scholarly journals Encapsulation of Large-Size Plasmids in PLGA Nanoparticles for Gene Editing: Comparison of Three Different Synthesis Methods

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2723
Author(s):  
Tresa López-Royo ◽  
Víctor Sebastián ◽  
Laura Moreno-Martínez ◽  
Laura Uson ◽  
Cristina Yus ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Gene Editing ◽  
Structural Integrity ◽  
Viral Vector ◽  
Release Kinetics ◽  
Double Emulsion ◽  
Plga Nanoparticles ◽  
Synthesis Methods ◽  
Experimental Conditions ◽  
Large Size

The development of new gene-editing technologies has fostered the need for efficient and safe vectors capable of encapsulating large nucleic acids. In this work we evaluate the synthesis of large-size plasmid-loaded PLGA nanoparticles by double emulsion (considering batch ultrasound and microfluidics-assisted methodologies) and magnetic stirring-based nanoprecipitation synthesis methods. For this purpose, we characterized the nanoparticles and compared the results between the different synthesis processes in terms of encapsulation efficiency, morphology, particle size, polydispersity, zeta potential and structural integrity of loaded pDNA. Our results demonstrate particular sensibility of large pDNA for shear and mechanical stress degradation during double emulsion, the nanoprecipitation method being the only one that preserved plasmid integrity. However, plasmid-loaded PLGA nanoparticles synthesized by nanoprecipitation did not show cell expression in vitro, possibly due to the slow release profile observed in our experimental conditions. Strong electrostatic interactions between the large plasmid and the cationic PLGA used for this synthesis may underlie this release kinetics. Overall, none of the methods evaluated satisfied all the requirements for an efficient non-viral vector when applied to large-size plasmid encapsulation. Further optimization or alternative synthesis methods are thus in current need to adapt PLGA nanoparticles as delivery vectors for gene editing therapeutic technologies.

Microfluidic Synthesis of Rifampicin Loaded PLGA Nanoparticles and the Effect of Formulation on their Physical and Antibacterial Properties

2020 ◽  
Vol 73 (3) ◽  
pp. 151
Author(s):  
Thomas G. Meikle ◽  
Calum J. Drummond ◽  
Charlotte E. Conn
Keyword(s):  
Oleic Acid ◽  
Release Kinetics ◽  
Antibacterial Properties ◽  
Fold Increase ◽  
Plga Nanoparticles ◽  
Spectrophotometric Analysis ◽  
Poly Vinyl Alcohol ◽  
Synthesis Methods ◽  
Loading Efficiency ◽  
Model Drug

The encapsulation of drugs in nanoparticles serves as an effective way to modify pharmacokinetics and therapeutic efficacy. Nanoparticles comprised of poly(d,l-lactide-co-glycolide) (PLGA) are well suited for this purpose; they are accessible using multiple synthesis methods, are highly biocompatible and biodegradable, and possess desirable drug release properties. In the present study, we have explored the effects of various formulation parameters on the physical properties of PLGA nanoparticles synthesised using a microfluidic assisted nanoprecipitation method and loaded with a model drug. PLGA nanoparticles, with diameters ranging from 165–364nm, were produced using three alternate stabilisers; poly(vinyl alcohol) (PVA), d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), and didodecyldimethylammonium bromide (DMAB). Three additional formulations used PVA in addition to 20wt-% 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), 1,2-di-O-octadecenyl-3-trimethylammonium propane (DOTMA), and oleic acid. Spectrophotometric analysis demonstrated that the use of PVA increased the loading efficiency over that of TPGS and DMAB formulations, while the inclusion of oleic acid in the PVA formulation resulted in a further 3-fold increase in loading efficiency. Invitro release studies demonstrate that the inclusion of lipid additives significantly alters release kinetics; release was most rapid and complete in the formulation containing oleic acid, while the addition of DOTAP and DOTMA significantly reduced release rates. Finally, the antimicrobial activity of each formulation was tested against Staphylococcus aureus and Bacillus cereus, with minimum inhibitory concentrations nearing or exceeding that of free rifampicin.

PLGA Nanoparticles for Anti Tuberculosis Drug Delivery

2012 ◽  
Vol 584 ◽  
pp. 465-469 ◽  
Author(s):  
S. Malathi ◽  
S. Balasubramanian
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Release Kinetics ◽  
Drug Loading ◽  
Double Emulsion ◽  
Plga Nanoparticles ◽  
Release Mechanism ◽  
Sustained Drug Release ◽  
Drug Release Kinetics ◽  
Evaporation Technique

Nanoparticles-based drug delivery systems have considerable potential for the treatment of tuberculosis (TB). A series of PLGA polymers with different molar feed ratios (P2:87/13, P3:83/17, P5:63/37, P6:76/24, P9:53/47) were synthesized by direct melt poly condensation method. The resulting biodegradable polymers were characterized by FTIR and 1H NMR spectroscopy. The preparation of the drug (Pyrazinamide (PZA)) encapsulated PLGA polymers were carried out by double emulsion – solvent evaporation technique. The drug loaded PLGA-NPs were analyzed by UV-visible spectroscopy and scanning electron microscopy. The drug loading efficiency and drug release kinetics varies in the following order: P9>P5>P6>P3>P2. Among the formulations, PP9 showed a uniform as well as sustained drug release. The drug release kinetics has been evaluated by Zero-order, First order, Higuchi and Koresmeyer- Peppas models and the release mechanism has also been investigated

scholarly journals A Controlled Release Codelivery System of MSCs Encapsulated in Dextran/Gelatin Hydrogel with TGF-β3-Loaded Nanoparticles for Nucleus Pulposus Regeneration

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Yibo Gan ◽  
Sukai Li ◽  
Pei Li ◽  
Yuan Xu ◽  
Liyuan Wang ◽  
...  
Keyword(s):  
Controlled Release ◽  
Nucleus Pulposus ◽  
Release Kinetics ◽  
Double Emulsion ◽  
Plga Nanoparticles ◽  
Gelatin Hydrogel ◽  
Engineering Strategy ◽  
A Cell

Mesenchymal stem cell- (MSC-) based therapy is regarded as a potential tissue engineering strategy to achieve nucleus pulposus (NP) regeneration for the treatment of intervertebral disc degeneration (IDD). However, it is still a challenge to induce MSC differentiation in NP-like cells when MSCs are implanted into the NP. The purpose of this study was to construct poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles as carriers for TGF-β3 controlled release and establish a codelivery system of a dextran/gelatin hydrogel with the nanoparticles for long-term processing of discogenesis differentiation. TGF-β3-loaded PLGA nanoparticles were prepared by the double-emulsion solvent evaporation method and seeded uniformly into the hydrogel. Morphological observations, an assessment of the release kinetics of TGF-β3, a cytotoxic assay, a cell proliferation test, a biochemical content assay, qRT-PCR, and immunohistological analyses of the codelivery system were conducted in the study. The results showed that the TGF-β3-loaded nanoparticles could release TGF-β3 gradually. The codelivery system exhibited favorable cytocompatibility, and the TGF-β3 that was released could induce MSCs to NP-like cells while promoting ECM-related biosynthesis. These results suggest this codelivery system may be employed as a promising carrier for discogenesis of MSCsin situ.

scholarly journals Dual drug-loaded biodegradable Janus particles for simultaneous co-delivery of hydrophobic and hydrophilic compounds

2019 ◽  
Vol 244 (14) ◽  
pp. 1162-1177 ◽  
Author(s):  
Jennifer S Winkler ◽  
Mayur Barai ◽  
Maria S Tomassone
Keyword(s):  
Release Kinetics ◽  
Drug Loading ◽  
Double Emulsion ◽  
Janus Particles ◽  
Synthesis Methods ◽  
Emulsion Method ◽  
Hydrophilic Drugs ◽  
Hydrophilic Drug ◽  
Vis Spectroscopy ◽  
Hydrophilic Compounds

Bicompartmental Janus particles have many advantages in drug delivery, including co-delivery of two compounds with varying solubilities, differential release kinetics, and two surfaces available for targeting ligands. We present a novel strategy using the double emulsion method for the coencapsulation and staggered release of a hydrophobic and hydrophilic drug from anisotropic PLGA/PCL Janus particles, as well as a UV detection method to measure the release of two different compounds from Janus particles. Curcumin and quercetin were chosen as the model hydrophobic compounds for drug loading studies, while acetaminophen (APAP) and naproxen were chosen as the model hydrophilic–hydrophobic drug pair for encapsulation methods and drug loading. Also, a similar double emulsion method was also applied for PLGA/Preicrol® Janus particles containing Doxorubicin and Curcumin. Hydrophobic drugs were encapsulated by the single O/W emulsion technique. Hydrophilic compounds required special modifications due to their poor oil solubility and tendency to escape to the outer aqueous phase during the emulsification and solvent evaporation steps. In total, three different strategies for incorporating hydrophilic drugs were employed: (1) O/W emulsion with partially water miscible solvent, (2) O/W emulsion with co-solvent (i.e. acetone, methanol, ethanol), or (3) W/O/W double emulsion. The encapsulation efficiencies and drug loading percentages were measured using UV/Vis spectroscopy and compared for the different synthesis methods. It was found that the double emulsion method resulted in the highest encapsulation efficiency and drug loading of the hydrophilic drug.

scholarly journals Evaluating the potential of novel genetic approaches for the treatment of Duchenne muscular dystrophy

2021 ◽  
Author(s):  
Vratko Himič ◽  
Kay E. Davies
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Structural Integrity ◽  
Viral Vector ◽  
Exon Skipping ◽  
Dystrophin Gene ◽  
Pharmacological Treatments ◽  
Genetic Sequencing ◽  
Reading Frame ◽  
Target Effects

AbstractDuchenne muscular dystrophy (DMD) is an X-linked progressive muscle-wasting disorder that is caused by a lack of functional dystrophin, a cytoplasmic protein necessary for the structural integrity of muscle. As variants in the dystrophin gene lead to a disruption of the reading frame, pharmacological treatments have only limited efficacy; there is currently no effective therapy and consequently, a significant unmet clinical need for DMD. Recently, novel genetic approaches have shown real promise in treating DMD, with advancements in the efficacy and tropism of exon skipping and surrogate gene therapy. CRISPR-Cas9 has the potential to be a ‘one-hit’ curative treatment in the coming decade. The current limitations of gene editing, such as off-target effects and immunogenicity, are in fact partly constraints of the delivery method itself, and thus research focus has shifted to improving the viral vector. In order to halt the loss of ambulation, early diagnosis and treatment will be pivotal. In an era where genetic sequencing is increasingly utilised in the clinic, genetic therapies will play a progressively central role in DMD therapy. This review delineates the relative merits of cutting-edge genetic approaches, as well as the challenges that still need to be overcome before they become clinically viable.

scholarly journals Selective growth of Ti3+/TiO2/CNT and Ti3+/TiO2/C nanocomposite for enhanced visible-light utilization to degrade organic pollutants by lowering TiO2-bandgap

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeasmin Akter ◽  
Md. Abu Hanif ◽  
Md. Akherul Islam ◽  
Kamal Prasad Sapkota ◽  
Jae Ryang Hahn
Keyword(s):  
Visible Light ◽  
Structural Integrity ◽  
Carbon Layer ◽  
Wide Bandgap ◽  
Blue Dye ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Excellent Photocatalytic Activity ◽  
Convenient Route ◽  
Walled Carbon Nanotubes

AbstractA convenient route was developed for the selective preparation of two stable nanocomposites, Ti3+/TiO2/CNT (labeled as TTOC-1 and TTOC-3) and Ti3+/TiO2/carbon layer (labeled as TTOC-2), from the same precursor by varying the amount of single-walled carbon nanotubes used in the synthesis. TiO2 is an effective photocatalyst; however, its wide bandgap limits its usefulness to the UV region. As a solution to this problem, our prepared nanocomposites exhibit a small bandgap and wide visible-light (VL) absorption because of the introduction of carbonaceous species and Ti3+ vacancies. The photocatalytic efficiency of the nanocomposites was examined via the degradation of methylene blue dye under VL. Excellent photocatalytic activity of 83%, 98%, and 93% was observed for TTOC-1, TTOC-2, and TTOC-3 nanocomposites within 25 min. In addition, the photocatalytic degradation efficiency of TTOC-2 toward methyl orange, phenol, rhodamine B, and congo red was 28%, 69%, 71%, and 91%, respectively, under similar experimental conditions after 25 min. Higher reusability and structural integrity of the as-synthesized photocatalyst were confirmed within five consecutive runs by photocatalytic test and X-ray diffraction analysis, respectively. The resulting nanocomposites provide new insights into the development of VL-active and stable photocatalysts with high efficiencies.

scholarly journals Sustained VEGF delivery via PLGA nanoparticles promotes vascular growth

2010 ◽  
Vol 298 (6) ◽  
pp. H1959-H1965 ◽  
Author(s):  
Justin S. Golub ◽  
Young-tae Kim ◽  
Craig L. Duvall ◽  
Ravi V. Bellamkonda ◽  
Divya Gupta ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Blood Vessel ◽  
Femoral Artery ◽  
Release Kinetics ◽  
Aortic Ring ◽  
Plga Nanoparticles ◽  
Cardiovascular Medicine ◽  
Vessel Growth ◽  
Vessel Volume

Technologies to increase tissue vascularity are critically important to the fields of tissue engineering and cardiovascular medicine. Currently, limited technologies exist to encourage angiogenesis and arteriogenesis in a controlled manner. In the present study, we describe an injectable controlled release system consisting of VEGF encapsulated in poly(lactic- co-glycolic acid) (PLGA) nanoparticles (NPs). The majority of VEGF was released gradually over 2–4 days from the NPs as determined by an ELISA release kinetics experiment. An in vitro aortic ring bioassay was used to verify the bioactivity of VEGF-NPs compared with empty NPs and no treatment. A mouse femoral artery ischemia model was then used to measure revascularization in VEGF-NP-treated limbs compared with limbs treated with naked VEGF and saline. 129/Sv mice were anesthetized with isoflurane, and a region of the common femoral artery and vein was ligated and excised. Mice were then injected with VEGF-NPs, naked VEGF, or saline. After 4 days, three-dimensional microcomputed tomography angiography was used to quantify vessel growth and morphology. Mice that received VEGF-NP treatment showed a significant increase in total vessel volume and vessel connectivity compared with 5 μg VEGF, 2.5 μg VEGF, and saline treatment (all P < 0.001). When the yield of the fabrication process was taken into account, VEGF-NPs were over an order of magnitude more potent than naked VEGF in increasing blood vessel volume. Differences between the VEGF-NP group and all other groups were even greater when only small-sized vessels under 300 μm diameter were analyzed. In conclusion, sustained VEGF delivery via PLGA NPs shows promise for encouraging blood vessel growth in tissue engineering and cardiovascular medicine applications.

scholarly journals Encapsulation in Polymeric Nanoparticles Enhances the Enzymatic Stability and the Permeability of the GLP-1 Analog, Liraglutide, Across a Culture Model of Intestinal Permeability

Pharmaceutics ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 599 ◽  
Author(s):  
Ruba Ismail ◽  
Alexandra Bocsik ◽  
Gábor Katona ◽  
Ilona Gróf ◽  
Mária A. Deli ◽  
...  
Keyword(s):  
Cell Model ◽  
Morphological Changes ◽  
Polymeric Nanoparticles ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Intestinal Barrier ◽  
Double Emulsion ◽  
Intercellular Junctions ◽  
Enzyme Degradation

The potential of poly (lactic-co-glycolic acid) nanoparticles (PLGA NPs) to overcome the intestinal barrier that limits oral liraglutide delivery was evaluated. Liraglutide-loaded PLGA NPs were prepared by the double emulsion solvent evaporation method. In vitro release kinetics and enzymatic degradation studies were conducted, mimicking the gastrointestinal environment. The permeability of liraglutide solution, liraglutide-loaded PLGA NPs, and liraglutide in the presence of the absorption enhancer PN159 peptide was tested on the Caco-2 cell model. Liraglutide release from PLGA NPs showed a biphasic release pattern with a burst effect of less than 15%. The PLGA nanosystem protected the encapsulated liraglutide from the conditions simulating the gastric environment. The permeability of liraglutide encapsulated in PLGA NPs was 1.5-fold higher (24 × 10−6 cm/s) across Caco-2 cells as compared to liraglutide solution. PLGA NPs were as effective at elevating liraglutide penetration as the tight junction-opening PN159 peptide. No morphological changes were seen in the intercellular junctions of Caco-2 cells after treatment with liraglutide-PLGA NPs, confirming the lack of a paracellular component in the transport mechanism. PLGA NPs, by protecting liraglutide from enzyme degradation and enhancing its permeability across intestinal epithelium, hold great potential as carriers for oral GLP-1 analog delivery.

Global Assessment System for Structural Safety in Large Size Storage Tanks

2004 ◽  
Author(s):  
Shinichi Kaita ◽  
Toshikazu Shibasaki ◽  
Takayasu Tahara
Keyword(s):  
Crude Oil ◽  
Global Assessment ◽  
Structural Integrity ◽  
Storage System ◽  
Assessment System ◽  
Structural Safety ◽  
Risk Level ◽  
Storage Tanks ◽  
Large Size

Considering long term stable supply of oil fuel, the world largest long-term storage system of crude oil has been installed in Japan. In order to ensure safety of large size above ground storage tanks, global assessment system for structural integrity of tank considering risk level and shut down inspection interval has been developed on Risk Based Inspection, RBI and Fitness-For-Service, FFS for storage tanks of crude oil for national security reserve.

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