Targeted anti-cancer therapy: Co-delivery of VEGF siRNA and Phenethyl isothiocyanate (PEITC) via cRGD-modified lipid nanoparticles for enhanced anti-angiogenic efficacy

Anti-tumor angiogenesis therapy, targeting the suppression of blood vessel growth in tumors, presents a potent approach in the battle against cancer. Traditional therapies have primarily concentrated on single-target techniques, with a specific emphasis on targeting the vascular endothelial growth factor, but have not reached ideal therapeutic efficacy. In response to this issue, our study introduced a novel nanoparticle system known as CS-siRNA/PEITC&L-cRGD NPs. These chitosan-based nanoparticles have been recognized for their excellent biocompatibility and ability to deliver genes. To enhance their targeted delivery capability, they were combined with a cyclic RGD peptide (cRGD). Targeted co-delivery of gene and chemotherapeutic agents was achieved through the use of a negatively charged lipid shell and cRGD, which possesses high affinity for integrin αvβ3 overexpressed in tumor cells and neovasculature. In this multifaceted approach, co-delivery of VEGF siRNA and phenethyl isothiocyanate (PEITC) was employed to target both tumor vascular endothelial cells and tumor cells simultaneously. The co-delivery of VEGF siRNA and PEITC could achieve precise silencing of VEGF, inhibit the accumulation of HIF-1α under hypoxic conditions, and induce apoptosis in tumor cells. In summary, we have successfully developed a nanoparticle delivery platform that utilizes a dual mechanism of action of anti-tumor angiogenesis and pro-tumor apoptosis, which provides a robust and potent strategy for the delivery of anti-cancer therapeutics.

Co-Delivery of Repurposing Itraconazole and VEGF siRNA by Composite Nanoparticulate System for Collaborative Anti-Angiogenesis and Anti-Tumor Efficacy against Breast Cancer

Combinations of two different therapeutic modalities of VEGF inhibitors against angiogenesis can cooperatively impede breast cancer tumor growth and enhance therapeutic efficacy. Itraconazole (ITZ) is a conventional antifungal drug with high safety; however, it has been repurposed to be a multi target anti-angiogenesis agent for cancer therapy in recent years. In the present study, composite nanoparticles co-loaded with ITZ and VEGF siRNA were prepared in order to investigate their anti-angiogenesis efficacy and synergistic anticancer effect against breast cancer. The nanoparticles had a suitable particle size (117.9 ± 10.3 nm) and weak positive surface charge (6.69 ± 2.46 mV), as well as good stability and drug release profile in vitro. Moreover, the nanoparticles successfully escaped from endosomes and realized cell apoptosis and cell proliferation inhibition in vitro. In vitro and in vivo experiments showed that the nanoparticles could induce the silencing of VEGF-related expressions as well as anti-angiogenesis efficacy, and the co-loaded ITZ-VEGF siRNA NPs could inhibit tumor growth effectively with low toxicity and side effects. Taken together, the as-prepared delivery vehicles are a simple and safe nano-platform that improves the antitumor efficacy of VEGF siRNA and ITZ, which allows the repositioning of the generic drug ITZ as a great candidate for antitumor therapy.

Dual-targeted lung cancer therapy via inhalation delivery of UCNP-siRNA-AS1411 nanocages

OBJECTIVE

Although great progress has been made in the field of siRNA gene therapy, safe, efficient, and targeted delivery of siRNA are still major challenges in siRNA therapeutics.

METHODS

We developed an up-conversion nanoparticle-based nanocage system. This system protected the siRNA from being degraded by nucleases in organisms and selectively delivered the siRNAs to the tumor sites, due to modifications of targeted molecules on the surfaces of nanocages and local inhalation.

RESULTS

The siRNAs delivered by the up-conversion nanoparticle nanocages were protected from degradation in transit to the tumor sites, where they accumulated. Compared with the passive target and control groups, the up-conversion nanoparticles based on the nanocage system showed a tumor suppressive effect after approximately 3 weeks of treatment.

CONCLUSIONS

The up-conversion nanoparticle nanocages efficiently delivered vascular endothelial growth factor siRNAs to tumor sites. Mice with lung tumors treated with tumors targeting up-conversion nanoparticle nanocages showed steady body weight changes, high tumor inhibition ratios, and longer survival times.

Smart Polymeric Nanoparticles with pH-Responsive and PEG-Detachable Properties (II): Co-Delivery of Paclitaxel and VEGF siRNA for Synergistic Breast Cancer Therapy in Mice

Background

The dual-loaded nano-delivery system can realize chemotherapeutic drug and small interfering RNA (siRNA) co-loading as well as enhance the therapeutic effect of drugs on tumors through a synergistic effect, while reducing their toxic and side effects on normal tissues.

Methods

Previously, we developed layered smart nanoparticles (NPs) to co-deliver survivin siRNA as well as small molecule drugs for lung cancer. In this study, we used such smart NPs to co-deliver paclitaxel (PTX) and siRNA against vascular endothelial growth factor (VEGF) gene for breast cancer therapy in mice models. For the prepared NPs, characterizations such as particle size, zeta potential, gel electrophoresis imaging and in vitro stability were investigated. Then, 4T1 cells were used to evaluate the in vitro VEGF silencing capacity, tumor cell inhibitory and anti-apoptotic abilities. Finally, an orthotopic model of mouse breast cancer was established to evaluate the in vivo antitumor effects and safety properties of PTX-siRNA^VEGF-NPs.

Results

We prepared PTX-siRNA^VEGF-NPs with particle size of 85.25 nm, PDI of 0.261, and zeta potential of 5.25 mV. The NPs with VEGF siRNA effectively knocked down the expression of VEGF mRNA. Cell counting kit-8 (CCK-8) and apoptosis assays revealed that the PTX-siRNA^VEGF-NPs exhibited antiproliferation effect of PTX on 4T1 cells. The in vivo anti-tumor study indicated that PTX-siRNA^VEGF-NPs could exert an antitumor effect by inhibiting the formation and development of new blood vessels in tumor tissues, thereby cutting off nutrient and blood supplies required for tumor tissue growth. Both the anti-tumor efficacy and in vivo safety of the PTX-siRNA^VEGF-NPs group were better than that of the PTX-NPs and siRNA^VEGF-NPs groups.

Conclusion

The combination of PTX and VEGF siRNA exerts good antitumor effect on 4T1 tumor cells. This study provides a theoretical and practical basis for breast cancer therapy.

Co-delivery of paclitaxel and anti-VEGF siRNA by tripeptide lipid nanoparticle to enhance the anti-tumor activity for lung cancer therapy

The combination of chemotherapeutic drug paclitaxel (PTX) and VEGF siRNA could inhibit cancer development with synergistic efficacy. However, efficient and safe delivery systems with high encapsulation efficiency of PTX and a long-time release of drugs are urgently needed. In this study, novel nanoparticles (PTX/siRNA/FALS) were constructed by using tripeptide lipid (L), sucrose laurate (S), and folate-PEG₂₀₀₀-DSPE (FA) to co-deliver PTX and siRNA. The cancer cell targeting nanoparticle carrier (PTX/siRNA/FALS) showed anticipated PTX encapsulation efficiency, siRNA retardation ability, improved cell uptake and sustained and controlled drug release. It led to significant anti-tumor activity in vitro and in vivo by efficient inhibition of VEGF expression and induction of cancer cell apoptosis. Importantly, the biocompatibility of the carriers and low dosage of PTX required for effective therapy greatly reduced the toxicity to mice. The targeting nanoparticles show potential as an effective co-delivery platform for RNAi and chemotherapy drugs, aiming to improve the efficacy of cancer therapy.

Co-delivery of VEGF siRNA and Etoposide for Enhanced Anti-angiogenesis and Anti-proliferation Effect via Multi-functional Nanoparticles for Orthotopic Non-Small Cell Lung Cancer Treatment

Targeting tumor angiogenesis pathway via VEGF siRNA (siVEGF) has shown great potential in treating highly malignant and metastatic non-small cell lung cancer (NSCLC). However, anti-angiogenic monotherapy lacked sufficient antitumor efficacy which suffered from malignant tumor proliferation. Therefore, the combined application of siVEGF and chemotherapeutic agents for simultaneous targeting of tumor proliferation and angiogenesis has been a research hotspot to explore a promising NSCLC therapy regimen.

Methods: We designed, for the first time, a rational therapy strategy via intelligently co-delivering siVEGF and chemotherapeutics etoposide (ETO) by multi-functional nanoparticles (NPs) directed against the orthotopic NSCLC. These NPs consisted of cationic liposomes loaded with siVEGF and ETO and then coated with versatile polymer PEGylated histidine-grafted chitosan-lipoic acid (PHCL). We then comprehensively evaluated the anti-angiogenic and anti-proliferation efficiency in the in vitro tumor cell model and in bioluminescent orthotopic lung tumor bearing mice model.

Results: The NPs co-delivering siVEGF and ETO exhibited tailor-made surface charge reversal features in mimicking tumor extracellular environment with improved internal tumor penetration capacity and higher cellular internalization. Furthermore, these NPs with flexible particles size triggered by intracellular acidic environment and redox environment showed pinpointed and sharp intracellular cargo release guaranteeing adequate active drug concentration in tumor cells. Enhanced VEGF gene expression silencing efficacy and improved tumor cell anti-proliferation effect were demonstrated in vitro. In addition, the PHCL layer improved the stability of these NPs in neutral environment allowing enhanced orthotopic lung tumor targeting efficiency in vivo. The combined therapy by siVEGF and ETO co-delivered NPs for orthotopic NSCLC simultaneously inhibited tumor proliferation and tumor angiogenesis resulting in more significant suppression of tumor growth and metastasis than monotherapy.

Conclusion: Combined application of siVEGF and ETO by the multi-functional NPs with excellent and on-demand properties exhibited the desired antitumor effect on the orthotopic lung tumor. Our work has significant potential in promoting combined anti-angiogenesis therapy and chemotherapy regimen for clinical NSCLC treatment.

Bioreducible branched poly(modified nona-arginine) cell-penetrating peptide as a novel gene delivery platform

Cell-penetrating peptides (CPPs) have been widely used to deliver nucleic acid molecules. Generally, CPPs consisting of short amino acid sequences have a linear structure, resulting in a weak complexation and low transfection efficacy. To overcome these drawbacks, a novel type of CPP is required to enhance the delivery efficacy while maintaining its safe use at the same time. Herein, we report that a bioreducible branched poly-CPP structure capable of responding to reducing conditions attained both outstanding delivery effectiveness and selective gene release in carcinoma cells. Branched structures provide unusually strong electrostatic attraction between DNA and siRNA molecules, thereby improving the transfection capability through a tightly condensed form. We designed a modified type of nona-arginine (mR9) and synthesized a branched-mR9 (B-mR9) using disulfide bonds. A novel B-mR9/pDNA polyplex exhibited redox-cleavability and high transfection efficacy compared to conventional CPPs, with higher cell viability as well. B-mR9/VEGF siRNA polyplex exhibited significant serum stability and high gene-silencing effects in vitro. Furthermore, the B-mR9 polyplex showed outstanding tumor accumulation and inhibition ability in vivo. The results suggest that the bioreducible branched poly CPP has great potential as a gene delivery platform.

A theranostic micelleplex co-delivering SN-38 and VEGF siRNA for colorectal cancer therapy

The development of an efficient colorectal cancer therapy is currently a public health priority. In the present work, we proposed a multifunctional theranostic micellar drug delivery system utilizing cationic PDMA-block-poly(ε-caprolactone) (PDMA-b-PCL) micelles as nanocarriers of SN-38 (7-ethyl-10-hydroxycamptothecin), ultra-small superparamagnetic iron oxide nanoparticles (USPIO), and small interfering RNA (siRNA) that targets human vascular endothelial growth factor (VEGF). The VEGF siRNA was conjugated to polyethylene glycol (PEG) (siRNA-PEG) before complexation with the micelles in order to improve the siRNA's stability and to prolong its retention time in the blood circulation. To further improve the in vivo biosafety, we prepared mixed micelles using mPEG-PCL together with PDMA-b-PCL copolymer. The SN-38/USPIO-loaded siRNA-PEG mixed micelleplexes passively targeted to tumor regions and synergistically facilitated VEGF silencing and chemotherapy, thus efficiently suppressing tumor growth via a multi-dose therapy regimen. Additionally, the SN-38/USPIO-loaded siRNA-PEG mixed micelleplexes acted as a negative magnetic resonance imaging (MRI) contrast agent in T2-weighted imaging, resulting in a powerful tool for the diagnosis and for tracking of the therapeutic outcomes. In summary, we established a theranostic micellar drug and gene delivery system that not only synergistically combined gene silencing and chemotherapy but also served as a negative MRI contrast agent, which reveal its potential as a novel colorectal cancer therapy.

Tumor targeting RGD conjugated bio-reducible polymer for VEGF siRNA expressing plasmid delivery

Targeted delivery of therapeutic genes to the tumor site is critical for successful and safe cancer gene therapy. The arginine grafted bio-reducible poly (cystamine bisacrylamide-diaminohexane, CBA-DAH) polymer (ABP) conjugated poly (amido amine) (PAMAM), PAM-ABP (PA) was designed previously as an efficient gene delivery carrier. To achieve high efficacy in cancer selective delivery, we developed the tumor targeting bio-reducible polymer, PA-PEG1k-RGD, by conjugating cyclic RGDfC (RGD) peptides, which bind αvβ3/5 integrins, to the PAM-ABP using polyethylene glycol (PEG, 1 kDa) as a spacer. Physical characterization showed nanocomplex formation with bio-reducible properties between PA-PEG1k-RGD and plasmid DNA (pDNA). In transfection assays, PA-PEG1k-RGD showed significantly higher transfection efficiency in comparison with PAM-ABP or PA-PEG1k-RAD in αvβ3/5 positive MCF7 breast cancer and PANC-1 pancreatic cancer cells. The targeting ability of PA-PEG1k-RGD was further established using a competition assay. To confirm the therapeutic effect, the VEGF siRNA expressing plasmid was constructed and then delivered into cancer cells using PA-PEG1k-RGD. PA-PEG1k-RGD showed 20-59% higher cellular uptake rate into MCF7 and PANC-1 than that of non-targeted polymers. In addition, MCF7 and PANC-1 cancer cells transfected with PA-PEG1k-RGD/pshVEGF complexes had significantly decreased VEGF gene expression (51-71%) and cancer cell viability (35-43%) compared with control. These results demonstrate that a tumor targeting bio-reducible polymer with an anti-angiogenic therapeutic gene could be used for efficient and safe cancer gene therapy.

Oral delivery of shRNA and siRNA via multifunctional polymeric nanoparticles for synergistic cancer therapy

Galactose modified trimethyl chitosan-cysteine (GTC) conjugates with various galactose grafting densities were developed for oral delivery of Survivin shRNA-expression pDNA (iSur-pDNA) and vascular endothelial growth factor (VEGF) siRNA (siVEGF) in the synergistic and targeted treatment of hepatoma. iSur-pDNA and siVEGF loaded GTC nanoparticles (NPs) were prepared via electrostatic complexation and showed desirable stability in physiological fluids and improved intestinal permeation compared to naked genes. Galactose grafting density of GTC NPs significantly affected their in vitro and in vivo antitumor activities. GTC NPs with moderate galactose grafting density, termed GTC2 NPs, were superior in facilitating cellular uptake, promoting nuclear distribution, and silencing target genes, leading to notable inhibition of cell growth. In tumor-bearing mice, orally delivered GTC2 NPs could effectively accumulate in the tumor tissues and silence the expression of Survivin and VEGF, evoking increased apoptosis, inhibited angiogenesis, and thus the most efficient tumor regression. Moreover, compared with single gene delivery, co-delivery of iSur-pDNA and siVEGF showed synergistic effects on inhibiting in vitro cell proliferation and in vivo tumor growth. This study could serve as an effective approach for synergistic cancer therapy via oral gene delivery, and highlighted the importance of ligand grafting density in the rational design of targeted nanocarriers.

Development of small interfering RNA delivery system using PEI-PEG-APRPG polymer for antiangiogenic vascular endothelial growth factor tumor-targeted therapy

Background

Small interfering RNA (siRNA) can silence target genes in the cytoplasm and be a major tool in gene therapy. Vascular endothelial growth factor (VEGF), a potent regulator of angiogenesis, is overexpressed in most tumors and is closely associated with tumor growth and metastasis. It has been shown that inhibition of VEGF expression by siRNA is an effective and useful method for antiangiogenic tumor therapy.

Methods

In the present study, we synthesized a targeted delivery system of PEI-PEG-APRPG incorporating angiogenic vessel-homing Ala-Pro-Arg-Pro-Gly (APRPG) peptide into cationic polyethylenimine (PEI) via a hydrophilic poly(ethylene glycol) (PEG) spacer.

Results

PEI-PEG-APRPG effectively condensed siRNA into 20–50 nm nanoparticles with a positive surface charge using a suitable N/P ratio. The siRNA/PEI-PEG-APRPG complex effectively enhanced the stability of siRNA in RNase A, and improved the proliferation-inhibiting ability and transfection efficiency of siRNA in vitro and tumor accumulation in vivo. In addition, the siRNA/PEI-PEG-APRPG complex exhibited high efficiency as antitumor therapy with regard to tumor growth, microvessel density, and VEGF protein and mRNA levels.

Conclusion

These findings suggest that PEI-PEG-APRPG effectively delivers siRNA to tumors overexpressing VEGF and thereby inhibits tumor growth.