One-step construction of ferritin encapsulation drugs for cancer chemotherapy

Novel engineered HER2 specific recombinant protein nanocages for targeted drug delivery

Protein nanocages resemble natural biomimetic carriers and can be engineered to act as targeted delivery systems, making them an attractive option for various drug delivery and biomedical applications. Our research investigated the genetic link of a specific anti-HER2 peptide (LTVSPWY) to the exposed N-terminal region of the maize (Zea mays) ferritin 1 (ZmFer1) protein nanocage, employing either a 7-amino acid (for LTVS-ZmFer1) or 16-amino acid (for LTVS-L-ZmFer1) linker. We utilized a heat treatment method to load the chemotherapeutic drug doxorubicin into the protein nanocage. The construct with the longer linker (LTVS-L) produced a greater amount of soluble protein nanocage and was selected for further experiments. The average size, polydispersity index, and zeta potential of the engineered protein nanocage were 19.01 nm, 0.168, and - 2.13 mV, respectively. The LTVS-L-ZmFer1 protein nanocage exhibited excellent thermal stability, withstanding temperatures up to 100 °C with only partial denaturation. Furthermore, we observed that cellular uptake of the LTVS-L-ZmFer1 protein nanocages in HER2-positive breast cancer cells was significantly higher compared to ZmFer1 after labeling with FITC (fluorescein isothiocyanate) (P-value = 0.0001). In addition, we observed a significant decrease in the viability of SKBR3 cells when treated with DOX-loaded LTVS-L-ZmFer1 protein nanocages compared to cells treated with DOX-loaded ZmFer1 protein nanocages. Therefore, this new treatment strategy may prove to be an effective way to reduce both the side effects and toxicity associated with conventional cancer treatments in patients with HER2-positive breast cancer.

Improvement of physicochemical properties of lycopene by the self-assembly encapsulation of recombinant ferritin GF1 from oyster (Crassostrea gigas)

BACKGROUND

Lycopene (LYC), a carotenoid found in abundance in ripe red fruits, exhibits higher singlet oxygen quenching activity than other carotenoids. However, the stability of LYC is extremely poor due to its high double-bond content. In this paper, a nano-encapsulation strategy based on highly stable marine-derived ferritin GF1 nanocages was used to improve the thermal stability and oxidation resistance of LYC, thereby boosting its functional effectiveness and industrial applicability.

RESULTS

The preparation of GF1-LYC nanoparticles benefited from the pH-responsive reversible self-assembly of GF1 to capture LYC molecules into GF1 cavities with a LYC-to-protein ratio of 51 to 1. After the encapsulation of the LYC, the reassembled GF1 nanocages maintained intact morphology and good monodispersity. The GF1-LYC nanoparticles incorporated the characteristic LYC peaks in spectrograms, and their powder form contained the crystalline form of LYC. Molecular docking revealed that LYC bound with the inner triple-axis channel areas of GF1, interacting with VAL139, LYS72, LYS65, TYR69, PHE129, HIS133, HIS62, and TYR134 amino acids through hydrophobic bonds. Fourier transform infrared spectroscopy also demonstrated the bonding of GF1 and LYC. In comparison with free LYC, GF1 reduced the thermal degradation of encapsulated LYC at 37 °C significantly and maintained the 2,2-Diphenyl-1-picrylhydrazyl (DPPH)-scavenging ability of LYC.

CONCLUSION

As expected, the water solubility, thermal stability, and antioxidant capacity of encapsulated LYC from GF1-LYC nanoparticles was notably improved in comparison with free LYC, indicating that the shell-like marine ferritin nanoplatform might enhance the stable delivery of LYC and promote its utilization in the field of food nutrition and in other industries. © 2023 Society of Chemical Industry.

Heat sensitive E-helix cut ferritin nanocages for facile and high-efficiency loading of doxorubicin

Ferritin possesses a stable and uniform cage structure, along with tumor-targeting properties and excellent biocompatibility, making it a promising drug delivery vehicle. However, the current ferritin drug loading strategy involves complex steps and harsh reaction conditions, resulting in low yield and recovery of drug loading, which limits the clinical application prospects of ferritin nanomedicine. In this study, we utilized the high-efficiency heat-sensitivity of the multiple channel switch structures of the E-helix-cut ferritin mutant (Ecut-HFn) and Cu2+ assistance to achieve high-efficiency loading of chemotherapeutic drugs in a one-step process at low temperatures. This method features mild reaction conditions (45 °C), high loading efficiency (about 110 doxorubicin (Dox) per Ecut-HFn), and improved protein and Dox recovery rates (with protein recovery rate around 94 % and Dox recovery rate reaching up to 45 %). The prepared ferritin-Dox particles (Ecut-HFn-Cu-Dox) exhibit a uniform size distribution, good stability, and retain the natural tumor targeting ability of ferritin. Overall, this temperature-controlled drug loading strategy utilizing heat-sensitivity ferritin mutants is energy-saving, environmentally friendly, efficient, and easy to operate, offering a new perspective for scaling up the industrial production of ferritin drug carriers.

Hydrophobicity-enhanced ferritin nanoparticles for efficient encapsulation and targeted delivery of hydrophobic drugs to tumor cells

Ferritin, a naturally occurring iron storage protein, has gained significant attention as a drug delivery platform due to its inherent biocompatibility and capacity to encapsulate therapeutic agents. In this study, we successfully genetically engineered human H ferritin by incorporating 4 or 6 tryptophan residues per subunit, strategically oriented towards the inner cavity of the nanoparticle. This modification aimed to enhance the encapsulation of hydrophobic drugs into the ferritin cage. Comprehensive characterization of the mutants revealed that only the variant carrying four tryptophan substitutions per subunit retained the ability to disassemble and reassemble properly. As a proof of concept, we evaluated the loading capacity of this mutant with ellipticine, a natural hydrophobic indole alkaloid with multimodal anticancer activity. Our data demonstrated that this specific mutant exhibited significantly higher efficiency in loading ellipticine compared to human H ferritin. Furthermore, to evaluate the versatility of this hydrophobicity-enhanced ferritin nanoparticle as a drug carrier, we conducted a comparative study by also encapsulating doxorubicin, a commonly used anticancer drug. Subsequently, we tested both ellipticine and doxorubicin-loaded nanoparticles on a promyelocytic leukemia cell line, demonstrating efficient uptake by these cells and resulting in the expected cytotoxic effect.

Recombinant ferritins for multimodal nanomedicine

In all living organisms, ferritins are a group of proteins important for maintaining iron homeostasis. Increasing amount of studies has shown that recombinant ferritins can be widely used in multimodal nanomedicine, especially for anticancer treatment and vaccination. Recombinant particles prepared by fusing viral proteins and ferritin subunits produce a better immune response and higher antibody titres. Moreover, actively-targeted ferritin nanoparticles can recognise receptors and deliver natural or chemical drugs specifically to the tumour tissue. In addition, ferritin-linked or loaded with contrast agents or fluorescent dyes can be used as multimodal particles useful cancer theranostics. In this review, we fully summarised the unitisation of recombinant ferritins in multimodal nanomedicine. The research progress of using recombinant ferritins as nanovaccines, nanozymes, and bioengineered nanocarriers for targeted therapy and bioimaging is emphasised.

Protein-based Nanoparticles: From Drug Delivery to Imaging, Nanocatalysis and Protein Therapy

Proteins and enzymes are versatile biomaterials for a wide range of medical applications due to their high specificity for receptors and substrates, high degradability, low toxicity, and overall good biocompatibility. Protein nanoparticles are formed by the arrangement of several native or modified proteins into nanometer-sized assemblies. In this review, we will focus on artificial nanoparticle systems, where proteins are the main structural element and not just an encapsulated payload. While under natural conditions, only certain proteins form defined aggregates and nanoparticles, chemical modifications or a change in the physical environment can further extend the pool of available building blocks. This allows the assembly of many globular proteins and even enzymes. These advances in preparation methods led to the emergence of new generations of nanosystems that extend beyond transport vehicles to diverse applications, from multifunctional drug delivery to imaging, nanocatalysis and protein therapy.

Widespread in vivo efficacy of The-0504: A conditionally-activatable nanoferritin for tumor-agnostic targeting of CD71-expressing cancers

Background

Cancer is still among the leading causes of death all over the world. Improving chemotherapy and minimizing associated toxicities are major unmet medical needs. Recently, we provided a preliminary preclinical evaluation of a human ferritin (HFt)-based drug carrier (The-0504) that selectively delivers the wide-spectrum topoisomerase I inhibitor Genz-644282 to CD71-expressing tumors. The-0504 has so far been evaluated on four different human tumor xenotransplant models (breast, colorectal, pancreatic and liver cancers).

Methods

Herein, we extend our studies, by: (a) testing DNA damage in vitro, (b) treating eight additional tumor xenograft models in vivo with The-0504; (c) performing pharmacokinetic (PK) studies in rats; and (d) evaluating The-0504 anti-tumor xenotransplant efficacy by optimizing its administration schedule based on PK considerations.

Results

Immunofluorescence demonstrated that The-0504 induces foci expressing the DNA double-strand break marker γH2AX. Expression increases up to 4-fold and is more persistent as compared to free Genz-644282. In vivo studies confirmed a remarkable anti-tumor activity of The-0504, resulting in tumor eradication in most murine xenograft models, regardless of embryological origin (e.g. epithelial, mesenchymal or neuroendocrine), and molecular subtypes. PK studies demonstrated a long persistence of The-0504 in rat serum (half-life of about 40 h as compared to 15 h of the free drug), with a 400-fold increase in peak concentrations as compared to the free drug. On this basis, we reduced The-0504 administration frequency from twice to once per week, with no appreciable loss in therapeutic efficacy in mice.

Conclusion

The results presented here confirm that The-0504 is highly active against several human tumor xenotransplants, even when administered less frequently than previously reported. The-0504 may be a good candidate for further clinical development in a tumor histotype-agnostic setting.

Overcoming Non-Specific Interactions for Efficient Encapsulation of Doxorubicin in Ferritin Nanocages for Targeted Drug Delivery

Due to its beneficial pharmacological properties, ferritin (Ftn) is considered as an interesting drug delivery vehicle to alleviate the cardiotoxicity of doxorubicin (DOX) in chemotherapy. However, the encapsulation of DOX in Ftn suffers from heavy precipitation and low protein recovery yield which limits its full potential. Here, a new DOX encapsulation strategy by cysteine-maleimide conjugation is proposed. In order to demonstrate that this strategy is more efficient compared to the other approaches, DOX is encapsulated in Ftn variants carrying different surface charges. Furthermore, in contrast to the common belief, this data show that DOX molecules are also found to bind non-specifically to the surface of Ftn. This can be circumvented by the use of Tris(2-carboxyethyl)phosphine (TCEP) during encapsulation or by washing with acidic buffer. The biocompatibility studies of the resulting DOX Ftn variants in MCF-7 and MHS cancer cells shows a complex relationship between the cytotoxicity, the DOX loading and the different surface charges of Ftn. Further investigation on the cell uptake mechanism provides reasonable explanations for the cytotoxicity results and reveals that surface charging of Ftn hinders its transferrin receptor 1 (TfR-1) mediated cellular uptake in MCF-7 cells.

Optical Monitoring of In Situ Iron Loading into Single, Native Ferritin Proteins

Ferritin is a protein that stores and releases iron to prevent diseases associated with iron dysregulation in plants, animals, and bacteria. The conversion between iron-loaded holo-ferritin and empty apo-ferritin is an important process for iron regulation. To date, studies of ferritin have used either ensemble measurements to quantify the characteristics of a large number of proteins or single-molecule approaches to interrogate labeled or modified proteins. Here we demonstrate the first real-time study of the dynamics of iron ion loading and biomineralization within a single, unlabeled ferritin protein. Using optical nanotweezers, we trapped single apo- and holo-ferritins indefinitely, distinguished one from the other, and monitored their structural dynamics in real time. The study presented here deepens the understanding of the iron uptake mechanism of ferritin proteins, which may lead to new therapeutics for iron-related diseases.

Simple plant-based production and purification of the assembled human ferritin heavy chain as a nanocarrier for tumor-targeted drug delivery and bioimaging in cancer therapy

Nanoparticles are used as carriers for the delivery of drugs and imaging agents. Proteins are safer than synthetic nanocarriers due to their greater biocompatibility and the absence of toxic degradation products. In this context, ferritin has the additional benefit of inherently targeting the membrane receptor transferrin 1, which is overexpressed by most cancer cells. Furthermore, this self-assembling multimeric protein can be loaded with more than 2000 iron atoms, as well as drugs, contrast agents, and other cargos. However, recombinant ferritin currently costs ~3.5 million € g^-1 , presumably because the limited number of producers cannot meet demand, making it generally unaffordable as a nanocarrier. Because plants can produce proteins at very-large-scale, we developed a simple, proof-of-concept process for the production of the human ferritin heavy chain by transient expression in Nicotiana benthamiana. We optimized the protein yields by screening different compartments and 5'-untranslated regions in PCPs, and selected the best-performing construct for production in differentiated plants. We then established a rapid and scalable purification protocol by combining pH and heat treatment before extraction, followed by an ultrafiltration/diafiltration size-based separation process. The optimized process achieved ferritin levels of ~40 mg kg^-1 fresh biomass although depth filtration limited product recovery to ~7%. The purity of the recombinant product was >90% at costs ~3% of the current sales price. Our method therefore allows the production of affordable ferritin heavy chain as a carrier for therapeutic and diagnostic agents, which is suitable for further stability and functionality testing in vitro and in vivo.

Tailored Functionalized Protein Nanocarriers for Cancer Therapy: Recent Developments and Prospects

Recently, the potential use of nanoparticles for the targeted delivery of therapeutic and diagnostic agents has garnered increased interest. Several nanoparticle drug delivery systems have been developed for cancer treatment. Typically, protein-based nanocarriers offer several advantages, including biodegradability and biocompatibility. Using genetic engineering or chemical conjugation approaches, well-known naturally occurring protein nanoparticles can be further prepared, engineered, and functionalized in their self-assembly to meet the demands of clinical production efficiency. Accordingly, promising protein nanoparticles have been developed with outstanding tumor-targeting capabilities, ultimately overcoming multidrug resistance issues, in vivo delivery barriers, and mimicking the tumor microenvironment. Bioinspired by natural nanoparticles, advanced computational techniques have been harnessed for the programmable design of highly homogenous protein nanoparticles, which could open new routes for the rational design of vaccines and drug formulations. The current review aims to present several significant advancements made in protein nanoparticle technology, and their use in cancer therapy. Additionally, tailored construction methods and therapeutic applications of engineered protein-based nanoparticles are discussed.

Construction Protocol of Drug-Protein Cage Complexes for Drug Delivery System

Ferritin is one of the most promising drug delivery system (DDS) carriers because of its uniform nanosize, biodistribution, efficient cellular uptake, and biocompatibility. Conventionally, a disassembly/reassembly method that requires pH change has been used for the encapsulation of molecules in ferritin protein nanocages. Recently, a one-step method in which a complex of ferritin and a targeted drug was obtained by incubating the mixture at an appropriate pH, was established. Here, we describe two types of protocols, the conventional disassembly/reassembly method, and the novel one-step method for the construction of a ferritin-encapsulated drug using doxorubicin as an example molecule.

Synergistic effect of GF9 and streptomycin on relieving gram-negative bacteria-induced sepsis

Triggering receptor expressed on myeloid cells-1 (TREM-1) regulates inflammation and promotes a vigorous immune response. GF9 is one of the peptides that inhibit the mTREM-1 signaling pathway, thus reducing the inflammatory mediators in diseases including sepsis. Nanotechnology could offer a new complementary strategy for diseases. Streptomycin is also one treatment of sepsis. However, the role of nanoparticles delivered GF9 combined with streptomycin on sepsis had never been discovered. In the present study, cecal ligation and puncture (CLP) and lipopolysaccharide [LPS, Escherichia coli (E. coli) O111:B4] sepsis models were constructed. SDS-PAGE was used to evaluate the size of nano drugs; Western blot was used to detect the protein levels of MMP2 and TREM-1 in cells. The levels of TNF-α and IL-6 were detected by ELISA. Histopathological changes were observed by HE staining. And the nanomedicines of GF9-HFn/Str were successfully constructed. The size of GF9-HFn/Str is 36 kD. The ferritin-based nanoparticle plays a vital role in delivering streptomycin into cells and tissues. GF9 (1.6 μM) and streptomycin (40 μM) co-delivery nanomedicine showed a better effect on promoting overall survival, decreasing E. coli, significantly suppressed the expression levels of inflammatory factors (TNF-α and IL-6), and can reduce lung injury. Our study demonstrated that combination delivery of nanomedicine GF9 and streptomycin have a better effect on overall survival rate, anti-inflammatory, and anti-bacterial in sepsis. Our present study revealed a new potential therapeutic method for sepsis.

Application Perspectives of Nanomedicine in Cancer Treatment

Cancer is a disease that seriously threatens human health. Based on the improvement of traditional treatment methods and the development of new treatment modes, the pattern of cancer treatment is constantly being optimized. Nanomedicine plays an important role in these evolving tumor treatment modalities. In this article, we outline the applications of nanomedicine in three important tumor-related fields: chemotherapy, gene therapy, and immunotherapy. According to the current common problems, such as poor targeting of first-line chemotherapy drugs, easy destruction of nucleic acid drugs, and common immune-related adverse events in immunotherapy, we discuss how nanomedicine can be combined with these treatment modalities, provide typical examples, and summarize the advantages brought by the application of nanomedicine.

Simultaneous quantification of oligo-nucleic acids and a ferritin nanocage by size-exclusion chromatography hyphenated to inductively coupled plasma mass spectrometry for developing drug delivery systems

An analytical methodology, which can quantify nucleic acids, ferritin nanocages, and their complexes in a single injection, was established by means of size-exclusion chromatography hyphenated with inductively coupled plasma mass spectrometry (SEC-ICP-MS). In this study, several oligo-nucleic acids and ferritin (a human-derived cage-shaped protein) were used as model compounds of nucleic acid drugs (NAD) and drug delivery system (DDS) carriers, respectively. A fraction based on the nucleic acid-ferritin complex was completely distinguished from one based on free nucleic acids by SEC separation. The nucleic acids and ferritin were quantified based on the number of phosphorus and sulfur atoms, respectively. The quantification was carried out by an external calibration method using a series of elemental standard solutions without preparing designated standard materials for each drug candidate. The analytical performance, including sensitivity and accuracy, was evaluated to be appropriate for evaluating the medicines already launched in the market. As demonstrated in the latter part of this study, the encapsulation mechanism is possibly regulated by not only the averaged molecular size of nucleic acids but also the surface charge related to the number of (deoxy-) ribonucleotides. We believe that the methodology presented in this study has the potential to accelerate the development of new modalities based on NAD-DDS to realize therapies in the future.

An Optimally Fabricated Platform Guides Cancer-Specific Activation of Chemotherapeutic Drugs and Toxicity-free Cancer Treatment

Cancer chemotherapeutic drugs such as doxorubicin, mitomycin C, and gemcitabine, which are mostly small synthetic molecules, are still clinically useful for cancer treatment. However, despite considerable therapeutic efficacy, severe toxicity-associated problems, which are mainly caused by the non-specific mode of action such as chromosomal DNA damage and interference in the DNA replication even in normal cells, remain unresolved and a major challenge for safer and thus more widespread adoption of chemotherapy. Here we developed an innovative platform through beneficially integrating core peptide units into highly-ordered, stable, and flexibly guest-adaptable structure of apoferritin, which simultaneously fulfills high-capacity loading of chemotherapeutic drugs compared  with the case of FDA-approved antibody-drug conjugates, efficient drug targeting to cancer cells, and cancer cell-specific drug release and activation. This approach dramatically reduced drug toxicity to normal cells, significantly enhanced efficacy in in vivo cancer treatment without toxicity to normal organs of mice, and thus is expected to open up a novel clinical route to break through the limits of current cancer chemotherapy. This article is protected by copyright. All rights reserved.

Rational design of engineered H-ferritin nanoparticles with improved siRNA delivery efficacy across an in vitro model of the mouse BBB

Gene therapy holds tremendous potential for the treatment of incurable brain diseases including Alzheimer's disease (AD), stroke, glioma, and Parkinson's disease. The main challenge is the lack of effective gene delivery systems traversing the blood-brain barrier (BBB), due to the complex microvessels present in the brain which restrict substances from the circulating blood passing through. Recently, increasing efforts have been made to develop promising gene carriers for brain-related disease therapies. One such development is the self-assembled heavy chain ferritin (HFn) nanoparticles (NPs). HFn NPs have a unique hollow spherical structure that can encapsulate nucleic acid drugs (NADs) and specifically bind to cancer cells and BBB endothelial cells (BBB ECs) via interactions with the transferrin receptor 1 (TfR1) overexpressed on their surfaces, which increases uptake through the BBB. However, the gene-loading capacity of HFn is restricted by its limited interior volume and negatively charged inner surface; therefore, these drawbacks have prompted the demand for strategies to remould the structure of HFn. In this work, we analyzed the three-dimensional (3D) structure of HFn using Chimera software (v 1.14) and developed a class of internally cationic HFn variants (HFn+ NPs) through arginine mutation on the lumenal surface of HFn. These HFn+ NPs presented powerful electrostatic forces in their cavities, and exhibited higher gene encapsulation efficacy than naive HFn. The top-performing candidate, HFn2, effectively delivered siRNA to glioma cells after traversing the BBB and achieved the highest silencing efficacy among HFn+ NPs. Overall, our findings demonstrate that HFn+ NPs obtained by this genetic engineering method provide critical insights into the future development of nucleic acid delivery carriers with BBB-crossing ability.

Selective delivery of curcumin to breast cancer cells by self-targeting apoferritin nanocages with pH-responsive and low toxicity

Breast cancer is prevalent and diverse with significantly high incidence and mortality rates. Curcumin (Cur), a polyphenol component of turmeric, has been widely recognized as having strong anti-breast cancer activity. However, its anti-cancer efficiency is largely impaired by some of its concomitant negative properties, including its poor solubility, low cellular uptake, and severe reported side effects. Hence, the necessity arises to develop a novel low-toxic and high-efficiency targeting drug delivery system (DDS). In this study, we developed a pH-sensitive tumor self-targeting DDS (Cur@HFn) based on self-assembled HFn loaded with Cur, in which Cur was encapsulated into HFn cavity by using a disassembly/reassembly strategy, and the Cur@HFn was characterized by ultraviolet–visible (UV–vis), dynamic light scattering (DLS), and transmission electron microscope (TEM). A variety of breast cancer cell models were built to evaluate cytotoxicity, apoptosis, targeting properties, and uptake mechanism of the Cur@HFn. The pharmacodynamics was also evaluated in tumor (4T1) bearing mice after intravenous injection. In vitro release experiments showed that Cur@HFn is pH sensitive and shows sustained drug release under slightly acidic conditions. Compared with Cur, Cur@HFn has stronger cytotoxicity, cellular uptake, and targeting performance. Our study supported that Cur@HFn has a higher in vivo therapeutic effect and lower systemic toxicity. The safety evaluation results indicated that Cur@HFn has no hematotoxicity, hepatotoxicity, and nephrotoxicity. The findings of the present study showed that the Cur@HFn has been successfully prepared and has potential application value in the treatment of breast cancer.

Ferritinophagy and α-Synuclein: Pharmacological Targeting of Autophagy to Restore Iron Regulation in Parkinson's Disease

A major hallmark of Parkinson’s disease (PD) is the fatal destruction of dopaminergic neurons within the substantia nigra pars compacta. This event is preceded by the formation of Lewy bodies, which are cytoplasmic inclusions composed of α-synuclein protein aggregates. A triad contribution of α-synuclein aggregation, iron accumulation, and mitochondrial dysfunction plague nigral neurons, yet the events underlying iron accumulation are poorly understood. Elevated intracellular iron concentrations up-regulate ferritin expression, an iron storage protein that provides cytoprotection against redox stress. The lysosomal degradation pathway, autophagy, can release iron from ferritin stores to facilitate its trafficking in a process termed ferritinophagy. Aggregated α-synuclein inhibits SNARE protein complexes and destabilizes microtubules to halt vesicular trafficking systems, including that of autophagy effectively. The scope of this review is to describe the physiological and pathological relationship between iron regulation and α-synuclein, providing a detailed understanding of iron metabolism within nigral neurons. The underlying mechanisms of autophagy and ferritinophagy are explored in the context of PD, identifying potential therapeutic targets for future investigation.

The Role of Iron in Cancer Progression

Iron is an essential trace element for the human body, and its deficiency or excess can induce a variety of biological processes. Plenty of evidences have shown that iron metabolism is closely related to the occurrence and development of tumors. In addition, iron plays an important role in cell death, which is very important for the development of potential strategies for tumor treatment. Here, we reviewed the latest research about iron metabolism disorders in various types of tumors, the functions and properties of iron in ferroptosis and ferritinophagy, and new opportunities for iron-based on treatment methods for tumors, providing more information regarding the prevention and treatment of tumors.

Blocking effect of ferritin on the ryanodine receptor-isoform 2

Iron, an essential element for most living organism, participates in a wide variety of physiological processes. Disturbance in iron homeostasis has been associated with numerous pathologies, particularly in the heart and brain, which are the most susceptible organs. Under iron-overload conditions, the generation of reactive oxygen species leads to impairment in Ca2+ signaling, fundamentally implicated in cardiac and neuronal physiology. Since iron excess is accompanied by increased expression of iron-storage protein, ferritin, we examined whether ferritin has an effect on the ryanodine receptor - isoform 2 (RYR2), which is one of the major components of Ca2+ signaling. Using the method of planar lipid membranes, we show that ferritin induced an abrupt, permanent blockage of the RYR2 channel. The ferritin effect was strongly voltage dependent and competitively antagonized by cytosolic TEA+, an impermeant RYR2 blocker. Our results collectively indicate that monomeric ferritin highly likely blocks the RYR2 channel by a direct electrostatic interaction within the wider region of the channel permeation pathway.

Advances in the application of nanotechnology in reducing cardiotoxicity induced by cancer chemotherapy

Advances in the development of anti-tumour drugs and related technologies have resulted in a significant increase in the number of cancer survivors. However, the incidence of chemotherapy-induced cardiotoxicity (CIC) has been rising continuously, threatening their long-term survival. The integration of nanotechnology and biomedicine has brought about an unprecedented technological revolution and has promoted the progress of anti-tumour therapy. In this review, we summarised the possible mechanisms of CIC, evaluated the role of nanoparticles (including liposomes, polymeric micelles, dendrimers, and hydrogels) as drug carriers in preventing cardiotoxicity and proposed five advantages of nanotechnology in reducing cardiotoxicity: Liposomes cannot easily penetrate the heart's endothelial barrier; optimized delivery strategies reduce distribution in important organs, such as the heart; targeting the tumour microenvironment and niche; stimulus-responsive polymer nano-drug carriers rapidly iterate; better economic benefits were obtained. Nanoparticles can effectively deliver chemotherapeutic drugs to tumour tissues, while reducing the toxicity to heart tissues, and break through the dilemma of existing chemotherapy to a certain extent. It is important to explore the interactions between the physicochemical properties of nanoparticles and optimize the highly specific tumour targeting strategy in the future.

Bioengineered Ferritin Nanocarriers for Cancer Therapy

Ferritin naturally exists in most organisms and can specifically recognize the transferrin 1 receptor (TfR1), which is generally highly expressed on various types of tumor cells. The pH dependent reversible assembling and disassembling property of ferritin renders it as a suitable candidate for encapsulating a variety of anticancer drugs and imaging probes. Ferritins external surface is chemically and genetically modifiable which can serve as attachment site for tumor specific targeting peptides or moieties. Moreover, the biological origin of these protein cages makes it a biocompatible nanocarrier that stabilizes and protects the enclosed particles from the external environment without provoking any toxic or immunogenic responses. Recent studies, further establish ferritin as a multifunctional nanocarrier for targeted cancer chemotherapy and phototherapy. In this review, we introduce the favorable characteristics of ferritin drug carriers, the specific targeted surface modification and a multifunctional nanocarriers combined chemotherapy with phototherapy for tumor treatment. Taken together, ferritin is a potential ideal base of engineered nanoparticles for tumor therapy and still needs to explore more on its way.