Ratiometric co-encapsulation and co-delivery of doxorubicin and paclitaxel by tumor-targeted lipodisks for combination therapy of breast cancer

Dual centrifugation as a novel and efficient method for the preparation of lipodisks

Polyethylene glycol (PEG)-stabilized lipodisks have emerged as innovatiive, promising nanocarriers for several classes of drugs. Prior research underscores the important role of lipid composition and preparation method in determining the lipodisk size, uniformity, and drug loading capacity. In this study, we investigate dual centrifugation (DC) as a novel technique for the production of PEG-stabilized lipodisks. Moreover, we explore the potential use of DC for the encapsulation of two model drugs, curcumin and doxorubicin, within the disks. Our results show that by a considerate choice of experimental conditions, DC can be used as a fast and straightforward means to produce small and homogenous lipodisks with a hydrodynamic diameter of 20-30 nm. Noteworthy, the technique works well for the production of both cholesterol-free and cholesterol-containing disks and does not require pre-mixing of the lipids in organic solvent. Furthermore, our investigations confirm the efficacy of DC in formulating curcumin and doxorubicin within these lipodisks. For doxorubicin, careful control and optimization of the experimental conditions resulted in formulations displaying an encouraging encapsulation efficiency of 84 % and a favourable drug-to-lipid ratio of 0.13 in the disks.

Knockout of KDM3A in MDA-MB-231 breast cancer cells inhibits tumor malignancy and promotes apoptosis

The histone lysine demethylase 3 A (KDM3A) is vital for the regulation of cancer physiology and pathophysiology. The purpose of this study was to investigate the effect of KDM3A expression with triple-negative breast cancer (TNBC) invasion and metastasis. In our results, knockout of KDM3A in TNBC MDA-MB-231 cells promoted apoptosis and inhibited the proliferation, invasion and metastasis of MDA-MB-231 cells. In addition, we found that in vivo experiments indicated that the growth, invasion and metastasis of metastatic neoplasms were significantly inhibited by knockout of KDM3A in a TNBC metastasis model. These findings suggest that KDM3A may be a potential therapeutic target for the treatment and prevention of TNBC, providing a critical theoretical basis for the effective prevention or treatment of breast cancer disease.

Applications of lipid-engineered nanoplatforms in the delivery of various cancer therapeutics to surmount breast cancer

Breast cancer (BC) is the most extensively accounted malignancy among the women across the globe and is treatable in 70-80% of patients with early-stage, non-metastatic cancer. The current available therapies have been found to be less effective to treat distant organ metastases and advanced breast cancers. The clinical efficacy hugely suffers from chemoresistance, non-specific toxicity, relapse and other associated adverse effects. Furthermore, lack of controlled delivery and effective temporospatial presence of chemotherapeutics has resulted in suboptimal therapeutic response. Nanotechnology based approaches have been widely used over the period as they are nanometric, offer controlled and site-specific drug release along with reduced toxicity, improved half-life, and stability. Lipid-based nanoplatforms have grabbed a tremendous attention for delivering cancer therapeutics as they are cost-effective, scalable and provide better entrapment efficiency. In this review, all the promising applications of lipid-engineered nanotechnological tools for breast cancer will be summarized and discussed. Subsequently, BC therapy achieved with the aid of chemotherapeutics, phytomedicine, genes, peptides, photosensitizers, diagnostic and immunogenic agents etc. will be reviewed and discussed. This review gives tabular information on all the results obtained pertaining to the physicochemical properties of the lipidic nanocarrier, in vitro studies conferring to mechanistic drug release profile, cell viability, cellular apoptosis and in vivo studies referring to cellular internalisation, reduction of tumor volume, PK-PD profile, bioavailability achieved and anti-tumor activity in detail. It also gives complete information on the most relevant clinical trials done on lipidic nanoplatforms over two decades in tabular form. The review highlights the current status and future prospects of lipidic nanoplatforms with streamlined focus on cancer nanotherapeutics.

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

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

Potential of Ferritin-Based Platforms for Tumor Immunotherapy

Ferritin is an iron storage protein that plays a key role in iron homeostasis and cellular antioxidant activity. Ferritin has many advantages as a tumor immunotherapy platform, including a small particle size that allows for penetration into tumor-draining lymph nodes or tumor tissue, a unique structure consisting of 24 self-assembled subunits, cavities that can encapsulate drugs, natural targeting functions, and a modifiable outer surface. In this review, we summarize related research applying ferritin as a tumor immune vaccine or a nanocarrier for immunomodulator drugs based on different targeting mechanisms (including dendritic cells, tumor-associated macrophages, tumor-associated fibroblasts, and tumor cells). In addition, a ferritin-based tumor vaccine expected to protect against a wide range of coronaviruses by targeting multiple variants of SARS-CoV-2 has entered phase I clinical trials, and its efficacy is described in this review. Although ferritin is already on the road to transformation, there are still many difficulties to overcome. Therefore, three barriers (drug loading, modification sites, and animal models) are also discussed in this paper. Notwithstanding, the ferritin-based nanoplatform has great potential for tumor immunotherapy, with greater possibility of clinical transformation.

Preclinical toxicological study of long-circulating and fusogenic liposomes co-encapsulating paclitaxel and doxorubicin in synergic ratio

Combination therapy between paclitaxel (PTX) and doxorubicin (DXR) is applied as the first-line treatment of breast cancer. Co-administration of drugs at synergistic ratio for treatment is facilitated with the use of nanocarriers, such as liposomes. However, despite the high response rate of solid tumors to this combination, a synergism of cardiotoxicity may limit the use. Thus, the objective of this work was to investigate the toxicity of long-circulating and fusogenic liposomes co-encapsulating PTX and DXR at the synergistic molar ratio (1:10) (LCFL-PTX/DXR). For this, clinical chemistry, histopathological analysis and electrocardiographic exams were performed on female Balb/c mice that received a single intravenous dose of LCFL-PTX/DXR. The results of the study indicated that the LD50 dose range (lethal dose for 50% of animals) of the LCFL-PTX/DXR treatment (28.9-34.7 mg/kg) is much higher than that found for free PTX/DXR treatment (20.8-23.1 mg/kg). In addition, liposomes promoted cardiac protection by not raising CK-MB levels in animals, keeping cardiomyocytes without injury or electrocardiographic changes. After 14 days of treatment, free PTX/DXR caused prolongation of the QRS interval when compared to LCFL-PTX/DXR treatment at the same dose (37.0 ± 5.01 ms and 30.83 ± 2.62 ms, respectively, with p = 0.017). The survival rate of animals treated with LCFL-PTX/DXR was three times higher than that of those treated with free drugs. Thus, it was established that the toxicity of LCFL-PTX/DXR is reduced compared to the combination of free PTX/DXR and this platform has advantages for the clinical treatment of breast cancer.

An Efficient Carbon-Based Drug Delivery System for Cancer Therapy through the Nucleus Targeting and Mitochondria Mediated Apoptotic Pathway

The emergence of nanocarriers solves the problems of antitumor drugs such as non-targeting, huge side effects, etc., and has been widely used in tumor therapy. Some kinds of antitumor drugs such as doxorubicin (DOX) mainly act on the nucleic acid causing DNA damage, interfering with transcription, and thereby disrupting or blocking the process of cancer cell replication. Herein, a new nanodrug delivery system, the carbon-based nanomaterials (CBNs)-Pluronic F127-DOX (CPD), is designed by using CBNs as a nanocarrier for DOX. As a result, the tumor growth inhibition rate of CPD group is as high as 79.42 ± 2.83%, and greatly reduces the side effects. The targeting rate of the CPD group of DOX in the tumor nucleus is 36.78%, and the %ID/g in tumor tissue is 30.09%. The CPD regulates the expression levels of Caspase-3, p53, and Bcl-2 genes by increasing intracellular reactive oxygen species (ROS) levels and reducing mitochondrial membrane potential, which indicates that mitochondrial-mediated pathways are involved in apoptosis. The CPD nanodrug delivery system increases the effective accumulation of DOX in tumor cell nuclei and tumor tissues, and generates massive ROS, thereby inhibiting tumor growth in vivo, representing a promising agent for anticancer applications.

A Systematic Approach for Liposome and Lipodisk Preclinical Formulation Development by Microfluidic Technology

Lipid nanoparticles have transformed the drug delivery field enhancing the therapeutic drug performance of small molecules and biologics with several approved drug products. However, in industry, these more complex drug delivery systems such as liposomes require more material and time to develop. Here, we report a liposome and lipodisk decision tree with model compounds of diverse physicochemical properties to understand how to resourcefully optimize encapsulation efficiency (EE) for these lipid-based drug delivery systems. We have identified trends with physicochemical properties such as Log P, where higher Log P compounds such as curcumin were able to efficiently load into the lipid bilayer resulting in high EE with altering the drug/lipid (D/L) ratio. Moderate Log P compounds such as cyclosporine A and dexamethasone had significantly higher encapsulation in lipodisks, which contain higher amounts of PEG lipid compared to liposomes. The EE of negative Log P compounds, like acyclovir, remained low regardless of altering the D/L ratio and PEG concentrations. In this study, microfluidic techniques were employed to fabricate liposomes and lipodisks formulations allowing for a reproducible strategy for formulation development. Both liposome and lipodisk of curcumin demonstrated enhanced in vivo performance compared with a conventional formulation in the rat pharmacokinetic study. This combination of approaches with multiple model compounds and lipid-based drug delivery systems provides a systematic guidance to effective strategies to generate higher EE with minimal drug waste and expedite the process for preclinical development when applied to industry compounds.

A Study of Hydrophobically Modified Pullulan Nanoparticles with Different Hydrophobic Densities on the Effect of Anti-Colon Cancer Cell Efficiency

To discuss the effect of hydrophobic groups of a polymer on the structural properties and function of polymer nanoparticles (NPs), we grafted chenodeoxycholic acid (CDCA) with pullulan (PU) to form hydrophobically modified PU (PUC). Three PUC polymers, namely, PUC-1, PUC-2, and PUC-3, with different degrees of substitution were designed by changing the feed ratio of CDCA and PU. ¹H-NMR spectra showed that the PUC polymer was successfully synthesized, and the degrees of hydrophobic substitution for PUC-1, PUC-2, and PUC-3 were calculated to be 10.66%, 13.92%, and 16.94%, respectively. The PUC NPs were prepared by the dialysis method and were shown to be uniformly spherical by transmission electron microscopy (TEM). The average sizes were about (220±10) nm, (203±7) nm, and (163±6) nm under dynamic light scattering (DLS) for PUC-1 NPs, PUC-2 NPs, and PUC-3 NPs, respectively. Drug release experiments showed that the three PUC/DOX NPs exhibited good sustained release. At 48 h, the IC₅₀ of doxorubicin in inhibiting colon cancer HCT116 cells was 0.0904 μg/mL. A cell study showed that PUC-3/DOX NPs had the highest uptake efficiency by HCT116 cells with the most cytotoxicity and inhibited the migration of HCT116 cells with the highest efficiency. The structural properties and function of polymer NPs were closely related to the hydrophobic groups in the polymer, and NPs with higher hydrophobicity showed a smaller size, higher drug capacity, and greater cell efficiency.

A convergent synthetic platform for polymeric nanoparticle for the treatment of combination colorectal cancer therapy

In biomaterials and drug delivery, the development of polymeric therapies capable of the synchronized release of several therapeutic agents remains an important challenge. In this article, we describe the development of polymeric nanoparticles (PNPs) with precise molar ratios of Curcumin (CUR) and Methotrexate (MEX). The highly symmetric synthetic approach allows for the development of novel NPs-based combination therapeutic strategies for colorectal cancer. The fabricated CUR/MEX@PNPs were confirmed by transmission microscopy (TEM) and the size and polydispersity index were assessed through the dynamic light scattering (DLS). CUR and MEX were released slowly from the drug delivery without any burst impact. Furthermore, CUR/MEX@PNPs exhibited dose-responsive cytotoxic effects in CL40 and SW1417 cells, with a greater cell death ratio than that of free drugs. The drugs-loaded polymeric nanomaterials were more easily taken up by cancer cells in vitro, according to the cellular uptake analysis. The apoptotic features were confirmed by various fluorescence staining assay. The results of the fluorescent assay reveal that the nanomaterials remarkably induce apoptosis in colorectal cancer cells. Further, the apoptosis cell death mechanism was displayed that these nanomaterials significantly induce apoptosis in the targeted cancer cells. Overall, the current investigation confirmed that CUR/MEX@PNPs could be used to successfully combat colorectal cancers in the immediate future.HighlightsWe have developed the Curcumin (CUR) and Methotrexate (MEX) encapsulated polymeric nanoparticles (CUR/MEX@PNPs).CUR/MEX@PNPs confirmed by the various analytical methods.CUR/MEX@PNPs enhanced the in vitro proliferation against the colorectal cancer cells.Biochemical analysis results reveals that CUR/MEX@PNPs induce apoptosis.The apoptosis was confirmed by Annexin-V-FITC and PI for flow cytometry.

Co-delivery of doxorubicin and paclitaxel by reduction/pH dual responsive nanocarriers for osteosarcoma therapy

Nanoparticle-based drug delivery system offers a promising platform for combination cancer therapy. However, the inefficient drug release in cells reduces the therapeutic efficacy of cancer nanomedicines. Herein, a PEGylated poly(α-lipoic acid) copolymer (mPEG-PαLA) was prepared and used as a reduction/pH dual responsive nanocarrier to simultaneously deliver paclitaxel (PTX) and doxorubicin (DOX) for osteosarcoma therapy. The amphiphilic mPEG-PαLA could efficiently encapsulate both PTX and DOX during its self-assembly into micelles in aqueous solution to generate PTX and DOX co-loaded nanoparticles (NP-PTX-DOX). The as-prepared NP-PTX-DOX showed enhanced PTX and DOX release in response to reductive and acidic stimuli. Moreover, the dual-drug loaded nanoparticles were efficiently internalized by K7 osteosarcoma cells and released drugs intracellularly, as confirmed by flow cytometry analysis and confocal laser scanning microscopy. Consequently, NP-PTX-DOX exhibited synergistic therapeutic effects and induced enhanced cell apoptosis in K7 cells. Furthermore, NP-PTX-DOX presented improved biodistribution and higher tumor growth inhibition efficacy compared to the control groups in a murine osteosarcoma model. Altogether, the results of this work indicate that the proposed strategy is promising for osteosarcoma therapy using mPEG-PαLA copolymer as a dual-responsive nanocarrier to co-deliver anticancer drugs.

Nanomaterials to Fight Cancer: An Overview on Their Multifunctional Exploitability

In recent years the worldwide research community has highlighted innumerable benefits of nanomaterials in cancer detection and therapy. Nevertheless, the development of cancer nanomedicines and other bionanotechnology requires a huge amount of considerations about the interactions of nanomaterials and biological systems, since long-term effects are not yet fully known. Open issues remain the determination of the nanoparticles distributions patterns and the internalization rate into the tumor while avoiding their accumulation in internal organs or other healthy tissues. The purpose of this work is to provide a standard overview of the most recent advances in nanomaterials to fight cancer and to collect trends and future directions to follow according to some critical aspects still present in this field. Complementary to the very recent review of Wolfram and Ferrari which discusses and classifies successful clinically-approved cancer nanodrugs as well as promising candidates in the pipeline, this work embraces part of their proposed classification system based on the exploitation of multifunctionality and extends the review to peer-reviewed journal articles published in the last 3 years identified through international databases.

Lipid nanocapsules co-encapsulating paclitaxel and salinomycin for eradicating breast cancer and cancer stem cells

Cancer stem cells (CSCs) comprise a diminutive population of the tumor but pose major obstacles in cancer treatment, often their presence being correlated with poor prognosis, therapeutic resistance and relapse. Nanocarriers of combined drugs regimes demonstrate improved pharmacokinetics and decreased systemic toxicity by targeting the bulk tumor cells along with CSCs, holding the key to future successful chemotherapy. Herein, we developed lipid nanocapsules (LNCs) with co-encapsulated paclitaxel (PTX) and salinomycin (SAL) to eliminate breast cancer cells (MCF-7; non-bCSCs) and cancer stem cells (bCSCs) respectively. LNCs loaded with either PTX or SAL alone or in combination were fabricated by the phase inversion temperature (PIT) method. Physicochemical properties such as nano-size (90 ± 5 nm) and spherical morphology of LNCs were confirmed by dynamic light scattering (DLS) and scanning electron microscopy (SEM) respectively. More than 98 % encapsulation efficiency of drug, alone or in combination, and their controlled drug release was obtained. Drug loaded LNCs were efficiently internalized and exhibited cytotoxicity in non-bCSCs and bCSCs, with dual drug loaded LNCs offering superior cytotoxicity and anti-bCSCs property. Drug loaded nanocapsules induced apoptosis in bCSCs, potentiated with the co-delivery of paclitaxel and salinomycin. Synergistic cytotoxic effect on both cells, non-bCSCs and bCSCs and effective reduction of the tumor mammospheres growth by co-encapsulated paclitaxel and salinomycin suggest LNCs to be promising for treatment of breast cancer.

Recent Advances of Taxol-Loaded Biocompatible Nanocarriers Embedded in Natural Polymer-Based Hydrogels

The discovery of paclitaxel (PTX) has been a milestone in anti-cancer therapy and has promoted the development and marketing of various formulations that have revolutionized the therapeutic approach towards several malignancies. Despite its peculiar anti-cancer activity, the physico-chemical properties of PTX compromise the administration of the compound in polar media. Because of this, since the development of the first Food and Drug Administration (FDA)-approved formulation (Taxol®), consistent efforts have been made to obtain suitable delivery systems able to preserve/increase PTX efficacy and to overcome the side effects correlated to the presence of some excipients. The exploitation of natural polymers as potential materials for drug delivery purposes has favored the modulation of the bioavailability and the pharmacokinetic profiles of the drug, and in this regard, several formulations have been developed that allow the controlled release of the active compound. In this mini-review, the recent advances concerning the design and applications of natural polymer-based hydrogels containing PTX-loaded biocompatible nanocarriers are discussed. The technological features of these formulations as well as the therapeutic outcome achieved following their administration will be described, demonstrating their potential role as innovative systems to be used in anti-tumor therapy.

A multiple acetal chalcone-BODIPY-based fluorescence: synthesis, physical property, and biological studies

Fluorescent probes with outstanding physical and biological properties are superior for functional fluorescent dyes design. However, few studies pay attention to the stability of specific groups in fluorescent probes. The aldehyde group in the fluorescent probe is highly active but unstable under certain conditions. Therefore, we introduced ethoxy groups to realize the conversion to aldehyde groups under acidic conditions and avoid the instability of straightforward aldehyde groups. In this work, two fluorophores based on the multi acetal difluoroboraindacene (BODIPY) units with combination of the pharmaceutical intermediate chalcone have been firstly developed. In the design part, chalcone was introduced as a medium for fluorophore and multiple acetal. The mild synthesis strategy is based on the ligand ((Z)-2-chloro-1-(difluoroboranyl)-5-((4-ethyl-3,5-dimethyl-2H-pyrrol-2-ylidene)(phenyl)methyl)-1H-pyrrole) and connects with chalcone in (2E,2'E)-3,3'-(1,3-phenylene)bis(1-(2,4-bis(2,2-diethoxyethoxy)phenyl)prop-2-en-1-one). The emission wavelengths of the products are around 530 nm with high fluorescence intensity. To highlight the biological characteristics of these novel BODIPY fluorescents, we further demonstrated biological analysis studies on MTT and flow cytometry assays. The IC₅₀ values of BODIPY 5 ranged from 79 ± 6.11 to 63 ± 5.67 μM and BODIPY 6 were found to be 86 ± 4.07 to 58 ± 10.51 μM in tested cell lines. Flow cytometry data analysis shows that the representative agent 6 and reference have similar rational apoptosis rates in first quadrant. Last but not least, 6 shows outstanding biological compatibility and cell imaging potential in live cell imaging and in vivo assay, not only is the fluorescence prominent enough, but also rapidly distributes. Thus, our study reports a mild synthesis strategy and full biological analysis on BODIPY fluorescents, and the subtle modulation of the physical and biological properties by pharmaceutical substituents makes these designed chalcone-BODIPY-based dyes hopeful to realize drug functional fluorescent dyes. Two new highly sensitive BODIPY fluorophores are synthesized based on the ligand ((Z)-2-chloro-1-(difluoroboranyl)-5-((4-ethyl-3,5-dimethyl-2H-pyrrol-2-ylidene)(phenyl)methyl)-1H-pyrrole), which connects with chalcone in (2E,2'E)-3,3'-(1,3/4-phenylene)bis(1-(2,4-bis(2,2-diethoxyethoxy)phenyl)prop-2-en-1-one). Multiple acetals were introduced and the physical and biological properties of BODIPYs are described with MTT assay and in vitro and in vivo imaging.

Macrocyclic-Amphiphile-Based Self-Assembled Nanoparticles for Ratiometric Delivery of Therapeutic Combinations to Tumors

Combination chemotherapy refers to the use of multiple drugs to treat cancer. In this therapy, the optimal ratio of the drugs is essential to achieve drug synergism and the desired therapeutic effects. However, most delivery strategies are unable to precisely control the ratio of the drugs during the drug loading and delivery processes, resulting in inefficient synergy and unpredictable efficacy. Herein, a macrocyclic-amphiphile-based self-assembled nanoparticle (MASN) that achieves precise loading and ratiometric delivery of therapeutic combinations is presented. By integrating multiple macrocyclic cavities within a single nanoparticle, the MASN can load multiple drug molecules via the host-guest interaction, and the ratio of the drugs loaded can be predicted with their initial concentrations and characteristic binding affinity. Moreover, MASNs are readily degraded under a hypoxic microenvironment, allowing spontaneous release of the drugs upon reaching tumor tissues. With precise drug loading and controlled release mechanisms, MASNs achieve ratiometric delivery of multiple commercial drugs to tumors, thereby achieving optimal anti-tumor effects. Since the optimal drug ratio of a therapeutic combination can be quickly determined in vitro, MASNs can translate this optimal ratio to the therapeutic benefits in vivo, providing a potential platform for the rapid development of effective combination cancer therapies involving multiple drugs.

The Phospholipid Research Center: Current Research in Phospholipids and Their Use in Drug Delivery

This review summarizes the research on phospholipids and their use for drug delivery related to the Phospholipid Research Center Heidelberg (PRC). The focus is on projects that have been approved by the PRC since 2017 and are currently still ongoing or have recently been completed. The different projects cover all facets of phospholipid research, from basic to applied research, including the use of phospholipids in different administration forms such as liposomes, mixed micelles, emulsions, and extrudates, up to industrial application-oriented research. These projects also include all routes of administration, namely parenteral, oral, and topical. With this review we would like to highlight possible future research directions, including a short introduction into the world of phospholipids.

Remote loading paclitaxel-doxorubicin prodrug into liposomes for cancer combination therapy

The combination of paclitaxel (PTX) and doxorubicin (DOX) has been widely used in the clinic. However, it remains unsatisfied due to the generation of severe toxicity. Previously, we have successfully synthesized a prodrug PTX-S-DOX (PSD). The prodrug displayed comparable in vitro cytotoxicity compared with the mixture of free PTX and DOX. Thus, we speculated that it could be promising to improve the anti-cancer effect and reduce adverse effects by improving the pharmacokinetics behavior of PSD and enhancing tumor accumulation. Due to the fact that copper ions (Cu²⁺) could coordinate with the anthracene nucleus of DOX, we speculate that the prodrug PSD could be actively loaded into liposomes by Cu²⁺ gradient. Hence, we designed a remote loading liposomal formulation of PSD (PSD LPs) for combination chemotherapy. The prepared PSD LPs displayed extended blood circulation, improved tumor accumulation, and more significant anti-tumor efficacy compared with PSD NPs. Furthermore, PSD LPs exhibited reduced cardiotoxicity and kidney damage compared with the physical mixture of Taxol and Doxil, indicating better safety. Therefore, this novel nano-platform provides a strategy to deliver doxorubicin with other poorly soluble antineoplastic drugs for combination therapy with high efficacy and low toxicity.

Tumor-Targeted Delivery of the p53-Activating Peptide VIP116 with PEG-Stabilized Lipodisks

Stapled peptides targeting the interaction between p53 and its negative regulators MDM2 and MDM4 have exhibited great potential as anti-cancer drugs, albeit with room for improvement in formulation and tumor specificity. Lipid bilayer disks (lipodisks) have emerged as promising drug nanocarriers and can by attachment of targeting moieties be directed selectively towards tumor cells. Tumor-targeted delivery of stapled peptides by use of lipodisks may therefore increase the uptake in the tumors and limit toxicity in healthy tissue. Here, we utilized epidermal growth factor receptor (EGFR)-targeted lipodisks to deliver p53-activating stapled peptide VIP116 to EGFR-expressing tumor cells. We demonstrate that VIP116 can be stably formulated in lipodisks (maximum peptide/lipid molar ratio 0.11). In vitro cell studies verify specific binding of EGF-decorated lipodisks to tumor cells and confirm that targeted delivery of VIP116 significantly decreases tumor cell viability.

Dual Peptide-Modified Nanoparticles Improve Combination Chemotherapy of Etoposide and siPIK3CA Against Drug-Resistant Small Cell Lung Carcinoma

Small cell lung carcinoma (SCLC) is a highly aggressive form of malignancy with rapid recurrence and poor prognosis. The dual peptide-modified nanoparticles (NPs) for improving chemotherapy against drug-resistant small cell lung carcinoma cells has been developed. In this study, the SCLC targeting ligand, antagonist G peptide (AG), and cell-penetrating peptide, TAT, modified NPs were used to encapsulate both anticancer drugs etoposide (ETP) and PIK3CA small-interfering RNA (siPIK3CA). The ETP@NPs and siRNA@NPs had particle size 201.0 ± 1.9-206.5 ± 0.7 nm and 155.3 ± 12.4-169.1 ± 11.2 nm, respectively. The lyophilized ETP@NPs and siRNA@NPs maintained their particle size and zeta potential during 28-day storage without severe aggregation or dissociation. Either ETP@NPs or siRNA@NPs significantly reduced the IC₅₀ of drugs by 2.5-5.5 folds and 2.4-3.9 folds, respectively, as compared to free ETP and siRNA/PEI nanocomplex in drug-resistant CD133(+) H69 cells. Herein, the IC₅₀ of dual-peptide modified ETP@NPs and siRNA@NPs were prominently lower than single-peptide modified NPs. The synergistic effect (CI < 1) was further observed in co-treatment of ETP and siPIK3CA particularly delivered by dual-peptide modified NPs.

Preparation, characterization and preliminary pharmacokinetic study of pH-sensitive Hydroxyapatite/Zein nano-drug delivery system for doxorubicin hydrochloride

OBJECTIVES

Zein nanoparticles (Zein NPs) were used as a hydroxyapatite (HA) biomineralization template to generate HA/Zein NPs. Doxorubicin hydrochloride (DOX) was loaded on HA/Zein NPs (HA/Zein-DOX NPs) to improve its pH-sensitive release, bioavailability and decrease cardiotoxicity.

METHODS

HA/Zein-DOX NPs were prepared by phase separation and biomimetic mineralization method. Particle size, polydispersity index (PDI), Zeta potential, transmission electron microscope, X-ray diffraction and Fourier-transform infrared spectroscopy of HA/Zein-DOX NPs were characterized. The nanoparticles were then evaluated in vitro and in vivo.

KEY FINDINGS

The small PDI and high Zeta potential demonstrated that HA/Zein-DOX NPs were a stable and homogeneous dispersed system and that HA was mineralized on Zein-DOX NPs. HA/Zein-DOX NPs showed pH-sensitive release. Compared with free DOX, HA/Zein-DOX NPs increased cellular uptake which caused 7 times higher in-vitro cytotoxicity in 4T1 cells. Pharmacokinetic experiments indicated the t_1/2β and AUC_{0- t} of HA/Zein-DOX NPs were 2.73- and 3.12-fold higher than those of DOX solution, respectively. Tissue distribution exhibited HA/Zein-DOX NPs reduced heart toxicity with lower heart targeting efficiency (18.58%) than that of DOX solution (37.62%).

CONCLUSION

In this study, HA/Zein-DOX NPs represented an antitumour drug delivery system for DOX in clinical tumour therapy with improved bioavailability and decreased cardiotoxicity.

Amyloid precursor protein promotes the migration and invasion of breast cancer cells by regulating the MAPK signaling pathway

To verify whether amyloid precursor protein (APP) affects the migration and invasion of breast cancer cell lines, and to understand its underlying mechanisms, epithelial-mesenchymal transition (EMT), the mitogen-activated protein kinase (MAPK) signaling pathway and the matrix metalloproteinase (MMP) family were investigated in MDA-MB-231, MCF-7 and BT474 human breast cancer cells. Breast cancer cell lines were transfected with plasmids containing APP coding sequences (pEGFP-n1-APP) and APP short hairpin RNA (pENTR APP shRNA). APP overexpres-sion efficiency, knockout efficiency and the expression levels of related genes were tested using reverse transcription-quantitative PCR (RT-qPCR) and western blot analyses. The effects of APP and mitogen-activated protein kinase kinase (MEK) inhibitor on cell migration and invasion were examined using Transwell assays. The results demonstrated that APP was significantly upregulated in the pEGFP-n1-APP group (P<0.05), and significantly downregulated in the pENTR APP shRNA group (P<0.05), compared with the control group. APP overexpression increased the migratory and invasive ability of human breast cancer cells (P<0.05), whereas APP silencing significantly inhibited cell migration and invasion (P<0.05). RT-qPCR and western blot analysis results suggested that APP overexpression significantly increased the expression of MMP-9, MMP-2, MMP-3, N-cadherin and vimentin (P<0.05). In addition, the enhanced expression of APP markedly affected the phosphorylation of mitogen-activated protein kinase kinase kinase 11 (MLK3), mitogen-activated protein kinase kinase 4 (MEK4) and mitogen-activated protein kinase 10 (JNK3; P<0.05). Additionally, APP overexpression had no effect on the total expression levels of MLK3, MEK4, and JNK3; however, APP overexpression significantly decreased the expression levels of E-cadherin and cytokeratin (P<0.05). Conversely, APP silencing had the opposite effects. When cells were treated with the MEK inhibitor PD0325901, the expression of APP was not altered, nor was the expression levels of MEK and its upstream signaling molecules. Taken together, the present findings suggested that APP could affect the migration and invasion of human breast cancer cells by mediating the activation of the MAPK signaling pathway, thereby promoting the EMT process.

Synergistically Enhanced Inhibitory Effects of Pullulan Nanoparticle-Mediated Co-Delivery of Lovastatin and Doxorubicin to Triple-Negative Breast Cancer Cells

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that is prone to drug resistance and difficult to treat. In this study, we grafted water-soluble pullulan with lovastatin (LV) to develop a novel amphiphilic conjugate, pullulan-encapsulated LV (PLV). The PLV conjugate was synthesized with three different ratios of pullulan to LV and characterized by Fourier transform infrared (FTIR). The degree of substitution (DS) of LV in terms of molar ratio was 7.87%, 3.58%, and 3.06% for PLV (1/2), PLV (1/3), and PLV (1/4), respectively, by proton NMR analysis. We selected the PLV (1/2) conjugate to prepare doxorubicin (DXR)-loaded PLV nanoparticles (PLV/DXR NPs) because of its superior properties. The average size and zeta potential for PLV (1/2) NPs were 177.6 nm and - 11.66 mV, respectively, determined by dynamic light scattering, and those for PLV/DXR NPs were 225.6 nm and - 10.51 mV, respectively. In vitro drug release profiling showed that PLV/DXR NPs sustainably released DXR within 72 h, which was more robust at pH 5.4 (97.90%) than pH 7.4 (76.15%). In the cytotoxicity study, PLV/DXR NPs showed greater inhibition of proliferation of TNBC MDA-MB-231 than non-TNBC MDA-MB-453 cells (IC₅₀ 0.60 vs 11.05 μM). FITC-loaded PLV/DXR NPs were prepared to investigate cellular uptake: both cell lines showed a time-dependent uptake of NPs, but the number of NPs entering MDA-MB-231 cells was greater than that entering the MDA-MB-453 cells. Pullulan-based NP co-delivery of LV and DXR could efficiently inhibit TNBC cells, which may help in designing a powerful drug delivery system for treating TNBC.