Repurposing of Cetuximab in antibody-directed chemotherapy-loaded nanoparticles in EGFR therapy-resistant pancreatic tumours

Overcoming therapy resistance in pancreatic cancer: New insights and future directions

Pancreatic adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer deaths by 2030 and this is mostly due to therapy failure. Limited treatment options and resistance to standard-of-care (SoC) therapies makes PDAC one of the cancer types with poorest prognosis and survival rates [1,2]. Pancreatic tumors are renowned for their poor response to therapeutic interventions including targeted therapies, chemotherapy and radiotherapy. Herein, we review hallmarks of therapy resistance in PDAC and current strategies aiming to tackle escape mechanisms and to re-sensitize cancer cells to therapy. We will further provide insights on recent advances in the field of drug discovery, nanomedicine, and disease models that are setting the ground for future research.

Theranostic nanoparticles for detection and treatment of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most recalcitrant cancers due to its late diagnosis, poor therapeutic response, and highly heterogeneous microenvironment. Nanotechnology has the potential to overcome some of the challenges to improve diagnostics and tumor-specific drug delivery but they have not been plausibly viable in clinical settings. The review focuses on active targeting strategies to enhance pancreatic tumor-specific uptake for nanoparticles. Additionally, this review highlights using actively targeted liposomes, micelles, gold nanoparticles, silica nanoparticles, and iron oxide nanoparticles to improve pancreatic tumor targeting. Active targeting of nanoparticles toward either differentially expressed receptors or PDAC tumor microenvironment (TME) using peptides, antibodies, small molecules, polysaccharides, and hormones has been presented. We focus on microenvironment-based hallmarks of PDAC and the potential for actively targeted nanoparticles to overcome the challenges presented in PDAC. It describes the use of nanoparticles as contrast agents for improved diagnosis and the delivery of chemotherapeutic agents that target various aspects within the TME of PDAC. Additionally, we review emerging nano-contrast agents detected using imaging-based technologies and the role of nanoparticles in energy-based treatments of PDAC. This article is categorized under: Implantable Materials and Surgical Technologies > Nanoscale Tools and Techniques in Surgery Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Polymeric Nanoparticles for Drug Delivery

The recent emergence of nanomedicine has revolutionized the therapeutic landscape and necessitated the creation of more sophisticated drug delivery systems. Polymeric nanoparticles sit at the forefront of numerous promising drug delivery designs, due to their unmatched control over physiochemical properties such as size, shape, architecture, charge, and surface functionality. Furthermore, polymeric nanoparticles have the ability to navigate various biological barriers to precisely target specific sites within the body, encapsulate a diverse range of therapeutic cargo and efficiently release this cargo in response to internal and external stimuli. However, despite these remarkable advantages, the presence of polymeric nanoparticles in wider clinical application is minimal. This review will provide a comprehensive understanding of polymeric nanoparticles as drug delivery vehicles. The biological barriers affecting drug delivery will be outlined first, followed by a comprehensive description of the various nanoparticle designs and preparation methods, beginning with the polymers on which they are based. The review will meticulously explore the current performance of polymeric nanoparticles against a myriad of diseases including cancer, viral and bacterial infections, before finally evaluating the advantages and crucial challenges that will determine their wider clinical potential in the decades to come.

Bridging Smart Nanosystems with Clinically Relevant Models and Advanced Imaging for Precision Drug Delivery

Intracellular delivery of nano-drug-carriers (NDC) to specific cells, diseased regions, or solid tumors has entered the era of precision medicine that requires systematic knowledge of nano-biological interactions from multidisciplinary perspectives. To this end, this review first provides an overview of membrane-disruption methods such as electroporation, sonoporation, photoporation, microfluidic delivery, and microinjection with the merits of high-throughput and enhanced efficiency for in vitro NDC delivery. The impact of NDC characteristics including particle size, shape, charge, hydrophobicity, and elasticity on cellular uptake are elaborated and several types of NDC systems aiming for hierarchical targeting and delivery in vivo are reviewed. Emerging in vitro or ex vivo human/animal-derived pathophysiological models are further explored and highly recommended for use in NDC studies since they might mimic in vivo delivery features and fill the translational gaps from animals to humans. The exploration of modern microscopy techniques for precise nanoparticle (NP) tracking at the cellular, organ, and organismal levels informs the tailored development of NDCs for in vivo application and clinical translation. Overall, the review integrates the latest insights into smart nanosystem engineering, physiological models, imaging-based validation tools, all directed towards enhancing the precise and efficient intracellular delivery of NDCs.

Smart nanoparticles for cancer therapy

Smart nanoparticles, which can respond to biological cues or be guided by them, are emerging as a promising drug delivery platform for precise cancer treatment. The field of oncology, nanotechnology, and biomedicine has witnessed rapid progress, leading to innovative developments in smart nanoparticles for safer and more effective cancer therapy. In this review, we will highlight recent advancements in smart nanoparticles, including polymeric nanoparticles, dendrimers, micelles, liposomes, protein nanoparticles, cell membrane nanoparticles, mesoporous silica nanoparticles, gold nanoparticles, iron oxide nanoparticles, quantum dots, carbon nanotubes, black phosphorus, MOF nanoparticles, and others. We will focus on their classification, structures, synthesis, and intelligent features. These smart nanoparticles possess the ability to respond to various external and internal stimuli, such as enzymes, pH, temperature, optics, and magnetism, making them intelligent systems. Additionally, this review will explore the latest studies on tumor targeting by functionalizing the surfaces of smart nanoparticles with tumor-specific ligands like antibodies, peptides, transferrin, and folic acid. We will also summarize different types of drug delivery options, including small molecules, peptides, proteins, nucleic acids, and even living cells, for their potential use in cancer therapy. While the potential of smart nanoparticles is promising, we will also acknowledge the challenges and clinical prospects associated with their use. Finally, we will propose a blueprint that involves the use of artificial intelligence-powered nanoparticles in cancer treatment applications. By harnessing the potential of smart nanoparticles, this review aims to usher in a new era of precise and personalized cancer therapy, providing patients with individualized treatment options.

The Nanotechnology-Based Approaches against Kirsten Rat Sarcoma-Mutated Cancers

Kirsten rat sarcoma (KRAS) is a small GTPase which acts as a molecular switch to regulate several cell biological processes including cell survival, proliferation, and differentiation. Alterations in KRAS have been found in 25% of all human cancers, with pancreatic cancer (90%), colorectal cancer (45%), and lung cancer (35%) being the types of cancer with the highest mutation rates. KRAS oncogenic mutations are not only responsible for malignant cell transformation and tumor development but also related to poor prognosis, low survival rate, and resistance to chemotherapy. Although different strategies have been developed to specifically target this oncoprotein over the last few decades, almost all of them have failed, relying on the current therapeutic solutions to target proteins involved in the KRAS pathway using chemical or gene therapy. Nanomedicine can certainly bring a solution for the lack of specificity and effectiveness of anti-KRAS therapy. Therefore, nanoparticles of different natures are being developed to improve the therapeutic index of drugs, genetic material, and/or biomolecules and to allow their delivery specifically into the cells of interest. The present work aims to summarize the most recent advances related to the use of nanotechnology for the development of new therapeutic strategies against KRAS-mutated cancers.

Carbon Dots in Treatment of Pediatric Brain Tumors: Past, Present, and Future Directions

Pediatric brain tumors remain a significant source of morbidity and mortality. Though developments have been made in treating these malignancies, the blood-brain barrier, intra- and inter-tumoral heterogeneity, and therapeutic toxicity pose challenges to improving outcomes. Varying types of nanoparticles, including metallic, organic, and micellar molecules of varying structures and compositions, have been investigated as a potential therapy to circumvent some of these inherent challenges. Carbon dots (CDs) have recently gained popularity as a novel nanoparticle with theranostic properties. This carbon-based modality is highly modifiable, allowing for conjugation to drugs, as well as tumor-specific ligands in an effort to more effectively target cancerous cells and reduce peripheral toxicity. CDs are being studied pre-clinically. The ClinicalTrials.gov site was queried using the search terms: brain tumor and nanoparticle, liposome, micelle, dendrimer, quantum dot, or carbon dot. At the time of this review, 36 studies were found, 6 of which included pediatric patients. Two of the six studies investigated nanoparticle drug formulations, whereas the other four studies were on varying liposomal nanoparticle formulations for the treatment of pediatric brain tumors. Here, we reviewed the context of CDs within the broader realm of nanoparticles, their development, promising pre-clinical potential, and proposed future translational utility.

Targeting the 'Undruggable' Driver Protein, KRAS, in Epithelial Cancers: Current Perspective

This review summarizes recent development in synthetic drugs and biologics targeting intracellular driver genes in epithelial cancers, focusing on KRAS, and provides a current perspective and potential leads for the field. Compared to biologics, small molecule inhibitors (SMIs) readily penetrate cells, thus being able to target intracellular proteins. However, SMIs frequently suffer from pleiotropic effects, off-target cytotoxicity and invariably elicit resistance. In contrast, biologics are much larger molecules limited by cellular entry, but if this is surmounted, they may have more specific effects and less therapy-induced resistance. Exciting breakthroughs in the past two years include engineering of non-covalent KRAS G12D-specific inhibitor, probody bispecific antibodies, drug-peptide conjugate as MHC-restricted neoantigen to prompt immune response by T-cells, and success in the adoptive cell therapy front in both breast and pancreatic cancers.

Effects of morphology and size of nanoscale drug carriers on cellular uptake and internalization process: a review

In the field of targeted drug delivery, the effects of size and morphology of drug nanocarriers are of great importance and need to be discussed in depth. To be concise, among all the various shapes of nanocarriers, rods and tubes with a narrow cross-section are the most preferred shapes for the penetration of a cell membrane. In this regard, several studies have focused on methods to produce nanorods and nanotubes with controlled optimized size and aspect ratio (AR). Additionally, a non-spherical orientation could affect the cellular uptake process while a tangent angle of less than 45° is better at penetrating the membrane, and Ω = 90° is beneficial. Moreover, these nanocarriers show different behaviors when confronting diverse cells whose fields should be investigated in future studies. In this survey, a comprehensive classification based on carrier shape is first submitted. Then, the most commonly used methods for control over the size and shape of the carriers are reviewed. Finally, influential factors on the cellular uptake and internalization processes and related analytical methods for evaluating this process are discussed.

Design of Nanoparticles in Cancer Therapy Based on Tumor Microenvironment Properties

Cancer is one of the leading causes of death worldwide, and battling cancer has always been a challenging subject in medical sciences. All over the world, scientists from different fields of study try to gain a deeper knowledge about the biology and roots of cancer and, consequently, provide better strategies to fight against it. During the past few decades, nanoparticles (NPs) have attracted much attention for the delivery of therapeutic and diagnostic agents with high efficiency and reduced side effects in cancer treatment. Targeted and stimuli-sensitive nanoparticles have been widely studied for cancer therapy in recent years, and many more studies are ongoing. This review aims to provide a broad view of different nanoparticle systems with characteristics that allow them to target diverse properties of the tumor microenvironment (TME) from nanoparticles that can be activated and release their cargo due to the specific characteristics of the TME (such as low pH, redox, and hypoxia) to nanoparticles that can target different cellular and molecular targets of the present cell and molecules in the TME.

Quercetin improves pancreatic cancer chemo-sensitivity by regulating oxidative-inflammatory networks

Chemotherapy is the main method for controlling pancreatic cancer metastasis but the prevalent chemotherapy resistance limits its utilization. The response of oxidation and inflammation often promotes pancreatic cancer progression and chemo-resistance. It is critical to explore the potential natural products with few side effects to control inflammatory responses and understand the related mechanisms. Quercetin is a flavonoid widely found in numerous vegetables, fruits, and foods and is thought to have antioxidant and anti-inflammatory properties, which may be associated with improvement of chemotherapy sensitivity during pancreatic cancer treatment. Quercetin may sensitize pancreatic cancer cells to the chemotherapeutic agents, including bromodomain and extraterminal domain inhibitors (BETI), daunorubicin, gemcitabine, sulforaphane, doxorubicin, and tumor necrosis factor-related signaling apoptosis-inducing ligand (TRAIL). Meanwhile, during the chemo-resistance therapy, many signaling molecules are involved with toll-like receptor 4 (TLR4)-mediated oxidative and inflammatory pathway. The effects of quercetin on other oxidative and inflammatory pathways were also explored. Quercetin may exert antitumor activity during the prevention of pancreatic cancer progression by regulating oxidative and inflammatory networks, which can promote immune escape of cancer cells by inducing immunosuppressive cytokines. Studying these patterns will help us to better understand the functional role of quercetin in the improvement of pancreatic cancer chemo-sensitivity. PRACTICAL APPLICATIONS: Chemotherapy is the major way for treating pancreatic cancer metastasis but the prevalent chemotherapy resistance caused by oxidative and inflammatory responses limits its utilization. It is necessary to explore the potential natural products with few side effects to prevent the oxidative and inflammatory responses. Quercetin is a flavonoid widely found in numerous vegetables, fruits, and foods and is thought to have antioxidant and anti-inflammatory properties, which may be associated with improvement of chemotherapy sensitivity of pancreatic cancer treatment by sensitizing pancreatic cancer cells to various chemotherapeutic agents via the regulation of oxidative and inflammatory networks. Studying these patterns will help us to better understand the functional role of quercetin in the improvement of pancreatic cancer chemo-sensitivity.

Nanoparticle-based immunotherapy of pancreatic cancer

Pancreatic cancer (PC) has a complex and unique tumor microenvironment (TME). Due to the physical barrier formed by the desmoplastic stroma, the delivery of drugs to the tumor tissue is limited. The TME also contributes to resistance to various immunotherapies such as cancer vaccines, chimeric antigen receptor T cell therapy and immune checkpoint inhibitors. Overcoming and/or modulating the TME is therefore one of the greatest challenges in developing new therapeutic strategies for PC. Nanoparticles have been successfully used as drug carriers and delivery systems in cancer therapy. Recent experimental and engineering developments in nanotechnology have resulted in increased drug delivery and improved immunotherapy for PC. In this review we discuss and analyze the current nanoparticle-based immunotherapy approaches that are at the verge of clinical application. Particularly, we focus on nanoparticle-based delivery systems that improve the effectiveness of PC immunotherapy. We also highlight current clinical research that will help to develop new therapeutic strategies for PC and especially targeted immunotherapies based on immune checkpoint inhibitors.

Antibody-Based Approaches to Target Pancreatic Tumours

Pancreatic cancer is an aggressive cancer with a dismal prognosis. This is due to the difficulty to detect the disease at an early and curable stage. In addition, only limited treatment options are available, and they are confronted by mechanisms of resistance. Monoclonal antibody (mAb) molecules are highly specific biologics that can be directly used as a blocking agent or modified to deliver a drug payload depending on the desired outcome. They are widely used to target extracellular proteins, but they can also be employed to inhibit intracellular proteins, such as oncoproteins. While mAbs are a class of therapeutics that have been successfully employed to treat many cancers, they have shown only limited efficacy in pancreatic cancer as a monotherapy so far. In this review, we will discuss the challenges, opportunities and hopes to use mAbs for pancreatic cancer treatment, diagnostics and imagery.

Screening strategies for surface modification of lipid-polymer hybrid nanoparticles

Lipid-polymer hybrid nanoparticles are promising platforms in the field of targeted drug delivery, integrating the positive features of polymeric and lipid nanocarriers. However, the use of bulk procedures in lipid-polymer hybrid nanoparticles formulation is hindering their large-scale manufacturing. Therefore, the aim of this study is to explore the suitability of alternative formulation methods, such as microfluidics, to obtain surface-tunable nanoparticles displaying suitable characteristics. Formulations were prepared by single-step nanoprecipitation or using a micromixer chip. The nanocarriers were then surface-modified with an aptamer and an antibody, two common nanoparticle vectorization strategies, developing an optimized functionalization protocol. Both naked and surface-modified nanoparticles were characterized in terms of size, polydispersity, zeta potential and morphology. Moreover, the aptamer/antibody association efficiency was also determined. Nano-sized monodisperse nanoparticles, exhibiting a spherical core-shell structure, were obtained through both procedures. Furthermore, all the nanocarriers were successfully functionalized, showing association efficiency values above 70%. Interestingly, microfluidic-based nanoparticles displayed a smaller size and a more positive zeta potential than those prepared by single-step nanoprecipitation. Outcomes suggest both techniques led to lipid-polymer hybrid nanoparticles displaying a similar functionalization efficiency. Conversely, the microfluidic approach provided an improved control over critical parameters, as particle size or charge, constituting an interesting alternative to traditional formulation procedures.

Antibody-Incorporated Nanomedicines for Cancer Therapy

Antibody-based cancer therapy, one of the most significant therapeutic strategies, has achieved considerable success and progress over the past decades. Nevertheless, obstacles including limited tumor penetration, short circulation half-lives, undesired immunogenicity, and off-target side effects remain to be overcome for the antibody-based cancer treatment. Owing to the rapid development of nanotechnology, antibody-containing nanomedicines that have been extensively explored to overcome these obstacles have already demonstrated enhanced anticancer efficacy and clinical translation potential. This review intends to offer an overview of the advancements of antibody-incorporated nanoparticulate systems in cancer treatment, together with the nontrivial challenges faced by these next-generation nanomedicines. Diverse strategies of antibody immobilization, formats of antibodies, types of cancer-associated antigens, and anticancer mechanisms of antibody-containing nanomedicines are provided and discussed in this review, with an emphasis on the latest applications. The current limitations and future research directions on antibody-containing nanomedicines are also discussed from different perspectives to provide new insights into the construction of anticancer nanomedicines.

Leveraging self-assembled nanobiomaterials for improved cancer immunotherapy

Nanomaterials and targeted drug delivery vehicles improve the therapeutic index of drugs and permit greater control over their pharmacokinetics, biodistribution, and bioavailability. Here, nanotechnologies applied to cancer immunotherapy are discussed with a focus on current and next generation self-assembling drug delivery systems composed of lipids and/or polymers. Topics covered include the fundamental design, suitability, and inherent properties of nanomaterials that induce anti-tumor immune responses and support anti-cancer vaccination. Established active and passive targeting strategies as well as newer "indirect" methods are presented together with insights into how nanocarrier structure and surface chemistry can be leveraged for controlled delivery to the tumor microenvironment while minimizing off-target effects.

Orthogonal nanoarchitectonics of M13 phage for receptor targeted anticancer photodynamic therapy

Photodynamic therapy (PDT) represents a promising therapeutic modality for cancer. Here we used an orthogonal nanoarchitectonics approach (genetic/chemical) to engineer M13 bacteriophages as targeted vectors for efficient photodynamic killing of cancer cells. M13 was genetically refactored to display on the phage tip a peptide (SYPIPDT) able to bind the epidermal growth factor receptor (EGFR). The refactored M13_EGFR phages demonstrated EGFR-targeted tropism and were internalized by A431 cancer cells, that overexpress EGFR. Using an orthogonal approach to the genetic display, M13_EGFR phages were then chemically modified, conjugating hundreds of Rose Bengal (RB) photosensitizing molecules on the capsid surface, without affecting the selective recognition of the SYPIPDT peptides. Upon internalization, the M13_EGFR-RB derivatives generated intracellularly reactive oxygen species, activated by an ultralow intensity white light irradiation. The killing activity of cancer cells is observed at picomolar concentrations of the M13_EGFR phage.

Nanocarriers for pancreatic cancer imaging, treatments, and immunotherapies

Pancreatic tumors are highly desmoplastic and immunosuppressive. Delivery and distribution of drugs within pancreatic tumors are compromised due to intrinsic physical and biochemical stresses that lead to increased interstitial fluid pressure, vascular compression, and hypoxia. Immunotherapy-based approaches, including therapeutic vaccines, immune checkpoint inhibition, CAR-T cell therapy, and adoptive T cell therapies, are challenged by an immunosuppressive tumor microenvironment. Together, extensive fibrosis and immunosuppression present major challenges to developing treatments for pancreatic cancer. In this context, nanoparticles have been extensively studied as delivery platforms and adjuvants for cancer and other disease therapies. Recent advances in nanotechnology have led to the development of multiple nanocarrier-based formulations that not only improve drug delivery but also enhance immunotherapy-based approaches for pancreatic cancer. This review discusses and critically analyzes the novel nanoscale strategies that have been used for drug delivery and immunomodulation to improve treatment efficacy, including newly emerging immunotherapy-based approaches. This review also presents important perspectives on future research directions that will guide the rational design of novel and robust nanoscale platforms to treat pancreatic tumors, particularly with respect to targeted therapies and immunotherapies. These insights will inform the next generation of clinical treatments to help patients manage this debilitating disease and enhance survival rates.

Cetuximab-Polymersome-Mertansine Nanodrug for Potent and Targeted Therapy of EGFR-Positive Cancers

Targeted nanomedicines particularly armed with monoclonal antibodies are considered to be the most promising advanced chemotherapy for malignant cancers; however, their development is hindered by their instability and drug leakage problems. Herein, we constructed a robust cetuximab-polymersome-mertansine nanodrug (C-P-DM1) for highly potent and targeted therapy of epidermal growth factor receptor (EGFR)-positive solid tumors. C-P-DM1 with a tailored cetuximab surface density of 2 per P-DM1 exhibited a size of ca. 60 nm, high stability with minimum DM1 leakage, glutathione-triggered release of native DM1, and 6.0-11.3-fold stronger cytotoxicity in EGFR-positive human breast (MDA-MB-231), lung (A549), and liver (SMMC-7721) cancer cells (IC₅₀ = 27.1-135.5 nM) than P-DM1 control. Notably, intravenous injection of C-P-DM1 effectively repressed subcutaneous MDA-MB-231 breast cancer and orthotopic A549-Luc lung carcinoma in mice without inducing toxic effects. Strikingly, intratumoral injection of C-P-DM1 completely cured 60% of mice bearing breast tumor without recurrence. This robust cetuximab-polymersome-mertansine nanodrug provides a promising new strategy for targeted treatment of EGFR-positive solid malignancies.

Nanomedicine in Pancreatic Cancer: Current Status and Future Opportunities for Overcoming Therapy Resistance

Simple Summary

Despite access to a vast arsenal of anticancer agents, many fail to realise their full therapeutic potential in clinical practice. One key determinant of this is the evolution of multifaceted resistance mechanisms within the tumour that may either pre-exist or develop during the course of therapy. This is particularly evident in pancreatic cancer, where limited responses to treatment underlie dismal survival rates, highlighting the urgent need for new therapeutic approaches. Here, we discuss the major features of pancreatic tumours that contribute to therapy resistance, and how they may be alleviated through exploitation of the mounting and exciting promise of nanomedicines; a unique collection of nanoscale platforms with tunable and multifunctional capabilities that have already elicited a widespread impact on cancer management.

Abstract

The development of drug resistance remains one of the greatest clinical oncology challenges that can radically dampen the prospect of achieving complete and durable tumour control. Efforts to mitigate drug resistance are therefore of utmost importance, and nanotechnology is rapidly emerging for its potential to overcome such issues. Studies have showcased the ability of nanomedicines to bypass drug efflux pumps, counteract immune suppression, serve as radioenhancers, correct metabolic disturbances and elicit numerous other effects that collectively alleviate various mechanisms of tumour resistance. Much of this progress can be attributed to the remarkable benefits that nanoparticles offer as drug delivery vehicles, such as improvements in pharmacokinetics, protection against degradation and spatiotemporally controlled release kinetics. These attributes provide scope for precision targeting of drugs to tumours that can enhance sensitivity to treatment and have formed the basis for the successful clinical translation of multiple nanoformulations to date. In this review, we focus on the longstanding reputation of pancreatic cancer as one of the most difficult-to-treat malignancies where resistance plays a dominant role in therapy failure. We outline the mechanisms that contribute to the treatment-refractory nature of these tumours, and how they may be effectively addressed by harnessing the unique capabilities of nanomedicines. Moreover, we include a brief perspective on the likely future direction of nanotechnology in pancreatic cancer, discussing how efforts to develop multidrug formulations will guide the field further towards a therapeutic solution for these highly intractable tumours.

Enhanced target-specific delivery of docetaxel-loaded nanoparticles using engineered T cell receptors

For effective targeted therapy of cancer with chemotherapy-loaded nanoparticles (NPs), antigens that are selective for cancer cells should be targeted to minimise off-tumour toxicity. Human leukocyte antigens (HLAs) are attractive cancer targets as they can present peptides from tumour-selective proteins on the cell surface, which can be recognised by T cells via T cell receptors (TCRs). In this study, docetaxel-loaded polymeric NPs were conjugated to recombinant affinity-enhanced TCRs to target breast cancer cells presenting a tumour-selective peptide-HLA complex. The TCR-conjugated nanoparticles enabled enhanced delivery of docetaxel and induced cell death through tumour-specific peptide-HLA targeting. These in vitro data demonstrate the potential of targeting tumour-restricted peptide-HLA epitopes using high affinity TCR-conjugated nanoparticles, representing a novel treatment strategy to deliver therapeutic drugs specifically to cancer cells.

Nanomedicine to Overcome Multidrug Resistance Mechanisms in Colon and Pancreatic Cancer: Recent Progress

The development of drug resistance is one of the main causes of cancer treatment failure. This phenomenon occurs very frequently in different types of cancer, including colon and pancreatic cancers. However, the underlying molecular mechanisms are not fully understood. In recent years, nanomedicine has improved the delivery and efficacy of drugs, and has decreased their side effects. In addition, it has allowed to design drugs capable of avoiding certain resistance mechanisms of tumors. In this article, we review the main resistance mechanisms in colon and pancreatic cancers, along with the most relevant strategies offered by nanodrugs to overcome this obstacle. These strategies include the inhibition of efflux pumps, the use of specific targets, the development of nanomedicines affecting the environment of cancer-specific tissues, the modulation of DNA repair mechanisms or RNA (miRNA), and specific approaches to damage cancer stem cells, among others. This review aims to illustrate how advanced nanoformulations, including polymeric conjugates, micelles, dendrimers, liposomes, metallic and carbon-based nanoparticles, are allowing to overcome one of the main limitations in the treatment of colon and pancreatic cancers. The future development of nanomedicine opens new horizons for cancer treatment.

Ligand decorated biodegradable nanomedicine in the treatment of cancer

Cancer is one of the major global health problems, responsible for the second-highest number of deaths. The genetic and epigenetic changes in the oncogenes or tumor suppressor genes alter the regulatory pathways leading to its onset and progression. Conventional methods are used in appropriate combinations for the treatment. Surgery effectively treats localized tumors; however, it fails to treat metastatic tumors, leading to a spread in other organs, causing a high recurrence rate and death. Among the different strategies, the nanocarriers-based approach is highly sought for, but its nonspecific delivery can cause a profound side effect on healthy cells. Targeted nanomedicine has the advantage of targeting cancer cells specifically by interacting with the receptors overexpressed on their surface, overcoming its non-specificity to target healthy cells. Nanocarriers prepared from biodegradable and biocompatible materials are decorated with different ligands by encapsulating therapeutic or diagnostic agents or both to target cancer cells overexpressing the receptors. Scientists are now utilizing a theranostic approach to simultaneously evaluate nanocarrier bio-distribution and its effect on the treatment regime. Herein, we have summarized the recent 5-year efforts in the development of the ligands decorated biodegradable nanocarriers, as a targeted nanomedicine approach, which has been highly promising in the treatment of cancer.

Nanoparticle Surface Functionalization: How to Improve Biocompatibility and Cellular Internalization

The use of nanoparticles (NP) in diagnosis and treatment of many human diseases, including cancer, is of increasing interest. However, cytotoxic effects of NPs on cells and the uptake efficiency significantly limit their use in clinical practice. The physico-chemical properties of NPs including surface composition, superficial charge, size and shape are considered the key factors that affect the biocompatibility and uptake efficiency of these nanoplatforms. Thanks to the possibility of modifying physico-chemical properties of NPs, it is possible to improve their biocompatibility and uptake efficiency through the functionalization of the NP surface. In this review, we summarize some of the most recent studies in which NP surface modification enhances biocompatibility and uptake. Furthermore, the most used techniques used to assess biocompatibility and uptake are also reported.

EGFR targeting for cancer therapy: Pharmacology and immunoconjugates with drugs and nanoparticles

The epidermal growth factor receptor (EGFR) belongs to the tyrosine kinase receptors family and is present in the epithelial cell membrane. Its endogenous activation occurs through the binding of different endogenous ligands, including the epidermal growth factor (EGF), leading to signaling cascades able to maintain normal cellular functions. Although involved in the development and maintenance of tissues in normal conditions, when EGFR is overexpressed, it stimulates the growth and progression of tumors, resulting in angiogenesis, invasion and metastasis, through some main cascades such as Ras/Raf/MAPK, PIK-3/AKT, PLC-PKC and STAT. Besides, considering the limitations of conventional chemotherapy that result in high toxicity and low tumor specificity, EGFR is currently considered an important target. As a result, several monoclonal antibodies are currently approved for use in cancer treatment, such as cetuximab (CTX), panitumumab, nimotuzumab, necitumumab and others are in clinical trials. Aiming to combine the chemotherapeutic agent toxicity and specific targeting to EGFR overexpressing tumor tissues, two main strategies will be discussed in this review: antibody-drug conjugates (ADCs) and antibody-nanoparticle conjugates (ANCs). Briefly, ADCs consist of antibodies covalently linked through a spacer to the cytotoxic drug. Upon administration, binding to EGFR and endocytosis, ADCs suffer chemical and enzymatic reactions leading to the release and accumulation of the drug. Instead, ANCs consist of nanotechnology-based formulations, such as lipid, polymeric and inorganic nanoparticles able to protect the drug against inactivation, allowing controlled release and also passive accumulation in tumor tissues by the enhanced permeability and retention effect (EPR). Furthermore, ANCs undergo active targeting through EGFR receptor-mediated endocytosis, leading to the formation of lysosomes and drug release into the cytosol. Herein, we will present and discuss some important aspects regarding EGFR structure, its role on internal signaling pathways and downregulation aspects. Then, considering that EGFR is a potential therapeutic target for cancer therapy, the monoclonal antibodies able to target this receptor will be presented and discussed. Finally, ADCs and ANCs state of the art will be reviewed and recent studies and clinical progresses will be highlighted. To the best of our knowledge, this is the first review paper to address specifically the EGFR target and its application on ADCs and ANCs.

EGLIF-CAR-T Cells Secreting PD-1 Blocking Antibodies Significantly Mediate the Elimination of Gastric Cancer

Objective

To investigate the anti-tumor effects of programmed cell death protein 1 (PD-1) scFv-secreting EGFR-chimeric antigen receptor-modified (CAR)-T cells against gastric cancer.

Methods

Second-generation EGFR-CAR-T cells and fourth-generation PD-1 scFv-secreting EGFR-CAR-T cells were engineered. The anti-tumor activities of chimeric antigen receptor-modified (CAR)-T cells were analyzed in vitro by long-term co-culture with gastric cancer cells. The tumor scavenging capacity in vivo was evaluated in xenograft and PDX mouse models.

Results

EGFR-CAR-T cells secreting PD-1 scFv showed enhanced long-term tumor cell killing capacity in vitro. These cells also showed significant anti-tumor effect in the subcutaneous xenograft model of gastric cancer as well as in the PDX model, and autocrine PD-1 antibody secretion significantly increased tumor infiltration of the CAR-T cells.

Conclusion

EGFR-CAR-T cells secreting PD-1 scFv are highly effective against gastric cancer and offer new insights into anti-cancer immunotherapy.

Surface-functionalised hybrid nanoparticles for targeted treatment of cancer

Cancer is a leading cause of death worldwide. Despite the great advancement in understanding the pharmacology and biology of cancer, it still signifies one of the most serious human-health related problems. The current treatments for cancer may include surgery, radiotherapy, and chemotherapy, but these procedures have several limitations. Current studies have shown that nanoparticles (NPs) can be used as a novel strategy for cancer treatment. Developing nanosystems that allow lower doses of therapeutic agents, as well as their selective release in tumour cells, may resolve the challenges of targeted cancer therapy. In this review, the authors discuss the role of the size, shape, and surface modifications of NPs in cancer treatment. They also address the challenges associated with cancer therapies based on NPs. The overall purpose of this review is to summarise the recent developments in designing different hybrid NPs with promising therapeutic properties for different types of cancer.

DR5-targeted, chemotherapeutic drug-loaded nanoparticles induce apoptosis and tumor regression in pancreatic cancer in vivo models

Pancreatic cancer is usually advanced and drug resistant at diagnosis. A potential therapeutic approach outlined here uses nanoparticle (NP)-based drug carriers, which have unique properties that enhance intra-tumor drug exposure and reduce systemic toxicity of encapsulated drugs. Here we report that patients whose pancreatic cancers express elevated levels of Death Receptor 5 (DR5) and its downstream regulators/effectors FLIP, Caspase-8, and FADD had particularly poor prognoses. To take advantage of elevated expression of this pathway, we designed drug-loaded NPs with a surface-conjugated αDR5 antibody (AMG 655). Binding and clustering of the DR5 is a prerequisite for efficient apoptosis initiation, and the αDR5-NPs were indeed found to activate apoptosis in multiple pancreatic cancer models, whereas the free antibody did not. The extent of apoptosis induced by αDR5-NPs was enhanced by down-regulating FLIP, a key modulator of death receptor-mediated activation of caspase-8. Moreover, the DNA topoisomerase-1 inhibitor camptothecin (CPT) down-regulated FLIP in pancreatic cancer models and enhanced apoptosis induced by αDR5-NPs. CPT-loaded αDR5-NPs significantly increased apoptosis and decreased cell viability in vitro in a caspase-8- and FADD-dependent manner consistent with their expected mechanism-of-action. Importantly, CPT-loaded αDR5-NPs markedly reduced tumor growth rates in vivo in established pancreatic tumor models, inducing regressions in one model. These proof-of-concept studies indicate that αDR5-NPs loaded with agents that downregulate or inhibit FLIP are promising candidate agents for the treatment of pancreatic cancer.

Refined construction of antibody-targeted nanoparticles leads to superior antigen binding and enhanced delivery of an entrapped payload to pancreatic cancer cells

Antibody-targeted nanoparticles have shown exceptional promise as delivery vehicles for anticancer drugs, although manufacturability challenges have hampered clinical progress. These include the potential for uncontrolled and random antibody conjugation, resulting in masked or inactive paratopes and unwanted Fc domain interactions. To circumvent these issues, we show that the interchain disulfide of cetuximab F(ab) may be selectively re-bridged with a strained alkyne handle, to permit 'click' coupling to azide-capped nanoparticles in a highly uniform and oriented manner. When compared to conventional carbodiimide chemistry, this conjugation approach leads to the generation of nanoparticles with a higher surface loading of cetuximab F(ab) and with markedly improved ability to bind to the target epidermal growth factor receptor. Moreover, we show that entrapment of a camptothecin payload within these nanoparticles can enhance drug targeting to antigen-expressing pancreatic cancer cells, resulting in superior cytotoxicity versus the conventional nanoformulation. Collectively, this work highlights the critical need to develop refined methods for the construction of targeted nanoparticles that will accelerate their clinical translation through improved performance and manufacturability.

Inhibitory effects of brusatol delivered using glycosaminoglycan‑placental chondroitin sulfate A‑modified nanoparticles on the proliferation, migration and invasion of cancer cells

Breakthroughs in cancer management result from the development of drugs that can be used for early diagnosis and effective treatment. Surgery, chemotherapy, radiotherapy and hormone therapy are the main anticancer therapies. However, traditional cancer chemotherapy is associated with serious systemic side effects. Nanoparticles (NPs) provide an effective solution for cancer treatment via the targeted delivery of drugs to cancer cells, while minimizing injury to normal cells. Glycosaminoglycan-placental chondroitin sulfate A (plCSA) is expressed in a number of tumor cells and trophoblasts. A plCSA-binding peptide (plCSA-BP) was isolated from malaria protein VAR2CSA, which can effectively promote the binding of lipid polymer NPs to tumor cells, thereby significantly enhancing the anticancer effect of encapsulated drugs. Brusatol is an important compound derived from Brucea javanica that exerts a multitude of biological effects, including inhibiting tumor cell growth, reducing the reproduction of malaria parasites, reducing inflammation and resisting virus invasion. In the present study, brusatol-loaded NPs (BNPs) or coumarin 6 NPs (CNPs), plCSA-BP and scrambled control peptide-bound BNPs or CNPs were prepared. Ovarian cancer cells (SKOV3), endometrial cancer cells (HEC-1-A) and lung cancer cells (A549) were treated with the NPs. The uptake of plCSA-CNPs by tumor cells was found to be markedly higher compared with that of other types of NPs. Further studies demonstrated that the plCSA-BNPs promoted the apoptosis of cancer cells more effectively and inhibited their proliferation, invasion and migration, accompanied by downregulation of matrix metalloproteinase (MMP)-2, MMP-9 and B-cell CLL/lymphoma 2 (BCL2) levels, but upregulation of BCL2-associated X protein BAX and cleaved caspase-3 levels. The results demonstrated the potential of brusatol delivered by plCSA-modified NPs as a chemotherapeutic agent for the targeted therapy of tumors by regulating the BCL2, BAX, cleaved caspase-3, MMP-2 and MMP-9 pathways, and indicated that it may be an effective and safe strategy for the treatment of various tumors.