A new class of polyphenolic carbosilane dendrimers binds human serum albumin in a structure-dependent fashion

The use of dendrimers as drug and nucleic acid delivery systems requires knowledge of their interactions with objects on their way to the target. In the present work, we investigated the interaction of a new class of carbosilane dendrimers functionalized with polyphenolic and caffeic acid residues with human serum albumin, which is the most abundant blood protein. The addition of dendrimers to albumin solution decreased the zeta potential of albumin/dendrimer complexes as compared to free albumin, increased density of the fibrillary form of albumin, shifted fluorescence spectrum towards longer wavelengths, induced quenching of tryptophan fluorescence, and decreased ellipticity of circular dichroism resulting from a reduction in the albumin α-helix for random coil structural form. Isothermal titration calorimetry showed that, on average, one molecule of albumin was bound by 6-10 molecules of dendrimers. The zeta size confirmed the binding of the dendrimers to albumin. The interaction of dendrimers and albumin depended on the number of caffeic acid residues and polyethylene glycol modifications in the dendrimer structure. In conclusion, carbosilane polyphenolic dendrimers interact with human albumin changing its structure and electrical properties. However, the consequences of such interaction for the efficacy and side effects of these dendrimers as drug/nucleic acid delivery system requires further research.

Synthesis and biophysical evaluation of carbosilane dendrimers as therapeutic siRNA carriers

Gene therapy presents an innovative approach to the treatment of previously incurable diseases. The advancement of research in the field of nanotechnology has the potential to overcome the current limitations and challenges of conventional therapy methods, and therefore to unlocking the full potential of dendrimers for use in the gene therapy of neurodegenerative disorders. The blood-brain barrier (BBB) poses a significant challenge when delivering therapeutic agents to the central nervous system. In this study, we investigated the biophysical properties of dendrimers and their complexes with siRNA directed against the apolipoprotein E (APOE) gene to identify an appropriate nanocarrier capable of safely delivering the cargo across the BBB. Our study yielded valuable insights into the complexation process, stability over time, the mechanisms of interaction, the influence of dendrimers on the oligonucleotide's spatial structure, and the potential cytotoxic effects on human cerebral microvascular endothelium cells. Based on our findings, we identified that the dendrimer G3Si PEG6000 was an optimal candidate for further research, potentially serving as a nanocarrier capable of safely delivering therapeutic agents across the BBB for the treatment of neurodegenerative disorders.

I-CBP112 declines overexpression of ATP-binding cassette transporters and sensitized drug-resistant MDA-MB-231 and A549 cell lines to chemotherapy drugs

Despite extensive efforts and ongoing progress in personalized anticancer approaches, chemotherapy remains the first line or the only treatment for some tumors that may develop resistance to chemotherapeutics in time due to inter alia overexpression of ATP-binding cassette transporters. Using clinically-relevant resistant models of triple negative breast cancer (MDA-MB-231; TNBC) as well as non-small cell lung cancer (A549; NSCLC), we tested the efficacy of I-CBP112 - CBP/EP300 bromodomain inhibitor to overcome drug resistance by declining ABC gene transcription. I-CBP112 significantly reduced ABCB1, ABCC1, ABCC2, ABCC3, ABCC5 and ABCG2 in all resistant lines, as well as ABCC10 in TNBC and ABCC4 in paclitaxel-resistant NSCLC, thereby increasing intracellular drug accumulation and cytotoxicity in 2D and 3D cultures. This was phenocopied only by the joint effect of ABC inhibitors such as tariquidar (ABCB1 - P-glycoprotein and ABCG2) and MK-571 (ABCC), whereas single inhibition of ABCB1/ABCG2 or ABCC proteins did not affect drug accumulation, thereby implying the need of simultaneous deficiency in activity of majority of drug pumps for enhanced drug retention. I-CBP112 failed to directly inhibit activity of ABCB1, ABCG2 and ABCC subfamily members at the same time. Importantly, I-CBP112 treated cancer cells polarized human macrophages into proinflammatory phenotypes. Moreover, I-CBP112 remained non-toxic to primary cell lines, nor did it enhance anticancer drug toxicity to blood-immune cells. In silico assay of ADMET properties confirmed the desired pharmacokinetic features of I-CBP112. The results suggest that the CBP/p300 inhibitor is a promising co-adjuvant to chemotherapy in drug-resistant cancer phenotypes, capable of decreasing ABC transporter expression.

Ruthenium metallodendrimer against triple-negative breast cancer in mice

Carbosilane metallodendrimers, based on the arene Ru(II) complex (CRD13) and integrated to imino-pyridine surface groups have been investigated as an anticancer agent in a mouse model with triple-negative breast cancer. The dendrimer entered into the cells efficiently, and exhibited selective toxicity for 4T1 cells. In vivo investigations proved that a local injection of CRD13 caused a reduction of tumour mass and was non-toxic. ICP analyses indicated that Ru(II) accumulated in all tested tissues with a greater content detected in the tumour.

Lipid-coated ruthenium dendrimer conjugated with doxorubicin in anti-cancer drug delivery: Introducing protocols

One of the major limitations for the treatment of many diseases is an inability of drugs to cross the cell membrane barrier. Different kinds of carriers are being investigated to improve drug bioavailability. Among them, lipid or polymer-based systems are of special interest due to their biocompatibility. In our study, we combined dendritic and liposomal carriers and analysed the biochemical and biophysical properties of these formulations. Two preparation methods of Liposomal Locked-in Dendrimers (LLDs) systems have been established and compared. Carbosilane ruthenium metallodendrimer was complexed with an anti-cancer drug (doxorubicin) and locked in a liposomal structure, using both techniques. The LLDs systems formed by hydrophilic locking had more efficient transfection profiles and interacted with the erythrocyte membrane better than systems using the hydrophobic method. The results indicate these systems have improved transfection properties when compared to non-complexed components. The coating of dendrimers with lipids significantly reduced their hemotoxicity and cytotoxicity. The nanometric size, low polydispersity index and reduced positive zeta potential of such complexes made them attractive for future application in drug delivery. The formulations prepared by the hydrophobic locking protocol were not effective and will not be considered furthermore as prospective drug delivery systems. In contrast, the formulations formed by the hydrophilic loading method have shown promising results where the cytotoxicity of LLD systems with doxorubicin was more effective against cancer than normal cells.

The effect of novel tyrosine-modified polyethyleneimines on human albumin structure - Thermodynamic and spectroscopic study

The interaction of proteins with nanoparticle components are crucial for the evaluation of nanoparticle function, toxicity and biodistribution. Polyethyleneimines (PEIs) with defined tyrosine modifications are a class of novel polymers designed for improved siRNA delivery. Their interactions with biomacromolecules are still poorly described. This paper analyzes the interaction of different tyrosine-modified PEIs with human serum albumin as the most abundant serum protein. The ability of tyrosine modified, linear or branched PEIs to bind human serum albumin (HSA) was analyzed and further characterized. The interaction with hydrophobic parts of protein were studied using 1- nilinonaphthalene-8-sulfonic acid (ANS) and changes in the HSA secondary structure were evaluated using circular dichroism (CD). Complex formation and sizes were studied by transmission electron microscopy (TEM) and dynamic light scattering methods (DLS). We demonstrate that tyrosine modified PEIs are able to bind human serum albumin. Based on thermodynamic studies, van der Waals interaction, H-bonding and hydrophobic interactions are determined as main molecular forces involved in complex formation. Analysis of secondary structures revealed that the polymers decreased α-helix content, while increasing levels of randomly folded structures. Complex formation was confirmed by TEM and DLS. These findings are crucial for understanding polymer-protein interactions and the properties of nanoparticles.

Pegylated Gold Nanoparticles Conjugated with siRNA: Complexes Formation and Cytotoxicity

Drug delivery systems such as dendrimers, liposomes, polymers or gold/silver nanoparticles could be used to advance modern medicine. One significant pharmacological problem is crossing biological barriers by commonly used drugs, e.g., in the treatment of neurodegenerative diseases, which have a problem of the blood-brain barrier (BBB) restricting drug delivery. Numerous studies have been conducted to find appropriate drug carriers that are safe, biocompatible and efficient. In this work, we evaluate pegylated gold nanoparticles AuNP14a and AuNP14b after their conjugation with therapeutic siRNA directed against APOE4. This genetic risk factor remains the strongest predictor for late-onset Alzheimer’s disease. The study aimed to assess the biophysical properties of AuNPs/siAPOE complexes and to check their biological safety on healthy cells using human brain endothelial cells (HBEC-5i). Techniques such as fluorescence polarization, circular dichroism, dynamic light scattering, ζ-potential measurements and gel retardation assay showed that AuNPs form stable complexes with siRNA. Subsequently, cytotoxicity assays proved the biological safety of formed conjugates. Obtained results enabled us to find effective concentrations of AuNPs when complexes are formed and non-toxic for healthy cells. One of the studied nanoparticles, AuNP14b complexed with siRNA, displayed lower cytotoxicity (MTT assay, cells viability −74.8 ± 3.1%) than free nanoparticles (44.7 ± 3.6%). This may be promising for further investigations in nucleic acid delivery and could have practical use in treating neurodegenerative diseases.

Carbosilane ruthenium metallodendrimer as alternative anti-cancer drug carrier in triple negative breast cancer mouse model: A preliminary study

The carbosilane metallodendrimer G₁-[[NCPh(o-N)Ru(η6- p-cymene)Cl]Cl]₄ (CRD13), based on an arene Ru(II) complex coordinated to imino-pyridine surface groups, has been conjugated with anti-cancer drugs. Ruthenium in the positively-charged dendrimer structure allows this nanoparticle to be considered as an anticancer drug carrier, made more efficient because ruthenium has anticancer properties. The ability of CRD13 to form complexes with Doxorubicin (DOX), 5-Fluorouracil (5-Fu), and Methotrexate (MTX) has been evaluated using zeta potential measurement, transmission electron microscopy (TEM) and computer simulation. The results show that it forms stable nanocomplexes with all those drugs, enhancing their effectiveness against MDA-MB-231 cancer cells. In vivo tests indicate that the CRD13/DOX system caused a decrease of tumor weight in mice with triple negative breast cancer. However, the tumors were most visibly reduced when naked dendrimers were injected.

Combination of Copper Metallodendrimers with Conventional Antitumor Drugs to Combat Cancer in In Vitro Models

Copper carbosilane metallodendrimers containing chloride ligands and nitrate ligands were mixed with commercially available conventional anticancer drugs, doxorubicin, methotrexate and 5-fluorouracil, for a possible therapeutic system. To verify the hypothesis that copper metallodendrimers can form conjugates with anticancer drugs, their complexes were biophysically characterized using zeta potential and zeta size methods. Next, to confirm the existence of a synergetic effect of dendrimers and drugs, in vitro studies were performed. The combination therapy has been applied in two cancer cell lines: MCF-7 (human breast cancer cell line) and HepG2 (human liver carcinoma cell line). The doxorubicin (DOX), methotrexate (MTX) and 5-fluorouracil (5-FU) were more effective against cancer cells when conjugated with copper metallodendrimers. Such combination significantly decreased cancer cell viability when compared to noncomplexed drugs or dendrimers. The incubation of cells with drug/dendrimer complexes resulted in the increase of the reactive oxygen species (ROS) levels and the depolarization of mitochondrial membranes. Copper ions present in the dendrimer structures enhanced the anticancer properties of the whole nanosystem and improved drug effects, inducing both the apoptosis and necrosis of MCF-7 (human breast cancer cell line) and HepG2 (human liver carcinoma cell line) cancer cells.

Biophysical interactions of mixed lipid-polymer nanoparticles incorporating curcumin: Potential as antibacterial agent

The technology of lipid nanoparticles has a long history in drug delivery, which begins with the discovery of liposomes by Alec D Bangham in the 1960s. Since then, numerous studies have been conducted on these systems, and several nanomedicinal products that utilize them have entered the market, with the latest being the COVID-19 vaccines. Despite their success, many aspects of their biophysical behavior are still under investigation. At the same time, their combination with other classes of biomaterials to create more advanced platforms is a promising endeavor. Herein, we developed mixed lipid-polymer nanoparticles with incorporated curcumin as a drug delivery system for therapy, and we studied its interactions with various biosystems. Initially, the nanoparticle physicochemical properties were investigated, where their size, size distribution, surface charge, morphology, drug incorporation and stability were assessed. The incorporation of the drug molecule was approximately 99.8 % for a formulated amount of 10 % by weight of the total membrane components and stable in due time. The association of the nanoparticles with human serum albumin and the effect that this brings upon their properties was studied by several biophysical techniques, including light scattering, thermal analysis and circular dichroism. As a biocompatibility assessment, interactions with erythrocyte membranes and hemolysis induced by the nanoparticles were also studied, with empty nanoparticles being more toxic than drug-loaded ones at high concentrations. Finally, interactions with bacterial membrane proteins of Staphylococcus aureus and the antibacterial effect of the nanoparticles were evaluated, where the effect of curcumin was improved when incorporated inside the nanoparticles. Overall, the developed mixed nanoparticles are promising candidates for the delivery of curcumin to infectious and other types of diseases.

Comparison of tyrosine-modified low molecular weight branched and linear polyethylenimines for siRNA delivery

Polyethylenimines (PEIs) have been previously introduced for siRNA delivery. In particular, in the case of higher molecular weight PEIs, this is associated with toxicity, while low molecular weight PEIs are often insufficient for siRNA complexation. The tyrosine-modification of PEIs has been shown to enhance PEI efficacy and biocompatibility. This paper evaluates a set of tyrosine-modified low molecular weight linear or branched polyethylenimines as efficient carriers of siRNA. Complexation efficacies and biophysical complex properties were analyzed by zeta potential, dynamic light scattering and circular dichroism measurements as well as gel electrophoresis. Biological knockdown was studied in 2 D cell culture and 3 D ex vivo tissue slice air-liquid interface culture. The results demonstrate that siRNAs were able to form stable complexes with all tested polymers. Complexation was able to protect siRNA from degradation by RNase and to mediate target gene knockdown, as determined on the mRNA level and in PC3-Luc3/EGFP and HCT116-Luc3/EGFP expressing reporter cells on the protein level, using flow cytometry and confocal microscopy. The direct comparison of the studied polymers revealed differences in biological efficacies. Moreover, the tyrosine-modified PEIs showed high biocompatibility, as determined by LDH release and mitochondria integrity (J-aggregate assay) as well as caspase 3/7 (apoptosis) and H₂O₂ levels (ROS). In 3 D tissue slices, complexes based on LP10Y proved to be most efficient, by combining tissue penetration with efficient gene expression knockdown.

Unmodified and tyrosine-modified polyethylenimines as potential carriers for siRNA: Biophysical characterization and toxicity

Polyethylenimines (PEIs) are being explored as efficient non-viral nanocarriers for nucleic acid delivery in vitro and in vivo. To address limitations regarding PEI efficacy and biocompatibility, modifications of the chemical structure of linear and branched PEIs have been introduced, including grafting with tyrosine. The aim has been to compare linear and branched polyethylenimines of a wider range of different molecular mass with their tyrosine-modified derivatives. To do so, physico-chemical and biological properties of the polymers were investigated. Even in the absence of a negatively charged nucleic acid counterpart, PEIs form particle structures with defined size and surface potential. Tyrosine modification of PEI led to significantly reduced toxicity, while simultaneously increasing interaction with cellular membranes. All the effects were also dependent on the PEI molecular weight and structure (i.e., linear vs. branched). Especially in the case of linear PEIs, the improved membrane interaction also translated into slightly enhanced hemolysis, whereas their genotoxic potential was essentially abolished. Due to the improvement of properties critical for nano-vector efficacy and biocompatibility, our data demonstrate that tyrosine-modified PEIs are very promising and safe nanocarriers for the delivery of small RNAs, like siRNAs and miRNAs.

Nanoparticles for local delivery of siRNA in lung therapy

An overview of the application of natural and synthetic, non-viral vectors for oligonucleotide delivery into the lung is presented in this review, with a special focus on lung cancer. Due to the specificity of the respiratory tract, its structure and natural barriers, the administration of drugs (especially those based on nucleic acids) is a particular challenge. Among widely tested non-viral drug and oligonucleotides carriers, synthetic polymers seem to be most promising. Unique properties of these nanoparticles allow for essentially unlimited possibilities regarding their design and modification. This gives hope that optimal nanoparticles with ideal nucleic acid carrier properties for lung cancer therapy will eventually emanate.

Protein kinases as therapeutic targets to develop anticancer drugs with natural alkaloids

Backgroud: Protein kinases play an important role in cell proliferation, differentiation, mobility and cell cycle arrest etc. These enzymes act as important targets in developing anticancer agents. Over the years, a large number of protein kinase inhibitors have been discovered and developed as anticancer agents for the treatment of cancers clinically. However, the drug-resiatance and off-targeting limit their effeciancy for the treatment of human cancer. Materials and methods: Alkaloids are an important class of natural products with broad spectrum biological activities. In the past decades, numerus alkaloids with significant anticancer activity by inhibiting protein kinases were identified. In the present mini-review, we will present the key enzymes including mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) and janus-activated kinases/signal transducer and activator of transcription (JAK/STAT) targeted by alkaloids and highlight the special sites targeted by alkaloids on protein kinases and/or reversing drug resistance. Additionally, the challenge and prospect of developing alkaloids as new anticancer agents are also discussed. Conclusion: Alkaloids suppressed tumor growth through targeting different signaling pathways mediated by protein kinases of cancer cells. It is conceivable that novel alkaloids anticancer agents with promising clinical value will be developed in the future.

Renal denervation in truly resistant hypertensive patients: six-year follow-up results of a single-center study

Background

Renal sympathetic denervation (RDN) is one of the invasive treatment options for the patients with hypertension (HTN) who are resistant to antihypertensive therapy (AHT). The short-term efficacy of RDN has been proven in a number of randomized clinical trials, but remains controversial, the data on its long-term efficacy are limited.

Purpose

To evaluate the natural course of HTN, to assess long-term major adverse cardiovascular events (MACEs) and other clinically significant outcomes, as well as AHT efficacy and its features in patients with truly resistant HTN after bilateral RDN during extended prospective follow-up.

Methods

We included 22 patients with truly resistant HTN (median 57 y.o., 9 males), in whom RDN was performed during 2012–2015 in the clinical center of excellence. We assessed initial and further (after 1 year and after ≥5 years) office and 24-hour BP values, as well as AHT history in detail. Long-term MACEs and other cancer-related outcomes were recorded. The baseline quality of life (QoL) and its dynamics were assessed with the use of EQ-5D-5L questionnaire at all timepoints. Multiple linear regression was used to find possible predictors of the efficacy of RDN.

Results

The median follow-up after the RDN was 6 (from 5 to 8) years. A significant decrease in office and 24-hour systolic (S) and diastolic BPs was observed at 12 months after RDN compared to initial values (Δ −24 and −12 mm Hg, p<0.005; Δ −10 and −7 mm Hg, p<0.05, respectively). There were 7 patients with office SBP on-target (<140 mm Hg), and 12 patients were considered responders (SBP decrease more than 10 mm Hg from the baseline). These numbers increased to 10 and 14 patients after 6 years after RDN, respectively. A causal relationship between changes in office SBP was found only for SBP baseline values (β −0.6, p=0.02). No differences in the number of medications were noted during follow-up (4.4 versus 4.1 versus 4.1 drugs, p=0.41). We have recorded 10 MACEs and 5 cancer cases with various types with no fatal outcomes. The QoL significantly improved at 12 months after RDN (+9.7 points, p=0.01), however a negative trend was observed in the next 6 years (−13,8 points, p=0,02) with return to the reference. No association was observed between BP and QoL changes in two timepoints (p=0,65).

Conclusions

The RDN shows a pronounced clinical effect in patients with resistant HTN up to 6 years, and is not accompanied by an AHT intensification, and also is not associated with QoL changes. The initial positive trend for QoL completely harked back after 5 years which may be associated with the development of MACEs. The only predictor of RDN positive effect seems to be baseline office SBP levels.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Russian Science Foundation Study flow-chartChanges in BPs during follow-up

Dendrimeric HIV-peptide delivery nanosystem affects lipid membranes structure

The aim of this study was to evaluate the nature and mechanisms of interaction between HIV peptide/dendrimer complexes (dendriplex) and artificial lipid membranes, such as large unilayered vesicles (LUV) and lipid monolayers in the air-water interface. Dendriplexes were combined as one of three HIV-derived peptides (Gp160, P24 and Nef) and one of two cationic phosphorus dendrimers (CPD-G3 and CPD-G4). LUVs were formed of 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC) or of a mixture of DMPC and dipalmitoyl-phosphatidylglycerol (DPPG). Interactions between dendriplexes and vesicles were characterized by dynamic light scattering (DLS), fluorescence anisotropy, differential scanning calorimetry (DSC) and Langmuir-Blodgett methods. The morphology of formed systems was examined by transmission electron microscopy (TEM). The results suggest that dendriplexes interact with both hydrophobic and hydrophilic regions of lipid bilayers. The interactions between dendriplexes and negatively charged lipids (DMPC-DPPG) were stronger than those between dendriplexes and liposomes composed of zwitterionic lipids (DMPC). The former were primarily of electrostatic nature due to the positive charge of dendriplexes and the negative charge of the membrane, whereas the latter can be attributed to disturbances in the hydrophobic domain of the membrane. Obtained results provide new information about mechanisms of interaction between lipid membranes and nanocomplexes formed with HIV-derived peptides and phosphorus dendrimers. These data could be important for the choosing the appropriate antigen delivery vehicle in the new vaccines against HIV infection.

Organometallic dendrimers based on Ruthenium(II) N-heterocyclic carbenes and their implication as delivery systems of anticancer small interfering RNA

With the purpose of obtaining a new dendritic system against cancer, this paper is focused on the synthesis of spherical carbosilane metallodendrimers of different generations holding Ru(II) N-heterocyclic carbene (NHC) on the periphery from the imidazolium precursors. Both imidazolium salt dendrimers and their metallodendrimers counterparts showed promising anticancer activity, similar to cisplatin, mainly at high generations. In addition, both families of second and third generations were able to form dendriplexes with anticancer small interfering RNA (siRNA), protecting the cargo against RNAse and being able to internalize it in HEPG2 (human liver cancer) tumour cells. The characterization and effectiveness of the dendriplexes were evaluated by various analytical techniques such as zeta potential, electrophoresis and circular dichroism, the stability of the system and the protective nature of the dendrimer estimated using RNAse and the internalization of dendriplexes by confocal microscopy. The major advantage observed with the ruthenium metallodendrimers with respect to the imidazolium salts precursors was in cellular uptake, where the internalization of Mcl-1-FITC siRNA (myeloid cell leukaemia-1 fluorescein labelled siRNA) proceeded more efficiently. Therefore, we propose here that both imidazolium and Ru metallodendrimers are interesting candidates in cancer due to their double action, as anticancer per se and as carrier for anticancer siRNA, providing in this way a combined action.

Chimeric Stimuli-Responsive Liposomes as Nanocarriers for the Delivery of the Anti-Glioma Agent TRAM-34

Nanocarriers are delivery platforms of drugs, peptides, nucleic acids and other therapeutic molecules that are indicated for severe human diseases. Gliomas are the most frequent type of brain tumor, with glioblastoma being the most common and malignant type. The current state of glioma treatment requires innovative approaches that will lead to efficient and safe therapies. Advanced nanosystems and stimuli-responsive materials are available and well-studied technologies that may contribute to this effort. The present study deals with the development of functional chimeric nanocarriers composed of a phospholipid and a diblock copolymer, for the incorporation, delivery and pH-responsive release of the antiglioma agent TRAM-34 inside glioblastoma cells. Nanocarrier analysis included light scattering, protein incubation and electron microscopy, and fluorescence anisotropy and thermal analysis techniques were also applied. Biological assays were carried out in order to evaluate the nanocarrier nanotoxicity in vitro and in vivo, as well as to evaluate antiglioma activity. The nanosystems were able to successfully manifest functional properties under pH conditions, and their biocompatibility and cellular internalization were also evident. The chimeric nanoplatforms presented herein have shown promise for biomedical applications so far and should be further studied in terms of their ability to deliver TRAM-34 and other therapeutic molecules to glioblastoma cells.

Tyrosine-modified linear PEIs for highly efficacious and biocompatible siRNA delivery in vitro and in vivo

Therapeutic gene silencing by RNA interference relies on the safe and efficient in vivo delivery of small interfering RNAs (siRNAs). Polyethylenimines are among the most studied cationic polymers for gene delivery. For several reasons including superior tolerability, small linear PEIs would be preferable over branched PEIs, but they show poor siRNA complexation. Their chemical modification for siRNA formulation has not been extensively explored so far. We generated a set of small linear PEIs bearing tyrosine modifications (LPxY), leading to substantially enhanced siRNA delivery and knockdown efficacy in vitro in various cell lines, including hard-to-transfect cells. The tyrosine-modified linear 10 kDa PEI (LP10Y) is particularly powerful, associated with favorable physicochemical properties and very high biocompatibility. Systemically administered LP10Y/siRNA complexes reveal antitumor effects in mouse xenograft and patient-derived xenograft (PDX) models, and their direct application into the brain achieves therapeutic inhibition of orthotopic glioma xenografts. LP10Y is particularly interesting for therapeutic siRNA delivery.

Comparison of the effects of dendrimer, micelle and silver nanoparticles on phospholipase A2 structure

The interaction of nanoparticles (NP) with proteins (the so-called 'protein corona') is a huge challenge in attempting to apply them in personalized nanomedicine. We have analyzed the interaction between A) two 'soft' NPs (a cationic phosphorus dendrimer of generation 3; a cationic phosphorus amphiphilic dendron of generation 2), and B) one 'hard' nanoparticle (silver NP covered with cationic carbosilane dendritic moieties); and membrane-bound protein phospholipase A2 from bovine pancreas. The hard and soft NPs have differences in the nature of their interactions with phospholipase A2. This enzyme surrounds hard AgNP, whereas dendrimer and amphiphilic dendron form aggregates/micelles with phospholipase A2. There is a difference in action of phospholipase A2 bound to the core of dendrimer, and of micelles formed from non-covalent interactions between the amphiphilic dendron. These data are important in understanding the nature of interaction between different kinds of nanoparticles and proteins.

Dendronized Gold Nanoparticles as Carriers for gp160 (HIV-1) Peptides: Biophysical Insight into Complex Formation

The unavailability of effective and safe human immunodeficiency virus (HIV) vaccines incites several approaches for development of the efficient antigen/adjuvant vaccination composite. In this study, three different dendronized gold nanoparticles (AuNPs 13-15) were investigated for a complexation ability with gp160 synthetic peptides derived from an HIV envelope. It has been shown that HIV peptides interacted with nanoparticles as evident from the changes in their secondary structures, restricted the mobility of the attached fluorescence dye, and enhanced peptide helicity confirmed by the fluorescence polarization and circular dichroism results. Transmission electron microscopy visualized complexes as cloud-like structures with attached nanoparticles. AuNP 13-15 nanoparticles bind negatively charged peptides depending on the number of functional groups; the fastest saturation and peptide retardation were observed for the most dendronized nanoparticle as indicated from dynamic light scattering, laser Doppler velocimetry, and agarose gel electrophoresis experiments. Dendronized gold nanoparticles can be considered one of the potential HIV peptide-based vaccination platforms.

Combined therapy of ruthenium dendrimers and anti-cancer drugs against human leukemic cells

Carbosilane ruthenium(ii) dendrimers have been complexed with conventional anti-cancer drugs. Due to its features, the presence of ruthenium within a dendrimer structure improves the anti-cancer properties of nanocomplexes containing 5-flurouracyl, methotrexate and doxorubicin. These dendrimers could be promising carriers of anti-cancer medicines. Ruthenium dendrimers that are positively charged can also enhance the cytotoxicity to cancer cells; moreover, they can form stable complexes with drugs. Results indicate that ruthenium dendrimers combined with doxorubicin and methotrexate significantly reduced the viability of leukaemia 1301 and HL-60 cancer cells.

Economic rationale on the use of m-Health in uncontrolled hypertensive outpatients: from three months and beyond

Background/Introduction

Current scientific data show that blood pressure (BP) telemonitoring with/without additional counseling is rather effective in hypertension (HTN) management. However, cost-effectiveness and long-term social sequelae are lacking. This is because of diverse technologies and economic climate which make results highly heterogeneous across countries.

Purpose

To construct predictive model of long-term outcomes and to conduct the cost-effectiveness analysis of BP telemonitoring and remote counseling (BPTM) using m-Health in Russian population of outpatients with HTN.

Methods

Total of 240 patients were randomized (2:1) to either BPTM (n=160, mean age 47 y.o.) and to usual care (UC, n=80, mean age 49 y.o.) with baseline, three-month follow-up clinic visits combined with ambulatory BP measurement (ABPM). BPTM consisted of m-Health tool for patients, desktop module for clinicians. It enables BP data transfer and analysis, secure web chatting to support and counsel. Main outcomes were change in office, ambulatory systolic (S) BP and rate of BP control. A Markov cohort-based (1000 patients per study arm) model was developed and adopted a 10-year time horizon with 12-month time cycles. All patients started at a non-complicated HTN “well” state with a certain possibility of disease progression in a number of health states over a discrete time period. BPTM was compared with usual care in terms of 10-year healthcare costs, quality adjusted life years (QALY) using a Ministry of Health of Russian Federation perspective. Incremental cost-effectiveness ratio (ICER), incremental cost-utility ratio (ICUR) represented economic analysis.

Results

BPTM was associated with steeper decrease in office, ambulatory SBP (−16,8 mm Hg and −8,9 mm Hg, respectively; p<0,05) with the same treatment intensity (2,4 drugs per patient). There were 102 (64%) and 11 (14%) patients with fully controlled HTN in BPTM and UC groups, respectively (OR 11,03 95% CI [5,4–22,5]). An ICER of BPTM resulted in additional 11,1 EUR/1 mm Hg/year. It is expected that BPTM will be at least 76% cost-effective as per relevant Russian willingness-to-pay threshold. In a modelled 10-year period BPTM was life-saving (9,71 vs 9,6 life years gained) and cheap (cost of illness 1,5 mln vs 2,1 mln EUR). BPTM was also more valuable (8,31 versus 7,82 QALYs gained) so the ICUR was 3601,47 EUR/QALY gained. Cost-effectiveness was further confirmed by one-way deterministic sensitivity analysis.

Conclusion

BPTM seems to be clinically and economically effective when implemented into clinical practice. It provides greater BP reduction, improves BP control short-term. In a long-term it is likely to reduce cardiovascular morbidity and mortality in a cost-effective way. Larger randomized studies are needed to confirm these pilot results.

Cost-effectiveness acceptability curve

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): The Russian Scientific Foundation

Heterofunctional ruthenium(II) carbosilane dendrons, a new class of dendritic molecules to fight against prostate cancer

A family of heterofunctional Schiff base carbosilane metallodendrons with [Ru(η⁵-C₅H₅)(PTA)Cl] (PTA = 1,3,5-triaza-7-phosphatricyclo-[3.3.1.1]decane) at the focal point and dimethylamino groups on the periphery are described. The new systems have proved their ability to interact with biological molecules such as Human Serum Albumin (HSA) without affecting its secondary structure and erythrocytes membranes, causing haemolysis in a dose and generation dependent way. The combination of two active functional groups in one single dendritic platform has shown a cooperative effect in the viability of HeLa and PC-3 cells, with the second generation derivative standing out as the most promising with the lowest IC₅₀. Experiments focused on advanced prostate cancer have shown an antimetastasic activity for those metallodendrons, hindering the adhesion of cells in one of the main targets of metastasis, bones, and inhibiting cell migration. Finally, the second generation metallodendron with one single metal centre and four dimethylamino groups on the dendritic wedge, was selected for an ex vivo experiment in nude mice with advanced prostate cancer inhibiting the tumour growth in a 40% compared to control mice.

Ruthenium Dendrimers against Human Lymphoblastic Leukemia 1301 Cells

Ruthenium atoms located in the surfaces of carbosilane dendrimers markedly increase their anti-tumor properties. Carbosilane dendrimers have been widely studied as carriers of drugs and genes owing to such characteristic features as monodispersity, stability, and multivalence. The presence of ruthenium in the dendrimer structure enhances their successful use in anti-cancer therapy. In this paper, the activity of dendrimers of generation 1 and 2 against 1301 cells was evaluated using Transmission Electron Microscopy, comet assay and Real Time PCR techniques. Additionally, the level of reactive oxygen species (ROS) and changes of mitochondrial potential values were assessed. The results of the present study show that ruthenium dendrimers significantly decrease the viability of leukemia cells (1301) but show low toxicity to non-cancer cells (peripheral blood mononuclear cells-PBMCs). The in vitro test results indicate that the dendrimers injure the 1301 leukemia cells via the apoptosis pathway.

Cyclopentadienyl ruthenium(II) carbosilane metallodendrimers as a promising treatment against advanced prostate cancer

In searching for efficient and selective antitumour drugs, a new family of carbosilane metallodendrimers functionalized with [Ru(η⁵-C₅H₅)(PTA)Cl] (PTA = 1,3,5-triaza-7-phosphatricyclo-[3.3.1.1] decane) is reported. Experiments of the biophysical characterization showed an ability to interact with biological membranes, as well as with proteins (e.g. human serum albumin) without affecting their usual biological activity. These metallodendrimers possessed potent and selective anticancer activity in vitro in a panel of tumour cell lines. Importantly, the first generation metallodendrimer, bearing 4 Ru(II) complexes, was remarkably active towards resistant prostate cancer cells, inhibiting both cell proliferation and metastasis to bone tissues. Such promising antitumour activity can be further improved when given with docetaxel, with in vitro cytotoxicity being in the nanomolar range. Furthermore, its intravenous administration to an advanced prostate cancer mice model inhibited tumour growth up to 25% and 45% when given 10 mg/kg/week and 7.5 mg/kg/4-5 days, respectively.

Zeta potential technique for analyzing semen quality

The presented study shows the possibility of using the zeta potential technique in sperm selection. Results suggest that the characteristics of semen may be reflected in the sperm surface charge, which can be measured by a simple Zeta technique. This is a pilot study that answers question whether a commercially available Zeta Potential analyzer can be used to determine the quality of human semen. Semen samples were obtained from young adult men donors and divided into portions to analyze the motility, viability, morphology, concentration and zeta potential. Results indicate that zeta potential of semen samples with right structural and functional parameters was significantly more negative in comparison to the other samples. Our use of a Zeta potential analyzer to investigate sperm surface charge adds a new dimension to data on semen quality. It is an additional simple method that helps in the widely-used routine methods of semen analysis. •

Characteristics of semen may be reflected in the sperm surface charge, which can be measured by Zeta potential technique.

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Only 20 µl semen being needed to analyze spermatozoa surface charge.

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The commercially available Zeta Potential analyzer can be applied for semen quality investigation.

Physicochemical and in vitro cytotoxicity studies of inclusion complex between gemcitabine and cucurbit[7]uril host

Gemcitabine, a cytostatic drug from the pyrimidine antimetabolite group, exhibits limited storage stability and numerous side effects during therapy. One of the strategies to improve the effectiveness of therapy with such drugs is the use of supramolecular nano-containers, including dendrimers and macrocyclic compounds. The ability of gemcitabine to attach a proton in an aqueous environment necessitates the search for a carrier that is well-tolerated by an organism and capable of supramolecular binding of a ligand (drug) in a cationic form. In the current study a promising strategy was tested for using cucurbituril Q7 to bind gemcitabine cations for its efficient intracellular delivery on three selected cancer cell lines (MOLT4, THP-1 and U937). Based on physicochemical studies (equilibrium dialysis, UV and ¹H NMR titrations, DOSY ¹H NMR measurements, DSC calorimetry) and cytotoxicity tests on cells with a free and blocked hENT1 transporter, the conclusion was drawn about the binding and penetration of the cucurbituril-drug complex into cancer cells.

Comparison of cationic liposome and PAMAM dendrimer for delivery of anti-Plk1 siRNA in breast cancer treatment

Delivery of negatively charged, high molecular weight and unstable siRNA is difficult. The present study describes the development and comparison of cationic liposomes (CLs) and polyamidoamine (PAMAM) dendrimer generation 4 (PG4) nanocarriers of gene for cancer therapy. CLs and PG4 were complexed with anticancer siRNA (siPlk1) to form siPlk1-CLs lipoplex and siPlk1-PG4 dendriplex. siPlk1-CLs/PG4 complexes were characterized for average particle size, zeta potential, fluorescence and integrity of siPlk1 by agarose gel electrophoresis, ethidium bromide intercalation assay, circular dichroism, protection against RNase and stability in serum. The complexation of CLs/siPlk1 and PG4/siPlk1 were at a 100/1 and 2/1 charge ratio respectively. The CLs and PG4 were effective in protecting siPlk1 from RNase activity, also they enhanced the siPlk1 serum stability. Additionally, siPlk1-CLs and siPlk1-PG4 were evaluated by cell culture studies. In vitro anticancer activity study using MCF-7 cells showed that siPlk1-CLs and siPlk1-PG4 causes nearly similar cell death. Both siPlk1-CLs and siPlk1-PG4 resulted in enhanced cellular uptake of siPlk1 in MDA-MB-231 cells compared to naked siPlk1 solution. Cell cycle analysis suggested that increased cell population arrest in subG1 phase by siPlk1-CLs and siPlk1-PG4 compared to naked siPlk1 solution. These observations suggested that CLs and PG4 can be a potential carrier for siPlk1 delivery in breast cancer treatment.

Dendrimer mediated targeting of siRNA against polo-like kinase for the treatment of triple negative breast cancer

Irresponsiveness of triple negative breast cancer (TNBC) toward conventional therapies has drawn attention toward siRNA therapeutics. In gene delivery, dendrimers are gaining significant attention due to their characteristic features and polo-like kinase (PLK1) is reported as a potential target for TNBC. In this work, phosphorus and polyamidoamine dendrimer (generation 3 and 4 of each type) are explored to address delivery challenges of PLK1 siRNA (siPLK1). Dendriplexes were formed and complexation was found at 3:1 N/P ratio for all dendrimers by gel electrophoresis. Complexation was also supported by zeta potential, circular dichroism and intercalation assay. Dendriplexes were found to be stable in presence of ribonuclease and serum. Dendriplexes resulted in enhanced cell uptake of siPLK1 compared to siPLK1 solution in MDA-MB-231 and MCF-7 cells. Dendriplexes caused increased cell arrest in sub-G1 phase compared to solution. These observations suggested phosphorus and polyamidoamine dendrimers as potential carriers for siPLK1 delivery to treat TNBC.

Synthesis and Characterization of FITC Labelled Ruthenium Dendrimer as a Prospective Anticancer Drug

Metallodendrimers-dendrimers with included metals-are widely investigated as biocompatible equivalents to metal nanoparticles. Applications can be expected in the fields of catalysis, as chemical sensors in molecular recognition and as anticancer drugs. Metallodendrimers can also mimic certain biomolecules, for example, haemoprotein in the case of using a dendrimer with a porphyrin core. In previous papers, we showed the promising anticancer effects of carbosilane ruthenium dendrimers. The present paper is devoted to studying biocompatibility and the cytotoxic effect on normal and cancer cells of carbosilane ruthenium dendrimers labelled with fluorescent probe fluorescein isothiocyanate (FITC). The addition of fluorescent probe allowed tracking the metallodendrimer in both normal and cancer cells. It was found that carbosilane ruthenium dendrimer labelled with FITC in concentration up to 10 µmol/L was more cytotoxic for cancer cells than for normal cells. Thus, FITC labelled carbosilane ruthenium dendrimer is a good candidate for diagnostic imaging and studying anticancer effects of metallodendrimers in cancer therapy.

Complexes of Pro-Apoptotic siRNAs and Carbosilane Dendrimers: Formation and Effect on Cancer Cells

This paper examines the complexation of anti-cancer small interfering RNAs (siRNAs) by cationic carbosilane dendrimers, and the interaction of the formed complexes with HeLa and HL-60 cancer cells. Stepwise formation of the complexes accompanied by the evolution of their properties has been observed through the increase of the charge ratio (dendrimer/siRNA). The complexes decrease the viability of both “easy-to-transfect” cells (HeLa) and “hard-to transfect” ones (HL-60), indicating a high potential of the cationic carbosilane dendrimers for siRNA delivery into tumor cells.

Dendrimer as a new potential carrier for topical delivery of siRNA: A comparative study of dendriplex vs. lipoplex for delivery of TNF-α siRNA

Topical delivery of siRNA is challenging task due to complex barrier property of stratum corneum and cationic lipid based carriers have been widely explored for this purpose due to improved permeation through skin. For gene delivery application, dendrimers are considered as efficient carrier due to their cationic nature and well-defined surface groups. However, they are not well explored for topical delivery. This work compares the suitability of PAMAM dendrimer with DOTAP liposome for topical delivery of siRNA against TNF-α. The particle size, zeta potential and entrapment efficiency of dendriplex were 99.80 ± 1.80 nm, 13.40 ± 4.84 mV and 98.72 ± 2.02% whereas for lipoplex were 174.80 ± 0.80 nm, 29.96 ± 0.51 mV and 94.99 ± 5.01% respectively. Both the formulations were stable in serum and in the presence of RNAse. TNF-α is inflammatory cytokine, hence the in vivo efficacy of developed formulations was determined using psoriatic plaque model. Results suggested improved phenotypic and histopathological features and reduced levels of IL-6, TNF-α, IL-17 and IL-22 for dendriplex and lipoplex treated groups in comparison to Imiquimod treated group. These findings suggest that dendrimer can be a potential carrier for topical gene delivery.

Ruthenium dendrimers as carriers for anticancer siRNA

Dendrimers, which are considered as one of the most promising tools in the field of nanobiotechnology due to their structural organization, showed a great potential in gene therapy, drug delivery, medical imaging and as antimicrobial and antiviral agents. This article is devoted to study interactions between new carbosilane-based metallodendrimers containing ruthenium and anti-cancer small interfering RNA (siRNA). Formation of complexes between anti-cancer siRNAs and Ru-based carbosilane dendrimers was evaluated by transmission electron microscopy, circular dichroism and fluorescence. The zeta-potential and the size of dendriplexes were determined by dynamic light scattering. The internalization of dendriplexes were estimated using HL-60 cells. Results show that ruthenium dendrimers associated with anticancer siRNA have the ability to deliver siRNA as non-viral vectors into the cancer cells. Moreover, dendrimers can protect siRNA against nuclease degradation. Nevertheless, further research need to be performed to examine the therapeutic potential of ruthenium dendrimers as well as dendrimers complexed with siRNA and anticancer drugs towards cancer cells.

Interaction of α-synuclein with Rhus typhina tannin - Implication for Parkinson's disease

The etiology of Parkinson's disease (PD) relates to α-synuclein, a small protein with the ability to aggregate and form Lewy bodies. One of its prevention strategies is inhibition of α-synuclein oligomerization. We have investigated the interaction of α-synuclein and human serum albumin with 3,6-bis-О-di-О-galloyl-1,2,4-tri-О-galloyl-β-d-glucose (a tannin isolated from the plant Rhus typhina). Using fluorescence spectroscopy method we found that this tannin interacts strongly with α-synuclein forming complexes. Circular dichroism analysis showed a time-dependent inhibition of α-synuclein aggregation in the presence of the tannin. On the other hand, 3,6-bis-О-di-О-galloyl-1,2,4-tri-О-galloyl-β-d-glucose had a much stronger interaction with human serum albumin than α-synuclein. The calculated binding constant for tannin-protein interaction was considerably higher for albumin than α-synuclein. This tannin interacted with albumin through a "sphere of action" mechanism. The results lead to the conclusion that 3,6-bis-О-di-О-galloyl-1,2,4-tri-О-galloyl-β-d-glucose is a potent preventive compound against Parkinson's disease. However, this tannin interacts very strongly with human serum albumin, significantly reducing the bioavailability of this compound.

Dendrimer-protein interactions versus dendrimer-based nanomedicine

Dendrimers are hyperbranched polymers belonging to the huge class of nanomedical devices. Their wide application in biology and medicine requires understanding of the fundamental mechanisms of their interactions with biological systems. Summarizing, electrostatic force plays the predominant role in dendrimer-protein interactions, especially with charged dendrimers. Other kinds of interactions have been proven, such as H-bonding, van der Waals forces, and even hydrophobic interactions. These interactions depend on the characteristics of both participants: flexibility and surface charge of a dendrimer, rigidity of protein structure and the localization of charged amino acids at its surface. pH and ionic strength of solutions can significantly modulate interactions. Ligands and cofactors attached to a protein can also change dendrimer-protein interactions. Binding of dendrimers to a protein can change its secondary structure, conformation, intramolecular mobility and functional activity. However, this strongly depends on rigidity versus flexibility of a protein's structure. In addition, the potential applications of dendrimers to nanomedicine are reviwed related to dendrimer-protein interactions.

HIV-antigens charged on phosphorus dendrimers as tools for tolerogenic dendritic cells-based immunotherapy

AIMS

The objective was to study if cationic phosphorus dendrimers can be used as DC-based vaccine or adjuvant in anti-HIV-1 vaccine development when associated with HIV-1 derived peptides.

MATERIALS & METHODS

The HIV derived peptides uptake in DC and the phenotype of iDC and mDC were studied using Flow Cytometry analysis. Migration of mDC was evaluated by an in vitro chemotaxis assay. Allogenic T-cells proliferative response induced by DC was studied using Flow Cytometry assays. Cytokines production was analysed by Diaclon DIAplex Th1/Th2/Inflammation kit.

RESULTS

All phosphorus dendrimers showed the ability to deliver HIV-derived peptides in DC. The phosphorus dendrimers from second and third generations induced important changes in phenotype. Moreover, the treatment of mDC with the second generation dendrimer and derivated dendriplexes modified cellular migratory properties, altered their capacity to stimulate allogenic naïve T cells in vitro and impeded the production of pro-inflammatory cytokines.

CONCLUSIONS

The phosphorus dendrimers cannot be used as vaccines because they would not have the ability to induce an immune response. The cationic phosphorus dendrimers associated with HIV-derived peptides have the ability to deliver peptides as non-viral vectors. However, there are other potential therapeutic applications of these compounds, for instance as topical antiinflammatory agents, as compounds for allograft rejection or autoimmune diseases and as agents inducing specific tolerance with antigen-loaded DC against allergy reaction. Nevertheless, these applications need to be evaluated.

Interaction between dendrimers and regulatory proteins. Comparison of effects of carbosilane and carbosilane–viologen–phosphorus dendrimers

For nanoparticles to be used successfully in biomedical application, their interactions with biological fluids need to be investigated, in which they will react with proteins and other macromolecules.

Biomolecular Interactions of Tannin Isolated from Oenothera gigas with Liposomes

We have examined the interaction between hydrolysable tannin 1-O-galloyl-4,6-hexahydroxydiphenoyl-β-D-glucose (OGβDG) with neutral liposomes as a model of cell membranes composed of three lipids: lecithin, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) at different mass ratios. OGβDG in the concentration range 0.5-15 µg/ml (0.4-12 µM) strongly interacts with liposomal membranes by changing their structure, surface charge and fluidity. Used OGβDG molecules decrease and increase the rigidity of hydrophilic surface and hydrophobic parts of liposomes, respectively. At higher concentrations of tannin (>15 µM), liposomes are aggregated. Fourier Transform Infra-Red (FTIR) analysis showed that mainly -OH groups from OGβDG and also PO(2-) groups from phospholipids are responsible for the interaction. Obtained data indicate the importance of membrane lipid composition in interactions between tannins and cells.

Anticancer siRNA cocktails as a novel tool to treat cancer cells. Part (B). Efficiency of pharmacological action

This paper examines a perspective to use newly engineered nanomaterials as effective and safe carriers for gene therapy of cancer. Three different groups of cationic dendrimers (PAMAM, phosphorus, and carbosilane) were complexed with anticancer siRNA and the biophysical properties of the dendriplexes created were analyzed. The potential of the dendrimers as nanocarriers for anticancer Bcl-xl, Bcl-2, Mcl-1 siRNAs and additionally a scrambled sequence siRNA has been explored. Dendrimer/siRNA complexes were characterised by various methods including fluorescence, zeta potential, dynamic light scattering, circular dichroism, gel electrophoresis and transmission electron microscopy. In this part of study, the transfection of complexes in HeLa and HL-60 cells was analyzed using both single apoptotic siRNAs and a mixture (cocktail) of them. Cocktails were more effective than single siRNAs, allowing one to decrease siRNAs concentration in treating cells. The dendrimers were compared as siRNA carriers, the most effective being the phosphorus-based ones. However, they were also the most cytotoxic on their own, so that in this regard the application of all dendrimers in anticancer therapy will be discussed.