New low molecular weight polycation-based nanoparticles for effective codelivery of pDNA and drug

Hydroxyl-rich branched polycations for nucleic acid delivery

Recently, nucleic acid delivery has become an amazing route for the treatment of various malignant diseases, and polycationic vectors are attracting more and more attention among gene vectors. However, conventional polycationic vectors still face many obstacles in nucleic acid delivery, such as significant cytotoxicity, high protein absorption behavior, and unsatisfactory blood compatibility caused by a high positive charge density. To solve these problems, the fabrication of hydroxyl-rich branched polycationic vectors has been proposed. For the synthesis of hydroxyl-rich branched polycations, a one-pot method is considered as the preferred method due to its simple preparation process. In this review, typical one-pot methods for fabricating hydroxyl-rich polycations are presented. In particular, amine-epoxide ring-opening polymerization as a novel approach is mainly introduced. In addition, various therapeutic scenarios of hydroxyl-rich branched polycations via one-pot fabrication are also generalized. We believe that this review will motivate the optimized design of hydroxyl-rich branched polycations for potential nucleic acid delivery and their bio-applications.

Polymeric Delivery of Therapeutic Nucleic Acids

The advent of genome editing has transformed the therapeutic landscape for several debilitating diseases, and the clinical outlook for gene therapeutics has never been more promising. The therapeutic potential of nucleic acids has been limited by a reliance on engineered viral vectors for delivery. Chemically defined polymers can remediate technological, regulatory, and clinical challenges associated with viral modes of gene delivery. Because of their scalability, versatility, and exquisite tunability, polymers are ideal biomaterial platforms for delivering nucleic acid payloads efficiently while minimizing immune response and cellular toxicity. While polymeric gene delivery has progressed significantly in the past four decades, clinical translation of polymeric vehicles faces several formidable challenges. The aim of our Account is to illustrate diverse concepts in designing polymeric vectors towards meeting therapeutic goals of in vivo and ex vivo gene therapy. Here, we highlight several classes of polymers employed in gene delivery and summarize the recent work on understanding the contributions of chemical and architectural design parameters. We touch upon characterization methods used to visualize and understand events transpiring at the interfaces between polymer, nucleic acids, and the physiological environment. We conclude that interdisciplinary approaches and methodologies motivated by fundamental questions are key to designing high-performing polymeric vehicles for gene therapy.

A PEGylated photosensitizer-core pH-responsive polymeric nanocarrier for imaging-guided combination chemotherapy and photodynamic therapy

A novel chemo-photodynamic combined therapeutic self-assembly polymeric platform (MPEG-Hyd-Br₂-BODIPY) was constructed which can encapsulate DOX and exhibited an accelerated release rate with decreasing pH value which results in considerable time/dose-dependent cytotoxicity.

[12]aneN3-Based Gemini-Type Amphiphiles with Two-Photon Absorption Properties for Enhanced Nonviral Gene Delivery and Bioimaging

Although a plethora of nonviral gene vectors have been developed for potential gene therapy, imageable gemini surfactants with stimuli-responsiveness and high transfection efficiency are still scarce for gene delivery. Herein, three gemini amphiphiles (DEDPP-4/8/12) consisting of an aggregation-induced emission (AIE) central fluorophore: 5,6-diphenylpyrazine-2,3-diester (DEDPP), decorated with triazole-[12]aneN₃ as the hydrophilic moiety and alkyl chains of various lengths as the hydrophobic moiety, were designed and synthesized for trackable gene delivery via optical imaging. All three amphiphiles exhibited ultralow critical micelle concentrations (CMCs) (up to 3.40 × 10^-6 M), prominent two-photon absorption properties, and solvatochromic fluorescence. Gel electrophoresis assays demonstrated that the migration of plasmid DNA was completely retarded after condensation with these gemini amphiphiles at low concentrations (up to 10 μM). In addition, the ester bond in these amphiphiles may facilitate vector degradation and DNA release, in response to esterase and the acidic environment inside cells. Upon self-assembly with DOPE to form liposomes, DEDPP-8/DOPE achieved the best transfection efficiency in four cell lines, and the transfection efficiency of DEDPP-8/DOPE in HeLa cell lines was 23.5-fold higher than that of Lipo2000, which is unusually high for small organic molecule-based nonviral vectors. Furthermore, excellent transfection efficiency of DEDPP-8/DOPE was obtained in the presence of serum, and the red fluorescence protein (RFP) gene was successfully transfected in zebrafish embryos. Both one- and two-photon fluorescence imaging clearly demonstrated the delivery process of plasmid DNA. This study demonstrated that gemini-type amphiphiles composed of a two-photon fluorophore core conjugated with triazole-[12]aneN₃ via an ester bond afforded an unprecedentedly high transfection efficiency with excellent biocompatibility, which may provide new insights for the design and development of multifunctional nonviral gene vectors for imageable gene delivery.

pH-triggered intracellular release of doxorubicin by a poly(glycidyl methacrylate)-based double-shell magnetic nanocarrier

Two core-double-shell pH-sensitive nanocarriers were fabricated using Fe₃O₄ as magnetic core, poly(glycidyl methacrylate-PEG) and salep dialdehyde as the first and the second shell, and doxorubicin as the hydrophobic anticancer drug. Two nanocarriers were different in the drug loading steps. The interaction between the first and the second shell assumed to be pH-sensitive via acetal cross linkages. The structure of nanocarriers, organic shell loading, magnetic responsibility, morphology, size, dispersibility, and drug loading content were investigated by IR, NMR, TG, VSM, XRD, DLS, HRTEM and UV-Vis analyses. The long-term drug release profiles of both nanocarriers showed that the drug loading before cross-linking between the first and second shell led to a more pH-sensitive nanocarrier exhibiting higher control on DOX release. Cellular toxicity assay (MTT) showed that DOX-free nanocarrier is biocompatible having cell viability greater than 80% for HEK-293 and MCF-7 cell lines. Besides, high cytotoxic effect observed for drug-loaded nanocarrier on MCF-7 cancer cells. Cellular uptake analysis showed that the nanocarrier is able to transport DOX into the cytoplasm and perinuclear regions of MCF-7 cells. In vitro hemolysis and coagulation assays demonstrated high blood compatibility of nanocarrier. The results also suggested that low concentration of nanocarrier have a great potential as a contrast agent in magnetic resonance imaging (MRI).

The stilbene derivatives, nucleosides, and nucleosides modified by stilbene derivatives

In this short review, including 187 references, the issues of biological activity of stilbene derivatives and nucleosides and the biological and medicinal potential of fusion of these two classes are discussed. The stilbenes, especially the stilbenoids, and nucleosides are both biologically active. Hybrids formed from binding of these compounds have not yet been broadly studied. However, those that have been investigated exhibit desirable medicinal properties. The review is divided in such parts: I. Derivative of stilbene (biomedical investigations, biological activities in cells, enzymes and hazard), parts II. naturally occurred nucleoside and its derivatives: uridine, thymidine and 5-methyluridine, cytidine, adenosine, guanosine and part III. hybrid molecules- drugs and hybrid molecules- nucleoside - stilbene and its derivative.

Sequentially self-assembled polysaccharide-based nanocomplexes for combined chemotherapy and photodynamic therapy of breast cancer

Combination of chemotherapy and photodynamic therapy has emerged as a promising anticancer strategy. Polysaccharide-based nanoparticles are being intensively explored as drug carriers for different forms of combination therapy. In this study, novel multifunctional polysaccharide-based nanocomplexes were prepared from aldehyde-functionalized hyaluronic acid and hydroxyethyl chitosan via sequential self-assembly method. Stable nanocomplexes were obtained through both Schiff's base bond and electrostatic interactions. Chemotherapeutics doxorubicin and pro-photosensitizer 5-aminolevulinic acid were chemically conjugated onto the nanocomplexes via Schiff base linkage. Anti-HER2 antibody as targeting moiety was decorated onto the surface of nanocomplexes. The obtained near-spherical shaped nanocomplexes had an average size of 140 nm and a zeta potential of -24.6 mV, and displayed pH-responsive surface charge reversal and drug release. Active targeting strategy significantly enhanced the cellular uptake of nanocomplexes and combined anticancer efficiency of chemo-photodynamic dual therapy in breast cancer MCF-7 cells. These results suggested that the nanocomplexes had great potential for targeted combination therapy of breast cancer.

PEGylated mBPEI-rGO nanocomposites facilitate hepotocarcinoma treatment combining photothermal therapy and chemotherapy

Despite chemotherapy has been widely used for tumor therapy, the serious side effect is still a major challenge. Recently, two dimensional nanomaterial-based drug delivery systems have attracted wide concern due to their high drug loading and low side effect. In addition, some kinds of nanomaterials can directly act as a photosensitizer to induce cancer destruction. In this study, we developed a drug delivery system of mixture of high/low molecular weight branched polyethylenimine-polyethylene glycol-reduced graphene oxide (mBPEI-PEG-rGO) using reduced graphene oxide as matrix. A model drug of doxorubicin (DOX) was loaded on the nanocomposites with the efficiency of 81% and the release rate of more than 50% at acidic environment. In vitro experiments indicated that mBPEI-PEG-rGO-DOX with enhanced stability and biocompatibility efficiently delivered and released DOX into cells mainly through micropinocytosis and killed SMMC-7721 cells by inducing reactive oxygen species (ROS) and cell apoptosis. Furthermore, in vivo experiments indicated that the combination of intratumoral injection of mBPEI-PEG-rGO-DOX and local laser irradiation nearly ablated hepatocarcinoma. In conclusion, this new drug delivery system provided an alternative for combinational photothermal and chemotherapy against hepatocarcinoma.

A Self-Assembled Coumarin-Anchored Dendrimer for Efficient Gene Delivery and Light-Responsive Drug Delivery

The assembly of low molecular weight polymers into highly efficient and nontoxic nanostructures has broad applicability in gene delivery. In this study, we reported the assembly of coumarin-anchored low generation dendrimers in aqueous solution via hydrophobic interactions. The synthesized material showed significantly improved DNA binding and gene delivery, and minimal toxicity on the transfected cells. Moreover, the coumarin moieties in the assembled nanostructures endow the materials with light-responsive drug delivery behaviors. The coumarin substitutes in the assembled nanostructures were cross-linked with each other upon irradiation at 365 nm, and the cross-linked assemblies were degraded upon further irradiation at 254 nm. As a result, the drug-loaded nanoparticle showed a light-responsive drug release behavior and light-enhanced anticancer activity. The assembled nanoparticle also exhibited a complementary anticancer activity through the codelivery of 5-fluorouracil and a therapeutic gene encoding tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). This study provided a facile strategy to develop light-responsive polymers for the codelivery of therapeutic genes and anticancer drugs.

Synthesis and investigation of new cyclic molecules using the stilbene scaffold

A new approach to the synthesis of asymmetrical cyclic compounds using a stilbene scaffold has been developed. The use of boron trifluoride diethyl etherate as the catalyst, both with and without paraformaldehyde, allows us to obtain new substituted dioxanes, oxanes, cyclic compounds or dimer. The analysis of products was run using experimental and theoretical methods.

A new approach to the synthesis of asymmetrical cyclic compounds using a stilbene scaffold has been developed.

High-performance cationic polyrotaxanes terminated with polypeptides as promising nucleic acid delivery systems

A novel cationic polyrotaxane consisting of hydroxyl-rich polycationic units and degradable end-capping polypeptides was prepared for promising nucleic acid delivery.

"Bottom-Up" Construction of Hyperbranched Poly(prodrug-co-photosensitizer) Amphiphiles Unimolecular Micelles for Chemo-Photodynamic Dual Therapy

Despite the great advantages of chemo-photodynamic combination therapy, tedious synthesis steps and laborious purification procedures make the fabrication of chemo-photodynamic combined therapeutic platforms rather difficult. In this study, we develop a facile "bottom-up" strategy to fabricate hyperbranched poly(prodrug-co-photosensitizer) amphiphiles, h-P(CPTMA-co-BYMAI)-b-POEGMA (hPCBE), for chemo-photodynamic dual therapy. The easily prepared hPCBE possess a bottom-up-constructed hydrophobic core h-P(CPTMA-co-BYMAI) (hPCB) direct copolymerized from reduction-responsive CPT prodrug monomer (CPTMA) and boron dipyrromethene-based photosensitizer monomer (BYMAI), as well as a biocompatible shell polymerized from hydrophilic monomers. Because of the covalently interconnected core-shell structure, hPCBE exists as unimolecular micelles in aqueous solution and exhibits excellent structural stability under dilution condition. The hPCBE micelles can be effectively internalized by MCF-7 cells and release CPT triggered by the reductive milieu. In addition, photosensitizer moieties embedded in the hPCB core could generate singlet oxygen (¹O₂) effectively under irradiation, endowing hPCBE with the boosting of chemotherapeutic efficacy. As compared to the single chemotherapy of hyperbranched polyprodrug amphiphiles h-PCPTMA-b-POEGMA (hPCE) and photodynamic therapy of hyperbranched polyphotosensitizer amphiphiles h-PBYMAI-b-POEGMA (hPBE), hPCBE shows higher in vitro cytotoxicity. We expect that our approach will further boost research on the design of multifunctional drug delivery systems via the facile "bottom-up" strategy.

A Zwitterionic-Shielded Carrier with pH-Modulated Reversible Self-Assembly for Gene Transfection

Cationic vectors are ideal candidates for gene delivery thanks to their capability to carry large gene inserts and their scalable production. However, their cationic density gives rise to high cytotoxicity. We present the proper designed core-shell polyplexes made of either poly(ethylene imine) (PEI) or poly(2-dimethylamino ethyl methacrylate) (PDMAEMA) as the core and zwitterionic poly(acrylic acid)-block-poly(sulfobetaine methacrylate) (PAA-b-PSBMA) diblock copolymer as the shell. Gel retardation and ethidium bromide displacement assays were used to determine the PEI/DNA or PDMAEMA/DNA complexation. At neutral pH, the copolymer serves as a protective shell of the complex. As PSBMA is a nonfouling block, the shell reduced the cytotoxicity and enhanced the hemocompatibility (lower hemolysis activity, longer plasma clotting time) of the gene carriers. PAA segments in the copolymer impart pH sensitivity by allowing deshielding of the core in acidic solution. Therefore, the transfection efficiency of polyplexes at pH 6.5 was better than at pH 7.0, from β-galactosidase assay, and for all PAA-b-PSBMA tested. These results were supported by more favorable physicochemical properties in acidic solution (zeta potential, particle size, and interactions between the polymer and DNA). Thus, the results of this study offer a potential route to the development of efficient and nontoxic pH-sensitive gene carriers.

CAGW Peptide- and PEG-Modified Gene Carrier for Selective Gene Delivery and Promotion of Angiogenesis in HUVECs in Vivo

Gene therapy is a promising strategy for angiogenesis, but developing gene carriers with low cytotoxicity and high gene delivery efficiency in vivo is a key issue. In the present study, we synthesized the CAGW peptide- and poly(ethylene glycol) (PEG)-modified amphiphilic copolymers. CAGW peptide serves as a targeting ligand for endothelial cells (ECs). Different amounts of CAGW peptide were effectively conjugated to the amphiphilic copolymer via heterofunctional poly(ethylene glycol). These CAG- and PEG-modified copolymers could form nanoparticles (NPs) by self-assembly method and were used as gene carriers for the pEGFP-ZNF580 (pZNF580) plasmid. CAGW and PEG modification coordinately improved the hemocompatibility and cytocompatibility of NPs. The results of cellular uptake showed significantly enhanced internalization efficiency of pZNF580 after CAGW modification. Gene expression at mRNA and protein levels demonstrated that EC-targeted NPs possessed high gene delivery efficiency, especially the NPs with higher content of CAGW peptide (1.16 wt %). Furthermore, in vitro and in vivo vascularization assays also showed outstanding vascularization ability of human umbilical vein endothelial cells treated by the NP/pZNF580 complexes. This study demonstrates that the CAGW peptide-modified NP is a promising candidate for gene therapy in angiogenesis.

A Facile Strategy to Prepare Hyperbranched Hydroxyl-Rich Polycations for Effective Gene Therapy

For effective gene therapy, nonviral gene carriers with low toxicity and high transfection efficiency are of much importance. In this work, we developed a facile strategy to prepare hyperbranched hydroxyl-rich polycations (denoted by TE) by the one-pot method involving ring-opening reactions between two commonly used reagents, ethylenediamine (ED) with two amino groups and 1,3,5-triglycidyl isocyanurate (TGIC) with three epoxy groups. The hyperbranched TEs with different molecular weights were investigated on their DNA condensation ability, protein absorption property, biocompatibility, transfection efficiency, and in vivo cancer therapy and toxicity. TE exhibited low cytotoxicity and protein absorption property due to the plentiful hydroxyl groups. The optimal transfection efficiency of TE was significantly higher than that of the gold standard polycationic gene carrier branched polyethylenimine (PEI, 25 kDa). Furthermore, TE was applied for in vivo tumor inhibition by the delivery of antioncogene p53, which showed good antitumor efficiency with low adverse effects. The present work provides a new concept for the facile preparation of hyperbranched hydroxyl-rich polycationic carriers with good transfection performances.

PGMA-Based Cationic Nanoparticles with Polyhydric Iodine Units for Advanced Gene Vectors

It is crucial for successful gene delivery to develop safe, effective, and multifunctional polycations. Iodine-based small molecules are widely used as contrast agents for CT imaging. Herein, a series of star-like poly(glycidyl methacrylate) (PGMA)-based cationic vectors (II-PGEA/II) with abundant flanking polyhydric iodine units are prepared for multifunctional gene delivery systems. The proposed II-PGEA/II star vector is composed of one iohexol intermediate (II) core and five ethanolamine (EA) and II-difunctionalized PGMA arms. The amphipathic II-PGEA/II vectors readily self-assemble into well-defined cationic nanoparticles, where massive hydroxyl groups can establish a hydration shell to stabilize the nanoparticles. The II introduction improves cell viabilities of polycations. Moreover, by controlling the suitable amount of introduced II units, the resultant II-PGEA/II nanoparticles can produce fairly good transfection performances in different cell lines. Particularly, the II-PGEA/II nanoparticles induce much better in vitro CT imaging abilities in tumor cells than iohexol (one commonly used commercial CT contrast agent). The present design of amphipathic PGMA-based nanoparticles with CT contrast agents would provide useful information for the development of new multifunctional gene delivery systems.

Gold nanoparticles enhance anti-tumor effect of radiotherapy to hypoxic tumor

Purpose

Hypoxia can impair the therapeutic efficacy of radiotherapy (RT). Therefore, a new strategy is necessary for enhancing the response to RT. In this study, we investigated whether the combination of nanoparticles and RT is effective in eliminating the radioresistance of hypoxic tumors.

Materials and Methods

Gold nanoparticles (GNPs) consisting of a silica core with a gold shell were used. CT26 colon cancer mouse model was developed to study whether the combination of RT and GNPs reduced hypoxia-induced radioresistance. Hypoxia inducible factor-1α (HIF-1α) was used as a hypoxia marker. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were conducted to evaluate cell death.

Results

Hypoxic tumor cells had an impaired response to RT. GNPs combined with RT enhanced anti-tumor effect in hypoxic tumor compared with RT alone. The combination of GNPs and RT decreased tumor cell viability compare to RT alone in vitro. Under hypoxia, tumors treated with GNPs + RT showed a higher response than that shown by tumors treated with RT alone. When a reactive oxygen species (ROS) scavenger was added, the enhanced antitumor effect of GNPs + RT was diminished.

Conclusion

In the present study, hypoxic tumors treated with GNPs + RT showed favorable responses, which might be attributable to the ROS production induced by GNPs + RT. Taken together, GNPs combined with RT seems to be potential modality for enhancing the response to RT in hypoxic tumors.

Well-defined reducible cationic nanogels based on functionalized low-molecular-weight PGMA for effective pDNA and siRNA delivery

Nucleic acid-based gene therapy is a promising treatment option to cure numerous intractable diseases. For non-viral gene carriers, low-molecular-weight polymeric vectors generally demonstrate poor transfection performance, but benefit their final removals from the body. Recently, it was reported that aminated poly(glycidyl methacrylate) (PGMA) is one potential gene vector. Based on ethylenediamine (ED)-functionalized low-molecular-weight PGMA (denoted by PGED), a flexible strategy was herein proposed to design new well-defined reducible cationic nanogels (denoted by PGED-NGs) with friendly crosslinking reagents for highly efficient nucleic acid delivery. α-Lipoic acid (LA), one natural antioxidant in human body, was readily introduced into ED-functionalized PGMA and crosslinked to produce cationic PGED-NGs with plentiful reducible lipoyl groups. PGED-NGs could effectively complex plasmid DNA (pDNA) and short interfering RNA (siRNA). Compared with pristine PGED, PGED-NGs exhibited much better performance of pDNA transfection. PGED-NGs also could efficiently transport MALAT1 siRNA (siR-M) into hepatoma cells and significantly suppressed the cancer cell proliferation and migration. The present work indicated that reducible cationic nanogels involving LA crosslinking reagents are one kind of competitive candidates for high-performance nucleic acid delivery systems.

STATEMENT OF SIGNIFICANCE

Recently, the design of new types of high-performance nanoparticles is of great significance in delivering therapeutics. Nucleic acid-based therapy is a promising treatment option to cure numerous intractable diseases. A facile and straightforward strategy to fabricate safe nucleic acid delivery nanovectors is highly desirable. In this work, based on ethylenediamine-functionalized low-molecular-weight poly(glycidyl methacrylate), a flexible strategy was proposed to design new well-defined reducible cationic nanogels (denoted by PGED-NGs) with α-Lipoic acid, one friendly crosslinking reagent, for highly efficient nucleic acid delivery. Such PGED-NGs possess plentiful reducible lipoyl groups, effectively encapsulated pDNA and siRNA and exhibited excellent abilities of nucleic acid delivery. The present work indicated that reducible cationic nanogels involving α-lipoic acid crosslinking reagents are one kind of competitive candidates for high-performance nucleic acid delivery systems.

Multifunctional pDNA-Conjugated Polycationic Au Nanorod-Coated Fe3 O4 Hierarchical Nanocomposites for Trimodal Imaging and Combined Photothermal/Gene Therapy

It is very desirable to design multifunctional nanocomposites for theranostic applications via flexible strategies. The synthesis of one new multifunctional polycationic Au nanorod (NR)-coated Fe3 O4 nanosphere (NS) hierarchical nanocomposite (Au@pDM/Fe3 O4 ) based on the ternary assemblies of negatively charged Fe3 O4 cores (Fe3 O4 -PDA), polycation-modified Au nanorods (Au NR-pDM), and polycations is proposed. For such nanocomposites, the combined near-infrared absorbance properties of Fe3 O4 -PDA and Au NR-pDM are applied to photoacoustic imaging and photothermal therapy. Besides, Fe3 O4 and Au NR components allow the nanocomposites to serve as MRI and CT contrast agents. The prepared positively charged Au@pDM/Fe3 O4 also can complex plasmid DNA into pDNA/Au@pDM/Fe3 O4 and efficiently mediated gene therapy. The multifunctional applications of pDNA/Au@pDM/Fe3 O4 nanocomposites in trimodal imaging and combined photothermal/gene therapy are demonstrated using a xenografted rat glioma nude mouse model. The present study demonstrates that the proper assembly of different inorganic nanoparticles and polycations is an effective strategy to construct new multifunctional theranostic systems.

One-step Conjugation of Glycyrrhetinic Acid to Cationic Polymers for High-performance Gene Delivery to Cultured Liver Cell

Gene therapies represent a promising therapeutic route for liver cancers, but major challenges remain in the design of safe and efficient gene-targeting delivery systems. For example, cationic polymers show good transfection efficiency as gene carriers, but are hindered by cytotoxicity and non-specific targeting. Here we report a versatile method of one-step conjugation of glycyrrhetinic acid (GA) to reduce cytotoxicity and improve the cultured liver cell -targeting capability of cationic polymers. We have explored a series of cationic polymer derivatives by coupling different ratios of GA to polypropylenimine (PPI) dendrimer. These new gene carriers (GA-PPI dendrimer) were systematically characterized by UV-vis,(1)H NMR titration, electron microscopy, zeta potential, dynamic light-scattering, gel electrophoresis, confocal microscopy and flow cytometry. We demonstrate that GA-PPI dendrimers can efficiently load and protect pDNA, via formation of nanostructured GA-PPI/pDNA polyplexes. With optimal GA substitution degree (6.31%), GA-PPI dendrimers deliver higher liver cell transfection efficiency (43.5% vs 22.3%) and lower cytotoxicity (94.3% vs 62.5%, cell viability) than the commercial bench-mark DNA carrier bPEI (25 kDa) with cultured liver model cells (HepG2). There results suggest that our new GA-PPI dendrimer are a promising candidate gene carrier for targeted liver cancer therapy.

Functionalized PGMA nanoparticles with aggregation-induced emission characteristics for gene delivery systems

AIE fluorogen conjugated cationic nanoparticles with excellent bioimaging abilities and stable morphologies were designed for multifunctional gene delivery systems.

A pH-sensitive prodrug micelle self-assembled from multi-doxorubicin-tailed polyethylene glycol for cancer therapy

A novel tetra-doxorubicin-tailed polyethylene glycol via benzoic-imine bond linkage was synthesized and self-assembled to a pH-sensitive prodrug micelle.

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.

Host-Guest Interaction-Based Self-Engineering of Nano-Sized Vesicles for Co-Delivery of Genes and Anticancer Drugs

On the basis of host-guest interactions, this study reported a kind of linear-hyperbranched supramolecular amphiphile and its assembled vesicles for the combined achievement of drug encapsulation and DNA delivery. Amine-attached β-cyclodextrin-centered hyperbranched polyglycerol and linear adamantane-terminated octadecane were arranged to spontaneously interlink together and then self-assemble into nanoscale vesicles. As the model of a hydrophilic agent, DOX·HCl was demonstrated to be readily loaded into the hollow cavity of the vesicles. The drug release pattern could be controlled by adjusting the environmental acidity, favoring the intracellularly fast drug liberation in response to the cellular lysosomal microenvironment. The nanovesicles displayed superior serum-tolerant transgene ability and significantly lower cytotoxicity compared to those of PEI25K, the gold standard of gene delivery vectors. The drug-loaded nanovesicle can co-deliver DNA payloads into cells and allow the preferable accumulation of two payloads in nuclei. The drug encapsulation was found to have little influence on the transfection. This co-delivery vehicle presents a good example of rational design of cationic supramolecular vesicles for stimulus-responsive drug/DNA transport.

MicroRNA Replacing Oncogenic Klf4 and c-Myc for Generating iPS Cells via Cationized Pleurotus eryngii Polysaccharide-based Nanotransfection

Induced pluripotent stem cells (iPSCs), resulting from the forced expression of cocktails out of transcription factors, such as Oct4, Sox2, Klf4, and c-Myc (OSKM), has shown tremendous potential in regenerative medicine. Although rapid progress has been made recently in the generation of iPSCs, the safety and efficiency remain key issues for further application. In this work, microRNA 302-367 was employed to substitute the oncogenic Klf4 and c-Myc in the OSKM combination as a safer strategy for successful iPSCs generation. The negatively charged plasmid mixture (encoding Oct4, Sox2, miR302-367) and the positively charged cationized Pleurotus eryngii polysaccharide (CPEPS) self-assembled into nanosized particles, named as CPEPS-OS-miR nanoparticles, which were applied to human umbilical cord mesenchymal stem cells for iPSCs generation after characterization of the physicochemical properties. The CPEPS-OS-miR nanoparticles possessed spherical shape, ultrasmall particle size, and positive surface charge. Importantly, the combination of plasmids Oct4, Sox2, and miR302-367 could not only minimize genetic modification but also show a more than 50 times higher reprogramming efficiency (0.044%) than any other single or possible double combinations of these factors (Oct4, Sox2, miR302-367). Altogether, the current study offers a simple, safe, and effective self-assembly approach for generating clinically applicable iPSCs.

Independent effect of polymeric nanoparticle zeta potential/surface charge, on their cytotoxicity and affinity to cells

OBJECTIVES

Up to now, little research has been focussed on discovering how zeta potential independently affects polymeric nanoparticle (NP) cytotoxicity.

METHODS

Polymeric nanoparticles of gradient zeta potential ranging from -30 mv to +40 mv were fabricated using the same poly-3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBHHx) biopolymer. Interaction forces between nanoparticles and cells were measured by atomic force microscopy (AFM). Cytotoxicity of the nanoparticles to cells was investigated by using MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay.

RESULTS

Four kinds of nanoparticle with similar sizes and gradient zeta potentials, were fabricated. Those with positive surface charges were found to be more toxic than those with negative surface charges. Positively charged nanoparticles or nanoparticles with higher 'like' charges, offered higher interaction force with cells.

CONCLUSION

This work proposes a novel approach for investigating interaction between NPs and cells, and discloses the importance of controlling zeta potential in developing NPs-based formulations in the future.

Acid-Labile Poly(glycidyl methacrylate)-Based Star Gene Vectors

It was recently reported that ethanolamine-functionalized poly(glycidyl methacrylate) (PGEA) possesses great potential applications in gene therapy due to its good biocompatibility and high transfection efficiency. Importing responsivity into PGEA vectors would further improve their performances. Herein, a series of responsive star-shaped vectors, acetaled β-cyclodextrin-PGEAs (A-CD-PGEAs) consisting of a β-CD core and five PGEA arms linked by acid-labile acetal groups, were proposed and characterized as therapeutic pDNA vectors. The A-CD-PGEAs owned abundant hydroxyl groups to shield extra positive charges of A-CD-PGEAs/pDNA complexes, and the star structure could decrease charge density. The incorporation of acetal linkers endowed A-CD-PGEAs with pH responsivity and degradation. In weakly acidic endosome, the broken acetal linkers resulted in decomposition of A-CD-PGEAs and morphological transformation of A-CD-PGEAs/pDNA complexes, lowering cytotoxicity and accelerating release of pDNA. In comparison with control CD-PGEAs without acetal linkers, A-CD-PGEAs exhibited significantly better transfection performances.

Surface modification and endothelialization of biomaterials as potential scaffolds for vascular tissue engineering applications

This review highlights the recent developments of surface modification and endothelialization of biomaterials in vascular tissue engineering applications.

Multi-arm carriers composed of an antioxidant lignin core and poly(glycidyl methacrylate-co-poly(ethylene glycol)methacrylate) derivative arms for highly efficient gene delivery

A lignin-based copolymer with good biocompability was successfully prepared via atom transfer radical polymerization (ATRP) for efficient gene delivery.

POSS-based hybrid cationic copolymers with low aggregation potential for efficient gene delivery

This work describes the synthesis and application of POSS-based copolymers with low aggregation potential for efficient gene delivery.