Erythrocyte membrane-camouflaged gefitinib/albumin nanoparticles for tumor imaging and targeted therapy against lung cancer

Unravelling the role of tumor microenvironment responsive nanobiomaterials in spatiotemporal controlled drug delivery for lung cancer therapy

Design and development of efficient drug delivery technologies that impart site-specificity is the need of the hour for the effective treatment of lung cancer. The emergence of materials science and nanotechnology partially helped drug delivery scientists to achieve this objective. Various stimuli-responsive materials that undergo degradation at the pathological tumor microenvironment (TME) have been developed and explored for drug delivery applications using nanotechnological approaches. Nanoparticles (NPs), owing to their small size and high surface area to volume ratio, demonstrated enhanced cellular internalization, permeation, and retention at the tumor site. Such passive accumulation of stimuli-responsive materials helped to achieve spatiotemporally controlled and targeted drug delivery within the tumors. In this review, we discussed various stimuli-physical (interstitial pressure, temperature, and stiffness), chemical (pH, hypoxia, oxidative stress, and redox state), and biological (receptor expression, efflux transporters, immune cells, and their receptors or ligands)-that are characteristic to the TME. We mentioned an array of biomaterials-based nanoparticulate delivery systems that respond to these stimuli and control drug release at the TME. Further, we discussed nanoparticle-based combinatorial drug delivery strategies. Finally, we presented our perspectives on challenges related to scale-up, clinical translation, and regulatory approvals.

Albumin Nanoparticle-Based Drug Delivery Systems

Nanoparticle-based systems are extensively investigated for drug delivery. Among others, with superior biocompatibility and enhanced targeting capacity, albumin appears to be a promising carrier for drug delivery. Albumin nanoparticles are highly favored in many disease therapies, as they have the proper chemical groups for modification, cell-binding sites for cell adhesion, and affinity to protein drugs for nanocomplex generation. Herein, this review summarizes the recent fabrication techniques, modification strategies, and application of albumin nanoparticles. We first discuss various albumin nanoparticle fabrication methods, from both pros and cons. Then, we provide a comprehensive introduction to the modification section, including organic albumin nanoparticles, metal albumin nanoparticles, inorganic albumin nanoparticles, and albumin nanoparticle-based hybrids. We finally bring further perspectives on albumin nanoparticles used for various critical diseases.

Red blood cells based nanotheranostics: A smart biomimetic approach for fighting against cancer

The technique of engineering drug delivery vehicles continues to develop, which bring enhancements in working more efficiently and minimizing side effects to make it more effective and safer. The intense capability of therapeutic agents to remain undamaged in a harsh extracellular environment is helpful to the success of drug development efforts. With this in mind, alterations of biopharmaceuticals with enhanced stability and decreased immunogenicity have been an increasingly active focus of such efforts. Red blood cells (RBCs), also known as erythrocytes have undergone extensive scrutiny as potential vehicles for drug delivery due to their remarkable attributes over the years of research. These include intrinsic biocompatibility, minimal immunogenicity, flexibility, and prolonged systemic circulation. Throughout the course of investigation, a diverse array of drug delivery platforms based on RBCs has emerged. These encompass genetically engineered RBCs, non-genetically modified RBCs, and RBC membrane-coated nanoparticles, each devised to cater to a range of biomedical objectives. Given their prevalence in the circulatory system, RBCs have gained significant attention for their potential to serve as biomimetic coatings for artificial nanocarriers. By virtue of their surface emulation capabilities and customizable core materials, nanocarriers mimicking these RBCs, hold considerable promise across a spectrum of applications, spanning drug delivery, imaging, phototherapy, immunomodulation, sensing, and detection. These multifaceted functionalities underscore the considerable therapeutic and diagnostic potential across various diseases. Our proposed review provides the synthesis of recent strides in the theranostic utilization of erythrocytes in the context of cancer. It also delves into the principal challenges and prospects intrinsic to this realm of research. The focal point of this review pertains to accentuating the significance of erythrocyte-based theranostic systems in combating cancer. Furthermore, it precisely records the latest and the most specific methodologies for tailoring the attributes of these biomimetic nanoscale formulations, attenuating various discoveries for the treatment and management of cancer.

Bioengineered Abiotic Nanomaterials Through Cell Membrane-Camouflaging: Advancements and Challenges in Lung Cancer

Lung cancer remains a major global health concern with high mortality rates and poor prognosis. Bridging the gap between the chemical and cellular understanding of cell-decorated biomimetic nanocomposites and their clinical translation is crucial for developing effective therapies. Nanocomposites show promise in targeted drug delivery and diagnostics, but their clinical application is hindered by biocompatibility and clearance issues. To overcome these challenges, biomimetic approaches utilizing cell membrane-coated nanomaterials emerge. By camouflaging nanomaterials with cell membranes, the biointerfaces are enhanced, and the inherent properties of the donor cell membranes are acquired. This review provides an overview of recent advancements on cell membrane-coated nanocomposites for lung cancer diagnosis and treatment. It discusses fabrication techniques, biomedical applications, challenges, and future prospects. The incorporation of cell membranes into nanocomposites holds potential for improved lung cancer therapy, but further development and refinement are needed for precise tumor targeting. Addressing the identified challenges will pave the way for clinical translation of these biomimetic nanoplatforms and advance lung cancer diagnosis and treatment.

New insights into red blood cells in tumor precision diagnosis and treatment

Red blood cells (RBCs), which function as material transporters in organisms, are rich in materials that are exchanged with metabolically active tumor cells. Recent studies have demonstrated that tumor cells can regulate biological changes in RBCs, including influencing differentiation, maturation, and morphology. RBCs play an important role in tumor development and immune regulation. Notably, the novel scientific finding that RBCs absorb fragments of tumor-carrying DNA overturns the conventional wisdom that RBCs do not contain nucleic acids. RBC membranes are excellent biomimetic materials with significant advantages in terms of their biocompatibility, non-immunogenicity, non-specific adsorption resistance, and biodegradability. Therefore, RBCs provide a new research perspective for the development of tumor liquid biopsies, molecular imaging, drug delivery, and other tumor precision diagnosis and treatment technologies.

Biomimetic Cancer-Targeting Nanoplatform Boosting AIEgens-Based Photodynamic Therapy and Ferroptosis by Disrupting Redox-Homeostasis

Photodynamic therapy (PDT) using aggregation-induced emission photosensitizer (AIE-PS) holds tremendous potential but is limited by its inherent disadvantages and the high concentrations of reduced glutathione (GSH) in tumor cells that can neutralize ROS to weaken PDT. Herein, we designed a nanodelivery system (CM-HSADSP@[PS-Sor]) in which albumin was utilized as a carrier for hydrophobic drug AIE-PS and Sorafenib, cross-linkers with disulfide bonds were introduced to form a nanogel core, and then cancer cell membranes were wrapped on its surface to confer homologous tumor targeting ability. A two-way strategy was employed to disturb redox-homeostasis through blocking GSH synthesis by Sorafenib and consuming excess GSH via abundant disulfide bonds, thereby promoting the depletion of GSH, which in turn increased the ROS levels in cancer cells to amplify the efficacy of ferroptosis and PDT, achieving an efficient in vivo antibreast cancer effect. This study brings a new strategy for ROS-based cancer therapy and expands the application of an albumin-based drug delivery system.

Clinical Practice of Photodynamic Therapy for Non-Small Cell Lung Cancer in Different Scenarios: Who Is the Better Candidate?

BACKGROUND

Photodynamic therapy (PDT) is a relatively safe and highly selectivity antitumor treatment, which might be increasingly used as a supplement to conventional therapies. A clinical overview and detailed comparison of how to select patients and lesions for PDT in different scenarios are urgently needed to provide a basis for clinical treatment.

SUMMARY

This review demonstrates the highlights and obstacles of applying PDT for lung cancer and underlines points worth considering when planning to initiate PDT. The aim was to make out the appropriate selection and help PDT develop efficacy and precision through a better understanding of its clinical use.

KEY MESSAGES

Increasing evidence supports the feasibility and safety of PDT in the treatment of non-small cell lung cancer. It is important to recognize the factors that influence the efficacy of PDT to develop individualized management strategies and implement well-designed procedures. These important issues should be worth considering in the present and further research.

Advances in Targeting Drug Biological Carriers for Enhancing Tumor Therapy Efficacy

Chemotherapy drugs continue to be the main component of oncology treatment research and have been proven to be the main treatment modality in tumor therapy. However, the poor delivery efficiency of cancer therapeutic drugs and their potential off-target toxicity significantly limit their effectiveness and extensive application. The recent integration of biological carriers and functional agents is expected to camouflage synthetic biomimetic nanoparticles for targeted delivery. The promising candidates, including but not limited to red blood cells and their membranes, platelets, tumor cell membrane, bacteria, immune cell membrane, and hybrid membrane are typical representatives of biological carriers because of their excellent biocompatibility and biodegradability. Biological carriers are widely used to deliver chemotherapy drugs to improve the effectiveness of drug delivery and therapeutic efficacy in vivo, and tremendous progress is made in this field. This review summarizes recent developments in biological vectors as targeted drug delivery systems based on microenvironmental stimuli-responsive release, thus highlighting the potential applications of target drug biological carriers. The review also discusses the possibility of clinical translation, as well as the exploitation trend of these target drug biological carriers.

Modified gefitinib conjugated Fe3O4 NPs for improved delivery of chemo drugs following an image-guided mechanistic study of inner vs. outer tumor uptake for the treatment of non-small cell lung cancer

Gefitinib (GEF) is an FDA-approved anti-cancer drug for the first-line treatment of patients with metastatic non-small cell lung cancer (NSCLC). However, the efficacy of anticancer drugs is limited due to their non-specificity, lower accumulation at target sites, and systemic toxicity. Herein, we successfully synthesized a modified GEF (mGEF) drug and conjugated to Iron oxide nanoparticles (Fe3O4 NPs) for the treatment of NSCLC via magnetic resonance (MR) image-guided drug delivery. A traditional EDC coupling pathway uses mGEF to directly conjugate to Fe3O4 NPs to overcom the drug leakage issues. As a result, we found in vitro drug delivery on mGEF- Fe3O4 NPs exhibits excellent anticancer effects towards the PC9 cells selectively, with an estimated IC 50 value of 2.0 μM. Additionally, in vivo MRI and PET results demonstrate that the NPs could accumulate in tumor-specific regions with localized cell growth inhibition. Results also revealed that outer tumor region exhibiting a stronger contrast than the tinner tumor region which may due necrosis in inner tumor region. In vivo biodistribution further confirms Fe3O4 NPs are more biocompatible and are excreated after the treatment. Overall, we believe that this current strategy of drug modification combined with chemical conjugation on magnetic NPs will lead to improved cancer chemotherapy as well as understanding the tumor microenvironments for better therapeutic outcomes.

Circular Dichroism as a Rapid Method for Analyzing the Binding of a Targeting Ligand to the Surface of Albumin Nanoparticles

Circular dichroism (CD) is an excellent and rapid method for analysis of chiral molecules, whose mechanism is based on the absorption of left- and right-hand circularly polarized light. Albumin nanoparticles are biocompatible and easy to modify due to their structure. Tumor cell membranes are among the molecules that direct nanoparticles into the tumor microenvironment, but methods to study them except molecular biology are not well validated yet. The aim of this study was to use circular dichroism as the tool to qualitatively assess ligand binding on the surface of nanoparticles. Human serum albumin (HSA) nanoparticles with encapsulated 5-fluorouracil (5-FU) were coated on MCF-7 cell membranes and subjected to CD analysis. This study was completed using sample and separate 5-FU release analysis. The amount of encapsulated drug in nanoparticles affects the binding of cell membranes on the nanoparticle surface. In addition, it can be suspected that the alpha structure of HSA was mainly used for the interaction, which confirms the effectiveness of using CD as a rapid technique for analyzing ligand-nanoparticle interactions. The release of 5-FU from the nanoparticles proceeds in an uncontrolled manner, making this study in need of further modification and investigation.

The role of protein corona on nanodrugs for organ-targeting and its prospects of application

Nowadays, nanodrugs become a hotspot in the high-end medical field. They have the ability to deliver drugs to reach their destination more effectively due to their unique properties and flexible functionalization. However, the fate of nanodrugs in vivo is not the same as those presented in vitro, which indeed influenced their therapeutic efficacy in vivo. When entering the biological organism, nanodrugs will first come into contact with biological fluids and then be covered by some biomacromolecules, especially proteins. The proteins adsorbed on the surface of nanodrugs are known as protein corona (PC), which causes the loss of prospective organ-targeting abilities. Fortunately, the reasonable utilization of PC may determine the organ-targeting efficiency of systemically administered nanodrugs based on the diverse expression of receptors on cells in different organs. In addition, the nanodrugs for local administration targeting diverse lesion sites will also form unique PC, which plays an important role in the therapeutic effect of nanodrugs. This article introduced the formation of PC on the surface of nanodrugs and summarized the recent studies about the roles of diversified proteins adsorbed on nanodrugs and relevant protein for organ-targeting receptor through different administration pathways, which may deepen our understanding of the role that PC played on organ-targeting and improve the therapeutic efficacy of nanodrugs to promote their clinical translation.

Recent advancement on albumin nanoparticles in treating lung carcinoma

With the advancement of nanotechnology, many different forms of nanoparticles (NPs) are created, which specifically enhance anticancer drug delivery to tumor cells. Albumin bio-macromolecule is a flexible protein carrier for the delivery of drugs that is biodegradable, biocompatible, and non-toxic. As a result, it presents itself as an ideal material for developing nanoparticles for anticancer drug delivery. Toxicological investigations demonstrated that this novel drug delivery technique is safe for use in the human population. Furthermore, drug compatibility with the albumin nanoparticle is remarkable. The robust structure of the nanoparticle, high drug encapsulation, and customizable drug release make it a promising carrier option for the treatment of lung cancer. In this review, we summarize human serum albumin and bovine serum albumin in the targeted delivery of anticancer drugs to lung cancer cells.

Nanotechnology-empowered lung cancer therapy: From EMT role in cancer metastasis to application of nanoengineered structures for modulating growth and metastasis

Lung cancer is one of the leading causes of death in both males and females, and it is the first causes of cancer-related deaths. Chemotherapy, surgery and radiotherapy are conventional treatment of lung cancer and recently, immunotherapy has been also appeared as another therapeutic strategy for lung tumor. However, since previous treatments have not been successful in cancer therapy and improving prognosis and survival rate of lung tumor patients, new studies have focused on gene therapy and targeting underlying molecular pathways involved in lung cancer progression. Nanoparticles have been emerged in treatment of lung cancer that can mediate targeted delivery of drugs and genes. Nanoparticles protect drugs and genes against unexpected interactions in blood circulation and improve their circulation time. Nanoparticles can induce phototherapy in lung cancer ablation and mediating cell death. Nanoparticles can induce photothermal and photodynamic therapy in lung cancer. The nanostructures can impair metastasis of lung cancer and suppress EMT in improving drug sensitivity. Metastasis is one of the drawbacks observed in lung cancer that promotes migration of tumor cells and allows them to establish new colony in secondary site. EMT can occur in lung cancer and promotes tumor invasion. EMT is not certain to lung cancer and it can be observed in other human cancers, but since lung cancer has highest incidence rate, understanding EMT function in lung cancer is beneficial in improving prognosis of patients. EMT induction in lung cancer promotes tumor invasion and it can also lead to drug resistance and radio-resistance. Moreover, non-coding RNAs and pharmacological compounds can regulate EMT in lung cancer and EMT-TFs such as Twist and Slug are important modulators of lung cancer invasion that are discussed in current review.

The therapeutic effect of PEI-Fe3O4/pYr-ads-8-5HRE-cfosp-IFNG albumin nanospheres combined with magnetic fluid hyperthermia on hepatoma

Background

Hepatocellular carcinoma (HCC) is one of the most prevalent and deadly malignant tumors with serious clinical and socioeconomic consequences. Although gene therapy holds great promise in the treatment of hepatoma, its clinical applications are hindered by uncontrolled gene transmission and transcription.

Methods

The pY-ads-8-5HRE-cfosp-IFNG plasmid was constructed and identified by double enzyme digestion and gene sequencing. The expression of pYr-ads-8-5HRE-cfosp-IFNG in HepG2 cells was detected by quantitative PCR. PEI-Fe3O4/pYr-ads-8-5HRE-cfosp-IFNG albumin nanospheres were prepared and characterized. In vitro heating test of magnetic albumin nanospheres in an alternating magnetic field (AMF) was carried out. The therapeutic effect of PEI-Fe3O4/pYr-ads-8-5HRE-cfosp-IFNG albumin nanospheres on hepatocellular carcinoma was investigated by cell and animal experiments. After treatment, mice blood was collected for clinical biochemical analysis and histopathological evaluation of major organs was performed to assess potential adverse effects of treatment.

Results

Double enzyme digestion and gene sequencing showed that the pY-ads-8-5HRE-cfosp-IFNG plasmid was constructed successfully. QPCR results showed that the IFNγ transcript level in the PEI-Fe3O4/pYr-ads-8-5HRE-cfosp-IFNG group was higher than that in the PEI-Fe3O4/pYr-ads-8-cfosp-IFNG group after being treated with hypoxia (P<0.05). TEM revealed that the self-prepared PEI-Fe3O4/pYr-ads-8-5HRE-cfosp-IFNG albumin nanospheres exhibit an approximately spherical or elliptical shape. The hydrodynamic size of the albumin nanospheres was 139.7 nm. The maximum temperature of 0.25 mg/mL solution is stable at about 44°C, which is suitable for tumor thermal therapy without damaging normal tissues. The relative cell inhibition rate of the radiation-gene therapy and MFH combination group was higher than that of other control groups in CCK8 experiment. (P<0.05) Flow cytometry showed that the apoptosis rate and necrosis rate of the combined treatment group were 42.32% and 35.73%, respectively, higher than those of the other groups. (P<0.05) In animal experiments, the mass and volume inhibition rates of the combined treatment group were 66.67% and 72.53%, respectively, higher than those of other control groups. (P<0.05) Clinical biochemical analysis and histopathological evaluation showed no abnormality.

Conclusions

The results indicated the successful construction of the radiation-induced plasmid and demonstrated that the hypoxia enhancer could augment the expression of INFγ in a hypoxia environment. Gene therapy combined with magnetic fluid hyperthermia (MFH) has exhibited excellent outcomes in both cell and animal studies. Our experiments demonstrated that the PEI-Fe3O4/pYr-ads-8-5HRE-cfosp-IFNG albumin nanospheres system is a comprehensive treatment method for hepatoma, which can effectively combine immune genre therapy with hyperthermia.

Biomimetic nanovaccine based on erythrocyte membrane enhances immune response and protection against tilapia lake virus

An infectious disease emerged in recent years, Tilapia Lake Virus Disease (TiLVD), has severely restricted the development of global tilapia industry. Vaccination has proved potential strategy to prevent its causative agent Tilapia Lake Virus (TiLV) infectious. However, the response intensity of subunit vaccine is limited by its low immunogenicity, thus inclusion of adjuvants is required. Thus, we prepared a biomimetic nano-system (Cs-S2@M-M) with a particle size of ∼100 nm and an encapsulation efficiency of about 79.15% based on erythrocyte membrane. The immune response was detected after intramuscular injection to assess the effectiveness of the vaccine. The biomimetic system significantly up-regulates the expression of immune genes, enhances the activity of non-specific immune-related enzymes (P < 0.05) and improved relative percentage survival by 17.4%-26.1% in TiLV challenge. The biomimetic nano-system based on erythrocyte membrane induced significant immune response in tilapia and enhanced protection against TiLV, promising as a model for fish vaccines.

Recent Advances in Boosting EGFR Tyrosine Kinase Inhibitors-Based Cancer Therapy

Epidermal growth factor receptor (EGFR) plays a key role in signal transduction pathways associated with cell proliferation, growth, and survival. Its overexpression and aberrant activation in malignancy correlate with poor prognosis and short survival. Targeting inhibition of EGFR by small-molecular tyrosine kinase inhibitors (TKIs) is emerging as an important treatment model besides of chemotherapy, greatly reshaping the landscape of cancer therapy. However, they are still challenged by the off-targeted toxicity, relatively limited cancer types, and drug resistance after long-term therapy. In this review, we summarize the recent progress of oral, pulmonary, and injectable drug delivery systems for enhanced and targeting TKI delivery to tumors and reduced side effects. Importantly, EGFR-TKI-based combination therapies not only greatly broaden the applicable cancer types of EGFR-TKI but also significantly improve the anticancer effect. The mechanisms of TKI resistance are summarized, and current strategies to overcome TKI resistance as well as the application of TKI in reversing chemotherapy resistance are discussed. Finally, we provide a perspective on the future research of EGFR-TKI-based cancer therapy.

Design of erythrocyte-derived carriers for bioimaging applications

Erythrocytes are physiological entities that have been exploited in both preclinical and clinical trials for the delivery of exogenous agents. Over the years, diverse erythrocyte-derived carriers (ECs) have been developed with related patents granted for industrial and commercial purposes. However, most ECs have only been exploited for drug delivery. Serious discussions regarding their applications in imaging are scarce. This article reviews the role of ECs in enhancing imaging efficiency and subsequently delineates strategies for engineering and optimising their preclinical and clinical performance. With a snapshot of the latest developments and use of ECs in imaging, directions to streamline the clinical translation of related technologies can be attained for future research.

Biomimetic Antidote Nanoparticles: a Novel Strategy for Chronic Heavy Metal Poisoning

Chronic lead poisoning has become a major factor in global public health. Chelation therapy is usually used to manage lead poisoning. Dimercaptosuccinic acid (DMSA) is a widely used heavy metal chelation agent. However, DMSA has the characteristics of poor water solubility, low oral bioavailability, and short half-life, which limit its clinical application. Herein, a long-cycle slow-release nanodrug delivery system was constructed. We successfully coated the red blood cell membrane (RBCM) onto the surface of dimercaptosuccinic acid polylactic acid glycolic acid copolymer (PLGA) nanoparticles (RBCM-DMSA-NPs), which have a long cycle and detoxification capabilities. The NPs were characterized and observed by particle size meters and transmission electron microscopy. The results showed that the particle size of RBCM-DMSA-NPs was approximately 146.66 ± 2.41 nm, and the zeta potential was - 15.34 ± 1.60 mV. The homogeneous spherical shape and clear core-shell structure of the bionic nanoparticles were observed by transmission electron microscopy. In the animal tests, the area under the administration time curve of RBCM-DMSA-NPs was 156.52 ± 2.63 (mg/L·h), which was 5.21-fold and 2.36-fold that of free DMSA and DMSA-NPs, respectively. Furthermore, the median survival of the RBCM-DMSA-NP treatment group (47 days) was 3.61-fold, 1.32-fold, and 1.16-fold for the lead poisoning group, free DMSA, and DMSA-NP groups, respectively. The RBCM-DMSA-NP treatment significantly extended the cycle time of the drug in the body and improved the survival rate of mice with chronic lead poisoning. Histological analyses showed that RBCM-DMSA-NPs did not cause significant systemic toxicity. These results indicated that RBCM-DMSA-NPs could be a potential candidate for long-term chronic lead exposure treatment.

Recent advances in erythrocyte membrane-camouflaged nanoparticles for the delivery of anti-cancer therapeutics

INTRODUCTION

Red blood cell (or erythrocyte) membrane-camouflaged nanoparticles (RBC-NPs) not only have a superior circulation life and do not induce accelerated blood clearance, but also possess special functions, which offers great potential in cancer therapy.

AREAS COVERED

This review focuses on the recent advances of RBC-NPs for delivering various agents to treat cancers in light of their vital role in improving drug delivery. Meanwhile, the construction and in vivo behavior of RBC-NPs are discussed to provide an in-depth understanding of the basis of RBC-NPs for improved cancer drug delivery.

EXPERT OPINION

Although RBC-NPs are quite prospective in delivering anti-cancer therapeutics, they are still in their infancy stage and many challenges need to be overcome for successful translation into the clinic. The preparation and modification of RBC membranes, the optimization of coating methods, the scale-up production and the quality control of RBC-NPs, and the drug loading and release should be carefully considered in the clinical translation of RBC-NPs for cancer therapy.

Nanoparticles as Physically- and Biochemically-Tuned Drug Formulations for Cancers Therapy

Simple Summary

Conventional antitumor drugs have limitations, including poor water solubility and lack of targeting capability, with consequent non-specific distribution, systemic toxicity, and low therapeutic index. Nanotechnology promises to overcome these drawbacks by exploiting the physical properties of diverse nanocarriers that can be linked to moieties with binding selectivity for cancer cells. The use of nanoparticles as therapeutic formulations allows a targeted delivery and a slow, controlled release of the drug(s), making them tunable modules for applications in precision medicine. In addition, nanoparticles are also being developed as cancer vaccines, offering an opportunity to increase both cellular and humoral immunity, thus providing a new weapon to beat cancer.

Abstract

Malignant tumors originate from a combination of genetic alterations, which induce activation of oncogenes and inactivation of oncosuppressor genes, ultimately resulting in uncontrolled growth and neoplastic transformation. Chemotherapy prevents the abnormal proliferation of cancer cells, but it also affects the entire cellular network in the human body with heavy side effects. For this reason, the ultimate aim of cancer therapy remains to selectively kill cancer cells while sparing their normal counterparts. Nanoparticle formulations have the potential to achieve this aim by providing optimized drug delivery to a pathological site with minimal accumulation in healthy tissues. In this review, we will first describe the characteristics of recently developed nanoparticles and how their physical properties and targeting functionalization are exploited depending on their therapeutic payload, route of delivery, and tumor type. Second, we will analyze how nanoparticles can overcome multidrug resistance based on their ability to combine different therapies and targeting moieties within a single formulation. Finally, we will discuss how the implementation of these strategies has led to the generation of nanoparticle-based cancer vaccines as cutting-edge instruments for cancer immunotherapy.

Novel Tumor-Targeting Nanoparticles for Cancer Treatment—A Review

Being one of the leading causes of death and disability worldwide, cancer represents an ongoing interdisciplinary challenge for the scientific community. As currently used treatments may face limitations in terms of both efficiency and adverse effects, continuous research has been directed towards overcoming existing challenges and finding safer specific alternatives. In particular, increasing interest has been gathered around integrating nanotechnology in cancer management and subsequentially developing various tumor-targeting nanoparticles for cancer applications. In this respect, the present paper briefly describes the most used cancer treatments in clinical practice to set a reference framework for recent research findings, further focusing on the novel developments in the field. More specifically, this review elaborates on the top recent studies concerning various nanomaterials (i.e., carbon-based, metal-based, liposomes, cubosomes, lipid-based, polymer-based, micelles, virus-based, exosomes, and cell membrane-coated nanomaterials) that show promising potential in different cancer applications.

Advancements in cell membrane camouflaged nanoparticles: A bioinspired platform for cancer therapy

The idea of employing natural cell membranes as a coating medium for nanoparticles (NPs) endows man-made vectors with natural capabilities and benefits. In addition to retaining the physicochemical characteristics of the NPs, the biomimetic NPs also have the functionality of source cell membranes. It has emerged as a promising approach to enhancing the properties of NPs for drug delivery, immune evasion, imaging, cancer-targeting, and phototherapy sensitivity. Several studies have been reported with a multitude of approaches to reengineering the surface of NPs using biological membranes. Owing to their low immunogenicity and intriguing biomimetic properties, cell-membrane-based biohybrid delivery systems have recently gained a lot of interest as therapeutic delivery systems. This review summarises different kinds of biomimetic NPs reported so far, their fabrication aspects, and their application in the biomedical field. Finally, it briefs on the latest advances available in this biohybrid concept.

Enhanced tumor accumulation and therapeutic efficacy of liposomal drugs through over-threshold dosing

Background

Most intravenously administered drug-loaded nanoparticles are taken up by liver Kupffer cells, and only a small portion can accumulate at the tumor, resulting in an unsatisfactory therapeutic efficacy and side effects for chemotherapeutic agents. Tumor-targeted drug delivery proves to be the best way to solve this problem; however, the complex synthesis, or surface modification process, together with the astonishing high cost make its clinical translation nearly impossible.

Methods

Referring to Ouyang’s work and over-threshold dosing theory in general, blank PEGylated liposomes (PEG-Lipo) were prepared and used as tumor delivery enhancers to determine whether they could significantly enhance the tumor accumulation and in vivo antitumor efficacy of co-injected liposomal ACGs (PEG-ACGs-Lipo), a naturally resourced chemotherapeutic. Here, the phospholipid dose was used as an indicator of the number of liposomes particles with similar particle sizes, and the liposomes was labelled with DiR, a near-red fluorescent probe, to trace their in vivo biodistribution. Two mouse models, 4T1-bearing and U87-bearing, were employed for in vivo examination.

Results

PEG-Lipo and PEG-ACGs-Lipo had similar diameters. At a low-threshold dose (12 mg/kg equivalent phospholipids), PEG-Lipo was mainly distributed in the liver rather than in the tumor, with the relative tumor targeting index (RTTI) being ~ 0.38 at 72 h after administration. When over-threshold was administered (50 mg/kg or 80 mg/kg of equivalent phospholipids), a much higher and quicker drug accumulation in tumors and a much lower drug accumulation in the liver were observed, with the RTTI increasing to ~ 0.9. The in vivo antitumor study in 4T1 tumor-bearing mice showed that, compared to PEG-ACGs-Lipo alone (2.25 mg/kg phospholipids), the co-injection of a large dose of blank PEG-Lipo (50 mg/kg of phospholipids) significantly reduced the tumor volume of the mice by 22.6% (P < 0.05) and enhanced the RTTI from 0.41 to 1.34. The intravenous injection of a low drug loading content (LDLC) of liposomal ACGs (the same dose of ACGs at 50 mg/kg of equivalent phospholipids) achieved a similar tumor inhibition rate (TIR) to that of co-injection. In the U87 MG tumor-bearing mouse model, co-injection of the enhancer also significantly promoted the TIR (83.32% vs. 66.80%, P < 0.05) and survival time of PEG-ACGs-Lipo.

Conclusion

An over-threshold dosing strategy proved to be a simple and feasible way to enhance the tumor delivery and antitumor efficacy of nanomedicines and was benefited to benefit their clinical result, especially for liposomal drugs.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01349-1.