Polycation-functionalized gold nanoparticles with different morphologies for superior gene transfection

Biomaterial-based gene therapy

Gene therapy, a medical approach that involves the correction or replacement of defective and abnormal genes, plays an essential role in the treatment of complex and refractory diseases, such as hereditary diseases, cancer, and rheumatic immune diseases. Nucleic acids alone do not easily enter the target cells due to their easy degradation in vivo and the structure of the target cell membranes. The introduction of genes into biological cells is often dependent on gene delivery vectors, such as adenoviral vectors, which are commonly used in gene therapy. However, traditional viral vectors have strong immunogenicity while also presenting a potential infection risk. Recently, biomaterials have attracted attention for use as efficient gene delivery vehicles, because they can avoid the drawbacks associated with viral vectors. Biomaterials can improve the biological stability of nucleic acids and the efficiency of intracellular gene delivery. This review is focused on biomaterial-based delivery systems in gene therapy and disease treatment. Herein, we review the recent developments and modalities of gene therapy. Additionally, we discuss nucleic acid delivery strategies, with a focus on biomaterial-based gene delivery systems. Furthermore, the current applications of biomaterial-based gene therapy are summarized.

Applications and perspectives of quaternized cellulose, chitin and chitosan: A review

Recently, increasing attention has been paid to natural polysaccharides for their low cost, biocompatibility and biodegradability. Quaternization is a modification method to improve the solubility and antibacterial ability of natural polysaccharides. Water-soluble derivatives of cellulose, chitin and chitosan offer the prospect of diverse applications in a wide range of fields, such as antibacterial products, drug delivery, wound healing, sewage treatment and ion exchange membranes. By combining the inherent properties of cellulose, chitin and chitosan with the inherent properties of the quaternary ammonium groups, new products with multiple functions and properties can be obtained. In this review, we summarized the research progress in the applications of quaternized cellulose, chitin and chitosan in recent five years. Moreover, ubiquitous challenges and personal perspectives on the further development of this promising field are also discussed.

Design strategies, surface functionalization, and environmental remediation potentialities of polymer-functionalized nanocomposites

Inorganic nanoparticles (NPs) have a tunable shape, size, surface morphology, and unique physical properties like catalytic, magnetic, electronic, and optical capabilities. Unlike inorganic nanomaterials, organic polymers exhibit excellent stability, biocompatibility, and processability with a tailored response to external stimuli, including pH, heat, light, and degradation properties. Nano-sized assemblies derived from inorganic and polymeric NPs are combined in a functionalized composite form to import high strength and synergistically promising features not reflected in their part as a single constituent. These new properties of polymer/inorganic functionalized materials have led to emerging applications in a variety of fields, such as environmental remediation, drug delivery, and imaging. This review spotlights recent advances in the design and construction of polymer/inorganic functionalized materials with improved attributes compared to single inorganic and polymeric materials for environmental sustainability. Following an introduction, a comprehensive review of the design and potential applications of polymer/inorganic materials for removing organic pollutants and heavy metals from wastewater is presented. We have offered valuable suggestions for piloting, and scaling-up polymer functionalized nanomaterials using simple concepts. This review is wrapped up with a discussion of perspectives on future research in the field.

Length-Controlled Nanofiber Micelleplexes as Efficient Nucleic Acid Delivery Vehicles

Micelleplexes show great promise as effective polymeric delivery systems for nucleic acids. Although studies have shown that spherical micelleplexes can exhibit superior cellular transfection to polyplexes, to date there has been no report on the effects of micelleplex morphology on cellular transfection. In this work, we prepared precision, length-tunable poly(fluorenetrimethylenecarbonate)-b-poly(2-(dimethylamino)ethyl methacrylate) (PFTMC₁₆-b-PDMAEMA₁₃₁) nanofiber micelleplexes and compared their properties and transfection activity to those of the equivalent nanosphere micelleplexes and polyplexes. We studied the DNA complexation process in detail via a range of techniques including cryo-transmission electron microscopy, atomic force microscopy, dynamic light scattering, and ζ-potential measurements, thereby examining how nanofiber micelleplexes form, as well the key differences that exist compared to nanosphere micelleplexes and polyplexes in terms of DNA loading and colloidal stability. The effects of particle morphology and nanofiber length on the transfection and cell viability of U-87 MG glioblastoma cells with a luciferase plasmid were explored, revealing that short nanofiber micelleplexes (length < ca. 100 nm) were the most effective delivery vehicle examined, outperforming nanosphere micelleplexes, polyplexes, and longer nanofiber micelleplexes as well as the Lipofectamine 2000 control. This study highlights the potential importance of 1D micelleplex morphologies for achieving optimal transfection activity and provides a fundamental platform for the future development of more effective polymeric nucleic acid delivery vehicles.

Recent developments in the use of gold and silver nanoparticles in biomedicine

Gold and silver nanoparticles (NPs) are widely used in the biomedical research both in the therapeutic and the sensing/diagnostics fronts. Both metals share some common optical properties with surface plasmon resonance being the most widely exploited property in therapeutics and diagnostics. Au NPs exhibit excellent light‐to‐heat conversion efficiencies and hence have found applications primarily in precision oncology, while Ag NPs have excellent antibacterial properties which can be harnessed in biomaterials' design. Both metals constitute excellent biosensing platforms owing to their plasmonic properties and are now routinely used in various optical platforms. The utilization of Au and Ag NPs in the COVID‐19 pandemic was rapidly expanded mostly in biosensing and point‐of‐care platforms and to some extent in therapeutics. In this review article, the main physicochemical properties of Au and Ag NPs are discussed with selective examples from the recent literature.

This article is categorized under:

Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease

Diagnostic Tools > In Vitro Nanoparticle‐Based Sensing

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology

Gold nanomaterials for oral cancer diagnosis and therapy: Advances, challenges, and prospects

Early diagnosis and treatment of oral cancer are vital for patient survival. Since the oral cavity accommodates the second largest and most diverse microbiome community after the gut, the diagnostic and therapeutic approaches with low invasiveness and minimal damage to surrounding tissues are keys to preventing clinical intervention-related infections. Gold nanoparticles (AuNPs) are widely used in the research of cancer diagnosis and therapy due to their excellent properties such as surface-enhanced Raman spectroscopy, surface plasma resonance, controlled synthesis, the plasticity of surface morphology, biological safety, and stability. AuNPs had been used in oral cancer detection reagents, tumor-targeted therapy, photothermal therapy, photodynamic therapy, and other combination therapies for oral cancer. AuNPs-based noninvasive diagnosis and precise treatments further reduce the clinical intervention-related infections. This review is focused on the recent advances in research and application of AuNPs for early screening, diagnostic typing, drug delivery, photothermal therapy, radiotherapy sensitivity treatment, and combination therapy of oral cancer. Distinctive reports from the literature are summarized to highlight the latest advances in the development and application of AuNPs in oral cancer diagnosis and therapy. Finally, this review points out the challenges and prospects of possible applications of AuNPs in oral cancer diagnosis and therapy.

pH-Responsive hyaluronic acid-cloaked polycation/gold nanohybrids for tumor-targeted synergistic photothermal/gene therapy

The combination of photothermal therapy (PTT) and gene therapy (GT) has attracted intense interest in cancer treatment. However, the lack of long circulation and active tumor targeting reduces the therapeutic efficacy of complementary PTT/GT. In this work, hyaluronic acid (HA)-cloaked gold nanorods-PGED (prepared by ring-opening of polyglycidyl methacrylate (PGMA) with ethylenediamine (ED))/pDNA (AP/pDNA-HA) complexes were prepared to achieve long circulation and tumor targeting for photoacoustic imaging (PAI)-guided synergistic PTT/GT. Gold nanorods endow the complexes with photothermal effect and PAI function. Benefiting from the HA cloak, the AP/pDNA-HA complexes exhibit excellent stability, biocompatibility, long circulation behavior and active targeting. In addition, the pH-responsive characteristic of the Schiff base bonds helps the AP/pDNA-HA complexes to effectively escape from the endosome/lysosome. The antioncogene p53 was employed to investigate the gene transfection efficiency of the delivery system both in vitro and in vivo. The superiority of synergistic PTT/GT is established in a mouse 4T1 breast tumor model. The current study provides a facile strategy for constructing multifunctional gene delivery systems with long circulation and tumor targeting features, which can achieve effective imaging-guided synergistic tumor treatment.

Precision polymer nanofibers with a responsive polyelectrolyte corona designed as a modular, functionalizable nanomedicine platform

We describe the development of a modular, functionalizable platform for biocompatible core-shell block copolymer nanofibers of controlled length (22 nm – 1.3 μm) and low dispersity produced via living crystallization-driven...

Gold Nanorods: The Most Versatile Plasmonic Nanoparticles

Gold nanorods (NRs), pseudo-one-dimensional rod-shaped nanoparticles (NPs), have become one of the burgeoning materials in the recent years due to their anisotropic shape and adjustable plasmonic properties. With the continuous improvement in synthetic methods, a variety of materials have been attached around Au NRs to achieve unexpected or improved plasmonic properties and explore state-of-the-art technologies. In this review, we comprehensively summarize the latest progress on Au NRs, the most versatile anisotropic plasmonic NPs. We present a representative overview of the advances in the synthetic strategies and outline an extensive catalogue of Au-NR-based heterostructures with tailored architectures and special functionalities. The bottom-up assembly of Au NRs into preprogrammed metastructures is then discussed, as well as the design principles. We also provide a systematic elucidation of the different plasmonic properties associated with the Au-NR-based structures, followed by a discussion of the promising applications of Au NRs in various fields. We finally discuss the future research directions and challenges of Au NRs.

Organic/Inorganic Self-Assembled Hybrid Nano-Architectures for Cancer Therapy Applications

Since the conceptualization of nanomedicine, numerous nanostructure-mediated drug formulations have progressed into clinical trials for treating cancer. However, recent clinical trial results indicate such kind of drug formulations has a limited improvement on the antitumor efficacy. This is due to the biological barriers associated with those formulations, for example, circulation stability, extravasation efficiency in tumor, tumor penetration ability, and developed multi-drug resistance. When employing for nanomedicine formulations, pristine organic-based and inorganic-based nanostructures have their own limitations. Accordingly, organic/inorganic (O/I) hybrids have been developed to integrate the merits of both, and to minimize their intrinsic drawbacks. In this context, the recent development in O/I hybrids resulting from a self-assembly strategy will be introduced. Through such a strategy, organic and inorganic building blocks can be self-assembled via either chemical covalent bonds or physical interactions. Based on the self-assemble procedure, the hybridization of four organic building blocks including liposomes, micelles, dendrimers, and polymeric nanocapsules with five functional inorganic nanoparticles comprising gold nanostructures, magnetic nanoparticles, carbon-based materials, quantum dots, and silica nanoparticles will be highlighted. The recent progress of these O/I hybrids in advanced modalities for combating cancer, such as, therapeutic agent delivery, photothermal therapy, photodynamic therapy, and immunotherapy will be systematically reviewed.

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.

Polycation-Carbon Nanohybrids with Superior Rough Hollow Morphology for the NIR-II Responsive Multimodal Therapy

Polymer-inorganic hybrid nanomaterials have attracted much attention for the multimodal cancer therapy, while it is still desirable to explore hybrids with superior morphologies for two or more therapeutic modalities. In this work, four types of carbon nanoparticles with distinct morphologies were prepared by an elaborate template-carbonization corrosion process and then functionalized with a similar amount of the superior polycationic gene vector, CD-PGEA [consisting of one β-cyclodextrin core (CD) and two cationic ethanolamine-functionalized poly(glycidyl methacrylate) (PGEA) arms] to evaluate the morphology-influenced gene and photothermal (PT) therapy. Benefiting from the starting rough hollow nanosphere (RHNS) core, the resultant nanohybrids RHNS-PGEA exhibited the highest gene transfection (including luciferase, fluorescent protein plasmid, and antioncogene p53) and NIR PT conversion efficiency among the four types of nanohybrids. Moreover, the efficient PT effect endowed RHNS-PGEA with PA imaging enhancement and an effective imaging guide for the tumor therapy. In addition, anticancer drug 10-hydroxy camptothecin was successfully encapsulated in RHNS with polycation coating, which also displayed the second near-infrared (NIR-II)-responsive drug release. Taking advantages of the superior gene delivery/PT effect and NIR-II-enhanced drug delivery, RHNS-PGEA realized a remarkable therapeutic effect of trimodal gene/PT/chemotherapy of malignant breast cancer treatment in vitro and in vivo. The present work offers a promising approach for the rational design of polymer-inorganic nanohybrids with superior morphology for the multimodal cancer therapy.

Organic/inorganic nanohybrids as multifunctional gene delivery systems

In this review, we summarize the rational design and versatile application of organic/inorganic hybrid gene carriers as multifunctional delivery systems. Organic/inorganic nanohybrids with both organic and inorganic components in one nanoparticle have attracted intense attention because of their favorable properties. Particularly, nanohybrids comprising cationic polymers and inorganic nanoparticles are considered to be promising candidates as multifunctional gene delivery systems. In this review, we begin with an introduction of gene delivery and gene carriers to demonstrate the incentive for fabricating nanohybrids as multifunctional carriers. Next, the construction strategies and morphology effects of organic/inorganic hybrid gene carriers are summarized and discussed. Both sections provide valuable information for the design and synthesis of hybrid gene carriers with superior properties. Finally, an overview is provided of the application of nanohybrids as multifunctional gene carriers. Diverse therapies and versatile imaging-guided therapies have been achieved via the rational design of nanohybrids. In addition to a simple combination of the functions of organic and inorganic components, the performances arising from the synergistic effects of both components are considered to be more intriguing. In summary, this review might offer guidance for the understanding of organic/inorganic nanohybrids as multifunctional gene delivery systems.

Core-independent approach for polymer brush-functionalised nanomaterials with a fluorescent tag for RNA delivery

A core-independent approach for the design of polymer brush-functionalised nanomaterials with a fluorescent tag for RNA delivery.

Size-dependent neutralizing activity of gold nanoparticle-based subunit vaccine against dengue virus

Dengue results in substantial human morbidity and significant socio-economic impacts, but a specific dengue therapeutic is not available. The currently available dengue vaccine has low efficacy and high rate of adverse effects, necessitating different strategies for the development of a safer and more efficient vaccine against dengue virus. We describe here a hybrid combination of different-sized gold nanoparticles (AuNPs) and domain III of envelope glycoprotein derived from serotype 2 of dengue virus (EDIII) as dengue subunit vaccine. The efficacy of the EDIII-functionalized AuNPs (AuNP-E) to induce neutralizing antibody in BALB/c mice is evaluated. Obtained results show that AuNP-E induced a high level of antibody which mediates serotype-specific neutralization of dengue virus. More importantly, the level of antibody is dependent on both the size of AuNPs and the concentration of AuNP-E, implicating the possibility to modulate it through adjusting these parameters. These results represent an important step towards the development of tetravalent AuNP-based subunit dengue vaccine.

STATEMENT OF SIGNIFICANCE

This research presents a novel subunit vaccine against dengue virus using a hybrid comprising gold nanoparticles (AuNPs) and domain III of envelop protein (EDIII). We proved the neutralizing activity of anti-EDIII antibody induced in immunized mice on Dengue virus serotype 2 in an AuNP core size and concentration dependent manner. The hybrid concept behind this work could also be adopted for the development of a tetravalent vaccine against four serotypes of Dengue virus.

Biocompatible protamine sulfate@silicon nanoparticle-based gene nanocarriers featuring strong and stable fluorescence

The development of biocompatible and fluorescent gene carriers is of particular importance in the gene-delivery field. Taking advantage of the unique optical properties (e.g., strong and robust fluorescence) of silicon nanoparticles (SiNPs), as well as the excellent biocompatibility of silicon and protamine sulfate (PS, approved by the U.S. Food and Drug Administration (FDA) for clinical use), we herein present a type of PS-modified SiNP (PS@SiNP)-based gene carrier. Plasmid DNA (pDNA) with negative charges can be effectively bound onto the surface of the as-prepared fluorescent PS@SiNP-based gene carriers via electrostatic interactions. In particular, such resultant gene carriers possess stable and high fluorescence (photoluminescent quantum yield (PLQY): ∼25%). In addition, the PS@SiNP-based gene carriers show minimal toxic effects on normal mitochondrial metabolic activity (e.g., human retinal pigment epithelial (ARPE-19) cells preserve ∼90% of their cell viability after a 48 h incubation with the resultant carriers). Based on tracking the strong and stable fluorescence signals of SiNPs, the dynamic behavior of the PS@SiNP-based gene carriers in live cells (e.g., clathrin-mediated endocytosis, lysosomal escape, pDNA release, etc.) is investigated in a long-term manner, providing valuable information for understanding the intracellular behavior of gene vectors and designing high-efficacy gene carriers.

Current status and future developments in preparation and application of nonspherical polymer particles

Nonspherical polymer particles (NPPs) are nano/micro-particulates of macromolecules that are anisotropic in shape, and can be designed anisotropic in chemistry. Due to shape and surface anisotropies, NPPs bear many unique structures and fascinating properties which are distinctly different from those of spherical polymer particles (SPPs). In recent years, the research on NPPs has surprisingly blossomed in recent years, and many practical materials based on NPPs with potential applications in photonic device, material science and biomedical engineering have been generated. In this review, we give a systematic, balanced and comprehensive summary of the main aspects of NPPs related to their preparation and application, and propose perspectives for the future developments of NPPs.

Multifunctional hybrids with versatile types of nanoparticles via self-assembly for complementary tumor therapy

Self-assembly is a promising method for the construction of multifunctional nanohybrids for biomedical application. In this work, self-assembled multifunctional nanohybrids with a controllable disassembly property have been successfully fabricated. By modification with cyclodextrin (CD)-decorated ethylenediamine-functionalized poly(glycidyl methacrylate) (PGED), CD groups and polycations were conjugated onto Au nanorods (Au NRs) or Fe3O4 nanoparticles (denoted as Au-PGED-CD or Fe3O4-PGED-CD), and different SiO2@Fe3O4-PGED (SFP) or SiO2@Au-PGED (SAP) nanohybrids were readily fabricated by the host-guest interaction between Au-PGED-CD or Fe3O4-PGED-CD and adamantyl (Ad)-functionalized chiral silica NRs under mild conditions. The DNA condensation ability of the polycation, the photothermal effects of Au NRs or Fe3O4 nanoparticles, as well as the unique structure of chiral silica NRs were integrated into one nanohybrid. Such nanohybrids have high gene transfection efficiency and low cytotoxicity. The photothermal effects of the nanohybrids could be utilized for photothermal therapy, and also could induce the disassembly of the nanohybrids, which is beneficial for DNA release. The nanohybrids with good transfection performance and excellent photothermal effects were further applied for multimodal therapy. This work presents a flexible strategy for the fabrication of multifunctional nanoplatforms with integration of the advantages of various types of nanoparticles.

Neuroprotective effect of gold nanoparticles composites in Parkinson's disease model

Parkinson's disease (PD) is second most common neurodegenerative disorder worldwide. Although drugs and surgery can relieve the symptoms of PD, these therapies are incapable of fundamentally treating the disease. For PD patients, over-expression of α-synuclein (SNCA) leads to the death of dopaminergic neurons. This process can be prevented by suppressing SNCA over-expression through RNA interference. Here, we successfully synthesized gold nanoparticles (GNP) composites (CTS@GNP-pDNA-NGF) via the combination of electrostatic adsorption and photochemical immobilization, which could load plasmid DNA (pDNA) and target specific cell types. GNP was transfected into cells via endocytosis to inhibiting the apoptosis of PC12 cells and dopaminergic neurons. Simultaneously, GNP composites are also used in PD models in vivo, and it can successfully cross the blood-brain barrier by contents of GNP in the mice brain. In general, all the works demonstrated that GNP composites have good therapeutic effects for PD models in vitro and in vivo.

Ultrasensitive microfluidic paper-based electrochemical/visual biosensor based on spherical-like cerium dioxide catalyst for miR-21 detection

In this work, an electrochemical biosensor based on Au nanorods (NRs) modified microfluidic paper-based analytical devices (μPADs) were constructed for sensitive detection of microRNA (miRNA) by using cerium dioxide - Au@glucose oxidase (CeO₂-Au@GOx) as an electrochemical probe for signal amplification. Au NRs were synthesized by in-situ growth method in μPADs surface to enhance the conductivity and modified hairpin probe through Au-S bonds. The construction of "the signal transducer layer" was carried out by GOx catalyzing glucose to produce H₂O₂, which was further electrocatalyzed by CeO₂. After the biosensor was constructed, an obvious electrochemical signal was observed from the reduction of H₂O₂. In order to make the detection more convincing, the visual detection was performed based on the oxidation of 3,3',5,5'-tetramethylbenzidine by H₂O₂ with the help of Exonuclease I. The electrochemical biosensor provided a wide linear range of 1.0fM to 1000fM with a relatively low detection limit of 0.434fM by the electrochemical measurement. Linear range of 10fM to 1000fM with a relatively low detection limit of 7.382fM was obtained by visual detection. The results indicated the proposed platform has potential utility for detection of miRNA.

Statistical versus block fluoropolymers in gene delivery

A statistical fluorocopolymer shows dramatically higher transfection efficiency in gene delivery than a block one.

Size-tunable uniform gold octahedra: fast synthesis, characterization, and plasmonic properties

Well-defined octahedral Au nanocrystals were facilely and precisely prepared in high yield by modified polyol process.

Photosensitizer cross-linked nano-micelle platform for multimodal imaging guided synergistic photothermal/photodynamic therapy

The multifunctional nano-micelle platform holds great promise to enhance the accuracy and efficiency of cancer diagnosis and therapy. In this work, an amphiphilic poly[(poly(ethylene glycol) methyl ether methacrylate)-co-(3-aminopropyl methacrylate)]-block-poly(methyl methacrylate) (P(PEGMA-co-APMA)-b-PMMA) block copolymer was synthesized by successive RAFT polymerizations and subsequent chemical modification. Then the multifunctional micelles with high solubility in physiological environments were developed by a self-assembly and crosslinking processes. The photosensitizer segment, 5,10,15,20-tetrakis (4-carboxyphenyl) porphyrin (TCPP), serves as a tetra-functional cross-linker, photodynamic agent, fluorescence indicator, as well as magnetic resonance (MR) contrast agent after labelling with manganese ions (Mn(2+)), while IR825 simultaneously locating in the interior of the fabricated micelles contributed to the photoacoustic (PA) imaging ability and the photothermal effect. The prepared nanoparticles show great stability in a physiological environment with uniform morphology and diameters of around 80 nm as disclosed by stability investigation, TEM and DLS analysis. IR825@P(PEGMA-co-APMA)-b-PMMA@TCPP/Mn nanoparticles displayed high in vivo tumor uptake with a long blood circulation half-life (∼3.64 h) by the EPR effect after intravenous (i.v.) injection, as revealed by fluorescence, MR and PA imaging models. In vivo anti-tumor effects were achieved via a combined photothermal and photodynamic therapy without noticeable dark toxicity, and this strategy was able to induce a remarkably improved synergistic therapeutic effect to both superficial and deep regions of tumors under mild conditions compared with either single photothermal or photodynamic mechanisms.

Efficient Transfection by Using PDMAEMA-Modified SiNWAs as a Platform for Ca(2+)-Dependent Gene Delivery

The major bottleneck for gene delivery lies in the lack of safe and efficient gene vectors and delivery systems. In order to develop a much safer and efficient transfection system, a novel strategy of combining traditional Ca(2+)-dependent transfection with cationic polymer poly(N,N-dimethylamino)ethyl methacrylate (PDMAEMA) modified silicon nanowire arrays (SiNWAs) was proposed in this work. Detailed studies were carried out on the effects of the PDMAEMA polymerization time, the Ca(2+) concentration, and the incubation time of Ca(2+)@DNA complex with PDMAEMA-modified SiNWAs (SN-PDM) on the gene transfection in the cells. The results demonstrated that the transfection efficiency of SN-PDM assisted traditional Ca(2+)-dependent transfection was significantly enhanced compared to those without any surface assistance, and SN-PDM with polymerization time 24 h exhibited the highest efficiency. Moreover, the optimal transfection efficiency was found at the system of a complex containing Ca(2+) (100 mM) and plasmid DNA (pDNA) incubated on SN-PDM for 20 min. Compared with unmodified SiNWAs, SN-PDM has little cytotoxicity and can improve cell attachment. All of these results demonstrated that SN-PDM could significantly enhance Ca(2+)-dependent transfection; this process depends on the amino groups' density of PDMAEMA on the surface, the Ca(2+) concentration, and the available Ca(2+)@DNA complex. Our study provides a potential novel and excellent means of gene delivery for therapeutic applications.

Well-Defined Peapod-like Magnetic Nanoparticles and Their Controlled Modification for Effective Imaging Guided Gene Therapy

Due to their unique properties, one-dimensional (1D) magnetic nanostructures are of great significance for biorelated applications. A facile and straightforward strategy to fabricate 1D magnetic structure with special shapes is highly desirable. In this work, well-defined peapod-like 1D magnetic nanoparticles (Fe3O4@SiO2, p-FS) are readily synthesized by a facile method without assistance of any templates, magnetic string or magnetic field. There are few reports on 1D gene carriers based on Fe3O4 nanoparticles. BUCT-PGEA (ethanolamine-functionalized poly(glycidyl methacrylate) is subsequently grafted from the surface of p-FS nanoparticles by atom transfer radical polymerization to construct highly efficient gene vectors (p-FS-PGEA) for effective biomedical applications. Peapod-like p-FS nanoparticles were proven to largely improve gene transfection performance compared with ordinary spherical Fe3O4@SiO2 nanoparticles (s-FS). External magnetic field was also utilized to further enhance the transfection efficiency. Moreover, the as-prepared p-FS-PGEA gene carriers could combine the magnetic characteristics of p-FS to well achieve noninvasive magnetic resonance imaging (MRI). We show here novel and multifunctional magnetic nanostructures fabricated for biomedical applications that realized efficient gene delivery and real-time imaging at the same time.

Gold nanoparticle size and shape influence on osteogenesis of mesenchymal stem cells

Gold nanoparticles (AuNPs) have been extensively explored for biomedical applications due to their advantages of facile synthesis and surface functionalization. Previous studies have suggested that AuNPs can induce differentiation of stem cells into osteoblasts. However, how the size and shape of AuNPs affect the differentiation response of stem cells has not been elucidated. In this work, a series of bovine serum albumin (BSA)-coated Au nanospheres, Au nanostars and Au nanorods with different diameters of 40, 70 and 110 nm were synthesized and their effects on osteogenic differentiation of human mesenchymal stem cells (hMSCs) were investigated. All the AuNPs showed good cytocompatibility and did not influence proliferation of hMSCs at the studied concentrations. Osteogenic differentiation of hMSCs was dependent on the size and shape of AuNPs. Sphere-40, sphere-70 and rod-70 significantly increased the alkaline phosphatase (ALP) activity and calcium deposition of cells while rod-40 reduced the ALP activity and calcium deposition. Gene profiling revealed that the expression of osteogenic marker genes was down-regulated after incubation with rod-40. However, up-regulation of these genes was found in the sphere-40, sphere-70 and rod-70 treatment. Moreover, it was found that the size and shape of AuNPs affected the osteogenic differentiation of hMSCs through regulating the activation of Yes-associated protein (YAP). These results indicate that the size and shape of AuNPs had an influence on the osteogenic differentiation of hMSCs, which should provide useful guidance for the preparation of AuNPs with defined size and shape for their biomedical applications.

Biodegradable PEI modified complex micelles as gene carriers with tunable gene transfection efficiency for ECs

In recent years, gene therapy has evoked an increasing interest in clinical treatments of coronary diseases because it is a potential strategy to realize rapid endothelialization of artificial vascular grafts. The balance of high transfection efficiency and low cytotoxicity of nonviral gene carriers is an important issue to be solved. In this study, we aim to establish a gene delivery system offering an elegant way to tune the transfection activity and cytotoxicity. Biodegradable complex micelles were prepared from polyethylenimine-b-poly(lactide-co-3(S)-methyl-morpholine-2,5-dione)-b-polyethylenimine (PEI-b-PLMD-b-PEI) and methoxy-poly(ethylene glycol)-b-poly(lactide-co-3(S)-methyl-morpholine-2,5-dione) (mPEG-b-PLMD) copolymers by a co-assembly method. Then the ZNF580 gene plasmid (pDNA) was encapsulated into the complex micelles. The hydrodynamic size and zeta potential of these complex micelles and micelles/pDNA complexes indicated that they were feasible for use in cellular uptake and gene transfection. As expected, the transfection efficiency and cytotoxicity of these micelles/pDNA complexes could be conveniently tuned by changing the mass ratio of mPEG-b-PLMD to PEI-b-PLMD-b-PEI (3/1, 2/2, 1/3 and 0/4) in the mixed mPEG/PEI shell. The transfection efficiency increased as the mass ratio of mPEG-b-PLMD/PEI-b-PLMD-b-PEI decreased from 3/1 to 0/4, while the cytotoxicity showed an opposite tendency. Moreover, ZNF580 protein expression determined by Western blot analysis and the migration of transfected endothelial cells (ECs) by wound healing assay were consistent with the result of transfection efficiency. All these results indicated that the co-assembled complex micelles could act as suitable gene carriers with tunable gene transfection efficiency and cytotoxicity, which should have great potential for the transfection of vascular ECs.

Effect of gold nanoparticle shapes for phototherapy and drug delivery

In this study, we compared three different hybrid gold nanoparticle shapes (spherical, rod and star) for photothermal therapy and the delivery of doxorubicin.

Utilising inorganic nanocarriers for gene delivery

The delivery of genetic materials into cells to elicit cellular response has been extensively studied by biomaterials scientists globally.

Redox-Triggered Gatekeeper-Enveloped Starlike Hollow Silica Nanoparticles for Intelligent Delivery Systems

The design and development of multifunctional carriers for drug delivery based on hollow nanoparticles (HNPs) have attracted intense interests. Ordinary spherical HNPs are demonstrated to be promising candidates. However, the application of HNPs with special morphologies has rarely been reported. HNPs with sharp horns are expected to own higher endocytosis efficiencies than spherical counterparts. In this work, novel starlike hollow silica nanoparticles (SHNPs) with different sizes are proposed as platforms for the fabrication of redox-triggered multifunctional systems for synergy of gene therapy and chemotherapy. The CD-PGEA gene vectors (consisting of β-CD cores and ethanolamine-functionalized poly(glycidyl methacrylate) (denoted BUCT-PGEA) arms) are introduced ingeniously onto the surfaces of SHNPs with plentiful disulfide bond-linked adamantine guests. The resulting supramolecular assemblies (SHNP-PGEAs) possess redox-responsive gatekeepers for loaded drugs in the cavities of SHNPs. Meanwhile, they also demonstrate excellent performances to deliver genes. The gene transfection efficiencies, controlled drug release behaviors, and synergistic antitumor effect of hollow silica-based carriers with different morphologies are investigated in detail. Compared with ordinary spherical HNP-based counterparts, SHNP-PGEA carriers with six sharp horns are proven to be superior gene vectors and possess better efficacy for cellular uptake and antitumor effects. The present multifunctional carriers based on SHNPs will have promising applications in drug/gene codelivery and cancer treatment.

Study of the nucleation and growth of antibiotic labeled Au NPs and blue luminescent Au8 quantum clusters for Hg(2+) ion sensing, cellular imaging and antibacterial applications

Herein, we report a detailed experimental study supported by DFT calculations to understand the mechanism behind the synthesis of cefradine (CFD--an antibiotic) labeled gold nanoparticles (Au NPs) by employing CFD as both a mild reducing and capping agent. The analysis of the effect of growth conditions reveals that a higher concentration of HAuCl4 results in the formation of an increasing fraction of anisotropic structures, higher temperature leads to the formation of quasi-spherical particles instead of anisotropic ones, and larger pH leads to the formation of much smaller particles. The cyclic voltammetry (CV) results show that when the pH of the reaction medium increases from 4 to 6, the reduction potential of CFD increases which leads to the synthesis of nanoparticles (in a pH 4 reaction) to quantum clusters (in a pH 6 reaction). The MALDI-TOF mass spectrometry results of supernatant of the pH 6 reaction indicate the formation of [Au8(CFD)2S6] QCs which show fluorescence at ca. 432 nm with a Stokes shift of ca. 95 nm. The blue luminescence from Au8 QCs was applied for sensing of Hg(2+) ions on the basis of an aggregation-induced fluorescence quenching mechanism and offers good selectivity and a high sensitivity with a limit of detection ca. 2 nM which is lower than the detection requirement of 10 nM by the U.S. EPA and 30 nM by WHO for drinking water. We have also applied the sensing probe to detect Hg(2+) ions in bacterial samples. Further, we have investigated the antibacterial property of as-synthesized Au NPs using MIC, growth curve and cell survival assay. The results show that Au NPs could reduce the cell survival very efficiently rather than the cell growth in comparison to the antibiotic itself. The scanning electron microscopy study shows the degradation and blebbing of the bacterial cell wall upon exposure with Au NPs which was further supported by fluorescence microscopy results. These Au NPs did not show reactive oxygen species generation. We believe that the bacterial cytotoxicity is due to the direct contact of the Au NPs with bacterial cells.

Retracted Article: Shape-specific silver nanoparticles prepared by microwave-assisted green synthesis using pomegranate juice for bacterial inactivation and removal

Green synthesis of different shaped-AgNPs & their antibacterial activity.