scholarly journals The Impact of Nylon-3 Copolymer Composition on the Efficiency of siRNA Delivery to Glioblastoma Cells

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 986 ◽  
Author(s):  
Natascha Hartl ◽  
Friederike Adams ◽  
Gabriella Costabile ◽  
Lorenz Isert ◽  
Markus Döblinger ◽  
...  

Glioblastoma multiforme is a devastating disease that has attracted enormous attention due to poor prognosis and high recurrence. Small interfering RNA (siRNA) in principle offers a promising therapeutic approach by the downregulation of disease-related genes via RNA interference. For efficient siRNA delivery to target sites, cationic polymers are often used in preclinical studies for the protection of siRNA and complex formation based on electrostatic interactions. In an effort to develop biocompatible and efficient nanocarriers with a translational outlook for optimal gene silencing at reduced toxicity, we synthesized two sets of nylon-3 copolymers with variable cationic content (DM or NM monomer) and hydrophobic subunits (CP monomer) and evaluated their suitability for in vitro siRNA delivery into glioblastoma cells. DM0.4/CP0.6 and NM0.4/CP0.6 polymers with similar subunit ratios were synthesized to compare the effect of different cationic subunits. Additionally, we utilized NM0.2/CP0.8 polymers to evaluate the impact of the different hydrophobic content in the polymer chain. The siRNA condensation ability and polymer–siRNA complex stability was evaluated by unmodified and modified SYBR gold assays, respectively. Further physicochemical characteristics, e.g., particle size and surface charge, were evaluated by dynamic light scattering and laser Doppler anemometry, whereas a relatively new method for polyplex size distribution analysis—tunable resistive pulse sensing—was additionally developed and compared to DLS measurements. Transfection efficiencies, the route of cell internalization, and protein knockdown abilities in glioblastoma cells were investigated by flow cytometry. Furthermore, cellular tolerability was evaluated by MTT and LDH assays. All the polymers efficiently condensed siRNA at N/P ratios of three, whereas polymers with NM cationic subunits demonstrated smaller particle size and lower polyplex stability. Furthermore, NM0.2/CP0.8 polyplexes with the highest hydrophobic content displayed significantly higher cellular internalization in comparison to more cationic formulations and successful knockdown capabilities. Detailed investigations of the cellular uptake route demonstrated that these polyplexes mainly follow clathrin-mediated endocytotic uptake mechanisms, implying high interaction capacity with cellular membranes. Taken together with conducive toxicity profiles, highly hydrophobic nylon-3 polymers provide an appropriate siRNA delivery agent for the potential treatment of glioblastoma.

2022 ◽  
Vol 8 ◽  
Author(s):  
Ao Li ◽  
Aixia Zhu ◽  
Di Kong ◽  
Chunwei Wang ◽  
Shiping Liu ◽  
...  

For improving solubility and bioaccessibility of phytosterols (PS), phytosterol nanoparticles (PNPs) were prepared by emulsification–evaporation combined high-pressure homogenization method. The organic phase was formed with the dissolved PS and soybean lecithin (SL) in anhydrous ethanol, then mixed with soy protein isolate (SPI) solution, and homogenized into nanoparticles, followed by the evaporation of ethanol. The optimum fabrication conditions were determined as PS (1%, w/v): SL of 1:4, SPI content of 0.75% (w/v), and ethanol volume of 16 ml. PNPs were characterized to have average particle size 93.35 nm, polydispersity index (PDI) 0.179, zeta potential −29.3 mV, and encapsulation efficiency (EE) 97.3%. The impact of temperature, pH, and ionic strength on the stability of fabricated PNPs was determined. After 3-h in vitro digestion, the bioaccessibility of PS in nanoparticles reached 70.8%, significantly higher than the 18.2% of raw PS. Upon freeze-drying, the particle size of PNPs increased to 199.1 nm, resulting in a bimodal distribution. The solubility of PS in water could reach up to 2.122 mg/ml, ~155 times higher than that of raw PS. Therefore, this study contributes to the development of functional PS-food ingredients.


2020 ◽  
Vol 16 ◽  
Author(s):  
Erdal Eroğlu ◽  
Hüseyin Saygın Portakal ◽  
Ayşenur Pamukçu

Background: Despite great hopes for small interfering RNA (siRNA)-based gene therapies, restrictions, including the presence of nucleases, reticuloendothelial system and undesired electrostatic interactions between nucleic acids and the cell membrane, limit the success of these approaches. In the last few decades, non-viral nucleic acid delivery vectors in nano size with high biocompatibility, low toxicity and proton sponge effect have emerged as magic bullets to overcome these drawbacks. Objective: This study aimed to develop poly(2-hydroxyethyl methacrylate) (pHEMA)-chitosan nanoparticles (PCNp), and to transfect green fluorescent protein (GFP)-silencing siRNA (GsiR) in vitro. Method: First, PCNp displaying core-shell structure was synthesized and thereafter GsiR was encapsulated into the core of PCNp. The synthesized PCNp with/without GsiR were characterized using ultraviolet-visible (UV-vis)-spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, thermal decomposition, atomic force microscopy (AFM), scanning electron microscopy (SEM), zeta potential and dynamic light scattering (DLS) measurements. Encapsulation of siRNA into the pHEMA core coated with chitosan shell was demonstrated using fluorescence and FTIR spectroscopy. Results: The surface charge of PCNSs and PCNSs-GsiR were found to be +39.5 and +40.2, respectively. In DLS analysis, an insignificant shift in the Z-average diameter of PCNp was observed from 109 nm to 133 nm using encapsulation of GsiR. In comparison to other studied nanomaterials and a commercial transfection reagent, our findings suggest a promising GFP-silencing effect of 45%. Conclusion: To our knowledge, we have obtained comparable silencing activity with the other studied equivalents despite using the lowest concentration of siRNA in existing literature.


Gut ◽  
2017 ◽  
Vol 67 (10) ◽  
pp. 1813-1823 ◽  
Author(s):  
Romana R Gerner ◽  
Victoria Klepsch ◽  
Sophie Macheiner ◽  
Kathrin Arnhard ◽  
Timon E Adolph ◽  
...  

ObjectiveNicotinamide phosphoribosyltransferase (NAMPT, also referred to as pre-B cell colony-enhancing factor or visfatin) is critically required for the maintenance of cellular nicotinamide adenine dinucleotide (NAD) supply catalysing the rate-limiting step of the NAD salvage pathway. NAMPT is strongly upregulated in inflammation including IBD and counteracts an increased cellular NAD turnover mediated by NAD-depleting enzymes. These constitute an important mechanistic link between inflammatory, metabolic and transcriptional pathways and NAD metabolism.DesignWe investigated the impact of NAMPT inhibition by the small-molecule inhibitor FK866 in the dextran sulfate sodium (DSS) model of colitis and the azoxymethane/DSS model of colitis-associated cancer. The impact of NAD depletion on differentiation of mouse and human primary monocytes/macrophages was studied in vitro. Finally, we tested the efficacy of FK866 compared with dexamethasone and infliximab in lamina propria mononuclear cells (LPMNC) isolated from patients with IBD.ResultsFK866 ameliorated DSS-induced colitis and suppressed inflammation-associated tumorigenesis in mice. FK866 potently inhibited NAMPT activity as demonstrated by reduced mucosal NAD, resulting in reduced abundances and activities of NAD-dependent enzymes including PARP1, Sirt6 and CD38, reduced nuclear factor kappa B activation, and decreased cellular infiltration by inflammatory monocytes, macrophages and activated T cells. Remarkably, FK866 effectively supressed cytokine release from LPMNCs of patients with IBD. As FK866 was also effective in Rag1−⁄− mice, we mechanistically linked FK866 treatment with altered monocyte/macrophage biology and skewed macrophage polarisation by reducing CD86, CD38, MHC-II and interleukin (IL)-6 and promoting CD206, Egr2 and IL-10.ConclusionOur data emphasise the importance of NAD immunometabolism for mucosal immunity and highlight FK866-mediated NAMPT blockade as a promising therapeutic approach in acute intestinal inflammation.


Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 69
Author(s):  
Zuzanna Rzepka ◽  
Jakub Rok ◽  
Mateusz Maszczyk ◽  
Artur Beberok ◽  
Justyna Magdalena Hermanowicz ◽  
...  

The most important biological function of vitamin B12 is to accomplish DNA synthesis, which is necessary for cell division. Cobalamin deficiency may be especially acute for rapidly dividing cells, such as glioblastoma cells. Therefore, cobalamin antagonists offer a medicinal potential for developing anti-glioma agents. In the present study, we developed an in vitro model of cobalamin deficiency in glioblastoma cells. Long-term treatment of cells with the cobalamin analogue, hydroxycobalamin [c-lactam] (HCCL) was applied to induce an increase of hypocobalaminemia biomarker. Cytometric assays demonstrated that vitamin B12 promoted glioblastoma cells proliferation, whereas the treatment of cells with HCCL caused a dramatic inhibition of cell proliferation and an induction of cell cycle arrest at the G2/M phase. Vitamin B12 counteracted all the observed effects of HCCL. In the in silico study, we characterized the molecular interactions between HCCL and transcobalamin II (TCII). We have demonstrated that HCCL shares similar interactions with TCII as naturally occurring cobalamins and therefore may act as a competitive inhibitor of this key transporter protein. We assessed the impact of HCCL on the mortality or developmental malformations of zebrafish embryos. Collectively, our findings suggest that the use of cobalamin transport antagonists as potential anti-glioma agents would be worth exploring further.


2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Mustafa M. Farouk ◽  
Guojie Wu ◽  
Deborah A. Frost ◽  
Maryann Staincliffe ◽  
Scott O. Knowles

The impact of the following on beef digestibility was determined by static in vitro methods: (1) age of cattle; (2) muscle rigor state, ultimate pH, and mincing/particle size; (3) muscle/meat cut; (4) organ meats; and (5) meat accompaniments. Results indicate that beef is more digestible from older compared to younger cattle; prerigor compared to postrigor meat; higher compared to lower ultimate pH meat; cuts with lower compared to higher collagen contents; finely compared to coarsely minced/ground meat; and organ (liver and kidney) compared to muscle meat. Beef digestibility is enhanced when cooked with mushroom and pumpkin and reduced with starchy foods such as rice and potatoes. The outcomes of this study provide a base for the scientific design of meals with beef as a central ingredient and digestibility as the main functionality of interest.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 103 ◽  
Author(s):  
Sabrina Sepúlveda-Rivas ◽  
Hans Fritz ◽  
Camila Valenzuela ◽  
Carlos Santiviago ◽  
Javier Morales

The number of biologic drugs has increased in the pharmaceutical industry due to their high therapeutic efficacy and selectivity. As such, safe and biocompatible delivery systems to improve their stability and efficacy are needed. Here, we developed novel cationic polymethacrylate-alginate (EE-alginate) pNPs for the biologic drug model lysozyme (Lys). The impact of variables such as total charge and charge ratios over nanoparticle physicochemical properties as well as their influence over in vitro safety (viability/proliferation and cell morphology) on HeLa cells was investigated. Our results showed that electrostatic interactions between the EE-alginate and lysozyme led to the formation of EE/alginate Lys pNPs with reproducible size, high stability due to their controllable zeta potential, a high association efficiency, and an in vitro sustained Lys release. Selected formulations remained stable for up to one month and Fourier transform-Infrared (FT-IR) showed that the functional groups of different polymers remain identifiable in combined systems, suggesting that Lys secondary structure is retained after pNP synthesis. EE-alginate Lys pNPs at low concentrations are biocompatible, while at high concentrations, they show cytotoxic for HeLa cells, and this effect was found to be dose-dependent. This study highlights the potential of the EE-alginate, a novel polyelectrolyte complex nanoparticle, as an effective and viable nanocarrier for future drug delivery applications.


REAKTOR ◽  
2014 ◽  
Vol 15 (2) ◽  
pp. 132 ◽  
Author(s):  
Nurul - Widiastuti ◽  
Farhanah Thalib ◽  
Didik Prasetyoko ◽  
Hamzah Fansuri

Abstract PARTICLE SIZE AND CRYSTAL CONFORMATION OF SYNTHESIZED ZEOLITE-A WITH TETRAPROPYLAMMONIUM HYDROXIDE (TPAOH) ADDITION. The aims of this research is to study the effect of tetrapropylammonium hydroxide (TPAOH) concentration in the synthesis of zeolite A to its physical characteristics such as crystallinity, crystal conformation and average crystal size. The zeolite A was synthesized with composition 3.165 Na2O : 1.000 Al2O3 : 1.926 SiO2 : 128 H2O : x TPAOH where x was 0; 0.0385; 0.0577; 0.0770; 0.1540 and 4.1602. The zeolite was crystalized under hydrothermal condition in a stainless steel autoclave at 100°C for 5 hours. The resulting crystal was washed with distilled water until pH 8 and then dried in an oven at 80oC for 24 hours. FT-IR and XRD analysis results show that the synthesized zeolite A at x = 4.1602 has the lowest crystallinity. It is estimated due to the mass of TPAOH was four times higger than the mass of zeolite framework components (Si and Al). SEM and PSD (Particle Size Distribution) analysis results show that TPAOH concentration affected the crystal conformation and the average size of zeolite A particles. The formation of chained crystal conformation was caused by the electrostatic interactions between TPA+ and negatively charge of zeolite framework. In addition, the particel size of the synthesized zeolite A at x = 0.1540 was 2.024 µm which was smaller than the particel size of the synthesized zeolite A without TPAOH, which was 3.534 µm. Keywords: average size of particles; crystal conformation; TPAOH; zeolite A Abstrak Penelitian ini bertujuan untuk mempelajari pengaruh konsentrasi TPAOH (Tetrapropilamonium hidroksida) dalam sintesis zeolit A terhadap sifat fisikanya yang meliputi kekristalan, konformasi kristal dan ukuran rata-rata kristal yang terbentuk. Pada penelitian   ini   zeolit A   disintesis    dengan komposisi 3,165 Na2O : 1 Al2O3 : 1,926 SiO2 :128 H2O: x TPAOH. Konsentrasi TPAOH divariasikan dengan nilai x adalah 0; 0,0385; 0,0577; 0,0770; 0,1540 dan 4,1602. Metode hidrotermal digunakan dalam penelitian ini dengan kondisi suhu  hidrotermal 100°C dan waktu kristalisasi selama 5 jam dengan pH pencucian 8. Hasil karakterisasi menggunakan FT-IR (Fourier Transform – Infrared Spectroscopy) dan XRD (X-Ray Diffraction)  menunjukkan bahwa zeolit A yang disintesis dengan x = 4,1602 memiliki kekristalan terendah. Hal ini diperkirakan terjadi karena masa TPAOH yang digunakan empat kali lebih besar daripada masa penyusun zeolit (Si dan Al). Berdasarkan hasil karakterisasi menggunakan SEM (Scanning Electron Microscopy) dan PSD (Particle Size Distribution), dapat diketahui bahwa TPAOH berpengaruh terhadap konformasi kristal dan rata-rata ukuran kristalnya.  Terbentuknya konformasi kristal seperti rantai disebabkan oleh adanya interaksi elektrostatik antara muatan positif pada TPA+ dan muatan negatif dari kerangka zeolit. Zeolit A yang disintesis dengan x = 0,1540 memiliki ukuran partikel rata-rata 2,024 µm yang lebih kecil dari daripada zeolit A tanpa TPAOH yaitu sebesar 3,534 µm. Kata kunci : ukuran partakel rata-rata; konformasi kristal; TPAOH; zeolite A 


2000 ◽  
Vol 2000 ◽  
pp. 61-61
Author(s):  
F.L. Mould ◽  
D. Colombatto ◽  
E. Owen

The extent of rumen degradability of a feedstuff depends on the interaction between rate of degradation and residence time. In situ techniques require that substrates are ground to obtain a homogenous sample and to reduce result variability. However undegraded feed particle losses increase with bag pore size and fineness of grinding. If these particles are degraded at a similar or lower rate than the retained material, degradability, especially for short-term incubations, will be overestimated. In contrast if the feed particles lost are more readily degraded the degradability measurements obtained will be unaffected. Where improvements due to grinding have been recorded in situ these are assumed to result from variations in the proportion of fine particles that are immediately soluble or rapidly degradable. Gas-based in vitro feed evaluation systems offer the possibility of quantifying this effect directly and a study was therefore conducted to investigate the impact of particle size on the rate and extent of fermentation using the Reading Pressure Technique (Mauricio et al., 1999).


Author(s):  
Mohammad Ali Saghiri ◽  
Steven M Morgano ◽  
Hamed Kazerani ◽  
Shuying Jiang ◽  
James L Gutmann ◽  
...  

Introduction: The thickness threshold for detecting endodontic biomaterials depends on many factors, such as the nature of the radiopacifier and the particle size. Aim: The aim of this study was to determine the effect of thickness on radiodensity of various endodontic biomaterials; and evaluate the impact of radiopacifier particle size on radiodensity. Materials and Methods: This in-vitro study was conducted between August 2018 to December 2019. The study was divided in two parts, in first part, Six endodontic biomaterials (AH26, EndoSequence, Endoseal Mineral Trioxide Aggregate (MTA), Nano-MTA, Endocem Zr, and MTA without radiopacifier) were selected and evaluated in different thicknesses, in second part, MTA mixed with Bismuth oxide 10 μm, 200 μm, 120 nm (Groups 1-3), and Zirconium oxide 5 μm, 1 μm and 20 nm (Groups 4-6) were placed in frames with 1 mm, 0.5 mm, 0.2 mm, 0.1 mm thicknesses to evaluate the radiopacity. Results: The mean radiodensity was significantly different among various thickness (p<0.001) and materials (p<0.001). The changes of the radiodensity in various thickness from one material to the other were not uniform (interaction p-value <0.001). A 1 mm thickness had highest radiodensity (206.6±83.99), followed by 0.5 mm (68.9±24.6), 0.2 mm (17.9±4.9), and 0.1 mm thick material had least radiodensity (11.97±4.37). Materials of AH26 (99.1±103.2), Nano MTA (97.4±104.9), Endoseal MTA (87.86±101.4), Endosequence BC sealer (85.5±93.87) and Endocem Zr (71.88±77.67) were significantly different from the control group (16.38±10.85). The size of particles played important role in radiodensity (p<0.001). The radiodensity of Fine GIII (100 nm) material (112.68±108.47) was significantly higher than other materials: Thin GII (200 nm) (100.9±102.4), Fine GVI (20-40 nm) (99.7±95.1), Coarse GI (10 μm) (76.66±74.75), Thin GV (1~3 μm) (63.19±67.3), Coarse GIV (5 μm) (49.66±51.59) and MTA without Radiopaque Agent GVII (100%) (23.67±19.68). The effect of the thickness on radiodensity was different for each biomaterial, with significant differences from the control group. Conclusion: One of the readily available methods for increasing radiodensity is to increase the amount of radiopacifier, which might compromise the physical properties of the material. Fine particle radiopacifier (120 nm) with 1 mm thickness has significantly higher radiodensity than any other biomaterials in this study. Within the limitations of the current study, it can be concluded that the radiopacifier particle size has a significant impact on the level of radiodensity of dental biomaterials. Finding the optimum distribution, size, and geometry of radiopacifier particles within the same fraction rate can enhance the radiodensity.


Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 144
Author(s):  
Nouran S. Sharaf ◽  
Amro Shetta ◽  
Jailan E. Elhalawani ◽  
Wael Mamdouh

In an attempt to prove biological activity enhancement upon particle size reduction to the nanoscale, coffee (Cf) was chosen to be formulated into poly(lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) using the single emulsion-solvent evaporation (SE-SE) method via Box–Behnken Design (BBD) to study the impact of certain process and formulation parameters on the particle size and size homogeneity, surface stability and encapsulation efficiency (EE%). The coffee-loaded PLGA (PLGA-Cf) NPs were characterized by different methods to aid in selecting the optimum formulation conditions. The desirable physicochemical characteristics involved small particle sizes with an average of 318.60 ± 5.65 nm, uniformly distributed within a narrow range (PDI of 0.074 ± 0.015), with considerable stability (Zeta Potential of −20.50 ± 0.52 mV) and the highest EE% (85.92 ± 4.01%). The antioxidant and anticancer activities of plain PLGA NPs, pure Cf and the optimum PLGA-Cf NPs, were evaluated using 2,2-Diphenyl-1-picryl-hydrazyl (DPPH) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, respectively. As a result of nano-encapsulation, antioxidant activity was enhanced by 26.5%. Encapsulated Cf showed higher anticancer potency than pure Cf against different cancerous cell lines with an increase of 86.78%, 78.17%, 85.84% and 84.84% against MCF-7, A-549, HeLa and HepG-2, respectively. The in vitro release followed the Weibull release model with slow and biphasic release profile in both tested pH media, 7.4 and 5.5.


Sign in / Sign up

Export Citation Format

Share Document