An integrated assessment of morphology, size, and complement activation of the PEGylated liposomal doxorubicin products Doxil®, Caelyx®, DOXOrubicin, and SinaDoxosome

Scalable microfluidic method for tunable liposomal production by a design of experiment approach

Liposomes constitute a widespread drug delivery platform, gaining more and more attention from the pharmaceutical industry and process development scientists. Their large-scale production as medicinal products for human use is all but trivial, especially when parenteral administration is required. In this study an off-the-shelf microfluidic system and a methodological approach are presented for the optimization, validation and scale-up of highly monodisperse liposomes manufacturing. Starting from a Doxil®-like formulation (HSPC, MPEG-DSPE and cholesterol), a rational approach (Design of Experiments, DoE) was applied for the screening of the process parameters affecting the quality attributes of the product (mainly size and polydispersity). Additional DoEs were conducted to determine the effect of critical process parameters "CPPs" (cholesterol concentration, total flow rate "TFR" and flow rate ratio "FRR"), thus assessing the formulation and process robustness. A scale-up was then successfully accomplished. The procedure was applied to a Marqibo®-like formulation as well (sphingomyelin and cholesterol) to show the generality of the proposed formulation, process development and scale-up approach. The application of the system and method herein presented enables the large-scale manufacturing of liposomes, in compliance with the internationally recognized regulatory standards for pharmaceutical development (Quality by Design).

Perilous paradigm of graphene oxide and its derivatives in biomedical applications: Insight to immunocompatibility

With advancements in nanotechnology and innovative materials, Graphene Oxide nanoparticles (GONP) have attracted lots of attention among the diverse types of nanomaterials owing to their distinctive physicochemical characteristics. However, the usage at scientific and industrial level has also raised concern to their toxicological interaction with biological system. Understanding these interactions is crucial for developing guidelines and recommendations for applications of GONP in various sectors, like biomedicine and environmental technologies. This review offers crucial insights and an in-depth analysis to the biological processes associated with GONP immunotoxicity with multiple cell lines including human whole blood cultures, dendritic cells, macrophages, and multiple cancer cell lines. The complicated interactions between graphene oxide nanoparticles and the immune system, are highlighted in this work, which reveals a range of immunotoxic consequences like inflammation, immunosuppression, immunostimulation, hypersensitivity, autoimmunity, and cellular malfunction. Moreover, the immunotoxic effects are also highlighted with respect to in vivo models like mice and zebrafish, insighting GO Nanoparticles' cytotoxicity. The study provides invaluable review for researchers, policymakers, and industrialist to understand and exploit the beneficial applications of GONP with a controlled measure to human health and the environment.

Liposomes Enhance the Immunological Activity of Polygonatum Cyrtonema Hua Polysaccharides

Poor stability and difficult uptake of natural polysaccharides have been the main problems in their application. The purpose of this study was to optimize the preparation conditions of Polygonatum cyrtonema Hua polysaccharides liposomes (PCPL) and to investigate the immune enhancement activity of PCPL in vitro and in vivo, with a view to discovering new ways of natural polysaccharide application. The optimal preparation conditions of PCPL were as follows: the adding amount of Tween 80 of 0.5 %, the ultrasound time of 2 min and the ultrasound times of once. Under these conditions, the entrapment efficiency, drug loading rate and particle size of PCPL were 38.033 %±0.050, 2.172 %±0.003 and 146 nm, which indicated that PCPL with small particle size could be prepared by the reverse-phase evaporation method. Furthermore, PCPL promoted proliferation, phagocytosis, and secretion of nitric oxide and related cytokines in RAW264.7 cells. Moreover, PCPL improved spleen and thymus indices, increased the number or proportion of red blood cells, platelets, and lymphocytes in the blood, and ameliorated spleen and thymus atrophy in immunosuppressed mice. This study provides a new idea for applying Polygonatum cyrtonema Hua polysaccharides (PCP) and references for studying other polysaccharides.

Surface-modified cationic liposomes with a matrix metalloproteinase-degradable polyethylene glycol derivative improved doxorubicin delivery in murine colon cancer

PEGylation is a commonly used approach to prolong the blood circulation time of cationic liposomes. However, PEGylation is associated with the "PEG dilemma", which hinders binding and uptake into tumor cells. The cleavable PEG products are a possible solution to this problem. In the current research, doxorubicin-loaded cationic liposomes (Dox-CLs) surface-conjugated with a matrix metalloproteinase-2 (MMP-2)-sensitive octapeptide linker-PEG derivative were prepared and compared to non-PEGylated and PEGylated CLs in terms of size, surface charge, drug encapsulation and release, uptake, in vivo pharmacokinetics, and anticancer efficacy. It was postulated that PEG deshielding in response to the overexpressed MMP-2 in the tumor microenvironment increases the interaction of protected CLs with cellular membranes and improves their uptake by tumor cells/vasculature. MMP2-responsive Dox-CLs had particle sizes of ∼115-140 nm, surface charges of ∼+25 mV, and encapsulation efficiencies of ∼85-95%. In vitro cytotoxicity assessments showed significantly enhanced uptake and cytotoxicity of PEG-cleavable CLs compared to their non-cleavable PEG-coated counterparts or Caelyx®. Also, the chick chorioallantoic membrane assay showed great antiangiogenesis ability of Dox-CLs leading to target and prevent tumor neovascularization. Besides, in vivo studies showed an effective therapeutic efficacy of PEG-cleavable Dox-CLs in murine colorectal cancer with negligible hematological and histopathological toxicity. Altogether, our results showed that MMP2-responsive Dox-CLs could be served as a promising approach to improve tumor drug delivery and uptake.

Revolutionizing transdermal drug delivery: unveiling the potential of cubosomes and ethosomes

The area of drug delivery systems has witnessed significant advancements in recent years, with a particular focus on improving efficacy, stability, and patient compliance. Transdermal drug delivery offers numerous benefits compared to conventional methods of drug administration through the skin. It helps in avoiding gastric irritation, hepatic first-pass metabolism, and gastric degradation of the drug. It bypasses the gastrointestinal tract, eliminating the risk of first-pass metabolism and allowing drugs to be administered without being affected by pH, enzymes, or intestinal bacteria. Additionally, it allows for sustained release of the drug, is noninvasive, and enhances patient adherence to the treatment regimen. The transdermal drug delivery system (TDDS) can serve as an alternative route for drug administration in individuals who cannot tolerate oral medications, experience nausea, or are unconscious. When compared to intravenous, hypodermic, and other parenteral routes, TDDS stands out due to its ability to eliminate pain, reduce the risk of infection, and prevent disease transmission associated with needle reuse. Consequently, the overall patient compliance is significantly improved with the utilization of TDDS. Among the noteworthy developments are cubosomes and ethosomes, two distinct yet promising carriers that have garnered attention for their unique properties. In conclusion, this review synthesizes the current knowledge on cubosomes and ethosomes, shedding light on their individual strengths and potential synergies. The exploration of their application in various therapeutic areas underscores their versatility and establishes them as key players in the evolving landscape of drug delivery systems.

Intrinsic and Dynamic Heterogeneity of Nonlamellar Lyotropic Liquid Crystalline Nanodispersions

Nonlamellar lyotropic liquid crystalline (LLC) nanoparticles are a family of versatile nano-self-assemblies, which are finding increasing applications in drug solubilization and targeted drug delivery. LLC nanodispersions are heterogeneous with discrete nanoparticle subpopulations of distinct internal architecture and morphology, frequently coexisting with micelles and/or vesicles. Diversity in the internal architectural repertoire of LLC nanodispersions grants versatility in drug solubilization, encapsulation, and release rate. However, drug incorporation contributes to the heterogeneity of LLC nanodispersions, and on exposure to biological media, LLC nanodispersions often undergo nanostructural and morphological transformations. From a pharmaceutical perspective, coexistence of multiple types of nanoparticles with diverse structural attributes, together with media-driven transformations in colloidal characteristics, brings challenges in dissecting biological and therapeutic performance of LLC nanodispersions in a spatiotemporal manner. Here, we outline innate and acquired heterogeneity of LLC nanodispersions and discuss technological developments and alternative approaches needed to improve homogeneity of LLC formulations for drug delivery applications.

Lyotropic liquid crystalline 2D and 3D mesophases: Advanced materials for multifunctional anticancer nanosystems

Cancer remains a leading cause of mortality. Despite significant breakthroughs in conventional therapies, treatment is still far from ideal due to high toxicity in normal tissues and therapeutic inefficiency caused by short drug lifetime in the body and resistance mechanisms. Current research moves towards the development of multifunctional nanosystems for delivery of chemotherapeutic drugs, bioactives and/or radionuclides that can be combined with other therapeutic modalities, like gene therapy, or imaging to use in therapeutic screening and diagnosis. The preparation and characterization of Lyotropic Liquid Crystalline (LLC) mesophases self-assembled as 2D and 3D structures are addressed, with an emphasis on the unique properties of these nanoassemblies. A comprehensive review of LLC nanoassemblies is also presented, highlighting the most recent advances and their outstanding advantages as drug delivery systems, including tailoring strategies that can be used to overcome cancer challenges. Therapeutic agents loaded in LLC nanoassemblies offer qualitative and quantitative enhancements that are superior to conventional chemotherapy, particularly in terms of preferential accumulation at tumor sites and promoting enhanced cancer cell uptake, lowering tumor volume and weight, improving survival rates, and increasing the cytotoxicity of their loaded therapeutic agents. In terms of quantitative anticancer efficacy, loaded LLC nanoassemblies reduced the IC50 values from 1.4-fold against lung cancer cells to 125-fold against ovarian cancer cells.

Multi-ligand functionalized blood-to-tumor sequential targeting strategies in the field of glioblastoma nanomedicine

Glioblastoma (GBM) is an unmet clinical need characterized by a standard of care (SOC) 5-year survival rate of only 5%, and a treatment mostly palliative. Significant hurdles in GBM therapies include an effective penetration of therapeutics through the brain protective barrier, namely the blood-brain barrier (BBB), and a successful therapeutic delivery to brain-invading tumor cells post-BBB crossing. These hurdles, along with the poor prognosis and critical heterogeneity of the disease, have shifted attention to treatment modalities with capacity to precisely and sequentially target (i) BBB cells, inducing blood-to-brain transport, and (ii) GBM cells, leading to a higher therapeutic accumulation at the tumor site. This sequential targeting allows therapeutic molecules to reach the brain parenchyma and compromise molecular processes that support tumor cell invasion. Besides improving formulation and pharmacokinetics constraints of drugs, nanomedicines offer the possibility of being surface functionalized with multiple possibilities of targeting ligands, while delivering the desired therapeutic cargos to the biological sites of interest. Targeting ligands exploit the site-specific expression or overexpression of specific molecules on BBB and GBM cells, triggering brain plus tumor transport. Since the efficacy of single-ligand functionalized nanomedicines is limited due to the GBM anatomical site (brain) and disease complexity, this review presents an overview of multi-ligand functionalized, BBB and GBM sequentially- and dual-targeted nanomedicines reported in literature over the last 10 years. The role of the BBB in GBM progression, treatment options, and the multiple possibilities of currently available targeting ligands will be summarized. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Multicomponent-Loaded Vesosomal Drug Carrier for Controlled and Sustained Compound Release

Liposomes have been extensively adopted in drug delivery systems with clinically approved formulations. However, hurdles remain in terms of loading multiple components and precisely controlling their release. Herein, we report a vesosomal carrier composed of liposomes encapsulated inside the core of another liposome for the controlled and sustained release of multiple contents. The inner liposomes are made of lipids with different compositions and are co-encapsulated with a photosensitizer. Upon induction of reactive oxygen species (ROS), the contents of the liposomes are released, with each type of liposome displaying distinct kinetics due to the variance in lipid peroxidation for differential structural deformation. In vitro experiments demonstrated immediate content release from ROS-vulnerable liposomes, followed by sustained release from ROS-nonvulnerable liposomes. Moreover, the release trigger was validated at the organismal level using Caenorhabditis elegans. This study demonstrates a promising platform for more precisely controlling the release of multiple components.

Characterization of lipid-based nanomedicines at the single-particle level

Lipid-based nanomedicines (LBNMs), including liposomes, lipid nanoparticles (LNPs) and extracellular vesicles (EVs), are recognized as one of the most clinically acceptable nano-formulations. However, the bench-to-bedside translation efficiency is far from satisfactory, mainly due to the lack of in-depth understanding of their physical and biochemical attributes at the single-particle level. In this review, we first give a brief introduction of LBNMs, highlighting some milestones and related scientific and clinical achievements in the past several decades, as well as the grand challenges in the characterization of LBNMs. Next, we present an overview of each category of LBNMs as well as the core properties that largely dictate their biological characteristics and clinical performance, such as size distribution, particle concentration, morphology, drug encapsulation and surface properties. Then, the recent applications of several analytical techniques including electron microscopy, atomic force microscopy, fluorescence microscopy, Raman microscopy, nanoparticle tracking analysis, tunable resistive pulse sensing and flow cytometry on the single-particle characterization of LBNMs are thoroughly discussed. Particularly, the comparative advantages of the newly developed nano-flow cytometry that enables quantitative analysis of both the physical and biochemical characteristics of LBNMs smaller than 40 nm with high throughput and statistical robustness are emphasized. The overall aim of this review article is to illustrate the importance, challenges and achievements associated with single-particle characterization of LBNMs.

Catalytic Nanomedicine as a Therapeutic Approach to Brain Tumors: Main Hypotheses for Mechanisms of Action

Glioblastoma multiforme (GBM) is the most aggressive primary malignant tumor of the brain. Although there are currently a wide variety of therapeutic approaches focused on tumor elimination, such as radiotherapy, chemotherapy, and tumor field therapy, among others, the main approach involves surgery to remove the GBM. However, since tumor growth occurs in normal brain tissue, complete removal is impossible, and patients end up requiring additional treatments after surgery. In this line, Catalytic Nanomedicine has achieved important advances in developing bionanocatalysts, brain-tissue-biocompatible catalytic nanostructures capable of destabilizing the genetic material of malignant cells, causing their apoptosis. Previous work has demonstrated the efficacy of bionanocatalysts and their selectivity for cancer cells without affecting surrounding healthy tissue cells. The present review provides a detailed description of these nanoparticles and their potential mechanisms of action as antineoplastic agents, covering the most recent research and hypotheses from their incorporation into the tumor bed, internalization via endocytosis, specific chemotaxis by mitochondrial and nuclear genetic material, and activation of programmed cell death. In addition, a case report of a patient with GBM treated with the bionanocatalysts following tumor removal surgery is described. Finally, the gaps in knowledge that must be bridged before the clinical translation of these compounds with such a promising future are detailed.

Perspectives on complement and phagocytic cell responses to nanoparticles: From fundamentals to adverse reactions

The complement system, professional phagocytes and other cells such as Natural killer cells and mast cells are among the important components of the innate arm of the immune system. These constituents provide an orchestrated array of defences and responses against tissue injury and foreign particles, including nanopharmaceuticals. While interception of nanopharmaceuticals by the immune system is beneficial for immunomodulation and treatment of phagocytic cell disorders, it is imperative to understand the multifaceted mechanisms by which nanopharmaceuticals interacts with the immune system and evaluate the subsequent balance of beneficial versus adverse reactions. An example of the latter is adverse infusion reactions to regulatory-approved nanopharmaceuticals seen in human subjects. Here, we discuss collective opinions and findings from our laboratories in mapping nanoparticle-mediated complement and leucocyte/macrophage responses.

Development and DoE-ANN based optimization of novel swellable matrix-diffusible doxorubicin loaded zinc oxide nanoflowers using sonochemical-precipitation method

This research aimed to acquire doxorubicin loaded zinc oxide nanoflowers (DOX-ZnO-NFs) for intracellular drug cargo possessing a synergistic in-vitro anticancer activity with minimal toxicity. Zinc is the main inorganic metallic component of various enzyme systems and has the possibility of fabrication into the diverse nano-structural forms. An easy absorption and extensive tissue distribution of zinc have made it unique candidate for drug delivery system. Hence, the zinc oxide nanoflowers were prepared with sonochemical-precipitation. The developed system was characterized using the reported methods and was optimized employing design of experiment, coupled with artificial neural network approach. The optimized nanoflowers (DOX-ZnO-NFV) were anionic with particle size of 24 ± 0.05 nm, polydispersity index of <0.5, a zeta potential of -25.68 ± 0.16 mV, yield of 87.40% and encapsulation efficiency of 85.25%. DOX-ZNO-NFV depicted sustained DOX release, around 65.413% release in 30 h at pH 7.4 and assumed Weibull model with its derived parameters, a and b of 22.77 and 0.918, respectively. DOX-ZnO-NFV remained stable on storage for 3 months at 4° C/50% RH and 25° C/60% RH. DOX-ZnO-NFV displayed a zone of inhibition of 13.50 ± 1.25 mm and 25.50 ± 0.98 mm, respectively against gram-positive Staphylococcus aureus and gram-negative Escherichia coli strains, presenting the nanoflowers as self-preservative. DOX-ZnO-NFV exhibited higher in-vitro anticancer activity in Henrietta Lacks cell line, with least hemolysis compared to the free DOX and ZnO-NF. Thus, doxorubicin loaded zinc oxide nanoflowers envisioned to act as better chemotherapeutic cargos with the maximize anticancer activity and minimal toxicity.

An expanding horizon of complex injectable products: development and regulatory considerations

There has been a constant evolution in the pharmaceutical market concerning the new technologies imbibed in delivering drug substances for various indications. This is either market-driven or technology-driven to improve the overall therapeutic efficacy and patients' quality of life. The pharmaceutical industry has experienced rapid growth in the area of complex injectable products because of their effectiveness in the unmet market. These novel parenteral products, viz, the nanoparticles, liposomes, microspheres, suspensions, and emulsions, have proven their worth as "Safe and Effective" products. However, the underlying challenges involved in the development, scalability, and characterization of these injectable products are critical. Moreover, the guidelines available do not provide a clear understanding of these complex products, making it difficult to anticipate the regulatory requirements. Thus, it becomes imperative to comprehend the criticalities and develop an understanding of these products. This review discusses various complexities involved in the parenteral products such as complex drug substances, excipients, dosage forms, drug administration devices like pre-filled syringes and injector pens, and its different characterization tools and techniques. The review also provides a brief discussion on the regulatory aspects and associated hurdles with other parenteral products.

Doxorubicin-loaded liposomes surface engineered with the matrix metalloproteinase-2 cleavable polyethylene glycol conjugate for cancer therapy

Background

Colorectal cancer is one of the prominent leading causes of fatality worldwide. Despite recent advancements within the field of cancer therapy, the cure rates and long-term survivals of patients suffering from colorectal cancer have changed little. The application of conventional chemotherapeutic agents like doxorubicin is limited by some drawbacks such as cardiotoxicity and hematotoxicity. Therefore, nanotechnology has been exploited as a promising solution to address these problems. In this study, we synthesized and compared the anticancer efficacy of doxorubicin-loaded liposomes that were surface engineered with the 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-matrix metalloproteinase-2 (MMP-2) cleavable peptide-polyethylene glycol (PEG) conjugate. The peptide linker was used to cleave in response to the upregulated MMP-2 in the tumor microenvironment, thus exposing a positive charge via PEG-deshielding and enhancing liposomal uptake by tumor cells/vasculature. Liposomal formulations were characterized in terms of size, surface charge and morphology, drug loading, release properties, cell binding and uptake, and cytotoxicity.

Results

The formulations had particle sizes of ~ 100-170 nm, narrow distribution (PDI ˂ 0.2), and various surface charges (- 10.2 mV to + 17.6 mV). MMP-2 overexpression was shown in several cancer cell lines (C26, 4T1, and B16F10) as compared to the normal NIH-3T3 fibroblast cells by gelatin zymography and qRT-PCR. In vitro results demonstrated enhanced antitumor efficacy of the PEG-cleavable cationic liposomes (CLs) as compared to the commercial Caelyx^® (up to fivefold) and the chick chorioallantoic membrane assay showed their great antiangiogenesis potential to target and suppress tumor neovascularization. The pharmacokinetics and efficacy studies also indicated higher tumor accumulation and extended survival rates in C26 tumor-bearing mice treated with the MMP-2 cleavable CLs as compared to the non-cleavable CLs with no remarkable sign of toxicity in healthy tissues.

Conclusion

Altogether, the MMP-2-cleavable CLs have great potency to improve tumor-targeted drug delivery and cellular/tumor-vasculature uptake which merits further investigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12645-023-00169-8.

Folded, undulating, and fibrous doxorubicin sulfate crystals in liposomes

High-resolution cryogenic transmission electron microscopy (cryo-TEM) evidenced that doxorubicin sulfate crystals in liposomes (prepared by remote loading with ammonium sulfate) form folded, undulating, and fibrous crystals with a diameter of approximately 2.4 nm. An undulating, fibrous crystal considered to be undergrowth, in addition to bundles of fibrous crystals, was also observed in doxorubicin-loaded liposomes. This explains the validity of the formation of doxorubicin sulfate crystals of various shapes, e.g., curved, U-shaped, or circular, in addition to cylinder and/or rod-like crystals reported in the literature. Liposomes that do not contain crystals have inner aqueous phases with high electron density, suggesting that the doxorubicin is remotely loaded and remains as a solute without precipitation.

Long-Circulating and Fusogenic Liposomes Loaded with Paclitaxel and Doxorubicin: Effect of Excipient, Freezing, and Freeze-Drying on Quality Attributes

Liposomes can increase plasma half-life, enhance targeting, and diminish the side-effects of loaded drugs. On the downside, physical and chemical instabilities of dispersions often result in a reduced lifespan, which limits their availability on the market. Solid formulations obtained by freeze-drying can immobilize vesicles and provide extended shelf life. For both processes, the choice of excipients and process parameters are crucial to protect the carrier layers against tension caused by freezing and/or dehydration. The aim of this work is to evaluate the influence of freezing and drying parameters, besides excipient choice, to obtain solid long-circulating and fusogenic liposomes (LCFL-PTX/DXR) co-encapsulating paclitaxel (PTX) and doxorubicin (DXR) at a synergistic ratio (1:10).

METHODS

LCFL-PTX/DXR was evaluated by freeze-drying microscopy (glass transition, Tg'), differential scanning calorimetry (collapse temperature, Tc), freeze-thawing and freeze-drying processes. Freeze-dried samples were evaluated by thermogravimetry (residual moisture) and the resuspended liposomes were characterized in terms of size, polydispersity index (PI), zeta potential (ZP), and drug content. Liposomes morphology was evaluated by cryomicroscopy.

RESULTS

Trehalose protected PTX cargo upon freeze-thawing and more than 80% of the original DXR retention. The formulations with trehalose resulted in a cake with 5-7% of moisture content (200-240 nm); 44-60% of PTX retention, and 25-35% of DXR retention, with the variations caused by cryoprotector concentration and process changes.

CONCLUSIONS

Trehalose protected liposome integrity, maintaining PTX retention and most of DXR upon freeze-thawing. Freeze-drying reduced the retention of both drugs inside all liposomes, whereas formulation with trehalose presented minor losses. Therefore, this frozen formulation is an alternative product option, with no need for manipulation before use.

Spotlight on Photoactivatable Liposomes beyond Drug Delivery: An Enabler of Multitargeting of Molecular Pathways

The potential of photoactivating certain molecules, photosensitizers (PS), resulting in photochemical processes, has long been realized in the form of photodynamic therapy (PDT) for the management of several cancerous and noncancerous pathologies. With an improved understanding of the photoactivation process and its broader implications, efforts are being made to exploit the various facets of photoactivation, PDT, and the associated phenomenon of photodynamic priming in enhancing treatment outcomes, specifically in cancer therapeutics. The parallel emergence of nanomedicine, specifically liposome-based nanoformulations, and the convergence of the two fields of liposome-based drug delivery and PDT have led to the development of unique hybrid systems, which combine the exciting features of liposomes with adequate complementation through the photoactivation process. While initially liposomes carrying photosensitizers (PSs) were developed for enhancing the pharmacokinetics and the general applicability of PSs, more recently, PS-loaded liposomes, apart from their utility in PDT, have found several applications including enhanced targeting of drugs, coloading multiple therapeutic agents to enhance synergistic effects, imaging, priming, triggering drug release, and facilitating the escape of therapeutic agents from the endolysosomal complex. This review discusses the design strategies, potential, and unique attributes of these hybrid systems, with not only photoactivation as an attribute but also the ability to encapsulate multiple agents for imaging, biomodulation, priming, and therapy referred to as photoactivatable multiagent/inhibitor liposomes (PMILS) and their targeted versions─targeted PMILS (TPMILS). While liposomes have formed their own niche in nanotechnology and nanomedicine with several clinically approved formulations, we try to highlight how using PS-loaded liposomes could address some of the limitations and concerns usually associated with liposomes to overcome them and enhance their preclinical and clinical utility in the future.

Nanometer- and angstrom-scale characteristics that modulate complement responses to nanoparticles

The contribution of the complement system to non-specific host defence and maintenance of homeostasis is well appreciated. Many particulate systems trigger complement activation but the underlying mechanisms are still poorly understood. Activation of the complement cascade could lead to particle opsonisation by the cleavage products of the third complement protein and might promote inflammatory reactions. Antibody binding in a controlled manner and/or sensing of particles by the complement pattern-recognition molecules such as C1q and mannose-binding lectin can trigger complement activation. Particle curvature and spacing arrangement/periodicity of surface functional groups/ligands are two important parameters that modulate complement responses through multivalent engagement with and conformational regulation of surface-bound antibodies and complement pattern-recognition molecules. Thus, a better fundamental understanding of nanometer- and angstrom-scale parameters that modulate particle interaction with antibodies and complement proteins could portend new possibilities for engineering of particulate drug carriers and biomedical platforms with tuneable complement responses and is discussed here.

Covalent Organic Frameworks as Nanocarriers for Improved Delivery of Chemotherapeutic Agents

Cancer has become one of the main causes of death worldwide. Chemotherapy as one of the main therapy modalities is very unsatisfactory. The various nanocarriers have brought new opportunities for effective tumor treatment. However, most of the current nanocarriers still suffer from low efficiency and confront significant challenges in overcoming multiple biological barriers. Compared with conventional nanocarriers, covalent organic frameworks (COFs) with unique and attractive features exhibited great potential to serve as a promising platform for anticancer drug delivery. In this review, we first summarize the strategies and challenges of nanocarriers for cancer chemotherapy and then highlight the recent advances in COF-based nanocarriers for improved delivery of chemotherapeutic agents. Finally, the challenges remaining for COF-based nanocarriers for clinical applications are outlined.

The role of size in PEGylated liposomal doxorubicin biodistribution and anti-tumour activity

The size of nanoliposome‐encapsulated drugs significantly affects their therapeutic efficacy, biodistribution, targeting ability, and toxicity profile for the cancer treatment. In the present study, the biodistribution and anti‐tumoral activity of PEGylated liposomal Doxorubicin (PLD) formulations with different sizes were investigated. First, 100, 200, and 400 nm PLDs were prepared by remote loading procedure and characterised for their size, zeta potential, encapsulation efficacy, and release properties. Then, in vitro cellular uptake and cytotoxicity were studied by flow cytometry and MTT assay, and compared with commercially available PLD Caelyx^®. In vivo studies were applied on BALB/c mice bearing C26 colon carcinoma. The cytotoxicity and cellular uptake tests did not demonstrate any statistically significant differences between PLDs. The biodistribution results showed that Caelyx^® and 100 nm liposomal formulations had the most doxorubicin (Dox) accumulation in the tumour tissue and, as a result, considerably suppressed tumour growth compared with 200 and 400 nm PLDs. In contrast, larger nanoparticles (200 and 400 nm formulations) had more accumulation in the liver and spleen. This study revealed that 90 nm Caelyx^® biodistribution profile led to the stronger anti‐tumour activity of the drug and hence significant survival extension, and showed the importance of vesicle size in the targeting of nanoparticles to the tumour microenvironment for the treatment of cancer.

Beyond Formulation: Contributions of Nanotechnology for Translation of Anticancer Natural Products into New Drugs

Nature is the largest pharmacy in the world. Doxorubicin (DOX) and paclitaxel (PTX) are two examples of natural-product-derived drugs employed as first-line treatment of various cancer types due to their broad mechanisms of action. These drugs are marketed as conventional and nanotechnology-based formulations, which is quite curious since the research and development (R&D) course of nanoformulations are even more expensive and prone to failure than the conventional ones. Nonetheless, nanosystems are cost-effective and represent both novel and safer dosage forms with fewer side effects due to modification of pharmacokinetic properties and tissue targeting. In addition, nanotechnology-based drugs can contribute to dose modulation, reversion of multidrug resistance, and protection from degradation and early clearance; can influence the mechanism of action; and can enable drug administration by alternative routes and co-encapsulation of multiple active agents for combined chemotherapy. In this review, we discuss the contribution of nanotechnology as an enabling technology taking the clinical use of DOX and PTX as examples. We also present other nanoformulations approved for clinical practice containing different anticancer natural-product-derived drugs.

Next-Generation Anti-Angiogenic Therapies as a Future Prospect for Glioma Immunotherapy; From Bench to Bedside

Glioblastoma (grade IV glioma) is the most aggressive histopathological subtype of glial tumors with inordinate microvascular proliferation as one of its key pathological features. Extensive angiogenesis in the tumor microenvironment supplies oxygen and nutrients to tumoral cells; retains their survival under hypoxic conditions; and induces an immunosuppressive microenvironment. Anti-angiogenesis therapy for high-grade gliomas has long been studied as an adjuvant immunotherapy strategy to overcome tumor growth. In the current review, we discussed the underlying molecular mechanisms contributing to glioblastoma aberrant angiogenesis. Further, we discussed clinical applications of monoclonal antibodies, tyrosine kinase inhibitors, and aptamers as three major subgroups of anti-angiogenic immunotherapeutics and their limitations. Moreover, we reviewed clinical and preclinical applications of small interfering RNAs (siRNAs) as the next-generation anti-angiogenic therapeutics and summarized their potential advantages and limitations. siRNAs may serve as next-generation anti-angiogenic therapeutics for glioma. Additionally, application of nanoparticles as a delivery vehicle could increase their selectivity and lower their off-target effects.

Application of lipid nanovesicle drug delivery system in cancer immunotherapy

Immunotherapy has gradually emerged as the most promising anticancer therapy. In addition to conventional anti-PD-1/PD-L1 therapy, anti-CTLA-4 therapy, CAR-T therapy, etc., immunotherapy can also be induced by stimulating the maturation of immune cells or inhibiting negative immune cells, regulating the tumor immune microenvironment and cancer vaccines. Lipid nanovesicle drug delivery system includes liposomes, cell membrane vesicles, bacterial outer membrane vesicles, extracellular vesicles and hybrid vesicles. Lipid nanovesicles can be used as functional vesicles for cancer immunotherapy, and can also be used as drug carriers to deliver immunotherapy drugs to the tumor site for cancer immunotherapy. Here, we review recent advances in five kinds of lipid nanovesicles in cancer immunotherapy and assess the clinical application prospects of various lipid nanovesicles, hoping to provide valuable information for clinical translation in the future.

Revisiting the outstanding questions in cancer nanomedicine with a future outlook

The field of cancer nanomedicine has been fueled by the expectation of mitigating the inefficiencies and life-threatening side effects of conventional chemotherapy. Nanomedicine proposes to utilize the unique nanoscale properties of nanoparticles to address the most pressing questions in cancer treatment and diagnosis. The approval of nano-based products in the 1990s inspired scientific explorations in this direction. However, despite significant progress in the understanding of nanoscale properties, there are only very few success stories in terms of substantial increase in clinical efficacy and overall patient survival. All existing paradigms such as the concept of enhanced permeability and retention (EPR), the stealth effect and immunocompatibility of nanomedicine have been questioned in recent times. In this review we critically examine impediments posed by biological factors to the clinical success of nanomedicine. We put forth current observations on critical outstanding questions in nanomedicine. We also provide the promising side of cancer nanomedicine as we move forward in nanomedicine research. This would provide a future direction for research in nanomedicine and inspire ongoing investigations.

Towards principled design of cancer nanomedicine to accelerate clinical translation

Nanotechnology in medical applications, especially in oncology as drug delivery systems, has recently shown promising results. However, although these advances have been promising in the pre-clinical stages, the clinical translation of this technology is challenging. To create drug delivery systems with increased treatment efficacy for clinical translation, the physicochemical characteristics of nanoparticles such as size, shape, elasticity (flexibility/rigidity), surface chemistry, and surface charge can be specified to optimize efficiency for a given application. Consequently, interdisciplinary researchers have focused on producing biocompatible materials, production technologies, or new formulations for efficient loading, and high stability. The effects of design parameters can be studied in vitro, in vivo, or using computational models, with the goal of understanding how they affect nanoparticle biophysics and their interactions with cells. The present review summarizes the advances and technologies in the production and design of cancer nanomedicines to achieve clinical translation and commercialization. We also highlight existing challenges and opportunities in the field.

Tailoring the physicochemical properties of nanomaterials for immunomodulation

Immunomodulation is poised to revolutionize the treatment of cancer, autoimmune diseases, and many other inflammation-related disorders. The immune system in these conditions can be either activated or suppressed by nanocarriers loaded with bioactive molecules. Although immunomodulation via these therapeutics has long been recognized, and a broad range of nanocarriers have been designed to accommodate varied usages, less studies have focused on the effects of nanomaterial physicochemical properties on immune responses, especially the immunity altered by nanocarrier materials alone. Conclusions are sometimes seemly inconsistent due to the complexities of nanomaterials and the immune system. An in-depth understanding of the nanocarrier-induced immune responses is essential for clinical applications. In this review, we summarize recent studies of the immune responses influenced by nanomaterial physicochemical properties with an emphasis on the intrinsic features of nanomaterials that modulate the innate and adaptive immunities. We then provide our perspectives on the design of nanomaterials for immunomodulation.

Nanoliposomes as drug delivery systems: safety concerns

The review highlights the safety issues of drug delivery systems based on liposomes. Due to their small sizes (about 80-120 nm, sometimes even smaller), phospholipid nanoparticles interact intensively with living systems during parenteral administration. This interaction significantly affects both their transport role and safety; therefore, special attention is paid to these issues. The review summarises the data on the basic factors affecting the safety of nanoliposomes: composition, size, surface charge, stability, the release of an incorporated drug, penetration into tissues, interaction with the complement system. Attention is paid to the authors' own research of unique phospholipid nanoparticles with a diameter of 20-30 nm. The influence of technological processes of nanoliposome production on their properties is considered. The article also discusses the modern safety assessment criteria contained in the preliminary regulatory documents of the manufacturing countries for new nanoliposome-based drugs being developed or used in the clinic.

Integrin-Targeted, Short Interfering RNA Nanocomplexes for Neuroblastoma Tumor-Specific Delivery Achieve MYCN Silencing with Improved Survival

The authors aim to develop siRNA therapeutics for cancer that can be administered systemically to target tumors and retard their growth. The efficacy of systemic delivery of siRNA to tumors with nanoparticles based on lipids or polymers is often compromised by their rapid clearance from the circulation by the liver. Here, multifunctional cationic and anionic siRNA nanoparticle formulations are described, termed receptor-targeted nanocomplexes (RTNs), that comprise peptides for siRNA packaging into nanoparticles and receptor-mediated cell uptake, together with lipids that confer nanoparticles with stealth properties to enhance stability in the circulation, and fusogenic properties to enhance endosomal release within the cell. Intravenous administration of RTNs in mice leads to predominant accumulation in xenograft tumors, with very little detected in the liver, lung, or spleen. Although non-targeted RTNs also enter the tumor, cell uptake appears to be RGD peptide-dependent indicating integrin-mediated uptake. RTNs with siRNA against MYCN (a member of the Myc family of transcription factors) in mice with MYCN-amplified neuroblastoma tumors show significant retardation of xenograft tumor growth and enhanced survival. This study shows that RTN formulations can achieve specific tumor-targeting, with minimal clearance by the liver and so enable delivery of tumor-targeted siRNA therapeutics.

Liposomes: Structure, Biomedical Applications, and Stability Parameters With Emphasis on Cholesterol

Liposomes are essentially a subtype of nanoparticles comprising a hydrophobic tail and a hydrophilic head constituting a phospholipid membrane. The spherical or multilayered spherical structures of liposomes are highly rich in lipid contents with numerous criteria for their classification, including structural features, structural parameters, and size, synthesis methods, preparation, and drug loading. Despite various liposomal applications, such as drug, vaccine/gene delivery, biosensors fabrication, diagnosis, and food products applications, their use encounters many limitations due to physico-chemical instability as their stability is vigorously affected by the constituting ingredients wherein cholesterol performs a vital role in the stability of the liposomal membrane. It has well established that cholesterol exerts its impact by controlling fluidity, permeability, membrane strength, elasticity and stiffness, transition temperature (Tm), drug retention, phospholipid packing, and plasma stability. Although the undetermined optimum amount of cholesterol for preparing a stable and controlled release vehicle has been the downside, but researchers are still focused on cholesterol as a promising material for the stability of liposomes necessitating explanation for the stability promotion of liposomes. Herein, the prior art pertaining to the liposomal appliances, especially for drug delivery in cancer therapy, and their stability emphasizing the roles of cholesterol.

Strategies and applications of covalent organic frameworks as promising nanoplatforms in cancer therapy

Cancer nanomedicine is the best option to face the limits of conventional chemotherapy and phototherapy methods, and thus the intensive quest for new nanomaterials to improve therapeutic efficacy and safety is still underway. Owing to their low density, well-defined structures, large surface area, finely tunable pore size, and metal ion free features, covalent organic frameworks (COFs) have been extensively studied in many research fields. The recent great interest in nanoscale COFs to improve the properties of bulk COFs has led to broadening of their applicability in the biomedical field, such as nanocarriers with an outstanding loading capacity and efficient delivery of therapeutic agents, smart theranostic nanoplatforms with excellent stability, high ROS generation, light-to-heat conversion capabilities, and different response and diagnostic characteristics. The COFs and related nanoplatforms with a wide variety of designability and functionalization have opened up a new avenue for exciting opportunities in cancer therapy. Herein we review the state-of-the-art technical and scientific developments in this emerging field, focusing on the overall progress addressed so far in building versatile COF-based nanoplatforms to enhance chemotherapy, photodynamic/photothermal therapy, and combination. Future perspectives for achieving the synergistic effect of cancer elimination and clinical translation are further discussed to motivate future contributions and explore new possibilities.

Preclinical autophagy modulatory nanomedicines: big challenges, slow advances

INTRODUCTION

Autophagy is a critical housekeeping pathway to remove toxic protein aggregates, damaged organelles, providing cells with bioenergetic substrates needed to survive under adverse conditions. Since altered autophagy is associated with diverse diseases, its pharmacological modulation is considered of therapeutic interest. Nanomedicines may reduce the toxicity and improve the activity of toxic autophagy modulatory drugs (amd).

AREAS COVERED

The status of the most relevant anti-tumor, anti-inflammatory, and anti-infectious treatments mediated by autophagy modulatory nanomedicines (amN) published in the last 5 years is discussed.

EXPERT OPINION

Antitumor and anti-inflammatory treatments may be improved by administering amN for selective, massive, and targeted delivery of amd to diseased tissues. The use of amN as antimicrobial agent remains almost underexploited. Assessing the effect of amN on the complex autophagy machinery operating under different basal diseases, however, is not a trivial task. Besides structural reproducibility, nanomedicines must grant higher efficiency, and lower adverse effects than conventional medication. Simplicity of design, carefully chosen (scalable) preparation techniques, and rigorous monitoring of preclinical efficacy and nanotoxicity will improve the chances of clinical success. Currently, available data are not sufficient to envisage a fast-succeeding translation. Application of quality by design criteria would help to reach such milestones.

Liposomes with Caffeic Acid: Morphological and Structural Characterisation, Their Properties and Stability in Time

Medical and pharmaceutical research has shown that liposomes are very efficient in transporting drugs to targets. In this study, we prepared six liposome formulas, three in which we entrapped caffeic acid (CA), and three with only phospholipids and without CA. Determination of entrapment efficiency (EE) showed that regardless of the phospholipids used, the percentage of CA entrapment was up to 76%. The characterization of the liposomes was performed using Dynamic Light Scattering (DLS), Atomic Force Microscopy (AFM), zeta potential and polydispersity and showed that about 75–99% of the liposomes had dimensions between 40 ± 0.55–500 ± 1.45 nm. The size and zeta potential of liposomes were influenced by the type of phospholipid used to obtain them. CA release from liposomes was performed using a six-cell Franz diffusion system, and it was observed that the release of entrapped CA occurs gradually, the highest amount occurring in the first eight hours (over 80%), after which the release is much reduced. Additionally, the time stability of the obtained liposomes was analysed using univariate and multivariate statistical analysis. Therefore, liposomes offer great potential in CA entrapment.

Lipid nanovesicles for biomedical applications: 'What is in a name'?

Vesicles, generally defined as self-assembled structures formed by single or multiple concentric bilayers that surround an aqueous core, have been widely used for biomedical applications. They can either occur naturally (e.g. exosomes) or be produced artificially and range from the micrometric scale to the nanoscale. One the most well-known vesicle is the liposome, largely employed as a drug delivery nanocarrier. Liposomes have been modified along the years to improve physicochemical and biological features, resulting in long-circulating, ligand-targeted and stimuli-responsive liposomes, among others. In this process, new nomenclatures were reported in an extensive literature. In many instances, the new names suggest the emergence of a new nanocarrier, which have caused confusion as to whether the vesicles are indeed new entities or could simply be considered modified liposomes. Herein, we discussed the extensive nomenclature of vesicles based on the suffix "some" that are employed for drug delivery and composed of various types and proportions of lipids and others amphiphilic compounds. New names have most often been selected based on changes of vesicle lipid composition, but the payload, structural complexity (e.g. multicompartment) and new/improved proprieties (e.g. elasticity) have also inspired new vesicle names. Based on this discussion, we suggested a rational classification for vesicles.

Recent advances in drug delivery applications of cubosomes, hexosomes, and solid lipid nanoparticles

The use of lipid nanocarriers for drug delivery applications is an active research area, and a great interest has particularly been shown in the past two decades. Among different lipid nanocarriers, ISAsomes (Internally self-assembled somes or particles), including cubosomes and hexosomes, and solid lipid nanoparticles (SLNs) have unique structural features, making them attractive as nanocarriers for drug delivery. In this contribution, we focus exclusively on recent advances in formation and characterization of ISAsomes, mainly cubosomes and hexosomes, and their use as versatile nanocarriers for different drug delivery applications. Additionally, the advantages of SLNs and their application in oral and pulmonary drug delivery are discussed with focus on the biological fates of these lipid nanocarriers in vivo. Despite the demonstrated advantages in in vitro and in vivo evaluations including preclinical studies, further investigations on improved understanding of the interactions of these nanoparticles with biological fluids and tissues of the target sites is necessary for efficient designing of drug nanocarriers and exploring potential clinical applications.

Therapeutic efficacy and cardioprotection of nucleolin-targeted doxorubicin-loaded ultrasound nanobubbles in treating triple-negative breast cancer

Targeted lipid nanobubbles as theranostic ultrasound molecular probes with both targeted contrast-enhanced ultrasound molecular imaging and synergistic treatment capabilities are expected to overcome severe challenges in the diagnosis and treatment of refractory triple-negative breast cancer (TNBC). In this study, AS1411 aptamer-functionalised nucleolin-targeted doxorubicin-loaded lipid nanobubbles (AS1411-DOX-NBs) were constructed, and their physicochemical properties as well as anti-tumour and cardioprotective efficacies were systematically tested and evaluated. The results showed that AS1411-DOX-NBs can carry and maintain the physicochemical and pharmacodynamic properties of doxorubicin (DOX) and show stronger tumour cell-killing abilityin vitroby increasing the active uptake of drugs. AS1411-DOX-NBs also significantly inhibited the growth of TNBC xenografts while maintaining the weight and health of the mice. Echocardiography and pathological examination further confirmed that AS1411-DOX-NBs effectively caused tumour tissue apoptosis and necrosis while reducing DOX-induced cardiotoxicity. The AS1411-DOX-NBs constructed in this study enable both targeted contrast-enhanced ultrasound molecular imaging and synergistic therapeutic efficacy and can be used as safe and efficient theranostic ultrasound molecular probes for the diagnosis and treatment of TNBC.

Levobupivacaine-Loaded Liposome Associated with Thermogel for Prolonged Analgesia

Pain is a phenomenon present in the majority of the population, affecting, among others, the elderly, overweight people, and especially recently operated patients, analgesia being necessary. In the specific case of relief of postoperative pain, different kinds of anesthetics are being used, among them bupivacaine, a widely used drug which promotes long-lasting analgesic effects. However, cardiotoxicity and neurotoxicity are related to its repetitive use. To overcome these shortcomings, Novabupi® (a racemic mixture) was developed and is marketed as an injectable solution. This formulation contains an enantiomeric excess of the levogyre isomer, which has reduced toxicity effects. Seeking to rationalize its use by extending the duration of effect and reducing the number of applications, the objectives of this work were to develop and evaluate liposomes containing Novabupi (LBPV), followed by incorporation into thermogel. Liposomes were prepared using the lipid hydration method, followed by size reduction using sonication, and the developed formulations were characterized by hydrodynamic diameter, polydispersity index (PDI), surface zeta potential, and encapsulation efficiency. The selected optimal liposomal formulation was successfully incorporated into a thermogel without loss of thermoresponsive properties, being suitable for administration as a subcutaneous injection. In the ex vivo permeation studies with fresh rodent skin, the thermogel with liposomes loaded with 0.5% LBPV (T-gel formulation 3) showed higher permeation rates compared to the starting formulation, thermogel with 0.5% LBPV (T-Gel 1), which will probably translate into better therapeutic benefits for treatment of postoperative analgesia, especially with regard to the number of doses applied.

pH-responsive polymersome-mediated delivery of doxorubicin into tumor sites enhances the therapeutic efficacy and reduces cardiotoxic effects

The delivery of therapeutics into sites of action by using cargo-delivery platforms potentially minimizes their premature degradation and fast clearance from the bloodstream. Additionally, drug-loaded stimuli-responsive supramolecular assemblies can be produced to respond to the inherent features of tumor microenvironments, such as extracellular acidosis. We report in this framework the use of pH-responsive polymersomes (PSs) manufactured using poly([N-(2-hydroxypropyl)] methacrylamide)₃₅-b-poly[2-(diisopropylamino)ethyl methacrylate]₇₅ as the building unit (PHPMA₃₅-b-PDPA₇₅). The self-assemblies were produced with desired size towards long circulation time and tumor accumulation (hydrodynamic diameter - D_H ~ 100 nm), and they could be successfully loaded with 10% w/w DOX (doxorubicin), while maintaining colloidal stability. The DOX loaded amount is presumably mainly burst-released at the acidic microenvironment of tumors thanks to the pH-switchable property of PDPA (pKa ~ 6.8), while reduced drug leakage has been monitored in pH 7.4. Compared to the administration of free DOX, the drug-loaded supramolecular structures greatly enhanced the therapeutic efficacy with effective growth inhibition of EL4 lymphoma tumor model and 100% survival rate in female C57BL/6 black mice over 40 days. The approach also led to reduced cardiotoxic effect. These features highlight the potential application of such nanotechnology-based treatment in a variety of cancer therapies where low local pH is commonly found, and emphasize PHPMA-based nanomedicines as an alternative to PEGylated formulations.

Advances in microfluidic synthesis and coupling with synchrotron SAXS for continuous production and real-time structural characterization of nano-self-assemblies

Microfluidic platforms have become highly attractive tools for synthesis of nanoparticles, including lipid nano-self-assemblies, owing to unique features and at least three important aspects inherent to miniaturized micro-devices. Firstly, the fluids flow under controlled conditions in the microchannels, providing well-defined flow profiles and shorter diffusion lengths that play important roles in enhancing the continuous production of lipid and polymer nanoparticles with relatively narrow size distributions. Secondly, various geometries adapted to microfluidic device designs can be utilized for enhancing the colloidal stability of nanoparticles and improving their drug loading. Thirdly, microfluidic devices are usually compatible with in situ characterization methods for real-time monitoring of processes occurring inside the microchannels. This is unlike conventional nanoparticle synthesis methods, where a final solution or withdrawn aliquots are separately analysed. These features inherent to microfluidic devices provide a tool-set allowing not only precise nanoparticle size control, but also real-time analyses for process optimization. In this review, we focus on recent advances and developments in the use of microfluidic devices for synthesis of lipid nanoparticles. We present different designs based on hydrodynamic flow focusing, droplet-based methods and controlled microvortices, and discuss integration of microfluidic platforms with synchrotron small-angle X ray scattering (SAXS) for in situ structural characterization of lipid nano-self-assemblies under continuous flow conditions, along with major challenges and future directions in this research area.

Enhanced intraperitoneal delivery of charged, aerosolized curcumin nanoparticles by electrostatic precipitation

Aims: To investigate the potential of curcumin-loaded polylactic-co-glycolic acid nanoparticles (CUR-PLGA-NPs), alone and with electrostatic precipitation, for improving tissue uptake during pressurized intraperitoneal aerosol chemotherapy (PIPAC). Methods: Positively and negatively charged CUR-PLGA-NPs were delivered as PIPAC into inverted bovine urinary bladders ex vivo. The experiment was repeated with the additional use of electrostatic precipitation pressurized intraperitoneal aerosol chemotherapy (electrostatic PIPAC). Results: Positively charged CUR-PLGA-NPs increased depth of tissue penetration by 81.5% and tissue concentration by 80%. Electrostatic precipitation further improved the uptake of positively charged CUR-PLGA-NPs by 41.8%. Conclusion: The combination of positive charge and electrostatic precipitation have significant potential to improve tissue uptake of nanoparticles during intraperitoneal chemotherapy.

Co-Delivery of Hispolon and Doxorubicin Liposomes Improves Efficacy Against Melanoma Cells

Hispolon is a small molecular weight polyphenol that has antioxidant, anti-inflammatory, and anti-proliferative activities. Our recent study has demonstrated hispolon as a potent apoptosis inducer in melanoma cell lines. Doxorubicin is a broad spectrum first-line treatment for various kinds of cancers. In this study, co-delivery of doxorubicin and hispolon using a liposomal system in B16BL6 melanoma cell lines for synergistic cytotoxic effects was investigated. Liposomes were prepared using a lipid film hydration method and loaded with doxorubicin or hispolon. The formulations were characterized for particle size distribution, release profile, and encapsulation efficiency (EE). In addition, in vitro cytotoxicity, in vitro cell apoptosis, and cellular uptake were evaluated. Liposomes exhibited small particle size (mean diameter ~ 100 nm) and narrow size distribution (polydispersity index (< 0.2) and high drug EE% (> 90%). The release from liposomes showed slower release compared to free drug solution as an additional time required for the release of drug from the liposome lipid bilayer. Liposome loaded with doxorubicin or hispolon exhibited significantly higher cytotoxicity against B16BL6 melanoma cells as compared to doxorubicin solution or hispolon solution. Likewise, co-delivery of hispolon and doxorubicin liposomes showed two-fold and three-fold higher cytotoxicity, as compared to hispolon liposomes or doxorubicin liposomes, respectively. In addition, co-delivery of doxorubicin and hispolon in liposomes enhanced apoptosis more than the individual drugs in the liposome formulation. In conclusion, the co-delivery of hispolon and doxorubicin could be a promising therapeutic approach to improve clinical outcomes against melanoma.

Active Transportation of Liposome Enhances Tumor Accumulation, Penetration, and Therapeutic Efficacy

Liposomes are the first and mostly explored nanocarriers for cancer drug delivery, which have shown great promise in clinical applications, but their limited accumulation and penetration into the tumor interstitial space, significantly reduce the therapeutic efficacy. Here, a γ-glutamyltranspeptidase (GGT)-triggered charge-switchable approach is reported that can trigger the fast endocytosis and transcytosis of the liposome in tumor microenvironments to overcome the harsh biological barriers in tumor tissues. The active transporting liposomal nanocarrier (GCSDL) is prepared by surface modification with a glutathione (GSH) moiety and encapsulated with doxorubicin (DOX). When the GCSDL contacts with tumor vascular endothelial cells, the overexpressed GGT enzyme on cytomembrane catalyzes the hydrolysis of GSH to generate cationic primary amines. The cationic GCSDL triggers fast caveolae-mediated endocytosis and vesicle-mediated transcytosis, resulting in sequential transcytosis to augment its tumor accumulation and penetration. Along with continual intercellular transportation, GCSDL can release DOX throughout the tumor to induce cancer cell apoptosis, resulting in complete eradication of hepatocellular carcinoma and cessation of pancreatic ductal adenocarcinoma's progression. This study develops an efficient strategy to realize high tumor accumulation and deep penetration for the liposomal drug delivery system via active transcytosis.

Synthesis, self-assembly and anticancer drug encapsulation and delivery properties of cyclodextrin-based giant amphiphiles

Cyclodextrin-calixarene giant amphiphiles that can self-assemble into nanospheres or nanovesicles have the ability to encapsulate the anticancer hydrophobic drugs docetaxel, temozolomide and combretastatin A-4 with encapsulation efficiencies >80% and deliver them to tumoral cells, enhancing their therapeutic efficacy by 1-3 orders of magnitude. These amphiphiles were modified by inserting a disulfide bridge confering them redox responsiveness. Disassembly of the resulting nanocompounds and cargo release was favored by high glutathione levels mimicking those present in the tumor microenvironment. Anticancer drug-loaded nanoformulations inhibited prostate, breast, glioblastoma, colon or cervix cancer cell lines proliferation with IC₅₀ values markedly below those observed for the free drugs. Cell-cycle analysis indicated a similar mechanism of action for drug-loaded nanocompounds and free drugs. The results strongly suggest that the cyclodextrin-calixarene heterodimer prototype is an excellent scaffold for nanoformulations aimed to deliver anticancer drugs with limited bioavailability due to low solubility to tumoral cells, markedly increasing their effectivity.

Safety Considerations of Cancer Nanomedicine-A Key Step toward Translation

The rate of translational effort of nanomedicine requires strategic planning of nanosafety research in order to enable clinical trials and safe use of nanomedicine in patients. Herein, the experiences that have emerged based on the safety data of classic liposomal formulations in the space of oncology are discussed, along with a description of the new challenges that need to be addressed according to the rapid expansion of nanomedicine platform beyond liposomes. It is valuable to consider the combined use of predictive toxicological assessment supported by deliberate investigation on aspects such as absorption, distribution, metabolism, and excretion (ADME) and toxicokinetic profiles, the risk that may be introduced during nanomanufacture, unique nanomaterials properties, and nonobvious nanosafety endpoints, for example. These efforts will allow the generation of investigational new drug-enabling safety data that can be incorporated into a rational infrastructure for regulatory decision-making. Since the safety assessment relates to nanomaterials, the investigation should cover the important physicochemical properties of the material that may lead to hazards when the nanomedicine product is utilized in humans.

A structurally diverse library of glycerol monooleate/oleic acid non-lamellar liquid crystalline nanodispersions stabilized with nonionic methoxypoly(ethylene glycol) (mPEG)-lipids showing variable complement activation properties

Pluronic F127-stabilized non-lamellar liquid crystalline aqueous nanodispersions are promising injectable platforms for drug and contrast agent delivery. These nanodispersions, however, trigger complement activation in the human blood, where the extent of complement activation and opsonization processes may compromise their biological performance and safety. Here, we introduce a broad family of nanodispersions from glycerol monooleate (GMO) and oleic acid (OA) in different weight ratios, and stabilized with a plethora of nonionic methoxypoly(ethylene glycol) (mPEG)-lipids of different PEG chain length and variable lipid moiety (monounsaturated or saturated diglycerides or D-α-tocopheryl succinate). Through an integrated biophysical approach involving dynamic light scattering, synchrotron small-angle scattering, and cryo-transmission electron microscopy, we examine the impact of nonionic mPEG-lipid stabilization on size, internal self-assembled architecture, and gross morphological characteristics of nanodispersions. The results show how the nonionic mPEG-lipid type and concentration, and dependent on GMO/OA weight ratio, can variably modulate the internal architectures of nanoparticles. Assessment of complement profiling from selected nanodispersions with diverse structural heterogeneity further suggests a variable modulatory role for the lipid type of the nonionic mPEG-lipid in the extent of complement activation, which span from no activation to moderate to high levels. We comment on plausible mechanisms driving the observed complement activation variability and discuss the potential utility of these nanodispersions for future development of injectable nanopharmaceuticals.