A new acetylated triterpene saponin from Agrostemma githago L. modulates gene delivery efficiently and shows a high cellular tolerance

Standardization Approaches for Extracellular Vesicle Loading with Oligonucleotides and Biologics

Extracellular vesicles (EVs) are widely recognized for their potential as drug delivery systems. EVs are membranous nanoparticles shed from cells. Among their natural features are their ability to shield cargo molecules against degradation and enable their functional internalization into target cells. Especially biological or bio-inspired large molecules (LMs), like nucleic acids, proteins, peptides, and others, may profit from encapsulation in EVs for drug delivery purposes. In the last years, a variety of loading protocols are explored for different LMs. The lack of standardization in the EV drug delivery field has impeded their comparability so far. Currently, the first reporting frameworks and workflows for EV drug loading are proposed. The aim of this review is to summarize these evolving standardization approaches and set recently developed methods into context. This will allow for enhanced comparability of future work on EV drug loading with LMs.

Anti-angiogenic effects of aqueous extract from Agrostemma githago L. seed in human umbilical vein endothelial cells via regulating Notch/VEGF, MMP2/9, ANG2, and VEGFR2

Abnormal angiogenesis contributes to the pathogenesis of various diseases. The medicinal usage of Agrostemma githago L. seed (A. githago herein) has been stated in traditional medicine. This study aims to investigate the anti-angiogenic potential of aqueous extract of A. githago. In order to test the effect of A. githago extract, its impact on HUVECs, T98G, and HGF2PI2 cells was assessed by looking at cellular viability, changes in the distribution of cells in different phases of the cell cycle, induction of oxidative stress, and apoptosis. In addition, the release of VEGF, ANG2, and MMP2/9 factors, along with the expressions of the critical Notch signaling pathway players and VEGF receptors (VEGFR), was measured. Furthermore, a γ-secretase inhibitor (LY411575) was applied to determine whether Notch inhibition restores A. githago effects. As a further characterization, total phenolic and flavonoid contents of A. githago were estimated, and five triterpene saponin compounds were identified using LC-ESI-MS. In response to A. githago extract, a reduction in total cell viability, along with the induction of ROS and apoptosis, was detected. Exposure to the A. githago extract could modulate the release of VEGF and ANG2 from T98G and HUVECs, respectively. In addition, A. githago reduced the release of MMP2/9. Furthermore, Notch1, DLL4, and HEY2 transcripts and protein expressions were up-regulated, while VEGFR2 was down-regulated in treated HUVEC cells. Treatment with the A. githago extract resulted in a dose-dependent inhibition of AKT phosphorylation. Inhibition of Notch signaling retrieved the viability loss, reduced intracellular ROS, and alleviated the impaired tube formation in A. githago-treated HUVECs. Overall, these data underscore the anti-angiogenic potential of A. githago via inducing apoptosis, modifying the expression levels of VEGF/VEGFR2, and impacting the release of MMP2/9 and ANG2, effects that are most probably modulated through the Notch/VEGF signaling axis.

Saponin and fluorine-modified polycation as a versatile gene delivery system

Despite the development of many novel carriers for the delivery of various types of genetic material, the lack of a delivery system with high efficiency and low cytotoxicity is a major bottleneck. Herein, low molecular weight polyethylenimine (PEI_1.8k) was functionalized with saponin residues using phenylboronic acid (PBA) as an ATP-responsive cross-linker, and a fluorinated side chain to construct PEI-PBA-SAP-F polycation as a highly efficient delivery vector. This vehicle could transfect small plasmid DNA (∼3 kb) with outstanding efficiency into various cells, including HEK 293T, NIH3T3, A549, PC12, MCF7 and HT-29, as well as robust transfection of a large plasmid (∼9 kb) into HEK 293T cells. The carrier indicated good transfection efficacy even at high concentration of serum and low doses of plasmid. The use of green fluorescent protein (GFP) knock-out analysis demonstrated transfection of different types of CRISPR/Cas9 complexes (Cas9/sgRNA ribonucleoproteins RNP, plasmid encoding Cas9 plus sgRNA targeting GFP, Cas9 expression plasmid plusin vitro-prepared sgRNA). In summary, we report an effective PEI-PBA-SAP-F gene carrier with the appropriate lipophilic/cationic balance for biomedical applications.

Suicide nanoplasmids coding for ribosome-inactivating proteins

Conventional eukaryotic expression plasmids contain a DNA backbone that is dispensable for the cellular expression of the transgene. In order to reduce the vector size, minicircle DNA technology was introduced. A drawback of the minicircle technology are considerable production costs. Nanoplasmids are a relatively new class of mini-DNA constructs that are of tremendous potential for pharmaceutical applications. In this study we have designed novel suicide nanoplasmid constructs coding for plant derived ribosome-inactivating proteins. The suicide-nanoplasmids were formulated with a targeted K16-lysine domain, analyzed for size, and characterized by electron microscopy. The anti-proliferative activity of the suicide-nanoplasmids was investigated in vitro by real time microscopy and the expression kinetic was determined using an enhanced green fluorescent protein nanoplasmid variant. In an aggressive in vivo neuroblastoma tumor model, treated mice showed a reduced tumor growth whereby the therapy was well tolerated.

Construction of Minicircle Suicide Genes Coding for Ribosome-Inactivating Proteins

Due to the lower risks of adverse effects, nonviral gene therapy is a suitable alternative to transfect cancer cells with a suicide gene to let them kill themselves by expressing toxic ribosome-inactivating proteins. Plasmids are stable and easy-to-produce vectors, but they have some disadvantages due to the bacterial backbone. Applying the minicircle technology, this problem can be solved with manageable effort in a well-equipped laboratory. With the described methodology, minicircle-DNA can be produced at low costs. The cell killing properties are monitored following transfection using the CytoSMART^® Omni system-a camera based live cell imaging device.