Blood compatible N-maleyl chitosan-graft-PAMAM copolymer for enhanced gene transfection

Highly Efficient Photoswitchable Smart Polymeric Nanovehicle for Gene and Anticancer Drug Delivery in Triple-Negative Breast Cancer

Over the past few decades, there has been significant interest in smart drug delivery systems capable of carrying multiple drugs efficiently, particularly for treating genetic diseases such as cancer. Despite the development of various drug delivery systems, a safe and effective method for delivering both anticancer drugs and therapeutic genes for cancer therapy remains elusive. In this study, we describe the synthesis of a photoswitchable smart polymeric vehicle comprising a photoswitchable spiropyran moiety and an amino-acid-based cationic monomer-based block copolymer using reversible addition-fragmentation chain transfer (RAFT) polymerization. This system aims at diagnosing triple-negative breast cancer and subsequently delivering genes and anticancer agents. Triple-negative breast cancer patients have elevated concentrations of Cu2+ ions, making them excellent targets for diagnosis. The polymer can detect Cu2+ ions with a low limit of detection value of 9.06 nM. In vitro studies on doxorubicin drug release demonstrated sustained delivery at acidic pH level similar to the tumor environment. Furthermore, the polymer exhibited excellent blood compatibility even at the concentration as high as 500 μg/mL. Additionally, it displayed a high transfection efficiency of approximately 82 ± 5% in MDA-MB-231 triple-negative breast cancer cells at an N/P ratio of 50:1. It is observed that mitochondrial membrane depolarization and intracellular reactive oxygen species generation are responsible for apoptosis and the higher number of apoptotic cells, which occurred through the arrest of the G2/M phase of the cell cycle were observed. Therefore, the synthesized light-responsive cationic polymer may be an effective system for diagnosis, with an efficient anticancer drug and gene carrier for the treatment of triple-negative breast cancer in the future.

The Introduction of Dendrimers as a New Approach to Improve the Performance and Quality of Various Blood Products (Platelets, Plasma and Erythrocytes): A 2010-2022 Review Study

Objectives:

Platelet-, erythrocyte- and plasma-related products are vital for some patients. The main problems with these products are storage lesions, shelf life limitations, and function and quality maintenance. Dendrimers, a well-known group of polymeric nanoparticles, may help overcome these challenges due to their special properties.

Methods:

This review article, for the first time, comprehensively discusses studies from 2010 to 2022 on the compatibility of positive, negative, neutral, and modified charge dendrimers with each blood product. Moreover, it provides information regarding dendrimers' applications for improving the quality and function of blood products.

Results:

A total of one hundred and twenty-six studies showed that dendrimers affect blood components depending on their load, size, molecular weight, functional group, concentration, and exposure time. Generally, cationic dendrimers with higher concentrations and molecular weight and larger size showed little hemocompatibility, while anionic or neutral dendrimers with lower concentrations and molecular weight, and small size were more hemocompatible. Further, some modifications of cationic dendrimers were found to improve their compatibility. For erythrocytes, they included PEGylation and thiolation of dendrimers or functionalizing them with cyclic RGD, nmaleyl chitosan, zwitterionic chitosan, prednisolone, or carbohydrates. Additionally, dendrimers functionalized with arginine-birch, lysine-Cbz, polyethylene glycol, polyethylene glycol-cyclic RGD, thiol, TiO2, maltotriose, or streptokinase decreased the platelet toxicity of dendrimers. The dendrimers modified with polyethylene glycol, glucose, and gold nanoparticles showed increased compatibility in the case of albumin products. Moreover, the PAMAM-dendrimer-antibody conjugates had no adverse effect on antibodies. Dendrimers have a wide range of applications, including virus detection kits, synthetic O2 carriers, bacterial nanofilters, drug carriers, anticoagulants, and enhanced blood product storage.

Conclusion:

It can be concluded that due to the outstanding properties of different types of dendrimers, particularly their manipulability, nanomaterials can be promising to enhance the quality of blood products. Thus, further research in this area is required.

Evaluating the performance of bridging-assembly chelating flocculant for heavy metals removal: Role of branched architectures

A novel chelating flocculant with branched architectures, polyacrylamide grafted maleoyl chitosan-mercaptoacetic acid (PAM-g-M(CS-MA)), was successfully fabricated using maleic anhydride as the "bridge" between chitosan and polyacrylamide. The functional groups and structural characteristic information of copolymers were obtained via characterization analysis. Flocculation performance was systematically investigated via purifying a series of simulated wastewater containing Cu or Cd. The properties of the flocs were studied to give in-depth evidences for the role of chelation groups and branched architectures in flocculation. Results indicated that PAM-g-M(CS-MA) showed excellent flocculation capacity for heavy metals in high concentrations and was superior to other chelating flocculants. The maximum flocculation efficiency of Cu (93.90%) and Cd (92.47%) was achieved by PAM-g-M(CS-MA) at pH 7, dosage of 100 mg L^-1 and stirring speed of 90 rpm. The flocculation mechanisms of PAM-g-M(CS-MA) were deeply explored through the analyses of floc properties. The strong synergistic chelation of mercapto, carboxyl, amide and hydroxyl groups predominated for the capturing of heavy metals; and the branched architectures facilitated the formation of large and stable flocs via adsorption and bridging-furl effect. This study provided a solid foundation for the fabrication of flocculants for heavy metal wastewater treatment.

Hemocompatibility and Hemolytic Effects of Functionalized Nanoparticles on Red Blood Cells: A Recent Review Study

In this paper (from 2010 to 2020), the effects of polymeric, metallic and nonmetallic nanoparticles on red blood cells’ hemocompatibility were investigated for the first time. Here, we have considered the latest findings which can help to improve the hemocompatibility of RBCs. It is important to maintain the quality of red blood cells for improving the hemocompatibility because blood products directly affect the health of patients after blood transfusion. Although RBCs can be stored for up to 42 days at 2–6∘C, hypothermic storage lesions (HSLs) are very common in these products. This problem affects the quality of RBC products. Thus, it is necessary to modify the surface molecules of RBCs during storage time to reduce HSLs and alloimmunization complications. Therefore, we reviewed the reported effects of polymeric, metallic and carbon-based nanoparticles on RBCs between 2010 and 2020. The results of our study have shown that the use of negatively charged dendrimers, unsaturated/uncharged liposomes, and PEGylated forms of NPs and RBCs are the best approaches to improve the hemocompatibility conditions of red blood cells. However, large cationic dendrimers, liposomes composed of saturated lipid with long acyl chain, and cationic chitosan nanoparticles have less RBC compatibility. In addition, polymeric nanoparticles have more capacity for surface modification, which makes it possible to make more hemocompatible derivatives. Among metallic nanoparticles, gold and iron nanoparticles were more RBC compatible. However, the smaller size, higher concentration and longer exposure time of these nanoparticles can induce hemolysis and morphological changes in RBCs. On the other side, nonmetallic nanoparticles mostly had poor RBC compatibility, but their effects on RBCs strongly depended on their concentration and physicochemical properties and could be controllable. As a result, the use of polyethylene glycol (PEG), gold, polymeric, and iron nanoparticles in the design of protocols to maintain the survival, structure and activity of red blood cells for improving hemocompatibility can be more effective.

Low molecular weight polyethyleneimine conjugated guar gum for targeted gene delivery to triple negative breast cancer

The study emphasized on the development of an efficient, receptor-targeted non-viral gene delivery vehicle for gene therapy of triple negative breast cancer (TNBC). Here, naturally abundant guar gum based non-viral carrier was developed through conjugating by low molecular weight polyethylenimine (LPEI) (GNP) using napthalic anhydride coupling agent and characterized them by FT-IR, ¹H NMR, XRD and UV spectrophotometer. The carrier was found to be cytocompatible as revealed by MTT assay against MDA-MB-231 and HeLa cell lines and excellent blood compatibility till the concentration of 200 μg/ml. In addition to these, the carrier exhibited excellent gene binding capability and formed spherical shaped complexes. The carrier showed very high in vitro transfection efficiency in TNBC cell (MDA-MB-231) compared to lipofectamine 2000 (LF2k) which could be justified by its high buffering capacity. Therefore, GNP may be an attractive non-viral gene carrier for gene therapy of TNBC in future.

Supramolecular Assembly of Amino Acid Based Cationic Polymer for Efficient Gene Transfection Efficiency in Triple Negative Breast Cancer

The success of gene therapy is enormously dependent on an efficient gene carrier, and in this context, cationic polymers still continue to play a major role particularly with respect to the safety issue compared to viral vectors. Developing an efficient gene carrier system having promising gene transfection efficiency with low toxicity is the foremost impediment associated with a nonviral carrier. Here, we explored amino acid based biocompatible polymers synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization where glycine (Gly), leucine (Leu), and phenyl alanine (Phe) amino acids were used as the pendent groups of the polymeric brushes. The presence of both a hydrophobic group (long chain aliphatic group associated with the RAFT agent) and hydrophilic amino groups was associated with the supramolecular assembly of the polymeric chain having hydrodynamic sizes within the range of 150-300 nm with a positive zeta potential of 30 ± 5 mV. All polymers showed very low toxicity and possessed >80% cell viability even at a very high concentration of 1000 μg/mL against both normal and cancerous cells. In addition to this, the polymers also showed excellent blood compatibility, and negligible hemolysis was observed at the concentration of 500 μg/mL. All polymers showed efficient DNA complexation capability as well as excellent protection of DNA against highly negatively charged surfactant and enzymatic digestion, although the efficiency was dependent on the N/P ratio of polymer/DNA complexes. Interestingly, the phenyl alanine moiety containing polymer brush P(HEMA-Phe-NH₂) showed a hexagonal shaped nanoparticle after complexation with pDNA and consequently showed higher cellular uptake, resulting in a higher transfection efficiency in a triple negative breast cancer cell, the MDA-MB-231 cell. Therefore, the synthesized polymer containing an amino acid pendent group, especially the phenyl alanine moiety, may be a promising nonviral gene carrier system in gene therapy application in the future.

Ultrasound-enhanced gene delivery to alfalfa cells by hPAMAM dendrimer nanoparticles

Cationic polyamidoamine (PAMAM) dendrimers are highly branched nanoparticles with unique molecular properties, which make them promising nanocarriers for gene delivery into cells. This research evaluated the ability of hyperbranched PAMAM (hPAMAM)-G2 with a diethylenetriamine core to interact with DNA, its protection from ultrasonic damage, and delivery to alfalfa cells. Additionally, the effects of ultrasound on the efficacy of hPAMAM-G2 for the delivery and expression of the gus A gene in the alfalfa cells were investigated. The electrophoresis retardation of plasmid DNA occurred at an N/P ratio (where N is the number of hPAMAM nitrogen atoms and P is the number of DNA phosphorus atoms) of 3 and above, and hPAMAM-G2 dendrimers completely immobilized the DNA at an N/P ratio of 4. The analysis of the DNA dissociated from the dendriplexes revealed a partial protection of the DNA from ultrasound damage at N/P ratios lower than 2, and with increasing N/P ratios, the DNA was better protected. Sonication of the alfalfa cells in the presence of ssDNA-FITC-hPAMAM increased the ssDNA delivery efficiency to 36%, which was significantly higher than that of ssDNA-FITC-hPAMAM without sonication. Additionally, the efficiency of transfection and the expression of the gus A gene were dependent on the N/P ratio and the highest efficiency (1.4%) was achieved at an N/P ratio of 10. The combination of 120 s of ultrasound and hPAMAM-DNA increased the gusA gene transfection and expression to 3.86%.

Biofunctionalized surface-modified silver nanoparticles for gene delivery

Silver nanoparticles (AgNPs) find use in different biomedical applications including wound healing and cancer. We propose that the efficacy of the nanoparticles can be further augmented by using these particles for gene delivery applications. The objective of this work was to engineer biofunctionalized stable AgNPs with good DNA binding ability for efficient transfection and minimal toxicity. Herein, we report on the one-pot facile green synthesis of polyethylene glycol (PEG) stabilized chitosan-g-polyacrylamide modified AgNPs. The size of the PEG stabilized AgNPs was 38 ± 4 nm with a tighter size distribution compared to the unstabilized nanoparticles which showed bimodal distribution of particle sizes of 68 ± 5 nm and 7 ± 4 nm. To enhance the efficiency of gene transfection, the Arg-Gly-Asp-Ser (RGDS) peptide was immobilized on the silver nanoparticles. The transfection efficiency of AgNPs increased significantly after immobilization of the RGDS peptide reaching up to 42 ± 4% and 30 ± 3% in HeLa and A549 cells, respectively, and significantly higher than 34 ± 3% and 23 ± 2%, respectively, with the use of polyethyleneimine (25 kDa). These nanoparticles were found to induce minimal cellular toxicity. Differences in cellular uptake mechanisms with RGDS immobilization resulting in improved efficiency are elucidated. This study presents biofunctionalized AgNPs for potential use as efficient nonviral carriers for gene delivery with minimal cytotoxicity toward augmenting the therapeutic efficacy of AgNPs used in different biomedical products.

A study on the hemocompatibility of dendronized chitosan derivatives in red blood cells

Dendrimers are hyperbranched macromolecules with well-defined topological structures and multivalent functionalization sites, but they may cause cytotoxicity due to the presence of cationic charge. Recently, we have introduced alkyne-terminated poly(amidoamine) (PAMAM) dendrons of different generations (G=2,3) into chitosan to obtain dendronized chitosan derivatives [Cs-g-PAMAM (G=2,3)], which exhibited a better water solubility and enhanced plasmid DNA transfection efficiency. In this study, we attempted to examine the impact of Cs-g-PAMAM (G=2,3) at different concentrations (25 μg/mL, 50 μg/mL, and 100 μg/mL) on the morphology, surface structure, and viability of rat red blood cells (RBCs). The results showed that treatment of RBCs with Cs-g-PAMAM (G=2,3) at 50 μg/mL and 100 μg/mL induced a slightly higher hemolysis than Cs, and Cs-g-PAMAM (G=3) caused a slightly higher hemolysis than Cs-g-PAMAM (G=2), but all values were <5.0%. Optical microscopic and atomic force microscopic examinations indicated that Cs-g-PAMAM (G=2,3) caused slight RBC aggregation and lysis. Treatment of RBCs with 100 μg/mL Cs-g-PAMAM (G=3) induced echinocytic transformation, and RBCs displayed characteristic irregular contour due to the folding of the periphery. Drephanocyte-like RBCs were observed when treated with 100 μg/mL Cs-g-PAMAM (G=3). Erythrocytes underwent similar shape transition upon treatment with Cs-g-PAMAM (G=2) or Cs. The roughness values (Rms) of RBCs incubated with Cs-g-PAMAM (G=2,3) were significantly larger than those for RBCs incubated with physiological saline (P<0.01), but the Rms showed no difference for Cs and Cs-g-PAMAM (G=2,3) (P>0.05). Furthermore, Cs-g-PAMAM (G=2,3) exhibited a lower cytotoxicity in human kidney 293T cells. These results indicate that Cs-g-PAMAM (G=2,3) are hemocompatible but may disturb membrane and lipid structures at higher concentrations. Further safety and biocompatibility evaluations are warranted for Cs-g-PAMAM. Our findings prove helpful for a better understanding of the advantages of combining PAMAM dendrimers and chitosan to design and develop new, safe, and effective drug delivery vehicles.

Assessment of in vivo chronic toxicity of chitosan and its derivates used as oral insulin carriers

In the present study, the chronic oral toxicity of chitosan derivates was investigated in the mice model.

Dendron conjugation to graphene oxide using click chemistry for efficient gene delivery

Owing to its large surface area and rapid cellular uptake, graphene oxide (GO) is emerging as an attractive candidate material for delivery of drugs and genes.

A self-assembling polycationic nanocarrier that exhibits exceptional gene transfection efficiency

A novel polycationic gene carrier was prepared by conjugation of low molecular weight polyethyleneimine with gelatin through 4-bromonaphthaleic anhydride with exceptionally high transfection efficiency.

Biocompatibility of a self-assembled glycol chitosan nanogel

The research of chitosan-based nanogel for biomedical applications has grown exponentially in the last years; however, its biocompatibility is still insufficiently reported. Hence, the present work provides a thorough study of the biocompatibility of a glycol chitosan (GC) nanogel. The obtained results showed that GC nanogel induced slight decrease on metabolic activity of RAW, 3T3 and HMEC cell cultures, although no effect on cell membrane integrity was verified. The nanogel does not promote cell death by apoptosis and/or necrosis, exception made for the HMEC cell line challenged with the higher GC nanogel concentration. Cell cycle arrest on G1 phase was observed only in the case of RAW cells. Remarkably, the nanogel is poorly internalized by bone marrow derived macrophages and does not trigger the activation of the complement system. GC nanogel blood compatibility was confirmed through haemolysis and whole blood clotting time assays. Overall, the results demonstrated the safety of the use of the GC nanogel as drug delivery system.