Core-shell nanocarriers with high paclitaxel loading for passive and active targeting

Enhancing Tumor Targeted Therapy: The Role of iRGD Peptide in Advanced Drug Delivery Systems

Chemotherapy remains the primary therapeutic approach in treating cancer. The tumor microenvironment (TME) is the complex network surrounding tumor cells, comprising various cell types, such as immune cells, fibroblasts, and endothelial cells, as well as ECM components, blood vessels, and signaling molecules. The often stiff and dense network of the TME interacts dynamically with tumor cells, influencing cancer growth, immune response, metastasis, and resistance to therapy. The effectiveness of the treatment of solid tumors is frequently reduced due to the poor penetration of the drug, which leads to attaining concentrations below the therapeutic levels at the site. Cell-penetrating peptides (CPPs) present a promising approach that improves the internalization of therapeutic agents. CPPs, which are short amino acid sequences, exhibit a high ability to pass cell membranes, enabling them to deliver drugs efficiently with minimal toxicity. Specifically, the iRGD peptide, a member of CPPs, is notable for its capacity to deeply penetrate tumor tissues by binding simultaneously integrins ανβ3/ανβ5 and neuropilin receptors. Indeed, ανβ3/ανβ5 integrins are characteristically expressed by tumor cells, which allows the iRGD peptide to home onto tumor cells. Notably, the respective dual-receptor targeting mechanism considerably increases the permeability of blood vessels in tumors, enabling an efficient delivery of co-administered drugs or nanoparticles into the tumor mass. Therefore, the iRGD peptide facilitates deeper drug penetration and improves the efficacy of co-administered therapies. Distinctively, we will focus on the iRGD mechanism of action, drug delivery systems and their application, and deliberate future perspectives in developing iRGD-conjugated therapeutics. In summary, this review discusses the potential of iRGD in overcoming barriers to drug delivery in cancer to maximize treatment efficiency while minimizing side effects.

iRGD-Guided Silica/Gold Nanoparticles for Efficient Tumor-Targeting and Enhancing Antitumor Efficacy Against Breast Cancer

Background

Breast cancer presents significant challenges due to the limited effectiveness of available treatments and the high likelihood of recurrence. iRGD possesses both RGD sequence and C-terminal sequence and has dual functions of targeting and membrane penetration. iRGD-modified nanocarriers can enhance drug targeting of tumor vascular endothelial cells and penetration of new microvessels, increasing drug concentration in tumor tissues.

Methods

The amidation reaction was carried out between SiO2/AuNCs and iRGD/PTX, yielding a conjugated drug delivery system (SiO2/AuNCs-iRGD/PTX, SAIP@NPs). The assessment encompassed the characterization of the morphology, particle size distribution, physicochemical properties, in vitro release profile, cytotoxicity, and cellular uptake of SAIP@NPs. The tumor targeting and anti-tumor efficacy of SAIP@NPs were assessed using a small animal in vivo imaging system and a tumor-bearing nude mice model, respectively. The tumor targeting and anti-tumor efficacy of SAIP@NPs were assessed utilizing a small animal in vivo imaging system and an in situ nude mice breast cancer xenograft model, respectively.

Results

The prepared SAIP@NPs exhibited decent stability and a certain slow-release effect in phosphate buffer (PBS, pH 7.4). In vitro studies had shown that, due to the dual functions of transmembrane and targeting of iRGD peptide, SAIP@NPs exhibited strong binding to integrin αvβ3, which was highly expressed on the membrane of MDA-MB-231 cells, improving the uptake capacity of tumor cells, inhibiting the rapid growth of tumor cells, and promoting tumor cell apoptosis. The results of animal experiments further proved that SAIP@NPs had longer residence time in tumor sites, stronger anti-tumor effect, and no obvious toxicity to major organs of experimental animals.

Conclusion

The engineered SAIP@NPs exhibited superior functionalities including efficient membrane permeability, precise tumor targeting, and imaging, thereby significantly augmenting the therapeutic efficacy against breast cancer with a favorable safety profile.

Cancer therapy with iRGD as a tumor-penetrating peptide

One of the primary threats in tumor treatment revolves around the limited ability to penetrate tumor sites, leading to reduced therapeutic effectiveness, which remains a critical concern. Recently gaining importance are novel peptides, namely CRGDK/RGPD/EC (iRGD), that possess enhanced tumor-penetrating and inhibitory properties. These peptides specifically target and penetrate tumors by binding to αvβ integrins, namely αvβ3 and αvβ5, as well as NRP-1 receptors. Remarkably abundant on both the vasculature and tumor cell surfaces, these peptides show promising potential for improving tumor treatment outcomes. As a result, iRGD penetrated deep into the tumor tissues with biological products, contrast agents (imaging agents), antitumor drugs, and immune modulators after co-injecting them with peptides or chemically linked to peptides. The synthesis of iRGD peptides is a relatively straightforward process compared to the synthesis of other traditional peptides, and they significantly improved tumor tissue penetration inhibiting tumor metastasis effectively. Recent studies demonstrate the effectiveness of iRGD-driven dual-targeting chemotherapeutics on cancer cells, and the nanocarriers were modified with iRGD, serving as a favorable delivery strategy of payloads for deeper tumor regions. This review aims to provide an overview to emphasize the recent advancements and advantages of iRGD in treating and imaging various cancers.

Cancer Nanomedicine: Emerging Strategies and Therapeutic Potentials

Cancer continues to pose a severe threat to global health, making pursuing effective treatments more critical than ever. Traditional therapies, although pivotal in managing cancer, encounter considerable challenges, including drug resistance, poor drug solubility, and difficulties targeting tumors, specifically limiting their overall efficacy. Nanomedicine's application in cancer therapy signals a new epoch, distinguished by the improvement of the specificity, efficacy, and tolerability of cancer treatments. This review explores the mechanisms and advantages of nanoparticle-mediated drug delivery, highlighting passive and active targeting strategies. Furthermore, it explores the transformative potential of nanomedicine in tumor therapeutics, delving into its applications across various treatment modalities, including surgery, chemotherapy, immunotherapy, radiotherapy, photodynamic and photothermal therapy, gene therapy, as well as tumor diagnosis and imaging. Meanwhile, the outlook of nanomedicine in tumor therapeutics is discussed, emphasizing the need for addressing toxicity concerns, improving drug delivery strategies, enhancing carrier stability and controlled release, simplifying nano-design, and exploring novel manufacturing technologies. Overall, integrating nanomedicine in cancer treatment holds immense potential for revolutionizing cancer therapeutics and improving patient outcomes.

Insight on nano drug delivery systems with targeted therapy in treatment of oral cancer

Oral cancer is a type of cancer that develops in the mouth and is one of the deadliest malignancies in the world. Currently surgical, radiation therapy, and chemotherapy are most common treatments. Better treatment and early detection strategies are required. Chemotherapeutic drugs fail frequently due to toxicity and poor tumor targeting. There are high chances of failure of chemotherapeutic drugs due to toxicity. Active, passive, and immunity-targeting techniques are devised for tumor-specific activity. Nanotechnology-based drug delivery systems are the best available solution and important for precise targeting. Nanoparticles, liposomes, exosomes, and cyclodextrins are nano-based carriers for drug delivery. Nanotechnology is being used to develop new techniques such as intratumoral injections, microbubble mediated ultrasonic therapy, phototherapies, and site-specific delivery. This systematic review delves into the details of such targeted and nano-based drug delivery systems in order to improve patient health and survival rates in oral cancer.

Nanoparticle-mediated therapeutic management in cholangiocarcinoma drug targeting: Current progress and future prospects

Patients with cholangiocarcinoma (CCA) often have an unfavorable prognosis because of its insidious nature, low resectability rate, and poor response to anticancer drugs and radiotherapy, which makes early detection and treatment difficult. At present, CCA has a five-year overall survival rate (OS) of only 5%, despite advances in therapies. New an increasing number of evidence suggests that nanoplatforms may play a crucial role in enhancing the pharmacological effects and in reducing both short- and long-term side effects of cancer treatment. This document reviews the advantages and shortcomings of nanoparticles such as liposomes, polymeric nanoparticle，inorganic nanoparticle, nano-metals and nano-alloys, carbon dots, nano-micelles, dendrimer, nano-capsule, bio-Nanomaterials in the diagnosis and treatment of CCA and discuss the current challenges in of nanoplatforms for CCA.

Precision Nanotoxicology in Drug Development: Current Trends and Challenges in Safety and Toxicity Implications of Customized Multifunctional Nanocarriers for Drug-Delivery Applications

The dire need for the assessment of human and environmental endangerments of nanoparticulate material has motivated the formulation of novel scientific tools and techniques to detect, quantify, and characterize these nanomaterials. Several of these paradigms possess enormous possibilities for applications in many of the realms of nanotoxicology. Furthermore, in a large number of cases, the limited capabilities to assess the environmental and human toxicological outcomes of customized and tailored multifunctional nanoparticles used for drug delivery have hindered their full exploitation in preclinical and clinical settings. With the ever-compounded availability of nanoparticulate materials in commercialized settings, an ever-arising popular debate has been egressing on whether the social, human, and environmental costs associated with the risks of nanomaterials outweigh their profits. Here we briefly review the various health, pharmaceutical, and regulatory aspects of nanotoxicology of engineered multifunctional nanoparticles in vitro and in vivo. Several aspects and issues encountered during the safety and toxicity assessments of these drug-delivery nanocarriers have also been summarized. Furthermore, recent trends implicated in the nanotoxicological evaluations of nanoparticulate matter in vitro and in vivo have also been discussed. Due to the absence of robust and rigid regulatory guidelines, researchers currently frequently encounter a larger number of challenges in the toxicology assessment of nanocarriers, which have also been briefly discussed here. Nanotoxicology has an appreciable and significant part in the clinical translational development as well as commercialization potential of nanocarriers; hence these aspects have also been touched upon. Finally, a brief overview has been provided regarding some of the nanocarrier-based medicines that are currently undergoing clinical trials, and some of those which have recently been commercialized and are available for patients. It is expected that this review will instigate an appreciable interest in the research community working in the arena of pharmaceutical drug development and nanoformulation-based drug delivery.

Engineering nanosystems to overcome barriers to cancer diagnosis and treatment

Over the past two decades, multidisciplinary investigations into the development of nanoparticles for medical applications have continually increased. However, nanoparticles are still subject to biological barriers and biodistribution challenges, which limit their overall clinical potential. This has motivated the implementation of innovational modifications to a range of nanoparticle formulations designed for cancer imaging and/or cancer treatment to overcome specific barriers and shift the accumulation of payloads toward the diseased tissues. In recent years, novel technological and chemical approaches have been employed to modify or functionalize the surface of nanoparticles or manipulate the characteristics of nanoparticles. Combining these approaches with the identification of critical biomarkers provides new strategies for enhancing nanoparticle specificity for both cancer diagnostic and therapeutic applications. This review discusses the most recent advances in the design and engineering of nanoparticles as well as future directions for developing the next generation of nanomedicines.

Dual Targeting of Cancer Cells and MMPs with Self-Assembly Hybrid Nanoparticles for Combination Therapy in Combating Cancer

The co-delivery of chemotherapeutic agents and immune modulators to their targets remains to be a great challenge for nanocarriers. Here, we developed a hybrid thermosensitive nanoparticle (TMNP) which could co-deliver paclitaxel-loaded transferrin (PTX@TF) and marimastat-loaded thermosensitive liposomes (MMST/LTSLs) for the dual targeting of cancer cells and the microenvironment. TMNPs could rapidly release the two payloads triggered by the hyperthermia treatment at the site of tumor. The released PTX@TF entered cancer cells via transferrin-receptor-mediated endocytosis and inhibited the survival of tumor cells. MMST was intelligently employed as an immunomodulator to improve immunotherapy by inhibiting matrix metalloproteinases to reduce chemokine degradation and recruit T cells. The TMNPs promoted the tumor infiltration of CD3+ T cells by 2-fold, including memory/effector CD8+ T cells (4.2-fold) and CD4+ (1.7-fold), but not regulatory T cells. Our in vivo anti-tumor experiment suggested that TMNPs possessed the highest tumor growth inhibitory rate (80.86%) compared with the control group. We demonstrated that the nanoplatform could effectively inhibit the growth of tumors and enhance T cell recruitment through the co-delivery of paclitaxel and marimastat, which could be a promising strategy for the combination of chemotherapy and immunotherapy for cancer treatment.

Heptamethine Cyanine Dye MHI-148-Mediated Drug Delivery System to Enhance the Anticancer Efficiency of Paclitaxel

Introduction

Paclitaxel (PTX) is a conventional chemotherapeutic drug that effectively treats various cancers. The cellular uptake and therapeutic potential of PTX are limited by its slow penetration and low solubility in water. The development of cancer chemotherapy methods is currently facing considerable challenges with respect to the delivery of the drugs, particularly in targeting the tumor site without exerting detrimental effects on the healthy surrounding cells. One possibility for improving the therapeutic potential is through the development of tumor-targeted delivery methods.

Methods

We successfully synthesized paclitaxel-MHI-148 conjugates (PTX-MHI) by coupling PTX with the tumor-targeting heptamethine cyanine dye MHI-148. Synthesis and purification were characterized using the absorbance spectrum and the results of time-of-flight mass spectrometry. Cellular uptake and cytotoxicity studies were conducted in vitro and in vivo.

Results

PTX-MHI accumulates in tumor cells but not in normal cells, as observed by in vitro near-infrared fluorescent (NIRF) imaging along with in vivo NIRF imaging and organ biodistribution studies. We observed that MHI-148-conjugated PTX shows greater efficiency in cancer cells than PTX alone, even in the absence of light treatment. PTX-MHI could also be used for specific drug delivery to intracellular compartments, such as the mitochondria and lysosomes of cancer cells, to improve the outcomes of tumor-targeting therapy.

Conclusion

The results indicated that PTX-MHI-mediated cancer therapy exerts an excellent inhibitory effect on colon carcinoma (HT-29) cell growth with low toxicity in normal fibroblasts (NIH3T3).

Liposomes: An Emerging Approach for the Treatment of Cancer

BACKGROUND

Conventional drug delivery agents for a life-threatening disease, i.e., cancer, lack specificity towards cancer cells, producing a greater degree of side effects in the normal cells with a poor therapeutic index. These toxic side effects often limit dose escalation of anti-cancer drugs, leading to incomplete tumor suppression/ cancer eradication, early disease relapse, and ultimately, the development of drug resistance. Accordingly, targeting the tumor vasculatures is essential for the treatment of cancer.

OBJECTIVE

To search and describe a safer drug delivery carrier for the treatment of cancer with reduced systemic toxicities.

METHOD

Data were collected from Medline, PubMed, Google Scholar, Science Direct using the following keywords: 'liposomes', 'nanocarriers', 'targeted drug delivery', 'ligands', 'liposome for anti-cancerous drugs', 'treatment for cancer' and 'receptor targeting.'

RESULTS

Liposomes have provided a safe platform for the targeted delivery of encapsulated anti-cancer drugs for the treatment of cancer, which results in the reduction of the cytotoxic side effects of anti-cancer drugs on normal cells.

CONCLUSION

Liposomal targeting is a better emerging approach as an advanced drug delivery carrier with targeting ligands for anti-cancer agents.

Delivery of cancer therapies by synthetic and bio-inspired nanovectors

BACKGROUND

As a complement to the clinical development of new anticancer molecules, innovations in therapeutic vectorization aim at solving issues related to tumor specificity and associated toxicities. Nanomedicine is a rapidly evolving field that offers various solutions to increase clinical efficacy and safety. MAIN: Here are presented the recent advances for different types of nanovectors of chemical and biological nature, to identify the best suited for translational research projects. These nanovectors include different types of chemically engineered nanoparticles that now come in many different flavors of 'smart' drug delivery systems. Alternatives with enhanced biocompatibility and a better adaptability to new types of therapeutic molecules are the cell-derived extracellular vesicles and micro-organism-derived oncolytic viruses, virus-like particles and bacterial minicells. In the first part of the review, we describe their main physical, chemical and biological properties and their potential for personalized modifications. The second part focuses on presenting the recent literature on the use of the different families of nanovectors to deliver anticancer molecules for chemotherapy, radiotherapy, nucleic acid-based therapy, modulation of the tumor microenvironment and immunotherapy.

CONCLUSION

This review will help the readers to better appreciate the complexity of available nanovectors and to identify the most fitting "type" for efficient and specific delivery of diverse anticancer therapies.

Towards precision nanomedicine for cerebrovascular diseases with emphasis on Cerebral Cavernous Malformation (CCM)

Introduction: Cerebrovascular diseases encompass various disorders of the brain vasculature, such as ischemic/hemorrhagic strokes, aneurysms, and vascular malformations, also affecting the central nervous system leading to a large variety of transient or permanent neurological disorders. They represent major causes of mortality and long-term disability worldwide, and some of them can be inherited, including Cerebral Cavernous Malformation (CCM), an autosomal dominant cerebrovascular disease linked to mutations in CCM1/KRIT1, CCM2, or CCM3/PDCD10 genes.Areas covered: Besides marked clinical and etiological heterogeneity, some commonalities are emerging among distinct cerebrovascular diseases, including key pathogenetic roles of oxidative stress and inflammation, which are increasingly recognized as major disease hallmarks and therapeutic targets. This review provides a comprehensive overview of the different clinical features and common pathogenetic determinants of cerebrovascular diseases, highlighting major challenges, including the pressing need for new diagnostic and therapeutic strategies, and focusing on emerging innovative features and promising benefits of nanomedicine strategies for early detection and targeted treatment of such diseases.Expert opinion: Specifically, we describe and discuss the multiple physico-chemical features and unique biological advantages of nanosystems, including nanodiagnostics, nanotherapeutics, and nanotheranostics, that may help improving diagnosis and treatment of cerebrovascular diseases and neurological comorbidities, with an emphasis on CCM disease.

iRGD Peptide as a Tumor-Penetrating Enhancer for Tumor-Targeted Drug Delivery

The unique structure and physiology of a tumor microenvironment impede intra-tumoral penetration of chemotherapeutic agents. A novel iRGD peptide that exploits the tumor microenvironment can activate integrin-dependent binding to tumor vasculatures and neuropilin-1 (NRP-1)-dependent transport to tumor tissues. Recent studies have focused on its dual-targeting ability to achieve enhanced penetration of chemotherapeutics for the efficient eradication of cancer cells. Both the covalent conjugation and the co-administration of iRGD with chemotherapeutic agents and engineered delivery vehicles have been explored. Interestingly, the iRGD-mediated drug delivery also enhances penetration through the blood-brain barrier (BBB). Recent studies have shown its synergistic effect with BBB disruptive techniques. The efficacy of immunotherapy involving immune checkpoint blockades has also been amplified by using iRGD as a targeting moiety. In this review, we presented the recent advances in iRGD technology, focusing on cancer treatment modalities, including the current clinical trials using iRGD. The iRGD-mediated nano-carrier system could serve as a promising strategy in drug delivery to the deeper tumor regions, and be combined with various therapeutic interventions due to its novel targeting ability.

Nanomedicine review: clinical developments in liposomal applications

Background

In recent years, disease treatment has evolved strategies that require increase in pharmaceutical agent’s efficacy and selectivity while decreasing their toxicity in normal tissues. These requirements have led to the development of nanoscale liposome systems for drug release. This review focuses on lipid features, pharmacological properties of liposomal formulations and the clinical studies of their application.

Main body

Several lipids are available, but their properties could affect pharmacological or clinical efficiency of drug formulations. Many liposomal formulations have been developed and are currently on the market. Proper selection of lipid is essential for the pharmacological effect to be improved. Most of the formulations use mainly zwitterionic, cationic or anionic lipids, PEG and/or cholesterol, which have different effects on stability, pharmacokinetics and delivery of the drug formulation. Clinical trials have shown that liposomes are pharmacologically and pharmacokinetically more efficient than drug-alone formulations in treating acute myeloid leukemia, hepatitis A, pain management, ovary, gastric breast and lung cancer, among others.

Conclusion

Liposomal formulations are less toxic than drugs alone and have better pharmacological parameters. Although they seem to be the first choice for drug delivery systems for various diseases, further research about dosage regimen regarding dose and time needs to be carried out.

Ultrasonic-assisted fabrication and release kinetics of two model redox-responsive magnetic microcapsules for hydrophobic drug delivery

The smart biocompatible carriers have an advantage in the high-efficiency delivery and stimuli-responsive release of drugs. This study describes two model magnetic microcapsules (MMC) fabricated by sonicating the hydrophobic drug-loaded oil phase in an albumin aqueous solution, where magnetic nanoparticles are either encapsulated into the core or embedded onto the albumin shell. The as-prepared MMC with magnetic shell (MS) or with magnetic core (MC) shows an appropriate dispersibility with a well-defined spherical morphology in water, an excellent magnetism-mediated shifting ability for targeted drug delivery, and a good biocompatibility for high-level cell viability. Moreover, both the two microcapsules also show a high efficiency to trap the hydrophobic drugs, where the embedding ratios are 87.41% for MMC-MS and 95.31% for MMC-MC, respectively. Meanwhile in current study, the release kinetics and mechanism reveal that the sulfhydryl-crosslinked shell structure endows the MMC with a redox-responsive behavior to release the contents for controlled drug release, and the release rate or the release amount can be adjusted by changing the dosage of reducing agent. Therefore, the MMC have great potential as a smart carrier of hydrophobic drugs for enhancing the therapeutic efficiency.

iRGD: A Promising Peptide for Cancer Imaging and a Potential Therapeutic Agent for Various Cancers

Poor penetration into the tumor parenchyma and the reduced therapeutic efficacy of anticancer drugs and other medications are the major problems in tumor treatment. A new tumor-homing and penetrating peptide, iRGD (CRGDK/RGPD/EC), can be effectively used to combine and deliver imaging agents or anticancer drugs into tumors. The different “vascular zip codes” expressed in different tissues can serve as targets for docking-based (synaptic) delivery of diagnostic and therapeutic molecules. αv-Integrins are abundantly expressed in the tumor vasculature, where they are recognized by peptides containing the RGD integrin recognition motif. The iRGD peptide follows a multistep tumor-targeting process: First, it is proteolytically cleaved to generate the CRGDK fragment by binding to the surface of cells expressing αv integrins (αvβ3 and αvβ5). Then, the fragment binds to neuropilin-1 and penetrates the tumor parenchyma more deeply. Compared with conventional RGD peptides, the affinity of iRGD for αv integrins is in the mid to low nanomolar range, and the CRGDK fragment has a stronger affinity for neuropilin-1 than that for αv integrins because of the C-terminal exposure of a conditional C-end Rule (CendR) motif (R/KXXR/K), whose receptor proved to be neuropilin-1. Consequently, these advantages facilitate the transfer of CRGDK fragments from integrins to neuropilin-1 and consequently deeper penetration into the tumor. Due to its specific binding and strong affinity, the iRGD peptide can deliver imaging agents and anticancer drugs into tumors effectively and deeply, which is useful in detecting the tumor, blocking tumor growth, and inhibiting tumor metastasis. This review aims to focus on the role of iRGD in the imaging and treatment of various cancers.

Drug Carrier-Oriented Polygeline for Preparing Novel Polygeline-Bound Paclitaxel Nanoparticles

Polygeline is a highly promising drug carrier-oriented material for important applications in pharmacy field due to its low-cost and unique properties similar to albumin. In this study, polygeline-bound paclitaxel nanoparticles (Npb-PTXS) were fabricated through a combination of low-pressure emulsification and high-pressure homogenization. The effects of a series of production parameters on mean particle size, particle size distribution and drug loading of Npb-PTXS were systematically evaluated. The characteristics of Npb-PTXS, such as surface morphology, physical status of paclitaxel (PTX) in Npb-PTXS, redispersibility of Npb-PTXS in purified water and bioavailability in vivo were also investigated. It is revealed that the optimal preparation conditions included an aqueous phase pH value of about 6.5, protein mass concentration of 0.33%, with mass ratio of PTX to protein of 30%, high pressure of 1200 bar, high-pressure passes of 25 times and low-pressure emulsifying passes of 20 times. Obtained Npb-PTXS shows good resolubility compared to commercially available Abraxane^®, containing round or oval shaped particles with mean particle size of around 188.3 nm, polydispersity index of 0.163 and zeta potential of -31.1 mV. PTX in Npb-PTX is amorphous, and its content is approximately 12.04%. Encapsulation efficiency of Npb-PTXS reaches 81.2%. Moreover, in vivo pharmacokinetic studies showed that the intravenous relative bioavailability of Npb-PTXS to Abraxane was 83.89%.

Paclitaxel Encapsulation into Dual-Functionalized Multi-Walled Carbon Nanotubes

This work reports the synthesis of multi-walled carbon nanotubes (CNTs) from xylene/ferrocene using catalytic chemical vapor deposition technique. Following characterization using transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), and Raman spectroscopy, CNT surface was dual-functionalized using ethylenediamine and phenylboronic acid groups. Average diameter of CNTs was calculated to be 16.5 nm. EDX spectra confirmed the existence of carbonaceous deposits on the tube's surface. Scattered electron diffraction and X-ray peak broadening calculations showed consistent inter-planer distance of the grown CNTs. Chemical functionalization, confirmed from FT-IR and Raman spectra, showed an enhanced dispersibility of CNTs in water. We describe the changes in the first- and second-order regions of the Raman spectra following the encapsulation of an anti-cancer drug, paclitaxel (PLX), into the free volume of functionalized CNTs. High PLX loading, achieved through its non-covalent π-π stacking within the CNT interior, is confirmed through the blue-shifted, softened G band in the Raman spectrum. While not addressed here, we will exploit this dual functionalization tactic to elaborate the relative role of attached moieties in the affinity interaction of CNTs with extra-cellular sialic acid, a biological target showing metastatic stage-dependent over-expression in colon cancer cells.

Tumor targeting via EPR: Strategies to enhance patient responses

The tumor accumulation of nanomedicines relies on the enhanced permeability and retention (EPR) effect. In the last 5-10 years, it has been increasingly recognized that there is a large inter- and intra-individual heterogeneity in EPR-mediated tumor targeting, explaining the heterogeneous outcomes of clinical trials in which nanomedicine formulations have been evaluated. To address this heterogeneity, as in other areas of oncology drug development, we have to move away from a one-size-fits-all tumor targeting approach, towards methods that can be employed to individualize and improve nanomedicine treatments. To this end, efforts have to be invested in better understanding the nature, the complexity and the heterogeneity of the EPR effect, and in establishing systems and strategies to enhance, combine, bypass and image EPR-based tumor targeting. In the present manuscript, we summarize key studies in which these strategies are explored, and we discuss how these approaches can be employed to enhance patient responses.

Nanoplatform Assembled from a CD44-Targeted Prodrug and Smart Liposomes for Dual Targeting of Tumor Microenvironment and Cancer Cells

The tumor microenvironment (TME) plays a critical role in tumor initiation, progression, invasion, and metastasis. Therefore, a therapy that combines chemotherapeutic drugs with a TME modulator could be a promising route for cancer treatment. This paper reports a nanoplatform self-assembled from a hyaluronic acid (HA)-paclitaxel (PTX) (HA-PTX) prodrug and marimastat (MATT)-loaded thermosensitive liposomes (LTSLs) (MATT-LTSLs) for the dual targeting of the TME and cancer cells. Interestingly, the prodrug HA-PTX can self-assemble on both positively and negatively charged liposomes, forming hybrid nanoparticles (HNPs, 100 nm). Triggered by mild hyperthermia, HA-PTX/MATT-LTSLs HNPs rapidly release their payloads into the extracellular environment, and the released HA-PTX quickly enters 4T1 cells through a CD44-HA affinity. The HNPs possess promoted tumor accumulation (1.6-fold), exhibit deep tumor penetration, and significantly inhibit the tumor growth (10-fold), metastasis (100%), and angiogenesis (10-fold). Importantly, by targeting the TME and maintaining its integrity via inhibiting the expression and activity of matrix metalloproteinases (>5-fold), blocking the fibroblast activation by downregulating the TGF-β1 expression (5-fold) and suppressing the degradation of extracellular matrix, the HNPs allow for significant metastasis inhibition. Overall, these findings indicate that a prodrug of an HA-hydrophobic-active compound and liposomes can be self-assembled into a smart nanoplatform for the dual targeting of the TME and tumor cells and efficient combined treatment; additionally, the co-delivery of MATT and HA-PTX with the HNPs is a promising approach for the treatment of metastatic cancer. This study creates opportunities for fabricating multifunctional nanodevices and offers an efficient strategy for disease therapy.

Cucurbit[8]uril-Based Giant Supramolecular Vesicles: Highly Stable, Versatile Carriers for Photoresponsive and Targeted Drug Delivery

Highly stable giant supramolecular vesicles were constructed by hierarchical self-assembly of cucurbit[8]uril (CB[8])-based supra-amphiphiles for photoresponsive and targeted intracellular drug delivery. These smart vesicles can encapsulate the model drugs with high loading efficiencies and then release them by manipulating photoswitchable CB[8] heteroternary complexation to regulate the formation and dissociation of supra-amphiphiles that cause dramatic morphological changes of the assemblies to achieve remote optically controlled drug delivery. More importantly, the confocal microscopy analysis, cellular uptake experiment, and cell viability assay have shown that the giant vesicles are able to maintain the structural integrity and stability within actual cellular environments and exhibit obvious advantages for intracellular drug delivery such as low toxicity, easy surface modification for tumor-targeting selectivity, and rapid internalization into different human cancer cell lines. A synergistic mechanism that integrates multiple pathways including energy-dependent endocytosis, macropinocytosis, cholesterol-dependent endocytosis, and microtubule-related endocytosis was determined to facilitate the internalization process. Moreover, cytotoxicity experiments and flow cytometric analysis have demonstrated that the doxorubicin hydrochloride-loaded vesicles exhibited a significant therapeutic effect for tumor cells upon UV light irradiation, which makes the photoresponsive system more promising for potential applications in pharmaceutically relevant fields.

Niclosamide loaded biodegradable chitosan nanocargoes: an in vitro study for potential application in cancer therapy

Chitosan nanoparticles can advance the pharmacological and therapeutic properties of chemotherapeutic agents by controlling release rates and targeted delivery process, which eliminates the limitations of conventional anti-cancer therapies and they are also safe as well as cost-effective. The aim of present study is to explore the anti-tumour effect of niclosamide in lung and breast cancer cell lines using biocompatible and biodegradable carrier where nanoparticles loaded with hydrophobic drug (niclosamide) were synthesized, characterized and applied as a stable anti-cancer agent. Niclosamide loaded chitosan nanoparticles (Nic-Chi Np's) of size approximately 100-120 nm in diameter containing hydrophobic anti-cancer drug, i.e. niclosamide, were prepared. Physico-chemical characterization confirms that the prepared nanoparticles are spherical, monodispersed and stable in aqueous systems. The therapeutic efficacy of Nic-Chi Np's was evaluated against breast cancer cell line (MCF-7) and human lung cancer cell line (A549). MTT assay reveals the cell viability of the prepared Nic-Chi Np's against A549 and MCF-7 cells and obtained an IC₅₀ value of 8.75 µM and 7.5 µM, respectively. Acridine orange/ethidium bromide dual staining results verified the loss of the majority of the cells by apoptosis. Flow cytometer analysis quantified the generation of intracellular reactive oxygen species (ROS) and signified that exposure to a higher concentration (2 × IC₅₀) of Nic-Chi Np's resulted in elevated ROS generation. Notably, Nic-Chi Np treatment showed more apoptosis and cell death in MCF-7 as compared to A549. Further, the remarkable induction of apoptosis by Nic-Chi Np's was confirmed by semi-quantitative reverse transcription polymerase chain reaction, scanning electron microscopy and cell-cycle analysis. Thus, Nic-Chi Np's may have a great potential even at low concentration for anti-cancer therapy and may replace or substitute more toxic anti-mitotic drugs in the near future.

Advances in structural design of lipid-based nanoparticle carriers for delivery of macromolecular drugs, phytochemicals and anti-tumor agents

The present work highlights recent achievements in development of nanostructured dispersions and biocolloids for drug delivery applications. We emphasize the key role of biological small-angle X-ray scattering (BioSAXS) investigations for the nanomedicine design. A focus is given on controlled encapsulation of small molecular weight phytochemical drugs in lipid-based nanocarriers as well as on encapsulation of macromolecular siRNA, plasmid DNA, peptide and protein pharmaceuticals in nanostructured nanoparticles that may provide efficient intracellular delivery and triggered drug release. Selected examples of utilisation of the BioSAXS method for characterization of various types of liquid crystalline nanoorganizations (liposome, spongosome, cubosome, hexosome, and nanostructured lipid carriers) are discussed in view of the successful encapsulation and protection of phytochemicals and therapeutic biomolecules in the hydrophobic or the hydrophilic compartments of the nanocarriers. We conclude that the structural design of the nanoparticulate carriers is of crucial importance for the therapeutic outcome and the triggered drug release from biocolloids.

Targeted drug delivery using iRGD peptide for solid cancer treatment

Many solid tumor types, such as pancreatic cancer, have a generally poor prognosis, in part because the delivery of therapeutic regimen is prohibited by pathological abnormalities that block access to tumor vasculature, leading to poor bioavailability. Recent development of tumor penetrating iRGD peptide that is covalently conjugated on nanocarriers' surface or co-administered with nanocarriers becomes a popular approach for tumor targeting. More importantly, scientists have unlocked an important tumor transcytosis mechanism by which drug carrying nanoparticles directly access solid tumors (without the need of leaky vasculature), thereby allowing systemically injected nanocarriers more abundantly distribute at tumor site with improved efficacy. In this focused review, we summarized the design and implementation strategy for iRGD-mediated tumor targeting. This includes the working principle of such peptide and discussion on patient-specific iRGD effect in vivo, commensurate with the level of key biomarker (i.e. neuropilin-1) expression on tumor vasculature. This highlights the necessity to contemplate the use of a personalized approach when iRGD technology is used in clinic.

Cytosolic co-delivery of miRNA-34a and docetaxel with core-shell nanocarriers via caveolae-mediated pathway for the treatment of metastatic breast cancer

Co-delivery of microRNAs and chemotherapeutic drugs into tumor cells is an attractive strategy for synergetic breast cancer therapy due to their complementary mechanisms. In this work, a core-shell nanocarrier coated by cationic albumin was developed to simultaneously deliver miRNA-34a and docetaxel (DTX) into breast cancer cells for improved therapeutic effect. The co-delivery nanocarriers showed a spherical morphology with an average particle size of 183.9 nm, and they efficiently protected miRNA-34a from degradation by RNase and serum. Importantly, the nanocarriers entered the cytosol via a caveolae-mediated pathway without entrapment in endosomes/lysosomes, thus improving the utilization of the cargo. In vitro, the co-delivery nanocarriers suppressed the expression of anti-apoptosis gene Bcl-2 at both transcription and protein levels, inhibited tumor cell migration and efficiently induced cell apoptosis and cytotoxicity. In vivo, the co-delivery nanocarriers prolonged the blood circulation of DTX, enhanced tumor accumulation of the cargo and significantly inhibited tumor growth and metastasis in 4T1-tumor bearing mice models. Taken together, the present nanocarrier co-loading with DTX and miRNA-34a is a new nanoplatform for the combination of insoluble drugs and gene/protein drugs and provides a promising strategy for the treatment of metastatic breast cancer.

Self-assembly of glutamic acid linked paclitaxel dimers into nanoparticles for chemotherapy

In this work, a glutamic acid linked paclitaxel (PTX) dimer (Glu-PTX₂) with high PTX content of 88.9wt% was designed and synthesized. Glu-PTX₂ could self-assemble into nanoparticles (Glu-PTX₂ NPs) in aqueous solution to increase the water solubility of PTX. Glu-PTX₂ NPs were characterized by electron microscopy and dynamic light scattering, exhibiting spherical morphology and favorable structural stability in aqueous media. Glu-PTX₂ NPs could be internalized by cancer cells as revealed by confocal laser scanning microscopy and exert potent cytotoxicity. It is envisaged that Glu-PTX₂ NPs would be an alternative formulation for PTX, and such amino acid linked drug dimers could also be applied to other therapeutic agents.

Denatured protein stabilized drug nanoparticles: tunable drug state and penetration across the intestinal barrier

Nanosuspensions of drugs are nanosized colloidal dispersions of pure particles. In contrast to conventional nanoparticles, the particles in nanosuspensions feature 100% drug loading. Stiripentol (STP) is an effective drug for severe myoclonic epilepsy of infancy (SMEI); however, because of its low water solubility, high oral doses of STP, up to 50 mg per kg per day in two or three divided doses, must be administered to patients, compromising therapy outcomes. Here, we report STP nanosuspensions (STP-Ns) stabilized with denatured soybean protein isolate (SPI) as a stabilizer to promote the absorption of STP and thus improve therapeutic outcomes. STP-Ns with a drug loading of up to 50% (w/w) and a diameter of 150 nm were successfully prepared. Importantly, in the presence of denatured SPI as a stabilizer, the drug state in the nanosuspensions was tunable by drug loading: low drug loading resulted in the formation of amorphous drug nanoparticles while high drug loading greater than 3.22% (w/w) in formulation induced the formation of nanosuspensions with the coexistence of amorphous and crystalline drug. This new nanosuspension formulation was related to the fact that the protein-drug complex exhibited a much stronger affinity for the drug particles over the protein itself. Interestingly, via the transcytosis pathway, the STP-Ns penetrated across the intestinal barrier into the systemic circulation, with the duodenum as the predominant absorption site. The bioavailability of the STP-Ns was 4-fold as great as that of raw crystals. The discovery of this mechanism for the use of globular protein as a stabilizer for nanosuspensions provides a new route for the preparation of amorphous drug nanoparticles. This work offers a new strategy to widen the application of globular protein and nanosuspensions of insoluble active compounds in drug delivery.

Facile fabrication of a magnetically smart PTX-loaded Cys–Fe3O4/CuS@BSA nano-drug for imaging-guided chemo-photothermal therapy

A PTX-loaded Cys-Fe₃O₄/CuS@BSA nano-drug was synthesized for MR and NIR imaging-guided chemo-photothermal combination therapy of cancer via a facile fabrication method.

Nanoprodrug of retinoic acid-modified paclitaxel

A nanoprodrug with high content (75%) and increased water solubility of paclitaxel was prepared from retinoic acid-modified paclitaxel.

Tumor-targeted nanomedicines for cancer theranostics

Chemotherapeutic drugs have multiple drawbacks, including severe side effects and suboptimal therapeutic efficacy. Nanomedicines assist in improving the biodistribution and target accumulation of chemotherapeutic drugs, and are therefore able to enhance the balance between efficacy and toxicity. Multiple types of nanomedicines have been evaluated over the years, including liposomes, polymer-drug conjugates and polymeric micelles, which rely on strategies such as passive targeting, active targeting and triggered release for improved tumor-directed drug delivery. Based on the notion that tumors and metastases are highly heterogeneous, it is important to integrate imaging properties in nanomedicine formulations in order to enable non-invasive and quantitative assessment of targeting efficiency. By allowing for patient pre-selection, such next generation nanotheranostics are useful for facilitating clinical translation and personalizing nanomedicine treatments.