Low Molecular Weight Polyethylenimine Research Articles

Evaluation of lipopolymer as therapeutic siRNA delivery agents in non-malignant and malignant primary cells.

e15189 Background: Targeting leukemia-driving oncogenes via short interfering RNA (siRNA) offers an alternative approach to leukemia treatment that can overcome the limitations of current therapies. Low molecular weight polyethyleneimine grafted with lipids (lipopolymers) have emerged as promising carriers for siRNA delivery to leukemia cells. Lipopolymers harboring select lipids were recently shown to downregulate target oncogene leading to significant anti-leukemic activity in both in vitro and in vivo cell line-based leukemia models. The goal of this study was to evaluate these lipopolymers in (i) PBMCs obtained from healthy donors to determine the potential impact on non-malignant cells, and (ii) primary leukemia patient cells to assess therapeutic efficacy. Methods: Target gene levels were determined by RT-qPCR and the effect of treatment on progenitor cells was assessed by measuring changes in colony forming ability. Results: At day 1 post-treatment, no changes in FLT3 mRNA levels were observed in all 6 PBMC samples with the 2 candidate lipopolymers (LeuFectB and LeuFectC) tested. Among 11 PBMC samples evaluated at day 2, only one sample showed a significant reduction in oncogene transcript levels on treatment with LeuFectB. The impact of lipopolymer/siRNA complex treatment on progenitor cells in the PBMC population was then assessed. Of the 7 PBMC samples tested, significant reduction in colony numbers was observed in one sample with LeuFectB and two samples with LeuFectC. On an average, the lipopolymer/siRNA complexes were well tolerated by normal healthy cells as changes observed in oncogene expression and colony forming ability were not consistent across the whole pool. Primary acute lymphoblastic leukemia (ALL) patient cells treated with complexes targeting STAT5A showed marked reduction in STAT5A transcript levels in 4 out of 7 samples with both the lipopolymers tested. The subsequent impact of STAT5A downregulation on the clonogenicity of leukemia stem cells was observed in the significant decrease in colony numbers seen in 3 samples (out of 8) with LeuFects. Additionally, combined downregulation of STAT5A and BCR-ABL genes in BCR-ABL+ ALL patient samples led to a notable decrease in cell proliferation and viability. Moreover,2 out of 3 acute myeloid leukemia (AML) patient samples harboring the FLT3-ITD mutation showed significant retardation in their colony forming ability on treatment with FLT3-targeting siRNA complexes. Collectively, the ALL and AML primary samples demonstrated promising preliminary results, suggesting a therapeutic effect on the stem cell population which is critical for mitigating relapse or prolonging remission. Conclusions: These findings provide further proof-of-concept for clinical translation of lipopolymer mediated siRNA therapy of leukemia, showing relative safety and selectivity of these lipopolymer/siRNA complexes.

A Simple and Cost-Effective FeCl3-Catalyzed Functionalization of Cellulose Nanofibrils: Toward Adhesive Nanocomposite Materials for Medical Implants.

In the present work, we explored Lewis acid catalysis, via FeCl3, for the heterogeneous surface functionalization of cellulose nanofibrils (CNFs). This approach, characterized by its simplicity and efficiency, facilitates the amidation of nonactivated carboxylic acids in carboxymethylated cellulose nanofibrils (c-CNF). Following the optimization of reaction conditions, we successfully introduced amine-containing polymers, such as polyethylenimine and Jeffamine, onto nanofibers. This introduction significantly enhanced the physicochemical properties of the CNF-based materials, resulting in improved characteristics such as adhesiveness and thermal stability. Reaction mechanistic investigations suggested that endocyclic oxygen of cellulose finely stabilizes the transition state required for further functionalization. Notably, a nanocomposite, containing CNF and a branched low molecular weight polyethylenimine (CNF-PEI 800), was synthesized using the catalytic reaction. The composite CNF-PEI 800 was thoroughly characterized having in mind its potential application as coating biomaterial for medical implants. The resulting CNF-PEI 800 hydrogel exhibits adhesive properties, which complement the established antibacterial qualities of polyethylenimine. Furthermore, CNF-PEI 800 demonstrates its ability to support the proliferation and differentiation of primary human osteoblasts over a period of 7 days.

Spray-drying of PEI-/PPI-based nanoparticles for DNA or siRNA delivery

Spray-drying of nucleic acid-based drugs designed for gene therapy or gene knockdown is associated with many advantages including storage stability and handling as well as the possibility of pulmonary application. The encapsulation of nucleic acids in nanoparticles prior to spray-drying is one strategy for obtaining efficient formulations. This, however, strongly relies on the definition of optimal nanoparticles, excipients and spray-drying conditions. Among polymeric nanoparticles, polyethylenimine (PEI)-based complexes with or without chemical modifications have been described previously as very efficient for gene or oligonucleotide delivery. The tyrosine-modification of linear or branched low molecular weight PEIs, or of polypropylenimine (PPI) dendrimers, has led to high complex stability, improved cell uptake and transfection efficacy as well as high biocompatibility.In this study, we identify optimal spray-drying conditions for PEI-based nanoparticles containing large plasmid DNA or small siRNAs, and further explore the spray-drying of nanoparticles containing chemically modified polymers. Poly(vinyl alcohol) (PVA), but not trehalose or lactose, is particularly well-suited as excipient, retaining or even enhancing transfection efficacies compared to fresh complexes. A big mesh size is critically important as well, while the variation of the spray-drying temperature plays a minor role. Upon spray-drying, microparticles in a ∼ 3.3 – 8.5 µm size range (laser granulometry) are obtained, dependent on the polymers. Upon their release from the spray-dried material, the nanoparticles show increased sizes and markedly altered zeta potentials as compared to their fresh counterparts. This may contribute to their high efficacy that is seen also after prolonged storage of the spray-dried material.We conclude that these spray-dried systems offer a great potential for the preparation of nucleic acid drug storage forms with facile reconstitution, as well as for their direct pulmonary application as dry powder.

Surface decoration of low molecular weight polyethylenimine (LMW PEI) by phthalated dextrin for improved delivery of interleukin-12 plasmid.

In this investigation, low molecular weight polyethyleneimine (LMW PEI; 1.8 kDa branched PEI) was conjugated to phathalated dextrin. The aim of this chemical modification was to decorate PEI molecules with a hydrophilic layer to improve its biophysical properties while the phthalic moiety may improve the hydrophilic-hydrophobic balance of the final structure. The polymers were prepared at various conjugation degrees ranging from 6.5% to 16.5% and characterized in terms of biophysical characteristics as well as their gene transfer ability and cell-induced toxicity. The results showed that dextrin-phthalated-PEI (DPHPEI) polymer was able to form nanoparticles with the size range of around 118-170 nm, with the zeta potential of 6.2-9.5 mV. DPHPEI polymers could increase the level of desired protein expression in the cells by up to three folds compared with unmodified LMW PEI while the cell viability of the modified polymers was around 80%. The result of this study shows a promising approach to improve the transfection efficiency of LMW PEI while maintaining its low toxic effects.

Tuning the Potency of Farnesol-Modified Polyethylenimine with Polyanionic Trans-Booster to Enhance DNA Delivery.

Low molecular weight polyethylenimine (PEI) based lipopolymers become an attractive strategy to construct nonviral therapeutic carriers with promising transfection efficiency and minimal toxicity. Herein, this paper presents the design and synthesis of novel farnesol (Far) conjugated PEI, namely PEI1.2k-SA-Far7. The polymers had quick DNA complexation, effective DNA unpacking (dissociation), and cellular uptake abilities when complexed with plasmid DNA. However, they were unable to provide robust transfection in culture, indicating inability of Far grafting to improve the transfection efficacy significantly. To overcome this limitation, the commercially available polyanionic Trans-Booster additive, which is capable of displaying electrostatic interaction with PEI1.2k-SA-Far7, has been used to enhance the uptake of pDNA polyplexes and transgene expression. pDNA condensation was successfully achieved in the presence of the Trans-Booster with more stable polyplexes, and in vitro transfection efficacy of the polyplexes was improved to be comparable to that obtained with an established reference reagent. The PEI1.2k-SA-Far7/pDNA/Trans-Booster ternary complex exhibited good compatibility with cells and minimal hemolysis activity. This work demonstrates the exemplary potency of using additives in polyplexes and the potential of resultant ternary complexes for effective pDNA delivery.

Zinc(II)-Quinoline module and ROS cleavable crosslinker functionalized self-fluorescent siRNA vectors for selective gene silencing of cancer cells

A highly efficient siRNA vector (Zn-PQD) capable of selectively silencing genes in cancer cells was obtained by using ROS-cleavable DED to crosslink low molecular weight (LMW) polyethylene imine (PEI) modified by self-fluorescent metal coordinatied multifunctional module Zn-QS. Under the combined action of DED cross-linking and Zn-QS modification, Zn-PQD performs well in the siRNA delivery process in cancer cells, including siRNA condensation, cell uptake, endosome escape, and siRNA release. Zn-PQD exhibited higher transfection efficiency than commercial PEI25k and Lipo2k in multiple cancer cell lines including HepG2, HeLa, 4 T1, H520 and PANC-1, as well as cancer treatment-related stem cell rADSC. Ultimately, Zn-PQD can achieve extremely high and selective gene silencing effects in cancer cells (with a gene silencing rate of 98.3% in HepG2). This work is expected to provide an efficient and safe siRNA carrier for the future tumor siRNA therapy and its study of fluorescence mediated mechanism.

Alkylated Sulfonium Modification of Low Molecular Weight Polyethylenimine to Form Lipopolymers as Gene Vectors.

Hydrophobic modification of low molecular weight polyethylenimine (PEI) is an efficient method to form ideal gene-transfer carriers. Sulfonium-a combination of three different functional groups, was conjugated onto PEI 1.8k at a conjugation ratio of 1:0.1 to form a series of sulfonium PEI (SPs). These SPs were hydrophobically modified and characterized by Fourier transform infrared and HNMR. DNA-condensing abilities of SPs were tested with gel retardation experiment, and their cytotoxicity was evaluated via the MTT assay. The particle size and zeta potential of SP/DNA nanoparticles were measured and evaluated for cellular uptake and transfection ability on HepG2 cell line. The results showed that the sulfonium moiety was attached to PEI 1.8k with a high yield at a conjugation ratio of 1:0.1. SPs containing longer alkyl chains condensed DNA completely at an SP/DNA weight ratio of 2:1. The formed nanoparticle size was in the range of 168-265 nm, and the zeta potential was +16-45 mV. The IC50 values of SPs were 6.5-43.2 μg/mL. The cytotoxicity of SPs increased as the hydrophobic chain got longer. SP/DNA showed much stronger cellular uptakes than PEI 25k; however, pure SPs presented almost no gene transfection on cells. Heparin release experiment showed that SP's strong binding of DNA resulted in low release of DNA and thus hindered the gene transfection process. By mixing SP with PEI 1.8k, the mixture presented adjustable DNA binding and releasing. The mixture formed by 67% SP and 33% PEI 1.8k showed strong gene transfection. In conclusion, sulfonium is an effective linkage to carry hydrophobic groups to adjust cell compatibilities and gene transfection capabilities of PEI.

ROS-responsive polyprodrug micelles carrying suicide genes in combination with chemotherapy and gene therapy for prostate cancer treatment.

Prostate cancer is the most common malignant tumor in the male reproductive system, and its incidence increases with age. Chemotherapy is one of the main strategies for treating prostate cancer, but it often comes with unavoidable side effects. Nanocarriers can improve drug utilization and targeting, and cationic carriers can also carry nucleic acids for gene therapy. In this study, we prepared a cationic micelle constructed from a polyprodrug that can deliver both chemotherapeutic drugs and nucleic acids simultaneously. The typical chemotherapeutic drug hydroxycamptothecin (HCPT) was linked by reactive oxygen species (ROS)-responsive coupling agents and forms amphiphilic block polymers with low molecular weight polyethyleneimine (PEI). The resulting cationic micelles can be triggered by high levels of ROS in tumor cells and collapse to release HCPT and suicide genes to kill tumor cells. At the same time, it reduces the killing of normal cells. In prostate cancer cells, it has been confirmed that the co-delivery carriers combined with chemotherapy and a suicide gene prodrug system have shown an ideal therapeutic effect on prostate cancer.

Lactosylated lipid calcium phosphate-based nanoparticles: A promising approach for efficient DNA delivery to hepatocytes.

For safe and effective gene therapy, the ability to deliver the therapeutic nucleic acid to the target sites is crucial. In this study, lactosylated lipid phosphate calcium nanoparticles (lac-LCP) were developed for targeted delivery of pDNA to the hepatocyte cells. The lac-LCP formulation contained lactose-modified cholesterol (CHL), a ligand that binds to the asialoglycoprotein receptor (ASGR) expressed on hepatocytes, and polyethyleneimine (PEI) in the core. Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR) were used to monitor the chemical modification, and the physicochemical properties of NPs were studied using dynamic light scattering (DLS) and transmission electron microscopy (TEM). To evaluate transfection efficiency, cellular uptake and GFP expression were assessed using fluorescence microscopy and flow cytometry. The results revealed that lactose-targeted particles (lac-LCP) had a significant increase in cellular uptake by hepatocytes. The inclusion of a low molecular weight PEI (1.8 KDa) with a low PEI/pDNA ratio of 1 in the core of LCP, elicited high degrees of GFP protein expression (by 5 and 6-fold), which exhibited significantly higher efficiency than PEI 1.8 KDa and Lipofectamine. The successful functionalization and nuclear delivery of LCP NPs described here indicate its promise as an efficient delivery vector to hepatocyte nuclei.

Multi-functionalized MCNs effectively improve the interfacial compatibility of mixed matrix membranes and enhance CO2 separation performance

Traditional two-dimensional (2D) membrane fillers are prone to interfacial defects such as agglomeration and phase separation in the membrane, limiting the separation performance of membrane. In this paper, microporous carbon nanoplates (MCNs) with controllable microporous structures were functionalized with two different amine carriers of low molecular weight polyethyleneimine (PEI) and 3-aminopropyl triethoxysilane (APTES) to prepare multi-functionalized microporous carbon nanoplates (MfMCNs). It is worth noting that with the success of composite functionalization, the filling content of mixed matrix membranes is also high to a certain extent. To a certain extent, it has been demonstrated that interfacial compatibility between the polymer and the fillers has been improved. It was confirmed by characterization technology that the morphology of the fillers had not been changed, but the pore size of MfMCNs was declined to 0.53–0.55 nm because part of the amino carrier was immersed in the pore structure of MfMCNs. The gas permeability tests under dry gas and wet gas conditions show that the improvement of phase interface by MfMCNs is significant. Under the condition of a dry gas test, the CO2/N2 selectivity of MfMCNs/Pebax-1.0 wt% MMMs is 76.3, which is 27 % higher than that of MCNs/Pebax-1.0 wt% MMMs. Under the moisture condition, the permeability and selectivity of MfMCNs/Pebax-1.0 wt% MMMs CO2 are 287.72 Barrer and 79.1 separately. Compared with Pebax membrane, the permeability of CO2 (176.6 Barrer) was rose by 62.9 %, and the selectivity of CO2 (59.1) was rose by 33.84 %. Significantly, the best MMMs separation performance exceeds upper limit of Robeson. This provides a powerful strategy to strengthen the compatibility between inorganic materials and polymers and strengthen the performance of MMMs in CO2 gas capture.

Regenerable planting of multifunctional amine: Regeneration-enhanced antifouling/antiscaling properties and performance of thin film composite nanofiltration membrane

The problems of poly(piperazineamide)-based thin film composite (TFC) nanofiltration (NF) membrane are the fouling, scaling and poor separation performance of uncharged organics and heavy metal ions. Permanent surface modification lowers the fouling/scaling problems. However, these problems persist as the separation progresses. We address these issues by the on-demand regenerable planting of polyethyleneimine (PEI) into the polyamide (PA) layer of TFC NF membrane. The regenerable planting is based on the electrostatic interaction among the protonated amine groups of low molecular weight PEI and ionized carboxylic acid groups situated at the relatively inner sites (low dielectric constant) of the PA network. The incorporated PEI chains are stable at the pH range of 3–9. The PEI incorporated membrane exhibits significantly enhanced antifouling/antiscaling property, rejection of heavy metal ions (98–99%) and bisphenol A (BPA, 95%) without much negatively affecting the bivalent anion rejection (Na2SO4, 97.5%) and water permeance (11 L m−2 h−1 bar−1) as compared to the pristine and commercial membranes (55–82%, 50–76% and 98–99% rejections of heavy metal ions, BPA and Na2SO4). Advantageously, PEI chains are removable at pH ≤ 2 or pH ≥ 9.5 without affecting the main PA layer. The multiple removal and re-generation of the membrane have been achieved. The flux recovery of the membrane after antifouling/antiscaling tests significantly improved upon intentional removal and reincorporation of PEI. Inherent properties of the modified membrane channels couple with the on-demand regenerable ability show immense promises of the membrane in the separation applications.

Nanozyme controlled photothermal heat generation on nanoceria decorated MoS2 nanoflowers for enhanced cytotoxicity in cancer chemo-photothermal therapy

In recent years, the fabrication of nanomaterials with built-in ability to mimick biological enzymes (nanozymes) is gaining popularity for biomedical applications, especially for cancer photothermal therapy, based on non-toxic and photo-thermal heat generating 2D materials. The use of 2D inter-layered MoS2 nanoflowers (NFs) is especially interesting as it results in nanozymes that are photostable and biocompatible for normal cells under physiological conditions. In this work, we have synthesized MoS2 nanoflowers (NFs) decorated with CeO2 nanoparticles (NPs) using two linker molecules of cysteine and polyethylenimine connected through carbodiimide chemistry. The electron microscopy investigations revealed the formation of flower shaped MoS2 of 400 ± 100 nm in size decorated with spherical shaped CeO2 NPs of 15±5 nm in size. The fabricated nanozymes were investigated by UV–visible (UV–vis), FTIR spectroscopy, Raman spectroscopy and dynamic light scattering. The NFs decorated with long-chain PEI molecules demonstrated higher photo-thermal heat generation when compared to nanozymes decorated with low molecular weight PEI. Notably, the photo-thermal heat generation, biocompatibility, anti-cancer activity of nanozymes are significantly influenced by molecular weight of PEI, concentration of nanozymes, time duration of near-infrared (NIR) light exposure, power density of NIR light and folic acid (FA) conjugation. The nanozymes conjugated with FA on their surface exhibited excellent anti-cancer activity against human colon cancer cells under NIR light exposure at 808 nm and 0.5 W/cm2. Hence, the nanozymes demonstrated here have huge potential as nanophoto-thermal agents in cancer photothermal therapy.

Genome editing mRNA nanotherapies inhibit cervical cancer progression and regulate the immunosuppressive microenvironment for adoptive T-cell therapy

CRISPR/Cas9-based genome editing is promising for therapy of cervical cancer by precisely targeting human papillomavirus (HPV). To develop CRISPR/Cas9-based genome editing nanotherapies, a pH-responsive hybrid nonviral nanovector was constructed for co-delivering Cas9 mRNA and guide RNAs (gRNAs) targeting E6 or E7 oncogenes. The pH-responsive nanovector was fabricated using an acetalated cyclic oligosaccharide (ACD), in combination with low molecular weight polyethyleneimine. Thus obtained hybrid ACD nanoparticles (defined as ACD NP) showed efficient loading for both Cas9 mRNA and E6 or E7 gRNA, giving rise to two pH-responsive genome editing nanotherapies E6/ACD NP and E7/ACD NP, respectively. Cellularly, ACD NP exhibited high transfection but low cytotoxicity in HeLa cervical carcinoma cells. Also, efficient genome editing of target genes was achieved in HeLa cells, with minimal off-target effects. In mice bearing HeLa xenografts, treatment with E6/ACD NP or E7/ACD NP afforded effective editing of target oncogenes and considerable antitumor activities. More importantly, treatment with E6/ACD NP or E7/ACD NP notably promoted CD8+ T cell survival by reversing the immunosuppressive microenvironment, thereby leading to synergistic antitumor effects by combination therapy using the gene editing nanotherapies and adoptive T-cell transfer. Consequently, our pH-responsive genome editing nanotherapies deserve further development for the treatment of HPV-associated cervical cancer, and they can also serve as promising nanotherapies to improve efficacies of other immune therapies against different advanced cancers by regulating the immunosuppressive tumor microenvironment.

Transdermal Delivery of Photosensitizer-Catalase Conjugate by Fluorinated Polyethylenimine for Enhanced Topical Photodynamic Therapy of Bacterial Infections.

Pathogenic bacteria induce subcutaneous infections pose serious threats to global public health. Recently, photodynamic therapy (PDT) has been proposed as a non-invasive approach for anti-microbial treatment without the risk to induce drug resistance. However, due to the hypoxic environment of most anaerobiont-infected sites, the therapeutic efficacy of oxygen consuming PDT has been limited. Herein, a transdermal delivery system is reported to allow effective delivery of photosensitizers into infected skin for PDT treatment of skin infections by bacteria. Considering the overproduction of hydrogen peroxide (H2 O2 ) in the abscess area, catalase (CAT), an enzyme that triggers H2 O2 decomposition to generate O2 , is conjugated with chlorine e6 (Ce6) to form a photosensitizer conjugate (Ce6-CAT) as an enhanced PDT agent against Staphylococcus Aureus. After screening a series of fluorinated low molecular weight polyethylenimine (F-PEI) with different fluorination degrees, the optimized F-PEI formulation is identified with the best transdermal delivery ability system. Upon mixing, the formed Ce6-CAT@F-PEI nanocomplex shows effective transdermal penetration after being applied to the skin surface. With light exposure of the infected skin, highly effective in vivo anti-bacterial PDT therapeutic effect with Ce6-CAT@F-PEI is observed. This work proposes a transdermal PDT therapeutic nanomedicine particularly promising for the anti-bacterial treatment of skin infections.

A nano-targeted co-delivery system based on gene regulation and molecular blocking strategy for synergistic enhancement of platinum chemotherapy sensitivity in ovarian cancer

Ovarian cancer (OC) has a low five-year survival rate, mainly because of its drug resistance to chemotherapy. It is the key to reverse drug resistance to combine multiple sensitization pathways to play a synergistic role. A nano scaled targeted co-delivery system (P123-PEI-G12, PPG) modified by bifunctional peptide tLyP-1-NLS (G12) was fabricated by using Pluronic P123 conjugated with low molecular weight polyethyleneimine (PEI). This delivery system can co-delivery Olaparib (Ola) and p53 plasmids to synergistically enhance the sensitivity of OC to platinum-based chemotherapy. P53@P123-PEI-G2/Ola (Co-PPGs) can achieve efficient tumor accumulation and cellular internalization through G12-mediated targeting. Co-PPGs then break down in the tumor cells, releasing the drug. Co-PPGs significantly enhanced the sensitivity of cisplatin (DDP) in platinum-resistant ovarian cancer (PROC) and synergistically inhibited the proliferation of PROC in vitro and in vivo. The sensitizing and synergistic effects of Co-PPGs were related to the activation of p53, inhibition of poly-ADP-ribose polymerase (PARP) and p-glycoprotein (P-gp) expression. This work provides a promising strategy for the effective treatment of PROC.

Triton modified polyethyleneimine conjugates assembled with growth arrest-specific protein 6 for androgenetic alopecia transdermal gene therapy.

Androgenetic alopecia is an androgen-dependent skin disorder that commonly affects hair follicle growth and hair loss. Gene therapy that can promote the proliferation and survival of hair follicle cells can be a potential choice for its cure. While transdermal application of therapeutic functional nucleic acids across the stratum corneum is quite difficult. Here, we first develop a transdermal agent for functional nucleic acid delivery using Triton X-100-modified low molecular weight polyethyleneimine (PEI-Triton-N, N​=​6 or 8). In vitro cell experiments demonstrate that the PEI-Triton-N conjugates can stably encapsulate and efficiently deliver plasmid DNA to hard-to-transfect keratinocyte HaCaT cells. Further mouse model studies show that PEI-Triton-6 can encapsulate and deliver growth arrest-specific protein 6 (Gas6) plasmid through transdermal administration. The transfected Gas6 prolongs the anagen status, inhibits the apoptosis of hair follicle cells, and further promotes the proliferation and differentiation of hair follicle cells. The PEI-Triton-6/pDNAGas6 complexes can obviously alleviate hair loss in androgenetic alopecia mice and provides a promising strategy for gene therapy via transdermal administration.

Delivery of siRNA using hyaluronic acid-guided nanoparticles for downregulation of CXCR4.

In this study, effective transport of small interfering RNAs (siRNAs) via hyaluronic acid (HA) receptor was carried out with biodegradable HA and low-molecular weight polyethyleneimine (PEI)-based transport systems. Gold nanoparticles (AuNPs) capable of giving photothermal response, and their conjugates with PEI and HA, were also added to the structure. Thus, a combination of gene silencing, photothermal therapy and chemotherapy, has been accomplished. The synthesized transport systems ranged in size, between 25 and 690 nm. When the particles were applied at a concentration of 100 μg mL-1 (except AuPEI NPs) in vitro, cell viability was above 50%. Applying radiation after the conjugate/siRNA complex (especially those containing AuNP) treatment, increased the cytotoxic effect (decrease in cell viability of 37%, 54%, 13%, and 15% for AuNP, AuPEI NP, AuPEI-HA, and AuPEI-HA-DOX, respectively) on the MDA-MB-231 cell line. CXCR4 gene silencing via the synthesized complexes, especially AuPEI-HA-DOX/siRNA was more efficient in MDA-MB-231 cells (25-fold decrease in gene expression) than in CAPAN-1 cells. All these results demonstrated that the synthesized PEI-HA and AuPEI-HA-DOX conjugates can be used as siRNA carriers that are particularly effective, especially in the treatment of breast cancer.

Enhanced therapeutic efficacy of doxorubicin against multidrug-resistant breast cancer with reduced cardiotoxicity

Doxorubicin (DOX), a commonly used anti-cancer drug, is limited by its cardiotoxicity and multidrug resistance (MDR) of tumor cells. Epigallocatechin gallate (EGCG), a natural antioxidant component, can effectively reduce the cardiotoxicity of DOX. Meanwhile, EGCG can inhibit the expression of P-glycoprotein (P-gp) and reverse the MDR of tumor cells. In this study, DOX is connected with low molecular weight polyethyleneimine (PEI) via hydrazone bond to get the pH-sensitive PEI-DOX, which is then combined with EGCG to prevent the cardiotoxicity of DOX and reverse the MDR of cancer cells. In addition, folic acid (FA) modified polyethylene glycol (PEG) (PEG-FA) is added to get the targeted system PEI-DOX/EGCG/FA. The MDR reversal and targeting ability of PEI-DOX/EGCG/FA is performed by cytotoxicity and in vivo anti-tumor activity on multidrug resistant MCF-7 cells (MCF-7/ADR). Additionally, we investigate the anti-drug resistant mechanism by Western Blot. The ability of EGCG to reduce DOX cardiotoxicity is confirmed by cardiotoxicity assay. In conclusion, PEI-DOX/EGCG/FA can inhibit the expression of P-gp and reverse the MDR in tumor cells. It also shows the ability of remove oxygen free radicals effectively to prevent the cardiotoxicity of DOX.

Self‐Fluorescent Reactive Oxygen Species‐Responsive Zinc(II)‐Quinoline Module Functionalized Polycations Hold Great Potentials in siRNA‐Mediated Gene Therapy

AbstractA novel quinoline‐based thioketal‐containing zinc (II) coordinative module (Zn‐QS) is designed to transform common low‐molecular‐weight (LMW) polyethyleneimine (PEI) into a high‐performance siRNA carrier (Zn‐PQ) with self‐fluorescence and reactive oxygen species (ROS)‐responsiveness. In the multifunctional module, a quinoline derivative, frequently serving as pharmacophore, is utilized as the highly biocompatible ligand, and the Zn (II) coordinative quinoline‐based ligand also provides the robust self‐fluorescence character. And the ROS‐responsive thioketal spacer is introduced to trigger the siRNA controlled release into cytoplasm. Consequently, by the synergistic effects between Zn‐QS and LMW PEI on improving several crucial transfection‐efficiency‐related steps, the representative Zn‐PQ4 exhibits very high transfection efficiency of 1.8 and 2.5‐folds commercial Lipo2k and PEI25k in stem cell rADSC, respectively, >90% of transfection rates in a variety of conventional cell lines (3T3, HK‐2, HepG2, 293T, HeLa, PANC‐1), and 98.4% and 99.9% EGFP knockdown rates in 293T and HepG2 cells, respectively. Furthermore, Zn‐PQ4/siRNA polyplexes can circumvent various obstacles existing in systemic application to accumulate in heart, liver, and kidney and greatly silence the DNA expression in vivo. This work demonstrates the promising application prospects of the resulting efficient siRNA carriers in siRNA‐mediated gene therapy and fluorescence‐guided research.

Simultaneous identification of three clinically relevant peruvian pit vipers by multiplex loop-mediated isothermal amplification (mLAMP)

Previous knowledge about the taxonomic distribution of venomous snake species is very useful for epidemiological aspects of ophidism. Here, we sought to develop an assay for the differential identification of clinically relevant snakes in Peru: Bothrops atrox, Lachesis muta, and Crotalus durissus using a multiplex loop-mediated isothermal amplification (mLAMP) assay. For this, DNA was extracted from the shed snake skins and the mitochondrial genes Cytb, COI, and 12S rRNA were amplified and further sequenced, for the design of mLAMP reaction primers. For each snake species the forward and reverse primers, internal forward and reverse primers, and the loop primers were obtained, bearing the latter different fluorophores for product identification. Finally, the reaction was standardized in the presence of all primer sets, and an optimal amount of low molecular weight polyethyleneimine. The precipitated products were observed in a UV light transilluminator, finding a differential fluorescence according to the DNA used, with a detection limit to the naked eye in the range of 0.2–25 ng of DNA, within 30 min. This study is the first report on the use of mLAMP technology for the identification of venomous snakes.