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Transforming growth factor-β1 (TGF-β1) promotes the growth and metastasis of lung cancer cells. Therefore, TGF-β1 siRNA (siTGF-β1) gene therapy was introduced to inhibit the expression of TGF-β1 at the nucleic acid level to avert tumor growth and metastasis. However, the delivery of naked siRNA is typically restricted by a short half-life in vivo, difficulties in delivery in vivo, and safety issues. Using siTGF-β1 as a model drug, we established an actively targeted immunoliposome delivery system to investigate the role of siTGF-β1 in non-small-cell lung cancer (NSCLC). The results showed that the constructed immune liposomes were in a position to deliver siTGF-β1 to tumor cells, thus achieving a series of effects such as improving the poor stability and short half-life of naked siRNA. RNA interference of siTGF-β1 reduced the cell viability, growth, and migration potential of human non-small cell lung cancer cells (A549). Moreover, in an A549 tumor-bearing nude mouse model, siTGF-β1 transfection markedly reduced tumor growth and tumor volume. Inhibiting TGF-β1 diminished cancer cell viability and migration and promoted apoptosis in NSCLC, as confirmed by the findings of this study. Therefore, targeting siTGF-β1 with immunoliposomes may be a new therapeutic strategy for treating non-small-cell lung cancer. [ABSTRACT FROM AUTHOR]

AbstractArsenic trioxide (ATO), the active ingredient in Chinese arsenic, effectively inhibits hepatocellular carcinoma (HCC) cell growth, but its clinical application is limited by the lack of a targeted delivery system. Phosphatidylinositol proteoglycan 3 (GPC3) is specifically expressed in HCC, and CPP44 is a cell-penetrating peptide that targets HCC cells. Here, we developed a liposome incorporating ATO with dual surface modifications of anti-GPC3 antibody and CPP44. The system was firstly enriched and localised at the liver tumour site through passive targeting by EPR and active targeting by specific binding of anti-GPC3 antibody to GPC3 protein. CPP44 then facilitated ATO penetration into HCC cells. Specifically, we first employed computational modelling to demonstrate that the covalently-coupled antibody maintained its binding ability to the GPC3 antigen. Subsequent experimental assays revealed that Dl-ATO-Lp exhibited higher cell uptake rate and stronger tumour cell killing effect. In an HCC mouse model, Dl-ATO-Lp achieved effective tumour targeting, with a tumour inhibition rate of 63.43%. This dual-ligand liposome system enhances the targeted delivery and therapeutic efficacy of ATO, offering a promising direction for solid tumour therapy and advancing the clinical application of ATO. [ABSTRACT FROM AUTHOR]

Background: Non-small cell lung cancer (NSCLC) is a leading cause of cancer deaths globally. The most extensive treatment is Tyrosine Kinase Inhibitors (TKIs) that target epidermal growth factor receptor (EGFR) overexpression. Osimertinib, a third-generation TKI is approved to target EGFR exon 19 deletions or exon 21 L858R mutations. However, resistance is inevitable due to emergence of triple mutations (sensitizing mutations, T790M and C797S). To overcome this challenge, a combinatorial approach was used wherein Osimertinib liposomes were conjugated with cetuximab (CTX), an anti-EGFR monoclonal antibody, to improve drug efficacy and delivery. Additionally, pulmonary administration was employed to minimize systemic toxicity and achieve high lung concentrations. Methods: Osimertinib liposomes (OB-LPs) were prepared using thin film hydration method and immunoliposomes (CTX-OB-LPs) were prepared by conjugating the OB-LPs surface with CTX. Liposomes were characterized for particle size, zeta-potential, drug loading, antibody conjugation efficiency, in vitro drug release, and aerosolization performance. Further, the in vitro efficacy of immunoliposomes was evaluated in H1975 cell line. Results: Immunoliposomes exhibited a particle size of 150 nm, high antibody conjugation efficiency (87%), efficient drug release, and excellent aerosolization properties with an aerodynamic diameter of 3 μm and fine particle fraction of 88%. Furthermore, in vitro studies in H1975 cells showed enhanced cytotoxicity with CTX-OB-LPs displaying 1.7-fold reduction and 1.2-fold reduction in IC50 compared to Osimertinib and OB-LPs, respectively. The CTX-OB-LPs also significantly reduced tumor cell migration and colonization compared to Osimertinib and OB-LPs. Conclusions: These successful results for EGFR-targeting inhalable immunoliposomes exhibited potential for contributing to greater anti-tumor efficacy for the treatment of non-small cell lung cancer. [ABSTRACT FROM AUTHOR]

Afatinib (AT), an FDA-approved aniline-quinazoline derivative, is a first-line treatment for metastatic non-small cell lung cancer (NSCLC). Combining it with cetuximab (CX), a chimeric human-murine derivative immunoglobulin-G1 monoclonal antibody (mAb) targeting the extracellular domain of epidermal growth factor receptor (EGFR), has shown significant improvements in median progression-free survival. Previously, we developed cetuximab-conjugated immunoliposomes loaded with afatinib (AT-MLP) and demonstrated their efficacy against NSCLC cells (A549 and H1975). In this study, we aimed to explore the potential of pulmonary delivery to mitigate adverse effects associated with oral administration and intravenous injection. We formulated AT-MLP dry powders (AT-MLP-DPI) via freeze drying using tert-butanol and mannitol as cryoprotectants in the hydration medium. The physicochemical and aerodynamic properties of dry powders were well analyzed firstly. In vitro cellular uptake and cytotoxicity study revealed concentration- and time-dependent cellular uptake behavior and antitumor efficacy of AT-MLP-DPI, while Transwell assay demonstrated the superior inhibitory effects on NSCLC cell invasion and migration. Furthermore, in vivo pharmacokinetic study showed that pulmonary delivery of AT-MLP-DPI significantly increased bioavailability, prolonged blood circulation time, and exhibited higher lung concentrations compared to alternative administration routes and formulations. The in vivo antitumor efficacy study carried on tumor-bearing nude mice indicated that inhaled AT-MLP-DPI effectively suppressed lung tumor growth. Graphical abstract was created with BioRender software (https://biorender.com/) [ABSTRACT FROM AUTHOR]

Although natural products are essential sources of small‐molecule antitumor drugs, some can exert substantial toxicities, limiting their clinical utility. Anthraquinone‐fused enediyne natural products are remarkably potent antitumor drug candidates, and uncialamycin and tiancimycin (TNM) A are under development as antibody‐drug conjugates. Herein, a novel drug delivery system is introduced for TNM A using anti‐human epidermal growth factor receptor 2 (HER2) immunoliposomes (ILs). Trastuzumab‐coated TNM A‐loaded ILs (HER2‐TNM A‐ILs) is engineered with an average particle size of 182.8 ± 2.1 nm and a zeta potential of 1.75 ± 0.12 mV. Compared with liposomes lacking trastuzumab, HER2‐TNM A‐ILs exhibited selective toxicity against HER2‐positive KPL‐4 and SKBR3 cells. Coumarin‐6, a fluorescent TNM A surrogate, is encapsulated within anti‐HER2 ILs; the resultant ILs have enhanced cellular uptake in KPL‐4 and SKBR3 cells when compared with control liposomes. Furthermore, ILs loaded with more Cy5.5 accumulated in KPL‐4 mouse tumors. A single HER2‐TNM A‐IL dose (0.02 mg kg−1) suppressed the growth of HER2‐positive KPL‐4 mouse tumors without apparent toxicity. This study not only provides a straightforward method for the effective delivery of TNM A against HER2‐positive breast tumors but also underscores the potential of IL‐based drug delivery systems when employing highly potent cytotoxins as payloads. [ABSTRACT FROM AUTHOR]

According to the World Health Organization, as of January 3, 2020 to September 13, 2023, there were approximately 23 million confirmed cases of COVID-19 reported in the Russian Federation, about 400 thousand of which were fatal. Considering the high rate of mutation of the RNA-containing virus genome, which inevitably leads to the emergence of new infectious strains (Eris and Pyrola), the search for medicinal antiviral agents remains an urgent task. Moreover, taking into account the actively mutating receptor-binding domain, this task requires fundamentally new solutions. This study proposes a candidate immunoliposomal drug that targets the S protein of SARS-CoV-2 by the monoclonal neutralizing antibody P4A1 and ensures the penetration of a highly active ribonuclease into the virus-infected cell, which degrades, among cellular RNA, viral RNA too. We demonstrate a more than 40-fold increase in the neutralizing activity of the developed drug compared to the free monoclonal neutralizing antibody. [ABSTRACT FROM AUTHOR]

Combining standard surgical procedures with personalized chemotherapy and the continuous monitoring of cancer progression is necessary for effective NSCLC treatment. In this study, we developed liposomal nanoparticles as theranostic agents capable of simultaneous therapy for and imaging of target cancer cells. Copper-64 (64Cu), with a clinically practical half-life (t1/2 = 12.7 h) and decay properties, was selected as the radioisotope for molecular PET imaging. An anti-epidermal growth factor receptor (anti-EGFR) antibody was used to achieve target-specific delivery. Simultaneously, the chemotherapeutic agent doxorubicin (Dox) was encapsulated within the liposomes using a pH-gradient method. The conjugates of 64Cu-labeled and anti-EGFR antibody-conjugated micelles were inserted into the doxorubicin-encapsulating liposomes via a post-insertion procedure (64Cu-Dox-immunoliposomes). We evaluated the size and zeta-potential of the liposomes and analyzed target-specific cell binding and cytotoxicity in EGFR-positive cell lines. Then, we analyzed the specific therapeutic effect and PET imaging of the 64Cu-Dox-immunoliposomes with the A549 xenograft mouse model. In vivo therapeutic experiments on the mouse models demonstrated that the doxorubicin-containing 64Cu-immunoliposomes effectively inhibited tumor growth. Moreover, the 64Cu-immunoliposomes provided superior in vivo PET images of the tumors compared to the untargeted liposomes. We suggest that nanoparticles will be the potential platform for cancer treatment as a widely applicable theranostic system. [ABSTRACT FROM AUTHOR]

The global COVID-19 pandemic arising from SARS-CoV-2 has impacted many lives, gaining interest worldwide ever since it was first identified in December 2019. Till 2023, 752 million cumulative cases and 6.8 million deaths were documented globally. COVID-19 has been rapidly evolving, affecting virus transmissibility and properties and contributing to increased disease severity. The Omicron is the most circulating variant of concern. Although success in its treatment has indicated progress in tackling the virus, limitations in delivering the current antiviral agents in battling emerging variants remain remarkable. With the latest advancements in nanotechnology for controlling infectious diseases, liposomes have the potential to counteract SARS-CoV-2 because of their ability to employ different targeting strategies, incorporating monoclonal antibodies for the active and passive targeting of infected patients. This review will present a concise summary of the possible strategies for utilizing immunoliposomes to improve current treatment against the occurrence of SARSCoV-2 and its variants. [ABSTRACT FROM AUTHOR]

Cathepsin D is an aspartic protease and one of the most abundant proteases. It is overexpressed in many cancers and plays an important role in tumor development, progression, and metastasis. While it is a physiologically intracellular protein, cathepsin D is secreted into the extracellular matrix under pathological conditions, making it an appealing target for drug delivery systems. Here, we present the development and evaluation of a new delivery system for tumor targeting based on immunoliposomes functionalized with pepstatin A—a natural peptide inhibitor of cathepsin D. A lipid tail was added to pepstatin A, enabling its incorporation into the liposomal lipid bilayer. The successful targeting of cathepsin D was confirmed using recombinant cathepsin D and in tumor cell lines, showing the feasibility of this targeting approach and its potential for in vivo use in theragnostic applications. [ABSTRACT FROM AUTHOR]

The Global Technical Strategy for Malaria 2016–2030 aims to achieve a 90% reduction in malaria cases, and strategic planning and execution are crucial for accomplishing this target. This review aims to understand the complex interaction between erythrocytic receptors and parasites and to use this knowledge to actively target the erythrocytic stage of malaria. The review provides insight into the malaria life cycle, which involves various receptors such as glycophorin A, B, C, and D (GPA/B/C/D), complement receptor 1, basigin, semaphorin 7a, Band 3/ GPA, Kx, and heparan sulfate proteoglycan for parasite cellular binding and ingress in the erythrocytic and exo -erythrocytic stages. Synthetic peptides mimicking P. falciparum receptor binding ligands, human serum albumin, chondroitin sulfate, synthetic polymers, and lipids have been utilized as ligands and decorated onto nanocarriers for specific targeting to parasite-infected erythrocytes. The need of the hour for treatment and prophylaxis against malaria is a broadened horizon that includes multiple targeting strategies against the entry, proliferation, and transmission stages of the parasite. Platform technologies with established pre-clinical safety and efficacy should be translated into clinical evaluation and formulation scale-up. Future development should be directed towards nanovaccines as proactive tools against malaria infection. [Display omitted] • The review highlights various receptors utilized by Plasmodium to infect RBCs. • Review showcases GLUT-1, PfEMP1, glycophorin, semaphorin overexpression on pRBCs. • The review explains natural/synthetic polymers, lipids targeting Plasmodium & pRBC. • Includes the in-vitro and in-vivo efficacy of developed targeted nanoformulations. • Promotes development of novel nanoformulations for unexplored pRBC receptors. [ABSTRACT FROM AUTHOR]

Ephrin receptor A2 (EphA2) is a member of the Ephrin/Eph receptor cell-to-cell signaling family of molecules, and it plays a key role in cell proliferation, differentiation, and migration. EphA2 is overexpressed in a broad range of cancers, and its expression is in many cases associated with poor prognosis. We recently developed a novel EphA2-targeting antibody-directed nanotherapeutic encapsulating a labile prodrug of docetaxel (EphA2-ILs-DTXp) for the treatment of EphA2-expressing malignancies. Here, we characterized the expression of EphA2 in bladder cancer using immunohistochemistry in 177 human bladder cancer samples and determined the preclinical efficacy of EphA2-ILs-DTXp in four EphA2-positive patient-derived xenograft (PDX) models of the disease, either as a monotherapy, or in combination with gemcitabine. EphA2 expression was detected in 80-100% of bladder cancer samples and correlated with shorter patient survival. EphA2 was found to be expressed in tumor cells and/or tumor-associated blood vessels in both primary and metastatic lesions with a concordance rate of approximately 90%. The EphA2-targeted antibody-directed nanotherapeutic EphA2-ILs-DTXp controlled tumor growth, mediated greater regression, and was more active than free docetaxel at equitoxic dosing in all four EphA2-positive bladder cancer PDX models. Combination of EphA2-ILs-DTXp and gemcitabine in one PDX model led to improved tumor growth control compared to monotherapies or the combination of free docetaxel and gemcitabine. These data demonstrating the prevalence of EphA2 in bladder cancers and efficacy of EphA2-ILs-DTXp in PDX models support the clinical exploration of EphA2 targeting in bladder cancer.

Introduction. Due to the discovery of antibodies (Ab) targeting molecule with high specificity to the ligand, the "magic bullet" concept has been successfully implemented with various immunoconjugated drugs. Since 1980, Ab conjugates with liposomes, i.e., immunoliposomes (ILs), have been widely investigated to improve the specificity and efficacy of drug therapy. This review is devoted to the characteristic of the basic structural units of ILs on the basis of data analysis of original and review articles on the topic from PubMed, ResearchGate and CyberLeninck databases.Text. ILs are liposomes to which Ab, their fragments or other ligands are usually attached by a special linker. ILs are used to deliver antitumor, cardiovascular, antiviral, antiprotozoal drugs, genetic material, imaging molecules, etc. ILs can be derived from various phospholipids of both natural and synthetic origin, charged or neutral. The most widely used phospholipids in immunoliposomal construction are phosphatidylcholines. To increase the mechanical stability of the bilayer, sterols are introduced into the lipid composition. For selective liposome delivery, targeting ligands must be attached to the nanocarrier via the spacer arm of the PEG. Several types of end-group functionalized lipopolymers are used for this purpose, usually of the general formula X-PEG-LI, where X represents a fragment containing a reactive functional group − maleimide, biotin, cyanur, amine, etc. These lipid PEG-conjugates exhibit excellent amphiphilic properties and offer excellent advantages for the modification, formulation, and delivery of various drugs. The Ab used should enhance the accumulation of the liposomal drug in the target areas with minimal cross-reactivity with healthy tissues. Ready-made drugs based on monoclonal Ab, such as trastuzumab, cetuximab, panitumumumab, bevacizumab; commercial Ab intended for research purposes, and laboratory synthesized Ab and their fragments are used in the preparation of ILs. Ab can be attached to liposomes by two main methods: direct covalent conjugation and postinsertion.Conclusion. The results of this study allowed us to summarize the variety of literature data on the composition of ILs and the possibility of using auxiliary components to achieve the goal in the development of the drug.

Docetaxel (DTX) is a non-selective antineoplastic agent with low solubility and a series of side effects. The technology of pH-sensitive and anti-epidermal growth factor receptor (anti-EGFR) immunoliposomes aims to increase the selective delivery of the drug in the acidic tumor environment to cells with EFGR overexpression. Thus, the study aimed to develop pH-sensitive liposomes based on DOPE (dioleoylphosphatidylethanolamine) and CHEMS (cholesteryl hemisuccinate), using a Box–Behnken factorial design. Furthermore, we aimed to conjugate the monoclonal antibody cetuximab onto liposomal surface, as well as to thoroughly characterize the nanosystems and evaluate them on prostate cancer cells. The liposomes prepared by hydration of the lipid film and optimized by the Box–Behnken factorial design showed a particle size of 107.2 ± 2.9 nm, a PDI of 0.213 ± 0.005, zeta potential of −21.9 ± 1.8 mV and an encapsulation efficiency of 88.65 ± 20.3%. Together, FTIR, DSC and DRX characterization demonstrated that the drug was properly encapsulated, with reduced drug crystallinity. Drug release was higher in acidic pH. The liposome conjugation with the anti-EGFR antibody cetuximab preserved the physicochemical characteristics and was successful. The liposome containing DTX reached an IC50 at a concentration of 65.74 nM in the PC3 cell line and 28.28 nM in the DU145 cell line. Immunoliposome, in turn, for PC3 cells reached an IC50 of 152.1 nM, and for the DU145 cell line, 12.60 nM, a considerable enhancement of cytotoxicity for the EGFR-positive cell line. Finally, the immunoliposome internalization was faster and greater than that of liposome in the DU145 cell line, with a higher EGFR overexpression. Thus, based on these results, it was possible to obtain a formulation with adequate characteristics of nanometric size, a high encapsulation of DTX and liposomes and particularly immunoliposomes containing DTX, which caused, as expected, a reduction in the viability of prostate cells, with high cellular internalization in EGFR overexpressing cells. [ABSTRACT FROM AUTHOR]

Antisense oligonucleotides (ASOs) composed of nucleic acid mimics (NAMs) monomers are considered as potential novel therapeutic drugs against bacterial infections. However, bacterial envelopes are generally impermeable to naked oligonucleotides. Herein, liposomes loaded with NAMs-modified oligonucleotides (LipoNAMs) were evaluated to deliver ASOs in Escherichia coli. Specifically, we tested several surface modifications that included methoxyPEG conjugated to different lipid anchors or modification of the PEG distal ends with maleimide groups and antibodies. MethoxyPEG coated LipoNAMs showed low delivery efficiency for most bacteria, but maleimide-functionalized PEG LipoNAMs were able to deliver ASOs to nearly half of the bacterial population. Conjugation of antibodies to maleimide-functionalized PEG LipoNAMs increased 1.3-fold the delivery efficiency, enhancing the selectivity towards E. coli and biocompatibility. This work demonstrated for the first time that the coupling of antibodies to PEGylated liposomes can significantly improve the delivery of ASOs in E. coli , which might bring alternative routes for the treatment of bacterial infections in the future. [Display omitted] • Delivery of oligonucleotides in E. coli depends on liposomes surface characteristics. • MethoxyPEG coated liposomes are not effective to deliver oligonucleotides in E. coli. • MaleimidePEG coated liposomes enhanced the oligonucleotides delivery in bacteria. • Anti- E. coli antibodies conjugated to PEG strands enhanced the delivery efficiency. • Conjugation of antibodies improves the liposomes'biocompatibility. [ABSTRACT FROM AUTHOR]

Acute thrombosis is a leading cause of mortality and morbidity worldwide. Pharmacological thrombolysis relies on plasminogen activators (PAs), which are associated with major side effects including potentially fatal bleeding. Alternative therapeutic options that do not rely on PAs are urgently required. Here, the efficacy of targeted photothermal therapy is evaluated for thrombolysis using liposomes loaded with IR780 dye, which release heat upon near‐infrared (NIR) irradiation. Liposomes targeted to activated platelets—one of the main components of thrombi—accumulate preferentially in thrombi both in vitro and in vivo compared to non‐targeted controls. In a mouse model of thrombosis, targeted IR780 immunoliposomes (Tar‐IR‐L) produce ≈12 °C average local temperature increase upon NIR irradiation (5 min, 1 W cm−2). This causes a significant reduction in clot area compared to controls treated with non‐targeted liposomes or phosphate‐buffered saline, which only increase local temperature slightly (6 and 3 °C) when irradiated. Co‐loading a low‐dose single chain urokinase plasminogen activator (scuPA) to targeted IR780 liposomes (Tar‐scuPA‐IR‐L) does not result in a superior thrombolytic effect, which indicates that photothermal therapy alone may allow thrombolysis without the need for fibrinolytic drugs. This approach may prevent potential bleeding complications, promising a safer alternative to current pharmacological approaches. [ABSTRACT FROM AUTHOR]

[Display omitted] • Immunoliposomes can actively target Langerhans cells and effectively promote the presentation of antigens. • Immunoliposomes can reach the draining lymph nodes and spleen by microneedle. • Immune response stimulated by immunoliposomes combined with microneedle was Th1-biased. Novel Coronavirus is affecting human's life globally and vaccines are one of the most effective ways to combat the epidemic. Transcutaneous immunization based on microneedle (MN) has attracted much attention because of its painlessness, rapidity, high efficiency and good compliance. In this study, CD11c monoclonal antibody-immunoliposomes (OVA@CD11c-ILP) actively targeting to Langerhans cells (LCs) were successfully prepared and were delivered by the microchannels of skin produced by MN to induce an immune response in vivo. OVA@CD11c-ILP could be targeted to LCs by conjugating CD11c monoclonal antibody to the surface of the ILP. OVA@CD11c-ILP promoted the maturation of dendritic cells (DCs) and the uptake and endocytosis of antigen by LCs. Moreover, OVA@CD11c-ILP immunization can significantly inhibit tumor growth and prolong overall survival. Furthermore, a higher antibody's titer ratio of IgG1/IgG2a indicated that the immune response stimulated by this immunization method was Th1-biased and the liposomes showed Th1-type adjuvant effect. In conclusion, the combination delivery system of immunoliposomes and microneedle can significantly improve the efficiency of antigen presentation and effectively activate cellular immune responses in the body, which is expected to be a promising transdermal immune strategy. [ABSTRACT FROM AUTHOR]

Prostate cancer (PC) is a leading cause of cancer-related deaths in men worldwide. Interleukin-30 (IL-30) is a PC progression driver, and its suppression would be strategic for fighting metastatic disease. Biocompatible lipid nanoparticles (NPs) were loaded with CRISPR-Cas9gRNA to delete the human IL30 (hIL30) gene and functionalized with anti-PSCA-Abs (Cas9hIL30-PSCA NPs). Efficiency of the NPs in targeting IL-30 and the metastatic potential of PC cells was examined in vivo in xenograft models of lung metastasis, and in vitro by using two organ-on-chip (2-OC)-containing 3D spheroids of IL30 + PC-endothelial cell co-cultures in circuit with either lung-mimicking spheroids or bone marrow (BM)-niche-mimicking scaffolds. Cas9hIL30-PSCA NPs demonstrated circulation stability, genome editing efficiency, without off-target effects and organ toxicity. Intravenous injection of three doses/13 days, or five doses/20 days, of NPs in mice bearing circulating PC cells and tumor microemboli substantially hindered lung metastasization. Cas9hIL30-PSCA NPs inhibited PC cell proliferation and expression of IL-30 and metastasis drivers, such as CXCR2, CXCR4, IGF1, L1CAM, METAP2, MMP2, and TNFSF10, whereas CDH1 was upregulated. PC-Lung and PC-BM 2-OCs revealed that Cas9hIL30-PSCA NPs suppressed PC cell release of CXCL2/GROβ, which was associated with intra-metastatic myeloid cell infiltrates, and of DKK1, OPG, and IL-6, which boosted endothelial network formation and cancer cell migration. Development of a patient-tailored nanoplatform for selective CRISPR-mediated IL-30 gene deletion is a clinically valuable tool against PC progression., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background/aim: High-risk/refractory neuro-blastoma (NBL) treatments include anti-GD2-monoclonal antibodies (mAbs). Several immunoliposomes (ILs) covered with anti-GD2-mAbs (GD2-ILs) have been tested pre-clinically. We aimed to review literature on GD2-IL for characteristics of nanoparticles/payloads, conjugation of mAb/fragments and preclinical data, as well as to explore the feasibility of a recently proposed GD2-IL loaded with the antimetabolite oxamate., Materials and Methods: Initial PubMed search was generalized for immunoliposomes in cancer. Further search was focused on papers for GD2-IL [keywords: "Immunoliposomes and cancer (or neuroblastoma)"]., Results: There were 811 results on "immunoliposomes"; >50% were on "immunoliposomes, cancer" (n=439, June 2024). Seventeen items resulted from "immunoliposomes, neuroblastoma" (one was "publishers' correction"). Sixteen GD2-IL references were reviewed (1993-current). The mean±SD GD2-ILs size was 124.8±31 nm (range=86-171). Six papers described GD2-ILs with DNA-damaging agents [doxorubicin (n=4), etoposide (n=1), irinotecan+HDAC inhibitor (n=1)]. Other payloads included: fenretinide (n=4 papers), C-myb antisense (n=2), survivin inhibitor (n=1), tyrosine kinase inhibitor (n=1), IL15 (n=1), and oxamate (n=1). These 9 drug-loads included both hydrophilic and hydrophobic molecules. Except for IL15 and C-myb antisense with high molecular weights (MWs), and oxamate with low MW, the remaining compounds had comparable MWs (496±100 g/mol, range=349-588.6). The overall encapsulation efficiency was 66.2±25.6%. There were 17-30 mAb molecules attached to an IL with PEGylation. Experiments with GD2-positive/GD2-negative cells demonstrated selective efficacy/tropism of GD2-ILs. Mouse models confirmed efficacy, GD2-specific tumor accumulation, decreased toxicity, and improved pharmacokinetic-pharmacodynamics., Conclusion: PEGylated anti-GD2-IL may allow NBL tropism. A size of approximately 100 nm could allow vascular permeability and packaging of oxamate in amounts needed for profound/selective lactate dehydrogenase-A inhibition. Thus, oxamate-loaded GD2-ILs may allow exploring the great translational potential of Warburg effect inhibition in GD2-positive cancers., (Copyright © 2024 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Si306, a pyrazolo[3,4-d]pyrimidine derivative recently identified as promising anticancer agent, has shown favorable in vitro and in vivo activity profile against neuroblastoma (NB) models by acting as a competitive inhibitor of c-Src tyrosine kinase. Nevertheless, Si306 antitumor activity is associated with sub-optimal aqueous solubility, which might hinder its further development. Drug delivery systems were here developed with the aim to overcome this limitation, obtaining suitable formulations for more efficacious in vivo use. Si306 was encapsulated in pegylated stealth liposomes, undecorated or decorated with a monoclonal antibody able to specifically recognize and bind to the disialoganglioside GD2 expressed by NB cells (LP[Si306] and GD2-LP[Si306], respectively). Both liposomes possessed excellent morphological and physio-chemical properties, maintained over a period of two weeks. Compared to LP[Si306], GD2-LP[Si306] showed in vitro specific cellular targeting and increased cytotoxic activity against NB cell lines. After intravenous injection in healthy mice, pharmacokinetic profiles showed increased plasma exposure of Si306 when delivered by both liposomal formulations, compared to that obtained when Si306 was administered as free form. In vivo tumor homing and cytotoxic effectiveness of both liposomal formulations were finally tested in an orthotopic animal model of NB. Si306 tumor uptake resulted significantly higher when encapsulated in GD2-LP, compared to Si306, either free or encapsulated into untargeted LP. This, in turn, led to a significant increase in survival of mice treated with GD2-LP[Si306]. These results demonstrate a promising antitumor efficacy of Si306 encapsulated into GD2-targeted liposomes, supporting further therapeutic developments in pre-clinical trials and in the clinic for NB. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract Fibroblast growth factor receptor 3 (FGFR3) plays an important regulatory role in tumor cell proliferation and drug resistance. FGFR3 is often constitutively active in many tumors. To deliver drugs into tumor cells by targeting FGFR3 will be a promising and potential strategy for cancer therapy. In this study, a novel fusion protein, ScFv-Cys containing a single chain variable fragment (ScFv) and an additional C-terminal cysteine residue, was generated at a rate of 10 mg/L of bacterial culture and purified at 95% by Ni-NTA chromatography. Subsequently, the recombinant ScFv-Cys was coupled with malPEG2000-DSPE and incorporated into liposomes to generate the immunoliposomes. The results indicated that immunoliposomes can specifically deliver the fluorescent molecules, Dio into bladder cancer cells highly expressing FGFR3. In conclusion, we successfully generated FGFR3-specific immunoliposomes, and proved its targeting effect and delivering ability.

The accumulation of extracellular amyloid-beta (Aβ), denoted as senile plaques, and intracellular neurofibrillary tangles (formed by hyperphosphorylated Tau protein) in the brain are two major neuropathological hallmarks of Alzheimer’s disease (AD). The current and most accepted hypothesis proposes that the oligomerization of Aβ peptides triggers the polymerization and accumulation of amyloid, which leads to the senile plaques. Several strategies have been reported to target Aβ oligomerization/polymerization. Since it is thought that Aβ levels in the brain and peripheral blood maintain equilibrium, it has been hypothesized that enhancing peripheral clearance (by shifting this equilibrium towards the blood) might reduce Aβ levels in the brain, known as the sink effect. This process has been reported to be effective, showing a reduction in Aβ burden in the brain as a consequence of the peripheral reduction of Aβ levels. Nanoparticles (NPs) may have difficulty crossing the blood-brain barrier (BBB), initially due to their size. It is not clear whether particles in the range of 50–100 nm should be able to cross the BBB without being specifically modified for it. Despite the size limitation of crossing the BBB, several NP derivatives may be proposed as therapeutic tools. The purpose of this review is to summarize some therapeutic approaches based on nanoliposomes using two complementary examples: First, unilamellar nanoliposomes containing Aβ generic ligands, such as sphingolipids, gangliosides or curcumin, or some sphingolipid bound to the binding domain of ApoE; and second, nanoliposomes containing monoclonal antibodies against Aβ. Following similar rationale NPs of poly(lactide-co-glycolide)-poly (ethylene glycol) conjugated with curcumin-derivate (PLGA-PEG-B6/Cur) were reported to improve the spatial learning and memory capability of APP/PS1 mice, compared with native curcumin treatment. Also, some new nanostructures such as exosomes have been proposed as a putative therapeutic and prevention strategies of AD. Although the unquestionable interest of this issue is beyond the scope of this review article. The potential mechanisms and significance of nanoliposome therapies for AD, which are still are in clinical trials, will be discussed.

Development of a cure for HIV/AIDS has been a great challenge due to the establishment of the HIV-1 viral reservoir, mainly within resting CD4+ memory T cells. As a step towards a cure for HIV, this study aimed to develop an approach that reactivates HIV-1 latently infected cells by employing a drug delivery system using immunoliposomes targeting CD4+ T cells. The immunoliposomes were examined for physicochemical properties and determined for their potential stability. A histone deacetylase (HDAC) inhibitor SAHA was used as a model drug being encapsulated within the immunoliposomes that are conjugated with anti-CD4 antibodies. The immunoliposomes are effectively and specifically taken up by the CD4+ J-Lat 10.6 cells, and significantly less so by the CD4− ACH-2 cells. For HIV-1 latent cell reactivation, SAHA-encapsulated immunoliposomes (SAHA-IL) and SAHA-encapsulated liposomes (SAHA-LP) can reactivate HIV latency as effectively as SAHA compound alone. Additionally, a combination of SAHA-IL and a protein kinase C activator, bryostatin-1, also exhibits a synergistic effect on the reactivation. The developed system thus presents a viable option to become a promising approach for HIV-1 latency reversing treatment, a strategy towards developing a functional cure for HIV. [ABSTRACT FROM AUTHOR]

Si306, a pyrazolo[3,4-d]pyrimidine derivative recently identified as promising anticancer agent, has shown favorable in vitro and in vivo activity profile against neuroblastoma (NB) models by acting as a competitive inhibitor of c-Src tyrosine kinase. Nevertheless, Si306 antitumor activity is associated with sub-optimal aqueous solubility, which might hinder its further development. Drug delivery systems were here developed with the aim to overcome this limitation, obtaining suitable formulations for more efficacious in vivo use. Si306 was encapsulated in pegylated stealth liposomes, undecorated or decorated with a monoclonal antibody able to specifically recognize and bind to the disialoganglioside GD2 expressed by NB cells (LP[Si306] and GD2-LP[Si306], respectively). Both liposomes possessed excellent morphological and physio-chemical properties, maintained over a period of two weeks. Compared to LP[Si306], GD2-LP[Si306] showed in vitro specific cellular targeting and increased cytotoxic activity against NB cell lines. After intravenous injection in healthy mice, pharmacokinetic profiles showed increased plasma exposure of Si306 when delivered by both liposomal formulations, compared to that obtained when Si306 was administered as free form. In vivo tumor homing and cytotoxic effectiveness of both liposomal formulations were finally tested in an orthotopic animal model of NB. Si306 tumor uptake resulted significantly higher when encapsulated in GD2-LP, compared to Si306, either free or encapsulated into untargeted LP. This, in turn, led to a significant increase in survival of mice treated with GD2-LP[Si306]. These results demonstrate a promising antitumor efficacy of Si306 encapsulated into GD2-targeted liposomes, supporting further therapeutic developments in pre-clinical trials and in the clinic for NB.

Cancer immunotherapy, a promising and widely applied mode of oncotherapy, makes use of immune stimulants and modulators to overcome the immune dysregulation present in cancer, and leverage the host’s immune capacity to eliminate tumors. Although some success has been seen in this field, toxicity and weak immune induction remain challenges. Liposomal nanosystems, previously used as targeting agents, are increasingly functioning as immunotherapeutic vehicles, with potential for delivery of contents, immune induction, and synergistic drug packaging. These systems are tailorable, multifunctional, and smart. Liposomes may deliver various immune reagents including cytokines, specific T-cell receptors, antibody fragments, and immune checkpoint inhibitors, and also present a promising platform upon which personalized medicine approaches can be built, especially with preclinical and clinical potentials of liposomes often being frustrated by inter- and intrapatient variation. In this review, we show the potential of liposomes in cancer immunotherapy, as well as the methods for synthesis and in vivo progression thereof. Both preclinical and clinical studies are included to comprehensively illuminate prospects and challenges for future research and application.

Graphical abstract Abstract Afatinib, a selective and irreversible inhibitor of tyrosine kinase, was approved for the treatment of advanced non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) overexpression in 2013. Cetuximab (CTX), an anti-EGFR monoclonal antibody, is co-administered with afatinib to improve efficacy. Unfortunately, dose-related adverse reactions caused by combination therapy have affected patient compliance, and have resulted in treatment discontinuation in severe cases. In the present study, afatinib was encapsulated in "liposomes" (LPs) to achieve longer circulation in the blood and an enhanced permeability-and-retention effect in tumors. Concomitantly, CTX was designed to bind to drug-loaded LPs to form "immuno-LPs" for tumor-cell selectivity and therapeutic activity. In vitro , the cellular internalization rate of immuno-LPs was significantly higher than that of LPs (p < 0.05). In vivo , a markedly increased area under the curve and prolonged terminal half-life were detected in rats injected with the two LP formulations, indicating that LP encapsulation protected afatinib from binding to hemoglobin to control the risk of idiosyncratic drug reactions. Compared with free afatinib and LPs, immuno-LPs exhibited strongly enhanced drug delivery and antitumor efficacy in an NSCLC xenograft model, with stronger tumor selectivity and potentially fewer side-effects. Hence, EGFR-targeting immuno-LPs appear to be promising for NSCLC treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] Active targeting nano-delivery is a promising approach to enhance therapeutic efficacy and specificity to the target cells. Liposomes (LPs) have been widely studied for the active targeting delivery due to their low toxicity, biodegradability, biocompatibility, and feasibility of surface medication to provide the interactions with cell receptors. One of the strategies is to functionalize the surface of LPs with monoclonal antibodies (mAbs) to obtain immunoliposomes (imLPs) that recognize specific receptors on target cells. Among several target cells, CD4+ T cells are known for playing a pivotal role in controlling the immune system in several diseases, including cancers, inflammatory diseases, and viral infections, particularly HIV-1. Here, we demonstrate two methods for conjugating αCD4 mAb with imLPs for specific targeting of CD4+ T cells that can harbor viral genome and serve as a predominant latent HIV reservoir. LPs conjugated with αCD4 mAb via neutravidin-biotin linkage were used for selectively targeting CD4+ J-Lat 10.6 cells. We demonstrate, via flow cytometry, the importance of the conjugation step, mAb density, and the presence of polyethylene glycol (PEG) for effective drug delivery to CD4+ T cells. The cellular uptake of imLPs is substantially higher if the imLPs are functionalized with the pre-conjugated αCD4 mAb-neutravidin complex. Furthermore, imLPs loaded with HIV-1 latency reversing agent, suberoylanilide hydroxamic acid (SAHA), could reactivate the J-Lat 10.6 cells, suggesting that the αCD4-imLPs could be potentially used as a targeted drug delivery system for HIV-1 latency reactivation or other CD4-targeted immunotherapies. [ABSTRACT FROM AUTHOR]

Prostate cancer (PCa) is the second most common cancer in men worldwide and the fifth leading cause of death by cancer. The overexpression of TCTP protein plays an important role in castration resistance. Over the last decade, antisense technology has emerged as a rising strategy in oncology. Using antisense oligonucleotide (ASO) to silence TCTP protein is a promising therapeutic option—however, the pharmacokinetics of ASO does not always meet the requirements of proper delivery to the tumor site. In this context, developing drug delivery systems is an attractive strategy for improving the efficacy of ASO directed against TCTP. The liposome should protect and deliver ASO at the intracellular level in order to be effective. In addition, because prostate cancer cells express Her2, using an anti-Her2 targeting antibody will increase the affinity of the liposome for the cell and optimize the intratumoral penetration of the ASO, thus improving efficacy. Here, we have designed and developed pegylated liposomes and Her2-targeting immunoliposomes. Mean diameter was below 200 nm, thus ensuring proper enhanced permeation and retention (EPR) effect. Encapsulation rate for ASO was about 40%. Using human PC-3 prostate cancer cells as a canonical model, free ASO and ASO encapsulated into either liposomes or anti-Her2 immunoliposomes were tested for efficacy in vitro using 2D and 3D spheroid models. While the encapsulated forms of ASO were always more effective than free ASO, we observed differences in efficacy of encapsulated ASO. For short exposure times (i.e., 4 h) ASO liposomes (ASO-Li) were more effective than ASO-immunoliposomes (ASO-iLi). Conversely, for longer exposure times, ASO-iLi performed better than ASO-Li. This pilot study demonstrates that it is possible to encapsulate ASO into liposomes and to yield antiproliferative efficacy against PCa. Importantly, despite mild Her2 expression in this PC-3 model, using a surface mAb as targeting agent provides further efficacy, especially when exposure is longer. Overall, the development of third-generation ASO-iLi should help to take advantage of the expression of Her2 by prostate cancer cells in order to allow greater specificity of action in vivo and thus a gain in efficacy.

Ephrin receptor A2 (EphA2) is a member of the Ephrin/Eph receptor cell-to-cell signaling family of molecules, and it plays a key role in cell proliferation, differentiation, and migration. EphA2 is overexpressed in a broad range of cancers, and its expression is in many cases associated with poor prognosis. We recently developed a novel EphA2-targeting antibody-directed nanotherapeutic encapsulating a labile prodrug of docetaxel (EphA2-ILs-DTXp) for the treatment of EphA2-expressing malignancies. Here, we characterized the expression of EphA2 in bladder cancer using immunohistochemistry in 177 human bladder cancer samples and determined the preclinical efficacy of EphA2-ILs-DTXp in four EphA2-positive patient-derived xenograft (PDX) models of the disease, either as a monotherapy, or in combination with gemcitabine. EphA2 expression was detected in 80–100% of bladder cancer samples and correlated with shorter patient survival. EphA2 was found to be expressed in tumor cells and/or tumor-associated blood vessels in both primary and metastatic lesions with a concordance rate of approximately 90%. The EphA2-targeted antibody-directed nanotherapeutic EphA2-ILs-DTXp controlled tumor growth, mediated greater regression, and was more active than free docetaxel at equitoxic dosing in all four EphA2-positive bladder cancer PDX models. Combination of EphA2-ILs-DTXp and gemcitabine in one PDX model led to improved tumor growth control compared to monotherapies or the combination of free docetaxel and gemcitabine. These data demonstrating the prevalence of EphA2 in bladder cancers and efficacy of EphA2-ILs-DTXp in PDX models support the clinical exploration of EphA2 targeting in bladder cancer.

Antibody-targeted lipid nanoparticles (Ab-LNPs) are rapidly gaining traction as multifaceted platforms in precision medicine, adept at delivering a diverse array of therapeutic agents, including nucleic acids and small molecules. This review provides an incisive overview of the latest developments in the field of Ab-LNP technology, with a special emphasis on pivotal design aspects such as antibody engineering, bioconjugation strategies, and advanced formulation techniques. Furthermore, it addresses critical chemistry, manufacturing, and controls (CMC) considerations and thoroughly examines the in vivo dynamics of Ab-LNPs, underscoring their promising potential for clinical application. By seamlessly blending scientific advancements with practical industrial perspectives, this review casts a spotlight on the burgeoning role of Ab-LNPs as an innovative and potent tool in the realm of targeted drug delivery.

Graphical abstract Abstract Purpose Conventional chemotherapy is associated with therapy-limiting side effects, which might be alleviated by targeted chemotherapeutics such as immunoliposomes. The targeting ligands of immunoliposomes are commonly attached by unspecific chemical conjugation, bearing risk of structural heterogeneity and therewith related biological consequences. Chemoenzymatic methods may mitigate such risks through site-specific conjugation. Methods The formulation parameters for pentaglycine–modified, doxorubicin–loaded liposomes and the reaction conditions for a site–specific, Sortase–A mediated conjugation with monoclonal antibodies were thoroughly evaluated. The cytotoxicity of such sortagged, epidermal growth factor receptor (EGFR)-specific immunoliposomes was tested on human breast cancer cells. Results Sortaggable liposomes with a defined size (140 nm, PDI < 0.25) and high encapsulation efficiency (>90%) were obtained after manufacturing optimization. A ratio of 1.0–2.5 µM mAb/100 µM pentaglycine yielded stable dispersions and circumvented carrier precipitation during ligand grafting. The cytotoxicity on EGFR+ MDA–MB–468 was up to threefold higher for EGFR–specific immunoliposomes than for the nontargeted controls. Conclusions Sortase–A is suitable to generate immunoliposomes with a site–specific ligand–carrier linkage and hence improves chemical homogeneity of targeted therapeutics. However, the sweet spot for manufacturability utilizing mAbs with two Sortase–A recognition sites is narrow, making mono-reactive binders such as scFvs or Fab's preferable for a further development. Despite this, the immunoliposomes demonstrated a targeted delivery of doxorubicin, indicating the potential to increase the therapeutic window during the treatment of EGFR+ tumors. [ABSTRACT FROM AUTHOR]

Aim: USP22, a member of ubiquitin-specific proteases (USPs), is a well-defined protein that promotes poor prognosis, invasion and metastasis, and also participates in the maintenance of cancer stem cells. USP22 siRNA-loaded nanoliposomes conjugated with CD44 antibodies (USP22-NLs-CD44) were constructed to enhance the therapeutic effect of USP22 siRNA against gastric cancer stem cells.Materials& Methods: The targeting and therapeutic efficacies of USP22-NLs-CD44 against gastric cancer stem cells were evaluated.Results& Conclusion: USP22-NLs-CD44 was demonstrated to be able to effectively deliver USP22 siRNA to CD44+ gastric cancer stem cells, achieving superior therapeutic effects against CD44+ gastric cancer stem cells than nontargeted nanoliposomes. USP22-NLs-CD44 may provide a novel approach to eradicate gastric cancer stem cells in the near future. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The therapeutic index of drugs can be increased via drug encapsulation in actively targeted, meaning ligand modified drug delivery systems. The manufacturing of such targeted drug delivery systems, in particular the conjugation between drug carrier and ligand, can be done by enzymatic conjugation methods, exploiting the site-specific, bioorthogonal nature of these reactions. The use of such enzymes like Sortase-A transpeptidase requires efficient purification methods, as residuals of the enzyme may be responsible for immunogenic potential and drug product instabilities. These instabilities may be based on the enzymatic reverse reaction, meaning here a cleavage between ligand and drug carrier. In the presented work, two differently PEGylated formulations were modified with variable fragments of camelid heavy chain-only antibodies (VHH) via Sortase-A, purified by different methodologies and tested for ligand cleavage upon storage. Strongly PEGylated liposomes (PEGhigh-LS) were found to retain higher amounts of Sortase-A than lowly PEGylated ones (PEGlow-LS) after dialysis purification. Surprisingly, this did not correlate with ligand stability during storage. PEGhigh-LS were less prone for degradation, compared to PEGlow-LS, which showed a ligand cleavage of 20% after an 8 weeks storage at 2–8 °C. Nonetheless, overall degradation could be minimized by an additional affinity bead purification procedure. Liposomes modified with a CD11b-specific VHH were tested for their in vitro and in vivo targeting ability towards CD11b+ cells. Specific targeting of CD11b was achieved in vitro and in vivo on various cell types. PEGylation decreased the targeting effect in vitro, however no differences between PEGhigh or PEGlow formulations were observed in vivo. The obtained results underline the need for a thorough characterization of novel conjugation strategies as well as an early in vivo characterization of such targeted drug delivery systems. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Active targeting with ligand coated liposomal drug delivery systems is a means to increase the therapeutic index of drugs. Stable ligand coating requires bilayer anchorage of the commonly proteinaceous ligands and hence a conjugation of lipid structures towards amino acids. This often leads to heterogeneous reaction products especially when chemical coupling methods are employed. Chemoenzymatic Sortase-A mediated transpeptidation (sortagging) is a useful tool to avoid this protein heterogeneity through its site-specific, bioorthogonal ligation mechanism. Manufacturing of such sortaggable, pentaglycine modified liposomes was developed by adaption of a scalable solvent injection technique. The pentaglycine liposomes were prepared with different degrees of PEGylation and steric accessibility of the pentaglycine motif. Comparable hydrodynamic diameters (146–188 nm) of the different formulations were obtained after a flow rate screening. The sortagging reactivity of a single-domain antibody (VHH) towards the pentaglycine liposomes was strongly dependent on the steric accessibility of the pentaglycine nucleophile. Adjusting the pentaglycine to ligand ratio improved conversion rates up to 80%. The liposome bound VHH was accessible for its soluble antigen as shown by a chromatography-based binding assay. Mono- and granulocytes could be selectively targeted in vitro by conjugation of BMX1, a VHH directed towards human myeloid cell surface marker CD11b. Confocal microscopy revealed intracellular localization of the targeted liposomes. The developability of those pentaglycine liposomes as well as their proof of principle for targeted drug delivery shows their potential for further investigation, for example as delivery platform for diagnostics or drugs into the tumor microenvironment. [ABSTRACT FROM AUTHOR]

Purpose: Gastric cancer, the cancer initiated from the stomach, is ranked as the third most frequent reason of cancer death worldwide. Gastric cancer-initiating cells (CICs) are one of the crucial causes for the metastasis and recurrence of gastric cancer, and CD44 is considered to be one marker for gastric CICs. Special AT-rich sequence binding protein 1 (SATB1) is a protein that promotes cancer progression, metastasis, and invasion and also participates in the maintenance of CICs. In this study, we investigated the therapeutic effect of SATB1 siRNA against gastric CICs and we constructed SATB1 siRNA-encapsulated immunoliposomes conjugated with CD44 antibodies (CD44-SATB1-ILs) to enhance the therapeutic effect of SATB1 siRNA against gastric CICs. Methods: We investigated the therapeutic effect of the SATB1 suppression by SATB1 siRNA on CD44+ gastric CICs. CD44-SATB1-ILs were developed by the lyophilization/hydration approach. The targeting and cytotoxic effect of CD44-SATB1-ILs toward gastric CICs were evaluated in vitro. Results: In this study, for the first time, we confirmed that SATB1 suppression by SATB1 siRNA preferentially eliminated CD44+ gastric CICs. The results showed that CD44-SATB1-ILs could efficiently and specifically promote the SATB1 siRNA delivery to CD44+ gastric CICs, achieving superior therapeutic effects against CD44+ gastric CICs than non-targeted liposomes. Conclusion: As far as we know, our report is the first research that indicated the promotion of siRNA delivery via nanoparticles to gastric CICs and achievement of superior therapeutic effect against gastric CICs by utilization of CD44 antibody. Therefore, CD44-SATB1-ILs represent an up-and-coming approach for eliminating gastric CICs and also a promising treatment for therapy of gastric cancer. [ABSTRACT FROM AUTHOR]

Activated endothelial cells play a pivotal role in the pathology of inflammatory disorders and thus present a target for therapeutic intervention by drugs that intervene in inflammatory signaling cascades, such as rapamycin (mammalian target of rapamycin (mTOR) inhibitor). In this study we developed anti-E-selectin immunoliposomes for targeted delivery to E-selectin over-expressing tumor necrosis factor-α (TNF-α) activated endothelial cells. Liposomes composed of 1,2-dipalmitoyl- sn - glycero -3.;hosphocholine (DPPC), Cholesterol, and 1,2-Distearoyl- sn - glycero -3-phosphoethanolamine-N-[methoxy(polyethyleneglycol)-2000]-maleimide (DSPE-PEG-Mal) were loaded with rapamycin via lipid film hydration, after which they were further functionalized by coupling N-succinimidyl-S-acetylthioacetate (SATA)-modified mouse anti human E-selectin antibodies to the distal ends of the maleimidyl (Mal)-PEG groups. In cell binding assays, these immunoliposomes bound specifically to TNF-α activated endothelial cells. Upon internalization, rapamycin loaded immunoliposomes inhibited proliferation and migration of endothelial cells, as well as expression of inflammatory mediators. Our findings demonstrate that rapamycin-loaded immunoliposomes can specifically inhibit inflammatory responses in inflamed endothelial cells. [ABSTRACT FROM AUTHOR]

Squamous cell carcinoma (SCC) is a malignant tumor in which epidermal growth factor receptor (EGFR) overexpression is associated with poor prognosis and malignancy. For SCC treatment, cetuximab, an anti-EGFR antibody, is administered in combination with a chemotherapeutic drug for improved efficacy. In this work, an EGFR-targeted immunoliposome loaded with 5-fluorouracil (5- FU) was developed to allow co-administration of the antibody and the chemotherapeutic agent and selective delivery to SCC cells. Topically applied iontophoresis and subcutaneous injections of the 5-FU-loaded immunoliposomes were employed in an SCC xenograft animal model to evaluate the influence of the administration route on therapeutic efficacy. In vitro, cellular uptake of cetuximab-immunoliposomes by EGFR-positive SCC cells was 3.5-fold greater than the uptake of control liposomes. Skin penetration studies showed that iontophoresis of immunoliposomes doubled the 5-FU penetration into the viable epidermis compared with the same treatment with control liposomes. In vivo, subcutaneous injection of immunoliposomes reduced tumor volume by >60% compared with the negative control and approximately 50% compared with the 5-FU solution and control liposome treatments. Interestingly, topical administration via iontophoresis improved tumor reduction by almost 2-fold compared with subcutaneous administration of 5-FU solution and control liposomes but was equally effective for the immunoliposome treatment. However, histological analysis showed that iontophoresis of immunoliposomes was more effective than subcutaneous injection in reducing cell proliferation, resulting in cells with less aggressive characteristics. In conclusion, topical administration of immunoliposomes containing 5-FU using iontophoresis is a promising strategy for SCC treatment. [ABSTRACT FROM AUTHOR]

Liposomal formulations entrapping a vast number of molecules have improved cancer therapies overcoming certain pharmacokinetic (PK) and pharmacodynamic limitations, many of which are associated with tumor characteristics. In this context, immunoliposomes represent a new strategy that has been widely investigated in preclinical cancer models with promising results, although few have reached the stage of clinical trials. This contrasts with the emerging clinical application of monoclonal antibodies (mAbs). This formulation allows the conjugation of different mAbs or antibody derivatives, such as monovalent variable fragments Fab’, to the polymers covering the surface of liposomes. The combination of this targeting strategy together with drug encapsulation in a single formulation may contribute to enhance the efficacy of these associated agents, reducing their toxicities. In this paper we will consider how factors such as particle size, lipid composition and charge, lipid-polymer conjugation, method of production and type of ligand for liposome coupling influence the efficacy of these formulations. Furthermore, the high inter-individual variability in the tumor microenvironment, as well as the poor experimental designs for the PK characterization of liposomes, make the establishment of the relationship between plasma or tumor concentrations and efficacy difficult. Thus, adequate dosing regimens and patient stratification regarding the target expression may contribute to enhance the possibility of incorporating these immunoliposomes into the therapeutic arsenal for cancer treatments. All these issues will be briefly dealt with here, together with a section showing the state of the art of those targeted liposomes that are coming up for testing in clinical trials. Finally, some insights into future developments such as the combination of specificity and controlled release, based on the application of different stimuli, for the manipulation of stability and cargo release, will be offered. This has been included in order to highlight the new opportunities for targeted liposomes, including immunoliposomes. [ABSTRACT FROM AUTHOR]

Development and characterization of LAM and DTG loaded liposomes conjugated anti-CD4 antibody and peptide dendrimer (PD2) to improve the therapeutic efficacy and to achieve targeted treatment for HIV infection. A 2-level full factorial design was used to optimize the preparation of dual drug loaded liposomes. Optimized dual drug loaded ligand conjugated liposomes were assessed for their cytotoxicity and cell internalization on TZM-bl cells. Anti-HIV efficiency of the dual drug loaded liposomes were screened for their inhibitory potential in TZM-bl cells and the activities were confirmed using Peripheral Blood Mononuclear Cells (PBMCs). The particle size of the optimized dual drug-loaded liposomes was 133.7 ± 4.04 nm, and the spherical morphology of the liposomes was confirmed by TEM analysis. The entrapment efficiency was 34 ± 4.9 % and 54 ± 1.8 % for LAM and DTG, respectively, and a slower in vitro release of LAM and DTG was observed when entrapped into liposomes. The cytotoxicity of the dual drug loaded liposomes was similar to the cytotoxicity of free drug solutions. Conjugation of anti-CD4 antibody and PD2 did not significantly influence the cytotoxicity but it enhanced the uptake of liposomes into the cells. Conjugated dual drug loaded liposomes exhibited better HIV inhibition with lower IC 50 values (0.0003 ± 0.0002 μg/mL) compared to their free drug solutions (0.002 ± 0.001 μg/mL). The liposomal formulations have shown similar activities in both screening and confirmatory cell-based assays. The results demonstrated the cell targeting ability of dual drug loaded liposomes conjugated with anti-CD4 antibody and peptide dendrimer. Conjugated liposomes also improved anti-HIV efficiency of LAM and DTG. [Display omitted] [ABSTRACT FROM AUTHOR]

Combination therapies, where two drugs acting through different mechanisms are administered simultaneously, are one of the most efficient approaches currently used to treat malaria infections. However, the different pharmacokinetic profiles often exhibited by the combined drugs tend to decrease treatment efficacy as the compounds are usually eliminated from the circulation at different rates. To circumvent this obstacle, we have engineered an immunoliposomal nanovector encapsulating hydrophilic and lipophilic compounds in its lumen and lipid bilayer, respectively. The antimalarial domiphen bromide has been encapsulated in the liposome membrane with good efficiency, although its high IC50 of ca. 1 µM for living parasites complicates its use as immunoliposomal therapy due to erythrocyte agglutination. The conjugation of antibodies against glycophorin A targeted the nanocarriers to Plasmodium-infected red blood cells and to gametocytes, the sole malaria parasite stage responsible for the transmission from the human to the mosquito vector. The antimalarials pyronaridine and atovaquone, which block the development of gametocytes, have been co-encapsulated in glycophorin A-targeted immunoliposomes. The co-immunoliposomized drugs have activities significantly higher than their free forms when tested in in vitro Plasmodium falciparum cultures: Pyronaridine and atovaquone concentrations that, when encapsulated in immunoliposomes, resulted in a 50% inhibition of parasite growth had no effect on the viability of the pathogen when used as free drugs.

In this paper, we report the conjugation of the humanized monoclonal antibody nimotuzumab with cisplatin-loaded liposomes and thein vitroevaluation of its affinity for tumor cells. The conjugation procedure was performed through derivatization of nimotuzumab with N-succinimidyl S-acetylthioacetate (SATA) followed by a covalent attachment with maleimide groups at the end of PEG-DSPE chains located at the membrane of pre-formed liposomes. Confocal microscopy was performed to evaluate the immunoliposome affinity for EGFR antigens from human epidermoid carcinoma (A-431) and normal lung (MRC-5) cell lines. Results showed that the procedures implemented in this work do not affect the capability of the nimotuzumab-immunoliposomes to recognize the tumor cells, which overexpress the EGFR antigens. [ABSTRACT FROM PUBLISHER]

Most drugs currently entering the clinical pipeline for severe malaria therapeutics are of lipophilic nature, with a relatively poor solubility in plasma and large biodistribution volumes. Low amounts of these compounds do consequently accumulate in circulating Plasmodium -infected red blood cells, exhibiting limited antiparasitic activity. These drawbacks can in principle be satisfactorily dealt with by stably encapsulating drugs in targeted nanocarriers. Here this approach has been adapted for its use in immunocompetent mice infected by the Plasmodium yoelii 17XL lethal strain, selected as a model for human blood infections by Plasmodium falciparum . Using immunoliposomes targeted against a surface protein characteristic of the murine erythroid lineage, the protocol has been applied to two novel antimalarial lipophilic drug candidates, an aminoquinoline and an aminoalcohol. Large encapsulation yields of >90% were obtained using a citrate-buffered pH gradient method and the resulting immunoliposomes reached in vivo erythrocyte targeting and retention efficacies of >80%. In P. yoelii -infected mice, the immunoliposomized aminoquinoline succeeded in decreasing blood parasitemia from severe to uncomplicated malaria parasite densities (i.e. from ≥25% to ca. 5%), whereas the same amount of drug encapsulated in non-targeted liposomes had no significant effect on parasite growth. Pharmacokinetic analysis indicated that this good performance was obtained with a rapid clearance of immunoliposomes from the circulation (blood half-life of ca. 2 h), suggesting a potential for improvement of the proposed model. [ABSTRACT FROM AUTHOR]

Nanoparticles, especially liposomes, have gained prominence in the field of drug delivery for the treatment of human diseases, particularly cancer; they provide several advantages, including controlled drug release, protection of the drug against degradation, improved pharmacokinetics, long circulation, and passive targeting to tumors and inflammatory sites due to the enhanced permeability and retention effect. The functionalization of liposomes with monoclonal antibodies or antibody fragments to generate immunoliposomes has emerged as a promising strategy for targeted delivery to and uptake by cells overexpressing the antigens to these antibodies, with a consequent reduction in side effects. In this review, we address functionalization strategies for the non-covalent and covalent attachment of monoclonal antibodies and their fragments to liposomal surfaces. The main reaction occurs between the sulfhydryl groups of thiolated antibodies and maleimide-containing liposomes. Furthermore, we explore the main targeting possibilities with these ligands for the treatment of a variety of pathologies, including HER2- and EGFR-positive cancers, inflammatory and cardiovascular diseases, infectious diseases, and autoimmune and neurodegenerative diseases, which have not previously been reviewed together. Overall, many studies have shown selective delivery of immunoliposomes to target cells, with promising in vivo results, particularly for cancer treatment. Although clinical trials have been conducted, immunoliposomes have not yet received clinical approval. However, immunoliposomes are promising formulations that are expected to become available for therapeutic use after clinical trials prove their safety and efficacy, and after scaling issues are resolved. [ABSTRACT FROM AUTHOR]

Background Immunoliposomes have been used to deliver MR contrast agents to cancer tissue by targeting tumor associated antigens, thus enabling the visualization of biological processes at the cellular level. Purpose To develop and evaluate the feasibility of specific HER2 targeted liposomal MR contrast agent. Material and Methods Gd-loaded anti-HER2 immunolipomes (Gd-ILs) and non-targeted PEGylated liposomes (Gd-NTLs) were prepared and characterized. Tumor bearing animals were randomized into three groups: Gd- ILs, Gd- NTLs and gadobutrol. Animals were imaged prior and 5, 15, 60, 120 and 180 min after i.v. injection of different contrast agents. The signal intensity enhancement percentage, signal- to- noise ratio and contrast- to -noise ratio was used to qualify tumor enhancement of different groups. After imaging, tumors were excised for histological examination. Results In vivo dynamic MR images, the specific targeted contrast agent bound to tumor tissue and result in a gradual and persisting enhancement for at least 3 hours in mice bearing tumor xenografts, reaching a maximum of 87.7% enhancement after 120 min post-injection. Gd-ILs demonstrated superior tumor enhancement over control non target contrast agent and gadobutrol in HER2 overexpressing tumors at 60, 120 and 180 min post- injection. The SNR and CNR of Gd-ILs in the tumors were significantly greater than that of Gd-NTLs at 60, 120, 180 min post- injection. Conclusion The results indicate the feasibility of Gd-ILs providing prolonged circulation, specific tumor enhancement and cancer cell recognition as targeted contrast agent. [ABSTRACT FROM AUTHOR]