scholarly journals Oral Delivery of Nucleic Acids with Passive and Active Targeting to the Intestinal Tissue Using Polymer-Based Nanocarriers

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1075
Author(s):  
Sagun Poudel ◽  
Prabhat R. Napit ◽  
Karen P. Briski ◽  
George Mattheolabakis

Despite the apparent advantages for long-term treatment and local therapies against intestinal diseases, the oral delivery of nucleic acids has been challenging due to unfavorable physiological conditions for their stability. In this study, a novel nanodelivery system of PEG-PCL nanoparticles with encapsulated nucleic acids–mannosylated PEI (Man-PEI) complexes was developed for intestinal delivery. We complexed model nucleic acids with Man-PEI at the optimal N/P ratio of 20:1 for in vitro and in vivo analyses. Cells were transfected in vitro and analyzed for gene expression, receptor-mediated uptake, and PEG-PCL nanoparticles’ toxicity. We also evaluated the nucleic acid’s stability in the nanocarrier during formulation, and under simulated gastrointestinal environments or the presence of nucleases. Finally, we assessed the biodistribution for the PEG-PCL nanoparticles with encapsulated complexes and their ability to transfect intestinal cells in vivo. Nucleic acids complexed with Man-PEI were protected from degradation against nucleases. In comparison to the parent compound PEI, Man-PEI transfected the cells with an overall higher potency. Competition assay indicated receptor-mediated endocytosis promoted by mannose receptors. The PEG-PCL nanoparticles with Man-PEI/plasmid complexes indicated minimal cytotoxicity. The nanocarrier successfully protected the complexes in a simulated gastric fluid environment and released them in a simulated intestinal fluid environment, promoted by the presence of lipases. The oral administration of the PEG-PCL nanoparticles with encapsulated Man-PEI/plasmid complexes transfected intestinal cells with the plasmid in vivo, while presenting a time-dependent progression through the intestines. Conclusively, our carrier system can deliver genetic material to the GI tract and actively target mannose receptor overexpressing cells.

2007 ◽  
Vol 51 (10) ◽  
pp. 3562-3567 ◽  
Author(s):  
Melissa E. Boyne ◽  
Todd J. Sullivan ◽  
Christopher W. amEnde ◽  
Hao Lu ◽  
Veronica Gruppo ◽  
...  

ABSTRACT Structure-based design was used to develop a focused library of A-ring-modified diphenyl ether InhA inhibitors. From this library of analogs, two high-affinity alkyl-substituted diphenyl ethers, 6PP and 8PP, were selected for advanced study into their in vitro activity against Mycobacterium tuberculosis clinical isolates, their in vivo properties, and their signature response mode of action. 6PP and 8PP demonstrated enhanced activity against whole bacteria and showed activity in a rapid macrophage model of infection. In addition, transcriptional profiling revealed that the A-ring modifications of 6PP and 8PP increased the specificity of each analog for InhA. Both analogs had substantially longer half-lives in serum than did the parent compound, exhibited a fivefold reduction in cytotoxicity compared to the parent compound, and were well tolerated when administered orally at 300 mg/kg of body weight in animal models. Thus, the A-ring modifications increased the affinity and whole-cell specificity of the compounds for InhA and increased their bioavailability. The next step in optimization of the pharmacophore for preclinical evaluation is modification of the B ring to increase the bioavailability to that required for oral delivery.


Author(s):  
Venu Madhav K ◽  
Somnath De ◽  
Chandra Shekar Bonagiri ◽  
Sridhar Babu Gummadi

Fenofibrate (FN) is used in the treatment of hypercholesterolemia. It shows poor dissolution and poor oral bioavailability after oral administration due to high liphophilicity and low aqueous solubility. Hence, solid dispersions (SDs) of FN (FN-SDs) were develop that might enhance the dissolution and subsequently oral bioavailability. FN-SDs were prepared by solvent casting method using different carriers (PEG 4000, PEG 6000, β cyclodextrin and HP β cyclodextrin) in different proportions (0.25%, 0.5%, 0.75% and 1% w/v). FN-SDs were evaluated solubility, assay and in vitro release studies for the optimization of SD formulation. Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) analysis was performed for crystalline and morphology analysis, respectively. Further, optimized FN-SD formulation evaluated for pharmacokinetic performance in Wistar rats, in vivo in comparison with FN suspension.  From the results, FN-SD3 and FN-SD6 have showed 102.9 ±1.3% and 105.5±3.1% drug release, respectively in 2 h. DSC and PXRD studies revealed that conversion of crystalline to amorphous nature of FN from FT-SD formulation. SEM studies revealed the change in the orientation of FN when incorporated in SDs. The oral bioavailability FN-SD3 and FN-SD6 formulations exhibited 2.5-folds and 3.1-folds improvement when compared to FN suspension as control. Overall, SD of FN could be considered as an alternative dosage form for the enhancement of oral delivery of poorly water-soluble FN.


Author(s):  
Chukwuebuka Umeyor ◽  
Uchechukwu Nnadozie ◽  
Anthony Attama

This study seeks to formulate and evaluate a solid lipid nanoparticle-based, solidified micellar carrier system for oral delivery of cefepime. Cefepime has enjoyed a lot of therapeutic usage in the treatment of susceptible bacterial infections; however, its use is limited due to its administration as an injection only with poor patient compliance. Since oral drug administration encourage high patient compliance with resultant effect in improved therapy, cefepime was formulated as solid lipid microparticles for oral delivery using the concept of solidified micellar carrier system. The carrier system was evaluated based on particle yield, particle size and morphology, encapsulation efficiency (EE %), and thermal analysis using differential scanning calorimeter (DSC). Preliminary microbiological studies were done using gram positive and negative bacteria. In vitro release study was performed using biorelevant media, while in vivo release study was performed in white albino rats. The yield of solid lipid microparticles (SLM) ranged from 84.2 – 98.0 %. The SLM were spherical with size ranges of 3.8 ± 1.2 to 42.0 ± 1.4 µm. The EE % calculated ranged from 83.6 – 94.8 %. Thermal analysis showed that SLM was less crystalline with high potential for drug entrapment. Microbial studies showed that cefepime retained its broad spectrum anti-bacterial activity. In vitro release showed sustained release of cefepime from SLM, and in vivo release study showed high concentration of cefepime released in the plasma of study rats. The study showed that smart engineering of solidified micellar carrier system could be used to improve oral delivery of cefepime.


Author(s):  
Narendar Dudhipala ◽  
Arjun Narala ◽  
Dinesh Suram ◽  
Karthik Yadav Janga

The objective of this present study is to develop a semisolid dispersion (SSD) of zaleplon with the aid of self-emulsifying lipid based amphiphilic carriers (TPGS E or Gelucire 44/14) addressing the poor solubility of this drug. A linear relationship between the solubility of drug with respect to increase in the concentration of lipid surfactant in aqueous medium resulting in AL type phase diagram was observed from phase solubility studies. Fusion method was employed to obtain semisolid dispersions (SSD) of zaleplon which showed high content uniformity of drug. The absence of chemical interactions between the pure drug, excipients and formulations were conferred by Fourier transmission infrared spectroscopic examinations. The photographic images from polarized optical microscopic studies revealed the change in crystalline form of drug to amorphous or molecular state. The superior dissolution parameters of zaleplon from SSD over pure crystalline drug interpreted from in vitro dissolution studies envisage the ability of these lipid surfactants as solubility enhancers. Further, the caliber of TPGS E or Gelucire 44/14 in encouraging the GI absorption of drug was evident with the higher human effective permeability coefficient and fraction oral dose of drug absorbed from SSD in situ intestinal permeation study. In conclusion, in vivo studies in Wister rats demonstrated an improvement in the oral bioavailability of zaleplon from SSD over control pure drug suspension suggesting the competence of Gelucire 44/14 and TPGS E as conscientious carriers to augment the dissolution rate limited bioavailability of this active


2020 ◽  
Vol 17 (3) ◽  
pp. 229-245
Author(s):  
Gang Wang ◽  
Junjie Wang ◽  
Rui Guan

Background: Owing to the rich anticancer properties of flavonoids, there is a need for their incorporation into drug delivery vehicles like nanomicelles for safe delivery of the drug into the brain tumor microenvironment. Objective: This study, therefore, aimed to prepare the phospholipid-based Labrasol/Pluronic F68 modified nano micelles loaded with flavonoids (Nano-flavonoids) for the delivery of the drug to the target brain tumor. Methods: Myricetin, quercetin and fisetin were selected as the initial drugs to evaluate the biodistribution and acute toxicity of the drug delivery vehicles in rats with implanted C6 glioma tumors after oral administration, while the uptake, retention, release in human intestinal Caco-2 cells and the effect on the brain endothelial barrier were investigated in Human Brain Microvascular Endothelial Cells (HBMECs). Results: The results demonstrated that nano-flavonoids loaded with myricetin showed more evenly distributed targeting tissues and enhanced anti-tumor efficiency in vivo without significant cytotoxicity to Caco-2 cells and alteration in the Trans Epithelial Electric Resistance (TEER). There was no pathological evidence of renal, hepatic or other organs dysfunction after the administration of nanoflavonoids, which showed no significant influence on cytotoxicity to Caco-2 cells. Conclusion: In conclusion, Labrasol/F68-NMs loaded with MYR and quercetin could enhance antiglioma effect in vitro and in vivo, which may be better tools for medical therapy, while the pharmacokinetics and pharmacodynamics of nano-flavonoids may ensure optimal therapeutic benefits.


2020 ◽  
Vol 20 (11) ◽  
pp. 821-830
Author(s):  
Prasad Pofali ◽  
Adrita Mondal ◽  
Vaishali Londhe

Background: Current gene therapy vectors such as viral, non-viral, and bacterial vectors, which are used for cancer treatment, but there are certain safety concerns and stability issues of these conventional vectors. Exosomes are the vesicles of size 40-100 nm secreted from multivesicular bodies into the extracellular environment by most of the cell types in-vivo and in-vitro. As a natural nanocarrier, exosomes are immunologically inert, biocompatible, and can cross biological barriers like the blood-brain barrier, intestinal barrier, and placental barrier. Objective: This review focusses on the role of exosome as a carrier to efficiently deliver a gene for cancer treatment and diagnosis. The methods for loading of nucleic acids onto the exosomes, advantages of exosomes as a smart intercellular shuttle for gene delivery and therapeutic applications as a gene delivery vector for siRNA, miRNA and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and also the limitations of exosomes as a gene carrier are all reviewed in this article. Methods: Mostly, electroporation and chemical transfection are used to prepare gene loaded exosomes. Results: Exosome-mediated delivery is highly promising and advantageous in comparison to the current delivery methods for systemic gene therapy. Targeted exosomes, loaded with therapeutic nucleic acids, can efficiently promote the reduction of tumor proliferation without any adverse effects. Conclusion: In the near future, exosomes can become an efficient gene carrier for delivery and a biomarker for the diagnosis and treatment of cancer.


2015 ◽  
Vol 51 (37) ◽  
pp. 7887-7890 ◽  
Author(s):  
Hideto Maruyama ◽  
Kazuhiro Furukawa ◽  
Hiroyuki Kamiya ◽  
Noriaki Minakawa ◽  
Akira Matsuda

Synthetic chemically modified nucleic acids, which are compatible with DNA/RNA polymerases, have great potential as a genetic material for synthetic biological studies.


2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S7-S8
Author(s):  
Safina Gadeock ◽  
Cambrian Liu ◽  
Brent Polk

Abstract Tumor necrosis factor (TNF) is a highly expressed cytokine in inflammatory bowel disease (IBD). Although TNF can induce colonic epithelial dysfunction and apoptosis, recent studies suggest that TNF signalling promotes epithelial wound repair and stem cell function. Here we investigated the role of TNF receptor 1 (TNFR1) in mediating TNF’s effects on colonic epithelial stem cells, integral to mucosal healing in colitis. We demonstrate that Tnfr1-/- mice exhibit loss in Lgr5 expression (-52%, p<0.02; N=6) compared to wildtype (WT) controls. However, the opposite result was found in vitro, wherein murine Tnfr1-/- colonoids demonstrated a significant increase in Lgr5 expression (66%, p<0.007; N=6) compared to WT colonoids. Similarly, human colonoids treated with an anti-TNFR1 antibody also demonstrated an increase in Lgr5 expression, relative to IgG controls. To resolve the contradiction in the in vivo versus in vitro environment, we hypothesized that mesenchymal TNFR1 expression regulates the epithelial stem cell niche. To determine the relationships between these cell types, we co-cultured WT or Tnfr1-/- colonoids with WT or Tnfr1-/- colonic myofibroblasts (CMFs). We found that epithelial Lgr5 expression was significantly higher (by 52%, p<0.05; N=3) when co-cultured with WT compared to TNFR1-/- myofibroblasts. The loss of TNFR1 expression in vivo increases the number of αSMA+ mesenchymal cells by nearly 56% (N=6) but considerably reduces the pericryptal PDGFRα+ cells, suggesting modifications in mesenchymal populations that contribute to the epithelial stem cell niche. Functionally, primary Tnfr1-/--CMFs displayed PI3k (p<0.001; N=3) and MAPK (p<0.01; N=3)-dependent increases in migration, proliferation, and differentiation, but RNA profiling demonstrated by diminished levels of stem cell niche factors, Rspo3 (-80%, p<0.0001; N=6) and Wnt2b (-63%, p<0.008; N=6) compared to WT-CMFs. Supplementation with 50ng recombinant Rspo3 for 5 d to Lgr5-GFP organoids co-cultured with TNFR1-/--CMFs restored Lgr5 expression to wildtype levels. Therefore, TNFR1-mediated TNF signalling in mesenchymal cells promotes their ability to support an epithelial stem cell niche. These results should motivate future studies of the stem cell niche in the context of long-term treatment with anti-TNF therapies.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1210
Author(s):  
Xieguo Yan ◽  
Shiqiang Wang ◽  
Kaoxiang Sun

Schizophrenia, a psychiatric disorder, requires long-term treatment; however, large fluctuations in blood drug concentration increase the risk of adverse reactions. We prepared a long-term risperidone (RIS) implantation system that can stabilize RIS release and established in-vitro and in-vivo evaluation systems. Cumulative release, drug loading, and entrapment efficiency were used as evaluation indicators to evaluate the effects of different pore formers, polymer ratios, porogen concentrations, and oil–water ratios on a RIS implant (RIS-IM). We also built a mathematical model to identify the optimized formulation by stepwise regression. We also assessed the crystalline changes, residual solvents, solubility and stability after sterilization, in-vivo polymer degradation, pharmacokinetics, and tissue inflammation in the case of the optimized formulation. The surface of the optimized RIS microspheres was small and hollow with 134.4 ± 3.5 µm particle size, 1.60 SPAN, 46.7% ± 2.3% implant drug loading, and 93.4% entrapment efficiency. The in-vitro dissolution behavior of RIS-IM had zero-order kinetics and stable blood concentration; no lag time was released for over three months. Furthermore, the RIS-IM was not only non-irritating to tissues but also had good biocompatibility and product stability. Long-acting RIS-IMs with microspheres and film coatings can provide a new avenue for treating schizophrenia.


1985 ◽  
Vol 13 (4) ◽  
pp. 261-266
Author(s):  
P.P. Monro ◽  
D.P. Knight ◽  
W.S. Pringle ◽  
D.M. Fyfe ◽  
J.R. Shearer

The toxicity of implant materials requires investigation prior to clinical use. We have developed a method where materials are directly applied to the chorioallantoic membrane (CAM) of 9-day-old chick embryos and toxicity is assessed using histological criteria. We evaluated the method using metal foils. The number and organisation of fibroblasts seemed to be the most useful criteria for assessing metal toxicity. Differences were greatest after 10 days of culture on the CAM. The method is sensitive enough to enable us to discriminate between the less toxic aluminium and titanium and the highly toxic cobalt, nickel and tungsten. The proposed method has advantages over in vitro techniques which provide an abnormal fluid environment and in which the more complex interactions that are possible between implant materials and tissue in vivo cannot be modelled.


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