Hydrophobic penetrating peptide PFVYLI-modified stealth liposomes for doxorubicin delivery in breast cancer therapy

Melittin alcalase-hydrolysate: a novel chemically characterized multifunctional bioagent; antibacterial, anti-biofilm and anticancer

The prevalent life-threatening microbial and cancer diseases and lack of effective pharmaceutical therapies created the need for new molecules with antimicrobial and anticancer potential. Bee venom (BV) was collected from honeybee workers, and melittin (NM) was extracted from BV and analyzed by urea-polyacrylamide gel electrophoresis (urea-PAGE). The isolated melittin was hydrolyzed with alcalase into new bioactive peptides and evaluated for their antimicrobial and anticancer activity. Gel filtration chromatography fractionated melittin hydrolysate (HM) into three significant fractions (F1, F2, and F3), that were characterized by electrospray ionization mass spectrometry (ESI-MS) and evaluated for their antimicrobial, anti-biofilm, antitumor, and anti-migration activities. All the tested peptides showed antimicrobial and anti-biofilm activities against Gram-positive and Gram-negative bacteria. Melittin and its fractions significantly inhibited the proliferation of two types of cancer cells (Huh-7 and HCT 116). Yet, melittin and its fractions did not affect the viability of normal human lung Wi-38 cells. The IC50 and selectivity index data evidenced the superiority of melittin peptide fractions over intact melittin. Melittin enzymatic hydrolysate is a promising novel product with high potential as an antibacterial and anticancer agent.

Transdermal Properties of Cell-Penetrating Peptides: Applications and Skin Penetration Mechanisms

Cell-penetrating peptides (CPPs) consist of 5-30 amino acids with intracellular transduction abilities and diverse physicochemical properties, origins, and sequences. Although recent developments in bioinformatics have facilitated the prediction of CPP candidates with the potential for transduction into cells, the mechanisms by which CPPs penetrate cells and various tissues have not yet been elucidated at the molecular interaction level. Recently, the skin-penetrating ability of CPPs has gained wide attention and emerged as a simple and effective strategy for the delivery of macromolecules into the skin. Studies on the skin structure have suggested that the penetration potential of CPPs is based on the molecular interactions and characteristics of the lipid lamellar structure between corneocytes in the stratum corneum. This review provides a brief overview of the general properties, transduction mechanisms, applications, and safety issues of CPPs, focusing on CPPs with transdermal properties, that are currently being used to develop therapeutics and cosmetics.

Current perspectives and trends in nanoparticle drug delivery systems in breast cancer: bibliometric analysis and review

The treatment of breast cancer (BC) is a serious challenge due to its heterogeneous nature, multidrug resistance (MDR), and limited therapeutic options. Nanoparticle-based drug delivery systems (NDDSs) represent a promising tool for overcoming toxicity and chemotherapy drug resistance in BC treatment. No bibliometric studies have yet been published on the research landscape of NDDS-based treatment of BC. In this review, we extracted data from 1,752 articles on NDDS-based treatment of BC published between 2012 and 2022 from the Web of Science Core Collection (WOSCC) database. VOSviewer, CiteSpace, and some online platforms were used for bibliometric analysis and visualization. Publication trends were initially observed: in terms of geographical distribution, China and the United States had the most papers on this subject. The highest contributing institution was Sichuan University. In terms of authorship and co-cited authorship, the most prolific author was Yu Zhang. Furthermore, Qiang Zhang and co-workers have made tremendous achievements in the field of NDDS-based BC treatment. The article titled "Nanomedicine in cancer therapy: challenges, opportunities, and clinical applications" had the most citations. The Journal of Controlled Release was one of the most active publishers in the field. "Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries" was the most cited reference. We also analysed "hot" and cutting-edge research for NDDSs in BC treatment. There were nine topic clusters: "tumour microenvironment," "nanoparticles (drug delivery)," "breast cancer/triple-negative breast cancer," "combination therapy," "drug release (pathway)," "multidrug resistance," "recent advance," "targeted drug delivery", and "cancer nanomedicine." We also reviewed the core themes of research. In summary, this article reviewed the application of NDDSs in the treatment of BC.

Cell penetrating peptides: Highlighting points in cancer therapy

Cell-penetrating peptides (CPPs), first identified in HIV a few decades ago, deserved great attention in the last two decades; especially to support the penetration of anticancer drug means. In the drug delivery discipline, they have been involved in various approaches from mixing with hydrophobic drugs to the use of genetically conjugated proteins. The early classification as cationic and amphipathic CPPs has been extended to a few more classes such as hydrophobic and cyclic CPPs so far. Developing potential sequences utilized almost all methods of modern science: choosing high-efficiency peptides from natural protein sequences, sequence-based comparison, amino acid substitution, obtaining chemical and/or genetic conjugations, in silico approaches, in vitro analysis, animal experiments, etc. The bottleneck effect in this discipline reveals the complications that modern science faces in drug delivery research. Most CPP-based drug delivery systems (DDSs) efficiently inhibited tumor volume and weight in mice, but only in rare cases reduced their levels and continued further processes. The integration of chemical synthesis into the development of CPPs made a significant contribution and even reached the clinical stage as a diagnostic tool. But constrained efforts still face serious problems in overcoming biobarriers to reach further achievements. In this work, we reviewed the roles of CPPs in anticancer drug delivery, focusing on their amino acid composition and sequences. As the most suitable point, we relied on significant changes in tumor volume in mice resulting from CPPs. We provide a review of individual CPPs and/or their derivatives in a separate subsection.

A combination of a cell penetrating peptide and a protein translation inhibitor kills metastatic breast cancer cells

Cell Penetrating Peptides (CPPs) are promising anticancer and antimicrobial drugs. We recently reported that a peptide derived from the human mitochondrial/ER membrane-anchored NEET protein, Nutrient Autophagy Factor 1 (NAF-1; NAF-144-67), selectively permeates and kills human metastatic epithelial breast cancer cells (MDA-MB-231), but not control epithelial cells. As cancer cells alter their phenotype during growth and metastasis, we tested whether NAF-144-67 would also be efficient in killing other human epithelial breast cancer cells that may have a different phenotype. Here we report that NAF-144-67 is efficient in killing BT-549, Hs 578T, MDA-MB-436, and MDA-MB-453 breast cancer cells, but that MDA-MB-157 cells are resistant to it. Upon closer examination, we found that MDA-MB-157 cells display a high content of intracellular vesicles and cellular protrusions, compared to MDA-MB-231 cells, that could protect them from NAF-144-67. Inhibiting the formation of intracellular vesicles and dynamics of cellular protrusions of MDA-MB-157 cells, using a protein translation inhibitor (the antibiotic Cycloheximide), rendered these cells highly susceptible to NAF-144-67, suggesting that under certain conditions, the killing effect of CPPs could be augmented when they are applied in combination with an antibiotic or chemotherapy agent. These findings could prove important for the treatment of metastatic cancers with CPPs and/or treatment combinations that include CPPs.

Development of Novel Paclitaxel-Loaded ZIF-8 Metal-Organic Framework Nanoparticles Modified with Peptide Dimers and an Evaluation of Its Inhibitory Effect against Prostate Cancer Cells

Prostate cancer (PC) is one of the common malignant tumors of the male genitourinary system. Here, we constructed PTX@ZIF-8, which is a metal-organic-framework-encapsulated drug delivery nanoparticle with paclitaxel (PTX) as a model drug, and further modified the synthesized peptide dimer (Di-PEG₂₀₀₀-COOH) onto the surface of PTX@ZIF-8 to prepare a nanotargeted drug delivery system (Di-PEG@PTX@ZIF-8) for the treatment of prostate cancer. This study investigated the morphology, particle size distribution, zeta potential, drug loading, encapsulation rate, stability, in vitro release behavior, and cytotoxicity of this targeted drug delivery system, and explored the uptake of Di-PEG@PTX@ZIF-8 by human prostate cancer Lncap cells at the in vitro cellular level, as well as the proliferation inhibition and promotion of apoptosis of Lncap cells by the composite nanoparticles. The results suggest that Di-PEG@PTX@ZIF-8, as a zeolitic imidazolate frameworks-8-loaded paclitaxel nanoparticle, has promising potential for the treatment of prostate cancer, which may provide a novel strategy for the delivery system targeting prostate cancer.

Smart Chondroitin Sulfate Micelles for Effective Targeted Delivery of Doxorubicin Against Breast Cancer Metastasis

Introduction

Metastasis is a major challenge in breast cancer therapy. The successful chemotherapy of breast cancer largely depends on the ability to block the metastatic process. Herein, we designed a dual-targeting and stimuli-responsive drug delivery system for targeted drug delivery against breast cancer metastasis.

Methods

AS1411 aptamer-modified chondroitin sulfate A-ss-deoxycholic acid (ACSSD) was synthesized, and the unmodified CSSD was used as the control. Chemotherapeutic drug doxorubicin (DOX)-containing ACSSD (D-ACSSD) micelles were prepared by a dialysis method. The ACSSD conjugate was confirmed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), dynamic light scattering (DLS), and transmission electron microscopy (TEM). In vitro cellular uptake and cytotoxicity of D-ACSSD micelles were studied by confocal laser scanning microscopy (CLSM) and MTT assay in breast tumor cells. The inhibition capability of D-ACSSD micelles in cell migration and invasion was carried out in 4T1 cells. In vivo antitumor activity of DOX-containing micelles was investigated in metastatic 4T1-bearing Balb/c mice.

Results

D-ACSSD and DOX-loaded CSSD (D-CSSD) micelles exhibited high drug encapsulation content and reduction-responsive characteristics. D-ACSSD micelles were spherical in shape. Compared with D-CSSD, D-ACSSD showed higher cellular uptake and more potent killing activity in 4T1 and MDA-MB-231 cells. Additionally, D-ACSSD exhibited stronger inhibitory effects on the invasion and migration of highly metastatic 4T1 cells than unmodified D-CSSD. Among the DOX-containing formulations, D-ACSSD micelles presented the most effective inhibition of tumor growth and lung metastasis in orthotopic 4T1-bearing mice in vivo. It also revealed that ACSSD micelles did not exhibit obvious systemic toxicity.

Conclusion

The smart D-ACSSD micelles could be a promising delivery system for the therapy of metastatic breast cancer.

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.

Lipid-Based Nanomaterials for Drug Delivery Systems in Breast Cancer Therapy

Globally, breast cancer is one of the most prevalent diseases, inducing critical intimidation to human health. Lipid-based nanomaterials have been successfully demonstrated as drug carriers for breast cancer treatment. To date, the development of a better drug delivery system based on lipid nanomaterials is still urgent to make the treatment and diagnosis easily accessible to breast cancer patients. In a drug delivery system, lipid nanomaterials have revealed distinctive features, including high biocompatibility and efficient drug delivery. Specifically, a targeted drug delivery system based on lipid nanomaterials has inherited the advantage of optimum dosage and low side effects. In this review, insights on currently used potential lipid-based nanomaterials are collected and introduced. The review sheds light on conjugation, targeting, diagnosis, treatment, and clinical significance of lipid-based nanomaterials to treat breast cancer. Furthermore, a brighter side of lipid-based nanomaterials as future potential drug delivery systems for breast cancer therapy is discussed.

2D MOF Nanosensor-Integrated Digital Droplet Microfluidic Flow Cytometry for In Situ Detection of Multiple miRNAs in Single CTC Cells

Current circulating tumor cells (CTCs) detection strategies based on surface epithelial markers suffer from low specificity in distinguishing between CTCs and epithelial cells in hematopoietic cell population. Tumor-associated miRNAs within CTCs are emerging as new biomarkers due to their high correlation with tumor development and progress. However, in-situ simultaneous analysis of multiple miRNAs in single CTC cell is still challenging. To overcome this limitation, a digital droplet microfluidic flow cytometry based on biofunctionalized 2D metal-organic framework nanosensor (Nano-DMFC) is developed for in situ detection of dual miRNAs simultaneously in single living breast cancer cells. Here, 2D MOF-based fluorescent resonance energy transfer (FRET) nanosensors are established by conjugating dual-color fluorescence dye-labeled DNA probes on MOF nanosheet surface. In the Nano-DMFC, 2D MOF-based nanoprobes are precisely microinjected into each single-cell encapsulated droplets to achieve dual miRNA characterization in single cancer cell. This Nano-DMFC platform successfully detects dual miRNAs at single-cell resolution in 10 mixed positive MCF-7 cells out of 10 000 negative epithelial cells in serum biomimic samples. Moreover, this Nano-DMFC platform shows good reproductivity in the recovery experiment of spiked blood samples, which demonstrate the high potential for CTC-based cancer early diagnosis and prognosis.

Recent applications of cell-penetrating peptide guidance of nanosystems in breast and prostate cancer (Review)

Cell-penetrating peptides (CPPs) are small peptides from natural sources or designed from other protein sequences that can penetrate cell membranes. This property has been used in biomedicine to add them to biomolecules to improve their capacity for cell internalization and as a guidance tool for specific cell types. CPPs have been shown to enhance cellular uptake in vitro and in vivo, improving the efficacy of anticancer drugs such as doxorubicin and paclitaxel, while also limiting their cytotoxic effects on healthy cells and tissues. The current study reviews the internalization and major therapeutic results achieved from the functionalization of nanosystems with CPPs for guidance into breast and prostate cancer cells in vitro and in vivo. In addition, the practical results obtained are specifically discussed for use as a starting point for scientists looking to begin research in this field.

Development of Anticancer Peptides with Low Hemolysis, High Penetrating Membrane Activity, Certain Analgesic Activity and the Synergistic Anticancer Effect

Herein, an amphiphilic cationic α-helical anticancer lipopeptide P10 with the low toxicity and high penetrating membrane activity was developed. The lipopeptide could self-assemble into stable spherical aggregates in aqueous solution,...

Evaluation of nanoscaled dual targeting drug-loaded liposomes on inhibiting vasculogenic mimicry channels of brain glioma

Brain glioma is the most common primary tumour of the central nervous system. Complete surgical removal of the brain glioma is virtually impossible. Chemotherapy is still an important treatment for brain glioma. However, blood-brain barrier (BBB) and vasculogenic mimicry (VM) channels remain two hindrances in regular treatments. Herein, we developed a novel nanoscaled dual targeting daunorubicin plus rofecoxib liposomes which could transport across the BBB, and eliminate brain glioma cells along with the VM channels. The liposomes were modified with two functional materials, and showed round in shape with a diameter about 120 nm. Evaluations were performed on human brain glioma U87MG cells in vitro and on intracranial brain glioma-bearing nude mice. The dual targeting liposomes demonstrated a long circulatory effect in the blood system, were able to transport across the BBB, and were accumulated into the brain. The results indicated that the dual targeting daunorubicin plus rofecoxib liposomes could inhibit the brain glioma VM channels and exhibited a significant efficacy in the treatment of intracranial glioma-bearing nude mice. The mechanisms are related to down regulations MMP-2, MMP-9, FAK and HIF-α. Hence, the established dual targeting liposomes could be a potential formulation to treat the brain glioma along with eliminating VM channels.

Efficient Anti-Glioma Therapy Through the Brain-Targeted RVG15-Modified Liposomes Loading Paclitaxel-Cholesterol Complex

Background

Glioma is the most common primary malignant brain tumor with a dreadful overall survival and high mortality. One of the most difficult challenges in clinical treatment is that most drugs hardly pass through the blood–brain barrier (BBB) and achieve efficient accumulation at tumor sites. Thus, to circumvent this hurdle, developing an effectively traversing BBB drug delivery nanovehicle is of significant clinical importance. Rabies virus glycoprotein (RVG) is a derivative peptide that can specifically bind to nicotinic acetylcholine receptor (nAChR) widely overexpressed on BBB and glioma cells for the invasion of rabies virus into the brain. Inspired by this, RVG has been demonstrated to potentiate drugs across the BBB, promote the permeability, and further enhance drug tumor-specific selectivity and penetration.

Methods

Here, we used the RVG15, rescreened from the well-known RVG29, to develop a brain-targeted liposome (RVG15-Lipo) for enhanced BBB permeability and tumor-specific delivery of paclitaxel (PTX). The paclitaxel-cholesterol complex (PTX-CHO) was prepared and then actively loaded into liposomes to acquire high entrapment efficiency (EE) and fine stability. Meanwhile, physicochemical properties, in vitro and in vivo delivery efficiency and therapeutic effect were investigated thoroughly.

Results

The particle size and zeta potential of PTX-CHO-RVG15-Lipo were 128.15 ± 1.63 nm and −15.55 ± 0.78 mV, respectively. Compared with free PTX, PTX-CHO-RVG15-Lipo exhibited excellent targeting efficiency and safety in HBMEC and C6 cells, and better transport efficiency across the BBB in vitro model. Furthermore, PTX-CHO-RVG15-Lipo could noticeably improve the accumulation of PTX in the brain, and then promote the chemotherapeutic drugs penetration in C6^luc orthotopic glioma based on in vivo imaging assays. The in vivo antitumor results indicated that PTX-CHO-RVG15-Lipo significantly inhibited glioma growth and metabasis, therefore improved survival rate of tumor-bearing mice with little adverse effect.

Conclusion

Our study demonstrated that the RVG15 was a promising brain-targeted specific ligands owing to the superior BBB penetration and tumor targeting ability. Based on the outstanding therapeutic effect both in vitro and in vivo, PTX-CHO-RVG15-Lipo was proved to be a potential delivery system for PTX to treat glioma in clinic.

Amyloid-like Self-Assembly of a Hydrophobic Cell-Penetrating Peptide and Its Use as a Carrier for Nucleic Acids

Cell-penetrating peptides (CPPs) are a topical subject potentially exploitable for creating nanotherapeutics for the delivery of bioactive loads. These compounds are often classified into three major categories according to their physicochemical characteristics: cationic, amphiphilic, and hydrophobic. Among them, the group of hydrophobic CPPs has received increasing attention in recent years due to toxicity concerns posed by highly cationic CPPs. The hexapeptide PFVYLI (P, proline; F, phenylalanine; V, valine; Y, tyrosine; L, leucine; and I, isoleucine), a fragment derived from the C-terminal portion of α1-antitrypsin, is a prototypal example of hydrophobic CPP. This sequence shows reduced cytotoxicity and a capacity of nuclear localization, and its small size readily hints at its suitability as a building block to construct nanostructured materials. In this study, we examine the self-assembling properties of PFVYLI and investigate its ability to form noncovalent complexes with nucleic acids. By using a combination of biophysical tools including synchrotron small-angle X-ray scattering and atomic force microscopy-based infrared spectroscopy, we discovered that this CPP self-assembles into discrete nanofibrils with remarkable amyloidogenic features. Over the course of days, these fibrils coalesce into rodlike crystals that easily reach the micrometer range. Despite lacking cationic residues in the composition, PFVYLI forms noncovalent complexes with nucleic acids that retain β-sheet pairing found in amyloid aggregates. In vitro vectorization experiments performed with double-stranded DNA fragments indicate that complexes promote the internalization of nucleic acids, revealing that tropism toward cell membranes is preserved upon complexation. On the other hand, transfection assays with splice-correction oligonucleotides (SCOs) for luciferase expression show limited bioactivity across a narrow concentration window, suggesting that the propensity to form amyloidogenic aggregates may trigger endosomal entrapment. We anticipate that the findings presented here open perspectives for using this archetypical hydrophobic CPP in the fabrication of nanostructured scaffolds, which potentially integrate properties of amyloids and translocation capabilities of CPPs.

Construction and evaluation of novel αvβ3 integrin ligand-conjugated ultrasmall star polymer micelles targeted glomerular podocytes through GFB permeation

As glomerular cells, podocytes are the last line of defense for glomerular filtration barriers (GFB) and play a critical role in chronic kidney disease (CKD). Podocyte-targeted drug delivery is a promising direction in the treatment of CKD. In this study, we constructed four-arm star polymers conjugated with a novel linear RWrNM peptide. And poly ε-caprolactone (PCL) hydrophobic core and brush poly (2-hydroxyethyl methacrylate) (PHEMA) hydrophilic shell were synthesized by ROP and SET LRP polymerization. The PHEMA modified by succinic anhydride was coupled with the novel linear RWrNM peptide, and then the PCL hydrophobic core was loaded with dexamethasone acetate (Dexac) to form micelles with stable dimensions. Our findings showed that the novel micelles had an ultrasmall particle size of 16-30 nm. We, for the first time, showed that the specific affinity of the novel linear RWrNM peptide to primary podocytes (24.9 ± 1.7 times of the free RhB uptake) through the αvβ3 integrin receptor mediation was comparable to that of B16F10 cells (24.4 ± 1.2 times of the free RhB uptake). In vivo studies showed that the novel ultrasmall micelles possessed a significant kidney-targeted effect, excellent podocyte colocalization effect, and GFB permeability at 49%-60 % in normal SD rats. Besides, the novel ultrasmall micelles decreased the plasma elimination half-life of Dexac to 1.62-2.09 h and showed good safety in vitro and in vivo. Both in vitro and in vivo results demonstrated the novel ultrasmall micelles could be used as a promising drug delivery strategy for actively targeted therapy of CKD.

Recent advances in drug delivery systems for enhancing drug penetration into tumors

The emergence of nanomaterials for drug delivery provides the opportunity to avoid the side effects of systemic drug administration and injury caused by the removal of tumors, delivering great promise for future cancer treatments. However, the efficacy of current nano drugs is not significantly better than that of the original drug treatments. The important reason is that nano drugs enter the tumor vasculature, remaining close to the blood vessels and unable to enter the tumor tissue or tumor cells to complete the drug delivery process. The low efficiency of drug penetration into tumors has become a bottleneck restricting the development of nano-drugs. Herein, we present a systematic overview of recent advances on the design of nano-drug carriers in drug delivery systems for enhancing drug penetration into tumors. The review is organized into four sections: The drug penetration process in tumor tissue includes paracellular and transcellular transport, which is summarized first. Strategies that promote tumor penetration are then introduced, including methods of remodeling the tumor microenvironment, charge inversion, dimensional change, and surface modification of ligands which promote tissue penetration. Conclusion and the prospects for the future development of drug penetration are finally briefly illustrated. The review is intended to provide thoughts for effective treatment of cancer by summarizing strategies for promoting the endocytosis of nano drugs into tumor cells.

Cyano Derivatives of 7-Aminoquinoline That Are Highly Emissive in Water: Potential for Sensing Applications

6-Cyano-7-aminoquinoline (6CN-7AQ) and 3-cyano-7-aminoquinoline (3CN-7AQ) were synthesized and found to exhibit intense emission with quantum yield as high as 63 % and 85 %, respectively, in water. Conversely, their derivatives 6-cyano-7-azidoquinoline (6CN-7N₃ Q) and 3-cyano-7-azidoquinoline (3CN-7N₃ Q) show virtually no emission, which makes them suitable to be used as recognition agents in azide reactions based on fluorescence recovery. Moreover, conjugation of 6CN-7AQ with a hydrophobic biomembrane-penetration peptide PFVYLI renders a nearly non-emissive 6CN-7AQ-PFVYLI composite, which can be digested by proteinase K, recovering the highly emissive 6CN-7AQ with ∼200-fold enhancement. The result provides an effective early confirmation for RT-qPCR in viral detection.

Surface Plasmon Resonance as a Characterization Tool for Lipid Nanoparticles Used in Drug Delivery

The development of drug carriers based in lipid nanoparticles (LNPs) aims toward the synthesis of non-toxic multifunctional nanovehicles that can bypass the immune system and allow specific site targeting, controlled release and complete degradation of the carrier components. Among label free techniques, Surface Plasmon Resonance (SPR) biosensing is a versatile tool to study LNPs in the field of nanotherapeutics research. SPR, widely used for the analysis of molecular interactions, is based on the immobilization of one of the interacting partners to the sensor surface, which can be easily achieved in the case of LNPs by hydrophobic attachment onto commercial lipid- capture sensor chips. In the last years SPR technology has emerged as an interesting strategy for studying molecular aspects of drug delivery that determines the efficacy of the nanotherapeutical such as LNPs' interactions with biological targets, with serum proteins and with tumor extracelullar matrix. Moreover, SPR has contributed to the obtention and characterization of LNPs, gathering information about the interplay between components of the formulations, their response to organic molecules and, more recently, the quantification and molecular characterization of exosomes. By the combination of available sensor platforms, assay quickness and straight forward platform adaptation for new carrier systems, SPR is becoming a high throughput technique for LNPs' characterization and analysis.

Inhibition of growth and metastasis of breast cancer by targeted delivery of 17-hydroxy-jolkinolide B via hyaluronic acid-coated liposomes

Hyaluronic acid (HA)-coated liposomes were designed for the targeted delivery of 17-hydroxy-jolkinolide B (HA-Lip-HJB). HA-Lip-HJB had a particle size of 130.8 ± 1.9 nm, zeta potential of -52.36 ± 1.91 mV, and encapsulation efficiency of 89.2 ± 1.5 %. In vitro cell experiments indicated that modification of HA-Lip-HJB increased its cytotoxicity and cellular uptake via CD44 receptor-mediated endocytosis pathway. Of particular importance is that HA-Lip-HJB suppressed cell migration and invasion by inhibiting epithelial-mesenchymal transition (EMT) process. Moreover, the HA-Lip-HJB displayed notable growth inhibition on tumor spheroids. Furthermore, in vivo tissue distribution and anti-tumor experiments carried on BALB/C mice bearing 4T1 tumor indicated that HA-Lip-HJB had strong tumor targeting and tumor suppression abilities. The results also demonstrated that HA-Lip-HJB inhibited tumor cells migration and colonization on the lung. Therefore, HA-Lip-HJB is a promising formulation for metastatic breast cancer therapy.

Pharmacokinetics of inhaled nanotherapeutics for pulmonary delivery

Pulmonary delivery of lipid-based nanotherapeutics by inhalation presents an advantageous alternative to oral and intravenous routes of administration that avoids enzymatic degradation in gastrointestinal tract and hepatic first pass metabolism and also limits off-target adverse side effects upon heathy tissues. For lung-related indications, inhalation provides localized delivery in order to enhance therapeutic efficacy at the site of action. Optimization of physicochemical properties, selected drug and inhalation format can greatly influence the pharmacokinetic behavior of inhaled nanoparticle systems and their payloads. The present review analyzes a wide range of nanoparticle systems, their formulations and consequent effect on pharmacokinetic distribution of delivered active components after inhalation.

Dual-Modified Liposome for Targeted and Enhanced Gene Delivery into Mice Brain

The development of neuropharmaceutical gene delivery systems requires strategies to obtain efficient and effective brain targeting as well as blood-brain barrier (BBB) permeability. A brain-targeted gene delivery system based on a transferrin (Tf) and cell-penetrating peptide (CPP) dual-functionalized liposome, CPP-Tf-liposome, was designed and investigated for crossing BBB and permeating into the brain. We selected three sequences of CPPs [melittin, Kaposi fibroblast growth factor (kFGF), and penetration accelerating sequence-R8] and compared their ability to internalize into the cells and, subsequently, improve the transfection efficiency. Study of intracellular uptake indicated that liposomal penetration into bEnd.3 cells, primary astrocytes, and primary neurons occurred through multiple endocytosis pathways and surface modification with Tf and CPP enhanced the transfection efficiency of the nanoparticles. A coculture in vitro BBB model reproducing the in vivo anatomophysiological complexity of the biologic barrier was developed to characterize the penetrating properties of these designed liposomes. The dual-functionalized liposomes effectively crossed the in vitro barrier model followed by transfecting primary neurons. Liposome tissue distribution in vivo indicated superior ability of kFGF-Tf-liposomes to overcome BBB and reach brain of the mice after single intravenous administration. These findings demonstrate the feasibility of using strategically designed liposomes by combining Tf receptor targeting with enhanced cell penetration as a potential brain gene delivery vector. SIGNIFICANCE STATEMENT: Rational synthesis of efficient brain-targeted gene carrier included modification of liposomes with a target-specific ligand, transferrin, and with cell-penetrating peptide to enhance cellular internalization. Our study used an in vitro triple coculture blood-brain barrier (BBB) model as a tool to characterize the permeability across BBB and functionality of designed liposomes prior to in vivo biodistribution studies. Our study demonstrated that rational design and characterization of BBB permeability are efficient strategies for development of brain-targeted gene carriers.

In vitro and in vivo characterization of CPP and transferrin modified liposomes encapsulating pDNA

The limitations imposed on brain therapy by the blood-brain barrier (BBB) have warranted the development of carriers that can overcome and deliver therapeutic agents into the brain. We strategically designed liposomal nanoparticles encasing plasmid DNA for efficient transfection and translocation across the in vitro BBB model as well as in vivo brain-targeted delivery. Liposomes were surface modified with two ligands, cell-penetrating peptide (PFVYLI or R9F2) for enhanced internalization into cells and transferrin (Tf) ligand for targeting transferrin-receptor expressed on brain capillary endothelial cells. Dual-modified liposomes encapsulating pDNA demonstrated significantly (P < 0.05) higher in vitro transfection efficiency compared to single-modified nanoparticles. R9F2Tf-liposomes showed superior ability to cross in vitro BBB and, subsequently, transfect primary neurons. Additionally, these nanoparticles crossed in vivo BBB and reached brain parenchyma of mice (6.6%) without causing tissue damage. Transferrin receptor-targeting with enhanced cell penetration is a relevant strategy for efficient brain-targeted delivery of genes.

Enhanced antitumour efficacy of functionalized doxorubicin plus schisandrin B co-delivery liposomes via inhibiting epithelial-mesenchymal transition

Non-small cell lung cancer (NSCLC) is a malignant cancer characterized by easy invasion, metastasis and poor prognosis, so that conventional chemotherapy cannot inhibit its invasion and metastasis. Doxorubicin (DOX), as a broad-spectrum antitumour drug, cannot be widely used in clinic because of its poor targeting, short half-life, strong toxicity and side effects. Therefore, the aim of our study is to construct a kind of PFV modified DOX plus schisandrin B liposomes to solve the above problems, and to explore its potential mechanism of inhibiting NSCLC invasion and metastasis. The antitumour efficiency of the targeting liposomes was carried out by cytotoxicity, heating ablation, wound healing, transwell, vasculogenic mimicry channels formation and metastasis-related protein tests in vitro. Pharmacodynamics were evaluated by tumour inhibition rate, HE staining and TUNEL test in vivo. The enhanced anti-metastatic mechanism of the targeting liposomes was attributed to the downregulation of vimentin, vascular endothelial growth factor, matrix metalloproteinase 9 and upregulation of E-cadherin. In conclusion, the PFV modified DOX plus schisandrin B liposomes prepared in this study provided a treatment strategy with high efficiency for NSCLC.

Enhanced antitumor efficacy using epirubicin and schisandrin B co-delivery liposomes modified with PFV via inhibiting tumor metastasis

As a malignant tumor, breast cancer is very prone to metastasis. Chemotherapy is one of the most common means for treating breast cancer. However, due to the serious metastasis and the poor targeting effect of traditional chemotherapeutic drugs, even after years of efforts, the therapeutic effect is still unsatisfied. Therefore, in this study, we constructed a kind of PFV modified epirubicin plus schisandrin B liposomes to solve the above disadvantages. In vitro experiments showed that the targeting liposomes with ideal physicochemical property could increase the cytotoxicity of MDA-MB-435S cells, destroy the formation of vasculogenic mimicry (VM), and inhibit tumor invasion and migration. Action mechanisms indicated that the inhibition of targeting liposomes on tumor metastasis was attributed to the regulation of the expression of vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9), vimentin (VIM), and E-cadherin (E-cad). In vivo pharmacodynamic experiments showed that the targeting liposomes could significantly improve the antitumor effect in mice. H&E staining and TUNEL results showed that the targeting liposomes could promote the apoptosis of tumor cells. Hence, the PFV modified epirubicin plus schisandrin B liposomes constructed in this study provided a new therapeutic strategy for breast cancer.

Efficient neuronal targeting and transfection using RVG and transferrin-conjugated liposomes

Effective transport of therapeutic nucleic acid to brain has been a challenge for the success of gene therapy for treating brain diseases. In this study, we proposed liposomal nanoparticles modified with brain targeting ligandsfor active brain targeting with enhanced BBB permeation and delivery of genes to brain. We targeted transferrin and nicotinic acetylcholine receptors by conjugating transferrin (Tf) and rabies virus glycoprotein (RVG) peptide to surface of liposomes. Liposomal formulations showed homogeneous particle size and ability to protect plasmid DNA against enzymatic degradation. These nanoparticles were internalized by brain endothelial cells, astrocytes and primary neuronal cells through energy-dependent endocytosis pathways. RVG-Tf coupled liposomes showed superior ability to transfect cells compared to liposomes without surface modification or single modification. Characterization of permeability through blood brain barrier (BBB) and functionality of designed liposomes were performed using an in vitro triple co-culture BBB model. Liposome-RVG-Tf efficiently translocated across in vitro BBB model and, consecutively, transfected primary neuronal cells. Notably, brain-targeted liposomes promoted in vivo BBB permeation. These studies suggest that modifications of liposomes with brain-targeting ligands are a promising strategy for delivery of genes to brain.

cRGDfK-Grafted Small-Size Quercetin Micelles For Enhancing Therapy Efficacy Of Active Ingredient From The Chinese Medicinal Herb

Background

As an active ingredient of Chinese herbal medicine, quercetin (QU) can significantly induce apoptosis of tumor cells and give play to other effect such as decreasing both fibroblast population and collagen in cancer cell nest. However, the antitumor efficacy of quercetin was mostly evaluated at cellular level and rarely developed in vivo by intravenous injection, which may be ascribed to its inferior physicochemical properties including water insolubility, short plasma half-time, and insufficient enrichment in the tumor tissues.

Methods

The DSPE-PEG was used to construct quercetin-loaded micelles, and the integrin ligand cRGDfK was grafted to modify the nanocarrier for enhancing its cancer-specific homing. The MALDI-TOF-MS, DLS, TEM, and UV were orderly operated to characterize guidance molecules and micelles by morphology, size distribution, Zeta potential, and drug encapsulation efficiency. In addition, the surface plasmon resonance study and real-time confocal analysis were employed to demonstrate α_vβ₃ integrin-overexpressing B16 cells-specific binding and uptake. After further pharmacodynamics studies in vitro and in vivo, we also evaluate systemic toxicity about cRGDfK-PM-QU.

Results

The cRGDfK was successfully stitched with DSPE-PEG and modified on the surface of micelles. The ligand modification enhanced the negative charges of the micelles, but it did not induce significant changes in particle size. The quercetin micelles were about 15 nm in size and negatively charged, and had spherical morphology and high drug encapsulation efficiency. In vitro, the cRGDfK-modified micelles (cRGDfK-PM) showed α_vβ₃ integrin-overexpressing B16 cells-specific binding and uptake, and cRGDfK-PM-QU (QU loaded in cRGDfK-PM) induced more significant cell apoptosis and cytotoxic effects against B16 tumor cells than counterpart micelles (PM-QU). In vivo, the cRDGfK modification enhanced enrichment in B16 tumor tissue, improved the therapeutic efficacy of the quercetin-loaded micelles against B16 tumor, and exhibited lower systemic and pulmonary toxicity compared with counterpart micelles in the mouse mode.

Conclusion

Quercetin as a natural product has triggered increasing interest in the antitumor field. In this study, cRGDfK-modified DSPE-PEG micelles significantly optimized quercetin therapeutic efficacy and pulmonary toxicity as well as lowered systemic toxicity.

Development and screening of brain-targeted lipid-based nanoparticles with enhanced cell penetration and gene delivery properties

Background

The potential of gene therapy for treatment of neurological disorders can be explored using designed lipid-based nanoparticles such as liposomes, which have demonstrated ability to deliver nucleic acid to brain cells. We synthesized liposomes conjugated to cell-penetrating peptides (CPPs) (vascular endothelial-cadherin-derived peptide [pVec], pentapeptide QLPVM and HIV-1 trans-activating protein [TAT]) and transferrin (Tf) ligand, and examined the influence of surface modifications on the liposome delivery capacity and transfection efficiency of encapsulated plasmid DNA. The design of liposomes was based on targeting molecular recognition of transferrin receptor overexpressed on the blood–brain barrier (BBB) with enhanced internalization ability of CPPs.

Methods

CPP-Tf-liposomes were characterized by particle size distribution, zeta potential, protection of encapsulated plasmid DNA, uptake mechanisms and transfection efficiencies. An in vitro triple co-culture BBB model selected the liposomal formulations that were able to cross the in vitro BBB and subsequently, transfect primary neuronal cells. The in vivo biodistribution and biocompatibility of selected formulations were also investigated in mice.

Results

Liposomal formulations were able to protect the encapsulated plasmid DNA against enzymatic degradation and presented low hemolytic potential and low cytotoxicity at 100 nM phospholipid concentration. Cellular internalization of nanoparticles occurred via multiple endocytosis pathways. CPP-Tf-conjugated liposomes mediated robust transfection of brain endothelial (bEnd.3), primary glial and primary neuronal cells. Liposomes modified with Tf and TAT demonstrated superior ability to cross the barrier layer and subsequently, transfect neuronal cells compared to other formulations. Quantification of fluorescently labeled liposomes and in vivo imaging demonstrated that this system could efficiently overcome the BBB and penetrate the brain of mice (7.7% penetration of injected dose).

Conclusion

In vitro screening platforms are important tools to enhance the success of brain-targeted gene delivery systems. The potential of TAT-Tf-liposomes as efficient brain-targeted gene carriers in vitro and in vivo was suggested to be related to the presence of selected moieties on the nanoparticle surface.

DSPE-PEG Modification of α-Conotoxin TxID

In order to improve stability of a peptide marine drug lead, α-conotoxin TxID, we synthesized and modified TxID at the N-terminal with DSPE-PEG-NHS by a nucleophilic substitution reaction to prepare the DSPE-PEG-TxID for the first time. The reaction conditions, including solvent, ratio, pH, and reaction time, were optimized systematically and the optimal one was reacted in dimethyl formamide at pH 8.2 with triethylamine at room temperature for 120 h. The in vitro stabilities in serum, simulated gastric juice, and intestinal fluid were tested, and improved dramatically compared with TxID. The PEG-modified peptide was functionally tested on α3β4 nicotinic acetylcholine receptor (nAChR) heterologously expressed in Xenopus laevis oocytes. The DSPE-PEG-TxID showed an obvious inhibition effect on α3β4 nAChR. All in all, the PEG modification of TxID was improved in stability, resistance to enzymatic degradation, and may prolong the half-life in vivo, which may pave the way for the future application in smoking cessation and drug rehabilitation, as well as small cell lung cancer.

Inhibition of tumor metastasis by targeted daunorubicin and dioscin codelivery liposomes modified with PFV for the treatment of non-small-cell lung cancer

Background: Chemotherapy for non-small-cell lung cancer (NSCLC) still leads to unsatisfactory clinical prognosis because of poor active targeting and tumor metastasis. Purpose: The objective of this study was to construct a kind of PFV peptide modified targeted daunorubicin and dioscin codelivery liposomes, which could enhance tumor targeting and inhibit tumor cell metastasis. Methods and results: Targeted daunorubicin and dioscin codelivery liposomes were prepared by film dispersion and the ammonium sulfate gradient method. With the ideal physicochemical properties, targeted daunorubicin and dioscin codelivery liposomes exhibited enhanced cellular uptake and showed strong cytotoxicity to tumor cells. The encapsulation of dioscin increased the inhibitory effects of daunorubicin on A549 cells, vasculogenic mimicry (VM) channels and tumor metastasis. The enhanced antimetastatic mechanism of the targeted liposomes was attributed to the downregulation of matrix metalloproteinase-2 (MMP-2), vascular endothelial cadherin (VE-Cad), transforming growth factor-β1 (TGF-β1) and hypoxia inducible factor-1α (HIF-1α). Meanwhile, the targeted daunorubicin and dioscin codelivery liposomes exhibited significant antitumor effects in tumor-bearing mice. H&E staining, immunohistochemistry with Ki-67 and TUNEL assay also showed the promoted antitumor activity of the targeted liposomes. Conclusion: Targeted daunorubicin and dioscin codelivery liposomes may provide an effective strategy for the treatment of NSCLC.

Engineering Nanoparticles for Targeted Delivery of Nucleic Acid Therapeutics in Tumor

In the past 10 years, with the increase of investment in clinical nano-gene therapy, there are many trials that have been discontinued due to poor efficacy and serious side effects. Therefore, it is particularly important to design a suitable gene delivery system. In this paper, we introduce the application of liposomes, polymers, and inorganics in gene delivery; also, different modifications with some stimuli-responsive systems can effectively improve the efficiency of gene delivery and reduce cytotoxicity and other side effects. Besides, the co-delivery of chemotherapy drugs with a drug tolerance-related gene or oncogene provides a better theoretical basis for clinical cancer gene therapy.

An aluminum adjuvant-integrated nano-MOF as antigen delivery system to induce strong humoral and cellular immune responses

Metal-organic frameworks (MOFs) have high surface area, tunable pore size, and high loading capacity, making them promising for drug delivery. However, their synthesis requires organic solvents, high temperature and high pressure that are incompatible with biomacromolecules. Zeolitic imidazole frameworks (ZIF-8) which forms through coordination between zinc ions and 2-methylimidazole (MeIM) have emerged as an advanced functional material for drug delivery due to its unique features such as high loading and pH-sensitive degradation. In this study, we took advantage of a natural biomineralization process to create aluminum-containing nanoZIF-8 particles for antigen delivery. Without organic solvents or stabilizing agent, nanoparticles (ZANPs) were synthesized by a mild and facile method with aluminum, model antigen ovalbumin (OVA) and ZIF-8 integrated. A high antigen loading capacity (%) of 30.6% and a pH dependent antigen release were achieved. A Toll-like receptor 9 agonist cytosine-phosphate-guanine oligodeoxynucleotides (CpG) was adsorbed on the surface of ZANPs (hereafter CpG/ZANPs) to boost the immune response. After subcutaneous injection in vivo, CpG/ZANPs targeted lymph nodes (LNs), where their cargo was efficiently internalized by LN-resident antigen-presenting cells (APCs). ZANPs decomposition in lysosomes released antigen into the cytoplasm and enhanced cross-presentation. Moreover, CpG/ZANPs induced strong antigen-specific humoral and cytotoxic T lymphocyte responses that significantly inhibited the growth of EG7-OVA tumors while showing minimal cytotoxicity. We demonstrate that ZANPs may be a safe and effective vehicle for the development of cancer vaccines.

1988-2018: Thirty years of drug smuggling at the nano scale. Challenges and opportunities of cell-penetrating peptides in biomedical research

In 1988, two unrelated papers reported the discovery of peptide vectors with innate cell translocation properties, setting the ground for a new area of research that over the years has grown into considerable therapeutic potential. The vectors, named cell-penetrating peptides (CPPs), constitute a now large and diversified family, sharing the extraordinary ability to diffuse unaltered across cell membranes while ferrying diverse associated cargos. Such properties have made CPPs ideal tools for delivery of nucleic acids, proteins and other therapeutic/diagnostic molecules to cells and tissues via covalent conjugation or complexation. This year 2018 marks the 30^th anniversary of a peptide research landmark opening new perspectives in drug delivery. Given its vastness, exhaustive coverage of the main features and accomplishments in the CPP field is virtually impossible. Hence this manuscript, after saluting the above 30^th jubilee, focuses by necessity on the most recent contributions, providing a comprehensive list of recognized CPPs and their latest-reported applications over the last two years. In addition, it thoroughly reviews three areas of peptide vector research of particular interest to us, namely (i) efficient transport of low-bioavailability drugs into the brain; (ii) CPP-delivered disruptors of G protein-coupled receptor (GPCRs) heteromers related to several disorders, and (iii) CPP-mediated delivery of useful but poorly internalized drugs into parasites.

The Improved Delivery to Breast Cancer Based on a Novel Nanocarrier Modified with High-Affinity Peptides Discovered by Phage Display

Ligand-targeted nanosystems have the potential to realize site-specific tumor therapy and alleviate unwanted side effects of many chemotherapeutic agents, and one of the most key issues seems to be the construction of an effective nanocarrier. Based on different processes of phage display techniques, 38 cell-binding peptides and 32 cell-internalizing peptides are discovered. Four of these ligand peptides [FIPFDPMSMRWE (FIP), NASSFPTNSRWA (NAS), GLHTSATNLYLH (GLH), and ALAVAPSRWWNE (ALA), respectively] exhibit high affinity to MCF7 human breast cancer cells. Among them, NAS and ALA are reported for the first time, whose affinities are 20.6 and 76.3 times that of the random peptide control, respectively. Both NAS and ALA modifications to doxorubicin-loaded lipid nanosytems [LP(DOX)] show stronger tumor inhibition, longer animal survival time, and less body weight loss, compared to unmodified or control peptide modified nanosystems, on an MCF7 tumor-bearing mouse model. In conclusion, the cell-binding peptide NAS and cell-internalizing peptide ALA can be used for ligand-targeted delivery of antitumor drugs. It seems that the in vivo antitumor effect of these ligand-targeted nanosystems is closely related to their ligand-cell affinity, but fairly tolerant of the ligand types.

Co-delivery of doxorubicin and erlotinib through liposomal nanoparticles for glioblastoma tumor regression using an in vitro brain tumor model

Glioma is a highly malignant tumor that starts in the glial cells of brain. Tumor cells reproduce quickly and infiltrate rapidly in high grade glioma. Permeability of chemotherapeutic agents into brain is restricted owing to the presence of blood brain barrier (BBB). In this study, we developed a dual functionalized liposomal delivery system for efficient transport of chemotherapeutics across BBB for the treatment of glioma. Liposomes were surface modified with transferrin (Tf) for receptor targeting, and cell penetrating peptide PFVYLI (PFV) to increase translocation of doxorubicin (Dox) and Erlotinib (Erlo) across the BBB into glioblastoma (U87) tumor cells. In vitro cytotoxicity and hemolysis studies were performed to assess biocompatibility of liposomal nanoparticles. Cellular uptake studies demonstrated efficient internalization of Dox and Erlo in U87, brain endothelial (bEnd.3), and glial cells. In addition, dual functionalized liposomes showed significantly (p < 0.05) higher apoptosis in U87 cells. Significantly (p < 0.05) higher translocation of dual functionalized liposomes across the BBB and delivering chemotherapeutic drugs to the glioblastoma tumor cells inside PLGA-Chitosan scaffold resulted in approximately 52% tumor cell death, using in vitro brain tumor model.

Dual-ligand modified liposomes provide effective local targeted delivery of lung-cancer drug by antibody and tumor lineage-homing cell-penetrating peptide

The abilities of a drug delivery system to target and penetrate tumor masses are key factors in determining the system’s chemotherapeutic efficacy. Here, we explored the utility of an anti-carbonic anhydrase IX (anti-CA IX) antibody and CPP33 dual-ligand modified triptolide-loaded liposomes (dl-TPL-lip) to simultaneously enhance the tumor-specific targeting and increase tumor cell penetration of TPL. In vitro, the dl-TPL-lip increased the cytotoxicity of TPL in CA IX-positive lung cancer cells, which showed tunable size (137.6 ± 0.8 nm), high-encapsulation efficiency (86.3 ± 2.6%) and sustained release. Dl-TPL-lip significantly improved the ability of liposomes to penetrate 3 D tumor spheroids and exhibited a superior inhibiting effect. Furthermore, pharmacokinetic studies in rats that received TPL liposomal formulations by endotracheal administration showed a reduced concentration of TPL (17.3%–30.6% compared to free TPL) in systemic circulation. After pulmonary administration in orthotopic lung tumor-bearing mice, dl-TPL-lip significantly enhanced TPL anti-cancer efficacy without apparent systemic toxicity. This dual-ligand modified liposomal vehicle presents a potential system for localized and targeted delivery of anti-cancer drugs to improve their efficacy.

The anticancer efficacy of paclitaxel liposomes modified with low-toxicity hydrophobic cell-penetrating peptides in breast cancer: an in vitro and in vivo evaluation

In our recent study, hydrophobic cell-penetrating peptides (CPPs) were demonstrated as an effective method of improving cancer treatment. To provide more evidence and broaden the application range for this promising strategy of improving cancer treatment, novel hydrophobic CPP-modified (PFV-modified) nanoliposomes loaded with paclitaxel, termed PFV-Lip-PTX, were developed as a treatment for breast cancer. Physicochemical evaluations of PFV-Lip-PTX revealed spheroid-like regular vesicles of about 120 nm in diameter with negative charge. An in vitro release study indicated that PTX was released from the liposomes in a controlled and sustained manner. A cellular uptake study indicated that PFV-Lip-PTX exhibited higher internalization efficiency in MCF-7 cells than non-modified liposomes. It was also demonstrated that PFV modification improved the cytotoxicity of PTX via a hydrophobic interaction between the PFV-Lip and cell lipid membranes compared with non-modified liposomes. Moreover, in vivo studies demonstrated that the PFV-modified liposomes led to highly efficient targeting and accumulation in an MCF-7 xenograft tumor and improved the antitumor efficacy of PTX. Finally, PFV-Lip-PTX showed low systemic toxicity evidenced by fewer changes in the body weights of mice and no visible histological changes in major healthy organs. Therefore, our results indicate that PFV-Lip-PTX has great potential in tumor-targeting and effective antitumor treatment.

Effective deactivation of A549 tumor cells in vitro and in vivo by RGD-decorated chitosan-functionalized single-walled carbon nanotube loading docetaxel

This study aims to construct and evaluate RGD-decorated chitosan (CS)-functionalized pH-responsive single-walled carbon nanotube (SWCNT) carriers using docetaxel (DTX) as a model anticancer drug. DTX was loaded onto SWCNT via π-π stacking interaction (SWCNT-DTX), followed by the non-covalent conjugation of RGD-decorated CS to SWCNT-DTX to prepare RGD-CS-SWCNT-DTX. The RGD-CS-SWCNT-DTX showed significantly higher drug release than the pure drug, giving higher release rate at pH 5.0 (68%) than pH 7.4 (49%). The RGD-CS-SWCNT-DTX could significantly inhibit the growth of A549 tumor cells in vitro, and the uptake amount of A549 cells was obviously higher than that of MCF-7 cells. Meanwhile, the cellular uptake of RGD-CS-SWCNT-DTX was higher than that of CS-SWCNT-DTX in A549 cells, mainly through clathrin and caveolae-mediated endocytosis. The RGD-CS-SWCNT-DTX significantly inhibited tumor growth of A549 cell-bearing nude mice through active tumor-targeting ability. Furthermore, no pathological changes were found in tissues and organs. The result demonstrated that RGD-CS-SWCNT-DTX displayed high drug loading, pH-responsive drug release, remarkable antitumor effect in vitro and in vivo, and also good safety to animal body.

Smart Nanoparticles Undergo Phase Transition for Enhanced Cellular Uptake and Subsequent Intracellular Drug Release in a Tumor Microenvironment

Inefficient cellular uptake and intracellular drug release at the tumor site are two major obstacles limiting the antitumor efficacy of nanoparticle delivery systems. To overcome both problems, we designed a smart nanoparticle that undergoes phase transition in a tumor microenvironment (TME). The smart nanoparticle is generated using a lipid-polypetide hybrid nanoparticle, which comprises a PEGylated lipid monolayer shell and a pH-sensitive hydrophobic poly-l-histidine core and is loaded with the antitumor drug doxorubicin (DOX). The smart nanoparticle undergoes a two-step phase transition at two different pH values in the TME: (i) At the TME (pH_e: 7.0-6.5), the smart nanoparticle swells, and its surface potential turns from negative to neutral, facilitating the cellular uptake; (ii) After internalization, at the acid endolysosome (pH_endo: 6.5-4.5), the smart nanoparticle dissociates and induces endolysosome escape to release DOX into the cytoplasm. In addition, a tumor-penetrating peptide iNRG was modified on the surface of the smart nanoparticle as a tumor target moiety. The in vitro studies demonstrated that the iNGR-modified smart nanoparticles promoted cellular uptake in the acidic environment (pH 6.8). The in vivo studies showed that the iNGR-modified smart nanoparticles exerted more potent antitumor efficacy against late-stage aggressive breast carcinoma than free DOX. These data suggest that the smart nanoparticles may serve as a promising delivery system for sequential uptake and intracellular drug release of antitumor agents. The easy preparation of these smart nanoparticles may also have advantages in the future manufacture for clinical trials and clinical use.

Research progresses on the functional polypeptides in the detection and imaging of breast cancer

Polypeptides as functional groups continue to garner significant interest in the detection and imaging of breast cancer, working as recognition elements, signal sources, building blocks and therapeutic reagents, etc.

Hydrophobic binding peptide-conjugated hybrid lipid-mesoporous silica nanoparticles for effective chemo-photothermal therapy of pancreatic cancer

Nanoparticle-based drug delivery systems are designed to reach tumor sites based on their enhanced permeation and retention effects. However, a lack of interaction of these nanoparticles with cancer cells might lead to reduced uptake in the tumors, which might compromise the therapeutic efficacy of the system. Therefore, we developed bortezomib and IR-820-loaded hybrid-lipid mesoporous silica nanoparticles conjugated with the hydrophobic-binding peptide, cyclosporine A (CsA), and referred to them as CLMSN/BIR. Upon reaching the tumor site, CsA interacts hydrophobically with the cancer cell membranes to allow effective uptake of the nanoparticles. Nanoparticles ∼160 nm in size were prepared and the stability of IR-820 significantly improved. High cellular uptake of the nanoparticles was evident with pronounced apoptotic effects in PANC-1 and MIA PaCa-2 cells that were mediated by the chemotherapeutic effect of bortezomib and the photothermal and reactive oxygen species generation effects of IR-820. An in vivo biodistribution study indicated there was high accumulation in the tumor with an enhanced photothermal effect in PANC-1 xenograft mouse tumors. Furthermore, enhanced antitumor effects in PANC-1 xenograft tumors were observed with minimal toxicity induction in the organs of mice. Cumulatively, these results indicated the promising effects of CLMSN/BIR for effective chemo-phototherapy of pancreatic cancers.