Alliance with EPR Effect: Combined Strategies to Improve the EPR Effect in the Tumor Microenvironment

Piezocatalytic Medicine: An Emerging Frontier using Piezoelectric Materials for Biomedical Applications

Emerging piezocatalysts have demonstrated their remarkable application potential in diverse medical fields. In addition to their ultrahigh catalytic activities, their inherent and unique charge-carrier-releasing properties can be used to initiate various redox catalytic reactions, displaying bright prospects for future medical applications. Triggered by mechanical energy, piezocatalytic materials can release electrons/holes, catalyze redox reactions of substrates, or intervene in biological processes to promote the production of effector molecules for medical purposes, such as decontamination, sterilization, and therapy. Such a medical application of piezocatalysis is termed as piezocatalytic medicine (PCM) herein. To pioneer novel medical technologies, especially therapeutic modalities, this review provides an overview of the state-of-the-art research progress in piezocatalytic medicine. First, the principle of piezocatalysis and the preparation methodologies of piezoelectric materials are introduced. Then, a comprehensive summary of the medical applications of piezocatalytic materials in tumor treatment, antisepsis, organic degradation, tissue repair and regeneration, and biosensing is provided. Finally, the main challenges and future perspectives in piezocatalytic medicine are discussed and proposed, expecting to fuel the development of this emerging scientific discipline.

Supramolecular nanofibers co-loaded with dabrafenib and doxorubicin for targeted and synergistic therapy of differentiated thyroid carcinoma

Rationale: Although surgery, radioiodine therapy, and thyroid hormone therapy are the primary clinical treatments for differentiated thyroid carcinoma (DTC), effective therapy for locally advanced or progressive DTC remains challenging. BRAF V600E, the most common BRAF mutation subtype, is highly related to DTC. Previous studies prove that combination of kinase inhibitors and chemotherapeutic drugs may be a potential approach for DTC treatment. In this study, a supramolecular peptide nanofiber (SPNs) co-loaded with dabrafenib (Da) and doxorubicin (Dox) was constructed for targeted and synergistic therapy with BRAF V600E⁺ DTC. Methods: A self-assembling peptide nanofiber (Biotin-G^DF^DF^DYGRGD, termed SPNs) bearing biotin at the N-terminus and a cancer-targeting ligand RGD at the C-terminus was used as a carrier for co-loading Da and Dox. D-phenylalanine and D-tyrosine (^DF^DF^DY) are used to improve the stability of peptides in vivo. Under multiple non-covalent interactions, SPNs/Da/Dox assembled into longer and denser nanofibers. RGD ligand endows self-assembled nanofibers with targeting cancer cells and co-delivery, thereby improving cellular uptake of payloads. Results: Both Da and Dox indicated decreased IC50 values upon encapsulation in SPNs. Co-delivery of Da and Dox by SPNs exhibited the strongest therapeutic effect in vitro and in vivo by inhibiting ERK phosphorylation in BRAF V600E mutant thyroid cancer cells. Moreover, SPNs enable efficient drug delivery and lower Dox dosage, thereby significantly reducing its side effects. Conclusion: This study proposes a promising paradigm for the synergistic treatment of DTC with Da and Dox using supramolecular self-assembled peptides as carriers.

Establishment of ultrasound-responsive SonoBacteriaBot for targeted drug delivery and controlled release

Bacteria-driven biohybrid microbots have shown great potential in caⁿcer treatment. However, how precisely controlling drug release at the tumor site is still an issue. To overcome the limitation of this system, we proposed the ultrasound-responsive SonoBacteriaBot (DOX-PFP-PLGA@EcM). Doxorubicin (DOX) and perfluoro-n-pentane (PFP) were encapsulated in polylactic acid-glycolic acid (PLGA) to form ultrasound-responsive DOX-PFP-PLGA nanodroplets. Then, DOX-PFP-PLGA@EcM is created by DOX-PFP-PLGA amide-bonded to the surface of E. coli MG1655 (EcM). The DOX-PFP-PLGA@EcM was proved to have the characteristics of high tumor-targeting efficiency, controlled drug release capability, and ultrasound imaging. Based on the acoustic phase change function of nanodroplets, DOX-PFP-PLGA@EcM enhance the signal of US imaging after ultrasound irradiation. Meanwhile, the DOX loaded into DOX-PFP-PLGA@EcM can be released. After being intravenously injected, DOX-PFP-PLGA@EcM can efficiently accumulate in tumors without causing harm to critical organs. In conclusion, the SonoBacteriaBot has significant benefits in real-time monitoring and controlled drug release, which has significant potential applications for therapeutic drug delivery in clinical settings.

Nanoparticles Containing Oxaliplatin and the Treatment of Colorectal Cancer

BACKGROUND

Colorectal cancer (CRC) is a highly widespread malignancy and ranks as the second most common cause of cancer-related mortality.

OBJECTIVE

Cancer patients, including those with CRC, who undergo chemotherapy, are often treated with platinum- based anticancer drugs such as oxaliplatin (OXA). Nevertheless, the administration of OXA is associated with a range of gastrointestinal problems, neuropathy, and respiratory tract infections. Hence, it is necessary to devise a potential strategy that can effectively tackle these aforementioned challenges. The use of nanocarriers has shown great potential in cancer treatment due to their ability to minimize side effects, target drugs directly to cancer cells, and improve drug efficacy. Furthermore, numerous studies have been published regarding the therapeutic efficacy of nanoparticles in the management of colorectal cancer.

METHODS

In this review, we present the most relevant nanostructures used for OXA encapsulation in recent years, such as solid lipid nanoparticles, liposomes, polysaccharides, proteins, silica nanoparticles, metal nanoparticles, and synthetic polymer-carriers. Additionally, the paper provides a summary of the disadvantages and limits associated with nanoparticles.

RESULTS

The use of different carriers for the delivery of oxaliplatin increased the efficiency and reduced the side effects of the drug. It has been observed that the majority of research investigations have focused on liposomes and polysaccharides.

CONCLUSION

This potentially auspicious method has the potential to enhance results and enhance the quality of life for cancer patients undergoing chemotherapy. However, additional investigation is required to ascertain the most suitable medium for the transportation of oxaliplatin and to assess its efficacy through clinical trials.

Highlights of New Strategies to Increase the Efficacy of Transition Metal Complexes for Cancer Treatments

Although important progress has been made, cancer still remains a complex disease to treat. Serious side effects, the insurgence of resistance and poor selectivity are some of the problems associated with the classical metal-based anti-cancer therapies currently in clinical use. New treatment approaches are still needed to increase cancer patient survival without cancer recurrence. Herein, we reviewed two promising-at least in our opinion-new strategies to increase the efficacy of transition metal-based complexes. First, we considered the possibility of assembling two biologically active fragments containing different metal centres into the same molecule, thus obtaining a heterobimetallic complex. A critical comparison with the monometallic counterparts was done. The reviewed literature has been divided into two groups: the case of platinum; the case of gold. Secondly, the conjugation of metal-based complexes to a targeting moiety was discussed. Particularly, we highlighted some interesting examples of compounds targeting cancer cell organelles according to a third-order targeting approach, and complexes targeting the whole cancer cell, according to a second-order targeting strategy.

Shield-activated two-way imaging nanomaterials for enhanced cancer theranostics

Smart nanomaterials with stimuli-responsive imaging enhancement have been widely developed to meet the requirements of accurate cancer diagnosis. However, these imaging nanoenhancers tend to be always on during circulation, which significantly increases the background signal when assessing the imaging performance. To improve unfavorable signal-to-noise ratios, an effective way is to shield the noise signal of these nanoprobes in non-targeted areas. Fortunately, there is a natural mutual shielding effect between some imaging nanomaterials, which provides the possibility of designing engineered nanomaterials with imaging quenching between two different components at the beginning. Once in the tumor microenvironment, the two components will present activated dual-mode imaging ability because of their separation, designated as two-way imaging tuning. This review highlights the design and mechanism of a series of engineered nanomaterials with two-way imaging tuning and their latest applications in the fields of cancer magnetic resonance imaging, fluorescence imaging, and their combination. The challenges and future directions for the improvement of these engineered nanomaterials towards clinical transformation are also discussed. This review aims to introduce the special constraint relationships of imaging components and provide scientists with simpler and more efficient nanoplatform construction ideas, promoting the development of engineered nanomaterials with two-way imaging tuning in cancer theranostics.

Improve the cytotoxic effects of megavoltage radiation treatment by Fe3O4@Cus–PEG nanoparticles as a novel radiosensitizer in colorectal cancer cells

Background

To enhance the performance of radiotherapy, emerging nanoparticles that can professionally enhance X-ray irradiation to destruct cancer cells are extremely necessary. Here, we examined the potential of PEG-coated magnetite copper sulfide hetero-nanoparticles (Fe3O4@Cus–PEG) as a radiosensitizer agent.

Methods

Fe3O4@Cus–PEG nanoparticles were synthesized and characterized. The toxicity of nanoparticles on HT-29 colorectal cancer cells was assessed by the MTT assay. The radio-sensitizing effects of Fe3O4@Cus–PEG nanoparticles on HT-29 cancer cells were investigated by the MTT and colony formation assays. Moreover, the underlying mechanisms for Fe3O4@Cus–PEG nanoparticles to improve the radiation sensitivity of cells were evaluated.

Results

The results demonstrated that nanoparticles enhanced the effects of X-ray irradiation in a dose-dependent manner. The effects of combined treatments (nanoparticles and X-ray radiation) were strongly synergistic. The sensitizing enhancement ratio (SER) of nanoparticles was 2.02. Our in vitro assays demonstrated that the nitric oxide production, the intracellular hydrogen peroxide concentration, and the expression level of Bax and Caspase-3 genes significantly increased in the cells treated with the combination of nanoparticles and radiation. Whereas, the Glutathione peroxidase enzyme activity and the expression level of the Bcl-2 gene in the combined treatment significantly decreased compared to the radiation alone.

Conclusions

Our study suggests that Fe3O4@Cus–PEG nanoparticles are the promising nano radio-sensitizing agents for the treatment of cancer cells to enhance the efficacy of radiation therapy through increasing the reactive oxygen species generation, nitric oxide production, and inducing apoptosis.

Graphical Abstract

Cell-Derived Vesicles for Nanoparticles' Coating: Biomimetic Approaches for Enhanced Blood Circulation and Cancer Therapy

Cancer nanomedicines are designed to encapsulate different therapeutic agents, prevent their premature release, and deliver them specifically to cancer cells, due to their ability to preferentially accumulate in tumor tissue. However, after intravenous administration, nanoparticles immediately interact with biological components that facilitate their recognition by the immune system, being rapidly removed from circulation. Reports show that less than 1% of the administered nanoparticles effectively reach the tumor site. This suboptimal pharmacokinetic profile is pointed out as one of the main factors for the nanoparticles' suboptimal therapeutic effectiveness and poor translation to the clinic. Therefore, an extended blood circulation time may be crucial to increase the nanoparticles' chances of being accumulated in the tumor and promote a site-specific delivery of therapeutic agents. For that purpose, the understanding of the forces that govern the nanoparticles' interaction with biological components and the impact of the physicochemical properties on the in vivo fate will allow the development of novel and more effective nanomedicines. Therefore, in this review, the nano-bio interactions are summarized. Moreover, the application of cell-derived vesicles for extending the blood circulation time and tumor accumulation is reviewed, focusing on the advantages and shortcomings of each cell source.

The tumor EPR effect for cancer drug delivery: Current status, limitations, and alternatives

Over the past three decades, the enhanced permeability and retention (EPR) effect has been considered the basis of tumor-targeted drug delivery. Various cancer nanomedicines, including macromolecular drugs, have been designed to utilize this mechanism for preferential extravasation and accumulation in solid tumors. However, such nanomedicines have not yet achieved convincing therapeutic benefits in clinics. Increasing evidence suggests that the EPR effect is over-represented in human tumors, especially in metastatic tumors. This review covers the evolution of the concept, the heterogeneity and limitation of the EPR effect in clinical realities, and prospects for alternative strategies independent of the EPR effect.

Co-delivery of paclitaxel (PTX) and docosahexaenoic acid (DHA) by targeting lipid nanoemulsions for cancer therapy

Breast cancer is one of the most common types of cancer in female patients with high morbidity and mortality. Multi-drug chemotherapy has significant advantages in the treatment of malignant tumors, especially in reducing drug toxicity, increasing drug sensitivity and reducing drug resistance. The objective of this research is to fabricate lipid nanoemulsions (LNs) for the co-delivery of PTX and docosahexaenoic acid (DHA) with folic acid (FA) decorating (PTX/DHA-FA-LNs), and investigate the anti-tumor activity of the PTX/DHA-FA-LNs against breast cancer both in vitro and in vivo. PTX/DHA-FA-LNs showed a steady release of PTX and DHA from the drug delivery system (DDS) without any burst effect. Furthermore, the PTX/DHA-FA-LNs exhibited a dose-dependent cytotoxicity and a higher rate of apoptosis as compared with the other groups in MCF-7 cells. The cellular uptake study revealed that this LNs were more readily uptaken by MCF-7 cells and M2 macrophages in vitro. Additionally, the targeted effect of PTX/DHA-FA-LNs was aided by FA receptor-mediated endocytosis, and its cytotoxicity was proportional to the cellular uptake efficiency. The anti-tumor efficiency results showed that PTX/DHA-FA-LNs significant inhibited tumor volume growth, prolonged survival time, and reduced toxicity when compared with the other groups. These results indicated that DHA increases the sensitivity of tumor cells and tumor-associated macrophages (ATM2) to PTX, and synergistic effects of folate modification in breast cancer treatment, thus PTX/DHA-FA-LNs may be a promising nanocarrier for breast cancer treatment.

A Nanomedicine Structure-Activity Framework for Research, Development, and Regulation of Future Cancer Therapies

Despite their clinical success in drug delivery applications, the potential of theranostic nanomedicines is hampered by mechanistic uncertainty and a lack of science-informed regulatory guidance. Both the therapeutic efficacy and the toxicity of nanoformulations are tightly controlled by the complex interplay of the nanoparticle's physicochemical properties and the individual patient/tumor biology; however, it can be difficult to correlate such information with observed outcomes. Additionally, as nanomedicine research attempts to gradually move away from large-scale animal testing, the need for computer-assisted solutions for evaluation will increase. Such models will depend on a clear understanding of structure-activity relationships. This review provides a comprehensive overview of the field of cancer nanomedicine and provides a knowledge framework and foundational interaction maps that can facilitate future research, assessments, and regulation. By forming three complementary maps profiling nanobio interactions and pathways at different levels of biological complexity, a clear picture of a nanoparticle's journey through the body and the therapeutic and adverse consequences of each potential interaction are presented.

Ruthenium-based antitumor drugs and delivery systems from monotherapy to combination therapy

Ruthenium complex is an important compound group for antitumor drug research and development. NAMI-A, KP1019, TLD1433 and other ruthenium complexes have entered clinical research. In recent years, the research on ruthenium antitumor drugs has not been limited to single chemotherapy drugs; other applications of ruthenium complexes have emerged such as in combination therapy. During the development of ruthenium complexes, drug delivery forms of ruthenium antitumor drugs have also evolved from single-molecule drugs to nanodrug delivery systems. The review summarizes the following aspects: (1) ruthenium complexes from monotherapy to combination therapy, including the development of single-molecule compounds, carrier nanomedicine, and self-assembly of carrier-free nanomedicine; (2) ruthenium complexes in the process of ADME in terms of absorption, distribution, metabolism and excretion; (3) the applications of ruthenium complexes in combination therapy, including photodynamic therapy (PDT), photothermal therapy (PTT), photoactivated chemotherapy (PACT), immunotherapy, and their combined application; (4) the future prospects of ruthenium-based antitumor drugs.

Peptide-Drug Conjugates: A New Hope for Cancer Management

Cancer remains the leading cause of death worldwide despite advances in treatment options for patients. As such, safe and effective therapeutics are required. Short peptides provide advantages to be used in cancer management due to their unique properties, amazing versatility, and progress in biotechnology to overcome peptide limitations. Several appealing peptide-based therapeutic strategies have been developed. Here, we provide an overview of peptide conjugates, the better equivalents of antibody-drug conjugates, as the next generation of drugs for required precise targeting, enhanced cellular permeability, improved drug selectivity, and reduced toxicity for the efficient treatment of cancers. We discuss the basic components of drug conjugates and their release action, including the release of cytotoxins from the linker. We also present peptide-drug conjugates under different stages of clinical development as well as regulatory and other challenges.

Gold-Nanoparticle Hybrid Nanostructures for Multimodal Cancer Therapy

With the urgent need for bio-nanomaterials to improve the currently available cancer treatments, gold nanoparticle (GNP) hybrid nanostructures are rapidly rising as promising multimodal candidates for cancer therapy. Gold nanoparticles (GNPs) have been hybridized with several nanocarriers, including liposomes and polymers, to achieve chemotherapy, photothermal therapy, radiotherapy, and imaging using a single composite. The GNP nanohybrids used for targeted chemotherapy can be designed to respond to external stimuli such as heat or internal stimuli such as intratumoral pH. Despite their promise for multimodal cancer therapy, there are currently no reviews summarizing the current status of GNP nanohybrid use for cancer theragnostics. Therefore, this review fulfills this gap in the literature by providing a critical analysis of the data available on the use of GNP nanohybrids for cancer treatment with a specific focus on synergistic approaches (i.e., triggered drug release, photothermal therapy, and radiotherapy). It also highlights some of the challenges that hinder the clinical translation of GNP hybrid nanostructures from bench to bedside. Future studies that could expedite the clinical progress of GNPs, as well as the future possibility of improving GNP nanohybrids for cancer theragnostics, are also summarized.

Targeting cancer stem cells with polymer nanoparticles for gastrointestinal cancer treatment

Nanomaterials are developing rapidly in the medical field, bringing new hope for treating various refractory diseases. Among them, polymer nanomaterials, with their excellent properties, have been used to treat various diseases, such as malignant tumors, diabetes, and nervous system diseases. Gastrointestinal cancer is among the cancers with the highest morbidity and mortality worldwide. Cancer stem cells are believed to play an important role in the occurrence and development of tumors. This article summarizes the characteristics of gastrointestinal cancer stem cells and reviews the latest research progress in treating gastrointestinal malignant tumors using polymer nanoparticles to target cancer stem cells. In addition, the review article highlights the potential of polymer nanoparticles in targeting gastrointestinal cancer stem cells.

Transcytosis-enabled active extravasation of tumor nanomedicine

Extravasation is the first step for nanomedicines in circulation to reach targeted solid tumors. Traditional nanomedicines have been designed to extravasate into tumor interstitium through the interendothelial gaps previously assumed rich in tumor blood vessels, i.e., the enhanced permeability and retention (EPR) effect. While the EPR effect has been validated in animal xenograft tumor models, accumulating evidence implies that the EPR effect is very limited and highly heterogeneous in human tumors, leading to highly unpredictable and inefficient extravasation and thus limited therapeutic efficacy of nanomedicines, including those approved in clinics. Enabling EPR-independent extravasation is the key to develop new generation of nanomedicine with enhanced efficacy. Transcytosis of tumor endothelial cells can confer nanomedicines to actively extravasate into solid tumors without relying on the EPR effect. Here, we review and prospectthe development of transcytosis-inducing nanomedicines, in hope of providing instructive insights for design of nanomedicines that can undergo selective transcellular transport across tumor endothelial cells, and thus inspiring the development of next-generation nanomedicines for clinical translation.

Exploring the relationship between autophagy and Gefitinib resistance in NSCLC by silencing PDLIM5 using ultrasound-targeted microbubble destruction technology

BACKGROUND

Ultrasound-targeted microbubble destruction (UTMD) technology is a new drug and gene delivery strategy. This study investigates novel ultrasound (US) sensitive siRNA-loaded nanobubbles (siRNA-NBs) to explore the relationship between PDLIM5 mediated autophagy and drug resistance development using epidermal growth factor tyrosine kinase inhibitors (EGFR-TKIs) in the treatment of non-small cell lung cancer (NSCLC).

METHODS

US sensitive siRNA-NBs were designed to inhibit the expression of PDLIM5 in gefitinib-resistant human NSCLC PC9GR cells in vitro. The expression of autophagy-related proteins (P62 and LC3-II/I) and autophagosomes in PC9GR cells after PDLIM5 gene silencing were explored.

RESULTS

US-sensitive PDLIM5-targeted siRNA-NBs were effectively delivered into PC9GR cells, inhibiting PDLIM5 expression, increasing LC3-II/I and p62 expressions and increasing autophagosomes in PC9GR cells in vitro.

CONCLUSIONS

Using UTMD, US-sensitive siRNA-NBs have the potential as an ideal delivery vector to mediate highly effective RNA interference for NSCLC cells. Furthermore, PDLIM5 plays a role in the autophagy-mediated resistance in gefitinib-resistant PC9GR cells.

Prediction the clinical EPR effect of nanoparticles in patient-derived xenograft models

Many preclinically tested nanoparticles in existing animal models fail to be directly translated into clinical applications because of their poor resemblance to human cancer. Herein, the enhanced permeation and retention (EPR) effect of glycol chitosan nanoparticles (CNPs) in different tumor microenvironments (TMEs) was compared using different pancreatic tumor models, including pancreatic cancer cell line (BxPC3), patient-derived cancer cell (PDC), and patient-derived xenograft (PDX) models. CNPs were intravenously injected into different tumor models, and their accumulation efficiency was evaluated using non-invasive near-infrared fluorescence (NIRF) imaging. In particular, differences in angiogenic vessel density, collagen matrix, and hyaluronic acid content in tumor tissues of the BxPC3, PDC, and PDX models greatly affected the tumor-targeting efficiency of CNPs. In addition, different PDX models were established using different tumor tissues of patients to predict the clinical EPR effect of CNPs in inter-patient TMEs, wherein the gene expression levels of PECAM1, COL4A1, and HAS1 in human tumor tissues were observed to be closely related to the EPR effect of CNPs in PDX models. The results suggested that the PDX models could mimic inter-patient TMEs with different blood vessel structures and extracellular matrix (ECM) content that critically affect the tumor-targeting ability of CNPs in different pancreatic PDX models. This study provides a better understanding of the heterogeneity and complexity of inter-patient TMEs that can predict the response of various nanoparticles in individual tumors for personalized cancer therapy.

Nanodelivery of cGAS-STING activators for tumor immunotherapy

Activation of the cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-stimulator of interferon genes (STING) pathway has great potential to promote antitumor immunity. Development of activators for the cGAS-STING pathway (cGAS-STING activators) has profoundly revolutionized tumor immunotherapy. However, successful clinical application of cGAS-STING activators is contingent on having appropriate systems to achieve safe, effective, and specific delivery. There is an increasing emphasis on the design and application of nano drug delivery systems (NDDS) that can facilitate the delivery potential of cGAS-STING activators. In this review, we discuss barriers for translational development of cGAS-STING activators (DNA damaging drugs and STING agonists) and recent advances of NDDS for these agents in tumor immunotherapy.

Recent advances in biological membrane-based nanomaterials for cancer therapy

Nanomaterials have shown significant advantages in cancer theranostics, owing to their enhanced permeability and retention effect in tumors and multi-function integration capability. Biological membranes, which are collected from various cells and their secreted membrane structures, can further be applied to establish membrane-based nanomaterials with perfect biocompatibility, tumor-targeting capacity, immune-stimulatory activity and adjustable versatility for cancer therapy. In this review, according to their source, membranes are divided into four groups: (1) cell membranes; (2) secretory membranes; (3) engineered membranes; and (4) hybrid membranes. First, cell membranes can be extracted from natural cells of the body, tumor tissue cells, and bacteria. Furthermore, secretory membranes mainly refer to exosome, apoptotic body and bacterial outer membrane vesicle, and membranes with specific protein/peptide expression or therapeutic inclusions are obtained from engineered cells. Finally, a hybrid membrane will be constituted by two or more of the abovementioned membranes. These membranes can form drug-carrying nanoparticles themselves or coat multi-functional nanoparticles, further realizing efficient cancer therapy. We summarize the application of various biological membrane-based nanomaterials in cancer therapy and point out their advantages as well as the places that need to be further improved, providing systematic knowledge of this field and a strategy for further optimization.

Nanomaterials for Natural Killer Cell-Based Immunoimaging and Immunotherapies in Cancer

Natural killer (NK) cells are an important component of the tumor immunosurveillance; activated NK cells can recognize and directly lyse tumor cells eliciting a potent antitumor immune response. Due to their intrinsic ability to unleash cytotoxicity against tumor cells, NK cell-based adoptive cell therapies have gained rapid clinical significance, and many clinical trials are ongoing. However, priming and activating NK cells, infiltration of activated NK cells in the immunosuppressive tumor microenvironment, and tracking the infiltrated NK cells in the tumors remain a critical challenge. To address these challenges, NK cells have been successfully interfaced with nanomaterials where the morphology, composition, and surface characteristics of nanoparticles (NPs) were leveraged to enable longitudinal tracking of NK cells in tumors or deliver therapeutics to prime NK cells. Distinct from other published reviews, in this tutorial review, we summarize the recent findings in the past decade where NPs were used to label NK cells for immunoimaging or deliver treatment to activate NK cells and induce long-term immunity against tumors. We discuss the NP properties that are key to surmounting the current challenges in NK cells and the different strategies employed to advance NK cells-based diagnostics and therapeutics. We conclude the review with an outlook on future directions in NP-NK cell hybrid interfaces, and overall clinical impact and patient response to such interfaces that need to be addressed to enable their clinical translation.

Single-molecule photosensitizers for NIR-II fluorescence and photoacoustic imaging guided precise anticancer phototherapy

It is ideal yet challenging to achieve precise tumor targeting and high-quality imaging guided combined photodynamic and photothermal therapy (PDT and PTT). In this study, we synthesized a series of D-π-A-type single-molecule photosensitizers (CyE-TT, CyQN-TT, and CyQN-BTT) based on quaternized 1,1,2-trimethyl-1H-benz[e]indoles as acceptors by introducing π-bridges to elongate their emission wavelength and triphenylamine as a donor to construct a twisted molecular conformation. We found that the 1O2 generation ability and the photothermal conversion efficiency (PCE) are directly correlated with the π-bridge between donors and acceptors in these molecules. When a 2,1,3-benzothiadiazole group as a π-bridge was introduced into CyQN-BTT, the singlet oxygen yield enhanced to 27.1%, PCE to 37.8%, and the emission wavelength was red-shifted to near-infrared II (NIR-II). Importantly, double-cationic CyQN-BTT displays structure-inherent cancer cell targeting ability instead of targeting normal cells. Consequently, relying on NIR-II fluorescence imaging (NIR-II FLI) and photoacoustic imaging (PAI) guided PDT and PTT, CyQN-BTT can accurately locate solid tumors in mice and effectively eliminate them with good biocompatibility and biosafety to normal tissues. This study provides insights into the design and development of a tumor-specific targeting multifunctional photosensitizer for precise cancer phototherapy.

Recent advances in redox-responsive nanoparticles for combined cancer therapy

The combination of multiple therapeutic modalities has attracted increasing attention as it can achieve better therapeutic effects through different treatment mechanisms. However, traditional small molecule agents are non-specific to the tumor tissue, which leads to off-target toxic effects for healthy tissues. To solve this problem, a number of stimuli-responsive nanoscale drug-delivery systems have been developed. Among these stimuli, a high concentration of reactive oxygen species (ROS) and glutathione (GSH) are characteristic of the tumor microenvironment (TME), which can distinguish it from normal tissue. In this review, we summarize the redox-responsive nanoparticles (NPs) reported in the past three years classified by different functional groups, including GSH-responsive disulfide, ditelluride, and multivalent metal ions, ROS-responsive thioketal, arylboronic ester, aminoacrylate, and bilirubin as well as GSH/ROS dual-responsive diselenide and dicarbonyl thioethers. The prospects and challenges of redox-responsive NPs are also discussed.

Analysis of Stable Chelate-free Gadolinium Loaded Titanium Dioxide Nanoparticles for MRI-Guided Radionuclide Stimulated Cancer Treatment

Background

Recent studies demonstrate that titanium dioxide nanoparticles (TiO₂ NPs) are an effective source of reactive oxygen species (ROS) for photodynamic therapy and radionuclide stimulated dynamic therapy (RaST). Unfortunately tracking the in vivo distribution of TiO₂ NPs noninvasively remains elusive.

Objective

Given the use of gadolinium (Gd) chelates as effective contrast agents for magnetic resonance imaging (MRI), this study aims to (1) develop hybrid TiO₂-Gd NPs that exhibit high relaxivity for tracking the NPs without loss of ROS generating capacity; and (2) establish a simple colorimetric assay for quantifying Gd loading and stability.

Methods

A chelate-free, heat-induced method was used to load Gd onto TiO₂ NPs, which was coated with transferrin (Tf). A sensitive colorimetric assay and inductively coupled plasma mass spectrometry (ICP-MS) were used to determine Gd loading and stability of the TiO₂-Gd-Tf NPs. Measurement of the relaxivity was performed on a 1.4 T relaxometer and a 4.7 T small animal magnetic resonance scanner to estimate the effects of magnetic field strength. ROS was quantified by activated dichlorodihydrofluorescein diacetate fluorescence. Cell uptake of the NPs and RaST were monitored by fluorescence microscopy. Both 3 T and 4.7 T scanners were used to image the in vivo distribution of intravenously injected NPs in tumor-bearing mice.

Results

A simple colorimetric assay accurately determined both the loading and stability of the NPs compared with the expensive and complex ICP-MS method. Coating of the TiO₂-Gd NPs with Tf stabilized the nanoconstruct and minimized aggregation. The TiO₂-Gd-Tf maintained ROS-generating capability without inducing cell death at a wide range of concentrations but induced significant cell death under RaST conditions in the presence of F-18 radiolabeled 2-fluorodeoxyglucose. The longitudinal (r1 = 10.43 mM^-1s^-1) and transverse (r2 = 13.43 mM^-1s^-1) relaxivity of TiO₂-Gd-Tf NPs were about twice and thrice, respectively, those of clinically used Gd contrast agent (Gd-DTPA; r1 = 3.77 mM^-1s^-1 and r2 = 5.51 mM^-1s^-1) at 1.4 T. While the r1 (8.13 mM^-1s^-1) reduced to about twice that of Gd-DTPA (4.89 mM^-1s^-1) at 4.7 T, the corresponding r2 (87.15 mM^-1s^-1) increased by a factor 22.6 compared to Gd-DTPA (r2 = 3.85). MRI of tumor-bearing mice injected with TiO₂-Gd-Tf NPs tracked the NPs distribution and accumulation in tumors.

Conclusion

This work demonstrates that Arsenazo III colorimetric assay can substitute ICP-MS for determining the loading and stability of Gd-doped TiO₂ NPs. The new nanoconstruct enabled RaST effect in cells, exhibited high relaxivity, and enhanced MRI contrast in tumors in vivo, paving the way for in vivo MRI-guided RaST.

Inducible endothelial leakiness in nanotherapeutic applications

All intravenous delivered nanomedicine needs to escape from the blood vessel to exert their therapeutic efficacy at their designated site of action. Failure to do so increases the possibility of detrimental side effects and negates their therapeutic intent. Many powerful anticancer nanomedicine strategies rely solely on the tumor derived enhanced permeability and retention (EPR) effect for the only mode of escaping from the tumor vasculature. However, not all tumors have the EPR effect nor can the EPR effect be induced or controlled for its location and timeliness. In recent years, there have been exciting developments along the lines of inducing endothelial leakiness at the tumor to decrease the dependence of EPR. Physical disruption of the endothelial-endothelial cell junctions with coordinated biological intrinsic pathways have been proposed that includes various modalities like ultrasound, radiotherapy, heat and even nanoparticles, appear to show good progress towards the goal of inducing endothelial leakiness. This review explains the intricate and complex biological background behind the endothelial cells with linkages on how updated reported nanomedicine strategies managed to induce endothelial leakiness. This review will also end off with fresh insights on where the future of inducible endothelial leakiness holds.

Tumor microenvironment responsive nanocarriers for gene therapy

Stimuli responsive nanocarriers are important non-viral gene carriers for gene therapy. We discuss the stimulus conditions and then highlight various stimuli responsive nanocarriers in the tumor microenvironment for cancer gene therapy. We hope that this review will inspire readers to develop more effective stimuli responsive nanocarriers for delivering genes.

Boron Neutron Capture Therapy (BNCT) Mediated by Maleimide-Functionalized Closo-Dodecaborate Albumin Conjugates (MID:BSA) for Oral Cancer: Biodistribution Studies and In Vivo BNCT in the Hamster Cheek Pouch Oral Cancer Model

Background: BNCT (Boron Neutron Capture Therapy) is a tumor-selective particle radiotherapy that combines preferential boron accumulation in tumors and neutron irradiation. Although p-boronophenylalanine (BPA) has been clinically used, new boron compounds are needed for the advancement of BNCT. Based on previous studies in colon tumor-bearing mice, in this study, we evaluated MID:BSA (maleimide-functionalized closo-dodecaborate conjugated to bovine serum albumin) biodistribution and MID:BSA/BNCT therapeutic effect on tumors and associated radiotoxicity in the hamster cheek pouch oral cancer model. Methods: Biodistribution studies were performed at 30 mg B/kg and 15 mg B/kg (12 h and 19 h post-administration). MID:BSA/BNCT (15 mg B/kg, 19 h) was performed at three different absorbed doses to precancerous tissue. Results: MID:BSA 30 mg B/kg protocol induced high BSA toxicity. MID:BSA 15 mg B/kg injected at a slow rate was well-tolerated and reached therapeutically useful boron concentration values in the tumor and tumor/normal tissue ratios. The 19 h protocol exhibited significantly lower boron concentration values in blood. MID:BSA/BNCT exhibited a significant tumor response vs. the control group with no significant radiotoxicity. Conclusions: MID:BSA/BNCT would be therapeutically useful to treat oral cancer. BSA toxicity is a consideration when injecting a compound conjugated to BSA and depends on the animal model studied.

Peptide-Based Bioconjugates and Therapeutics for Targeted Anticancer Therapy

With rapidly growing knowledge in bioinformatics related to peptides and proteins, amino acid-based drug-design strategies have recently gained importance in pharmaceutics. In the past, peptide-based biomedicines were not widely used due to the associated severe physiological problems, such as low selectivity and rapid degradation in biological systems. However, various interesting peptide-based therapeutics combined with drug-delivery systems have recently emerged. Many of these candidates have been developed for anticancer therapy that requires precisely targeted effects and low toxicity. These research trends have become more diverse and complex owing to nanomedicine and antibody–drug conjugates (ADC), showing excellent therapeutic efficacy. Various newly developed peptide–drug conjugates (PDC), peptide-based nanoparticles, and prodrugs could represent a promising therapeutic strategy for patients. In this review, we provide valuable insights into rational drug design and development for future pharmaceutics.

Ultrasound-Responsive Peptide Nanogels to Balance Conflicting Requirements for Deep Tumor Penetration and Prolonged Blood Circulation

A series of biological barriers need to be overcome for therapeutic nanocarriers accumulating at the tumor site and uptaken by cancer cells. One strategy is to construct switchable nanocarriers to meet the conflicting requirements for various physiology environments. In this work, besides widely studied endogenous stimuli-responsiveness, an exogenous ultrasound responsiveness was additionally embedded into nanocarriers to balance the conflicting needs of prolonged blood circulation and deep tumor penetration. Polylysine and Pluronic F127 were first coassembled and then cross-linked by genipin to form stable nanogel structure. Subsequently, ICAM-1 antibody was grafted onto the nanogel (designated as GenPLPF_T) for active tumor targeting. Upon external sonication, the F127 was shed from GenPLPF_T to induce swelling of nanogel with reduced stability and accelerated drug release. In detail, sonication leads to GenPLPF swelling from 329 to 516 nm, while its Young's modulus significantly decreased from 336.78 to 3.93 kPa. Through intravenous injection, relatively rigid GenPLPF_T was able to achieve a high level of accumulation at tumor site by active targeting and long-term blood circulation. Moreover, under sonication at the tumor site, GenPLPF_T became softer with enhanced deformability to achieve deep tumor penetration. In addition, in vivo studies revealed that GenPLPF_T was able to penetrate into the deep area of xenografted tumor with enhanced antitumor efficacy and reduced toxicity. Overall, this peptide nanogel with ultrasound-responsive stiffness demonstrates an effective approach to overcome a series of biological barriers for enhanced deep tumor therapy.

Approaches to Improve Macromolecule and Nanoparticle Accumulation in the Tumor Microenvironment by the Enhanced Permeability and Retention Effect

Passive targeting is the foremost mechanism by which nanocarriers and drug-bearing macromolecules deliver their payload selectively to solid tumors. An important driver of passive targeting is the enhanced permeability and retention (EPR) effect, which is the cornerstone of most carrier-based tumor-targeted drug delivery efforts. Despite the huge number of publications showcasing successes in preclinical animal models, translation to the clinic has been poor, with only a few nano-based drugs currently being used for the treatment of cancers. Several barriers and factors have been adduced for the low delivery efficiency to solid tumors and poor clinical translation, including the characteristics of the nanocarriers and macromolecules, vascular and physiological barriers, the heterogeneity of tumor blood supply which affects the homogenous distribution of nanocarriers within tumors, and the transport and penetration depth of macromolecules and nanoparticles in the tumor matrix. To address the challenges associated with poor tumor targeting and therapeutic efficacy in humans, the identified barriers that affect the efficiency of the enhanced permeability and retention (EPR) effect for macromolecular therapeutics and nanoparticle delivery systems need to be overcome. In this review, approaches to facilitate improved EPR delivery outcomes and the clinical translation of novel macromolecular therapeutics and nanoparticle drug delivery systems are discussed.

PNA-Modified Liposomes Improve the Delivery Efficacy of CAPIRI for the Synergistic Treatment of Colorectal Cancer

Tumor-associated antigen mucin 1 (MUC1) is highly expressed in colorectal cancer and is positively correlated with advanced stage at diagnosis and poor patient outcomes. The combination of irinotecan and capecitabine is standard chemotherapy for metastatic colorectal cancer and is known as XELIRI or CAPIRI, which significantly prolongs the progression-free survival and overall survival of colorectal cancer patients compared to a single drug alone. We previously reported that peanut agglutinin (PNA)-conjugated liposomes showed enhanced drug delivery efficiency to MUC1-positive liver cancer cells. In this study, we prepared irinotecan hydrochloride (IRI) and capecitabine (CAP)-coloaded liposomes modified by peanut agglutinin (IRI/CAP-PNA-Lips) to target MUC1-positive colorectal cancer. The results showed that IRI/CAP-PNA-Lips showed an enhanced ability to target MUC1-positive colorectal cancer cells compared to unmodified liposomes. Treatment with IRI/CAP-PNA-Lips also increased the proportion of apoptotic cells and inhibited the proliferation of colorectal cancer cells. The targeting specificity for tumor cells and the antitumor effects of PNA-modified liposomes were significantly increased in tumor-bearing mice with no severe cytotoxicity to normal tissues. These results suggest that PNA-modified liposomes could provide a new delivery strategy for the synergistic treatment of colorectal cancer with clinical chemotherapeutic agents.

A compound formulation of EGF-modified paclitaxel micelles and EGF-modified emodin micelles enhance the therapeutic effect of ovarian cancer

Ovarian cancer is a serious threat to female health, although the incidence of it is relatively low, its mortality rate remains high due to its intense invasion and metastasis. Therefore, it is urgent to explore new treatment strategies for ovarian cancer. In this study, paclitaxel and emodin were encapsulated in different micelles, and loaded on the surface of the micelles with epidermal growth factor (EGF) as the targeting molecule, made compound formulations in proportion. In this study, EGF-modified paclitaxel micelles and EGF-modified emodin micelles were characterized, their inhibitory effects on SKOV3 cell proliferation and invasion were studied in vivo and in vitro, and its targeting ability was confirmed. The results showed that the shape, particle size, zeta potential, release rate, encapsulation rate, polydispersity index, and other physical and chemical properties of EGF-modified paclitaxel micelles plus EGF-modified emodin micelles meet the requirements, and the modification of EGF on the micelle surface could obviously improve the uptake of SKOV3 cells and inhibit the proliferation of SKOV3 cells. The compound formulation can inhibit the invasion and metastasis of ovarian cancer by inhibiting the expression of hypoxia inducible factor-α, MMP-2, MMP-9, and VE-cadherin. The in vivo studies have also showed significant pharmacodynamics results. These results indicated that EGF-modified paclitaxel micelles plus EGF-modified emodin micelles provide a new strategy for the treatment of ovarian cancer.

An Updated Review on EPR-Based Solid Tumor Targeting Nanocarriers for Cancer Treatment

Simple Summary

One of the important efforts in the treatment of cancers is to achieve targeted drug delivery by nanocarriers to be more effective and reduce adverse effects. However, due to the adverse responses of nanocarriers in clinical trials due to the very weak EPR effects, doubts have been raised in this regard. In this study, an attempt has been made to take a critical look at EPR approaches to enable the convergence of previous papers and the EPR critics to reach an appropriate therapeutic path. Although the effectiveness of EPR is highly variable due to the complex microenvironment of the tumor, there is high hope for cancer treatment by describing new strategies to overcome the challenges of EPR effect. Furthermore, in this paper an attempt was made to provide a reliable path for future to develop cancer therapeutics based on EPR effect.

Abstract

The enhanced permeability and retention (EPR) effect in cancer treatment is one of the key mechanisms that enables drug accumulation at the tumor site. However, despite a plethora of virus/inorganic/organic-based nanocarriers designed to rely on the EPR effect to effectively target tumors, most have failed in the clinic. It seems that the non-compliance of research activities with clinical trials, goals unrelated to the EPR effect, and lack of awareness of the impact of solid tumor structure and interactions on the performance of drug nanocarriers have intensified this dissatisfaction. As such, the asymmetric growth and structural complexity of solid tumors, physicochemical properties of drug nanocarriers, EPR analytical combination tools, and EPR description goals should be considered to improve EPR-based cancer therapeutics. This review provides valuable insights into the limitations of the EPR effect in therapeutic efficacy and reports crucial perspectives on how the EPR effect can be modulated to improve the therapeutic effects of nanomedicine.

Bioinspired and Biomimetic Nanomedicines for Targeted Cancer Therapy

Undesirable side effects and multidrug resistance are the major obstacles in conventional chemotherapy towards cancers. Nanomedicines provide alternative strategies for tumor-targeted therapy due to their inherent properties, such as nanoscale size and tunable surface features. However, the applications of nanomedicines are hampered in vivo due to intrinsic disadvantages, such as poor abilities to cross biological barriers and unexpected off-target effects. Fortunately, biomimetic nanomedicines are emerging as promising therapeutics to maximize anti-tumor efficacy with minimal adverse effects due to their good biocompatibility and high accumulation abilities. These bioengineered agents incorporate both the physicochemical properties of diverse functional materials and the advantages of biological materials to achieve desired purposes, such as prolonged circulation time, specific targeting of tumor cells, and immune modulation. Among biological materials, mammalian cells (such as red blood cells, macrophages, monocytes, and neutrophils) and pathogens (such as viruses, bacteria, and fungi) are the functional components most often used to confer synthetic nanoparticles with the complex functionalities necessary for effective nano-biointeractions. In this review, we focus on recent advances in the development of bioinspired and biomimetic nanomedicines (such as mammalian cell-based drug delivery systems and pathogen-based nanoparticles) for targeted cancer therapy. We also discuss the biological influences and limitations of synthetic materials on the therapeutic effects and targeted efficacies of various nanomedicines.

Nanomaterials in cancer: Reviewing the combination of hyperthermia and triggered chemotherapy

Nanoparticle mediated hyperthermia has been explored as a method to increase cancer treatment efficacy by heating tumours inside-out. With that purpose, nanoparticles have been designed and their properties tailored to respond to external stimuli and convert the supplied energy into heat, therefore inducing damage to tumour cells. Moreover, the combination of hyperthermia with chemotherapy has been described as a more effective strategy due to the synergy between the high temperature and the drug's effects, also associated with a remote controlled and on-demand drug release. In this review, the methods behind nanoparticle mediated hyperthermia, namely material design, external stimuli response and energy conversion will be discussed and critically analysed. We will address the most relevant studies on hyperthermia and temperature triggered drug release for cancer treatment. Finally, the advantages, difficulties and challenges of this therapeutic strategy will be discussed, while giving insight for future developments.

A minimalist and robust chemo-photothermal nanoplatform capable of augmenting autophagy-modulated immune response against breast cancer

Previously used in anti-fungal therapy, itraconazole has now been shown to be successful in treating advanced breast cancer (NCT00798135). However, its poor solubility still restricts its application in clinical treatment. There is therefore an urgent need for combined methods to enhance the therapeutic effect of itraconazole (IC) in breast cancer treatment. With this goal, co-assembled IC/IR820 NPs with synergistic photonic hyperthermia and itraconazole payloads have been constructed to overcome these shortcomings. The IC/IR820 NPs show an enhanced therapeutic effect on breast cancer by inducing reactive oxygen species (ROS)-mediated apoptosis and autophagic death. Further evaluation in a mouse model has shown impressive effects of the IC/IR820 NPs on both inhibiting tumor metastasis and activating immunity to prevent tumor recurrence. Mechanistically, itraconazole may promote both tumor cell antigen presentation through autophagy and the activation of dendritic cells to induce an immune response, which displays a synergistic effect with the immune response generated by photothermal therapy to inhibit tumor recurrence. This strategy of combining itraconazole and IR820 into one minimalist and robust nanoplatform through co-assembly results in excellent therapeutic efficacy, suggesting its potential application as an alternative method for the clinical treatment of breast cancer.

pH-sensitive hyaluronic acid-targeted prodrug micelles constructed via a one-step reaction for enhanced chemotherapy

Although many chemotherapy prodrugs have been developed for tumor therapy, non-targeted delivery, uncontrolled release and tedious construction procedure of prodrugs still limit their clinical application in tumor treatment. In this work, hyaluronic acid (HA) which has tumor-targeting ability was used to conjugate to antitumor drug podophyllotoxin (PPT) to construct a pH-sensitive prodrug named HA-CO-O-PPT just via a one-step esterification reaction. The HA-CO-O-PPT spontaneously assembled into nano spherical micelles in aqueous medium, which had outstanding serum stability and blood compatibility. The obtained prodrug micelles (named HP micelles) exhibited a pH-responsive drug release mode with cumulative release reaching 81.2% due to their dissociation in response to acid stimulus, and had a high cellular uptake efficiency beyond 97% owing to HA receptor-mediated targeting. Furthermore, it was found that the prodrug micelles showed excellent antitumor activities in vivo with the tumor inhibition ratio up to 85% and negligible systemic toxicity. Accordingly, the pH-responsive HP micelles constructed by a simple one-step reaction, could be a promising candidate as a chemotherapeutic agent for cancer therapy.

Nanodelivery of nucleic acids

There is growing need for a safe, efficient, specific and non-pathogenic means for delivery of gene therapy materials. Nanomaterials for nucleic acid delivery offer an unprecedented opportunity to overcome these drawbacks; owing to their tunability with diverse physico-chemical properties, they can readily be functionalized with any type of biomolecules/moieties for selective targeting. Nucleic acid therapeutics such as antisense DNA, mRNA, small interfering RNA (siRNA) or microRNA (miRNA) have been widely explored to modulate DNA or RNA expression Strikingly, gene therapies combined with nanoscale delivery systems have broadened the therapeutic and biomedical applications of these molecules, such as bioanalysis, gene silencing, protein replacement and vaccines. Here, we overview how to design smart nucleic acid delivery methods, which provide functionality and efficacy in the layout of molecular diagnostics and therapeutic systems. It is crucial to outline some of the general design considerations of nucleic acid delivery nanoparticles, their extraordinary properties and the structure-function relationships of these nanomaterials with biological systems and diseased cells and tissues.

Magnetic, biocompatible FeCO3 nanoparticles for T2-weighted magnetic resonance imaging of in vivo lung tumors

Background

Late diagnosis of lung cancer is one of the leading causes of higher mortality in lung cancer patients worldwide. Significant research attention has focused on the use of magnetic resonance imaging (MRI) based nano contrast agents to efficiently locate cancer tumors for surgical removal or disease diagnostics. Although contrast agents offer significant advantages, further clinical applications require improvements in biocompatibility, biosafety and efficacy.

Results

To address these challenges, we fabricated ultra-fine Iron Carbonate Nanoparticles (FeCO₃ NPs) for the first time via modified literature method. Synthesized NPs exhibit ultra-fine size (~ 17 nm), good dispersibility and excellent stability in both aqueous and biological media. We evaluated the MR contrast abilities of FeCO₃ NPs and observed remarkable T2 weighted MRI contrast in a concentration dependent manner, with a transverse relaxivity (r2) value of 730.9 ± 4.8 mM⁻¹ S⁻¹at 9.4 T. Moreover, the r2 values of present FeCO₃ NPs are respectively 1.95 and 2.3 times higher than the clinically approved contrast agents Resovist^® and Friedx at same 9.4 T MR scanner. FeCO₃ NPs demonstrate an enhanced T2 weighted contrast for in vivo lung tumors within 5 h of post intravenous administration with no apparent systemic toxicity or induction of inflammation observed in in vivo mice models.

Conclusion

The excellent biocompatibility and T2 weighted contrast abilities of FeCO₃ NPs suggest potential for future clinical use in early diagnosis of lung tumors.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01355-3.

Multifunctional Nanomaterials for Ferroptotic Cancer Therapy

Patient outcomes from the current clinical cancer therapy remain still far from satisfactory. However, in recent years, several biomedical discoveries and nanotechnological innovations have been made, so there is an impetus to combine these with conventional treatments to improve patient experience and disease prognosis. Ferroptosis, a term first coined in 2012, is an iron-dependent regulated cell death (RCD) based on the production of reactive oxygen species (ROS) and the consequent oxidization of polyunsaturated fatty acids (PUFAs). Many nanomaterials that can induce ferroptosis have been explored for applications in cancer therapy. In this review, we summarize the recent developments in ferroptosis-based nanomaterials for cancer therapy and discuss the future of ferroptosis, nanomedicine, and cancer therapy.

Pathophysiological and pharmacological considerations to improve the design and application of antibody-drug conjugates

Antibody-drug conjugates (ADC) have emerged as one of the pillars of clinical disease management in oncology. The biggest hurdle to widespread development and application of ADCs has been a narrow therapeutic index. Advances in antibody technologies and formats as well as novel linker and payload chemistries have begun to facilitate structural improvements to ADCs. However, the interplay of structural characteristics with physiologic and pharmacologic factors determining therapeutic success has garnered less attention. This review elaborates on the pharmacology of ADCs, the pathophysiology of cancerous tissues, and the reciprocal consequences on ADC properties and functions. While most currently approved ADCs utilize either microtubule inhibition or DNA damage as primary mechanisms of action, we present arguments to expand this repertoire and highlight the need for payload mechanisms that exploit disease-specific vulnerabilities. We promote the idea that the choice of antibody format, targeting antigen, linker properties, and payload of an ADC should be deliberately fit for purpose by taking the pathophysiology of disease and the specific pharmacology of the drug entity into account, thus allowing a higher probability of clinical success.