Inhibition of Metastatic Tumor Growth and Metastasis via Targeting Metastatic Breast Cancer by Chlorotoxin-Modified Liposomes

Recent Advances in Biomimetic Nanocarrier-Based Photothermal Therapy for Cancer Treatment

Nanomedicine presents innovative solutions for cancer treatment, including photothermal therapy (PTT). PTT centers on the design of photoactivatable nanoparticles capable of absorbing non-toxic near-infrared light, generating heat within target cells to induce cell death. The successful transition from benchside to bedside application of PTT critically depends on the core properties of nanoparticles responsible for converting light into heat and the surface properties for precise cell-specific targeting. Precisely targeting the intended cells remains a primary challenge in PTT. In recent years, a groundbreaking approach has emerged to address this challenge by functionalizing nanocarriers and enhancing cell targeting. This strategy involves the creation of biomimetic nanoparticles that combine desired biocompatibility properties with the immune evasion mechanisms of natural materials. This review comprehensively outlines various strategies for designing biomimetic photoactivatable nanocarriers for PTT, with a primary focus on its application in cancer therapy. Additionally, we shed light on the hurdles involved in translating PTT from research to clinical practice, along with an overview of current clinical applications.

Neurotoxin-Derived Optical Probes for Biological and Medical Imaging

The superb specificity and potency of biological toxins targeting various ion channels and receptors are of major interest for the delivery of therapeutics to distinct cell types and subcellular compartments. Fused with reporter proteins or labelled with fluorophores and nanocomposites, animal toxins and their detoxified variants also offer expanding opportunities for visualisation of a range of molecular processes and functions in preclinical models, as well as clinical studies. This article presents state-of-the-art optical probes derived from neurotoxins targeting ion channels, with discussions of their applications in basic and translational biomedical research. It describes the design and production of probes and reviews their applications with advantages and limitations, with prospects for future improvements. Given the advances in imaging tools and expanding research areas benefiting from the use of optical probes, described here resources should assist the discovery process and facilitate high-precision interrogation and therapeutic interventions.

Diagnostic and Therapeutic Approaches for Glioblastoma and Neuroblastoma Cancers Using Chlorotoxin Nanoparticles

Glioblastoma multiforme (GB) and high-risk neuroblastoma (NB) are known to have poor therapeutic outcomes. As for most cancers, chemotherapy and radiotherapy are the current mainstay treatments for GB and NB. However, the known limitations of systemic toxicity, drug resistance, poor targeted delivery, and inability to access the blood-brain barrier (BBB), make these treatments less satisfactory. Other treatment options have been investigated in many studies in the literature, especially nutraceutical and naturopathic products, most of which have also been reported to be poorly effective against these cancer types. This necessitates the development of treatment strategies with the potential to cross the BBB and specifically target cancer cells. Compounds that target the endopeptidase, matrix metalloproteinase 2 (MMP-2), have been reported to offer therapeutic insights for GB and NB since MMP-2 is known to be over-expressed in these cancers and plays significant roles in such physiological processes as angiogenesis, metastasis, and cellular invasion. Chlorotoxin (CTX) is a promising 36-amino acid peptide isolated from the venom of the deathstalker scorpion, Leiurus quinquestriatus, demonstrating high selectivity and binding affinity to a broad-spectrum of cancers, especially GB and NB through specific molecular targets, including MMP-2. The favorable characteristics of nanoparticles (NPs) such as their small sizes, large surface area for active targeting, BBB permeability, etc. make CTX-functionalized NPs (CTX-NPs) promising diagnostic and therapeutic applications for addressing the many challenges associated with these cancers. CTX-NPs may function by improving diffusion through the BBB, enabling increased localization of chemotherapeutic and genotherapeutic drugs to diseased cells specifically, enhancing imaging modalities such as magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT), optical imaging techniques, image-guided surgery, as well as improving the sensitization of radio-resistant cells to radiotherapy treatment. This review discusses the characteristics of GB and NB cancers, related treatment challenges as well as the potential of CTX and its functionalized NP formulations as targeting systems for diagnostic, therapeutic, and theranostic purposes. It also provides insights into the potential mechanisms through which CTX crosses the BBB to bind cancer cells and provides suggestions for the development and application of novel CTX-based formulations for the diagnosis and treatment of GB and NB in the future.

Functionalized liposomes for targeted breast cancer drug delivery

Despite the exceptional progress in breast cancer pathogenesis, prognosis, diagnosis, and treatment strategies, it remains a prominent cause of female mortality worldwide. Additionally, although chemotherapies are effective, they are associated with critical limitations, most notably their lack of specificity resulting in systemic toxicity and the eventual development of multi-drug resistance (MDR) cancer cells. Liposomes have proven to be an invaluable drug delivery system but of the multitudes of liposomal systems developed every year only a few have been approved for clinical use, none of which employ active targeting. In this review, we summarize the most recent strategies in development for actively targeted liposomal drug delivery systems for surface, transmembrane and internal cell receptors, enzymes, direct cell targeting and dual-targeting of breast cancer and breast cancer-associated cells, e.g., cancer stem cells, cells associated with the tumor microenvironment, etc.

Peptides with Diverse Functions from Scorpion Venom: A Great Opportunity for the Treatment of a Wide Variety of Diseases

Toxicology Research Center, Medical Basic Sciences Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

The venom glands are a rich source of biologically important peptides with pharmaceutical properties. Scorpion venoms have been identified as a reservoir for components that might be considered as great candidates for drug development. Pharmacological properties of the venom compounds have been confirmed in the treatment of different disorders. Ion channel blockers and AMPs are the main groups of scorpion venom components. Despite the existence of several studies about scorpion peptides, there are still valuable components to be discovered. Additionally, owing to the improvement of proteomics and transcriptomics, the number of peptide drugs is steadily increasing, which reflects the importance of these medications. This review evaluates available literatures on some important scorpion venom peptides with pharmaceutical activities. Given that the last three years have been dominated by the COVID-19 from the medical/pharmaceutical perspective, scorpion compounds with the potential against the coronavirus 2 (SARS-CoV-2) are discussed in this review.

Bioactive peptides from scorpion venoms: therapeutic scaffolds and pharmacological tools

Evolution and natural selection have endowed animal venoms, including scorpion venoms, with a wide range of pharmacological properties. Consequently, scorpions, their venoms, and/or their body parts have been used since time immemorial in traditional medicines, especially in Africa and Asia. With respect to their pharmacological potential, bioactive peptides from scorpion venoms have become an important source of scientific research. With the rapid increase in the characterization of various components from scorpion venoms, a large number of peptides are identified with an aim of combating a myriad of emerging global health problems. Moreover, some scorpion venom-derived peptides have been established as potential scaffolds helpful for drug development. In this review, we summarize the promising scorpion venoms-derived peptides as drug candidates. Accordingly, we highlight the data and knowledge needed for continuous characterization and development of additional natural peptides from scorpion venoms, as potential drugs that can treat related diseases.

Challenges and emerging strategies for next generation liposomal based drug delivery: An account of the breast cancer conundrum

The global cancer burden is witnessing an upsurge with breast cancer surpassing other cancers worldwide. Furthermore, an escalation in the breast cancer caseload is also expected in the coming years. The conventional therapeutic regimens practiced routinely are associated with many drawbacks to which nanotechnological interventions offer a great advantage. But how eminent could liposomes and their advantages be in superseding these existing therapeutic modalities? A solution is reflected in this review that draws attention to a decade-long journey embarked upon by researchers in this wake. This text is a comprehensive discussion of liposomes, the front runners of the drug delivery systems, and their active and passive targeting approaches for breast cancer management. Active targeting has been studied over the decade by many receptors overexpressed on the breast cancer cells and passive targeting with many drug combinations. The results converge on the fact that the actively targeted formulations exhibit a superior efficacy over their non-targeted counterparts and the all liposomal formulations are efficacious over the free drugs. This undoubtedly underlines the dominion of liposomal formulations over conventional chemotherapy. These investigations have led to the development of different liposomal formulations with active and passive targeting capacities that could be explored in depth. Acknowledging and getting a deeper insight into the liposomal evolution through time also unveiled many imperfections and unchartered territories that can be explored to deliver dexterous liposomal formulations against breast cancer and more in the clinical trial pipeline.

Chlorotoxin and Lung Cancer: A Targeting Perspective for Drug Delivery

In the generational evolution of nano-based drug delivery carriers, active targeting has been a major milestone for improved and selective drug accumulation in tissues and cell types beyond the existing passive targeting capabilities. Among the various active targeting moieties, chlorotoxin, a peptide extracted from scorpions, demonstrated promising tumor cell accumulation and selection. With lung cancer being among the leading diagnoses of cancer-related deaths in both men and women, novel therapeutic methodologies utilizing nanotechnology for drug delivery emerged. Given chlorotoxin's promising biological activity, we explore its potential against lung cancer and its utilization for active targeting against this cancer's tumor cells. Our analysis indicates that despite the extensive chlorotoxin's research against glioblastoma, lung cancer research with the molecule has been limited, despite some promising early results.

Antitumoral potential of Chartergellus-CP1 peptide from Chartergellus communis wasp venom in two different breast cancer cell lines (HR+ and triple-negative)

Breast cancer represents the most incident cancer in women. Surgery, chemotherapy, radiation therapy, and hormone therapy remain the main treatment for this type of cancer. However, increasing resistance to anti-cancer drugs through poor response for some types of breast cancer to treatments highlights the need to develop new therapeutic agents to fight the disease. In this study, we evaluated the anti-tumor potential of the Chartergellus-CP1 peptide isolated from the wasp venom of Chartergellus communis in human breast cancer cell lines MCF-7 (HR+) and MDA-MB-231 (triple-negative). Cells viability, morphology, cell cycle dynamics, reactive oxygen species (ROS) production, and apoptosis were assessed for both cell lines after exposure to Chartergellus-CP1 during 24 and 48h. The results showed that Chartergellus-CP1 led to a significant increase of cells in the S phase in addition to a high generation of ROS (being more evident in the MCF-7 cell line) associated with apoptotic cell death. This work demonstrates, for the first time, the cytotoxic effects of Chatergellus-CP1 on human breast cancer cell lines including cell cycle profile, oxidative stress generation, and cell death mechanisms.

Current understandings and clinical translation of nanomedicines for breast cancer therapy

Breast cancer is one of the most frequently diagnosed cancers that is threatening women's life. Current clinical treatment regimens for breast cancer often involve neoadjuvant and adjuvant systemic therapies, which somewhat are associated with unfavorable features. Also, the heterogeneous nature of breast cancers requires precision medicine that cannot be fulfilled by a single type of systemically administered drug. Taking advantage of the nanocarriers, nanomedicines emerge as promising therapeutic agents for breast cancer that could resolve the defects of drugs and achieve precise drug delivery to almost all sites of primary and metastatic breast tumors (e.g. tumor vasculature, tumor stroma components, breast cancer cells, and some immune cells). Seven nanomedicines as represented by Doxil® have been approved for breast cancer clinical treatment so far. More nanomedicines including both non-targeting and active targeting nanomedicines are being evaluated in the clinical trials. However, we have to realize that the translation of nanomedicines, particularly the active targeting nanomedicines is not as successful as people have expected. This review provides a comprehensive landscape of the nanomedicines for breast cancer treatment, from laboratory investigations to clinical applications. We also highlight the key advances in the understanding of the biological fate and the targeting strategies of breast cancer nanomedicine and the implications to clinical translation.

Tumor-targeted Drug Delivery by Nanocomposites

BACKGROUND

Tumor-targeted delivery by nanoparticles is a great achievement towards the use of highly effective drug at very low doses. The conventional development of tumor-targeted delivery by nanoparticles is based on enhanced permeability and retention (EPR) effect and endocytosis based on receptor-mediated are very demanding due to the biological and natural complications of tumors as well as the restrictions on the design of the accurate nanoparticle delivery systems.

METHODS

Different tumor environment stimuli are responsible for triggered multistage drug delivery systems (MSDDS) for tumor therapy and imaging. Physicochemical properties, such as size, hydrophobicity and potential transform by MSDDS because of the physiological blood circulation different, intracellular tumor environment. This system accomplishes tumor penetration, cellular uptake improved, discharge of drugs on accurate time, and endosomal discharge.

RESULTS

Maximum drug delivery by MSDDS mechanism to target therapeutic cells and also tumor tissues and sub cellular organism. Poorly soluble compounds and bioavailability issues have been faced by pharmaceutical industries, which are resolved by nanoparticle formulation.

CONCLUSION

In our review, we illustrate different types of triggered moods and stimuli of the tumor environment, which help in smart multistage drug delivery systems by nanoparticles, basically a multi-stimuli sensitive delivery system, and elaborate their function, effects, and diagnosis.

Shape switching of CaCO3-templated nanorods into stiffness-adjustable nanocapsules to promote efficient drug delivery

Geometry and mechanical property have emerged as important parameters in designing nanocarriers, in addition to their size, surface charge, and hydrophilicity. However, inconsistent and even contradictory demands regarding the shape and stiffness of nanoparticles have been noted in blood circulation, tumor accumulation, and tumor cell internalization. Herein, CaCO₃ nanorods (NRs) with an aspect ratio of around 2.4 are assembled with hyaluronic acid (HA) hydrogel layers to prepare CaCO₃@HA NRs. The rod geometry enables lower recognition by macrophages and higher extravasation into tumor tissues than the spherical counterpart. In response to the slightly acidic tumor matrix, the acid-labile removal of CaCO₃ templates achieves shape switching into spherical HA nanocapsules (NCs). The shape switchable CaCO₃@HA NRs show significantly higher uptake and cytotoxicities to 4T1 cells than CaCO₃-Si@HA NRs with silica layers on CaCO₃ cores to inhibit shape switching. In addition, HA NCs with 2 - 8 layers of HA hydrogels exhibit stiffness from 1.85 to 12.3 N/m, and the assembly of 4 layers shows 2- to 3-fold higher cellular uptake than those of other NCs. The shape shift satisfies long-term blood circulation of NRs, and the resulting stiffness-adjustable NCs promote tissue infiltration and intracellular accommodation, resulting in a 4-fold higher drug accumulation in tumors. The CaCO₃@HA NR treatment significantly suppresses tumor growth; prolongs animal survival; inhibits lung metastasis; and eliminates systemic toxicities to blood, liver, kidney, and heart tissues. This study achieves a comprehensive understanding of the shape and stiffness effects and demonstrates a hierarchical targeting strategy to address the multiple delivery barriers for chemotherapeutic agents. STATEMENT OF SIGNIFICANCE: The different barriers involved in the drug delivery pathway have inconsistent and even contradictory demands on the shape and stiffness of nanoparticles. In the current study, in situ switching of nanorods (NRs) into spherical nanocapsules (NCs) in tumor tissues is proposed to address these dilemmas. The NR shape ensures long-term blood circulation and high tumor tissue accumulation, while the in situ switching into NCs promotes tissue infiltration and cellular internalization. NCs with different numbers of hydrogel layers also provide a robust system wherein NC stiffness is controlled as a single variable to study stiffness-dependent cellular behaviors. Thus, this straightforward design offers a comprehensive understanding of how the shape and stiffness of nanocarriers affect their biological pathways.

Recent developments in animal venom peptide nanotherapeutics with improved selectivity for cancer cells

Animal venoms are a rich source of bioactive peptides that efficiently modulate key receptors and ion channels involved in cellular excitability to rapidly neutralize their prey or predators. As such, they have been a wellspring of highly useful pharmacological tools for decades. Besides targeting ion channels, some venom peptides exhibit strong cytotoxic activity and preferentially affect cancer over healthy cells. This is unlikely to be driven by an evolutionary impetus, and differences in tumor cells and the tumor microenvironment are probably behind the serendipitous selectivity shown by some venom peptides. However, strategies such as bioconjugation and nanotechnologies are showing potential to improve their selectivity and potency, thereby paving the way to efficiently harness new anticancer mechanisms offered by venom peptides. This review aims to highlight advances in nano- and chemotherapeutic tools and prospective anti-cancer drug leads derived from animal venom peptides.

Drug Resistance in Metastatic Breast Cancer: Tumor Targeted Nanomedicine to the Rescue

Breast cancer, specifically metastatic breast, is a leading cause of morbidity and mortality in women. This is mainly due to relapse and reoccurrence of tumor. The primary reason for cancer relapse is the development of multidrug resistance (MDR) hampering the treatment and prognosis. MDR can occur due to a multitude of molecular events, including increased expression of efflux transporters such as P-gp, BCRP, or MRP1; epithelial to mesenchymal transition; and resistance development in breast cancer stem cells. Excessive dose dumping in chemotherapy can cause intrinsic anti-cancer MDR to appear prior to chemotherapy and after the treatment. Hence, novel targeted nanomedicines encapsulating chemotherapeutics and gene therapy products may assist to overcome cancer drug resistance. Targeted nanomedicines offer innovative strategies to overcome the limitations of conventional chemotherapy while permitting enhanced selectivity to cancer cells. Targeted nanotheranostics permit targeted drug release, precise breast cancer diagnosis, and importantly, the ability to overcome MDR. The article discusses various nanomedicines designed to selectively target breast cancer, triple negative breast cancer, and breast cancer stem cells. In addition, the review discusses recent approaches, including combination nanoparticles (NPs), theranostic NPs, and stimuli sensitive or “smart” NPs. Recent innovations in microRNA NPs and personalized medicine NPs are also discussed. Future perspective research for complex targeted and multi-stage responsive nanomedicines for metastatic breast cancer is discussed.

Strobilanthes crispus bioactive subfraction inhibits tumor progression and improves hematological and morphological parameters in mouse mammary carcinoma model

ETHNOPHARMACOLOGICAL RELEVANCE

Locally known as 'pecah batu', 'bayam karang', 'keci beling' or 'batu jin', the Malaysian medicinal herb, Strobilanthes crispus (S. crispus), is traditionally used by the local communities as alternative or adjuvant remedy for cancer and other ailments and to boost the immune system. S. crispus has demonstrated multiple anticancer therapeutic potential in vitro and in vivo. A pharmacologically active fraction of S. crispus has been identified and termed as F3. Major constituents profiled in F3 include lutein and β-sitosterol.

AIM OF THE STUDY

In this study, the effects of F3, lutein and β-sitosterol on tumor development and metastasis were investigated in 4T1-induced mouse mammary carcinoma model.

MATERIALS AND METHODS

Tumor-bearing mice were fed with F3 (100 mg/kg/day), lutein (50 mg/kg/day) and β-sitosterol (50 mg/kg/day) for 30 days (n = 5 each group). Tumor physical growth parameters, animal body weight and development of secondary tumors were investigated. The safety profile of F3 was assessed using hematological and histomorphological changes on the major organs in normal control mice (NM).

RESULTS

Our findings revealed significant reduction of physical tumor growth parameters in all tumor-bearing mice treated with F3 (TM-F3), lutein (TM-L) or β-sitosterol (TM-β) as compared with the untreated group (TM). Statistically significant reduction in body weight was observed in TM compared to the NM or treated (TM-F3, TM-L and TM-β) groups. Histomorphological examination of tissue sections from the F3-treated group showed normal features of the vital organs (i.e., liver, kidneys, lungs and spleen) which were similar to those of NM. Administration of F3 to NM mice (NM-F3) did not cause significant changes in full blood count values.

CONCLUSION

F3 significantly reduced the total tumor burden and prevented secondary tumor development in metastatic breast cancer without significant toxicities in 4T1-induced mouse mammary carcinoma model. The current study provides further support for therapeutic development of F3 with further pharmacokinetics studies.

Scorpion Toxins and Ion Channels: Potential Applications in Cancer Therapy

Apoptosis, a genetically directed process of cell death, has been studied for many years, and the biochemical mechanisms that surround it are well known and described. There are at least three pathways by which apoptosis occurs, and each pathway depends on extra or intracellular processes for activation. Apoptosis is a vital process, but disturbances in proliferation and cell death rates can lead to the development of diseases like cancer. Several compounds, isolated from scorpion venoms, exhibit inhibitory effects on different cancer cells. Indeed, some of these compounds can differentiate between healthy and cancer cells within the same tissue. During the carcinogenic process, morphological, biochemical, and biological changes occur that enable these compounds to modulate cancer but not healthy cells. This review highlights cancer cell features that enable modulation by scorpion neurotoxins. The properties of the isolated scorpion neurotoxins in cancer cells and the potential uses of these compounds as alternative treatments for cancer are discussed.

Transient receptor potential ion-channel subfamily V member 4: a potential target for cancer treatment

The transient receptor potential ion-channel superfamily consists of nonselective cation channels located mostly on the plasma membranes of numerous animal cell types, which are closely related to sensory information transmission (e.g., vision, pain, and temperature perception), as well as regulation of intracellular Ca2+ balance and physiological activities of growth and development. Transient receptor potential ion channel subfamily V (TRPV) is one of the largest and most diverse subfamilies, including TRPV1-TRPV6 involved in the regulation of a variety of cellular functions. TRPV4 can be activated by various physical and chemical stimuli, such as heat, mechanical force, and phorbol ester derivatives participating in the maintenance of normal cellular functions. In recent years, the roles of TRPV4 in cell proliferation, differentiation, apoptosis, and migration have been extensively studied. Its abnormal expression has also been closely related to the onset and progression of multiple tumors, so TRPV4 may be a target for cancer diagnosis and treatment. In this review, we focused on the latest studies concerning the role of TRPV4 in tumorigenesis and the therapeutic potential. As evidenced by the effects on cancerogenesis, TRPV4 is a potential target for anticancer therapy.

Chlorotoxin targets ERα/VASP signaling pathway to combat breast cancer

Breast cancer is one of the most common malignant tumors among women worldwide. About 70‐75% of primary breast cancers belong to estrogen receptor (ER)‐positive breast cancer. In the development of ER‐positive breast cancer, abnormal activation of the ERα pathway plays an important role and is also a key point leading to the failure of clinical endocrine therapy. In this study, we found that the small molecule peptide chlorotoxin (CTX) can significantly inhibit the proliferation, migration and invasion of breast cancer cells. In in vitro study, CTX inhibits the expression of ERα in breast cancer cells. Further studies showed that CTX can directly bind to ERα and change the protein secondary structure of its LBD domain, thereby inhibiting the ERα signaling pathway. In addition, we also found that vasodilator stimulated phosphoprotein (VASP) is a target gene of ERα signaling pathway, and CTX can inhibit breast cancer cell proliferation, migration, and invasion through ERα/VASP signaling pathway. In in vivo study, CTX significantly inhibits growth of ER overexpressing breast tumor and, more importantly, based on the mechanism of CTX interacting with ERα, we found that CTX can target ER overexpressing breast tumors in vivo. Our study reveals a new mechanism of CTX anti‐ER‐positive breast cancer, which also provides an important reference for the study of CTX anti‐ER‐related tumors.

α-Conotoxin ImI-modified polymeric micelles as potential nanocarriers for targeted docetaxel delivery to α7-nAChR overexpressed non-small cell lung cancer

A micelle system modified with α-Conotoxin ImI (ImI), a potently antagonist for alpha7 nicotinic acetylcholine receptor (α7-nAChR) previously utilized for targeting breast cancer, was constructed. Its targeting efficiency and cytotoxicity against non-small cell lung cancer (NSCLC) highly expressing α7-nAChR was investigated. A549, a non-small cell lung cancer cell line, was selected as the cell model. The cellular uptake study showed that the optimal modification ratio of ImI on micelle surface was 5% and ImI-modification increased intracellular delivery efficiency to A549 cells via receptor-mediated endocytosis. Intracellular Ca²⁺ transient assay demonstrated that ImI modification led to enhanced molecular interaction between nanocarriers and A549 cells. The in vivo near-infrared fluorescence imaging further revealed that ImI-modified micelles could facilitate the drug accumulation in tumor sites compared with non-modified micelles via α7-nAChR mediation. Moreover, docetaxel (DTX) was loaded in ImI-modified nanomedicines to evaluate its in vitro cytotoxicity. As a result, DTX-loaded ImI-PMs exhibited greater anti-proliferation effect on A549 cells compared with non-modified micelles. Generally, our study proved that ImI-modified micelles had targeting ability to NSCLC in addition to breast cancer and it may provide a promising strategy to deliver drugs to NSCLC overexpressing α7-nAChR.

An implantable depot capable of in situ generation of micelles to achieve controlled and targeted tumor chemotherapy

Camptothecin (CPT)-containing promicelle polymers (PM_CPT) based on 4-armed poly(ethylene glycol) (PEG) were developed previously to self-assemble into folate-targeted and glutathione (GSH)-sensitive micelles (M_CPT). To address severe systemic toxicity and lack of tumor specificity implicated in the intravenous administration of M_CPT, a micelle-generating depot has been developed by blend electrospinning of PEG-poly(lactide) (PELA) copolymers, PM_CPT and polyethylene oxide (PEO). Upon implantation of the depot onto a tumor, PM_CPT are sustainably released to self-assemble into M_CPT on the tumor site. The release of PM_CPT is adjusted by varying PEO/PELA ratios and reaches in the range of 23-92% after 30 days of incubation. By making use of the aggregation-induced emission (AIE) features of tetraphenylethylene (TPE) derivatives, the release process of TPE-containing promicelle polymers (PM_TPE) from the depot and the spontaneous formation of micelles (M_TPE) have been monitored from the self-assembly-induced fluorescence light-up both in vitro and in vivo. Compared with intravenous injection of M_CPT, the micelle-generating depot has significantly enhanced micelle accumulation in the tumor for an extended period of time and resulted in stronger tumor inhibitory efficacy, reduced systemic toxicity and more effective inhibition of tumor metastasis, demonstrating great potential for targeted cancer therapy with sustained efficacy.

STATEMENT OF SIGNIFICANCE

The promicelle polymer-co-electrospun fibers are developed to form a micelle-generating depot after implantation onto the tumor. The promicelle polymers are continuously released and simultaneously self-assemble into folate-targeted and glutathione-sensitive micelles, ensuring sustained micelle delivery for more than 30 days. The process of micelle formation in the tumor tissue is visualized in vivo for the first time based on the mechanism of aggregation-induced emission. This in situ micelle formation also prevents premature drug release and rapid clearance from the bloodstream. In addition, these fibers deliver anti-cancer agents directly within tumor cells via dual selectivity (i.e. spatially selective accumulation in tumor tissues via implantation and selective internalization into tumor cells via folate receptor-mediated endocytosis) and on-demand drug release in response to cytosol GSH. They exhibit superior tumor inhibitory efficacy with minimal systemic toxicity, and prevent from malignant metastasis of cancer cells.

Nanomedicine applications in the treatment of breast cancer: current state of the art

Breast cancer is the most common malignant disease in women worldwide, but the current drug therapy is far from optimal as indicated by the high death rate of breast cancer patients. Nanomedicine is a promising alternative for breast cancer treatment. Nanomedicine products such as Doxil^® and Abraxane^® have already been extensively used for breast cancer adjuvant therapy with favorable clinical outcomes. However, these products were originally designed for generic anticancer purpose and not specifically for breast cancer treatment. With better understanding of the molecular biology of breast cancer, a number of novel promising nanotherapeutic strategies and devices have been developed in recent years. In this review, we will first give an overview of the current breast cancer treatment and the updated status of nanomedicine use in clinical setting, then discuss the latest important trends in designing breast cancer nanomedicine, including passive and active cancer cell targeting, breast cancer stem cell targeting, tumor microenvironment-based nanotherapy and combination nanotherapy of drug-resistant breast cancer. Researchers may get insight from these strategies to design and develop nanomedicine that is more tailored for breast cancer to achieve further improvements in cancer specificity, antitumorigenic effect, antimetastasis effect and drug resistance reversal effect.

PTD modified paclitaxel anti-resistant liposomes for treatment of drug-resistant non-small cell lung cancer

CONTEXT

Non-small cell lung carcinoma (NSCLC) is a type of epithelial lung cancer that accounts for approximately 80-85% of lung carcinoma cases. Chemotherapy for the NSCLC is unsatisfactory due to multidrug resistance, nonselectively distributions and the accompanying side effects.

OBJECTIVE

The objective of this study was to develop a kind of PTD modified paclitaxel anti-resistant liposomes to overcome these chemotherapy limitations.

METHOD

The studies were performed on LLT cells and resistant LLT cells in vitro and on NSCLC xenograft mice in vivo, respectively.

RESULTS AND DISCUSSION

In vitro results showed that the liposomes with suitable physicochemical characteristics could significantly increase intracellular uptake in both LLT cells and resistant LLT cells, evidently inhibit the growth of cancer cells, and clearly induce the apoptosis of resistant LLT cells. Studies on resistant LLT cells xenograft mice demonstrated that the liposomes magnificently enhanced the anticancer efficacy in vivo. Involved action mechanisms were down-regulation of adenosine triphosphate binding cassette transporters on resistant LLT cells, and activation of the apoptotic enzymes (caspase 8/9/3).

CONCLUSION

The PTD modified paclitaxel anti-resistant liposomes may provide a promising strategy for treatment of the drug-resistant non-small cell lung cancer.

Diverse Applications of Nanomedicine

The design and use of materials in the nanoscale size range for addressing medical and health-related issues continues to receive increasing interest. Research in nanomedicine spans a multitude of areas, including drug delivery, vaccine development, antibacterial, diagnosis and imaging tools, wearable devices, implants, high-throughput screening platforms, etc. using biological, nonbiological, biomimetic, or hybrid materials. Many of these developments are starting to be translated into viable clinical products. Here, we provide an overview of recent developments in nanomedicine and highlight the current challenges and upcoming opportunities for the field and translation to the clinic.

Toxin bioportides: exploring toxin biological activity and multifunctionality

Toxins have been shown to have many biological functions and to constitute a rich source of drugs and biotechnological tools. We focus on toxins that not only have a specific activity, but also contain residues responsible for transmembrane penetration, which can be considered bioportides-a class of cell-penetrating peptides that are also intrinsically bioactive. Bioportides are potential tools in pharmacology and biotechnology as they help deliver substances and nanoparticles to intracellular targets. Bioportides characterized so far are peptides derived from human proteins, such as cytochrome c (CYCS), calcitonin receptor (camptide), and endothelial nitric oxide synthase (nosangiotide). However, toxins are usually disregarded as potential bioportides. In this review, we discuss the inclusion of some toxins and molecules derived thereof as a new class of bioportides based on structure activity relationship, minimization, and biological activity studies. The comparative analysis of the amino acid residue composition of toxin-derived bioportides and their short molecular variants is an innovative analytical strategy which allows us to understand natural toxin multifunctionality in vivo and plan novel pharmacological and biotechnological products. Furthermore, we discuss how many bioportide toxins have a rigid structure with amphiphilic properties important for both cell penetration and bioactivity.

The design of peptide-amphiphiles as functional ligands for liposomal anticancer drug and gene delivery

Liposomal nanomedicine has led to clinically useful cancer therapeutics like Doxil and DaunoXome. In addition, peptide-functionalized liposomes represent an effective drug and gene delivery vehicle with increased cancer cell specificity, enhanced tumor-penetrating ability and high tumor growth inhibition. The goal of this article is to review the recently published literature of the peptide-amphiphiles that were used to functionalize liposomes, to highlight successful designs that improved drug and gene delivery to cancer cells in vitro, and cancer tumors in vivo, and to discuss the current challenges of designing these peptide-decorated liposomes for effective cancer treatment.

Current Multistage Drug Delivery Systems Based on the Tumor Microenvironment

The development of traditional tumor-targeted drug delivery systems based on EPR effect and receptor-mediated endocytosis is very challenging probably because of the biological complexity of tumors as well as the limitations in the design of the functional nano-sized delivery systems. Recently, multistage drug delivery systems (Ms-DDS) triggered by various specific tumor microenvironment stimuli have emerged for tumor therapy and imaging. In response to the differences in the physiological blood circulation, tumor microenvironment, and intracellular environment, Ms-DDS can change their physicochemical properties (such as size, hydrophobicity, or zeta potential) to achieve deeper tumor penetration, enhanced cellular uptake, timely drug release, as well as effective endosomal escape. Based on these mechanisms, Ms-DDS could deliver maximum quantity of drugs to the therapeutic targets including tumor tissues, cells, and subcellular organelles and eventually exhibit the highest therapeutic efficacy. In this review, we expatiate on various responsive modes triggered by the tumor microenvironment stimuli, introduce recent advances in multistage nanoparticle systems, especially the multi-stimuli responsive delivery systems, and discuss their functions, effects, and prospects.

Nanoparticles for imaging and treatment of metastatic breast cancer

INTRODUCTION

Metastatic breast cancer is one of the most devastating cancers that have no cure. Many therapeutic and diagnostic strategies have been extensively studied in the past decade. Among these strategies, cancer nanotechnology has emerged as a promising strategy in preclinical studies by enabling early identification of primary tumors and metastases, and by effective killing of cancer cells. Areas covered: This review covers the recent progress made in targeting and imaging of metastatic breast cancer with nanoparticles, and treatment using nanoparticle-enabled chemo-, gene, photothermal- and radio-therapies. This review also discusses recent developments of nanoparticle-enabled stem cell therapy and immunotherapy. Expert opinion: Nanotechnology is expected to play important roles in modern therapy for cancers, including metastatic breast cancer. Nanoparticles are able to target and visualize metastasis in various organs, and deliver therapeutic agents. Through targeting cancer stem cells, nanoparticles are able to treat resistant tumors with minimal toxicity to healthy tissues/organs. Nanoparticles are also able to activate immune cells to eliminate tumors. Owing to their multifunctional, controllable and trackable features, nanotechnology-based imaging and therapy could be a highly potent approach for future cancer research and treatment.

rBmαTX14 Increases the Life Span and Promotes the Locomotion of Caenorhabditis Elegans

The scorpion has been extensively used in various pharmacological profiles or as food supplies. The exploration of scorpion venom has been reported due to the presence of recombinant peptides. rBmαTX14 is an α-neurotoxin extracted from the venom gland of the East Asian scorpion Buthus martensii Karsch and can affect ion channel conductance. Here, we investigated the functions of rBmαTX14 using the Caenorhabditis elegans model. Using western blot analysis, rBmαTX14 was shown to be expressed both in the cytoplasm and inclusion bodies in the E.coli Rosetta (DE3) strain. Circular dichroism spectroscopy analysis demonstrated that purified rBmαTX14 retained its biological structures. Next, feeding nematodes with E.coli Rosetta (DE3) expressing rBmαTX14 caused extension of the life span and promoted the locomotion of the nematodes. In addition, we identified several genes that play various roles in the life span and locomotion of C. elegans through microarray analysis and quantitative real-time PCR. Furthermore, if the amino acid site H₁₅ of rBmαTX14 was mutated, rBmαTX14 no longer promoted the C. elegans life span. In conclusion, the results not only demonstrated the functions and mechanism of rBmαTX14 in C. elegans, but also provided the new sight in the utility of recombinant peptides from scorpion venom.

Effects of Animal Venoms and Toxins on Hallmarks of Cancer

Animal venoms are a cocktail of proteins and peptides, targeting vital physiological processes. Venoms have evolved to assist in the capture and digestion of prey. Key venom components often include neurotoxins, myotoxins, cardiotoxins, hematoxins and catalytic enzymes. The pharmacological activities of venom components have been investigated as a source of potential therapeutic agents. Interestingly, a number of animal toxins display profound anticancer effects. These include toxins purified from snake, bee and scorpion venoms effecting cancer cell proliferation, migration, invasion, apoptotic activity and neovascularization. Indeed, the mechanism behind the anticancer effect of certain toxins is similar to that of agents currently used in chemotherapy. For example, Lebein is a snake venom disintegrin which generates anti-angiogenic effects by inhibiting vascular endothelial growth factors (VEGF). In this review article, we highlight the biological activities of animal toxins on the multiple steps of tumour formation or hallmarks of cancer. We also discuss recent progress in the discovery of lead compounds for anticancer drug development from venom components.

Biomimetic strategies for targeted nanoparticle delivery

Nanoparticle‐based drug delivery and imaging platforms have become increasingly popular over the past several decades. Among different design parameters that can affect their performance, the incorporation of targeting functionality onto nanoparticle surfaces has been a widely studied subject. Targeted formulations have the ability to improve efficacy and function by positively modulating tissue localization. Many methods exist for creating targeted nanoformulations, including the use of custom biomolecules such as antibodies or aptamers. More recently, a great amount of focus has been placed on biomimetic targeting strategies that leverage targeting interactions found directly in nature. Such strategies, which have been painstakingly selected over time by the process of evolution to maximize functionality, oftentimes enable scientists to forgo the specialized discovery processes associated with many traditional ligands and help to accelerate development of novel nanoparticle formulations. In this review, we categorize and discuss in‐depth recent works in this growing field of bioinspired research.

131I-labeled multifunctional dendrimers modified with BmK CT for targeted SPECT imaging and radiotherapy of gliomas

Aim: The poly(amidoamine) dendrimers modified with Buthus martensii Karsch chlorotoxin (BmK CT) were developed as a 131I delivery system for glioma-targeted imaging and therapy. Materials & methods: Dendrimers before and after labeling 131I were synthetized and their physicochemical properties were tested. The targeting and therapeutic efficacy of 131I-G5.NHAc-HPAO-(PEG-BmK CT)-(mPEG) dendrimer against glioma was evaluated in vitro and in vivo. Results: All the dendrimers were stable under different conditions. BmK CT modification increased the cellular uptake of dendrimers in C6 glioma cells, but not in the normal RLE-6TN cells. 131I-G5.NHAc-HPAO-(PEG-BmK CT)-(mPEG) dendrimer was radiochemically pure and could be applied in glioma-targeting single-photon emission CT (SPECT) imaging and radiotherapy. Conclusion: 131I-G5.NHAc-HPAO-(PEG-BmK CT)-(mPEG) complex is a promising multifunctional nanoplatform for glioma-specific nuclear imaging and radiotherapy.

Vesicle self-assembly of amphiphilic siderophores produced by bacterial isolates from Soap Lake, Washington

Soap Lake, located in Washington State, is a meromictic soda lake that was the subject of a prior National Science Foundation funded Microbial Observatory. Several organisms inhabiting this lake have been identified as producers of siderophores that are unique in structure. Two isolates found to be of the species Halomonas, SL01 and SL28, were found to produce suites of amphiphilic siderophores consisting of a peptidic head-group, which binds iron appended to fatty acid moieties of various lengths. The ability for siderophores to self-assemble into vesicles was determined for three suites of amphiphilic siderophores of unique structure (two from SL01 and one from SL28). These siderophores resemble the amphiphilic aquachelin siderophores produced by Halomonas aquamarina strain DS40M3, a marine bacterium. Vesicle self-assembly studies were performed by dynamic light scattering and epifluorescence microscopy. The addition of ferric iron (Fe3+) at different equivalents, where an equivalence of iron is defined as equal to the molarity of the siderophore, demonstrated vesicle formation. This was suggested by both dynamic light scattering and epifluorescence microscopy. Bacteria thriving under saline and alkaline conditions are capable of producing unique siderophores that self-assemble in micelles and vesicles due to ferric iron chelation.

In vitro analysis of the anticancer properties of scorpion venom in colorectal and breast cancer cell lines

Scorpion venom contains various types of proteins and peptides that are able to act as inhibitors of neurotransmitter molecules. This is achieved primarily via the inhibition of ion channels. In addition, scorpion venom has been demonstrated to exhibit anticancer properties in prostate and breast cancer, as well as leukemia. The anticancer properties of scorpion venom are due to its inhibitory effect on matrix metalloproteinase (MMP) activity, which leads to reduced motility and invasion in tumor cells. The inhibitory effects of venom on MMPs additionally lead to a reduction in the metastatic potential of malignant tumors. In the present study, the effect of venom obtained from a local serpentarium facility was examined in colorectal and breast cancer cell lines. Cell motility and clonogenic survival assays revealed a significant decrease (60-90%) in cell motility and colony formation, two significant hallmarks of cancer survival, following treatment with various concentrations of venom. These results were in agreement with previous studies demonstrating the anticancer activity of scorpion venom. In conclusion, the venom utilized at the Research Center of Prince Sultan Military Medical City Hospital (Riyadh, Saudi Arabia) possesses significant anticancer potential against colorectal and breast cancer cell lines.

Development of individualized anti-metastasis strategies by engineering nanomedicines

Metastasis is deadly and also tough to treat as it is much more complicated than the primary tumour. Anti-metastasis approaches available so far are far from being optimal. A variety of nanomedicine formulae provide a plethora of opportunities for developing new strategies and means for tackling metastasis. It should be noted that individualized anti-metastatic nanomedicines are different from common anti-cancer nanomedicines as they specifically target different populations of malignant cells. This review briefly introduces the features of the metastatic cascade, and proposes a series of nanomedicine-based anti-metastasis strategies aiming to block each metastatic step. Moreover, we also concisely introduce the advantages of several promising nanoparticle platforms and their potential for constructing state-of-the-art individualized anti-metastatic nanomedicines.

Targeted delivery of cisplatin by LHRH-peptide conjugated dextran nanoparticles suppresses breast cancer growth and metastasis

The metastasis of breast cancer is the leading cause of cancer death in women. In this work, an attempt to simultaneously inhibit the primary tumor growth and organ-specific metastasis by the cisplatin-loaded LHRH-modified dextran nanoparticles (Dex-SA-CDDP-LHRH) was performed in the 4T1 orthotopic mammary tumor metastasis model. With the rationally designed conjugation site of the LHRH ligand, the Dex-SA-CDDP-LHRH nanoparticles maintained the targeting function of LHRH and specifically bound to the LHRH-receptors overexpressed on the surface of 4T1 breast cancer cells. Therefore, the Dex-SA-CDDP-LHRH nanoparticles exhibited improved cellular uptake and promoted cytotoxicity, when compared with the non-targeted Dex-SA-CDDP nanoparticles. Moreover, both the non-targeted and targeted nanoparticles significantly decreased the systemic toxicity of CDDP and increased the maximum tolerated dose of CDDP from 4 to 30mgkg(-1). Importantly, Dex-SA-CDDP-LHRH markedly enhanced the accumulation of CDDP in the injected primary tumor and metastasis-containing organs, and meanwhile significantly reduced the nephrotoxicity of CDDP. Dose-dependent therapeutic effects further demonstrated that the CDDP-loaded LHRH-decorated polysaccharide nanoparticles significantly enhanced the antitumor and antimetastasis efficacy, as compared to the non-targeted nanoparticles. These results suggest that Dex-SA-CDDP-LHRH nanoparticles show great potential for targeted chemotherapy of metastatic breast cancer.

Scorpion venom components as potential candidates for drug development

Scorpions are well known for their dangerous stings that can result in severe consequences for human beings, including death. Neurotoxins present in their venoms are responsible for their toxicity. Due to their medical relevance, toxins have been the driving force in the scorpion natural compounds research field. On the other hand, for thousands of years, scorpions and their venoms have been applied in traditional medicine, mainly in Asia and Africa. With the remarkable growth in the number of characterized scorpion venom components, several drug candidates have been found with the potential to tackle many of the emerging global medical threats. Scorpions have become a valuable source of biologically active molecules, from novel antibiotics to potential anticancer therapeutics. Other venom components have drawn attention as useful scaffolds for the development of drugs. This review summarizes the most promising candidates for drug development that have been isolated from scorpion venoms.

Neurotoxin-directed synthesis and in vitro evaluation of Au nanoclusters

A glioma-specific theranostic agent is prepared by using Chlorotoxin fusion protein to direct the synthesis of Au nanoclusters, which exhibit bright fluorescence and high specificity to target and treat glioma cells.

The use of α-conotoxin ImI to actualize the targeted delivery of paclitaxel micelles to α7 nAChR-overexpressing breast cancer

Alpha7 nicotinic acetylcholine receptor (α7 nAChR), a ligand-gated ion channel, is increasingly emerging as a new tumor target owing to its expression specificity and significancy for cancer. In an attempt to increase the targeted drug delivery to the α7 nAChR-overexpressing tumors, herein, α-conotoxin ImI, a disulfide-rich toxin with highly affinity for α7 nAChR, was modified on the PEG-DSPE micelles (ImI-PMs) for the first time. The DLS, TEM and HPLC detections showed the spherical nanoparticle morphology about 20 nm with negative charge and high drug encapsulation. The ligand modification did not induce significant differences. The immunofluorescence assay confirmed the expression level of α7 nAChR in MCF-7 cells. In vitro and in vivo experiments demonstrated that the α7 nAChR-targeted nanomedicines could deliver more specifically and faster into α7 nAChR-overexpressing MCF-7 cells. Furthermore, fluo-3/AM fluorescence imaging technique indicated that the increased specificity was attributed to the ligand-receptor interaction, and the inducitivity for intracellular Ca(2+) transient by ImI was still remained after modification. Moreover, paclitaxel, a clinical frequently-used anti-tumor drug for breast cancer, was loaded in ImI-modified nanomedicines to evaluate the targeting efficacy. Besides of exhibiting greater cytotoxicity and inducing more cell apoptosis in vitro, paclitaxel-loaded ImI-PMs displayed stronger anti-tumor efficacy in MCF-7 tumor-bearing nu/nu mice. Finally, the active targeting system showed low systemic toxicity and myelosuppression evidenced by less changes in body weight, white blood cells, neutrophilic granulocyte and platelet counts. In conclusion, α7 nAChR is also a promising target for anti-tumor drug delivery and in this case, α-conotoxin ImI-modified nanocarrier is a potential delivery system for targeting α7 nAChR-overexpressing tumors.