Endothelial cell-targeted pVEGF165 polyplex plays a pivotal role in inhibiting intimal thickening after vascular injury

Lipid Nanoparticles for Nucleic Acid Delivery to Endothelial Cells

Endothelial cells play critical roles in circulatory homeostasis and are also the gateway to the major organs of the body. Dysfunction, injury, and gene expression profiles of these cells can cause, or are caused by, prevalent chronic diseases such as diabetes, cardiovascular disease, and cancer. Modulation of gene expression within endothelial cells could therefore be therapeutically strategic in treating longstanding disease challenges. Lipid nanoparticles (LNP) have emerged as potent, scalable, and tunable carrier systems for delivering nucleic acids, making them attractive vehicles for gene delivery to endothelial cells. Here, we discuss the functions of endothelial cells and highlight some receptors that are upregulated during health and disease. Examples and applications of DNA, mRNA, circRNA, saRNA, siRNA, shRNA, miRNA, and ASO delivery to endothelial cells and their targets are reviewed, as well as LNP composition and morphology, formulation strategies, target proteins, and biomechanical factors that modulate endothelial cell targeting. Finally, we discuss FDA-approved LNPs as well as LNPs that have been tested in clinical trials and their challenges, and provide some perspectives as to how to surmount those challenges.

A cationic cyclodextrin derivative-lipid hybrid nanoparticles for gene delivery effectively promotes stability and transfection efficiency

Genetic medicines hold great promise for treatment of a number of diseases, however, the development of effective gene delivery carrier is still a challenge. The commonly used gene carrier liposomes and cationic polymers have limited their clinical application due to their respective disadvantages. Lipid-polymer hybrid nanoparticles (LHNPs) are novel drug delivery system which exhibit complementary characteristics of both polymeric nanoparticles and liposomes. In this account, we developed the α-cyclodextrin conjugated generation-2 polyamidoamine dendrimers-lipids hybrid nanoparticles (CDG2-LHNPs) for gene delivery. The pDNA/CDG2-LHNPs was stable during 15 days storage period both at 4 °C, 25 °C and 37 °C, whereas the particle size of pDNA/CDG2 and pDNA/liposomes dramatically increased after storage at 4 °C for 8 h. CDG2-LHNPs showed significantly superior transfection efficiencies compared to either CDG2 or liposomes. The mechanism of high transfection efficiency of pDNA/CDG2-LHNPs was further explored using pharmacological inhibitors chlorpromazine, filipin and cytochalasion D. The result demonstrated that cell uptake of pDNA/CDG2-LHNPs was mediated by clathrin-mediated endocytosis (CME), caveolae-mediated endocytosis (CvME) and macropinocytosis together. pDNA/CDG2-LHNPs were more likely be taken up by cells through C_VME, which avoided lysosomal degradation to a large extent. Moreover, the liposome component of pDNA/CDG2-LHNPs increased its cell uptake efficiency, and the CDG2 polymer component increased its proton buffer capacity, so the hybrid nanoparticles taken up by CME could also successfully escape from the lysosome. This CDG2-LHNPs with stability and high transfection efficiency overcome the shortcomings of liposomes and polymers applied separately, and has great potential for gene drug delivery.

Melatonin attenuates smoking-induced atherosclerosis by activating the Nrf2 pathway via NLRP3 inflammasomes in endothelial cells

Substantial evidence suggests that the effects of smoking in atherosclerosis are associated with inflammation mediated by endothelial cells. However, the mechanisms and potential drug therapies for smoking-induced atherosclerosis remain to be clarified. Considering that melatonin exerts beneficial effects in cardiovascular diseases, we examined its effects on cigarette smoke-induced vascular injury. We found that cigarette smoke extract (CSE) treatment induced NLRP3-related pyroptosis in human aortic endothelial cells (HAECs). CSE also induced ROS generation and upregulated the Nrf2 pathway in HAECs. Furthermore, pretreatment of HAECs with Nrf2-specific siRNA and an Nrf2 activator revealed that Nrf2 can inhibit CSE-induced ROS/NLRP3 activation. Nrf2 also improved cell viability and the expression of VEGF and eNOS in CSE-treated HAECs. In balloon-induced carotid artery injury model rats exposed to cigarette smoke, melatonin treatment reduced intimal hyperplasia in the carotid artery. Mechanistic studies revealed that compared with the control group, Nrf2 activation was increased in the melatonin group, whereas ROS levels and the NLRP3 inflammasome pathway were inhibited. These results reveal that melatonin might effectively protect against smoking-induced vascular injury and atherosclerosis through the Nrf2/ROS/NLRP3 signaling pathway. Overall, these observations provide compelling evidence for the clinical use of melatonin to reduce smoking-related inflammatory vascular injury and atherosclerosis.

Cyclic RGD Peptide Targeting Coated Nano Drug Co-Delivery System for Therapeutic Use in Age-Related Macular Degeneration Disease

Vascular endothelial growth factor (VEGF) expression increased significantly in the pathogenesis of age-related macular degeneration, which induced the formation of pathological blood vessels. Dexamethasone is an exogenous anti-angiogenic drug while bevacizumab is an endogenous anti-angiogenic drug. They both have been widely used in ophthalmology. However, independent administration is not enough to completely block the development of choroidal neovascularization (CNV), and the number of eyes vitreous injections is limited. Reasonable combination of drugs may produce significantly better therapeutic effect than single drug treatment. The cyclic RGD (cRGD) peptide has a particularly high affinity with retinal pigment epithelial cells, where VEGF secretes from. In this study, we prepared nanoparticles of bevacizumab and dexamethasone with cRGD peptide as the target (aBev/cRGD-DPPNs). The particle size of the aBev/cRGD-DPPNs was 213.8 ± 1.5 nm, SEM results showed that the nano-carriers were well dispersed and spherical. The cell uptake study demonstrated the selectivity of the aBev/cRGD-DPPN to ARPE-19 with α_Vβ₃ over expressed. The aBev/cRGD-DPPNs had a better apoptosis induction effect and an obvious inhibitory effect on migration, invasion, and capillary-like structures formation of human umbilical vein epithelial cells. The fluorescein fundus angiography study, immunohistochemistry and histopathological evaluation showed the aBev/cRGD-DPPNs greatly reduced the development of CNV on a rabbit model.

Robust Photodynamic Therapy Using 5-ALA-Incorporated Nanocomplexes Cures Metastatic Melanoma through Priming of CD4+CD8+ Double Positive T Cells

Advanced melanoma can rarely be cured. Photodynamic therapy (PDT) readily eradicates the primary melanoma but has limited ability to destroy the spreading tumor cells unless supported by other combinative interventions to augment systemic antitumor immunity. Based on the previously synthesized penetration-enhancing biomaterials, a topically administered nanoformulation is developed, which profoundly assists 5-aminolevulinic acid (5-ALA) in circumventing skin barrier to be selectively delivered to tumor cells. After endocytosis, accumulated 5-ALA is efficiently metabolized to a photosensitizer protoporphyrin IX (PpIX) which stimulates a large production of cytotoxic reactive oxygen species (ROS) under illumination. Accompanied by the robust inflammatory responses followed by primary tumor destruction, CD4+CD8+ double positive T cells are highly boosted to harness host immunity to purge metastases in lymphoid organs. Compared with dacarbazine and programmed death 1 (PD-1) antibody, this treatment in advanced melanoma murine models, achieves a striking curable rate of 90% without melanoma prognostic markers LDH and S-100B detection, followed by a relapse-free survival rate of 83.33% in 300 days. Moreover, the cured mice's immune system function recovers to an extent similar to healthy mice without prolonged or exaggerated inflammation. This study using the synergistic biomaterials approach may thus render 5-ALA-mediated PDT a potentially curative therapy for advanced melanoma in clinic.

Overexpression of Hepatocyte Growth Factor mRNA Induced by Gene Transfer Attenuates Neointimal Hyperplasia After Balloon Injury

Hepatic growth factor (HGF) has been widely used in studies on arterial remodeling after injury, and results turn out to be inconsistent. The changes of endogenous HGF expression after injury also remain controversial. This study clarified the role of exogenous human HGF (hHGF) gene transfer in neointimal hyperplasia and investigated the associated alterations of endogenous HGF and c-Met expressions under endothelial denudation with or without hHGF gene transfer using a balloon-injured rabbit aorta model. Sixty-one rabbits were randomly divided into normal controls, endothelial injury, endothelial injury with hHGF, or the control vector gene transfer groups. On weeks 1, 2, 4, and 8 after injury, neointimal hyperplasia and endothelialization were evaluated by the ratio of neointimal area to medial area (N/M ratio), CD31-positive staining, α-smooth muscle actin, and endothelial nitric oxide synthase expressions using histological analysis, immunohistochemistry staining, or real-time quantitative reverse transcriptase polymerase chain reaction. Endogenous rabbit HGF (rHGF) and c-Met expressions were detected with immunohistochemistry staining and quantitative reverse transcriptase polymerase chain reaction. It was found that expressions of endogeneous rHGF and c-Met in endothelial injury upregulated with peak levels on week 2 or week 4 after injury (p < 0.01). On week 1 after hHGF transfer, neointimal hyperplasia was significantly inhibited (p < 0.001), with decreased α-smooth muscle actin expression (p < 0.05) and improved endothelial cells regeneration and function (p < 0.01). More remarkable overexpression of endogenous rHGF and c-Met mRNAs were detected, and lowered positive staining of rHGF and c-Met was shown in the neointima (p < 0.05). These results demonstrated hHGF gene transfer induced further overexpression of endogenous rHGF and c-Met mRNAs but lowered immunoreactivities of rHGF and c-Met in the neointima, thus leading to significant attenuation of neointimal hyperplasia.