Magnetoresponsive virus-mimetic nanocapsules with dual heat-triggered sequential-infected multiple drug-delivery approach for combinatorial tumor therapy

Targeting Intracellular Bacteria with Dual Drug-loaded Lactoferrin Nanoparticles

Treatment of microbial infections is becoming daunting because of widespread antimicrobial resistance. The treatment challenge is further exacerbated by the fact that certain infectious bacteria invade and localize within host cells, protecting the bacteria from antimicrobial treatments and the host's immune response. To survive in the intracellular niche, such bacteria deploy surface receptors similar to host cell receptors to sequester iron, an essential nutrient for their virulence, from host iron-binding proteins, in particular lactoferrin and transferrin. In this context, we aimed to target lactoferrin receptors expressed by macrophages and bacteria; as such, we prepared and characterized lactoferrin nanoparticles (Lf-NPs) loaded with a dual drug combination of antimicrobial natural alkaloids, berberine or sanguinarine, with vancomycin or imipenem. We observed increased uptake of drug-loaded Lf-NPs by differentiated THP-1 cells with up to 90% proportion of fluorescent cells, which decreased to about 60% in the presence of free lactoferrin, demonstrating the targeting ability of Lf-NPs. The encapsulated antibiotic drug cocktail efficiently cleared intracellular Staphylococcus aureus (Newman strain) compared to the free drug combinations. However, the encapsulated drugs and the free drugs alike exhibited a bacteriostatic effect against the hard-to-treat Mycobacterium abscessus (smooth variant). In conclusion, the results of this study demonstrate the potential of lactoferrin nanoparticles for the targeted delivery of antibiotic drug cocktails for the treatment of intracellular bacteria.

Virus-inspired strategies for cancer therapy

The intentional use of viruses for cancer therapy dates back over a century. As viruses are inherently immunogenic and naturally optimized delivery vehicles, repurposing viruses for drug delivery, tumor antigen presentation, or selective replication in cancer cells represents a simple and elegant approach to cancer treatment. While early virotherapy was fraught with harsh side effects and low response rates, virus-based therapies have recently seen a resurgence due to newfound abilities to engineer and tune oncolytic viruses, virus-like particles, and virus-mimicking nanoparticles for improved safety and efficacy. However, despite their great potential, very few virus-based therapies have made it through clinical trials. In this review, we present an overview of virus-inspired approaches for cancer therapy, discuss engineering strategies to enhance their mechanisms of action, and highlight their application for overcoming the challenges of traditional cancer therapies.

Role of Doxorubicin on the Loading Efficiency of ICG within Silk Fibroin Nanoparticles

The effective loading or encapsulation of multimodal theranostic agents within a nanocarrier system plays an important role in the clinical development of cancer therapy. In recent years, the silk fibroin protein-based delivery system has been drawing significant attention to be used in nanomedicines due to its biocompatible and biodegradable nature. In this study, silk fibroin nanoparticles (SNPs) have been synthesized by a novel and cost-effective ultrasonic atomizer-based technique for the first time. The fabricated SNPs were coencapsulated by the FDA-approved indocyanine green (ICG) dye and the chemotherapeutic drug doxorubicin (DOX). The synthesized SNPs are spherical, with an average diameter of ∼37 ± 4 nm, and the ICG-DOX-coencapsulated SNPs (ID-SNPs) have a diameter size of ∼47 ± 6 nm. For the first time, here we demonstrate that DOX helps in the higher loading of ICG within the ID-SNPs, which enhances the encapsulation efficiency of ICG by ∼99%. This could be attributed to the interaction of ICG and DOX molecules with the silk fibroin protein, which helps ICG to get loaded more efficiently within these nanoparticles. The overall finding of this study suggests that the ID-SNPs could be utilized for enhanced ICG-complemented multimodal deep-tissue bioimaging and synergistic chemo-photothermal therapy.

Re-engineered imaging agent using biomimetic approaches

Recent progress in biomedical technology, the clinical bioimaging, has a greater impact on the diagnosis, treatment, and prevention of disease, especially by early intervention and precise therapy. Varieties of organic and inorganic materials either in the form of small molecules or nano-sized materials have been engineered as a contrast agent (CA) to enhance image resolution among different tissues for the detection of abnormalities such as cancer and vascular occlusion. Among different innovative imaging agents, contrast agents coupled with biologically derived endogenous platform shows the promising application in the biomedical field, including drug delivery and bioimaging. Strategy using biocomponents such as cells or products of cells as a delivery system predominantly reduces the toxic behavior of its cargo, as these systems reduce non-specific distribution by navigating its cargo toward the targeted location. The hypothesis is that depending on the original biological role of the naïve cell, the contrast agents carried by such a system can provide corresponding natural designated behavior. Therefore, by combining properties of conventional synthetic molecules and nanomaterials with endogenous cell body, new solutions in the field of bioimaging to overcome biological barriers have been offered as innovative bioengineering. In this review, we will discuss the engineering of cell and cell-derived components as a delivery system for various contrast agents to achieve clinically relevant contrast for diagnosis and study underlining mechanism of disease progression. This article is categorized under: Nanotechnology Approaches to Biology > Cells at the Nanoscale Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Exploiting Peptide Self-Assembly for the Development of Minimalistic Viral Mimetics

Viruses are natural supramolecular nanostructures that form spontaneously by molecular self-assembly of complex biomolecules. Peptide self-assembly is a versatile tool that allows mimicking viruses by creating their simplified versions through the design of functional, supramolecular materials with modularity, tunability, and responsiveness to chemical and physical stimuli. The main challenge in the design and fabrication of peptide materials is related to the precise control between the peptide sequence and its resulting supramolecular morphology. We provide an overview of existing sequence patterns employed for the development of spherical and fibrillar peptide assemblies that can act as viral mimetics, offering the opportunity to tackle the challenges of viral infections.

Stimuli-Responsive Iron Oxide Nanotheranostics: A Versatile and Powerful Approach for Cancer Therapy

Recent advancements in unravelling elements of cancer biology involved in disease progression and treatment resistance have highlighted the need for a holistic approach to effectively tackle cancer. Stimuli-responsive nanotheranostics based on iron oxide nanoparticles are an emerging class of versatile nanomedicines with powerful capabilities to "seek, sense, and attack" multiple components of solid tumors. In this work, the rationale for using iron oxide nanoparticles and the basic physical principles that impact their function in biomedical applications are reviewed. Subsequently, recent advances in the integration of iron oxide nanoparticles with various stimulus mechanisms to facilitate the development of stimuli-responsive nanotheranostics for application in cancer therapy are summarized. The integration of an iron oxide core with various surface coating mechanisms results in the generation of hybrid nanoconstructs with capabilities to codeliver a wide variety of highly potent anticancer therapeutics and immune modulators. Finally, emerging future directions and considerations for their clinical translation are touched upon.

Biomedical nanoparticle design: What we can learn from viruses

Viruses are nanomaterials with a number of properties that surpass those of many synthetic nanoparticles (NPs) for biomedical applications. They possess a rigorously ordered structure, come in a variety of shapes, and present unique surface elements, such as spikes. These attributes facilitate propitious biodistribution, the crossing of complex biological barriers and a minutely coordinated interaction with cells. Due to the orchestrated sequence of interactions of their stringently arranged particle corona with cellular surface receptors they effectively identify and infect their host cells with utmost specificity, while evading the immune system at the same time. Furthermore, their efficacy is enhanced by their response to stimuli and the ability to spread from cell to cell. Over the years, great efforts have been made to mimic distinct viral traits to improve biomedical nanomaterial performance. However, a closer look at the literature reveals that no comprehensive evaluation of the benefit of virus-mimetic material design on the targeting efficiency of nanomaterials exists. In this review we, therefore, elucidate the impact that viral properties had on fundamental advances in outfitting nanomaterials with the ability to interact specifically with their target cells. We give a comprehensive overview of the diverse design strategies and identify critical steps on the way to reducing them to practice. More so, we discuss the advantages and future perspectives of a virus-mimetic nanomaterial design and try to elucidate if viral mimicry holds the key for better NP targeting.

Virus-mimetic systems for cancer diagnosis and therapy

Over past decades, various strategies have been developed to enhance the delivery efficiency of therapeutics and imaging agents to tumor tissues. However, the therapeutic outcome of tumors to date have not been significantly improved, which can be partly attributed to the weak targeting ability, fast elimination, and low stability of conventional delivery systems. Viruses are the most efficient agents for gene transfer, serving as a valuable source of inspiration for designing nanoparticle-based delivery systems. Based on the properties of viruses, including well-defined geometry, precise composition, easy modification, stable construction, and specific infection, researchers attempt to design biocompatible delivery vectors by mimicking virus assembly and using the vector system to selectively concentrate drugs or imaging probes in tumors with mitigated toxicity and improved efficacy. In this review, we introduce common viruses features and provide an overview of various virus-mimetic strategies for cancer therapy and diagnosis. The challenges faced by virus-mimetic systems are also discussed. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Bioinspired and Biomimetic Nanotherapies for the Treatment of Infectious Diseases

There are still great challenges for the effective treatment of infectious diseases, although considerable achievement has been made by using antiviral and antimicrobial agents varying from small-molecule drugs, peptides/proteins, to nucleic acids. The nanomedicine approach is emerging as a new strategy capable of overcoming disadvantages of molecular therapeutics and amplifying their anti-infective activities, by localized delivery to infection sites, reducing off-target effects, and/or attenuating resistance development. Nanotechnology, in combination with bioinspired and biomimetic approaches, affords additional functions to nanoparticles derived from synthetic materials. Herein, we aim to provide a state-of-the-art review on recent progress in biomimetic and bioengineered nanotherapies for the treatment of infectious disease. Different biomimetic nanoparticles, derived from viruses, bacteria, and mammalian cells, are first described, with respect to their construction and biophysicochemical properties. Then, the applications of diverse biomimetic nanoparticles in anti-infective therapy are introduced, either by their intrinsic activity or by loading and site-specifically delivering various molecular drugs. Bioinspired and biomimetic nanovaccines for prevention and/or therapy of infectious diseases are also highlighted. At the end, major translation issues and future directions of this field are discussed.

Homing in on an intracellular target for delivery of loaded nanoparticles functionalized with a histone deacetylase inhibitor

Functionalized nanoparticles (NPs) are usually used to enhance cellular penetration for targeted drug delivery that can improve efficacy and reduce side effects. However, it is difficult to exploit intracellular targets for similar delivery applications. Herein we describe the targeted delivery of functionalized NPs by homing in on an intracellular target, histone deacetylases (HDACs). Specifically, a modified poly-lactide-co-glycolideacid (FPLGA) was yielded by conjugation with an HDAC inhibitor. Subsequently, FPLGA was used to prepare functionalized FPLGA NPs. Compared to unmodified NPs, FPLGA NPs were more efficiently uptaken or retained by MCF-7 cells and showed longer retention time intracellular. In vivo fluorescence imaging also revealed that they had a higher accumulation and a slower elimination than unmodified NPs. FPLGA NPs loaded with paclitaxel exhibited superior anticancer efficacy compared with unmodified NPs. These results offer a promising approach for intracellular drug delivery through elevating the concentration of NPs.

Recent progress on nanoparticle-based drug delivery systems for cancer therapy

The development of cancer nanotherapeutics has attracted great interest in the recent decade. Cancer nanotherapeutics have overcome several limitations of conventional therapies, such as nonspecific biodistribution, poor water solubility, and limited bioavailability. Nanoparticles with tuned size and surface characteristics are the key components of nanotherapeutics, and are designed to passively or actively deliver anti-cancer drugs to tumor cells. We provide an overview of nanoparticle-based drug delivery methods and cancer therapies based on tumor-targeting delivery strategies that have been developed in recent years.

Enzyme-coated Janus nanoparticles that selectively bind cell receptors as a function of the concentration of glucose

A method is proposed for controlling the number of nanoparticles bound to cell membranes via RGDS peptide-integrin interactions. It consists of propelling nanoparticles bearing the peptides with enzymes (glucose oxidase), which disrupts biomolecular interactions as a function of the concentration of enzyme substrate (glucose).

A biocompatible and magnetic nanocarrier with a safe UV-initiated docetaxel release and cancer secretion removal properties increases therapeutic potential for skin cancer

Cancer is a leading fatal disease worldwide. To increase its therapeutic efficiency, more effective with less side effect and patient acceptable administration approach is expected. Moreover, modification of tumor microenvironment is proved to be operative recently. In this paper, a nanocarrier named LDEDDS was developed for intelligent tropical administration of skin cancer, along with removal of hydrophobic cancerous secretion to change tumor microenvironment. It was made by coating of amphipathic polymer P(BA-co-HBA) on docetaxel (TXT, a model hydrophobic anticancer drug) loaded Fe₃O₄@ZnO. Results showed that an optimal loading rate of TXT in Fe₃O₄@ZnO was 89.75±0.15%, corresponding to loading capacity of 17.95±2.97% when the mass ratio of Fe₃O₄@ZnO to TXT was 1:20. The LDEDDS had a narrow distribution size of 115.8nm in average and was superparamagnetic. Without UV radiation, it had low TXT release (<7% in 48h) and cytotoxicity (<14% in 96h) to both the normal and carcinoma skin cells. While under a UV with a dose much lower than physiological dose of normal sunlight, LDEDDS released around 60% and 90% of TXT in 1 and 48h. 1h UV treated LDEDDS removed up to 62% of cancer secreted epidermal growth factor (EGF), a model hydrophobic secretion in 96h. Consequently, 1h UV treated LDEDDS inhibited up to 60% of the growth of skin cancer cells in 96h, overriding those effects of the same concentration of TXT in in vitro cellular experiments. This is the first study to change tumor microenvironment by removal of cancerous secretion and is proved to be effective. Along with the superparamagnetic property, which provides potential for concentrating, increasing penetration and internalization into cancerated cells as well as removing from body under an external magnetic field, we predict LDEDDS will have potential applications in clinic skin cancer therapy.

Carrageenan Based Bionanocomposites as Drug Delivery Tool with Special Emphasis on the Influence of Ferromagnetic Nanoparticles

Over the past few years, considerable attention has been focused on carrageenan based bionanocomposites due to their multifaceted properties like biodegradability, biocompatibility, and nontoxicity. Moreover, these composites can be tailored according to the desired purpose by using different nanofillers. The role of ferromagnetic nanoparticles in drug delivery is also discussed here in detail. Moreover, this article also presents a short review of recent research on the different types of the carrageenan based bionanocomposites and applications.

Viruses, Artificial Viruses and Virus-Based Structures for Biomedical Applications

Nanobiomaterials such as virus particles and artificial virus particles offer tremendous opportunities to develop new biomedical applications such as drug- or gene-delivery, imaging and sensing but also improve understanding of biological mechanisms. Recent advances within the field of virus-based systems give insights in how to mimic viral structures and virus assembly processes as well as understanding biodistribution, cell/tissue targeting, controlled and triggered disassembly or release and circulation times. All these factors are of high importance for virus-based functional systems. This review illustrates advances in mimicking and enhancing or controlling these aspects to a high degree toward delivery and imaging applications.

Silane modified upconversion nanoparticles with multifunctions: imaging, therapy and hypoxia detection

Herein, we report a facile route to synthesize silane coated upconversion nanoparticles (UCNPs@silane) with an ultrathin layer (the thickness: 1–2 nm), which not only provides good biocompatibility, but also affords hydrophobic interspace to load organic molecules to realize multifunctions. Besides the function of upconversion imaging of UCNPs, cancer therapy and oxygen level detection can also be realized by the addition of chemotherapy drug, PTX, and oxygen sensitive molecules, Platinum (II) octaethylporphine (PtOEP). In bio-experiments, besides the MTT assays, therapy efficacy of UCNPs@PTX@silane can also be detected with the confocal laser scanning microscopy (CLSM) by staining methods. UCNPs@PtOEP@silane can afford minimally invasive analysis of dissolved oxygen and then respond sensitively to the variance of intracellular oxygen concentration affected by therapeutic UCNPs@PTX@silane.

Magnetic-responsive microparticles with customized porosity for drug delivery

One step engineering of drug-loaded magnetic porous particles for controlled release and targeting.

Targeted Mesoporous Iron Oxide Nanoparticles-Encapsulated Perfluorohexane and a Hydrophobic Drug for Deep Tumor Penetration and Therapy

A magneto-responsive energy/drug carrier that enhances deep tumor penetration with a porous nano-composite is constructed by using a tumor-targeted lactoferrin (Lf) bio-gate as a cap on mesoporous iron oxide nanoparticles (MIONs). With a large payload of a gas-generated molecule, perfluorohexane (PFH), and a hydrophobic anti-cancer drug, paclitaxel (PTX), Lf-MIONs can simultaneously perform bursting gas generation and on-demand drug release upon high-frequency magnetic field (MF) exposure. Biocompatible PFH was chosen and encapsulated in MIONs due to its favorable phase transition temperature (56 °C) and its hydrophobicity. After a short-duration MF treatment induces heat generation, the local pressure increase via the gasifying of the PFH embedded in MION can substantially rupture the three-dimensional tumor spheroids in vitro as well as enhance drug and carrier penetration. As the MF treatment duration increases, Lf-MIONs entering the tumor spheroids provide an intense heat and burst-like drug release, leading to superior drug delivery and deep tumor thermo-chemo-therapy. With their high efficiency for targeting tumors, Lf-MIONs/PTX-PFH suppressed subcutaneous tumors in 16 days after a single MF exposure. This work presents the first study of using MF-induced PFH gasification as a deep tumor-penetrating agent for drug delivery.

Micellar carriers for the delivery of multiple therapeutic agents

Multi-drug therapy is described as a simultaneous or sequential administration of two or more drugs with similar or different mechanisms of action and is recognized as a more efficient solution to combat successfully, various ailments. Polymeric micelles (PMs) are self-assemblies of block copolymers providing numerous opportunities for drug delivery. To date various micellar formulations were studied for delivery of drugs, nutraceuticals and genes; a few of them are in clinical trials. It was observed that there is an immense need for the development of PMs embedding multiple therapeutic agents to combat various ailments, including cancers, HIV/AIDS, malaria, multiple sclerosis, hypertension, infectious diseases, cardiovascular and metabolic diseases, immune disorders and many psychiatric disorders. Several combinations of drug-drug, drug-nutraceutical, drug-gene and drug-siRNA explored to date are detailed in this review, with a special emphasis on their potential and future perspectives. A summary of various preparation methods, characterization techniques and applications of PMs are also provided. This review presents a holistic approach on multi-drug delivery using micellar carriers and emphasizes on the development of therapeutic hybrids embedding novel combinations for safer and effective therapy.

Biomimetic stem cell membrane-camouflaged iron oxide nanoparticles for theranostic applications

In this study, for the first time, stem cell membrane (STM)-camouflaged superparamagnetic iron oxide nanoparticles (SPIO NPs) were prepared and investigated for potential theranostic applications.