Development of a Reproducible Procedure for Plasmid DNA Encapsulation by Red Blood Cell Ghosts

Larson, Gretchen M.; Pieterse, Anton; Quick, Gwynneth; Bijl, Pieter van der; Zyl, Johann van; Hawtrey, A. O.

doi:10.2165/00063030-200418030-00005

Cited by 8 publications

(4 citation statements)

References 30 publications

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“…This is in accordance with the findings of Chittchang et al45 who found that the random coil is the native secondary structure of polylysine. Although hydrophobicity of poly- l -lysine significantly increases in the order; random coil < α-helix < β-sheet conformers,46 we know from our previous experience that complexes of poly- l -lysine and poly- l -glutamic acid have a degree of hydrophobicity, as we have shown that conjugates of polylysine electrostatically bind to DNA and make good cell-transfecting agents 47. Moreover, poly- l -lysine adopts a β-sheet conformation from the random coil during interaction with phospholipids 48.…”

Section: Discussionmentioning

confidence: 99%

The effect of a peptide-containing synthetic lung surfactant on gas exchange and lung mechanics in a rabbit model of surfactant depletion

Zyl¹,

Smith²,

Hawtrey³

2013

DDDT

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BackgroundCurrently, a new generation of synthetic pulmonary surfactants is being developed that may eventually replace animal-derived surfactants used in the treatment of respiratory distress syndrome. Enlightened by this, we prepared a synthetic peptide-containing surfactant (Synsurf) consisting of phospholipids and poly-l-lysine electrostatically bonded to poly-l-glutamic acid. Our objective in this study was to investigate if bronchoalveolar lavage (BAL)-induced acute lung injury and surfactant deficiency with accompanying hypoxemia and increased alveolar and physiological dead space is restored to its prelavage condition by surfactant replacement with Synsurf, a generic prepared Exosurf, and a generic Exosurf containing Ca2+.MethodsTwelve adult New Zealand white rabbits receiving conventional mechanical ventilation underwent repeated BAL to create acute lung injury and surfactant-deficient lung disease. Synthetic surfactants were then administered and their effects assessed at specified time points over 5 hours. The variables assessed before and after lavage and surfactant treatment included alveolar and physiological dead space, dead space/tidal volume ratio, arterial end-tidal carbon dioxide tension (PCO2) difference (mainstream capnography), arterial blood gas analysis, calculated shunt, and oxygen ratios.ResultsBAL led to acute lung injury characterized by an increasing arterial PCO2 and a simultaneous increase of alveolar and physiological dead space/tidal volume ratio with no intergroup differences. Arterial end-tidal PCO2 and dead space/tidal volume ratio correlated in the Synsurf, generic Exosurf and generic Exosurf containing Ca2+ groups. A significant and sustained improvement in systemic oxygenation occurred from time point 180 minutes onward in animals treated with Synsurf compared to the other two groups (P < 0.001). A statistically significant decrease in pulmonary shunt (P < 0.001) was found for the Synsurf-treated group of animals, as well as radiographic improvement in three out of four animals in that group.ConclusionIn general, surfactant-replacement therapy in the animals did not fully restore the lung to its prelavage condition. However, our data show that the formulated surfactant Synsurf improves oxygenation by lowering pulmonary shunt.

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Section: Discussionmentioning

confidence: 99%

The effect of a peptide-containing synthetic lung surfactant on gas exchange and lung mechanics in a rabbit model of surfactant depletion

Zyl¹,

Smith²,

Hawtrey³

2013

DDDT

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“…McNeil et al (36) and others (37,38) describe "scrape loading" as a means to transfer larger molecules across the cell membrane, but "scrape loading" of adherent A-NK cells with AP leads to heterogenous uptake and a significant loss of cells. Other techniques, such as red blood cell ghost fusion (39)(40)(41)(42) and electroporation (43)(44)(45)(46)(47) as a means to get enzymes across the cell membrane, also resulted in heterogeneous labeling and considerable cell loss when applied to the A-NK cells and were therefore not further pursued. In contrast, the ability of PTD to transduce A-NK cells with various molecules, such as FITC, AP, and beta-gal, was very impressive.…”

Section: Discussionmentioning

confidence: 99%

PTD-mediated Loading of Tumor-Seeking Lymphocytes with Prodrug-Activating Enzymes

Yang

Larsen

Zhang

et al. 2008

AAPS J

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Abstract. Using the approach of peptide transduction domain (PTD)-mediated loading of interleukin-2 (IL-2)-activated natural killer (A-NK) cells, tumor-seeking lymphocytes, with prodrug-activating enzymes, we primarily aim to generate a cytotoxic drug selectively within tumors and minimize damage to normal tissues. A-NK cells are able to accumulate selectively at tumor sites. While these cells by themselves possess significant antitumor effect in vivo, we suggest that they can also serve as Trojan horses, by bringing anticancer agents, such as prodrug-activating enzymes, selectively to tumors. We have successfully demonstrated in a mouse model that A-NK cells can be rapidly loaded with prodrugactivating enzymes, such as alkaline phosphatase (AP) and beta-galactosidase (beta-gal), in vitro using enzyme-conjugated peptide PTD5. Upon adoptive transfer into lung-tumor-bearing animals, the loaded A-NK cells are able to bring their cargo of the prodrug-activating enzymes selectively to pulmonary metastases. The targeting of the AP to the tumor tissues is highly specific, since more than a fivefold higher concentration of AP was found in the tumor tissues compared to the surrounding normal lung tissue at 24 h after injection. The approach of transporting prodrug-activating enzymes selectively into tumors clearly shows potential for future targeted chemotherapy. Ongoing studies in our laboratory are evaluating the antitumor efficacy of cellular-dependent enzyme prodrug therapy.KEY WORDS: activated natural killer cells; delivery; metastases in vivo; prodrug enzymes; protein transduction domain.

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“…Of course, multiple variations of this have been developed, like Hb precipitation with PEG [ 111 ], pre-incubation with a hypotonic drug solution and then hypertonic resealing [ 112 ], and gradual drug loading [ 109 ]. In the only recent paper on the efficient loading of RBC ghosts with plasmidic DNA [ 100 ], Larson et al pre-swelled them in hypotonic phosphate buffer, incubated with plasmidic DNA, than concluded with resealing, adding a hypertonic solution of sodium chloride. The hypotonic pre-swelling approach was commonly used in the 1980s to load RBC ghosts with both RNA and DNA.…”

Section: Erythrocyte-based Ddssmentioning

confidence: 99%

Nucleic Acid Delivery with Red-Blood-Cell-Based Carriers

Pelle

Kostevšek

2021

IJMS

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Gene therapy has the potential to become a staple of 21st-century medicine. However, to overcome the limitations of existing gene-delivery therapies, that is, poor stability and inefficient and delivery and accumulation of nucleic acids (NAs), safe drug-delivery systems (DDSs) allowing the prolonged circulation and expression of the administered genes in vivo are needed. In this review article, the development of DDSs over the past 70 years is briefly described. Since synthetic DDSs can be recognized and eliminated as foreign substances by the immune system, new approaches must be found. Using the body’s own cells as DDSs is a unique and exciting strategy and can be used in a completely new way to overcome the critical limitations of existing drug-delivery approaches. Among the different circulatory cells, red blood cells (RBCs) are the most abundant and thus can be isolated in sufficiently large quantities to decrease the complexity and cost of the treatment compared to other cell-based carriers. Therefore, in the second part, this article describes 70 years of research on the development of RBCs as DDSs, covering the most important RBC properties and loading methods. In the third part, it focuses on RBCs as the NA delivery system with advantages and drawbacks discussed to decide whether they are suitable for NA delivery in vivo.

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Development of a Reproducible Procedure for Plasmid DNA Encapsulation by Red Blood Cell Ghosts

Abstract: Transfection studies have demonstrated that pGL3 DNA carrying the luciferase gene is successfully transferred from RBC ghosts to recipient HeLa cells in culture under mild fusion conditions.

Cited by 8 publications

References 30 publications

The effect of a peptide-containing synthetic lung surfactant on gas exchange and lung mechanics in a rabbit model of surfactant depletion

The effect of a peptide-containing synthetic lung surfactant on gas exchange and lung mechanics in a rabbit model of surfactant depletion

PTD-mediated Loading of Tumor-Seeking Lymphocytes with Prodrug-Activating Enzymes

Nucleic Acid Delivery with Red-Blood-Cell-Based Carriers

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