Improved therapeutic activity of HER2 Affibody-targeted cisplatin liposomes in HER2-expressing breast tumor models

Functionalized liposomes for targeted breast cancer drug delivery

Despite the exceptional progress in breast cancer pathogenesis, prognosis, diagnosis, and treatment strategies, it remains a prominent cause of female mortality worldwide. Additionally, although chemotherapies are effective, they are associated with critical limitations, most notably their lack of specificity resulting in systemic toxicity and the eventual development of multi-drug resistance (MDR) cancer cells. Liposomes have proven to be an invaluable drug delivery system but of the multitudes of liposomal systems developed every year only a few have been approved for clinical use, none of which employ active targeting. In this review, we summarize the most recent strategies in development for actively targeted liposomal drug delivery systems for surface, transmembrane and internal cell receptors, enzymes, direct cell targeting and dual-targeting of breast cancer and breast cancer-associated cells, e.g., cancer stem cells, cells associated with the tumor microenvironment, etc.

Codelivery of TRAIL and Mitomycin C via Liposomes Shows Improved Antitumor Effect on TRAIL-Resistant Tumors

Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) constitutes a promising antitumor drug, tumor resistance to TRAIL has become a major obstacle in its clinical application. Mitomycin C (MMC) is an effective TRAIL-resistant tumor sensitizer, which indicates a potential utility of combination therapy. However, the efficacy of this combination therapy is limited owing to its short half-life and the cumulative toxicity of MMC. To address these issues, we successfully developed a multifunctional liposome (MTLPs) with human TRAIL protein on the surface and MMC encapsulated in the internal aqueous phase to codeliver TRAIL and MMC. MTLPs are uniform spherical particles that exhibit efficient cellular uptake by HT-29 TRAIL-resistant tumor cells, thereby inducing a stronger killing effect compared with control groups. In vivo assays revealed that MTLPs efficiently accumulated in tumors and safely achieved 97.8% tumor suppression via the synergistic effect of TRAIL and MMC in an HT-29 tumor xenograft model while ensuring biosafety. These results suggest that the liposomal codelivery of TRAIL and MMC provides a novel approach to overcome TRAIL-resistant tumors.

Challenges and emerging strategies for next generation liposomal based drug delivery: An account of the breast cancer conundrum

The global cancer burden is witnessing an upsurge with breast cancer surpassing other cancers worldwide. Furthermore, an escalation in the breast cancer caseload is also expected in the coming years. The conventional therapeutic regimens practiced routinely are associated with many drawbacks to which nanotechnological interventions offer a great advantage. But how eminent could liposomes and their advantages be in superseding these existing therapeutic modalities? A solution is reflected in this review that draws attention to a decade-long journey embarked upon by researchers in this wake. This text is a comprehensive discussion of liposomes, the front runners of the drug delivery systems, and their active and passive targeting approaches for breast cancer management. Active targeting has been studied over the decade by many receptors overexpressed on the breast cancer cells and passive targeting with many drug combinations. The results converge on the fact that the actively targeted formulations exhibit a superior efficacy over their non-targeted counterparts and the all liposomal formulations are efficacious over the free drugs. This undoubtedly underlines the dominion of liposomal formulations over conventional chemotherapy. These investigations have led to the development of different liposomal formulations with active and passive targeting capacities that could be explored in depth. Acknowledging and getting a deeper insight into the liposomal evolution through time also unveiled many imperfections and unchartered territories that can be explored to deliver dexterous liposomal formulations against breast cancer and more in the clinical trial pipeline.

Amino acid coordination complex mediates cisplatin entrapment within PEGylated liposome: An implication in colorectal cancer therapy

Cis-Diaminedichloroplatinum (cisplatin, CDDP) remained among the most widely used anti-cancer agents; however, management of the dose-limiting side effects is still a great hurdle to its therapeutic potential. In the framework of this investigation, novel approach was developed for CDDP encasement within liposome based on the formation of a coordination bond between the platinum (II) atom and a carboxylic group in aspartic acid (AA) and glutamic acid (GA). We have also compared two methods of preparation based on equilibration and conventional lipid film hydration. For this, first FTIR spectra of the conjugates confirmed coordination bond between Pt and the carboxylate moieties. The PEGylated liposomes composed of HSPC, cholesterol and DPPG had a size of 134 to 197 nm and negative zeta potential (-14.20 to -20.90 mv). Cytotoxicity study revealed IC₅₀ values of <7 µg/ml for liposomes. In vivo plasma retention following iv administration indicated the potential of liposome in maintaining cisplatin levels within the circulation, while free cisplatin and cisplatin conjugates were promptly eliminated. Anti-tumor efficacy studies following iv injections at 3 mg/kg cisplatin weekly for three weeks in C26 tumor bearing BALB/c mice demonstrated the potential of the cisplatin liposomes in tumor growth inhibition. Pt-complexes were not as effective as liposomal formulations showing the crucial role of liposomes in maintaining cisplatin levels within blood circulation. Overall, the developed cisplatin liposome seems to be a promising therapeutic approach for targeting solid tumors.

Functionalization of Nanoparticulate Drug Delivery Systems and Its Influence in Cancer Therapy

Research into the application of nanocarriers in the delivery of cancer-fighting drugs has been a promising research area for decades. On the other hand, their cytotoxic effects on cells, low uptake efficiency, and therapeutic resistance have limited their therapeutic use. However, the urgency of pressing healthcare needs has resulted in the functionalization of nanoparticles' (NPs) physicochemical properties to improve clinical outcomes of new, old, and repurposed drugs. This article reviews recent research on methods for targeting functionalized nanoparticles to the tumor microenvironment (TME). Additionally, the use of relevant engineering techniques for surface functionalization of nanocarriers (liposomes, dendrimers, and mesoporous silica) and their critical roles in overcoming the current limitations in cancer therapy-targeting ligands used for targeted delivery, stimuli strategies, and multifunctional nanoparticles-were all reviewed. The limitations and future perspectives of functionalized nanoparticles were also finally discussed. Using relevant keywords, published scientific literature from all credible sources was retrieved. A quick search of the literature yielded almost 400 publications. The subject matter of this review was addressed adequately using an inclusion/exclusion criterion. The content of this review provides a reasonable basis for further studies to fully exploit the potential of these nanoparticles in cancer therapy.

Artificial Scaffold Polypeptides As an Efficient Tool for the Targeted Delivery of Nanostructures In Vitro and In Vivo

The use of traditional tools for the targeted delivery of nanostructures, such as antibodies, transferrin, lectins, or aptamers, often leads to an entire range of undesirable effects. The large size of antibodies often does not allow one to reach the required number of molecules on the surface of nanostructures during modification, and the constant domains of heavy chains, due to their effector functions, can induce phagocytosis. In the recent two decades, targeted polypeptide scaffold molecules of a non-immunoglobulin nature, antibody mimetics, have emerged as much more effective targeting tools. They are small in size (3–20 kDa), possess high affinity (from subnano- to femtomolar binding constants), low immunogenicity, and exceptional thermodynamic stability. These molecules can be effectively produced in bacterial cells, and, using genetic engineering manipulations, it is possible to create multispecific fusion proteins for the targeting of nanoparticles to cells with a given molecular portrait, which makes scaffold polypeptides an optimal tool for theranostics.

Nanocarriers Call the Last Shot in the Treatment of Brain Cancers

Our brain is protected by physio-biological barriers. The blood–brain barrier (BBB) main mechanism of protection relates to the abundance of tight junctions (TJs) and efflux pumps. Although BBB is crucial for healthy brain protection against toxins, it also leads to failure in a devastating disease like brain cancer. Recently, nanocarriers have been shown to pass through the BBB and improve patients’ survival rates, thus becoming promising treatment strategies. Among nanocarriers, inorganic nanocarriers, solid lipid nanoparticles, liposomes, polymers, micelles, and dendrimers have reached clinical trials after delivering promising results in preclinical investigations. The size of these nanocarriers is between 10 and 1000 nm and is modified by surface attachment of proteins, peptides, antibodies, or surfactants. Multiple research groups have reported transcellular entrance as the main mechanism allowing for these nanocarriers to cross BBB. Transport proteins and transcellular lipophilic pathways exist in BBB for small and lipophilic molecules. Nanocarriers cannot enter via the paracellular route, which is limited to water-soluble agents due to the TJs and their small pore size. There are currently several nanocarriers in clinical trials for the treatment of brain cancer. This article reviews challenges as well as fitting attributes of nanocarriers for brain tumor treatment in preclinical and clinical studies.

Combinatorial in silico and in vivo evaluation of immune response elicitation by the affibody ZHER2

Due to the high affinity for binding to target molecules and also other unique attributes, affibodies have a great potential to be used in immunotherapeutic and diagnostic approaches. However, the possibility of undesirable immune response is still a great concern. In the current study, we investigated the possible antigenicity, allergenicity and cytotoxicity of the HER2-targeting affibody Z_HER2. The binding affinity of potential epitopes of the affibody to murine major histocompatibility complex (MHC) molecules was investigated by immunoinformatics tools and docking approaches. The possible interaction of Z_HER2 with human leukocyte antigens HLA-DP, HLA-DM, HLA-DQ and HLA-DR was also studied by protein-protein docking. Additionally, the synthesized affibody gene was expressed and the protein was purified for boosted immunization of Balb/c mice. Induced secretion of IFN-γ, IL-2, IL-4 and IL-10, and total serum IgG were assessed in the immunized mice. Furthermore, MTT cell viability test was performed to evaluate the cytotoxicity of Z_HER2 in splenocytes of the treated mice. In silico analyses showed the possible induction of the immune response by Z_HER2. While the affibody could elicit the secretion of cellular immune cytokines, it could not induce a significant humoral response in the treated mice and did not show any cytotoxic effects on the exposed splenocytes. These findings explain the practicability of Z_HER2 for therapeutic and in vivo diagnostic usages, though its ubiquitous application may need more studies.

Coupling EGFR-Antagonistic Affibody Enhanced Therapeutic Effects of Cisplatin Liposomes in EGFR-expressing Tumor Models

Epidermal growth factor receptor (EGFR) is an efficient target for cancer therapy. In this study, a high-affinity EGFR-antagonistic affibody (Z_EGFR) molecule coupled with cisplatin-loaded PEGylated liposomes (LS-DDP) was applied to actively target EGFR⁺ A431 tumor cells in vitro and in vivo. The LS-DDP coupled with Z_EGFR (AS-DDP) had an average size of 140.01 ± 0.84 nm, low polydispersity, a zeta potential of -13.40 ± 0.8 mV, an acceptable encapsulation efficiency of 17.30 ± 1.35%, and released cisplatin in a slow-controlled manner. In vitro, AS-DDP demonstrated a higher amount of platinum intracellular uptake by A431 cells than LS-DDP. The IC50 value of AS-DDP (9.02 ± 1.55 μg/ml) was much lower than that of LS-DDP (16.44 ± 0.87 μg/ml), indicating that the anti-tumor effects of AS-DDP were remarkable due to the modification of Z_EGFR. In vivo, the concentration of AS-DDP in the tumor site increased more than 1.76-fold, while an increase in apoptotic cells at 48 h compared to the LS-DDP was also observed, illustrating that AS-DDP possessed excellent tumor-targeting efficiency. As a result, the targeted nano-liposomes achieved greater tumor suppression. Therefore, selective targeting of LS-DDP coupled with Z_EGFR enhanced the anti-tumor effects and appeared to be a promising strategy for the treatment of EGFR⁺ tumors.

Improvement of Targeted Chemotherapy of HER2-positive Ovarian Malignant Cell Line by ZHER2-Idarubicin Conjugate: An in vitro Study

Background & Objective:

Overexpression of human epidermal growth factor receptor 2 (HER2) causes cell transformation and development of various types of malignancies. Idarubicin is an effective anti-neoplastic drug but its specific delivery to the targeted cells is still a great challenge. Affibody as a cost-effective peptide molecule with low molecular weight has a high affinity for HER2 receptors. Breast and ovarian cancers as wide speared types of malignancies are associated with high expression of HER2. In the current study, we assessed the cytotoxic effects of idarubicin-Z_HER2 affibody conjugate on the positive-HER2 cancer cell lines.

Methods:

The cytotoxic effects of constructed idarubicin-Z_HER2 affibody conjugate on the SK-BR-3, SK-OV-3, and MCF-7 cells with various levels of HER2 expression were evaluated by MTT assay following 48 hours of incubation.

Results:

Idarubicin showed a potent and dose-dependent cytotoxic effect against all treated cell lines while the SK-OV-3 cells were significantly more sensitive. The dimeric form of the Z_HER2 affibody molecule showed a mild effect on the cell viability of all treated cells at its optimum concentration. The constructed Idarubicin-Z_HER2 affibody conjugate decreased the viability of SK-OV-3 cells at its optimal concentration, more efficiently and specifically than other treated cells.

Conclusion:

The Z_HER2-affibody conjugate of idarubicin has a more specific cytotoxic effect compared with idarubicin alone against HER2-overexpressing ovarian cancerous cells. It appears the Z_HER2-affibody conjugate of idarubicin has great potential to be implicated as an innovative anti-cancer agent in future clinical trials in patients with HER2-overexpressing ovarian cancer.

Relevant Physicochemical Methods to Functionalize, Purify, and Characterize Surface-Decorated Lipid-Based Nanocarriers

Surface functionalization of lipid-based nanocarriers (LBNCs) with targeting ligands has attracted huge interest in the field of nanomedicines for their ability to overcome some physiological barriers and their potential to deliver an active molecule to a specific target without causing damage to healthy tissues. The principal objective of this review is to summarize the present knowledge on LBNC decoration used for biomedical applications, with an emphasis on the ligands used, the functionalization approaches, and the purification methods after ligand corona formation. The most potent experimental techniques for the LBNC surface characterization are described. The potential of promising methods such as nuclear magnetic resonance spectroscopy and isothermal titration calorimetry to characterize ligand surface corona is also outlined.

Specific targeting of HER2-positive human breast carcinoma SK-BR-3 cells by amygdaline-ZHER2 affibody conjugate

Amygdalin induces apoptotic death in several carcinoma cells. Affibody is an engineered protein with a high affinity for human epidermal receptor 2 (HER2). We assessed the cytotoxic effects of the amygdalin-Z_HER2 affibody conjugate on two breast carcinoma cell lines. The Z_HER2 affibody gene was synthesized and transferred into E. coli BL21 as an expression host. After purification, the Z_HER2 affibody was conjugated to amygdalin. The cytotoxic effects of amygdalin and its Z_HER2 affibody conjugate on the SK-BR-3, with overexpression of HER2, and MCF-7 cells were evaluated by MTT assay. The effects of amygdalin and its conjugate on apoptotic death and expression of pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins were measured. Amygdalin individually showed a potent cytotoxic effect against both MCF-7 (IC₅₀ = 14.2 mg ml^-1) and SK-BR-3 cells (IC₅₀ = 13.7 mg ml^-1). However, the amygdalin-Z_HER2 affibody conjugate had a more cytotoxic effect on SK-BR-3 (IC₅₀ = 8.27 mg ml^-1) than MCF-7 cells (IC₅₀ = 19.8 mg ml^-1). Amygdalin had a significant apoptotic effect on both cell lines and the effect of its conjugate on SK-BR-3 cells was significantly more potent than MCF-7 cells. Amygdalin increased Bax and decreased Bcl-2 expression in both cell lines. However, the effect of its conjugate on the Bax and Bcl-2 expression in SK-BR-3 was more potent than MCF-7 cells. In conclusion, the amygdalin-Z_HER2 affibody conjugate may be considered as a valuable candidate for specific treatment of breast cancer patients with overexpression of HER2. However, further in vivo studies are required to explain the antitumoral effects of constructed amygdalin-Z_HER2 affibody conjugate.

A Multi-action PtIV Conjugate with Oleate and Cinnamate Ligands Targets Human Epithelial Growth Factor Receptor HER2 in Aggressive Breast Cancer Cells

HER2-positive breast cancer is an aggressive subtype that typically responds poorly to standard chemotherapy. To design an anticancer drug selective for HER2-expressing breast cancer, a Pt^IV prodrug with axial oleate and cinnamate ligands was synthesized. We demonstrate its superior antiproliferative activity in monolayer and 3D spheroid models; the antiproliferative efficiency increases gradually with increasing expression of HER2. The results also suggest that the released Pt^II compound inhibits the proliferation of cancer cells by a DNA-damage-mediated mechanism. Simultaneously, the released oleic and cinnamic acid can effectively inhibit HER2 expression. To our knowledge, this is the first platinum-based complex inhibiting HER2 expression that does not contain protein or peptide. Moreover, this Pt^IV prodrug is capable of overcoming the resistance of cancer stem cells (CSCs), inducing death in both CSCs and differentiated cancer cells. Thus, the results substantiate our design strategy and demonstrate the potential of this approach for the development of new, therapeutically relevant compounds.

Increasing the antitumor efficacy of doxorubicin liposomes with coupling an anti-EGFR affibody in EGFR-expressing tumor models

Epidermal growth factor receptor (EGFR) is overexpressed in a wide range of solid tumors. In this study, we exploited a high-affinity EGFR-antagonistic affibody (Z_EGFR) coupled to a doxorubicin loaded pegylated liposome (LS-Dox) for concurrent passive and active targeting of EGFR⁺ A431 tumor cells in vitro and in vivo. The in vitro studies revealed that the Dox liposomes coupled with Z_EGFR (AS-Dox) showed a higher Dox uptake than LS-Dox in EGFR⁺ A431 cells but not in EGFR^- B16F10 cells, resulting in a selectively enhanced cytotoxicity. In vivo, AS-Dox confirmed its long circulation time and efficient accumulation in tumors. This targeted chemotherapy achieved greater tumor suppression. Further, this low-dose but effective targeted treatment reduced systemic toxicity such as body weight loss and organ injury demonstrated by H&E staining. Thus, selective targeting of LS-Dox coupled with Z_EGFR enhanced antitumor effects and improved systemic safety. These results demonstrated that LS-Dox coupled with Z_EGFR might be developed as a potential tool for therapy of EGFR⁺ tumors.

Conjugated linoleic acid loaded nanostructured lipid carrier as a potential antioxidant nanocarrier for food applications

The encapsulation of fatty acids in nanocarrier systems is a very effective technique in improving their biological efficiency and controlled delivery. Nanostructured lipid carrier (NLC) is a major type of lipid-based nanoparticle. This study is focused on producing nanolipid carrier containing conjugated linoleic acid and fortifying low-fat milk using this nanoparticle. Nanostructured lipid carriers were produced by hot high-shear homogenization containing 1.5% Poloxamer 407, cocoa butter as solid lipid, and conjugated linoleic acid as liquid oil in ratio of 10:1. Results showed that the nanoparticles sized 81 nm with monomodular dispersity and the system was stable at 4 and 22°C for 40 days. Zeta potential and encapsulation efficiency (%EE) were -15.8 mV and 98.2%, respectively. Scanning electron microscopy (SEM) showed that the particles are in spiral form and small size and no significant aggregation was observed because of few changes in the system turbidity after storage time. The result of oxidative stability showed that using Nanostructured lipid carriers system resulted in lower malone dialdehyde production. Conjugated linoleic acid was protected at level of 3.9% of milk fatty acids in Nanostructured lipid carrier formulation during storage time. Based on these findings, Nanostructured lipid carriers system is an appropriate and stable nanocarrier system for delivery of nutraceuticals in foods and can be used in protecting them against oxidation, heating, and other processes in order to fortify foods and beverages.

Affibody-Binding Ligands

While antibodies remain established therapeutic and diagnostic tools, other protein scaffolds are emerging as effective and safer alternatives. Affibodies in particular are a new class of small proteins marketed as bio-analytic reagents. They feature tailorable binding affinity, low immunogenicity, high tissue permeation, and high expression titer in bacterial hosts. This work presents the development of affibody-binding peptides to be utilized as ligands for their purification from bacterial lysates. Affibody-binding candidates were identified by screening a peptide library simultaneously against two model affibodies (anti-immunoglobulin G (IgG) and anti-albumin) with the aim of selecting peptides targeting the conserved domain of affibodies. An ensemble of homologous sequences identified from screening was synthesized on Toyopearl^® resin and evaluated via binding studies to select sequences that afford high product binding and recovery. The affibody-peptide interaction was also evaluated by in silico docking, which corroborated the targeting of the conserved domain. Ligand IGKQRI was validated through purification of an anti-ErbB2 affibody from an Escherichia coli lysate. The values of binding capacity (~5 mg affibody per mL of resin), affinity (K_D ~1 μM), recovery and purity (64-71% and 86-91%), and resin lifetime (100 cycles) demonstrate that IGKQRI can be employed as ligand in affibody purification processes.

Biologicals to direct nanotherapeutics towards HER2-positive breast cancers

HER2-positive breast cancer, an aggressive cancer, is treated with combinations of conventional anticancer drugs viz., cytotoxic drugs, nibs, and mAbs. Major limitations associated with this therapy are patient non-compliance due to the adverse drug reactions and rapid development of resistance by the HER2-positive malignant cells. While the former is addressed by the nano-formulations of the anticancer-drugs to some extent, the latter is still at large. This is because the nanocarriers of the anticancer drugs, by and large, lack the target specificity and selectivity. Thus, nowadays, to overcome these problems, various safe and efficacious biological agents are being used to direct the nanotherapeutics towards the HER2-positive breast cancers. The present review describes the potentials of such biological agents.

Enhanced Efficacy of PEGylated Liposomal Cisplatin: In Vitro and In Vivo Evaluation

This study aims to evaluate the potency of cisplatin (Cispt)-loaded liposome (LCispt) and PEGylated liposome (PLCispt) as therapeutic nanoformulations in the treatment of bladder cancer (BC). Cispt was loaded into liposomes using reverse-phase evaporation method, and the formulations were characterized using dynamic light scattering, scanning electron microscopy, dialysis membrane, and Fourier-transform infrared spectroscopy (FTIR) methods. The results showed that the particles were formed in spherical monodispersed shapes with a nanoscale size (221–274 nm) and controlled drug release profile. The cytotoxicity effects of LCispt and PLCispt were assessed in an in vitro environment, and the results demonstrated that PLCispt caused a 2.4- and 1.9-fold increase in the cytotoxicity effects of Cispt after 24 and 48 h, respectively. The therapeutic and toxicity effects of the formulations were also assessed on BC-bearing rats. The results showed that PLCispt caused a 4.8-fold increase in the drug efficacy (tumor volume of 11 ± 0.5 and 2.3 ± 0.1 mm³ in Cispt and PLCispt receiver rats, respectively) and a 3.3-fold decrease in the toxicity effects of the drug (bodyweight gains of 3% and 10% in Cispt and PLCispt receiver rats, respectively). The results of toxicity were also confirmed by histopathological studies. Overall, this study suggests that the PEGylation of LCispt is a promising approach to achieve a nanoformulation with enhanced anticancer effects and reduced toxicity compared to Cispt for the treatment of BC.

Therapeutic efficacy and imaging assessment of the HER2-targeting chemotherapy drug ZHER2:V2-pemetrexed in lung adenocarcinoma Xenografts

Chemotherapy has always been the first therapeutic option for patients with advanced non-small cell lung cancer (NSCLC) with untreatable oncogenic mutations. However, chemotherapy has demonstrated limited success and is associated with severe side effects. This research aimed to investigate the antitumor efficacy and cytotoxic safety of the conjugate Z_HER2:V2-pemetrexed, a novel targeted chemotherapeutic drug. In this context, human epidermal growth factor receptor 2 (HER2) + A549 lung xenografts were treated using Z_HER2:V2-pemetrexed, pemetrexed or physiological saline. Therapeutic efficacy was monitored by single photon emission computed tomography (SPECT) imaging using the ^99mTc-labeled Z_HER2:V2-pemetrexed conjugate and further confirmed by performing apoptosis assays using flow cytometry analysis and hematoxylin-eosin (H&E) staining. To evaluate the expression of HER2 in tumor tissues, immunohistochemistry was performed, accompanied by quantitative analysis using flow cytometry. A toxicological evaluation was also conducted. Imaging with ^99mTc-Z_HER2:V2-pemetrexed demonstrated that in HER2+ A549 models, Z_HER2:V2-pemetrexed showed better antineoplastic effects than pemetrexed. Compared with pemetrexed, the results from the pathological and flow cytometry analyses also revealed that Z_HER2:V2-pemetrexed exhibits high antitumor activity against A549 tumors, inducing necrosis, apoptosis and cell cycle arrest. In addition, the clinical signs of toxicity in the Z_HER2:V2-pemetrexed treated group were reduced compared with those in the pemetrexed treated group. These data revealed that the Z_HER2:V2-pemetrexed conjugate encompasses promising targeted antitumor activity against HER2-positive lung adenocarcinoma, with reduced side effects compared with pemetrexed. Thus, the Z_HER2:V2-pemetrexed conjugate may serve as a novel molecular agent with tremendous clinical breakthrough potential in the diagnosis and treatment of HER2-positive lung adenocarcinoma.

Screening and production of an affibody inhibiting the interaction of the PD-1/PD-L1 immune checkpoint

An affibody is a 58 amino acids peptide derived from the Z domain of staphylococcal protein A and generally applied in areas such as imaging diagnosis, clinical therapeutics and biotechnology research. To screen for an affibody targeting the immune checkpoint PD-L1, a combinatorial affibody library was generated in yeast using degenerate overlap PCR primers and In-fusion technology. Z-j1 and Z-j2 affibodies targeting the Ig-like V domain of PD-L1 were screened and identified from this combinatorial library using the yeast two hybrid system. The Z-j1 and Z-j2 recombinant affibody proteins were over produced in E.coli and purified. ELISA and GST pull-down assays showed that recombinant Z-j1 and Z-j2 affibody proteins bound with high affinity to PD-L1 and inhibited the interaction of PD-1/PD-L1. Thus, novel affibodies targeting the immune checkpoint PD-1/PD-L1 were identified and produced in this study and have the potential to be used in cancer immunotherapy.

A high-risk papillomavirus 18 E7 affibody-enabled in vivo imaging and targeted therapy of cervical cancer

High-risk papillomavirus (HPV) is one of the major reasons for cervical cancer, causing most lethal gynecologic malignancies worldwide. For cervical cancer progression, oncogene E7 plays vital roles and is used as one of the major targets for cervical tumor diagnosis and treatment. In the clinic, successful treatment of cervical cancer relies on diagnosing the disease at an early stage, where a late-stage diagnosis usually led to treatment failure. In this work, we designed and purified an HPV18 E7 oncogene targeting affibody, named as Z_HPV18E7, for in vitro and in vivo imaging and targeted treatment of cervical cancer. In vitro, Z_HPV18E7 showed a specific targeting effect against an HPV18 positive cell line; as a contrast, the affibody did not target the HPV18 negative cell line. In vivo, we tested the bio-distribution of the affibody in mice bearing cervical cancer. The whole animal imaging analysis indicated the affibody-targeted tumor tissue specifically with 10 min after injection, and the affibody reached the highest level at tumor tissues 45 min after injection. At the 24th hour after injection, the affibody still maintained a certain level in tumor tissues compared to other organs. To test the therapeutic effect of this affibody, we modified the affibody (i.e., Z_HPV18E7) with a clinically used anti-cancer agent (i.e., Pseudomonas exotoxin). In a mice cervical cancer model, Z_HPV18E7 was able to deliver Pseudomonas exotoxin to tumor tissues effectively, showing great potential for cancer treatment. This study indicated that Z_HPV18E7 could be employed for in vitro imaging and targeted treatment of cervical cancer. Beyond the chemotherapeutic agent used in this work, the affibody could be extended for carrying other therapeutic agents for cervical cancer treatment.

Niosome-loaded antifungal drugs as an effective nanocarrier system: A mini review

Skin is an important organ of the body due to offering an accessible and convenient site for drug administration. One of the disadvantages of transdermal drug delivery is the low penetration rate of drugs through the skin. Over the past decades, nanoparticles have been used as drug delivery systems to increase therapeutic effects or reduce toxicity. Encapsulation of drugs in nanoparticulate vesicles simplifies the transports of drugs into and across the skin.

Niosome nanoparticles are among these drug delivery systems, which have numerous applications in drug delivery and targeting. Niosomes are frequently used for loading drugs serving different purposes (e.g., anticancer, antiviral, and antibacterial agents). In recent years, there has been much research on the use of niosomal systems for the delivery of fungal drugs. A review of the literature investigating the advantages of niosomes in antifungal drug delivery can elucidate the efficiency and superiority of this nanocarrier over other nanocarriers.

Functional Peptide Nanofibers with Unique Tumor Targeting and Enzyme-Induced Local Retention Properties

An effective tumoral delivery system should show minimal removal by the reticuloendothelial system (RES), promote tumor uptake and penetration, and minimize on-site clearance. This study reports the design and synthesis of advanced self-assembling peptide nanofiber precursor (NFP) analogues. The peptidic nature of NFP offers the design flexibility for on-demand customization with imaging agents and surface charges while maintaining a set size, allowing for real-time monitoring of kinetic and dynamic tumoral delivery by multimodal fluorescence/positron emission tomography/computed tomography (fluo/PET/CT) imaging, for formulation optimization. The optimized glutathione (GSH)-NFP displays a reduced capture by the RES as well as excellent tumor targeting and tissue invasion properties compared to naive NFP. Inside a tumor, GSH-NFP can structurally transform into ten times larger interfibril networks, serving as in situ depot that promotes weeks-long local retention. This nanofiber, which can further be designed to release the active pharmacophores within a tumor microenvironment, displays a superior therapeutic efficacy for inhibiting disease progression and improving the survival of animals bearing triple-negative breast cancer tumors compared to free drug and liposome formulation of the drug, in addition to a favorable toxicity profile.

Facilitating the Cellular Accumulation of Pt-Based Chemotherapeutic Drugs

Cisplatin, carboplatin, and oxaliplatin are Pt-based drugs used in the chemotherapeutic eradication of cancer cells. Although most cancer patient cells initially respond well to the treatment, the clinical effectiveness declines over time as the cancer cells develop resistance to the drugs. The Pt-based drugs are accumulated via membrane-bound transporters, translocated to the nucleus, where they trigger various intracellular cell death programs through DNA interaction. Here we illustrate how resistance to Pt-based drugs, acquired through limitation in the activity/subcellular localization of canonical drug transporters, might be circumvented by the facilitated uptake of Pt-based drug complexes via nanocarriers/endocytosis or lipophilic drugs by diffusion.

Surface Functionalization and Targeting Strategies of Liposomes in Solid Tumor Therapy: A Review

Surface functionalization of liposomes can play a key role in overcoming the current limitations of nanocarriers to treat solid tumors, i.e., biological barriers and physiological factors. The phospholipid vesicles (liposomes) containing anticancer agents produce fewer side effects than non-liposomal anticancer formulations, and can effectively target the solid tumors. This article reviews information about the strategies for targeting of liposomes to solid tumors along with the possible targets in cancer cells, i.e., extracellular and intracellular targets and targets in tumor microenvironment or vasculature. Targeting ligands for functionalization of liposomes with relevant surface engineering techniques have been described. Stimuli strategies for enhanced delivery of anticancer agents at requisite location using stimuli-responsive functionalized liposomes have been discussed. Recent approaches for enhanced delivery of anticancer agents at tumor site with relevant surface functionalization techniques have been reviewed. Finally, current challenges of functionalized liposomes and future perspective of smart functionalized liposomes have been discussed.

Affibody molecules for molecular imaging and targeted drug delivery in the management of breast cancer

Breast cancer is one of the leading reasons for the morbidity and mortality of cancer related death globally. The modern therapies are basically the combination of the breast-preserving surgeries or ablation with or without node biopsy or destroying the carcinoma cells adjuvant with chemotherapy, radiotherapy, hormonal or biological therapies depending upon the nature of the receptor of the cancerous cells, nature of the lymph node, as well as the tendency of the recurrence. For decade's carcinoma management suffered by the limitation of imagining, targeting and penetrability problem associated with management and cure of this deadly disease leads to unwanted chemo-toxicity and side effects. Alike other antibody mimetics, affibodies are designed with the combinatorial protein engineering approaches which are small and robust protein scaffolds retaining the favorable folding and stability. Affibody is one of the significantly important tools for imaging and diagnosis of the affinity specific over expressed proteins in the breast cancer management. The review summarizes the various affibody strategies uses in the management of breast cancer.

Affibody Molecules in Biotechnological and Medical Applications

Affibody molecules are small (6.5-kDa) affinity proteins based on a three-helix bundle domain framework. Since their introduction 20 years ago as an alternative to antibodies for biotechnological applications, the first therapeutic affibody molecules have now entered clinical development and more than 400 studies have been published in which affibody molecules have been developed and used in a variety of contexts. In this review, we focus primarily on efforts over the past 5 years to explore the potential of affibody molecules for medical applications in oncology, neurodegenerative, and inflammation disorders, including molecular imaging, receptor signal blocking, and delivery of toxic payloads. In addition, we describe recent examples of biotechnological applications, in which affibody molecules have been exploited as modular affinity fusion partners.

In vitro antitumor activity of patulin on cervical and colorectal cancer cell lines

Background and Purpose:

Patulin is a mycotoxin produced by some molds, especially Aspergillus and Penicilium, and is responsible for mycotoxicosis in animals and humans.

There is still not very detailed data about the anti-cancer potency of patulin, but some reports demonstrated that it induces cellular apoptosis and toxicity.

Materials and Methods:

To determine the efficacy of patulin as a therapeutic strategy for cervical and colorectal cancers, we investigated its effects on HeLa,SW-48, and MRC-5 cell lines. Cell lines were exposed to various concentrations of patulin (i.e., 0.5, 1, 2, and 4 µM), then using methyl thiazolyl tetrazolium (MTT) and bromo-2′-deoxyuridine (BrdU) assays, the rates of apoptosis and cell viability were determined.

Results:

The obtained results showed a significant reduction in cell viability and apoptosis induction in a dose-dependent manner. Among all the cell lines, the highest growth inhibition rate was obtained at the 4 μM concentration of patulin.

Conclusion:

Our results suggested that patulin could significantly decrease tumor growth in human cervical and colorectal cancer models.

In vitro antitumor activity of patulin on cervical and colorectal cancer cell lines

BACKGROUND AND PURPOSE

Patulin is a mycotoxin produced by some molds, especially Aspergillus and Penicilium, and is responsible for mycotoxicosis in animals and humans.There is still not very detailed data about the anti-cancer potency of patulin, but some reports demonstrated that it induces cellular apoptosis and toxicity.

MATERIALS AND METHODS

To determine the efficacy of patulin as a therapeutic strategy for cervical and colorectal cancers, we investigated its effects on HeLa,SW-48, and MRC-5 cell lines. Cell lines were exposed to various concentrations of patulin (i.e., 0.5, 1, 2, and 4 µM), then using methyl thiazolyl tetrazolium (MTT) and bromo-2'-deoxyuridine (BrdU) assays, the rates of apoptosis and cell viability were determined.

RESULTS

The obtained results showed a significant reduction in cell viability and apoptosis induction in a dose-dependent manner. Among all the cell lines, the highest growth inhibition rate was obtained at the 4 μM concentration of patulin.

CONCLUSION

Our results suggested that patulin could significantly decrease tumor growth in human cervical and colorectal cancer models.