG-scFv-iLPs/α1,3 GT, and αGal expression in hENG-HEK293 cells. In vitro MTT assay was performed to measure ENG-scFv-iLPs/α1,3 GT cytotoxicity. NOD/SCID mouse born A549 tumor model was used to evaluate the therapeutic potency of ENG-scFv-iLPs/α1,3 GT. ENG-scFv-iLPs enabled efficient targeting delivery of α1,3 GT plasmid to ENG + tumors neovascular endothelial cells (TnECs), promoted endosomal/lysosomal escape due to the pH-sensitive ability, then synthesized carbohydrate epitope αGal on the surface of these cells to achieve the purpose of destroying the tumor. The mechanism of uptake for nanoparticles was energy driven, the clathrin-mediated endocytosis was the main endocytic pathway of the ENG-mAb-iLPs/α1,3 GT and lipid-raft-mediated of the ENG-scFv-iLPs/α1,3 GT, and macropinocytosis was also involved in intracellular entry. The inhibition of tumor angiogenesis and proliferation by ENG-scFv-iLPs/α1,3 GT was closely related to down-regulation of VEGF. Our findings establish an alternative therapeutic paradigm for scFv-conjugated nanoparticles to induce tumor cell apoptosis and inhibit tumor growth early. Such iLPs nanocarrier could efficiently release α1,3 GT to their distinct sites of action, where the endoglin + tumor neovascular endothelial cells (ENG + TnECs) exist, in a site-specific manner. Therefore, we believe that these scFv-targeted core-shell immunocomplexes are an important potential α1,3 GT delivery system for various solid tumor-targeted therapy.

Non-viral nanocarriers for intracellular delivery of microRNA therapeutics

MicroRNAs are small regulatory noncoding RNAs that regulate various biological processes. Herein, we will present the development of the strategies for intracellular miRNAs delivery, and specially focus on the rational designed routes, their mechanisms of action, as well as potential therapeutics used in the host cells orin vivostudies.

Non-Viral Vectors for Gene Delivery

Introduction:

Gene therapy has emerged out as a promising therapeutic pave for the treatment of genetic and acquired diseases. Gene transfection into target cells using naked DNA is a simple and safe approach which has been further improved by combining vectors or gene carriers. Both viral and non-viral approaches have achieved a milestone to establish this technique, but non-viral approaches have attained a significant attention because of their favourable properties like less immunotoxicity and biosafety, easy to produce with versatile surface modifications, etc. Literature is rich in evidences which revealed that undoubtedly, non–viral vectors have acquired a unique place in gene therapy but still there are number of challenges which are to be overcome to increase their effectiveness and prove them ideal gene vectors.

Conclusion:

To date, tissue specific expression, long lasting gene expression system, enhanced gene transfection efficiency has been achieved with improvement in delivery methods using non-viral vectors. This review mainly summarizes the various physical and chemical methods for gene transfer in vitro and in vivo.

Immunoliposomes with Simvastatin as a Potential Therapeutic in Treatment of Breast Cancer Cells Overexpressing HER2-An In Vitro Study

Lipophilic statins are promising candidates for breast cancer treatment. However, anticancer therapy requires much higher doses of statins than can be delivered orally, and such high doses are known to exert more adverse effects. The main objective of our study was to design a targeted, therapeutic liposomal carrier of simvastatin characterised by high stability and specificity towards breast cancer cells. We chose SKBR3, the cell line that showed the highest sensitivity for simvastatin and liposomal simvastatin treatment. Additionally, SKBR3 has a notably high expression level of human epidermal growth factor receptor 2 (HER2), which we used as a target for our immunoliposomes. To do so we attached humanized anti-HER2 antibody to the envelope of liposomes. We tested the stability and selectivity of the proposed formulation along with the toxicity, ability to induce apoptosis and the effect on signalling pathways involving Akt and Erk kinases. The immunoliposomal formulation of simvastatin is characterized by long-term stability, high selectivity towards HER2-overexpressing breast cancer cells, low non-specific cytotoxicity and effective inhibition of the growth of target cells, presumably by inhibition of signalling pathways and induction of apoptosis. Hence, for the first time, we propose the use of immunoliposomes with simvastatin, targeted directly towards breast cancer cells overexpressing HER2. The prepared immunoliposomes may become a proof of concept in developing new anticancer therapy.

Seek and destroy: improving PK/PD profiles of anticancer agents with nanoparticles

INTRODUCTION

The Pharmacokinetics/pharmacodynamics (PK/PD) relationships with cytotoxics are usually based on a steepening concentration-effect relationship; the greater the drug amount, the greater the effect. The Maximum Tolerated Dose paradigm, finding the balance between efficacy, while keeping toxicities at their manageable level, has been the rule of thumb for the last 50-years. Developing nanodrugs is an appealing strategy to help broaden this therapeutic window. The fact that efficacy and toxicity with cytotoxics are intricately linked is primarily due to the complete lack of specificity toward the tumor tissue during their distribution phase. Because nanoparticles are expected to better target tumor tissue while sparing healthy cells, accumulating large amounts of cytotoxics in tumors could be achieved in a safer way. Areas covered: This review aims at presenting how nanodrugs present unique features leading to reconsidering PK/PD relationships of anticancer agents. Expert commentary: The constant interplay between carrier PK, interactions with cancer cells, payload release, payload PK, target expression and target engagement, makes picturing the exact PK/PD relationships of nanodrugs particularly challenging. However, those improved PK/PD relationships now make the once contradictory higher efficacy and lower toxicities requirement an achievable goal in cancer patients.

A review on cationic lipids with different linkers for gene delivery

Cationic lipids have become known as one of the most versatile tools for the delivery of DNA, RNA and many other therapeutic molecules, and are especially attractive because they can be easily designed, synthesized and characterized. Most of cationic lipids share the common structure of cationic head groups and hydrophobic portions with linker bonds between both domains. The linker bond is an important determinant of the chemical stability and biodegradability of cationic lipid, and further governs its transfection efficiency and cytotoxicity. Based on the structures of linker bonds, they can be grouped into many types, such as ether, ester, amide, carbamate, disulfide, urea, acylhydrazone, phosphate, and other unusual types (carnitine, vinyl ether, ketal, glutamic acid, aspartic acid, malonic acid diamide and dihydroxybenzene). This review summarizes some research results concerning the nature (such as the structure and orientation of linker groups) and density (such as the spacing and the number of linker groups) of linker bond for improving the chemical stability, biodegradability, transfection efficiency and cytotoxicity of cationic lipid to overcome the critical barriers of in vitro and in vivo transfection.

Enhancing the Therapeutic Delivery of Oligonucleotides by Chemical Modification and Nanoparticle Encapsulation

Oligonucleotide (ON) drugs, including small interfering RNA (siRNA), microRNA (miRNA) and antisense oligonucleotides, are promising therapeutic agents. However, their low membrane permeability and sensitivity to nucleases present challenges to in vivo delivery. Chemical modifications of the ON offer a potential solution to improve the stability and efficacy of ON drugs. Combined with nanoparticle encapsulation, delivery at the site of action and gene silencing activity of chemically modified ON drugs can be further enhanced. In the present review, several types of ON drugs, selection of chemical modification, and nanoparticle-based delivery systems to deliver these ON drugs are discussed.

Ophthalmic administration of a 10-fold-lower dose of conventional nanoliposome formulations caused levels of intraocular pressure similar to those induced by marketed eye drops

The purpose of this study was to compare the in vivo efficacy of several timolol (TM)-loaded liposomal formulations with current TM antiglaucoma treatment (aqueous 0.5% w/v eye drops). In this study, conventional liposomes (CL) and deformable liposomes, without (DL1) and with ethanol (DL2) were prepared and characterized. In addition, in vitro release and permeation studies, as well as in vivo lowering intraocular pressure (IOP) and biocompatibility studies were performed. It was found that the quali and quantitative lipid bilayer composition played a significant role in modifying the physical properties of vesicles. The deformability study and electronic microscopy images revealed that membrane elasticity of DL1 and DL2 was much higher than CL. However, in vitro permeation results showed that the flux and permeability coefficient were significantly higher in CL compared to DL. The IOP study revealed that TM-loaded CL showed the best pharmacological activity, in comparison to deformable vesicles. Compared to the eye drops, CL formulation could equally reduce the IOP but using a concentration 10-fold lower, whereas the effective time was significantly longer. In addition, the formulations showed no irritant effects after instillation on the ocular surface.

Epigenetic research in multiple sclerosis: progress, challenges, and opportunities

Multiple sclerosis (MS) is a chronic inflammatory and demyelinating disease of the central nervous system. MS likely results from a complex interplay between predisposing causal gene variants (the strongest influence coming from HLA class II locus) and environmental risk factors such as smoking, infectious mononucleosis, and lack of sun exposure/vitamin D. However, little is known about the mechanisms underlying MS development and progression. Moreover, the clinical heterogeneity and variable response to treatment represent additional challenges to a comprehensive understanding and efficient treatment of disease. Epigenetic processes, such as DNA methylation and histone posttranslational modifications, integrate influences from the genes and the environment to regulate gene expression accordingly. Studying epigenetic modifications, which are stable and reversible, may provide an alternative approach to better understand and manage disease. We here aim to review findings from epigenetic studies in MS and further discuss the challenges and clinical opportunities arising from epigenetic research, many of which apply to other diseases with similar complex etiology. A growing body of evidence supports a role of epigenetic processes in the mechanisms underlying immune pathogenesis and nervous system dysfunction in MS. However, disparities between studies shed light on the need to consider possible confounders and methodological limitations for a better interpretation of the data. Nevertheless, translational use of epigenetics might offer new opportunities in epigenetic-based diagnostics and therapeutic tools for a personalized care of MS patients.

Antibody-targeted nanoparticles for cancer treatment

Nanoparticles (NPs) are diverse and versatile with physical properties that can be employed for use in cancer medicine. Targeting NPs using antibodies and antibody fragments could overcome some of the limitations seen with current targeted therapies. This review will discuss the role of antibody-targeted NPs in the treatment of cancer: as delivery vehicles, targeted theranostic agents and in the evolving field of cancer hyperthermia.

Targeted si-RNA with liposomes and exosomes (extracellular vesicles): How to unlock the potential

The concept of RNA interference therapeutics has been initiated 18 years ago, and the main bottleneck for translation of the technology into therapeutic products remains the delivery of functional RNA molecules into the cell cytoplasm. In the present review article after an introduction about the theoretical basis of RNAi therapy and the main challenges encountered for its realization, an overview of the different types of delivery systems or carriers, used as potential systems to overcome RNAi delivery issues, will be provided. Characteristic examples or results obtained with the most promising systems will be discussed. Focus will be given mostly on the applications of liposomes or other types of lipid carriers, such as exosomes, towards improved delivery of RNAi to therapeutic targets. Finally the approach of integrating the advantages of these two vesicular systems, liposomes and exosomes, as a potential solution to realize RNAi therapy, will be proposed.

Lipid Nanovectors to Deliver RNA Oligonucleotides in Cancer

The growing knowledge on the mechanisms of gene silencing and gene regulation by non-coding RNAs (ncRNA), mainly small interfering RNA (siRNA) and microRNA (miRNA), is providing a significant boost to the development of new therapeutic strategies for the treatment of cancer. However, the design of RNA-based therapeutics is hampered by biopharmaceutical issues, thus requiring the use of suitable delivery strategies. In this regards, lipid nanovectors have been successfully investigated to deliver RNA in different forms of cancer. Compared to other biomaterials, lipids offer advantages such as biocompatibility, biodegradability, easy production, low cost, limited toxicity and immunogenicity. The possibility to formulate these materials in the form of nanovectors allows overcoming biopharmaceutical issues associated to the therapeutic use of RNA, with the possibility to target tumors. This review takes stock of the main lipid nanovectors proposed to deliver ncRNA. For each considered delivery strategy, the rational design and the most meaningful in vitro and in vivo results are reported and discussed.

The delivery of therapeutic oligonucleotides

The oligonucleotide therapeutics field has seen remarkable progress over the last few years with the approval of the first antisense drug and with promising developments in late stage clinical trials using siRNA or splice switching oligonucleotides. However, effective delivery of oligonucleotides to their intracellular sites of action remains a major issue. This review will describe the biological basis of oligonucleotide delivery including the nature of various tissue barriers and the mechanisms of cellular uptake and intracellular trafficking of oligonucleotides. It will then examine a variety of current approaches for enhancing the delivery of oligonucleotides. This includes molecular scale targeted ligand-oligonucleotide conjugates, lipid- and polymer-based nanoparticles, antibody conjugates and small molecules that improve oligonucleotide delivery. The merits and liabilities of these approaches will be discussed in the context of the underlying basic biology.

pH-Responsive Hyaluronic Acid-Based Mixed Micelles for the Hepatoma-Targeting Delivery of Doxorubicin

The tumor targetability and stimulus responsivity of drug delivery systems are crucial in cancer diagnosis and treatment. In this study, hepatoma-targeting mixed micelles composed of a hyaluronic acid-glycyrrhetinic acid conjugate and a hyaluronic acid-l-histidine conjugate (HA-GA/HA-His) were prepared through ultrasonic dispersion. The formation and characterization of the mixed micelles were confirmed via ¹H-NMR, particle size, and ζ potential measurements. The in vitro cellular uptake of the micelles was evaluated using human liver carcinoma (HepG2) cells. The antitumor effect of doxorubicin (DOX)-loaded micelles was investigated in vitro and in vivo. Results indicated that the DOX-loaded HA-GA/HA-His micelles showed a pH-dependent controlled release and were remarkably absorbed by HepG2 cells. Compared with free DOX, the DOX-loaded HA-GA/HA-His micelles showed a higher cytotoxicity to HepG2 cells. Moreover, the micelles effectively inhibited tumor growth in H22 cell-bearing mice. These results suggest that the HA-GA/HA-His mixed micelles are a good candidate for drug delivery in the prevention and treatment of hepatocarcinoma.