Mussel Adhesion‐Inspired Reverse Transfection Platform Enhances Osteogenic Differentiation and Bone Formation of Human Adipose‐Derived Stem Cells

Using small interfering RNA (siRNA) to regulate gene expression is an emerging strategy for stem cell manipulation to improve stem cell therapy. However, conventional methods of siRNA delivery into stem cells based on solution‐mediated transfection are limited due to low transfection efficiency and insufficient duration of cell‐siRNA contact during lengthy culturing protocols. To overcome these limitations, a bio‐inspired polymer‐mediated reverse transfection system is developed consisting of implantable poly(lactic‐co‐glycolic acid) (PLGA) scaffolds functionalized with siRNA‐lipidoid nanoparticle (sLNP) complexes via polydopamine (pDA) coating. Immobilized sLNP complexes are stably maintained without any loss of siRNA on the pDA‐coated scaffolds for 2 weeks, likely due to the formation of strong covalent bonds between amine groups of sLNP and catechol group of pDA. siRNA reverse transfection with the pDA‐sLNP‐PLGA system does not exhibit cytotoxicity and induces efficient silencing of an osteogenesis inhibitor gene in human adipose‐derived stem cells (hADSCs), resulting in enhanced osteogenic differentiation of hADSCs. Finally, hADSCs osteogenically committed on the pDA‐sLNP‐PLGA scaffolds enhanced bone formation in a mouse model of critical‐sized bone defect. Therefore, the bio‐inspired reverse transfection system can provide an all‐in‐one platform for genetic modification, differentiation, and transplantation of stem cells, simultaneously enabling both stem cell manipulation and tissue engineering.     

SiRNA drug delivery by biodegradable polymeric nanoparticles

RNA interference (RNAi) is an emerging technology in which the introduction of double-stranded RNA (dsRNA) into a diverse range of organisms and cell types causes degradation of the complementary mRNA. It offers a broad spectrum of applications in both biological and medical research. Small interference RNA (siRNA) was recently explored for its therapeutical potential. However, the drug delivery of siRNA oligos is very novel and is in great need of future research. To this end, a biodegradable poly(D,L-lactide-co-glycolide) (PLGA) nanoparticle drug carrier system was prepared to load siRNA oligos with desired physicochemical properties. The nanoparticles were characterized by scanning electron microscopy and laser diffraction particle sizer. The delivery of siRNA into the targeted 293T cells was observed using fluorescent-labeled double-stranded Cy3-oligos. The model siRNA oligos, si-GFP-RNA, were also successfully loaded into PLGA nanoparticles and delivered in 293T cells. The gene silencing effect and the inhibition of GFP expression were investigated using fluorescent microscopy. Both positive and negative controls were used to compare with the new siRNA nanoparticle delivery system. It was found that nanoparticles offered both effective delivery of siRNA and prominent GFP gene silencing effect. Compared to conventional carrier systems, the new biodegradable polymeric nanoparticle system may also offer improved formulation stability, which is practically beneficial and may be used in the future clinical studies of siRNA therapeutics.     

Modified nanoprecipitation method to fabricate DNA-loaded PLGA nanoparticles

Objective: The objective of this study was to formulate DNA-loaded poly(d,l-lactide-co-glycotide) (PLGA) nanoparticles by a modified nanoprecipitation method. Methods: DNA-loaded PLGA nanoparticles were prepared by the modified nanoprecipitation method and the double emulsion/solvent evaporation method. The characterizations of DNA-loaded nanoparticles such as entrapment efficiency, morphology, particle size, zeta potential, structural integrity of the loaded DNA, and stability of the loaded DNA in PLGA nanoparticles against DNase I, in vitro release, cell viability and in vitro transfection capability were investigated. Results: The resulted PLGA nanoparticles by the modified nanoprecipitation method had uniform spherical shape, narrow size distribution with average particles size near 200 nm, negative zeta potential of ?12.6 mV at pH 7.4, and a sustained-release property in vitro. Plasmid DNA could be efficiently encapsulated into PLGA nanoparticles (>95%) without affecting its intact conformation using this modified nanoprecipitation method, which was superior to the double emulsion/solvent evaporation method. The PLGA nanoparticles were much safer to A549 cell compared to commercial Lipofectamine 2000 and could successfully transfer plasmid-enhanced green fluorescent protein into A549 cells. Conclusion: In conclusion, the modified nanoprecipitation method could be applied as an efficient way to fabricate DNA-loaded PLGA nanoparticles instead of the conventional double emulsion/solvent evaporation method.     

Targeted Delivery of siRNA‐Generating DNA Nanocassettes Using Multifunctional Nanoparticles

Molecular therapy using a small interfering RNA (siRNA) has shown promise in the development of novel therapeutics. Various formulations have been used for in vivo delivery of siRNAs. However, the stability of short double‐stranded RNA molecules in the blood and efficiency of siRNA delivery into target organs or tissues following systemic administration have been the major issues that limit applications of siRNA in human patients. In this study, multifunctional siRNA delivery nanoparticles are developed that combine imaging capability of nanoparticles with urokinase plasminogen activator receptor‐targeted delivery of siRNA expressing DNA nanocassettes. This theranostic nanoparticle platform consists of a nanoparticle conjugated with targeting ligands and double‐stranded DNA nanocassettes containing a U6 promoter and a shRNA gene for in vivo siRNA expression. Targeted delivery and gene silencing efficiency of firefly luciferase siRNA nanogenerators are demonstrated in tumor cells and in animal tumor models. Delivery of survivin siRNA expressing nanocassettes into tumor cells induces apoptotic cell death and sensitizes cells to chemotherapy drugs. The ability of expression of siRNAs from multiple nanocassettes conjugated to a single nanoparticle following receptor‐mediated internalization should enhance the therapeutic effect of the siRNA‐mediated cancer therapy.     

N-Alkyl-PEI-functionalized iron oxide nanoclusters for efficient siRNA delivery

Small-interfering RNA (siRNA) is an emerging class of therapeutics, which works by regulating the expression of a specific gene involved in disease progression. Despite the promises, effective transport of siRNA with minimal side effects remains a challenge. In this study, a nonviral nanoparticle gene carrier is developed and its efficiency for siRNA delivery and transfection is validated at both in vitro and in vivo levels. Such a nanocarrier, abbreviated as Alkyl-PEI2k-IO, was constructed with a core of iron oxide nanoparticles (IOs) and a shell of alkylated polyethyleneimine of 2000 Da [corrected] molecualr weight (Alkyl-PEI2k). It is found to be able to bind with siRNA, resulting in well-dispersed nanoparticles with a controlled clustering structure and narrow size distribution. Electrophoresis studies show that the Alkyl-PEI2k-IOs could retard siRNA completely at N:P ratios (i.e., PEI nitrogen to nucleic acid phosphate) above 10, protect siRNA from enzymatic degradation in serum, and release complexed siRNA efficiently in the presence of polyanionic heparin. The knockdown efficiency of the siRNA-loaded nanocarriers is assessed with 4T1 cells stably expressing luciferase (fluc-4T1) and further, with a fluc-4T1 xenograft model. Significant down-regulation of luciferase is observed, and unlike high-molecular-weight analogues, the Alkyl-PEI2k-coated IOs show good biocompatibility. In conclusion, Alkyl-PEI2k-IOs demonstrate highly efficient delivery of siRNA and an innocuous toxic profile, making it a potential carrier for gene therapy.     

Synthesis and Assembly of Click‐Nucleic‐Acid‐Containing PEG–PLGA Nanoparticles for DNA Delivery

Co‐delivery of both chemotherapy drugs and siRNA from a single delivery vehicle can have a significant impact on cancer therapy due to the potential for overcoming issues such as drug resistance. However, the inherent chemical differences between charged nucleic acids and hydrophobic drugs have hindered entrapment of both components within a single carrier. While poly(ethylene glycol)‐block‐poly(lactic‐co‐glycolic acid) (PEG–PLGA) copolymers have been used successfully for targeted delivery of chemotherapy drugs, loading of DNA or RNA has been poor. It is demonstrated that significant amounts of DNA can be encapsulated within PLGA‐containing nanoparticles through the use of a new synthetic DNA analog, click nucleic acids (CNAs). First, triblock copolymers of PEG‐CNA‐PLGA are synthesized and then formulated into polymer nanoparticles from oil‐in‐water emulsions. The CNA‐containing particles show high encapsulation of DNA complementary to the CNA sequence, whereas PEG‐PLGA alone shows minimal DNA loading, and non‐complementary DNA strands do not get encapsulated within the PEG‐CNA‐PLGA nanoparticles. Furthermore, the dye pyrene can be successfully co‐loaded with DNA and lastly, a complex, larger DNA sequence that contains an overhang complementary to the CNA can also be encapsulated, demonstrating the potential utility of the CNA‐containing particles as carriers for chemotherapy agents and gene silencers.     

A Poly(Propyleneimine) Dendrimer‐Based Polyplex‐System for Single‐Chain Antibody‐Mediated Targeted Delivery and Cellular Uptake of SiRNA

Therapeutics based on small interfering RNAs (siRNAs) offer a great potential to treat so far incurable diseases or metastatic cancer. However, the broad application of siRNAs using various nonviral carrier systems is hampered by unspecific toxic side effects, poor pharmacokinetics due to unwanted delivery of siRNA‐loaded nanoparticles into nontarget organs, or rapid renal excretion. In order to overcome these obstacles, several targeting strategies using chemically linked antibodies and ligands have emerged. This study reports a new modular polyplex carrier system for targeted delivery of siRNA, which is based on transfection‐disabled maltose‐modified poly(propyleneimine)‐dendrimers (mal‐PPI) bioconjugated to single chain fragment variables (scFvs). To achieve targeted delivery into tumor cells expressing the epidermal growth factor receptor variant III (EGFRvIII), monobiotinylated anti‐EGFRvIII scFv fused to a Propionibacterium shermanii transcarboxylase‐derived biotinylation acceptor (P‐BAP) is bioconjugated to mal‐PPI through a novel coupling strategy solely based on biotin–neutravidin bridging. In contrast to polyplexes containing an unspecific control scFv‐P‐BAP, the generated EGFRvIII‐specific polyplexes are able to exclusively deliver siRNA to tumor cells and tumors by receptor‐mediated endocytosis. These results suggest that receptor‐mediated uptake of otherwise noninternalized mal‐PPI‐based polyplexes is a promising avenue to improve siRNA therapy of cancer, and introduce a novel strategy for modular bioconjugation of protein ligands to nanoparticles.     

载紫杉醇聚乳酸-羟基乙酸纳米粒的体外释药研究

以生物可降解材料聚乳酸-羟基乙酸(PLGA)为载体制备了载紫杉醇纳米粒,重点考察了纳米粒的体外释放特性.采用乳化-溶剂挥发法制备了载紫杉醇PLGA纳米粒,其平均粒径为200nm,载药量为21%,包封率为89.44%;体外释药符合Higuchi方程:Q=3.8796t1/2+30.4649(r=0.9397),同时载紫杉醇纳米粒具有一定的缓释作用.     

Immune Cell‐Mediated Biodegradable Theranostic Nanoparticles for Melanoma Targeting and Drug Delivery

Although tremendous efforts have been made on targeted drug delivery systems, current therapy outcomes still suffer from low circulating time and limited targeting efficiency. The integration of cell‐mediated drug delivery and theranostic nanomedicine can potentially improve cancer management in both therapeutic and diagnostic applications. By taking advantage of innate immune cell's ability to target tumor cells, the authors develop a novel drug delivery system by using macrophages as both nanoparticle (NP) carriers and navigators to achieve cancer‐specific drug delivery. Theranostic NPs are fabricated from a unique polymer, biodegradable photoluminescent poly (lactic acid) (BPLP‐PLA), which possesses strong fluorescence, biodegradability, and cytocompatibility. In order to minimize the toxicity of cancer drugs to immune cells and other healthy cells, an anti‐BRAF V600E mutant melanoma specific drug (PLX4032) is loaded into BPLP‐PLA nanoparticles. Muramyl tripeptide is also conjugated onto the nanoparticles to improve the nanoparticle loading efficiency. The resulting nanoparticles are internalized within macrophages, which are tracked via the intrinsic fluorescence of BPLP‐PLA. Macrophages carrying nanoparticles deliver drugs to melanoma cells via cell–cell binding. Pharmacological studies also indicate that the PLX4032 loaded nanoparticles effectively kill melanoma cells. The “self‐powered” immune cell‐mediated drug delivery system demonstrates a potentially significant advancement in targeted theranostic cancer nanotechnologies.     

Formulation and characterisation of poly(lactic‐co‐glycolic acid) encapsulated clove oil nanoparticles for dental applications

This study investigated synthesis and characterisation of Nano‐PLGA (poly(lactic‐co‐glycolic acid))/CO (clove‐oil) nanoparticles. The delivery of drug‐loaded nanoparticles to demineralised dentin substrates and their morphological association with a two‐step etch‐and‐rinse adhesive system was studied. The effect of Nano‐PLGA/CO pretreatment on micro‐tensile bond strength of resin‐dentin bonding was scrutinised. This study employed CO‐containing PLGA nanoparticles as a delivery vehicle for sustainable drug release inside dentinal‐tubules for potential dental applications. Emulsion evaporation resulted in uniformly distributed negatively‐charged Nano‐PLGA/Blank and Nano‐PLGA/CO nanoparticles. Scanning electron microscopy/ transmission electron microscopy revealed even spherical nanoparticles with smooth texture. High CO‐loading and encapsulation were achieved. Moreover, controlled CO‐release was evidenced after 15 days, in‐vitro and ex‐vivo. Nanoparticles exhibited low initial toxicity towards human mesenchymal stem cells with excellent antibacterial properties. Nanoparticles penetration inside dentinal‐tubules indicated a close correlation with resin‐tags. Nano‐PLGA/CO pretreatment indicated reduction in short‐term bond strength of resin‐dentin specimens. Nano‐PLGA/CO as model drug‐loaded nanoparticles showed excellent metric and antibacterial properties, low toxicity and sustained CO release. However, the loading of nanoparticles with CO up to ∼10 mg (Nano‐PLGA/CO:10) did not adversely affect short‐term bond strength values. This drug‐delivery strategy could be further expanded to deliver other pulp‐sedative agents and medications with other dental relevance.Inspec keywords: nanoparticles, dentistry, encapsulation, filled polymers, nanofabrication, nanocomposites, nanomedicine, biomedical materials, drug delivery systems, adhesives, tensile strength, biomechanics, resins, proteins, molecular biophysics, biochemistry, emulsions, evaporation, scanning electron microscopy, transmission electron microscopy, texture, cellular biophysics, antibacterial activity, bonds (chemical)Other keywords: poly(lactic‐co‐glycolic acid) encapsulated clove oil nanoparticles, dental applications, drug‐loaded nanoparticle delivery, demineralised dentin substrates, morphological association, two‐step etch‐and‐rinse adhesive system, simulated pulpal pressure, nanoPLGA‐CO pretreatment, microtensile bond strength, resin‐dentin bonded specimens, CO‐containing PLGA nanoparticles, delivery vehicle, sustainable drug release, dentinal‐tubules, potential dental applications, emulsion evaporation, uniformly‐distributed negatively‐charged nanoPLGA‐blank, scanning electron microscopy‐transmission electron microscopy, spherical nanoparticles, smooth texture, high CO‐loading, controlled CO‐release, human mesenchymal stem cells, antibacterial properties, antibiofilm properties, deep nanoparticle penetration, resin‐tags, short‐term bond strength, resin‐dentin specimens, metric properties, antibacterial properties, sustained CO release, pulp‐sedative agents, time 15 d     

Efficient gene delivery to mesenchymal stem cells by an ethylenediamine-modified polysaccharide from mulberry leaves

This study investigates the use of a natural polysaccharide isolated from mulberry leaves as a nonviral gene vector. Ethylenediamine is chemically grafted to the backbone of a polysaccharide from mulberry leaves (MPS) to acquire nucleic acid binding affinity. A particle-size observation indicates that the cationic mulberry leaf polysaccharide (CMPS) can efficiently combine with plasmid transforming growth factor β1 (TGF-β1) to form nanoscaled particles. In addition, the electrophoresis assay indicates a retarded plasmid migration when the CMPS/pTGF-β1 weight ratio is increased to 30:1. The in vitro cell transfection experiment is performed based on bone marrow mesenchymal stem cells (MSCs) derived from rat femurs and tibias, and the findings reveal that the complex with a CMPS/pTGF-β1 weight ratio of 50:1 exhibits the highest cell transfection effect, which is significantly higher than that of branched poly(ethyleneimine) (PEI) (25 kDa; p = 0.001, Student's t-test) and slightly higher than Lipofectamine 2000. Moreover, the cytotoxicity assay also demonstrates that all of these tested complexes and the plasmid TGF-β1 are nontoxic to mesenchymal stem cells (MSCs). The results of the living cell imaging confirm that more of the CMPS/plasmid TGF-β1 nanoparticles can be taken up and at a faster rate by the MSCs than by the positive control Lipofectamine 2000; these data are consistent with the transfection efficiency data. Together, these results suggest that the CMPS/pTGF-β1 nanoparticle can potentially be developed into a promising alternative for the transfer of therapeutic genes into cells.     

Amorphous Silica Nanoparticles Promote Monocyte Adhesion to Human Endothelial Cells: Size‐Dependent Effect

There is evidence that nanoparticles can induce endothelial dysfunction. Here, the effect of monodisperse amorphous silica nanoparticles (SiO₂‐NPs) of different diameters on endothelial cells function is examined. Human endothelial cell line (EA.hy926) or primary human pulmonary artery endothelial cells (hPAEC) are seeded in inserts introduced or not above triple cell co‐cultures (pneumocytes, macrophages, and mast cells). Endothelial cells are incubated with SiO₂‐NPs at non‐cytotoxic concentrations for 12 h. A significant increase (up to 2‐fold) in human monocytes adhesion to endothelial cells is observed for 18 and 54 nm particles. Exposure to SiO₂‐NPs induces protein expression of adhesion molecules (ICAM‐1 and VCAM‐1) as well as significant up‐regulation in mRNA expression of ICAM‐1 in both endothelial cell types. Experiments performed with fluorescent‐labelled monodisperse amorphous SiO₂‐NPs of similar size evidence nanoparticle uptake into the cytoplasm of endothelial cells. It is concluded that exposure of human endothelial cells to amorphous silica nanoparticles enhances their adhesive properties. This process is modified by the size of the nanoparticle and the presence of other co‐cultured cells.     

Nanostructured medical device coatings based on self-assembled poly(lactic-co-glycolic acid) nanoparticles

Here we present a new method for providing nanostructured drug-loaded polymer films which enable control of film surface morphology and delivery of therapeutic agents. Silicon wafers were employed as models for implanted biomaterials and poly(lactic-co-glycolic acid) (PLGA) nanoparticles were assembled onto the silicon surface by electrostatic interaction. Monolayers of the PLGA particles were deposited onto the silicon surface upon incubation in an aqueous particle suspension. Particle density and surface coverage of the silicon wafers were varied by altering particle concentration, incubation time in nanoparticle suspension and ionic strength of the suspension. Dye loaded nanoparticles were prepared and assembled to silicon surface to form nanoparticle films. Fluorescence intensity measurements showed diffusion-controlled release of the dye over two weeks and atomic force microscopy (AFM) analysis revealed that these particles remained attached to the surface during the incubation time. This work suggests that coating implants with PLGA nanoparticles is a versatile technique which allows drug release from the implant surface and modulation of surface morphology.     

Biodegradable Nanocapsules as siRNA Carriers for Mutant K‐Ras Gene Silencing of Human Pancreatic Carcinoma Cells

The application of small interfering RNA (siRNA)‐based RNA interference (RNAi) for cancer gene therapy has attracted great attention. Gene therapy is a promising strategy for cancer treatment because it is relatively non‐invasive and has a higher therapeutic specificity than chemotherapy. However, without the use of safe and efficient carriers, siRNAs cannot effectively penetrate the cell membranes and RNAi is impeded. In this work, cationic poly(lactic acid) (CPLA)‐based degradable nanocapsules (NCs) are utilized as novel carriers of siRNA for effective gene silencing of pancreatic cancer cells. These CPLA‐NCs can readily form nanoplexes with K‐Ras siRNA and over 90% transfection efficiency is achieved using the nanoplexes. Cell viability studies show that the nanoparticles are highly biocompatible and non‐toxic, indicating that CPLA‐NC is a promising potential candidate for gene therapy in a clinical setting.     

Molecularly self-assembled nucleic acid nanoparticles for targeted in vivo siRNA delivery

Nanoparticles are used for delivering therapeutics into cells. However, size, shape, surface chemistry and the presentation of targeting ligands on the surface of nanoparticles can affect circulation half-life and biodistribution, cell-specific internalization, excretion, toxicity and efficacy. A variety of materials have been explored for delivering small interfering RNAs (siRNAs)--a therapeutic agent that suppresses the expression of targeted genes. However, conventional delivery nanoparticles such as liposomes and polymeric systems are heterogeneous in size, composition and surface chemistry, and this can lead to suboptimal performance, a lack of tissue specificity and potential toxicity. Here, we show that self-assembled DNA tetrahedral nanoparticles with a well-defined size can deliver siRNAs into cells and silence target genes in tumours. Monodisperse nanoparticles are prepared through the self-assembly of complementary DNA strands. Because the DNA strands are easily programmable, the size of the nanoparticles and the spatial orientation and density of cancer-targeting ligands (such as peptides and folate) on the nanoparticle surface can be controlled precisely. We show that at least three folate molecules per nanoparticle are required for optimal delivery of the siRNAs into cells and, gene silencing occurs only when the ligands are in the appropriate spatial orientation. In vivo, these nanoparticles showed a longer blood circulation time (t(1/2) ≈ 24.2 min) than the parent siRNA (t(1/2) ≈ 6 min).     

Iron‐Oxide‐Based Nanovector for Tumor Targeted siRNA Delivery in an Orthotopic Hepatocellular Carcinoma Xenograft Mouse Model

Hepatocellular carcinoma (HCC) is one of the deadliest cancers worldwide. Small interfering RNA (siRNA) holds promise as a new class of therapeutics for HCC, as it can achieve sequence‐specific gene knockdown with low cytotoxicity. However, the main challenge in the clinical application of siRNA lies in the lack of effective delivery approaches that need to be highly specific and thus incur low or no systemic toxicity. Here, a nonviral nanoparticle‐based gene carrier is presented that can specifically deliver siRNA to HCC. The nanovector (NP‐siRNA‐GPC3 Ab) is made of an iron oxide core coated with chitosan‐polyethylene glycol (PEG) grafted polyethyleneimine copolymer, which is further functionalized with siRNA and conjugated with a monoclonal antibody (Ab) against human glypican‐3 (GPC3) receptor highly expressed in HCC. A rat RH7777 HCC cell line that coexpresses human GPC3 and firefly luciferase (Luc) is established to evaluate the nanovector. The nanoparticle‐mediated delivery of siRNA against Luc effectively suppresses Luc expression in vitro without notable cytotoxicity. Significantly, NP‐siLuc‐GPC3 Ab administered intravenously in an orthotopic model of HCC is able to specifically bound to tumor and induce remarkable inhibition of Luc expression. The findings demonstrate the potential of using this nanovector for targeted delivery of therapeutic siRNA to HCC.     

Constrained Nanoparticles Deliver siRNA and sgRNA to T Cells In Vivo without Targeting Ligands

T cells help regulate immunity, which makes them an important target for RNA therapies. While nanoparticles carrying RNA have been directed to T cells in vivo using protein‐ and aptamer‐based targeting ligands, systemic delivery to T cells without targeting ligands remains challenging. Given that T cells endocytose lipoprotein particles and enveloped viruses, two natural systems with structures that can be similar to lipid nanoparticles (LNPs), it is hypothesized that LNPs devoid of targeting ligands can deliver RNA to T cells in vivo. To test this hypothesis, the delivery of siRNA to 9 cell types in vivo by 168 nanoparticles using a novel siGFP‐based barcoding system and bioinformatics is quantified. It is found that nanomaterials containing conformationally constrained lipids form stable LNPs, herein named constrained lipid nanoparticles (cLNPs). cLNPs deliver siRNA and sgRNA to T cells at doses as low as 0.5 mg kg^?1 and, unlike previously reported LNPs, do not preferentially target hepatocytes. Delivery occurs via a chemical composition‐dependent, size‐independent mechanism. These data suggest that the degree to which lipids are constrained alters nanoparticle targeting, and also suggest that natural lipid trafficking pathways can promote T cell delivery, offering an alternative to active targeting approaches.     

Effective Gene Delivery into Human Stem Cells with a Cell‐Targeting Peptide‐Modified Bioreducible Polymer

Stem cells are poorly permissive to non‐viral gene transfection reagents. In this study, we explored the possibility of improving gene delivery into human embryonic (hESC) and mesenchymal (hMSC) stem cells by synergizing the activity of a cell‐binding ligand with a polymer that releases nucleic acids in a cytoplasm‐responsive manner. A 29 amino acid long peptide, RVG, targeting the nicotinic acetylcholine receptor (nAchR) was identified to bind both hMSC and H9‐derived hESC. Conjugating RVG to a redox‐sensitive biodegradable dendrimer‐type arginine‐grafted polymer (PAM‐ABP) enabled nanoparticle formation with plasmid DNA without altering the environment‐sensitive DNA release property and favorable toxicity profile of the parent polymer. Importantly, RVG‐PAM‐ABP quantitatively enhanced transfection into both hMSC and hESC compared to commercial transfection reagents like Lipofectamine 2000 and Fugene. ～60% and 50% of hMSC and hESC were respectively transfected, and at increased levels on a per cell basis, without affecting pluripotency marker expression. RVG‐PAM‐ABP is thus a novel bioreducible, biocompatible, non‐toxic, synthetic gene delivery system for nAchR‐expressing stem cells. Our data also demonstrates that a cell‐binding ligand like RVG can cooperate with a gene delivery system like PAM‐ABP to enable transfection of poorly‐permissive cells.     

Sialic acid‐conjugated PLGA nanoparticles enhance the protective effect of lycopene in chemotherapeutic drug‐induced kidney injury

Lycopene (LYC) is known to protect cells from oxidative damage caused by free radicals in human tissues. In the present study, the authors designed a LYC‐loaded sialic acid (SA)‐conjugated poly(D,L‐lactide‐co‐glycolide) (PLGA) nanoparticle (LYC‐NP) to enhance the therapeutic efficacy of LYC in acute kidney injury. The characteristics of the LYC‐NPs were defined according to particle size, morphology, and in vitro drug release. The LYC‐NPs exhibited a controlled release of LYC over 48 h. Confocal laser scanning microscopy clearly highlighted the targeting potential of SA. Enhanced green fluorescence was observed for the LYC‐NPs in H₂ O₂ ‐treated human umbilical vein endothelial cells, indicating enhanced internalisation of NPs. The LYC‐NPs showed significantly greater cell viability than H₂ O₂ ‐treated cells. In addition, the LYC‐NPs remarkably reduced proinflammatory cytokine levels, attributable mainly to the increased cellular internalisation of the SA‐based carrier delivery system. Furthermore, protein levels of caspase‐3 and ‐9 were significantly down‐regulated after treatment with the LYC‐NPs. Overall, they have demonstrated that SA‐conjugated PLGA‐NPs containing LYC could be used to treat kidney injury.Inspec keywords: fluorescence, biomedical materials, biological tissues, cellular biophysics, drugs, proteins, molecular biophysics, injuries, drug delivery systems, kidney, nanomedicine, biochemistry, optical microscopy, nanoparticles, nanofabrication, cancer, toxicology, blood vessels, particle sizeOther keywords: sialic acid‐conjugated PLGA nanoparticles, chemotherapeutic drug‐induced kidney injury, LYC‐NP, LYC‐loaded sialic acid‐conjugated poly(D,L‐lactide‐co‐glycolide) nanoparticle, SA‐conjugated PLGA‐NP, protective effect, lycopene, human tissues, particle size, in vitro drug release, confocal laser scanning microscopy, green fluorescence, human umbilical vein endothelial cells, cell viability, proinflammatory cytokine levels, cellular internalisation, SA‐based carrier delivery system, time 48.0 hour     

Programmed Nanoparticle‐Loaded Nanoparticles for Deep‐Penetrating 3D Cancer Therapy

Tumors are 3D, composed of cellular agglomerations and blood vessels. Therapies involving nanoparticles utilize specific accumulations due to the leaky vascular structures. However, systemically injected nanoparticles are mostly uptaken by cells located on the surfaces of cancer tissues, lacking deep penetration into the core cancer regions. Herein, an unprecedented strategy, described as injecting “nanoparticle‐loaded nanoparticles” to address the long‐lasting problem is reported for effective surface‐to‐core drug delivery in entire 3D tumors. The “nanoparticle‐loaded nanoparticle” is a silica nanoparticle (≈150 nm) with well‐developed, interconnected channels (diameter of ≈30 nm), in which small gold nanoparticles (AuNPs) (≈15 nm) with programmable DNA are located. The nanoparticle (AuNPs)‐loaded nanoparticles (silica): (1) can accumulate in tumors through leaky vascular structures by protecting the inner therapeutic AuNPs during blood circulation, and then (2) allow diffusion of the AuNPs for penetration into the entire surface‐to‐core tumor tissues, and finally (3) release a drug triggered by cancer‐characteristic pH gradients. The hierarchical “nanoparticle‐loaded nanoparticle” can be a rational design for cancer therapies because the outer large nanoparticles are effective in blood circulation and in protection of the therapeutic nanoparticles inside, allowing the loaded small nanoparticles to penetrate deeply into 3D tumors with anticancer drugs.