Active Tumor Targeting Research Articles

Folate-Decorated Cross-Linked Cytochrome c Nanoparticles for Active Targeting of Non-Small Cell Lung Carcinoma (NSCLC).

The folate receptor alpha (FR), which is overexpressed in solid tumors including NSCLC, can be utilized for active tumor targeting to afford more effective cancer therapies. In this context, cytochrome c (Cyt c) has drawn attention to cancer research because it is non-toxic, yet, when delivered to the cytoplasm of cancer cells, can kill them by inducing apoptosis. Cyt c nanoparticles (NPs, 169 ± 9 nm) were obtained by solvent precipitation with acetonitrile, and stabilized by reversible homo-bifunctional crosslinking to accomplish a Cyt-c-based drug delivery system that combines stimulus-responsive release and active targeting. Cyt c was released under intracellular redox conditions, due to an S–S bond in the NPs linker, while NPs remained intact without any release under extracellular conditions. The NP surface was decorated with a hydrophilic folic acid–polyethylene glycol (FA–PEG) polymer for active targeting. The FA-decorated NPs specifically recognized and killed cancer cells (IC50 = 47.46 µg/mL) that overexpressed FR, but showed no toxicity against FR-negative cells. Confocal microscopy confirmed the preferential uptake and apoptosis induction of our NPs by FR-positive cancer cells. In vivo experiments using a Lewis lung carcinoma (LLC) mouse model showed visible NP accumulation within the tumor and inhibited the growth of LLC tumors.

Synergic fabrication of multifunctional liposomes nanocomposites for improved radiofrequency ablation combination for liver metastasis cancer therapy

The field of biomedical research has recently been interested in nanoplatforms with various functionalities, such as cancer drug carriers and MRI and optical imaging, as well as thermal treatment, among other things. As a result of the present investigation, a unique multifunctional liposome (MFL) was established in this investigation. Using radiofrequency-induced imaging and drug release based on magnetic field impact, a dual drug delivery targeted with tumor multi-mechanism treatment was made more effective. The C60 (fullerene) surface was coated with iron nanocomposites to establish the proposed nanosystems, and PEGylation was used (Fe3O4-C60-PEG2000). For fullerene radiofrequency-triggered drug release, thermosensitive DPPC liposomes with folate-DSPE-PEG2000 enveloped the binary nanosystems and doxorubicin (DOX). The in vitro cytotoxicity of the nanocomposites was confirmed by the liver metastasis in HT-29 colon cancer cells using radiofrequency. The flow cytometry analysis confirmed the apoptosis cell death mechanism. The thermal treatment combined chemotherapeutic MFL nano framework transformed radiofrequency radiation from thermoresponsive liposomes, which was noticed both in vivo and in vitro. Due to their superior active tumor targeting and magnetic targeting characteristics, the MFL could also selectively destroy cancerous liver cells in highly co-localized targets.

Molecularly imprinted upconversion nanoparticles for active tumor targeting and microinvasive photothermal therapy

Molecularly imprinted upconversion nanoparticles for active tumor targeting and microinvasive photothermal therapy

Nanobugs as Drugs: Bacterial Derived Nanomagnets Enhance Tumor Targeting and Oncolytic Activity of HSV-1 Virus.

The survival strategies of infectious organisms have inspired many therapeutics over the years. Indeed the advent of oncolytic viruses (OVs) exploits the uncontrolled replication of cancer cells for production of their progeny resulting in a cancer-targeting treatment that leaves healthy cells unharmed. Their success against inaccessible tumors however, is highly variable due to inadequate tumor targeting following systemic administration. Coassembling herpes simplex virus (HSV1716) with biocompatible magnetic nanoparticles derived from magnetotactic bacteria enables tumor targeting from circulation with magnetic guidance, protects the virus against neutralizing antibodies and thereby enhances viral replication within tumors. This approach additionally enhances the intratumoral recruitment of activated immune cells, promotes antitumor immunity and immune cell death, thereby inducing tumor shrinkage and increasing survival in a syngeneic mouse model of breast cancer by 50%. Exploiting the properties of such a nanocarrier, rather than tropism of the virus, for active tumor targeting offers an exciting, novel approach for enhancing the bioavailability and treatment efficacy of tumor immunotherapies for disseminated neoplasms.

Effect of the structure of ginsenosides on the in vivo fate of their liposomes

To utilize the multiple functions and give full play of ginsenosides, a variety of ginsenosides with different structures were prepared into liposomes and evaluated for their effect on the stability, pharmacokinetics and tumor targeting capability of liposomes. The results showed that the position and number of glycosyl groups of ginsenosides have significant effect on the in vitro and in vivo properties of their liposomes. The pharmacokinetics of ginsenosides liposomes indicated that the C-3 sugar group of ginsenosides is beneficial to their liposomes for longer circulation in vivo. The C-3 and C-6 glycosyls can enhance the uptake of their liposomes by 4T1 cells, and the glycosyls at C-3 position can enhance the tumor active targeting ability significantly, based on the specific binding capacity to Glut 1 expressed on the surface of 4T1 cells. According to the results in the study, ginsenoside Rg3 and ginsenoside Rh2 are potential for exploiting novel liposomes because of their cholesterol substitution, long blood circulation and tumor targeting capabilities. The results provide a theoretical basis for further development of ginsenoside based liposome delivery systems.

Construction of multifunctional carboxymethyl cellulose nanohydrogel carriers based on near-infrared DNA-templated quantum dots for tumor theranostics

Multifunctional therapeutic platforms with targeted delivery, fast diagnosis, and efficient therapy could effectively reduce side effects and improve treatment in the clinical therapy of tumors. Near-infrared DNA-templated CdTeSe quantum dots (DNA-CdTeSe QDs) were developed as building blocks to construct a multifunctional carboxymethyl cellulose (CMC)-based nanohydrogel as a nanocarrier to address the challenges of serious side effects and precise treatment in cancer theranostics, including active tumor targeting, fluorescence tracking, controlled drug release, chemotherapy and gene regulation. Single-stranded DNA containing the complementarity sequence of miRNA and cystine, as co-crosslinkers, initiated hybridization between the DNA-CdTeSe QD-modified CMC chain with the anti-nucleolin aptamer DNA (AS1411)-modified CMC chain to form the hydrogels. DOX, as a model drug, was successfully incorporated into the hydrogels. The synthesized multifunctional hydrogel nanocarriers with an average diameter of 150 nm could be taken up through targeting and achieved the controlled release of DOX by triggering both glutathione (GSH) and miRNA in the tumor microenvironment. The CdTeSe QDs trapped in nanohydrogels acted as fluorophores for bioimaging in the diagnosis and treatment process. The proposed multifunctional delivery system provided a potential platform for tumor imaging and precise therapy.

Effects of iRGD conjugation density on the in vitro and in vivo properties of cylindrical polymer brushes.

iRGD can significantly improve the tumor accumulation and tumor penetration of nanomaterials. However, it still remains unclear how far iRGD can enhance the properties of nanomaterials when its conjugation density is maximized. Herein, we synthesized three types of cylindrical polymer brushes (CPBs) with 0%, 50% and 100% of side chains terminated by iRGD, which were named CPBs-1, CPBs-2 and CPBs-3, respectively, and studied the effects of iRGD density on their cellular uptake, and tumor targeting ability and tumor permeability. It was demonstrated that compared with the iRGD-free CPBs-1, the cellular uptake of CPBs-3 was enhanced 5 times and their tumor accumulation was enhanced twice. The penetration depth of CPBs-3 in three-dimensional multicellular spheroids was larger than 100 μm. Our results provide useful information for the design of active tumor targeting nanomaterials as therapeutics or contrast agents.

Gold Nanoclusters: Imaging, Therapy, and Theranostic Roles in Biomedical Applications.

For the past two decades, atomic gold nanoclusters (AuNCs, ultrasmall clusters of several to 100 gold atoms, having a total diameter of <2 nm) have emerged as promising agents in the diagnosis and treatment of cancer. Owing to their small size, significant quantization occurs to their conduction band, which leads to emergent photonic properties and the disappearance of the plasmonic responses observed in larger gold nanoparticles. For example, AuNCs exhibit native luminescent properties, which have been well-explored in the literature. Using proteins, peptides, or other biomolecules as structural scaffolds or capping ligands, required for the stabilization of AuNCs, improves their biocompatibility, while retaining their distinct optical properties. This paved the way for the use of AuNCs in fluorescent bioimaging, which later developed into multimodal imaging combined with computer tomography and magnetic resonance imaging as examples. The development of AuNC-based systems for diagnostic applications in cancer treatment was then made possible by employing active or passive tumor targeting strategies. Finally, the potential therapeutic applications of AuNCs are extensive, having been used as light-activated and radiotherapy agents, as well as nanocarriers for chemotherapeutic drugs, which can be bound to the capping ligand or directly to the AuNCs via different mechanisms. In this review, we present an overview of the diverse biomedical applications of AuNCs in terms of cancer imaging, therapy, and combinations thereof, as well as highlighting some additional applications relevant to biomedical research.

A branched small molecule-drug conjugate nanomedicine strategy for the targeted HCC chemotherapy

Off-target toxicity is one of the main challenges faced by anticancer chemotherapeutics. For tumor targeted and precision chemotherapy, we take the advantages of the ligand directed tumor active targeting of small molecule drug conjugates (SMDCs) and the passive tumor targeting of nanoparticles via the enhanced penetration and retention (EPR) effects, put forward a branched small molecule drug conjugate (BSMDC) nanomedicine design concept. In a proof of concept, we used pentaerythritol as the branched moiety, galactosamine (GalN) as the hepatocellular carcinoma (HCC) directing ligands, PTX as a payload, and a stearoyl moiety as the amphiphilic property adjusting group, designed and synthesized BSMDC 1 and prepared its NPs. In cellular level, the BSMDC 1 NPs targeted asialoglycoprotein receptor (ASGPR)-overexpressing HepG2 cells, were effectively taken up in the cells and released in tumor microenvironments, inhibited the HepG2 cell proliferation, arrested HepG2 cell in G2/M phase and induced tumor cell apoptosis. In HepG2 xenograft nude mice, the BSMDC 1 NPs were high specific to target the tumor and demonstrated a higher antitumor efficiency than BSMDC 1, having no apparent influences on mice body weights and major organs, supporting our BSMDC nanomedicine design concept. Therefore, this new strategy may find applications for cancer targeted and precision chemotherapy.

Hypoxia-sensitive drug delivery to tumors

Achievement of a high dose of drug in the tumor while minimizing its systemic side effects is one of the important features of an improved drug delivery system. Thus, developing responsive carriers for site-specific delivery of chemotherapeutic agents has become a main goal of research efforts. One of the known hallmarks of cancerous tumors is hypoxia, which offers a target for selective drug delivery. The stimuli-sensitive micellar system developed by us, (PEG-azobenzene-PEI-DOPE (PAPD) has proven to be effective in vitro. The proposed construct developed, PAPD, contains an azobenzene group as a hypoxia-sensitive moiety that triggers the shedding of the PEG layer from the nanoparticle surface under conditions of hypoxia to improve cellular uptake. Using microfluidics, we show significantly improved cellular association and penetration under hypoxia in both single cells and in a 3D tumor model. Employing an in vivo model, we demonstrate slower tumor growth that did not induce systemic side effects, including weight loss in an experimental animal model, when compared to the free drug treatment. This complex-in-nature but simple-in-design system for the simultaneous delivery of siRNA to silence the P-glycoprotein and doxorubicin with active tumor targeting and proven therapeutic efficacy represents a universal platform for the delivery of other hydrophobic chemotherapeutic agents and siRNA molecules which can be further modified.

Hyaluronan-coated nanoparticles for active tumor targeting: Influence of polysaccharide molecular weight on cell uptake

Here we aimed to correlate different molecular weights of hyaluronic acid (HA), 200, 800 and 1437 kDa, used to decorate poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles (NPs), to their cell uptakes. NP internalization kinetics in CD44-overexpressing breast carcinoma cells were quantified, using healthy fibroblast cells as reference. Actually, NP uptake and selectivity by tumor cells were maximized for NPs HA 800 kDa, while being minimum for NPs HA1400 kDa. This unexpected result could be explained considering that the interaction between NPs and tumor cells is dictated by rearrangement and conformation of that segment of HA chain that actually protrudes from the NPs. Overall, results obtained in this work point at how HA molecular weight, is pivotal project parameter in NP formulation to promote active targeting in the CD44 overexpressing cancer cells.

Dual-ligated metal organic framework as novel multifunctional nanovehicle for targeted drug delivery for hepatic cancer treatment

In the last decade, nanosized metal organic frameworks (NMOFs) have gained an increasing applicability as multifunctional nanocarriers for drug delivery in cancer therapy. However, only a limited number of platforms have been reported that can serve as an effective targeted drug delivery system (DDSs). Herein, we report rational design and construction of doxorubicin (DOX)-loaded nanoscale Zr (IV)-based NMOF (NH2-UiO-66) decorated with active tumor targeting moieties; folic acid (FA), lactobionic acid (LA), glycyrrhetinic acid (GA), and dual ligands of LA and GA, as efficient multifunctional DDSs for hepatocellular carcinoma (HCC) therapy. The success of modification was exhaustively validated by various structural, thermal and microscopic techniques. Biocompatibility studies indicated the safety of pristine NH2-UiO-66 against HSF cells whereas DOX-loaded dual-ligated NMOF was found to possess superior cytotoxicity against HepG2 cells which was further confirmed by flow cytometry. Moreover, fluorescence microscopy was used for monitoring cellular uptake in comparison to the non-ligated and mono-ligated NMOF. Additionally, the newly developed dual-ligated NMOF depicted a pH-responsiveness towards the DOX release. These findings open new avenues in designing various NMOF-based DDSs that actively target hepatic cancer to achieve precise therapy.

PH-Sensitive Molecular-Switch-Containing Polymer Nanoparticle for Breast Cancer Therapy with Ferritinophagy-Cascade Ferroptosis and Tumor Immune Activation.

Ferritin internalized into tumor cells is degraded and releases iron ions via ferritinophagy. Iron ions participate in Fenton reaction to produce reactive oxygen species for lipid peroxidation and ferroptosis. Inhibition of indoleamine-2,3-dioxygenase (IDO) decreases tryptophan elimination to induce Tcells activation for tumor immunosuppression relief. The active tumor targeting nanoparticles containing ferritin and a pH-sensitive molecular-switch (FPBC@SN) are developed to utilize ferritinophagy-cascade ferroptosis and tumor immunity activation for cancer therapy. FPBC@SN disintegrates in acidic cytoplasm and releases sorafenib (SRF) and IDO inhibitor (NLG919). SRF upregulates nuclear receptor coactivator 4 (NCOA4) to induce ferritin and endogenous iron pool degradation by ferritinophagy, then obtained iron ions participate in the Fenton reaction to produce lipid peroxide (LPO). Meanwhile, SRF blocks glutathione synthesis to downregulate glutathione peroxidase 4 (GPX4) which can scavenge LPO as a different pathway from ferritinophagy to promote ferroptosis in tumor cells. NLG919 inhibits IDO to reduce tryptophan metabolism, so immunity in tumors is aroused to anti-tumor. In vitro and in vivo experiments prove FPBC@SN inhibits tumor cell growth and metastasis, indicating the potential of FPBC@SN for breast cancer therapy based on the combination of ferritinophagy-cascade ferroptosis and tumor immunity activation.

SiRNA-Loaded Hydroxyapatite Nanoparticles for KRAS Gene Silencing in Anti-Pancreatic Cancer Therapy.

Pancreatic carcinoma (PC) is greatly induced by the KRAS gene mutation, but effective targeted delivery for gene therapy has not existed. Small interfering ribonucleic acid (siRNA) serves as an advanced therapeutic modality and holds great promise for cancer treatment. However, the development of a non-toxic and high-efficiency carrier system to accurately deliver siRNA into cells for siRNA-targeted gene silencing is still a prodigious challenge. Herein, polyethylenimine (PEI)-modified hydroxyapatite (HAp) nanoparticles (HAp-PEI) were fabricated. The siRNA of the KRAS gene (siKras) was loaded onto the surface of HAp-PEI via electrostatic interaction between siRNA and PEI to design the functionalized HAp-PEI nanoparticle (HAp-PEI/siKras). The HAp-PEI/siKras was internalized into the human PC cells PANC-1 to achieve the maximum transfection efficiency for active tumor targeting. HAp-PEI/siKras effectively knocked down the expression of the KRAS gene and downregulated the expression of the Kras protein in vitro. Furthermore, the treatment with HAp-PEI/siKras resulted in greater anti-PC cells’ (PANC-1, BXPC-3, and CFPAC-1) efficacy in vitro. Additionally, the HAp-PEI exhibited no obvious in vitro cytotoxicity in normal pancreatic HPDE6-C7 cells. These findings provided a promising alternative for the therapeutic route of siRNA-targeted gene engineering for anti-pancreatic cancer therapy.

Tumor-self-targeted “thermoferroptosis-sensitization” magnetic nanodroplets for multimodal imaging-guided tumor-specific therapy

Ferroptosis-based nanomedicine has drawn increasing attention in antitumor therapy because of the advantages of this unconventional mode of apoptosis, but the difficulties of delivery to the tumor site and surface-to-core penetration after arrival seriously hinder further clinical transformation and application. Herein, we propose an unprecedented strategy of injecting magnetic nanodroplets (MNDs) to solve these two longstanding problems. MNDs are nanocarriers that can carry multifunctional drugs and imaging materials. MNDs can effectively accumulate in the tumor site by active tumor targeting (multifunctional drugs) and passive tumor targeting (enhanced permeability and retention effect), allowing diffusion of the MNDs from the surface to the core through mild-temperature magnetic fluid hyperthermia (MHT) under multimodal imaging guidance. Finally, the ferroptosis pathway is activated deep within the tumor site through the drug release. This approach was inspired by the ability of mild-temperature MHT to allow MNDs to quickly pass through the blood vessel-tumor barrier and deeply penetrate the tumor tissue from the surface to the core to amplify the antitumor efficacy of ferroptosis. This strategy is termed as “thermoferroptosis sensitization”. Importantly, this behavior can be performed under the guidance of multimodal imaging, making the design of MNDs for cancer therapy safer and more reasonable.

Arsenene-mediated multiple independently targeted reactive oxygen species burst for cancer therapy

The modulation of intracellular reactive oxygen species (ROS) levels is crucial for cellular homeostasis and determination of cellular fate. A sublethal level of ROS sustains cell proliferation, differentiation and promotes tumor metastasis, while a drastic ROS burst directly induces apoptosis. Herein, surface-oxidized arsenene nanosheets (As/AsxOy NSs) with type II heterojunction are fabricated with efficient ·O2− and 1O2 production and glutathione consumption through prolonging the lifetime of photo-excited electron-hole pairs. Moreover, the portion of AsxOy with oxygen vacancies not only catalyzes a Fenton-like reaction, generating ·OH and O2 from H2O2, but also inactivates main anti-oxidants to cut off the “retreat routes” of ROS. After polydopamine (PDA) and cancer cell membrane (M) coating, the engineered As/AsxOy@PDA@M NSs serve as an intelligent theranostic platform with active tumor targeting and long-term blood circulation. Given its narrow-band-gap-enabled in vivo fluorescence imaging properties, As/AsxOy@PDA@M NSs could be applied as an imaging-guided non-invasive and real-time nanomedicine for cancer therapy.

The Therapeutic Effect of Human Serum Albumin Dimer-Doxorubicin Complex against Human Pancreatic Tumors.

Human serum albumin (HSA) is a versatile drug carrier with active tumor targeting capacity for an antitumor drug delivery system. Nanoparticle albumin-bound (nab)-technology, such as nab-paclitaxel (Abraxane®), has attracted significant interest in drug delivery research. Recently, we demonstrated that HSA dimer (HSA-d) possesses a higher tumor distribution than HSA monomer (HSA-m). Therefore, HSA-d is more suitable as a drug carrier for antitumor therapy and can improve nab technology. This study investigated the efficacy of HSA-d-doxorubicin (HSA-d-DOX) as next-generation nab technology for tumor treatment. DOX conjugated to HSA-d via a tunable pH-sensitive linker for the controlled release of DOX. Lyophilization did not affect the particle size of HSA-d-DOX or the release of DOX. HSA-d-DOX showed significantly higher cytotoxicity than HSA-m-DOX in vitro. In the SUIzo Tumor-2 (SUIT2) human pancreatic tumor subcutaneous inoculation model, HSA-d-DOX could significantly inhibit tumor growth without causing serious side effects, as compared to the HSA binding DOX prodrug, which utilized endogenous HSA as a nano-drug delivery system (DDS) carrier. These results indicate that HSA-d could function as a natural solubilizer of insoluble drugs and an active targeting carrier in intractable tumors with low vascular permeability, such as pancreatic tumors. In conclusion, HSA-d can be an effective drug carrier for the antitumor drug delivery system against human pancreatic tumors.

Optimizing Active Tumor Targeting Biocompatible Polymers for Efficient Systemic Delivery of Adenovirus.

Adenovirus (Ad) has risen to be a promising alternative to conventional cancer therapy. However, systemic delivery of Ad, which is necessary for the treatment of metastatic cancer, remains a major challenge within the field, owing to poor tumor tropism and nonspecific hepatic tropism of the virus. To address this limitation of Ad, we have synthesized two variants of folic acid (FA)-conjugated methoxy poly(ethylene glycol)-b-poly{N-[N-(2-aminoethyl)-2-aminoethyl]-L-glutamate (P5N2LG-FA and P5N5LG-FA) using 5 kDa poly(ethylene glycol) (PEG) with a different level of protonation (N2 < N5 in terms of charge), along with a P5N5LG control polymer without FA. Our findings demonstrate that P5N5LG, P5N2LG-FA, and P5N5LG-FA exert a lower level of cytotoxicity compared to 25 kDa polyethyleneimine. Furthermore, green fluorescent protein (GFP)-expressing Ad complexed with P5N2LG-FA and P5N5LG-FA (Ad/P5N2LG-FA and Ad/P5N5LG-FA, respectively) exerted superior transduction efficiency compared to naked Ad or Ad complexed with P5N5LG (Ad/P5N5LG) in folate receptor (FR)-overexpressing cancer cells (KB and MCF7). All three nanocomplexes (Ad/P5N5LG, Ad/P5N2LG-FA, and Ad/P5N5LG-FA) internalized into cancer cells through coxsackie adenovirus receptor-independent endocytic mechanism and the cell uptake was more efficient than naked Ad. Importantly, the cell uptake of the two FA functionalized nanocomplexes (Ad/P5N2LG-FA and Ad/P5N5LG-FA) was dependent on the complementary interaction of FA–FR. Systemically administered Ad/P5N5LG, Ad/P5N2LG-FA, and Ad/P5N5LG-FA showed exponentially higher retainment of the virus in blood circulation up to 24 h post-administration compared with naked Ad. Both tumor-targeted nanocomplexes (Ad/P5N2LG-FA and Ad/P5N5LG-FA) showed significantly higher intratumoral accumulation than naked Ad or Ad/P5N5LG via systemic administration. Both tumor-targeted nanocomplexes accumulated at a lower level in liver tissues compared to naked Ad. Notably, the nonspecific accumulation of Ad/P5N2LG-FA was significantly lower than Ad/P5N5LG-FA in several normal organs, while exhibiting a significantly higher intratumoral accumulation level, showing that careful optimization of polyplex surface charge is critical to successful tumor-targeted systemic delivery of Ad nanocomplexes.

Co-delivery of paclitaxel and STAT3 siRNA by a multifunctional nanocomplex for targeted treatment of metastatic breast cancer

Metastasis is one of the major causes of mortality in patients suffering from breast cancer. The signal transducer and activator of transcription 3 (STAT3) is closely related to cancer metastasis. Herein, a multifunctional nanocomplex was developed to simultaneously deliver paclitaxel (PTX) and STAT3 siRNA (siSTAT3) to inhibit tumor growth and prevent metastasis of breast cancer cells. PTX was encapsulated into the synthesized polyethyleneimine-polylactic acid-lipoic acid (PPL) micelle through hydrophobic interaction, while siSTAT3 was condensed onto polyethyleneimine through electrostatic interaction. The surface charge of the drug-loaded nanocomplex (siSTAT3PPLPTX) was then converted to negative by coating with hyaluronic acid (HA). The multifunctional nanocomplex (HA/siSTAT3PPLPTX) effectively entered CD44-overexpressed 4T1 cells via an active targeting mechanism. HA shell was degraded by the concentrated hyaluronidase in the endo/lysosome and the rapid drug release was triggered by the redox micro-environment of cytoplasm. Moreover, HA/siSTAT3PPLPTX showed enhanced cytotoxicity against tumor cells due to a synergistic effect of PTX and siSTAT3. The effective inhibition of tumor metastasis was confirmed by in vitro cell migration and invasion in 4T1 cells. More importantly, a superior antitumor efficacy was observed in orthotopic 4T1 tumor-bearing mice, with no side effects in major organs, and the lung metastasis was strongly inhibited in 4T1 metastasis model. In conclusion, the multifunctional nanocomplex provides a versatile platform for efficient treatment of metastatic cancer through tumor-targeted chemo-gene combined therapy. Statement of significanceMetastasis is one of the major causes of mortality in patients suffering from breast cancer. The signal transducer and activator of transcription 3 (STAT3) is closely related to cancer metastasis. In this study, a multifunctional nanocomplex co-loaded with paclitaxel (PTX) and STAT3 siRNA was constructed and characterized. The co-delivery system exhibited active tumor targeting, effective endo/lysosomal escape, and rapid intracellular drug release. Both in vitro and in vivo studies indicated that the nanocomplex could lead to superior tumor growth inhibition, as well as metastasis suppression by silencing expression of STAT3 and p-STAT3. This present study implies that the nanocomplex could be a potential platform for targeted treatment of metastatic cancer through chemo-gene combined therapy.

Novel CD44-targeting and pH/redox-dual-stimuli-responsive core\u2013shell nanoparticles loading triptolide combats breast cancer growth and lung metastasis

BackgroundThe toxicity and inefficient delivery of triptolide (TPL) in tumor therapy have greatly limited the clinical application. Thus, we fabricated a CD44-targeting and tumor microenvironment pH/redox-sensitive nanosystem composed of hyaluronic acid-vitamin E succinate and poly (β-amino esters) (PBAEss) polymers to enhance the TPL-mediated suppression of breast cancer proliferation and lung metastasis.ResultsThe generated TPL nanoparticles (NPs) had high drug loading efficiency (94.93% ± 2.1%) and a desirable average size (191 nm). Mediated by the PBAEss core, TPL/NPs displayed a pH/redox-dual-stimuli-responsive drug release profile in vitro. Based on the hyaluronic acid coating, TPL/NPs exhibited selective tumor cellular uptake and high tumor tissue accumulation capacity by targeting CD44. Consequently, TPL/NPs induced higher suppression of cell proliferation, blockage of proapoptotic and cell cycle activities, and strong inhibition of cell migration and invasion than that induced by free TPL in MCF-7 and MDA-MB-231 cells. Importantly, TPL/NPs also showed higher efficacy in shrinking tumor size and blocking lung metastasis with decreased systemic toxicity in a 4T1 breast cancer mouse model at an equivalent or lower TPL dosage compared with that of free TPL. Histological immunofluorescence and immunohistochemical analyses in tumor and lung tissue revealed that TPL/NPs induced a high level of apoptosis and suppressed expression of matrix metalloproteinases, which contributed to inhibiting tumor growth and pulmonary metastasis.ConclusionCollectively, our results demonstrate that TPL/NPs, which combine tumor active targeting and pH/redox-responsive drug release with proapoptotic and antimobility effects, represent a promising candidate in halting breast cancer progression and metastasis while minimizing systemic toxicity.Graphic