Gold nanoparticles capped with polyethyleneimine for enhanced siRNA delivery

MCT Nanoemulsions for the Efficient Delivery of siRNA

In this study, an oil-in-water (o/w) nanoemulsion is used to deliver siRNA targeting Twist1, a protein that contributes to tumor metastasis in a variety of cancers. The FDA-approved oil, medium chain triglycerides (MCT), is used as the hydrophobic phase for the nanoemulsion. The siRNA is paired with dioleoyl-3-trimethylammonium-propane (DOTAP) to form a hydrophobic salt that is soluble at high concentrations in MCT. The resulting MCT/siRNA-DOTAP solution is formulated into a nanoemulsion with an average particle size of 140 nm. The nanoemulsion displays long term stability over the course of 195 days. In an in vivo murine tumor model, the nanoemulsion facilitates a 46% decrease in Twist1 mRNA after 48 h.

The landscape of nanoparticle-based siRNA delivery and therapeutic development

Five small interfering RNA (siRNA)-based therapeutics have been approved by the Food and Drug Administration (FDA), namely patisiran, givosiran, lumasiran, inclisiran, and vutrisiran. Besides, siRNA delivery to the target site without toxicity is a big challenge for researchers, and naked-siRNA delivery possesses several challenges, including membrane impermeability, enzymatic degradation, mononuclear phagocyte system (MPS) entrapment, fast renal excretion, endosomal escape, and off-target effects. The siRNA therapeutics can silence any disease-specific gene, but their intracellular and extracellular barriers limit their clinical applications. For this purpose, several modifications have been employed to siRNA for better transfection efficiency. Still, there is a quest for better delivery systems for siRNA delivery to the target site. In recent years, nanoparticles have shown promising results in siRNA delivery with minimum toxicity and off-target effects. Patisiran is a lipid nanoparticle (LNP)-based siRNA formulation for treating hereditary transthyretin-mediated amyloidosis that ultimately warrants the use of nanoparticles from different classes, especially lipid-based nanoparticles. These nanoparticles may belong to different categories, including lipid-based, polymer-based, and inorganic nanoparticles. This review briefly discusses the lipid, polymer, and inorganic nanoparticles and their sub-types for siRNA delivery. Finally, several clinical trials related to siRNA therapeutics are addressed, followed by the future prospects and conclusions.

Nano-scale delivery systems for siRNA delivery in cancer therapy: New era of gene therapy empowered by nanotechnology

RNA interference (RNAi) is a unique treatment approach used to decrease a disease's excessive gene expression, including cancer. SiRNAs may find and destroy homologous mRNA sequences within the cell thanks to RNAi processes. However, difficulties such poor cellular uptake, off-target effects, and susceptibility to destruction by serum nucleases in the bloodstream restrict the therapeutic potential of siRNAs. Since some years ago, siRNA-based therapies have been in the process of being translated into the clinic. Therefore, the primary emphasis of this work is on sophisticated nanocarriers that aid in the transport of siRNA payloads, their administration in combination with anticancer medications, and their use in the treatment of cancer. The research looks into molecular manifestations, difficulties with siRNA transport, the design and development of siRNA-based delivery methods, and the benefits and drawbacks of various nanocarriers. The trapping of siRNA in endosomes is a challenge for the majority of delivery methods, which affects the therapeutic effectiveness. Numerous techniques for siRNA release, including as pH-responsive release, membrane fusion, the proton sponge effect, and photochemical disruption, have been studied to overcome this problem. The present state of siRNA treatments in clinical trials is also looked at in order to give a thorough and systematic evaluation of siRNA-based medicines for efficient cancer therapy.

Study on the flocculation mechanism of a bioflocculant from Acinetobacter sp. TH40 combined with graphene oxide for the removal of metal ions from water

In order to realize the simultaneous removal of nine metal ions from water, in this study, an excellent flocculant suitable for the simultaneous removal of multiple metal ions in water was developed by using the excellent flocculation properties of graphene oxide (GO) combined with biological flocculants. First, this study investigated the concentrations and pollution levels of nine metal pollutants in surface water and groundwater of a typical city in central China. The maximum concentrations of these nine metal ions were Al 0.29, Ni 0.0325, Ba 0.948, Fe 1.12, As 0.05, Cd 0.01, Zn 1.45, Mn 1.24, and Hg 0.16 (in mg/L). Second, the three-dimensional structure diagram of GO was established. Gaussian16W software and the pm6D3 semi-empirical method were used to analysis the structure and the vibration of GO. The B3LYP function and basis set DEF2SVP was used to calculate the single point energy. Third, with varying the flocculation time, it was found that the maximum flocculation efficiency could reach more than 80.00% under the optimal conditions, that is, with a metal ion mixture of 20 mg/L. The optimal dosage of GO was 15 mg/L. The optimal time for bioflocculation efficiency was 2.5 h, and the optimal concentration of bioflocculant was 3 mg/L. The optimal flocculation efficiency was 82.01% under the optimal conditions.

Gold nanoparticles (AuNPs) can rapidly deliver artificial microRNA (AmiRNA)-ATG6 to silence ATG6 expression in Arabidopsis

KEY MESSAGE

We establish a fast and efficient transient silencing system that facilitates functional studies of some genes, whose knockout leads to plant lethality. In plants, the generation of loss-of-function mutants is crucial for studying gene function. Artificial microRNA (AmiRNA) technology is a more targeted and effective tool for gene silencing. Gold nanoparticles (AuNPs) can bind nucleic acids and deliver them into animal cells. Here, AuNPs are used in combination with AmiRNA technology in plants. We found that AmiRNA-autophagy-related proteins (ATG6) can be delivered to cells by AuNPs to achieve the effect of ATG6 silencing. It is worth noting that on the 10th day there is still a silencing effect. Similar to the atg5 lines, silencing of ATG6 significantly reduced plant resistance to Pseudomonas syringae pv.maculicola (Psm) ES4326/AvrRpt2. Interestingly, ATG6 silencing and ATG5 mutation in NPR1-GFP (nonexpressor of pathogenesis-related genes) lines significantly reduced plant resistance to Psm ES4326/AvrRpt2, suggesting that autophagy is also involved in NPR1-regulated plant immune responses. In summary, we establish a fast and efficient transient silencing system that facilitates functional studies of some genes, whose knockout leads to plant lethality.

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.

Research progress on non-protein-targeted drugs for cancer therapy

Non-protein target drugs, especially RNA-based gene therapies for treating hereditary diseases, have been recognized worldwide. As cancer is an insurmountable challenge, no miracle drug is currently available. With the advancements in the field of biopharmaceuticals, research on cancer therapy has gradually focused on non-protein target-targeted drugs, especially RNA therapeutics, including oligonucleotide drugs and mRNA vaccines. This review mainly summarizes the clinical research progress in RNA therapeutics and highlights that appropriate target selection and optimized delivery vehicles are key factors in increasing the effectiveness of cancer treatment in vivo.

Polyethyleneimine/polyethylene glycol-conjugated gold nanoparticles as nanoscale positive/negative controls in nanotoxicology: testing in frog embryo teratogenesis assay-Xenopus and mammalian tissue culture system

Despite the great potential of using positively charged gold nanoparticles (AuNPs) in nanomedicine, no systematic studies have been reported on their synthesis optimization or colloidal stability under physiological conditions until a group at the National Institute of Standards and Technology recently succeeded in producing remarkably stable polyethyleneimine (PEI)-coated AuNPs (Au-PEI). This improved version of Au-PEI (Au-PEI25kB) has increased the demand for toxicity and teratogenicity information for applications in nanomedicine and nanotoxicology. In vitro assays for Au-PEI25kB in various cell lines showed substantial active cytotoxicity. For advanced toxicity research, the frog embryo teratogenesis assay-Xenopus (FETAX) method was employed in this study. We observed that positively-charged Au-PEI25kB exhibited significant toxicity and teratogenicity, whereas polyethylene glycol conjugated AuNPs (Au-PEG) used as comparable negative controls did not. There is a characteristic avidity of Au-PEI25kB for the jelly coat, the chorionic envelope (also known as vitelline membrane) and the cytoplasmic membrane, as well as a barrier effect of the chorionic envelope observed with Au-PEG. To circumvent these characteristics, an injection-mediated FETAX approach was utilized. Like treatment with the FETAX method, the injection of Au-PEI25kB severely impaired embryo development. Notably, the survival/concentration curve that was steep when the standard FETAX approach was employed became gradual in the injection-mediated FETAX. These results suggest that Au-PEI25kB may be a good candidate as a nanoscale positive control material for nanoparticle analysis in toxicology and teratology.

Multilayer gold nanoparticles as non-viral vectors for targeting MCF-7 cancer cells

Cargocomplexes play a vital role in non-viral delivery methods due to their capacity to target certain cells (or cells through the cell-division cycle) and inject their (macro)molecular "cargo" into them. The development of gene carriers that can efficiently transport and deliver genetic material into human-targeted cells with minimal toxicity is an important challenge in the field. The present study reports the straightforward preparation and testing of a modular non-viral gene carrier based on AuNPs. The design, synthesis, and in vitro evaluation of multilayer gold nanoparticles (AuNPs) as non-viral gene carriers with high transfection efficiency, reduced cytotoxicity for targeted therapeutic delivery of nucleic acids to MCF-7 cancer cells are presented. The developed non-viral vector is based on supramolecular "host-guest" inclusion complexes of β-cyclodextrin, positioned on the AuNPs surface over a layer of polyethyleneimine, and adamantyl moiety from polyethylene glycol conjugated decapeptide (WXEAAYQRFL). First, the β-CD functionalized PEI was utilized as the template for the synthesis of AuNPs of controlled sizes. The reaction produced small AuNPs with a cationic layer which is known for efficient condensation of genetic material and β-CD suitable for the decoration of the carrier with targeting moieties using "host-guest" inclusion complexation. Subsequently, adamantine-polyethylene glycol conjugated decapeptide was attached to the AuNPs. The in vitro results have validated the ability of the proposed systems to selectively target tumor cells with high efficacy and low toxicity due to the unique affinity of the aptamer-functionalized nanoparticles toward breast cancer cells. The findings of this work demonstrated that the proposed modular system may represent a very promising platform for the AuNP-based non-viral vectors mainly due to the versatility of the system, which allows for the facile exchange of several types of ligands for improving the targeting properties and transfection efficiency, or for providing better protection from the endocytotic systems.

Cationic Polyethyleneimine (PEI)–Gold Nanocomposites Modulate Macrophage Activation and Reprogram Mouse Breast Triple-Negative MET-1 Tumor Immunological Microenvironment

Nanomedicines based on inorganic nanoparticles have grown in the last decades due to the nanosystems’ versatility in the coating, tuneability, and physical and chemical properties. Nonetheless, concerns have been raised regarding the immunotropic profile of nanoparticles and how metallic nanoparticles affect the immune system. Cationic polymer nanoparticles are widely used for cell transfection and proved to exert an adjuvant immunomodulatory effect that improves the efficiency of conventional vaccines against infection or cancer. Likewise, gold nanoparticles (AuNPs) also exhibit diverse effects on immune response depending on size or coatings. Photothermal or photodynamic therapy, radiosensitization, and drug or gene delivery systems take advantage of the unique properties of AuNPs to deeply modify the tumoral ecosystem. However, the collective effects that AuNPs combined with cationic polymers might exert on their own in the tumor immunological microenvironment remain elusive. The purpose of this study was to analyze the triple-negative breast tumor immunological microenvironment upon intratumoral injection of polyethyleneimine (PEI)–AuNP nanocomposites (named AuPEI) and elucidate how it might affect future immunotherapeutic approaches based on this nanosystem. AuPEI nanocomposites were synthesized through a one-pot synthesis method with PEI as both a reducing and capping agent, resulting in fractal assemblies of about 10 nm AuNPs. AuPEI induced an inflammatory profile in vitro in the mouse macrophage-like cells RAW264.7 as determined by the secretion of TNF-α and CCL5 while the immunosuppressor IL-10 was not increased. However, in vivo in the mouse breast MET-1 tumor model, AuPEI nanocomposites shifted the immunological tumor microenvironment toward an M2 phenotype with an immunosuppressive profile as determined by the infiltration of PD-1-positive lymphocytes. This dichotomy in AuPEI nanocomposites in vitro and in vivo might be attributed to the highly complex tumor microenvironment and highlights the importance of testing the immunogenicity of nanomaterials in vitro and more importantly in vivo in relevant immunocompetent mouse tumor models to better elucidate any adverse or unexpected effect.

Turning Hot into Cold: Immune Microenvironment Reshaping for Atherosclerosis Attenuation Based on pH-Responsive shSiglec-1 Delivery System

Current atherosclerosis treatment is based on a combination of cholesterol-lowering medication and low-fat diets; however, the clinical effect is unsatisfactory. It has been shown that the level of immune cell infiltration and pro-inflammatory factors in the atherosclerotic immune microenvironment (AIM) play important roles in the development and progression of atherosclerosis. Therefore, we hypothesized that reshaping "hot AIM" into "cold AIM" could attenuate atherosclerosis. For this purpose, we designed a pH-responsive and charge-reversible nanosystem, referred to as Au-PEI/shSiglec-1/PEI-acetylsalicylic acid (ASPA NPs) to effectively deliver shSiglec-1, which blocked the interactions between macrophages with CD8⁺ T/NKT cells, thus inhibiting immune cell infiltration. Further, we demonstrated that acetylsalicylic acid (ASA), detached from the pH-responsive PEI-ASA polymer, and inhibited lipid accumulation in macrophage, thereby decreasing the lipid antigen presentation. Additionally, reduced macrophage-produced inflammatory factors by ASA and low CD8⁺ T/NKT cell infiltration levels synergistically inhibit Th17 cell differentiation, thus further dramatically attenuating inflammation in AIM by decreasing the IL-17A production. Eventually, ASPA NPs efficiently reshaped AIM by inhibiting immune cell infiltration, lipid antigen presentation, and pro-inflammation, which provided a feasible therapeutic strategy for atherosclerosis immunotherapy.

Active targeting of CD4+T lymphocytes by PEI-capped, peptide-functionalized gold nanoparticles

Active targeting is a promising approach for the treatment of viral infections. In particular, site-specific formulations for the treatment of HIV infection may overcome challenges associated with current ARV regimens. In this study we explored active targeting by synthesizing a gold nanoparticle construct decorated with an anti-CD4 cyclic peptide. The aim was to demonstrate selectivity of the system for the CD4 receptor and to deliver the RNA payload into T-lymphocytes. Colloidal gold nanoparticles functionalized withN-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) were formed by a one-pot synthesis method where thiol modified polyethyleneimine (PEI) was mixed with chloroauric acid. PEI-SPDP AuNPs (gold nanoparticles) were conjugated to an anti-CD4 peptide and loaded with RNA. We measured toxicity and uptake using TZM-bl and HeLa cells. Our findings show that the nanoparticles bind selectively to CD4 + cells. UV-vis characterisation of the nanoparticles revealed a surface plasmon resonance (SPR) peak at 527 nm, corresponding to a 6 nm diameter. HRTEM of the complete nanoparticles visualised circular shaped particles with average diameter of ∼7 nm. The polydispersity index was calculated to be 0.08, indicating monodispersity of complete NPS in solution. Through the pyridine-2-thione assay each nanoparticle was calculated to carry 1.37 × 10⁵SPDP molecules available for peptide binding. Flow cytometry showed that 13.6% of TZM-bl cells, and 0.14% of HeLa cells retained fluorescence after an overnight incubation, an indication of system binding. No internal RNA delivery was demonstrated. Further work is required to improve internalization.

MicroRNA-activated hydrogel scaffold generated by 3D printing accelerates bone regeneration

Bone defects remain a major threat to human health and bone tissue regeneration has become a prominent clinical demand worldwide. The combination of microRNA (miRNA) therapy with 3D printed scaffolds has always posed a challenge. It can mimic physiological bone healing processes, in which a biodegradable scaffold is gradually replaced by neo-tissue, and the sustained release of miRNA plays a vital role in creating an optimal osteogenic microenvironment, thus achieving promising bone repair outcomes. However, the balance between two key factors - scaffold degradation behavior and miRNA release profile - on osteogenesis and bone formation is still poorly understood. Herein, we construct a series of miRNA-activated hydrogel scaffolds (MAHSs) generated by 3D printing with different crosslinking degree to screened the interplay between scaffold degradation and miRNA release in the osteoinduction activity both in vitro and in vivo. Although MAHSs with a lower crosslinking degree (MAHS-0 and MAHS-0.25) released a higher amount of miR-29b in a sustained release profile, they degraded too fast to provide prolonged support for cell and tissue ingrowth. On the contrary, although the slow degradation of MAHSs with a higher crosslinking degree (MAHS-1 and MAHS-2.5) led to insufficient release of miR-29b, their adaptable degradation rate endowed them with more efficient osteoinductive behavior over the long term. MAHS-1 gave the most well-matched degradation rate and miR-29b release characteristics and was identified as the preferred MAHSs for accelerated bone regeneration. This study suggests that the bio-adaptable balance between scaffold degradation behavior and bioactive factors release profile plays a critical role in bone regeneration. These findings will provide a valuable reference about designing miRNAs as well as other bioactive molecules activated scaffold for tissue regeneration.

Harnessing self-assembling peptide nanofibers toprime robust tumor-specific CD8 T cell responses in mice

Induction of tumor-specific CD8 + T cell responses is known as a major challenge for cancer vaccine development; here we presented a strategy to improve peptide nanofibers-mounted antitumor immune responses. To this end, peptide nanofibers bearing class I (Kb)-restricted epitope (Epi-Nano) were formulated with polyethylene imine backbone (Epi-Nano-PEI), and characterized using morphological and physicochemicalcharacterizationtechniques. Nanofibers were studied in terms of their uptake by antigen-presenting cells (APCs), antigen cross-presentation capacity, and cytotoxic activity. Furthermore, nanofibers were assessed by their potency to induce NLRP3 inflammasome-related cytokines and factors. Finally, the ability of nanofibers to induce tumor-specific CD8 T cells and tumor protection were investigated in tumor-bearing mice. The formulation of Epi-Nano with PEI led to the formation of short strand nanofibers with a positive surface charge, a low critical aggregation concentration (CAC), and an increased resistancetoproteolytic degradation. Epi-Nano-PEI was significantly taken up more efficiently by antigen-presenting cells (APCs), and was more potent in cross-presentation when compared to Epi-Nano. Moreover, Epi-Nano-PEI, in comparison to Epi-Nano, efficiently up-regulated the expression of NLRP3, caspase-1, IL-1b, IL18 and IL-6. Cell viability analysis showed that formulation of PEI with Epi-Nano not only abolished its cytotoxic activity, but surprisingly induced macrophage proliferation. Furthermore, it demonstrated that Epi-Nano-PEI triggered robust antigen-specific CD8+ T cell responses, and induced maximum antitumor response (tumor growth inhibition and prolonged survival) in tumor-bearing mice that were significantly higher compared to Epi-Nano. Taken together, the formulation of Epi-Nano with PEI is suggested as a promising strategy to improve nanofibers-mounted antitumor immune response.

Polymer-Conjugated Carbon Nanotubes for Biomolecule Loading

Nanomaterials have emerged as an invaluable tool for the delivery of biomolecules such as DNA and RNA, with various applications in genetic engineering and post-transcriptional genetic manipulation. Alongside this development, there has been an increasing use of polymer-based techniques, such as polyethylenimine (PEI), to electrostatically load polynucleotide cargoes onto nanomaterial carriers. However, there remains a need to assess nanomaterial properties, conjugation conditions, and biocompatibility of these nanomaterial-polymer constructs, particularly for use in plant systems. In this work, we develop mechanisms to optimize DNA loading on single-walled carbon nanotubes (SWNTs) with a library of polymer-SWNT constructs and assess DNA loading ability, polydispersity, and both chemical and colloidal stability. Counterintuitively, we demonstrate that polymer hydrolysis from nanomaterial surfaces can occur depending on polymer properties and attachment chemistries, and we describe mitigation strategies against construct degradation. Given the growing interest in delivery applications in plant systems, we also assess the stress response of plants to polymer-based nanomaterials and provide recommendations for future design of nanomaterial-based polynucleotide delivery strategies.

Polymer-Conjugated Carbon Nanotubes for Biomolecule Loading

Nanomaterials have emerged as an invaluable tool for the delivery of biomolecules such as DNA and RNA, with various applications in genetic engineering and post-transcriptional genetic manipulation. Alongside this development, there has been an increasing use of polymer-based techniques, such as polyethylenimine (PEI), to electrostatically load polynucleotide cargoes onto nanomaterial carriers. However, there remains a need to assess nanomaterial properties, conjugation conditions, and biocompatibility of these nanomaterial-polymer constructs, particularly for use in plant systems. In this work, we develop mechanisms to optimize DNA loading on single-walled carbon nanotubes (SWNTs) with a library of polymer-SWNT constructs and assess DNA loading ability, polydispersity, and both chemical and colloidal stability. Counterintuitively, we demonstrate that polymer hydrolysis from nanomaterial surfaces can occur depending on polymer properties and attachment chemistries, and we describe mitigation strategies against construct degradation. Given the growing interest in delivery applications in plant systems, we also assess the stress response of plants to polymer-based nanomaterials and provide recommendations for future design of nanomaterial-based polynucleotide delivery strategies.

Aptamer-Enabled Nanomaterials for Therapeutics, Drug Targeting and Imaging

A wide variety of nanomaterials have emerged in recent years with advantageous properties for a plethora of therapeutic and diagnostic applications. Such applications include drug delivery, imaging, anti-cancer therapy and radiotherapy. There is a critical need for further components which can facilitate therapeutic targeting, augment their physicochemical properties, or broaden their theranostic applications. Aptamers are single-stranded nucleic acids which have been selected or evolved to bind specifically to molecules, surfaces, or cells. Aptamers can also act as direct biologic therapeutics, or in imaging and diagnostics. There is a rich field of discovery at the interdisciplinary interface between nanomaterials and aptamer science that has significant potential across biomedicine. Herein, we review recent progress in aptamer-enabled materials and discuss pending challenges for their future biomedical application.

Response of Biological Gold Nanoparticles to Different pH Values: Is It Possible to Prepare Both Negatively and Positively Charged Nanoparticles?

The mycelium-free supernatant (MFS) of a five-day-old culture medium of Fusarium oxysporum was used to synthesize gold nanoparticles (AuNPs). The experimental design of the study was to answer the question: can this production process of AuNPs be controllable like classical chemical or physical approaches? The process of producing AuNPs from 1 mM tetrachloroauric (III) acid trihydrate in MFS was monitored visually by color change at different pH values and quantified spectroscopically. The produced AuNPs were analyzed by transmission electron microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The presence of capping agents was confirmed by Fourier transform infrared spectroscopy (FTIR). Two AuNP samples with acidic and alkaline pH were selected and adjusted with the pH gradient and analyzed. Finally, the size and zeta potential of all samples were determined. The results confirmed the presence of the proteins as capping agents on the surface of the AuNPs and confirmed the production of AuNPs at all pH values. All AuNP samples exhibited negative zeta potential, and this potential was higher at natural to alkaline pH values. The size distribution analysis showed that the size of AuNPs produced at alkaline pH was smaller than that at acidic pH. Since all samples had negative charge, we suspect that there were other molecules besides proteins that acted as capping agents on the surface of the AuNPs. We conclude that although the biological method of nanoparticle production is safe, green, and inexpensive, the ability to manipulate the nanoparticles to obtain both positive and negative charges is limited, curtailing their application in the medical field.

Cetuximab-siRNA Conjugate Linked Through Cationized Gelatin Knocks Down KRAS G12C Mutation in NSCLC Sensitizing the Cells Toward Gefitinib

Delivery of small-interfering RNA (siRNA) has been of great interest in the past decade for effective gene silencing. To overcome synthetic and regulatory challenges posed by nanoparticle-mediated siRNA delivery, antibody–siRNA conjugate (ARC) platform is emerging as a potential siRNA delivery system suitable for clinical translation. Herein, we have developed a delivery technology based on the ARC platform for stable delivery of siRNA called as Gelatin-Antibody Delivery System (GADS). In GADS, positively charged gelatin acts as a linker between antibody–siRNA and enables the endosomal escape of siRNA for gene silencing postcellular internalization. For proof of concept, we synthesized a scalable GADS conjugate comprising of Cetuximab (CTB), cationized gelatin (cGel) and NSCLC KRAS_G12C-specific siRNA. CTB was chemically conjugated to cGel through an amide link to form the CTB–cGel complex. Thereafter, siRNA was chemically conjugated to the cGel moiety of the complex through the thioether link to form CTB–cGel–siRNA conjugate. RP-HPLC analysis was used to monitor the reaction while gel retardation assay was used to determine siRNA loading capacity. SPR analysis showed the preservation of ligand binding affinity of antibody conjugates with K_D of ∼0.3 nM. Furthermore, cellular internalization study using florescent microscopy revealed receptor-mediated endocytosis. The conjugate targeted EGFR receptor of KRAS mutant NSCLC to specifically knockdown G12C mutation. The oncogene knockdown sensitized the cells toward small molecule inhibitor—Gefitinib causing ∼70% loss in cell viability. Western blot analysis revealed significant downregulation for various RAS downstream proteins postoncogene knockdown. Comparison of the efficiency of GADS vis-à-vis positive siRNA control and CRISPR–Cas9-based knockout of KRAS Exon 2 in the NCI-H23 NSCLC cell line suggests GADS as a potential technology for clinical translation of gene therapy.

The effects of surface functionality and size of gold nanoparticles on neuronal toxicity, apoptosis, ROS production and cellular/suborgan biodistribution

Gold nanoparticles are emerging as promising nanomaterials to create nanoscale therapeutic delivery systems. The aim of the study was to synthesis of highly monodisperse and stable gold nanoparticles functionalized with polyethyleneimine (PEI) and polyethylene glycol (PEG), multiparametric investigation of their neuronal toxicological effects and evaluation of the cellular/suborgan biodistribution. Gold nanoparticles (AuNP₂₀ and AuNP₅₀) were synthesized and their surfaces were electrostatically modified by PEI and PEG. Dorsal root ganglion (DRG) sensory neurones were isolated from BALB/c mice. Cell viability, apoptosis and ROS production were evaluated in vitro. Cellular and suborgan biodisribution of the AuNPs were investigated using inductively coupled plasma mass spectrometry (ICP-MS) technique. PEI and PEG surface coating increased both biocompatibility and biodistribution of the AuNPs. ICP-MS measurements showed the presence of gold in liver, spleen, kidney, heart, blood and brain within a 30 days period. The size and surface chemistry of the AuNPs are important parameters for potential nanoteranostic applications in the future studies.

Gold Nanoparticles Modified With Polyethyleneimine Disturbed the Activity of Drug-Metabolic Enzymes and Induced Inflammation-Mediated Liver Injury in Mice

Gold nanoparticles (GNPs) have been used as a potential bioactive platform for drug delivery due to their unique optical and thermal characteristics. Liver is the main organ in orchestrating physiological homeostasis through metabolization of drugs and detoxification of exogenous substances. Therefore, it is crucial to deeply understand the mechanism of nanoparticle–liver interaction and the potential hepatic effects of GNPs in vivo. In this study, we studied the hepatic impacts of the intravenously injected polyethyleneimine (PEI)-modified GNPs (PEI-GNPs) on the expression of hepatic drug-metabolic enzymes and sterol responsive element binding protein 1c (SREBP-1c)-mediated de novo lipogenesis in mice for 24 h and 1 week. PEI-GNP accumulation in the liver is associated with increased liver inflammation, as evidenced by the gene expression of pro-inflammatory cytokines. Moreover, the GNP-induced hepatotoxicity in mice is partly due to liver inflammation–triggered disruption in the function of drug-metabolic enzymes, including hepatic uptake and efflux transporters, cytochrome P450 (CYP450), and UDP-glucuronosyltransferases (UGTs). The study provides evidence that it is necessary to consider the nanomaterial–liver interaction and manipulate the surface chemistry of GNPs prior to biomedical application of nanoparticles.

The Nanosystems Involved in Treating Lung Cancer

Even though there are various types of cancer, this pathology as a whole is considered the principal cause of death worldwide. Lung cancer is known as a heterogeneous condition, and it is apparent that genome modification presents a significant role in the occurrence of this disorder. There are conventional procedures that can be utilized against diverse cancer types, such as chemotherapy or radiotherapy, but they are hampered by the numerous side effects. Owing to the many adverse events observed in these therapies, it is imperative to continuously develop new and improved strategies for managing individuals with cancer. Nanomedicine plays an important role in establishing new methods for detecting chromosomal rearrangements and mutations for targeted chemotherapeutics or the local delivery of drugs via different types of nano-particle carriers to the lungs or other organs or areas of interest. Because of the complex signaling pathways involved in developing different types of cancer, the need to discover new methods for prevention and detection is crucial in producing gene delivery materials that exhibit the desired roles. Scientists have confirmed that nanotechnology-based procedures are more effective than conventional chemotherapy or radiotherapy, with minor side effects. Several nanoparticles, nanomaterials, and nanosystems have been studied, including liposomes, dendrimers, polymers, micelles, inorganic nanoparticles, such as gold nanoparticles or carbon nanotubes, and even siRNA delivery systems. The cytotoxicity of such nanosystems is a debatable concern, and nanotechnology-based delivery systems must be improved to increase the bioavailability, biocompatibility, and safety profiles, since these nanosystems boast a remarkable potential in many biomedical applications, including anti-tumor activity or gene therapy. In this review, the nanosystems involved in treating lung cancer and its associated challenges are discussed.

Clinical Advances of siRNA-Based Nanotherapeutics for Cancer Treatment

Cancer is associated with single or multiple gene defects. Recently, much research has focused on incorporating genetic materials as one of the means to treat various types of carcinomas. RNA interference (RNAi) conveys an alternative genetic approach for cancer patients, especially when conventional medications fail. RNAi involves the inhibition of expression of specific messenger RNA that signals for uncontrollable cell growth and proliferation, most notably with carcinoma cells. This molecular technology is promising as genetic materials allow us to overcome issues associated with chemotherapeutic agents including organ damage associated with severe drug toxicities. Nonetheless, vast challenges impede successful gene therapy application, including low tumor localization, low stability and rapid clearance from the blood circulation. Owing to the limited treatment opportunities for the management of cancer, the development of effective siRNA carrier systems involving nanotherapeutics has been extensively explored. Over the past years, several siRNA nanotherapeutics have undergone a period of clinical investigation, with some demonstrating promising antitumor activities and safety profiles. Extensive observation of siRNA-nanoparticles is necessary to ensure commercial success. Therefore, this review mainly focuses on the progress of siRNAs-loaded nanoparticles that have undergone clinical trials for cancer treatment. The status of the siRNA nanotherapeutics is discussed, allowing comprehensive understanding of their gene-mediated therapeutics.

Multifunctional hierarchical nanohybrids perform triple antitumor theranostics in a cascaded manner for effective tumor treatment

Gene therapy based on transfection of RNAs/DNAs offers tremendous promise for tumor treatment. However, the relatively weak therapeutic efficiency of current genetic nanohybrids in vivo has limited the application of this strategy. Herein, we fabricated multifunctional core-shell-corona nanohybrids by combining cascaded theranostics for enhanced gene therapy. The nanohybrids consist of polydopamine-modified Fe₃O₄ nanoparticles as core, anti-miRNA-21 oligonucleotides (anti-miRNA) strands as shell, and doxorubicin (DOX)-conjugated DNA-8pb (DOX-DNA-8bp) as corona. The polydopamine/Fe₃O₄ core not only serves as an active agent for local photothermal therapy under NIR irradiation, but it also provides magnetic targeting to tumor tissue for accurate treatment, which could enhance the therapeutic effect and reduce the undesired side effects to healthy tissues. The DOX-DNA-8bp corona was grafted on the anti-miRNA shell through base pairing, which could be replaced by overexpressed miRNA-21 in tumor cells due to the strong interaction between miRNA-21 and anti-miRNA, resulting in tumor-specific gene therapy through tumorigenic miRNA-21 consumption and tumor selective chemotherapy through miRNA-21-triggered DOX-DNA-8bp release in tumor cells. Moreover, the intelligent controlled release system can gradually stop the release of DOX to prevent side effects caused by drug overdose, once sufficient damage of tumor cells has occurred, due to the downregulation of miRNA-21. The results of both in vitro and in vivo analyses showed that the nanohybrids combining cascaded chemo-photo-gene therapy could effectively inhibit tumor growth, promote the survival of tumor-bearing mice, and show no visible adverse effects on these mice, resulting in a promising nanoplatform for tumor treatment. STATEMENT OF SIGNIFICANCE: Gene therapy based on transfection of RNAs/DNAs offers tremendous promise for cancer treatment. However, the relatively weak therapeutic efficiency of current genetic nanovectors in vivo that results in insufficient tumor targeting and easy decomposition/elimination of RNAs/DNAs during therapy has limited its application. Although some approaches have combined photothermal agents or antitumor drugs with RNA/DNA nanocarriers to achieve better treatment, the spatiotemporal differences in photothermal therapy, chemotherapy, and gene therapy using current nanohybrids may hinder their synergistic effect. In the present study, we fabricated multifunctional core-shell-corona nanohybrids (Fe₃O₄@PDA@anti-miRNA/DNA) to simultaneously perform on-demand photothermal therapy, miR-21-triggered chemotherapy, and miR-21-dependent gene therapy at the same location, which can achieve an efficient synergistic effect for precise and effective tumor treatment.

Promising PEGylated cationic dendrimers for delivery of miRNAs as a possible therapy against HIV-1 infection

BACKGROUND

The appearance of resistance against new treatments and the fact that HIV-1 can infect various cell types and develop reservoirs and sanctuaries makes it necessary to develop new therapeutic approaches to overcome those failures.

RESULTS

Studies of cytotoxicity, genotoxicity, complexes formation, stability, resistance, release and particle size distribution confirmed that G2-SN15-PEG, G3-SN31-PEG, G2-SN15-PEG-FITC and G3-SN31-PEG-FITC dendrimers can form complexes with miRNAs being biocompatible, stable and conferring protection to these nucleic acids. Confocal microscopy and flow cytometry showed effective delivery of these four dendrimers into the target cells, confirming their applicability as delivery systems. Dendriplexes formed with the dendrimers and miRNAs significantly inhibited HIV-1 infection in PBMCs.

CONCLUSIONS

These dendrimers are efficient delivery systems for miRNAs and they specifically and significantly improved the anti-R5-HIV-1 activity of these RNA molecules.

Amine-terminated dendritic polymers as promising nanoplatform for diagnostic and therapeutic agents' modification: A review

It is often challenging to design diagnostic and therapeutic agents that fulfill all functional requirements. So, bulk and surface modifications as a common approach for biomedical applications have been suggested. There have been considerable research interests in using nanomaterials to the prementioned methods. Among all nanomaterials, dendritic materials with three-dimensional structures, host-guest properties, and nano-polymeric dimensions have received considerable attention. Amine-terminated dendritic structures including, polyamidoamine (PAMAM), polypropyleneimine (PPI), and polyethyleneimine (PEI), have been enormously utilized in bio-modification. This review briefly described the structure of these three common dendritic polymers and their use to modify diagnostic and therapeutic agents in six major applications, including drug delivery, gene delivery, biosensor, bioimaging, tissue engineering, and antimicrobial activity. The current review covers amine-terminated dendritic polymers toxicity challenging and improvement strategies as well.

Delivery of antisense oligonucleotides using multi-layer coated gold nanoparticles to methicillin-resistant S. aureus for combinatorial treatment

The spread of multidrug-resistant (MDR) bacterial infections has become a serious global threat. We introduce multi-layer coated gold nanoparticles (MLGNPs) delivering antisense oligonucleotides (ASOs) targeting the resistance gene of methicillin-resistant Staphylococcus aureus (MRSA), as a selective antimicrobial by restoring susceptibility. MLGNPs were prepared by multi-step surface immobilization of gold nanoparticles (GNPs) with polyethylenimine (PEI) and loaded with ASO targeting the mecA gene. The MLGNPs were shown to be efficiently internalized into various types of Gram-positive bacteria, including MRSA, Staphylococcus epidermidis, and Bacillus subtilis, which was superior to single-layer coated GNPs and free PEI polymer. The delivery of MLGNPs into MRSA resulted in up to 74% silencing of the mecA gene with high selectivity, in a dose-dependent manner. The treatment of MLGNPs to MRSA in the presence of oxacillin, a beta-lactam antibiotic, showed major suppression (~71%) of bacterial growth, due to the recovery of antibacterial sensitivity. Furthermore, the treatment of MLGNPs in a complex system showed preferential uptake into bacteria over mammalian cells, demonstrating the suitable characteristics of MLGNPs for selective delivery into bacteria. The current approach can be potentially applied for targeting various types of MDR bacterial infections by specific silencing of a resistance gene, as a combinatorial therapeutic used with conventional antibiotics.

Nanocarrier-delivered small interfering RNA for chemoresistant ovarian cancer therapy

Ovarian cancer is the fifth leading cause of cancer-related death in women in the United States. Because success in early screening is limited, and most patients with advanced disease develop resistance to multiple treatment modalities, the overall prognosis of ovarian cancer is poor. Despite the revolutionary role of surgery and chemotherapy in curing ovarian cancer, recurrence remains a major challenge in treatment. Thus, improving our understanding of the pathogenesis of ovarian cancer is essential for developing more effective treatments. In this review, we analyze the underlying molecular mechanisms leading to chemotherapy resistance. We discuss the clinical benefits and potential challenges of using nanocarrier-delivered small interfering RNA to treat chemotherapy-resistant ovarian cancer. We aim to elicit collaborative studies on nanocarrier-delivered small interfering RNA to improve the long-term survival rate and quality of life of patients with ovarian cancer. This article is categorized under: RNA Methods > RNA Nanotechnology Regulatory RNAs/RNAi/Riboswitches > RNAi: Mechanisms of Action.

Responsive and activable nanomedicines for remodeling the tumor microenvironment

Here we describe two protocols for the construction of responsive and activable nanomedicines that regulate the tumor microenvironment (TME). The TME is composed of all non-cellular and cellular components surrounding a tumor, including the surrounding blood vessels, immune cells, fibroblasts, signaling molecules, and extracellular matrix and has a crucial role in tumor initiation, growth, and metastasis. Owing to the relatively stable properties of the TME compared to tumor cells, which exhibit frequent genetic mutations and epigenetic changes, therapeutic strategies targeting the TME using multifunctional nanomedicines hold great potential for anti-tumor therapy. By regulating tumor-associated platelets and pancreatic stellate cells (PSCs), the two major players in the TME, we can effectively manipulate the physiological barriers for enhanced drug delivery and significantly improve the tumor penetration and therapeutic efficacy of chemotherapeutics. The preparation and characterization of the multifunctional nanoparticles takes ~10 h for tumor-associated platelet regulation and 16 h for PSC regulation. These nanoformulations can be readily applied to regulate other components in the TME to realize synergistic or additive anti-tumor activity.

A label-free immunosensor for the detection of a new lung cancer biomarker, GM2 activator protein, using a phosphomolybdic acid/polyethyleneimine coated gold nanoparticle composite

A novel electrochemical immunosensor for the detection of a new lung cancer biomarker based on a polyoxometalate-adsorbed poly(ethylenimine)-coated gold nanoparticle modified electrode.

Parallel Multiparameter Study of PEI-Functionalized Gold Nanoparticle Synthesis for Biomedical Applications: Part 2. Elucidating the Role of Surface Chemistry and Polymer Structure in Performance

Elucidating the polyethyleneimine (PEI) chemistry to predictively and reproducibly synthesize gold nanoparticle (AuNP)-PEI conjugates with desired properties has been elusive despite evaluation in numerous studies and reported enhanced properties. The lack of reproducible methods to control the core size and stability has led to contradictory results for performance and safety; thus, advancement of the conjugate platform for commercial use has likely been hindered. Recently, we reported a robust, reproducible method for synthesizing PEI-functionalized AuNPs (Au-PEIs), providing an opportunity to investigate structure-function relationships and to further investigate synthesis parameters affecting performance, where only materials stable in biological media are candidates for use. The properties of Au-PEIs prepared by the optimized reduction of HAuCl₄ using four different structural variants of PEI changed significantly with the PEI molar mass and backbone form (branched or linear). In the present study using our previously reported synthesis procedure, comprehensive analysis of properties such as size distribution, surface plasmon resonance (SPR), morphological state, surface functionality, and the shelf life has been systematically evaluated to elucidate the role of surface chemistry and reactive groups involved in conjugation, as a function of conjugate size and morphology. Being important for commercial adoption, the chemistry was related to the observed colloidal stability of the product in relevant media, including exposure to physiological variables such as salt, pH, proteins, and thermal changes. Overall, this work advances progress toward smart design of engineered nanoscale drug delivery systems and devices by providing unreported details of contributions affecting formation, stability, and fate.

Actively targeted gold nanoparticle composites improve behavior and cognitive impairment in Parkinson's disease mice

Parkinson's disease (PD) is characterized by motor and non-motor symptoms, primarily affecting dopaminergic neurons (DAergic neurons) in substantia nigra (SN). However, it is still very challenging to identify new drugs that not only inhibit motor dysfunction but also improve non-motor dysfunction. It has been identified as a potential PD treatment that the inhibition of α-syn aggregation could decrease the death of DAergic neurons in SN. In this study, we synthesized gold nanoparticle composites (NPs) that were loaded with plasmid DNA (pDNA) to inhibit α-syn expression. In vivo, our results showed that NPs improved tyrosine hydroxylase (TH) levels and decreased aggregation of α-syn in the SN. Additionally, NPs attenuated motor dysfunction and exploration ability declined. Moreover, NPs reversed the inhibition of long-term potentiation (LTP) and improved non-motor dysfunction in PD mice. These results indicated that NPs had significantly neuroprotective effects not only in motor, but also in non-motor dysfunction to PD mice, providing a new strategy for gene therapy in PD.

Enhanced Cancer DNA Vaccine via Direct Transfection to Host Dendritic Cells Recruited in Injectable Scaffolds

Deoxyribonucleic acid (DNA) vaccines are a promising cancer immunotherapy approach. However, effective delivery of DNA to antigen-presenting cells (e.g., dendritic cells (DCs)) for the induction of an adaptive immune response is limited. Conventional DNA delivery via intramuscular, intradermal, and subcutaneous injection by hypodermal needles shows a low potency and immunogenicity. Here, we propose the enhanced cancer DNA vaccine by direct transfection to the high number of DCs recruited into the chemoattractant-loaded injectable mesoporous silica microrods (MSRs). Subcutaneous administration of the MSRs mixed with tumor-antigen coding DNA polyplexes resulted in DC recruitment in the macroporous space of the scaffold formed by the spontaneous assembly of high-aspect-ratio MSRs, thereby allowing for enhanced cellular uptake of antigen-coded DNA by host DCs. The MSR scaffolds delivering the DNA vaccine trigger a more robust DC activation, antigen-specific CD8⁺ T cell response, and Th1 immune response compared to the bolus DNA vaccine. Additionally, the immunological memory can be induced with a single administration of the vaccine. The combination of the vaccination and antiprogrammed cell death-1 antibody significantly eliminates established lung metastasis. These results indicate that MSRs serve as a powerful platform for DNA vaccine delivery to DCs for effective cancer immunotherapy.

New Insights into Biocompatible Iron Oxide Nanoparticles: A Potential Booster of Gene Delivery to Stem Cells

Gene delivery to stem cells is a critical issue of stem cells-based therapies, still facing ongoing challenges regarding efficiency and safety. Recent advances in the controlled synthesis of biocompatible magnetic iron oxide nanoparticles (IONPs) have provided a powerful nanotool for assisting gene delivery to stem cells. However, this field is still at an early stage, with well-designed and scalable IONPs synthesis highly desired. Furthermore, the potential risks or bioeffects of IONPs on stem cells are not completely figured out. Therefore, in this review, the updated researches focused on the gene delivery to stem cells using various designed IONPs are highlighted. Additionally, the impacts of the physicochemical properties of IONPs, as well as the magnetofection systems on the gene delivery performance and biocompatibility are summarized. Finally, challenges attributed to the potential impacts of IONPs on the biologic behaviors of stem cells and the large-scale productions of uniform IONPs are emphasized. The principles and challenges summarized in this review provide a general guidance for the rational design of IONPs-assisted gene delivery to stem cells.

Gene Therapy and Photothermal Therapy of Layer-by-Layer Assembled AuNCs /PEI/miRNA/ HA Nanocomplexes

BACKGROUND

MicroRNA (miRNA) therapy, which was widely considered to treat a series of cancer, has been confronted with numerous obstacles to being delivered into target cells because of its easy biodegradation and instability.

METHODS

In this research, we successfully constructed 11-mercaptoundecanoic acid modified gold nanocages (AuNCs)/polyethyleneimine (PEI)/miRNA/hyaluronic acid (HA) complexes (abbreviated as AuNCs/PEI/miRNA/HA) using a layer-by-layer method for target-specific intracellular delivery of miRNA by HA receptor mediated endocytosis.

RESULTS

The results of UV spectra, hydrodynamic diameter and zeta potential analyses confirmed the formation of AuNCs/PEI/ miRNA/HA complex with its average particle size of ca. 153 nm and surface charge of ca. -9.43 mV. Next, we evaluated the antitumor effect of the nanocomplex mediated by the combination of gene therapy and photothermal therapy (PTT) against hepatocellular carcinoma (HCC) in vitro.

CONCLUSION

Our experimental results indicated that the AuNCs/PEI/miRNA/HA complex effectively delivered miRNA to the target cells and its antitumor effect was significantly enhanced by the combination of gene therapy and photothermal therapy. In addition, anti-miR-181b could promote Bel-7402 cell arrest in S phase and improve TIMP-3 mRNA expression. All these results suggested that AuNCs/PEI/miRNA/HA gene delivery system with combination of gene therapy and photothermal therapy might be exploited for HCC treatment.

Construction of gold-siRNA NPR1 nanoparticles for effective and quick silencing of NPR1 in Arabidopsis thaliana

In recent years, gold nanoparticles (AuNPs) have been widely used as gene silencing agents and therapeutics for treatment of cancers due to their high transfection efficiency and lack of cytotoxicity, but their roles in gene silencing in plants have not yet been reported. Here, we report synthesis of AuNPs-branched polyethylenimine and its integration with the small interfering RNAs (siRNA) of NPR1 to form a AuNPs-siRNA_NPR1 compound. Our results showed that AuNPs-siRNA_NPR1 was capable of infiltrating into Arabidopsis cells. AuNPs-siRNA_NPR1 silenced 80% of the NPR1 gene in Arabidopsis. Bacteriostatic and ion leakage experiments suggest that the NPR1 gene in Arabidopsis leaves was silenced by AuNPs-siRNA_NPR1. In Columbia-0 plants, compared with the control group treated with buffer solution, the AuNPs-siRNA_NPR1 treatment significantly increased the number of colonies and cell death, and the leaves turned yellow, similar to the phenotype of the npr1 leaves. These results indicated this AuNPs-siRNA_NPR1 silencing the NPR1 gene method is simple, effective and quick (3 days), and a powerful tool to study gene functions in plants.

Gold nanoparticles (AuNPs) have been widely used as gene silencing agents and therapeutics for treatment due to their high transfection efficiency and lack of cytotoxicity, but their roles in gene silencing in plants have not yet been reported.

Polymer-mediated gene therapy: Recent advances and merging of delivery techniques

The ability to safely and precisely deliver genetic materials to target sites in complex biological environments is vital to the success of gene therapy. Numerous viral and nonviral vectors have been developed and evaluated for their safety and efficacy. This study will feature progress in synthetic polymers as nonviral vectors, which benefit from their chemical versatility, biocompatibility, and ability to carry both therapeutic cargo and targeting moieties. The combination of synthetic gene carrying constructs with advanced delivery techniques promises new therapeutic options for treating and curing genetic disorders. This article is characterized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Influence of synthesis methods on the internalization of fluorescent gold nanoparticles into glioblastoma stem-like cells

Glioblastoma (GBM) is an aggressive disease with currently no satisfying treatment option available. GBM cells with stem cell properties are thought to be responsible for the initiation and propagation of the disease, as well as main contributors to the emergence of therapy resistance. In this work, we developed a novel method to synthesize fluorescent gold nanoparticles as potential drug and gene delivery systems for GBM therapy, able to penetrate three-dimensional stem cell selected patient-derived GBM neurosphere systems in vitro. By using polyethylene imine (PEI) as a stabilizer and reducing agent, as well as fluorescein isothiocyanate (FITC) as a fluorescent marker, our fully in-house developed fluorescent gold nanoparticles (AuPEI-FITC NPs) with core sizes between 3 and 6 nm were obtained via a fast microwave-assisted reaction. Cytotoxicity, adsorption and internalization of AuPEI-FITC NPs into the cell lines JHH520, 407 and GBM1 were investigated using the cellular growth assay and fluorescence-activated cell sorting (FACS) analysis. AuPEI-FITC NPs showed no apparent cytotoxicity and an uptake in cells of up to ~80%. A differentiation between surface-bound and internalized AuPEI-FITC NPs was possible by quenching extracellular signals. This resulted in a maximal internalization degree of 61%, which depends highly on the synthesis method of the nanoparticles and the cell type tested. The best internalization was found for AuPEI-FITC1 which was prepared in a one pot reaction from KAuCl₄, PEI and FITC. Thus, appropriately synthesized AuPEI-FITC NPs show great potential as vehicles to transport DNA or drugs in GBM cells.

Role of Cholesterol Conjugation in the Antibacterial Photodynamic Therapy of Branched Polyethylenimine-Containing Nanoagents

Photodynamic therapy is a promising approach for fighting bacterial infections because it can induce few side effects, develop no drug resistance, and realize precise treatment. However, most photosensitizers (PSs) have the disadvantages of poor water-solubility, severe self-quenching, and potential toxicity. Here, the cationic polymer polyethyleneimine (PEI) was used to prepare a cholesterol- and chlorin e6 (Ce6, a common PS)-conjugated compound via the carboxyl-amine reaction or the acyl chloride-amine reaction (abbreviated as Chol-PEI-Ce6). The as-prepared Chol-PEI-Ce6 molecules can self-assemble into close-to-spherical nanoparticles (NPs) with an average diameter of ∼15 nm and can bind to the bacterial surfaces via the synergistic hydrophobic insertion of the cholesterol moieties and electrostatic interaction between the cationic amine groups of PEI and the bacterial surfaces. Upon light irradiation, the NPs can effectively inactivate both Gram-positive and Gram-negative bacteria. Besides, the interaction between Chol-PEI-Ce6 NPs and bacteria markedly enhances the production of intracellular reactive oxygen species after light irradiation, which may account for the excellent antibacterial performance of the NPs. More importantly, the NPs possess negligible dark cytotoxicity and good hemocompatibility. Therefore, the present work may have strong implications for developing novel antibacterial agents to fight against bacterial infections.

Electrocatalytic synthesis of black tin oxide nanomaterial as photothermal agent for cancer therapy

Photothermal therapy (PTT) is among the popular approach for treating solid tumours. The rapid killing of cancer cells under the influence of infrared radiation by a rapid increase in the temperature of the remote area now demands external agents with high photothermal transduction efficiency (PTE). Despite their improved PTE, black nanomaterials such as black phosphorus and titanium oxide are unable to meet the challenges in the physiological conditions. To address this major concern, we have developed black tin oxide (bSnO) with enhanced capabilities to respond in the physiological milieu. To make the synthesis cost-effective and eco-friendly, we have used electrochemical oxidation at 5 V and 100 mA to achieve ∼15 nm nanoparticle of bSnO. The as-synthesized bSnO exhibited high NIR absorption as well as high photothermal transduction efficiency. To circumvent the low aqueous solubility and photostability, bSnO was functionalized with polyethyleneimine (PEI). Upon exposure to 808 nm laser for ∼8-10 min, the temperature of the bSnO@PEI solution reached ∼58.5 °C. PTE of bSnO@PEI was calculated to be 51.2%. Owing to its high biological compatibility, tin offers relatively better stability when exposed to cancer cells in vitro and in vivo. In comparison to other black nanomaterials, bSnO@PEI was found to exhibit better response under NIR irradiance for non-invasive photothermal therapy of cancer.

Biofriendly and Regenerable Emotional Monitor from Interfacial Ultrathin 2D PDA/AuNPs Cross-linking Films

Well-designed 2D materials with ultrathin structures show great potential for humidity-sensing performance owing to their high surface-volume ratio and a great number of exposed atoms on the surface. However, some sensing elements employed for healthcare applications may be considered as potentially risky, such as inflammation, granuloma formation, and carcinogenesis. Herein, we explored biofriendly humidity-sensing characteristics inspired by the great biocompatibility and conductivity of hyperbranched polyethyleneimine-capped gold nanoparticles and cross-linked with polydopamine from the adhesive proteins in mussels. It was successfully employed into two kinds of wearable devices, sports watches and breathing masks, for real-time recording humidity's fluctuation in expiration and sweat with changes of individual's crying, laughing, nervous, sleeping, training, and cold states. The wearable devices allow us to monitor individual's physical activities and emotional states well, suggesting a promising prospect in safe, reusable, long term, and noncontact human health monitoring applications.

Multifunctionality of gold nanoparticles: Plausible and convincing properties

In a couple of decades, nanotechnology has become a trending area in science due to it covers all subject that combines diverse range of fields including but not limited to chemistry, physics and medicine. Various metal and metal oxide nanomaterials have been developed for wide range applications. However, the application of gold nanostructures and nanoparticles has been received more attention in various biomedical applications. The unique property of gold nanoparticles (AuNPs) is surface plasmon resonance (SPR) that determine the size, shape and stability. The wide surface area of AuNPs eases the proteins, peptides, oligonucleotides, and many other compounds to tether and enhance the biological activity of AuNPs. AuNPs have multifunctionality including antimicrobial, anticancer, drug and gene delivery, sensing applications and imaging. This state-of-the-art review is focused on the role of unique properties of AuNPs in multifunctionality and its various applications.

Triggered RNAi Therapy Using Metal Inorganic Nanovectors

The administration of small interfering RNA (siRNA) is a very interesting therapeutic option to treat genetic diseases such as Alzheimer's or some types of cancer, but its effective delivery still remains a challenge. Herein, Au nanorod (GNR)-based platforms functionalized with polyelectrolyte layers were developed and analyzed as potential siRNA nanocarriers. The polymeric layers were successfully assembled on the particle surfaces by means of the layer-by-layer assembly technique through the alternating deposition of oppositely charged poly(styrene)sulfonate, PSS, poly(lysine), PLL, and siRNA biopolymers, with a final hyaluronic acid layer in order to provide the nanoconstructs with a potential targeting ability as well as colloidal stability in physiological medium. Once the hybrid nanocarriers were obtained, the cargo release, their colloidal stability in physiological-relevant media, cytotoxicity, cellular internalization and uptake, and knockdown activity were studied. The present hybrid particles release the genetic material inside cells by means of a protease-assisted and/or a light-triggered release mechanism in order to control the delivery of the oligonucleotides on demand. In addition, the hybrid nanovectors were observed to be nontoxic to cells and could efficiently deliver the genetic material in the cell cytoplasms. The GNR-based nanocarriers proposed here can provide a suitable environment to load and protect a sufficient amount of the genetic material to allow an efficient and sustained knockdown gene expression for long (up to 93% for 72 h), thanks to the slow degradation of PLL, without the observation of adverse side toxic effects. It was also found that the silencing activity was enhanced with the number of siRNA layers assembled in the nanoplatforms.