scholarly journals Synthesis and Properties of Low-Molecular-Weight PEI-Based Lipopolymers for Delivery of DNA

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1060 ◽  
Author(s):  
Miao-Miao Xun ◽  
Zheng Huang ◽  
Ya-Ping Xiao ◽  
Yan-Hong Liu ◽  
Ji Zhang ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Molecular Weight ◽  
Transfection Efficiency ◽  
Dna Delivery ◽  
Low Molecular Weight ◽  
Zeta Potentials ◽  
Poor Efficacy ◽  
Mcf 7

Rapid enzymatic degradation and fragmentation during DNA administration can result in limited gene expression, and consequently, poor efficacy. It is necessary to use novel vectors for DNA delivery. Herein, we aimed to design useful carriers for enhancing transfection efficiency (TE). These lipopolymers were prepared through Michael addition reactions from low-molecular-weight (LMW) polyethyleneimine (PEI) and linkers with three kinds of steroids. Agarose gel electrophoresis assay results displayed that the three lipopolymers could condense plasmid DNA well, and the formed polyplexes had appropriate sizes around 200–300 nm, and zeta potentials of about +25–40 mV. The results of in vitro experiments using HeLa, HEK293, and MCF-7 cells showed that these lipopolymers present higher TE than 25-kDa PEI, both in the absence and presence of 10% serum. Flow cytometry and confocal microscopy studies also demonstrated that these lipopolymer/DNA complexes present higher cellular uptake and intracellular distribution. The measurement of critical micelle concentration (CMC) revealed that these lipopolymers could form micelles, which are suited for drug delivery. All results suggest that the three materials may serve as hopeful candidates for gene and drug delivery in future in vivo applications.

scholarly journals A Low-Molecular-Weight Polyethylenimine/pDNA-VEGF Polyplex System Constructed in a One-Pot Manner for Hindlimb Ischemia Therapy

Pharmaceutics ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 171 ◽  
Author(s):  
Xiaoshuang Guo ◽  
Zihan Yuan ◽  
Yang Xu ◽  
Xiaotian Zhao ◽  
Zhiwei Fang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gene Delivery ◽  
High Efficiency ◽  
Transfection Efficiency ◽  
Low Molecular Weight ◽  
Physical Interaction ◽  
Hindlimb Ischemia ◽  
One Pot

Peripheral arterial disease (PAD) is often characterized by continued reduction in blood flow supply to limbs. Advanced therapeutic strategies like gene therapy could potentially be applied to limb ischemia therapy. However, developing a gene delivery system with low toxicity and high efficiency remains a great challenge. In this study, a one-pot construction was used to integrate vector synthesis and polyplex fabrication simultaneously in a simple and robust manner. We fabricated an interpenetrating gene delivery network through the physical interaction between low-molecular-weight polyethylenimine (PEI 1.8 kDa) and plasmid DNA (pDNA) and the chemical bonding between PEI and glutaraldehyde (GA), which was named the glutaraldehydelinked-branched PEI (GPEI) polyplex. The final GPEI polyplex system was pH-responsive and biodegradable due to the imine linkage and it could successfully deliver desired vascular endothelial growth factor (VEGF) pDNA. Compared with PEI (25 kDa)/pDNA polyplexes, GPEI polyplexes showed lower cytotoxicity and higher transfection efficiency both in vitro and in vivo. In addition, we demonstrated that GPEI polyplexes could efficiently promote the formation of new capillaries in vivo, which may provide a practicable strategy for clinical hindlimb ischemia therapy in the future.

The Influence of Fumaric Anhydride on Bioadhesive Polymer Compositions

1998 ◽  
Vol 550 ◽  
Author(s):  
C.A. Santos ◽  
B.D. Freedman ◽  
S. Ghosn ◽  
E. Mathiowitz
Keyword(s):  
Drug Delivery ◽  
Molecular Weight ◽  
Fumaric Acid ◽  
Intestinal Lumen ◽  
Low Molecular Weight ◽  
Molar Ratios ◽  
Work Measurement ◽  
Bioadhesive Polymers

AbstractBioadhesive polymers are useful as drug delivery systems designed to adhere to the gastrointestinal lumen. The interaction between polymer and mucosal tissue influences residence time of the polymeric device and greatly affects the bioavailability of encapsulated drug. Poly(fumaric-co-sebacic anhydride) [P(FA:SA)] demonstrated impressive results in a variety of in vitro and in vivo experiments designed to test bioadhesion of microspheres. Among different molar ratios of P(FA:SA), adhesive measurements increased with increasing fumaric acid (FA) content. Using a modified microbalance technique, P(FA:SA)10:90 yielded a tensile work measurement of 82.99±12.76 nJ (mean±SEM) while that for P(FA:SA)70:30 was 453.23±47.73 nJ. A low molecular weight substance, fumaric anhydride prepolymer (FAPP), the oligomer form of fumaric acid, was incorporated into the microspheres and greatly increased the bioadhesive properties of P(FA:SA) as well as those of the relatively non-bioadhesive polymer poly(caprolactone) (PCL). Tensile work of P(FA:SA)20:80 was 32.95±5.42 nJ, and P(FA:SA)20:80 with 25% FAPP yielded a tensile work measurement of 556.28±113.12 nJ. Adhesion testing with PCL yielded a tensile work measurement of 7.93±1.84 nJ, while that for PCL with 25% FAPP was 1629.54±307.55 nJ. The effect of FA on drug delivery was evaluated in vitro using the P(FA:SA):FAPP blend with the everted intestinal sac technique. A low molecular weight drug (sodium salicylate) encapsulated in P(FA:SA)20:80 passed through the everted intestinal lumen to the interior of the sac to yield a concentration of 11.17±0.93 mg/dL, and drug encapsulated in P(FA:SA)20:80 with 10% FAPP yielded a concentration of 16.25±1.68 mg/dL (P<0.05). Unencapsulated drug passed through the intestinal lumen to yield a concentration of 8.09±-0.36 mg/dL. These experiments demonstrate that fumaric anhydride could be a very important component in bioadhesive polymer systems.

Effects of Unfractionated and Low Molecular Weight Heparins on Platelet Thromboxane Biosynthesis “In Vivo”

1994 ◽  
Vol 72 (06) ◽  
pp. 942-946 ◽  
Author(s):  
Raffaele Landolfi ◽  
Erica De Candia ◽  
Bianca Rocca ◽  
Giovanni Ciabattoni ◽  
Armando Antinori ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Low Molecular Weight Heparin ◽  
Primary Source ◽  
In Vivo Studies ◽  
Low Molecular Weight ◽  
Heparin Administration ◽  
To Receive

SummarySeveral “in vitro” and “in vivo” studies indicate that heparin administration may affect platelet function. In this study we investigated the effects of prophylactic heparin on thromboxane (Tx)A2 biosynthesis “in vivo”, as assessed by the urinary excretion of major enzymatic metabolites 11-dehydro-TxB2 and 2,3-dinor-TxB2. Twenty-four patients who were candidates for cholecystectomy because of uncomplicated lithiasis were randomly assigned to receive placebo, unfractionated heparin, low molecular weight heparin or unfractionaed heparin plus 100 mg aspirin. Measurements of daily excretion of Tx metabolites were performed before and during the treatment. In the groups assigned to placebo and to low molecular weight heparin there was no statistically significant modification of Tx metabolite excretion while patients receiving unfractionated heparin had a significant increase of both metabolites (11-dehydro-TxB2: 3844 ± 1388 vs 2092 ±777, p <0.05; 2,3-dinor-TxB2: 2737 ± 808 vs 1535 ± 771 pg/mg creatinine, p <0.05). In patients randomized to receive low-dose aspirin plus unfractionated heparin the excretion of the two metabolites was largely suppressed thus suggesting that platelets are the primary source of enhanced thromboxane biosynthesis associated with heparin administration. These data indicate that unfractionated heparin causes platelet activation “in vivo” and suggest that the use of low molecular weight heparin may avoid this complication.

Neutralization of a Low Molecular Weight Heparin (LHN-1) and Conventional Heparin by Protamine Sulfate in Rats

1986 ◽  
Vol 56 (03) ◽  
pp. 318-322 ◽  
Author(s):  
V Diness ◽  
P B Østergaard
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Thrombus Formation ◽  
Experimental Models ◽  
Protamine Sulfate ◽  
Low Molecular Weight ◽  
Antithrombotic Effect ◽  
Higher Doses

SummaryThe neutralization of a low molecular weight heparin (LHN-1) and conventional heparin (CH) by protamine sulfate has been studied in vitro and in vivo. In vitro, the APTT activity of CH was completely neutralized in parallel with the anti-Xa activity. The APTT activity of LHN-1 was almost completely neutralized in a way similar to the APTT activity of CH, whereas the anti-Xa activity of LHN-1 was only partially neutralized.In vivo, CH 3 mg/kg and LHN-1 7.2 mg/kg was given intravenously in rats. The APTT and anti-Xa activities, after neutralization by protamine sulfate in vivo, were similar to the results in vitro. In CH treated rats no haemorrhagic effect in the rat tail bleeding test and no antithrombotic effect in the rat stasis model was found at a protamine sulfate to heparin ratio of about 1, which neutralized APTT and anti-Xa activities. In LHN-1 treated rats the haemorrhagic effect was neutralized when APTT was close to normal whereas higher doses of protamine sulfate were required for neutralization of the antithrombotic effect. This probably reflects the fact that in most experimental models higher doses of heparin are needed to induce bleeding than to prevent thrombus formation. Our results demonstrate that even if complete neutralization of APTT and anti-Xa activities were not seen in LHN-1 treated rats, the in vivo effects of LHN-1 could be neutralized as efficiently as those of conventional heparin. The large fall in blood pressure caused by high doses of protamine sulfate alone was prevented by the prior injection of LHN-1.

Novel concatameric heparin-binding peptides reverse heparin and low-molecular-weight heparin anticoagulant activities in patient plasma in vitro and in rats in vivo

Blood ◽  
2004 ◽  
Vol 103 (4) ◽  
pp. 1356-1363 ◽  
Author(s):  
Barbara P. Schick ◽  
David Maslow ◽  
Adrianna Moshinski ◽  
James D. San Antonio
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Tandem Repeats ◽  
Factor Xa ◽  
Low Molecular Weight ◽  
Heparin Binding ◽  
High Affinity ◽  
Binding Peptides

Abstract Patients given unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) for prophylaxis or treatment of thrombosis sometimes suffer serious bleeding. We showed previously that peptides containing 3 or more tandem repeats of heparin-binding consensus sequences have high affinity for LMWH and neutralize LMWH (enoxaparin) in vivo in rats and in vitro in citrate. We have now modified the (ARKKAAKA)n tandem repeat peptides by cyclization or by inclusion of hydrophobic tails or cysteines to promote multimerization. These peptides exhibit high-affinity binding to LMWH (dissociation constant [Kd], ≈ 50 nM), similar potencies in neutralizing anti–Factor Xa activity of UFH and enoxaparin added to normal plasma in vitro, and efficacy equivalent to or greater than protamine. Peptide (ARKKAAKA)3VLVLVLVL was most effective in all plasmas from enoxaparin-treated patients, and was 4- to 20-fold more effective than protamine. Several other peptide structures were effective in some patients' plasmas. All high-affinity peptides reversed inhibition of thrombin-induced clot formation by UFH. These peptides (1 mg/300 g rat) neutralized 1 U/mL anti–Factor Xa activity of enoxaparin in rats within 1 to 2 minutes. Direct blood pressure and heart rate measurements showed little or no hemodynamic effect. These heparin-binding peptides, singly or in combination, are potential candidates for clinical reversal of UFH and LMWH in humans.

scholarly journals Novel Role for Albumin in Innate Immunity: Serum Albumin Inhibits the Growth of Blastomyces dermatitidis Yeast Form In Vitro

2003 ◽  
Vol 71 (11) ◽  
pp. 6648-6652 ◽  
Author(s):  
Steven Giles ◽  
Charles Czuprynski
Keyword(s):  
Molecular Weight ◽  
Inhibitory Activity ◽  
Mammalian Species ◽  
Blastomyces Dermatitidis ◽  
Low Molecular Weight ◽  
Rat Serum ◽  
Yeast Form ◽  
Domain Iii

ABSTRACT In this study we found that serum inhibitory activity against Blastomyces dermatitidis was principally mediated by albumin. This was confirmed in experiments using albumin from several mammalian species. Analbuminemic rat serum did not inhibit B. dermatitidis growth in vivo; however, the addition of albumin restored inhibitory activity. Inhibitory activity does not require albumin domain III and appears to involve binding of a low-molecular-weight yeast-derived growth factor.

HEMODIALYSIS OF THE RAT

1966 ◽  
Vol 44 (5) ◽  
pp. 849-859 ◽  
Author(s):  
Sumner M. Robinson ◽  
David A. Hurwitz ◽  
Robert Louis-Ferdinand ◽  
William F. Blatt
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Low Molecular Weight

A technique is described for hemodialysis of either anesthetized or non-restrained rats. In the apparatus the dialysis plates of an autoanalyzer system are used with only minor modification. The efficiency of this method has been evaluated with regard to the clearance of saccharides, both in vitro and in vivo, as well as the extraction of nitrogenous low molecular weight moieties from circulating blood. Approximately 50% of the dialyzable material was obtained in a 1-hour dialysis. Further fractionation of the dialyzate was accomplished by gel filtration (Sephadex G-25).

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