Ferritins Research Articles

Anticancer Tetranuclear Cu(I) Complex Catalyzes a Click Reaction to Synthesize a Chemotherapeutic Agent in situ to Achieve Targeted Dual-Agent Combination Therapy for Cancer.

To develop next-generation metal-based drugs and dual-drug combination therapy for cancer, we proposed to develop a copper (Cu) complex that exerts anticancer function by integrating chemotherapy, immunotherapy and catalyzes a click reaction for the in situ synthesis of a chemotherapeutic agent, thereby achieving targeted dual-agent combination therapy. We designed and synthesized a tetranuclear Cu(I) complex (Cu4) with remarkable cytotoxicity and notable catalytic ability for the in situ synthesis of a chemotherapeutic agent via Cu(I)-catalyzed azide-alkyne 1,3-cycloaddition (CuAAC). We also constructed an apoferritin (AFt)-Cu4 nanoparticles (NPs) delivery system. Aft-Cu4 NPs not only showed an enhanced performance of tumor growth inhibition, but also improved the targeting ability and reduced the systemic toxicity of Cu4 in vivo. Importantly, the anticancer effect was enhanced by combining the Aft-Cu4 NPs with the resveratrol analogue obtained from the CuAAC reaction in situ. Finally, we revealed the anticancer mechanism of the Cu4/Aft-Cu4 NPs, which involves both cuproptosis and cuproptosis-induced systemic immune response.

Anticancer Tetranuclear Cu(I) Complex Catalyzes a Click Reaction to Synthesize a Chemotherapeutic Agent in situ to Achieve Targeted Dual‐Agent Combination Therapy for Cancer

AbstractTo develop next‐generation metal‐based drugs and dual‐drug combination therapy for cancer, we proposed to develop a copper (Cu) complex that exerts anticancer function by integrating chemotherapy, immunotherapy and catalyzes a click reaction for the in situ synthesis of a chemotherapeutic agent, thereby achieving targeted dual‐agent combination therapy. We designed and synthesized a tetranuclear Cu(I) complex (Cu4) with remarkable cytotoxicity and notable catalytic ability for the in situ synthesis of a chemotherapeutic agent via Cu(I)‐catalyzed azide‐alkyne 1,3‐cycloaddition (CuAAC). We also constructed an apoferritin (AFt)‐Cu4 nanoparticles (NPs) delivery system. Aft‐Cu4 NPs not only showed an enhanced performance of tumor growth inhibition, but also improved the targeting ability and reduced the systemic toxicity of Cu4 in vivo. Importantly, the anticancer effect was enhanced by combining the Aft‐Cu4 NPs with the resveratrol analogue obtained from the CuAAC reaction in situ. Finally, we revealed the anticancer mechanism of the Cu4/Aft‐Cu4 NPs, which involves both cuproptosis and cuproptosis‐induced systemic immune response.

Developing an Arene Binuclear Ruthenium(II) Complex to Induce Ferroptosis and Activate the cGAS-STING Pathway: Targeted Inhibiting Growth and Metastasis of Triple Negative Breast Cancer.

To effectively inhibit the growth and metastasis of triple-negative breast cancer (TNBC), we developed a high-efficiency and low-toxicity arene ruthenium (Ru) complex based on apoferritin (AFt). To achieve this, we optimized a series of Ru(II) 1,10-phenanthroline-2,9-diformaldehyde thiosemicarbazone complexes by studying their structure-activity relationships to obtain an arene binuclear Ru(II) complex (C5) with significant cytotoxicity and high accumulation in the mitochondria of tumor cells. Subsequently, a C5-AFt nanoparticle (NPs) delivery system was constructed. We found that the C5/C5-AFt NPs effectively inhibited TNBC growth and metastasis with few side effects. The C5-AFt NPs improved the anticancer and targeting abilities of C5 in vivo. Moreover, we confirmed the mechanism by which C5/C5-AFt NPs inhibit tumor growth and metastasis via mitochondrial damage-mediated ferroptosis and activation of the cGAS-STING pathway.

Developing a Rhodium(III) Complex to Reprogram the Tumor Immune and Metabolic Microenvironments: Overcoming Multidrug Resistance and Metastasis in Non-Small Cell Lung Cancer.

To effectively inhibit the growth and metastasis of non-small cell lung cancer (NSCLC) and overcome its multidrug resistance (MDR), we designed and synthesized a series of rhodium (Rh, III) 2-benzoylpyridine thiosemicarbazone complexes. Through studying their structure-activity relationships, we identified the Rh(III) complex (Rh4) with excellent cytotoxicity against multidrug-resistant lung cancer cells (A549/ADR cells). Additionally, we successfully constructed an apoferritin (AFt) nanoparticle (NP) delivery system (AFt-Rh4 NPs). Importantly, AFt-Rh4 NPs not only exhibited excellent antitumor and antimetastatic capabilities against multidrug-resistant NSCLC in vivo but also demonstrated enhanced targeting ability and reduced systemic toxicity and adverse effects. Furthermore, we confirmed and elucidated the mechanisms by which Rh4/AFt-Rh4 NPs inhibit tumor metastasis and reverse MDR in NSCLC. This was achieved by reprogramming the immune and metabolic tumor microenvironments through induction of immunogenic cell death and inhibition of dual-energy metabolism.

Rational Design of a Hetero-multinuclear Gadolinium(III)-Copper(II) Complex: Integrating Magnetic Resonance Imaging, Photoacoustic Imaging, Mild Photothermal Therapy, Chemotherapy and Immunotherapy of Cancer.

For more accurate diagnosis and effective treatment of cancer, we proposed to develop a hetero-multinuclear metal complex based on the property of apoferritin (AFt) for targeting tumor theranostics by integrating dual-modality imaging diagnosis and multimodality therapy. To this end, we rational designed and synthesized a trinuclear Gd(III)-Cu(II) thiosemicarbazone complex (Gd-2Cu) and then constructed a Gd-2Cu@AFt nanoparticle (NP) delivery system. Gd-2Cu/Gd-2Cu@AFt NPs not only had significant T1-weighted magnetic resonance imaging and photoacoustic imaging of the tumor but also effectively inhibited tumor growth through a combination of mild photothermal therapy, chemotherapy, and immunotherapy. Gd-2Cu@AFt NPs optimized the behavior of imaging diagnosis and therapy of Gd-2Cu, improved its targeting ability, and reduced the side effects in vivo. Besides, we revealed and clarified the anticancer mechanism of Gd-2Cu: interrupting energy metabolism of the tumor cell, inducing apoptosis of the tumor cell, and activating a systemic immune response by inducing immunogenic cell death of cancer cells.

Photoelectrochemical quenching-recovery biosensor based on NSCQDs/Fe2O3@Bi2S3 for the detection of trypsin

BackgroundThe content of trypsin will change when pancreatic diseases occur, therefore developing a high-performance method for trypsin detection is of great significance for guiding patients on medication plans and improving their prognosis. Photoelectrochemical (PEC) analysis techniques have emerged as a solution to apply for bioassays. ResultsHerein, the Fe2O3@Bi2S3 and Nitrogen and sulfur co-doped carbon quantum dots (NSCQDs) were successfully synthesized by a hydrothermal method. Subsequently, NSCQDs/Fe2O3@Bi2S3 with a photocurrent amplification effect covered on fluorine-doped tin oxide (FTO) electrode as the substrate material and apoferritin (APO) as a bio-recognition element to quench the photocurrent of the substrate material which can be excited with light. Due to the decomposition specifically between APO and trypsin, the photocurrent response increased. The linear range for trypsin detection showed satisfied results from 2 to 1000 ng mL−1 under optimal conditions, with a detection limit of 0.42 ng mL−1 and a recovery rate of 97.41 %–103.02 %, enabling efficient quantitative analysis of trypsin. SignificanceIn this experiment, a PEC biosensor with simple operation, low detection limit, excellent selectivity and strong stability was successfully prepared, enabling quantitative analysis of trypsin in human serum samples through the quenching-recovery mechanism. It holds great significance for diagnosis and serves as a practical method for the detection of trypsin in the future.

Encapsulation of copper phenanthroline within horse spleen apoferritin: characterisation, cytotoxic activity and ability to retain temozolomide.

Protein capsules are promising drug delivery vehicles for cancer research therapies. Apoferritin (AFt) is a self-assembling 12 nm diameter hollow nanocage with many desirable features for drug delivery, however, control of drug retention inside the protein cage remains challenging. Here we report the encapsulation of copper(ii)-1,10-phenanthroline (Cu(phen)) within the horse spleen AFt (HSAFt) nanocage, by diffusion of the metal through the pores between the protein subunits. Transmission electron microscopy revealed the formation of organised copper adducts inside HSAFt, without affecting protein integrity. These structures proved stable during storage (>4 months at -20 °C). Exposure to physiologically relevant conditions (37 °C) showed some selectivity in cargo release after 24 h at pH 5.5, relevant to the internalisation of AFt within the endosome (60% release), compared to pH 7.4, relevant to the bloodstream (40% release). Co-encapsulation of temozolomide, a prodrug used to treat glioblastoma multiforme, and Cu(phen) enabled entrapment of an average of 339 TMZ molecules per cage. In vitro results from MTT and clonogenic assays identified cytotoxic activity of the Cu(phen), HSAFt-Cu(phen) and HSAFt-Cu(phen)-TMZ adducts against colorectal cancer cells (HCT-116) and glioblastoma cells (U373V, U373M). However, the presence of the metal also contributed to more potent activity toward healthy MRC5 fibroblasts, a result that requires further investigation to assess the clinical viability of this system.

Developing a Gadolinium(III) Compound Based on Apoferritin for Targeted Magnetic Resonance Imaging and Dual-Modal Therapy of Cancer.

To integrate targeted diagnosis and treatment of cancer, we proposed to develop a gadolinium (Gd) agent based on the properties of apoferritin (AFt). To this end, we not only optimized a series of Gd(III) 8-hydroxyquinoline-2-carboxaldehyde-thiosemicarbazone compounds to obtain a Gd(III) compound (C4) with remarkable T1-weighted magnetic resonance imaging (MRI) performance and cytotoxicity to cancer cells in vitro but also constructed an AFt-C4 nanoparticle (NP) delivery system. Importantly, AFt-C4 NPs improved the targeting ability of C4 in vivo and showed enhanced MRI performance and tumor growth inhibition ratio relative to C4 alone. Furthermore, we confirmed that C4 and AFt-C4 NPs inhibited tumor growth through apoptosis, ferroptosis, and ferroptosis-induced immune response.

A Dual Function of Ferritin (Animal and Plant): Its Holo Form for Iron Supplementation and Apo Form for Delivery Systems.

Ferritins represent a class of iron storage proteins with detoxification functions. The importance of these proteins is reflected by their wide distribution throughout the animal and plant kingdoms. Ferritin has two forms: holo and apo. Holo ferritin can act as an efficient and safe factor for iron supplementation, whereas apo ferritin is able to serve as a promising delivery nanovehicle for nutrients and bioactive compounds. So far, the dual functions of ferritins from animal and plant sources have been extensively studied in several fields, such as food, nutrition, medicine, and materials. This review outlines the structure of animal and plant ferritin, the iron supplementation function of holo ferritin, and the delivery function of apo ferritin. Recent advances in iron supplementation and nutrient encapsulation and delivery are highlighted. Finally, the current challenges and future developments for multifunctional applications of ferritins are discussed. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 14 is March 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Biomimetic-compartmented nanoprobe for in-situ imaging of iron storage and release from ferritin in cells

Ferritin plays an important role in regulating the homeostasis of iron in cells by storing/releasing iron. Current methods usually explored the determination of iron content, but in-situ imaging of the iron storage/release from ferritin in cells cannot be achieved. Hence, an engineered self-assembled biomimetic-compartmented nanoprobe (APO@CDs) has been constructed. The protein shell of APO (apoferritin) acted as ion channel module to control iron ions entering/exiting ferritin cavity; the inner core of CDs (carbon dots) acted as signal module for iron ions response. Compared with CDs, the response sensitivity and specificity to iron ions (Fe3+) have been improved by using APO@CDs, and the cytotoxicity was significantly reduced. Additionally, compared with cells containing APO@CDs alone, the normalized fluorescence gray value of Fe3+-treated cells was significantly decreased (0.275), indicating that Fe3+ has effectively entered the ferritin. Furtherly, that of Fe3+-treated cells incubated with deferoxamine (DFO) was significantly enhanced (0.712), showing that Fe3+ was released from ferritin under the mediation of DFO. The results demonstrate that APO@CDs can be successfully applied to in-situ imaging of iron storage/release from ferritin in cells, providing a potential platform for the in-situ dynamic study of the iron storage/release in biomedical field.

Apoferritin-Encapsulated Jerantinine A for Transferrin Receptor Targeting and Enhanced Selectivity in Breast Cancer Therapy.

The O-acetyl (or acetate) derivative of the Aspidosperma alkaloid Jerantinine A (JAa) elicits anti-tumor activity against cancer cell lines including mammary carcinoma cell lines irrespective of receptor status (0.14 < GI50 < 0.38 μM), targeting microtubule dynamics. By exploiting breast cancer cells’ upregulated transferrin receptor 1 (TfR1) expression and apoferritin (AFt) recognition, we sought to develop an AFt JAa-delivery vehicle to enhance tumor-targeting and reduce systemic toxicity. Optimizing pH-mediated reassembly, ∼120 JAa molecules were entrapped within AFt. Western blot and flow cytometry demonstrate TfR1 expression in cancer cells. Enhanced internalization of 5-carboxyfluorescein-conjugated human AFt in SKBR3 and MDA-MB-231 cancer cells is observed compared to MRC5 fibroblasts. Accordingly, AFt–JAa delivers significantly greater intracellular JAa levels to SKBR3 and MDA-MB-231 cells than naked JAa (0.2 μM) treatment alone. Compared to naked JAa (0.2 μM), AFt–JAa achieves enhanced growth inhibition (2.5–14-fold; <0.02 μM < GI50 < 0.15 μM) in breast cancer cells; AFt–JAa treatment results in significantly reduced clonal survival, more profound cell cycle perturbation including G2/M arrest, greater reduction in cell numbers, and increased apoptosis compared to the naked agent (p < 0.01). Decreased PLK1 and Mcl-1 expression, together with the appearance of cleaved poly (ADP-ribose)-polymerase, corroborate the augmented potency of AFt–JAa. Hence, we demonstrate that AFt represents a biocompatible vehicle for targeted delivery of JAa, offering potential to minimize toxicity and enhance JAa activity in TfR1-expressing tumors.

Toward understanding the kinetics of disassembly of ferritins of varying origin and subunit composition

Understanding the reversible reassembly properties of ferritins (FRTs) is crucial for enabling their applicability in nanomedicine. These properties include drug loading capabilities and also subsequent payload release in desired site-of-action. Thus, the presented study is focused on understanding the disassembly of recombinantly produced FRTs of varying origin and subunit composition, i.e. equine FRT composed of 22 L- and 2 H-subunits (EcaLH) or 24 L-subunits (EcaL), human FRT composed of 24 H-subunits (HsaH) and archaeal Pyrococcus furiosus FRT (Pfu). Disassembly was distinctly influenced by pH and ionic strength. Except for Pfu, the disassembly kinetics in acidic pH is rapid upon reaching an innate threshold, reaching the final state within minutes. Disassembly kinetics in basic pH is slower. Pfu is partially disassembled within the entire pH range. While equine FRT disassembles into free subunits, HsaH disassembles into subunit clusters. EcaL and Pfu form large aggregates during disassembly in mildly acidic pH, although basic pH causes partial disassembly without aggregation, suggesting usability for basic pH-triggered drug loading. We show that in human serum/plasma, FRTs readily form protein corona, hampering their uptake. Interestingly, we found out that archaeal Pfu likely exhibits similar receptor affinity as mammalian FRTs. Further, in vivo toxicity and biodistribution study of a single dose of FRTs demonstrated very low toxicity of FRTs and their preferential liver/kidney bioaccumulation.

Roles of homopolymeric apoferritin in alleviating alcohol-induced liver injury

Alcohol abuse induced liver damage are closely related to oxidative stress, several efforts have been made to quench free radicals produced in the liver. Heteropolymeric soybean seed ferritin has been proved to protect DNA from oxidative damage. However, the roles of homopolymeric apoferritin in quenching free radicals have been neglected so far. In order to improve the ferroxidase activity of ferritin, we have prepared apo ferritin by removing iron core from the cavity. In this study, the roles of apo shrimp ferritin (Marsupenaeus japonicus ferritin, MjFer) and human H chain ferritin (HuHF) in attenuating the hydroxyl radicals in vitro and in vivo has been investigated. Results showed that MjFer was able to quench the free radicals produced by iron oxidation more efficiently than HuHF in vitro. Animal studies using a mouse model of alcohol-induced acute liver injury revealed that MjFer is much more efficacious than HuHF in alleviating the liver injury, by attenuating oxidative stress and regulating Nrf2/HO1 expression. Accordingly, the higher activity of MjFer may be attributed to its faster iron oxidative rate than HuHF, which may help improve the intestinal integrity, and reduce abnormal iron absorption. As expected, iron contents in the liver of MjFer and HuHF group are much lower than that of model group, further alleviating the liver damage. These findings suggest that apoferritin may be a promising candidate for alcohol-induced liver injury.

New insight into the structural changes of apoferritin pores in the process of doxorubicin loading at an acidic pH: Molecular dynamics simulations

Apoferritin (APO-Fr) is one of the most investigated proteins proposed as an advanced structure for drug delivery systems. Herein, molecular dynamics simulation was employed to compare the opening of 3-fold and 4-fold pores in APO-Fr during the partial disassembly process at an acidic pH. We showed that more hydrophilic residues in the surface of 3-fold pores compared to 4-fold pores facilitate increased flexibility and a higher tendency to open. In particular, dissociation is induced by the presence of Doxorubicin (DOX) close to 3-fold pores. Our simulations showed loaded DOXs on the APO-Fr surface were mainly involved in the hydrogen bond interactions with the hydrophilic residues, suggesting the difficulty of hydrophobic drugs loading in APO-Fr with the partial disassembly process. However, π-π interactions as well as hydrogen bonds between protein and DOXs were mediated by the basic and acidic amino acids such as HIP128, GLU17, and LYS143 at the open pores, providing penetration of DOXs into the H-Apo-Fr. We conclude that increased drug encapsulations and loading capacity of hydrophobic drugs into the cavity of APO-Fr are feasible by further disassembly of openings to access the internal hydrophobic portions of the protein.

Two ferritins from Dermanyssus gallinae: characterization and in vivo assessment as protective antigens.

The poultry red mite, Dermanyssus gallinae is recognized worldwide as the most important bloodsucking ectoparasite in layer and breeder flocks. In bloodsucking ectoparasites, ferritins (FERs), the iron-storage proteins, play a pivotal role in dealing with the challenge of large amounts of released iron during the digestion of blood meal. However, no information is available concerning FERs of D.gallinae. The aim of the present study was to investigate the characteristics, functions and the vaccine efficacy of FERs in D.gallinae. Two heavy-chain FERs of D.gallinae were identified and characterized. Phylogenetic analysis indicated that Dg-FER1 may be a secretory FER and Dg-FER2 an intracellular one. RNAi results demonstrated that Dg-fers play key roles in mite survival, successful reproduction and blood digestion. Immunization with rDg-FER1 or rDg-FER2 successfully induced chickens to produce high levels of antigen-specific IgY, resulting in a significant increase in mite mortality (by 58.67% on Day 5) and decreases in oviposition (by 42.15%) and fecundity (by 68.97%) in the rDg-FER1 group, and a 13.73% increase in mite mortality and a 20.89% decrease in fecundity in the rDg-FER1 group. The overall immunization efficacy of rDg-FER1 was 93.51%. Two Dg-FERs are crucial to the survival, reproduction and blood digestion of D.gallinae. This study has provided preliminary evidence demonstrating the potential of rDg-FER1 as a vaccine antigen for D.gallinae. © 2021 Society of Chemical Industry.

Chemosensitization of Temozolomide-Resistant Pediatric Diffuse Midline Glioma Using Potent Nanoencapsulated Forms of a N(3)-Propargyl Analogue.

The lack of clinical response to the alkylating agent temozolomide (TMZ) in pediatric diffuse midline/intrinsic pontine glioma (DIPG) has been associated with O6-methylguanine-DNA-methyltransferase (MGMT) expression and mismatch repair deficiency. Hence, a potent N(3)-propargyl analogue (N3P) was derived, which not only evades MGMT but also remains effective in mismatch repair deficient cells. Due to the poor pharmacokinetic profile of N3P (t1/2 < 1 h) and to bypass the blood-brain barrier, we proposed convection enhanced delivery (CED) as a method of administration to decrease dose and systemic toxicity. Moreover, to enhance N3P solubility, stability, and sustained distribution in vivo, either it was incorporated into an apoferritin (AFt) nanocage or its sulfobutyl ether β-cyclodextrin complex was loaded into nanoliposomes (Lip). The resultant AFt-N3P and Lip-N3P nanoparticles (NPs) had hydrodynamic diameters of 14 vs 93 nm, icosahedral vs spherical morphology, negative surface charge (-17 vs -34 mV), and encapsulating ∼630 vs ∼21000 N3P molecules per NP, respectively. Both NPs showed a sustained release profile and instant uptake within 1 h incubation in vitro. In comparison to the naked drug, N3P NPs demonstrated stronger anticancer efficacy against 2D TMZ-resistant DIPG cell cultures [IC50 = 14.6 (Lip-N3P) vs 32.8 μM (N3P); DIPG-IV) and (IC50 = 101.8 (AFt-N3P) vs 111.9 μM (N3P); DIPG-VI)]. Likewise, both N3P-NPs significantly (P < 0.01) inhibited 3D spheroid growth compared to the native N3P in MGMT+ DIPG-VI (100 μM) and mismatch repair deficient DIPG-XIX (50 μM) cultures. Interestingly, the potency of TMZ was remarkably enhanced when encapsulated in AFt NPs against DIPG-IV, -VI, and -XIX spheroid cultures. Dynamic PET scans of CED-administered zirconium-89 (89Zr)-labeled AFt-NPs in rats also demonstrated substantial enhancement over free 89Zr radionuclide in terms of localized distribution kinetics and retention within the brain parenchyma. Overall, both NP formulations of N3P represent promising approaches for treatment of TMZ-resistant DIPG and merit the next phase of preclinical evaluation.

A promising dual-drug targeted delivery system in cancer therapy: nanocomplexes of folate–apoferritin-conjugated cationic solid lipid nanoparticles

Various nano-sized protein and lipid complexes are being investigated as drug delivery systems. The encapsulation of more than one drug in a single nanocomplex carrier could enhance the therapeutic potency and afford synergistic therapeutic effects. In this study, we developed a novel protein-lipid nanocomplex as a controlled drug delivery system for two important cancer drugs, doxorubicin (DOX) and mitoxantrone (MTO). Apoferritin (AFr) functionalized with folic acid (FA) was used to encapsulate DOX to create the targeted protein nanocomplexes (TPNs). The second drug, MTO, was loaded into the cationic solid lipid nanoparticles (cSLN) to form the liposomal drug nanocomplex particles (MTO-cSLNs). Two complexes were then assembled by tight coupling through ionic interactions to obtain the final drug delivery system, the dual-targeted protein-lipid nanocomplexes (DTPLNs). UV-Vis and fluorescence spectroscopy were used for structural characterization of TPNs and DTPLNs. Transmission electron microscopy (TEM) was used for comprehensive analysis of the final DTPLNs. We confirmed that the DTPLNs display desired time-dependent and pH-dependent drug release behaviors. We also demonstrated the improved anti-cancer efficacy of DOX and MTO in their encapsulated DTPLNs as compared to their free forms. Our results provide promising prospects for the application of the DTPLNs as efficient drug delivery systems.

Apoferritin nanoparticle based dual-antigen influenza conjugate vaccine with potential cross-protective efficacy against heterosubtypic influenza virus

Ferritin nanoparticles with self-assembling properties have been widely explored as vaccine carrier by displaying foreign antigens through genetic fusion strategy. In the present work, an apoferritin (AFt) nanoparticle was tested as influenza vaccine carrier by chemically conjugating a matrix protein 2 ectodomain (M2e) antigen peptide or/and the full-length hemagglutinin (HA) antigen on the outer surface of the AFt, with heterobifunctional sSMCC or SM(PEG)24 containing PEG chain as linkers. To each AFt nanoparticle, about 30–32 M2e or 1.8 HA antigen could be coupled. The AFt-(PEG)24-M2e, in which the M2e was coupled through SM(PEG)24 containing PEG chain, conferred higher protective efficacy in immunized mice than AFt-M2e did, but was less effective than AFt-(PEG)24-HA. When both M2e and HA were coupled, the synthesized dual-antigen vaccine candidate AFt-(PEG)24-M2e/HA elicited high level of M2e and HA antigen-specific antibodies and conferred 100% protection against lethal infection of homologous PR8 H1N1 virus strain and 70% protection against a heterologous A/FM/1/47 (FM1, H1N1) strain, which was more effective than the M2e or HA single antigen vaccine candidates. The potential cross-protective effect of the dual-antigen vaccine was further demonstrated by significant specific hemagglutination inhibition (HAI) titers in serum of the immunized mice against three other heterologous viral strains including A/Singapore/GP1908/2015 (IVR-180) H1N1, A/Anhui/1/2005 H5N1, and A/Hong Kong H3N2.

Arsenoplatin-Ferritin Nanocage: Structure and Cytotoxicity.

Arsenoplatin-1 (AP-1), the prototype of a novel class of metallodrugs containing a PtAs(OH)2 core, was encapsulated within the apoferritin (AFt) nanocage. UV-Vis absorption spectroscopy and inductively coupled plasma-atomic emission spectroscopy measurements confirmed metallodrug encapsulation and allowed us to determine the average amount of AP-1 trapped inside the cage. The X-ray structure of AP-1-encapsulated AFt was solved at 1.50 Å. Diffraction data revealed that an AP-1 fragment coordinates the side chain of a His residue. The biological activity of AP-1-loaded AFt was comparatively tested on a few representative cancer and non-cancer cell lines. Even though the presence of the cage reduces the overall cytotoxicity of AP-1, it improves its selectivity towards cancer cells.

Cancer-Targeted Controlled Delivery of Chemotherapeutic Anthracycline Derivatives Using Apoferritin Nanocage Carriers

The interactions of chemotherapeutic drugs with nanocage protein apoferritin (APO) are the key features in the effective encapsulation and release of highly toxic drugs in APO-based controlled drug delivery systems. The encapsulation enables mitigating the drugs’ side effects, collateral damage to healthy cells, and adverse immune reactions. Herein, the interactions of anthracycline drugs with APO were studied to assess the effect of drug lipophilicity on their encapsulation excess n and in vitro activity. Anthracycline drugs, including doxorubicin (DOX), epirubicin (EPI), daunorubicin (DAU), and idarubicin (IDA), with lipophilicity P from 0.8 to 15, were investigated. We have found that in addition to hydrogen-bonded supramolecular ensemble formation with n = 24, there are two other competing contributions that enable increasing n under strong polar interactions (APO(DOX)) or under strong hydrophobic interactions (APO(IDA) of the highest efficacy). The encapsulation/release processes were investigated using UV-Vis, fluorescence, circular dichroism, and FTIR spectroscopies. The in vitro cytotoxicity/growth inhibition tests and flow cytometry corroborate high apoptotic activity of APO(drugs) against targeted MDA-MB-231 adenocarcinoma and HeLa cells, and low activity against healthy MCF10A cells, demonstrating targeting ability of nanodrugs. A model for molecular interactions between anthracyclines and APO nanocarriers was developed, and the relationships derived compared with experimental results.