Overcoming biological barriers by virus-like drug particles for drug delivery.

Virus-like particles (VLPs) have natural structural antigens similar to those found in viruses, making them valuable in vaccine immunization. Furthermore, VLPs have demonstrated significant potential in drug delivery, and emerged as promising vectors for transporting chemical drug, genetic drug, peptide/protein, and even nanoparticle drug. With virus-like permeability and strong retention, they can effectively target specific organs, tissues or cells, facilitating efficient intracellular drug release. Further modifications allow VLPs to transfer across various physiological barriers, thus acting the purpose of efficient drug delivery and accurate therapy. This article provides an overview of VLPs, covering their structural classifications, deliverable drugs, potential physiological barriers in drug delivery, strategies for overcoming these barriers, and future prospects.

Bioorthogonal Engineered Virus-Like Nanoparticles for Efficient Gene Therapy.

Gene therapy offers potentially transformative strategies for major human diseases. However, one of the key challenges in gene therapy is developing an effective strategy that could deliver genes into the specific tissue. Here, we report a novel virus-like nanoparticle, the bioorthgonal engineered virus-like recombinant biosome (reBiosome), for efficient gene therapies of cancer and inflammatory diseases. The mutant virus-like biosome (mBiosome) is first prepared by site-specific codon mutation for displaying 4-azido-L-phenylalanine on vesicular stomatitis virus glycoprotein of eBiosome at a rational site, and the reBiosome is then prepared by clicking weak acid-responsive hydrophilic polymer onto the mBiosome via bioorthogonal chemistry. The results show that the reBiosome exhibits reduced virus-like immunogenicity, prolonged blood circulation time and enhanced gene delivery efficiency to weakly acidic foci (like tumor and arthritic tissue). Furthermore, reBiosome demonstrates robust therapeutic efficacy in breast cancer and arthritis by delivering gene editing and silencing systems, respectively. In conclusion, this study develops a universal, safe and efficient platform for gene therapies for cancer and inflammatory diseases.

Regulating Stem Cell-Related Genes Induces the Plastic Differentiation of Cancer Stem Cells to Treat Breast Cancer.

Relapse of cancer is associated with multidirectional differentiation and unrestricted proliferative replication potential of cancer stem cells. Herein, we propose the plastic differentiation strategy for irreversible differentiation of cancer stem cells; further, salinomycin and its newly constructed functional liposomes are used to implement this strategy. Whole gene, cancer stem cell-related RNA, and protein expression analyses reveal that salinomycin induces the cancer stem cells into normal cells, dormant cells, and mature cancer cells. Besides, the results indicate that the gatekeeper is related to the inhibition of the protein kinase C (PKC) α signaling pathway. The differentiated normal or dormant cells are incorporated into normal tissue, whereas the rest are killed by chemotherapy. The findings would offer the evidence for plastic differentiation of cancer stem cells and propose a novel strategy for cancer therapy.

A Precise Nanostructure of Folate-Overhung Mitoxantrone DNA Tetrahedron for Targeted Capture Leukemia.

Regular chemotherapy cannot eliminate leukemic cells, due to the sparse distribution of cancer cells in leukemia patients. Here, we report a precise nanostructure of folate-overhung mitoxantrone DNA tetrahedron that enables the treatment of leukemic cells by targeted action. Folate is used as a targeting molecule and synthesized with DNA strand in forming the folate-overhang DNA complement, and the complement is then separately base-paired onto six sides of the fabricated DNA tetrahedron. Mitoxantrone is used as an anticancer agent and intercalated into the double strands of the folate-overhung DNA tetrahedron for drug loading. The evaluation studies are performed on leukemia BALL-1 and K562 cells. The results demonstrate that the folate-overhung mitoxantrone DNA tetrahedra (approximately 25 nm) are able to target leukemic cells, transport across the nuclei membrane, induce the apoptosis, and enhance the overall efficacy of treating leukemic cells in vitro and in leukemia-bearing mice. This study provides a potential drug-containing DNA nanostructure, to clean the sparsely distributed leukemic cells in patients.

Antioxidant Nanotherapies for the Treatment of Inflammatory Diseases.

Reactive oxygen species (ROS) are essential in regulating various physiological functions. However, overproduction of ROS is implicated in the pathogenesis of various inflammatory diseases. Antioxidant therapy has thus represented an effective strategy for the treatment of oxidative stress relevant inflammatory diseases. Conventional anti-oxidative agents showed limited in vivo effects owing to their non-specific distribution and low retention in disease sites. Over the past decades, significant achievements have been made in the development of antioxidant nanotherapies that exhibit multiple advantages such as excellent pharmacokinetics, stable anti-oxidative activity, and intrinsic ROS-scavenging properties. This review provides a comprehensive overview on recent advances in antioxidant nanotherapies, including ROS-scavenging inorganic nanoparticles, organic nanoparticles with intrinsic antioxidant activity, and drug-loaded anti-oxidant nanoparticles. We highlight the biomedical applications of antioxidant nanotherapies in the treatment of different inflammatory diseases, with an emphasis on inflammatory bowel disease, cardiovascular disease, and brain diseases. Current challenges and future perspectives to promote clinical translation of antioxidant nanotherapies are also briefly discussed.

Rational particle design to overcome pulmonary barriers for obstructive lung diseases therapy.

Pulmonary delivery of active drugs has been applied for the treatment of obstructive lung diseases, including asthma, chronic obstructive pulmonary disease and cystic fibrosis, for several decades and has achieved progress in symptom management by bronchodilator inhalation. However, substantial progress in anti-inflammation, prevention of airway remodeling and disease progression is limited, since the majority of the formulation strategies focus only on particle deposition, which is insufficient for pulmonary delivery of the drugs. The lack of knowledge on lung absorption barriers in obstructive lung diseases and on pathogenesis impedes the development of functional formulations by rational design. In this review, we describe the physiological structure and biological functions of the barriers in various regions of the lung, review the pathogenesis and functional changes of barriers in obstructive lung diseases, and examine the interaction of these barriers with particles to influence drug delivery efficiency. Subsequently, we review rational particle design for overcoming lung barriers based on excipients selection, particle size and surface properties, release properties and targeting ability. Additionally, useful particle fabrication strategies and commonly used drug carriers for pulmonary delivery in obstructive lung diseases are proposed in this article.

Nanosized functional miRNA liposomes and application in the treatment of TNBC by silencing Slug gene.

Background: Neo-adjuvant chemotherapy is an effective strategy for improving treatment of breast cancers. However, the efficacy of this treatment strategy is limited for treatment of triple negative breast cancer (TNBC). Gene therapy may be a more effective strategy for improving the prognosis of TNBC. Methods: A novel 25 nucleotide sense strand of miRNA was designed to treat TNBC by silencing the Slug gene, and encapsulated into DSPE-PEG2000-tLyp-1 peptide-modified functional liposomes. The efficacy of miRNA liposomes was evaluated on invasive TNBC cells and TNBC cancer-bearing nude mice. Furthermore, functional vinorelbine liposomes were constructed to investigate the anticancer effects of combined treatment. Results: The functional miRNA liposomes had a round shape and were nanosized (120 nm). Functional miRNA liposomes were effectively captured by TNBC cells in vitro and were target to mitochondria. Treatment with functional liposomes silenced the expression of Slug and Slug protein, inhibited the TGF-ß1/Smad pathway, and inhibited invasiveness and growth of TNBC cells. In TNBC cancer-bearing mice, functional miRNA liposomes exerted a stronger anticancer effect than functional vinorelbine liposomes, and combination therapy with these two formulations resulted in nearly complete inhibition of tumor growth. Preliminary safety evaluations indicated that the functional miRNA liposomes did not affect body weight or cause damage to any major organs. Furthermore, the functional liposomes significantly increased the half-life of the drug in the blood of cancer-bearing nude mice, and increased drug accumulation in breast cancer tissues. Conclusion: In this study, we constructed novel functional miRNA liposomes. These liposomes silenced Slug expression and inhibited the TGF-ß1/Smad pathway in TNBC cells, and enhanced anticancer efficacy in mice using combined chemotherapy. Hence, the present study demonstrated a promising strategy for gene therapy of invasive breast cancer.

Nanostructured SL9-CpG Lipovaccines Elicit Immune Response for the Treatment of Melanoma.

Antigen peptides and adjuvants have been extensively investigated for cancer immunotherapy, and they are expected to elicit specific immune responses for cancer treatment. However, the anti-cancer efficacy of antigen peptide and adjuvant-based cancer vaccines has been limited due to the inefficient delivery to draining lymph nodes after administration. Therefore, it is necessary to develop a suitable delivery system to transport antigen peptides and adjuvants. Here, we report a novel type of nanostructured lipovaccines for the treatment of melanoma by delivering antigen peptide (SL9) and oligodeoxynucleotide adjuvant (CpG) to the lymphatic vessels and to the draining lymph node. The SL9-CpG lipovaccines were characterized using dynamic laser scattering (DLS) and transmission electron microscopy (TEM). The lymph uptake, immune response elicitation and treatment effects were evaluated on melanoma-bearing C57BL/6 mice using flow cytometry (FCM), enzyme-linked immunosorbent assay (ELISA) and tumor inhibitory efficacy. The SL9-CpG lipovaccines were uniform with a nanoscale size (~70 nm), had high encapsulation efficiency, and exhibited effective lymph uptake, resulting in activation of specific cytotoxic CD8+ T cells, and release of IFN-γ, and a robust inhibition of tumor growth. Therefore, the nanostructured SL9-CpG lipovaccines offer a promising strategy for melanoma treatment.

Development of double strand RNA mPEI nanoparticles and application in treating invasive breast cancer.

Triple negative breast cancer (TNBC) has been characterized as a very heterogeneous subtype, and is more invasive and non-expressing of the genes for the estrogen receptor (ER), progesterone receptor (PR) and HER2/neu, with poor prognosis, and hence the efficacy of regular chemotherapy is very limited. Here, we report a kind of double strand RNA (dsRNA) mPEI nanoparticle for treatment of invasive TNBC. The studies were performed on TNBC cells in vitro and in TNBC cancer-bearing mice. The results showed that dsRNA mPEI nanoparticles were able to effectively transfect cells, and demonstrated a strong capability in knocking-down the Fra-1 gene and down-stream MMP-1 and MMP-9 genes in TNBC cells and TNBC cancer-bearing mice, thereby inhibiting the invasion and migration of cells. After intratumoral injection, dsRNA mPEI nanoparticles exhibited a robust anticancer efficacy in TNBC cancer-bearing mice, and the anticancer efficacy was superior to that of paclitaxel. In conclusion, dsRNA mPEI nanoparticles are able to effectively treat aggressive TNBC, and the mechanism studies reveal that they take effect by knocking-down Fra-1 relevant genes, hence interfering in transcription and translation of the genes, which are necessary for growth and metastasis of TNBC. Therefore, the present study offers a new and promising formulation and strategy for effective treatment of TNBC.

Functional chlorin gold nanorods enable to treat breast cancer by photothermal/photodynamic therapy.

BACKGROUND: The existing chemo/radiotherapy fail to eliminate cancer cells due to the restriction of either drug resistance or radio tolerance. The predicament urges researchers to continuously explore alternative strategy for achieving a potent curative effect. METHODS: Functional chlorin gold nanorods (Ce6-AuNR@SiO2-d-CPP) were fabricated aiming at treating breast cancer by photothermal/photodynamic therapy (PTT/PDT). The nanostructure was developed by synthesizing Au nanorods as the photothermal conversion material, and by coating the pegylated mesoporous SiO2 as the shell for entrapping photosensitizer Ce6 and for linking the D-type cell penetrating peptide (d-CPP). The function of Ce6-AuNR@SiO2-d-CPP was verified on human breast cancer MCF-7 cells and MCF-7 cells xenografts in nude mice. RESULTS: Under combinational treatment of PTT and PDT, Ce6-AuNR@SiO2-d-CPP demonstrated a strong cytotoxicity and apoptosis inducing effects in breast cancer cells in vitro, and a robust treatment efficacy in breast cancer-bearing nude mice. The uptake mechanism involved the energy-consuming caveolin-mediated endocytosis, and Ce6-AuNR@SiO2-d-CPP in PTT/PDT mode could induce apoptosis by multiple pathways in breast cancer cells. CONCLUSION: Ce6-AuNR@SiO2-d-CPP demonstrated a robust efficacy in the treatment of breast cancer by photothermal/photodynamic therapy. Therefore, the present study could offer a new promising strategy to treat the refractory breast cancer.

Nanostructured Dihydroartemisinin Plus Epirubicin Liposomes Enhance Treatment Efficacy of Breast Cancer by Inducing Autophagy and Apoptosis.

The heterogeneity of breast cancer and the development of drug resistance are the relapse reasons of disease after chemotherapy. To address this issue, a combined therapeutic strategy was developed by building the nanostructured dihydroartemisinin plus epirubicin liposomes. Investigations were performed on human breast cancer cells in vitro and xenografts in nude mice. The results indicated that dihydroartemisinin could significantly enhance the efficacy of epirubicin in killing different breast cancer cells in vitro and in vivo. We found that the combined use of dihydroartemisinin with epirubicin could efficiently inhibit the activity of Bcl-2, facilitate release of Beclin 1, and further activate Bax. Besides, Bax activated apoptosis which led to the type I programmed death of breast cancer cells while Beclin 1 initiated the excessive autophagy that resulted in the type II programmed death of breast cancer cells. In addition, the nanostructured dihydroartemisinin plus epirubicin liposomes prolonged circulation of drugs, and were beneficial for simultaneously delivering drugs into breast cancer tissues. Hence, the nanostructured dihydroartemisinin plus epirubicin liposomes could provide a new therapeutic strategy for treatment of breast cancer.

Development of functional docetaxel nanomicelles for treatment of brain glioma.

The efficacy of anticancer drugs is rather limited in the treatment of brain glioma due to the hindrance of the blood-brain barrier (BBB). Herein, we reported an easy formulation of functional docetaxel nanomicelles for the treatment of brain glioma using a graft copolymer soluplus as basic material through dual-modifications with a glucose-lipid derivative and a dequalinium-lipid derivative. The studies were performed on brain glioma U87MG cells, in vitro BBB models and brain glioma-bearing nude mice. The functional docetaxel nanomicelles were approximately 100 nm. The results demonstrated that the functional docetaxel nanomicelles could transport across the BBB, enhance the cellular uptake, target to the mitochondria, induce the apoptosis, increase the cytotoxicity in the brain glioma cells, and extend survival span of the brain glioma-bearing mice. The action mechanisms were associated with dual-modifications by the glucose-lipid derivative and the dequalinium-lipid derivative, both of which are beneficial for the transport across the BBB. Furthermore, the modification with dequalinium-lipid derivative was able to target to the brain glioma cells and to the mitochondria. In conclusion, the functional docetaxel nanomicelles would be a promising formulation for the treatment of brain glioma, deserving further development for clinical trials.

Fabrication of paclitaxel hybrid nanomicelles to treat resistant breast cancer via oral administration.

AIM: Oral chemotherapy using anticancer drugs would improve the clinical practice and the life quality of patients. The aim of the present study was to develop paclitaxel hybrid nanomicelles for oral administration to treat resistant breast cancer. METHODS: Evaluations were performed on human breast cancer MCF-7 cells, drug-resistant breast cancer MCF-7/Adr cells, and in MCF-7/Adr-xenografted BALB/c nude mice. The nanomicelles were composed of the polymer soluplus, d-α-tocopheryl polyethyleneglycol 1000 succinate (TPGS1000), and dequalinium (DQA). The constructed paclitaxel hybrid nanomicelles were ~65 nm in size. RESULTS: The nanomicelles improved cellular uptake and anticancer efficacy in the resistant breast cancer cells and induced mitochondria-mediated apoptosis. The mechanism of the apoptosis-inducing effect was related to the co-localization of the nanomicelles with mitochondria; the activation of pro-apoptotic protein Bax, cytochrome C, and apoptotic enzymes caspase 9 and 3; and the inhibition of anti-apoptotic proteins Bcl-2 and Mcl-1. Oral administration of paclitaxel hybrid nanomicelles had the same anticancer efficacy as the intravenous injection of taxol in resistant breast cancer-bearing mice. The oral suitability of this formulation was associated with the nanostructure and the actions of TPGS1000 and DQA. CONCLUSION: The fabricated paclitaxel hybrid nanomicelles could provide a promising oral formulation to treat drug-resistant breast cancer.

Efficacy in Treating Lung Metastasis of Invasive Breast Cancer with Functional Vincristine Plus Dasatinib Liposomes.

BACKGROUND: The metastasis of breast cancer is the leading cause of death, while lung metastasis is a major clinical phenomenon in patients with invasive breast cancer. The current treatment option comprising surgery, radiation, and standard chemotherapy cannot achieve a satisfactory effect on the treatment of lung metastasis of breast cancer. In this study, we report the potential of preventing lung metastasis of invasive breast cancer using the newly developed functional vincristine plus dasatinib liposomes. METHODS: The investigations were performed on invasive breast cancer MDA-MB-231 cells in vitro and in lung metastatic model of invasive breast cancer MDA-MB-231 cells in nude mice. RESULTS: The functional drug liposomes were able to induce cell cycle arrest at G2/M phase, induce apoptosis, inhibit adhesion, migration, and invasion of breast cancer cells in vitro, and prevent lung metastasis of breast cancer in nude mice. CONCLUSION: These findings indicate a potential clinical use of functional vincristine plus dasatinib liposomes for treating metastatic breast cancer.

Lipid vesicles containing transferrin receptor binding peptide TfR-T12 and octa-arginine conjugate stearyl-R8 efficiently treat brain glioma along with glioma stem cells.

Surgery and radiotherapy cannot fully remove brain glioma; thus, chemotherapy continues to play an important role in treatment of this illness. However, because of the restriction of the blood-brain barrier (BBB) and the regeneration of glioma stem cells, post-chemotherapy relapse usually occurs. Here, we report a potential solution to these issues that involves a type of novel multifunctional vinblastine liposomes equipped with transferrin receptor binding peptide TfR-T12 and octa-arginine conjugate stearyl-R8. Studies were performed on brain glioma and glioma stem cells in vitro and were verified in brain glioma-bearing mice. The liposomes were transported across the BBB, killing brain glioma and glioma stem cells via the induction of necrosis, apoptosis and autophagy. Furthermore, we reveal the molecular mechanisms for treating brain glioma and glioma stem cells via functionalized drug lipid vesicles.

The use of functional epirubicin liposomes to induce programmed death in refractory breast cancer.

Currently, chemotherapy is less efficient in controlling the continued development of breast cancer because it cannot eliminate extrinsic and intrinsic refractory cancers. In this study, mitochondria were modified by functional epirubicin liposomes to eliminate refractory cancers through initiation of an apoptosis cascade. The efficacy and mechanism of epirubicin liposomes were investigated on human breast cancer cells in vitro and in vivo using flow cytometry, confocal microscopy, high-content screening system, in vivo imaging system, and tumor inhibition in mice. Mechanistic studies revealed that the liposomes could target the mitochondria, activate the apoptotic enzymes caspase 8, 9, and 3, upregulate the proapoptotic protein Bax while downregulating the antiapoptotic protein Mcl-1, and induce the generation of reactive oxygen species (ROS) through an apoptosis cascade. In xenografted mice bearing breast cancer, the epirubicin liposomes demonstrated prolonged blood circulation, significantly increased accumulation in tumor tissue, and robust anticancer efficacy. This study demonstrated that functional epirubicin liposomes could significantly induce programmed death of refractory breast cancer by activating caspases and ROS-related apoptotic signaling pathways, in addition to the direct killing effect of the anticancer drug itself. Thus, we present a simple nanomedicine strategy to treat refractory breast cancer.

d-Retroenantiomer of Quorum-Sensing Peptide-Modified Polymeric Micelles for Brain Tumor-Targeted Drug Delivery.

Compared to that of other tumors, various barriers, such as the blood-brain barrier (BBB), enzymatic barriers, and the blood-brain tumor barrier, severely impede the successful treatment of gliomas. Peptide ligands were frequently used as targeting moieties to mediate brain tumor-targeted drug delivery. LWSW (SYPGWSW) is a recently reported quorum-sensing (QS) peptide that is able to efficiently cross the BBB. Even though linear LWSW traverses the BBB in vitro, its in vivo targeting ability has been greatly impaired due to proteolysis. Here, we developed a stable peptide, DWSW (DWDSDWDGDPDYDS), using the retro-inverso isomerization technique to achieve an enhanced antiglioma effect. In vitro studies have demonstrated that both the LWSW and DWSW peptides possessed excellent tumor-homing properties and barrier-penetration abilities, whereas DWSW exhibited exceptional stability in serum and maintained its targeting ability after serum preincubation. In vivo, DWSW-modified probes and micelles accumulated more efficiently in the glioma region in comparison with LWSW-modified probes and micelles because of full resistance to proteolysis in blood circulation. As expected, DWSW-modified paclitaxel (PTX)-loaded micelles (DWSW Micelle/PTX) exhibited the longest median survival time among glioma-bearing nude mice. Our results suggested that the QS peptide appears to be a promising targeting moiety, with potential applications in glioma-targeted drug delivery.

Dual-functional drug liposomes in treatment of resistant cancers.

Efficacy of regular chemotherapy is significantly hampered by multidrug resistance (MDR) and severe systemic toxicity. The reduced toxicity has been evidenced after administration of drug liposomes, consisting of the first generation of regular drug liposomes, the second generation of long-circulation drug liposomes, and the third generation of targeting drug liposomes. However, MDR of cancers remains as an unsolved issue. The objective of this article is to review the dual-functional drug liposomes, which demonstrate the potential in overcoming MDR. Herein, dual-functional drug liposomes are referring to the drug-containing phospholipid bilayer vesicles that possess a dual-function of providing the basic efficacy of drug and the extended effect of the drug carrier. They exhibit unique roles in treatment of resistant cancer via circumventing drug efflux caused by adenosine triphosphate binding cassette (ABC) transporters, eliminating cancer stem cells, destroying mitochondria, initiating apoptosis, regulating autophagy, destroying supply channels, utilizing microenvironment, and silencing genes of the resistant cancer. As the prospect of an estimation, dual-functional drug liposomes would exhibit more strength in their extended function, hence deserving further investigation for clinical validation.

C-type natriuretic peptide-modified lipid vesicles: fabrication and use for the treatment of brain glioma.

Chemotherapy of brain glioma faces a major obstacle owing to the inability of drug transport across the blood-brain barrier (BBB). Besides, neovasculatures in brain glioma site result in a rapid infiltration, making complete surgical removal virtually impossible. Herein, we reported a novel kind of C-type natriuretic peptide (CNP) modified vinorelbine lipid vesicles for transferring drug across the BBB, and for treating brain glioma along with disrupting neovasculatures. The studies were performed on brain glioma U87-MG cells in vitro and on glioma-bearing nude mice in vivo. The results showed that the CNP-modified vinorelbine lipid vesicles could transport vinorelbine across the BBB, kill the brain glioma, and destroy neovasculatures effectively. The above mechanisms could be associated with the following aspects, namely, long circulation in the blood; drug transport across the BBB via natriuretic peptide receptor B (NPRB)-mediated transcytosis; elimination of brain glioma cells and disruption of neovasculatures by targeting uptake and cytotoxic injury. Besides, CNP-modified vinorelbine lipid vesicles could induce apoptosis of the glioma cells. The mechanisms could be related to the activations of caspase 8, caspase 3, p53, and reactive oxygen species (ROS), and inhibition of survivin. Hence, CNP-modified lipid vesicles could be used as a carrier material for treating brain glioma and disabling glioma neovasculatures.