Fluorescence- and computed tomography for assessing the biodistribution of siRNA after intratracheal application in mice

Geyer, Antonia; Lorenzer, Cornelia; Gehrig, Sebastian; Simlinger, Manuela; Winkler, Johannes; Sami, Haider; Ogris, Manfred

doi:10.1016/j.ijpharm.2017.02.025

Cited by 12 publications

(15 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“… 53 , 54 We have recently applied naked but chemically modified siRNA intratracheally demonstrating not only partial lung retention but also crossing of the air–blood barrier and renal excretion of intact siRNA. 24 Also, we could confirm that the AF750 dye remains attached to siRNA and the siRNA remains intact when analyzed in urine, making this a suitable method for tracking siRNA in vivo . Notably, the presence of intact siRNA in urine could be due to the employment of chemically modified siRNA, which showed better in vivo stability, which is crucial for its biological function.…”

Section: Resultsmentioning

confidence: 78%

“…This difference cannot be explained only due to the sheer differences in size: 2 nm; citrate-capped AuNPs remained in the lung with only minute amounts found in the liver, as per Sadauskas et al 57 In contrast, siRNA of a similar size (2 nm, when considering the hydrodynamic diameter) 58 crosses the air–blood barrier rapidly and efficiently and is excreted via kidneys. 24 , 55 Thus, in the case of auropolyplexes, the release of siRNA from gold AuNP seems unhampered, which can be advantageous from the standpoint of functionality. In contrast, covalently attached nucleic acid to the gold NP surface is not completely released where ∼60% remains surface-bound 13 and might not be accessible to the cellular machinery.…”

Section: Resultsmentioning

confidence: 99%

“…Image analysis of 2D epifluorescence and FLIT/CT imaging data was done with Living Image software, as described in detail elsewhere. 24 For 2D epifluorescence imaging data, background auto fluorescence (from animals) was distinguished from AF750 fluorescence by a spectral unmixing method. FLIT/CT imaging data was reconstructed to generate a virtual surface, which was then used for 3D analysis, enabling sagittal, coronal, and axial views.…”

Section: Methodsmentioning

confidence: 99%

“…We have established an imaging-based method for spatio-temporal tracking of siRNA in vivo by near-infrared fluorescence imaging, along with fluorescence imaging (FLIT) and X-ray absorption computed tomography (CT). 24 , 25 …”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Combined Chemisorption and Complexation Generate siRNA Nanocarriers with Biophysics Optimized for Efficient Gene Knockdown and Air–Blood Barrier Crossing

Taschauer

Polzer

Pöschl

et al. 2020

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

Current nucleic acid (NA) nanotherapeutic approaches face challenges because of shortcomings such as limited control on loading efficiency, complex formulation procedure involving purification steps, low load of NA cargo per nanoparticle, endosomal trapping, and hampered release inside the cell. When combined, these factors significantly limit the amount of biologically active NA delivered per cell in vitro , delivered dosages in vivo for a prolonged biological effect, and the upscalability potential, thereby warranting early consideration in the design and developmental phase. Here, we report a versatile nanotherapeutic platform, termed auropolyplexes, for improved and efficient delivery of small interfering RNA (siRNA). Semitelechelic, thiolated linear polyethylenimine (PEI) was chemisorbed onto gold nanoparticles to endow them with positive charge. A simple two-step complexation method offers tunable loading of siRNA at concentrations relevant for in vivo studies and the flexibility for inclusion of multiple functionalities without any purification steps. SiRNA was electrostatically complexed with these cationic gold nanoparticles and further condensed with polycation or polyethyleneglycol–polycation conjugates. The resulting auropolyplexes ensured complete complexation of siRNA into nanoparticles with a high load of ∼15,500 siRNA molecules/nanoparticle. After efficient internalization into the tumor cell, an 80% knockdown of the luciferase reporter gene was achieved. Auropolyplexes were applied intratracheally in Balb/c mice for pulmonary delivery, and their biodistribution were studied spatio-temporally and quantitatively by optical tomography. Auropolyplexes were well tolerated with ∼25% of the siRNA dose remaining in the lungs after 24 h. Importantly, siRNA was released from auropolyplexes in vivo and a fraction also crossed the air–blood barrier, which was then excreted via kidneys, whereas >97% of gold nanoparticles were retained in the lung. Linear PEI-based auropolyplexes offer a combination of successful endosomal escape and better biocompatibility profile in vivo . Taken together, combined chemisorption and complexation endow auropolyplexes with crucial biophysical attributes, enabling a versatile and upscalable nanogold-based platform for siRNA delivery in vitro and in vivo .

show abstract

Section: Resultsmentioning

confidence: 78%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Combined Chemisorption and Complexation Generate siRNA Nanocarriers with Biophysics Optimized for Efficient Gene Knockdown and Air–Blood Barrier Crossing

Taschauer

Polzer

Pöschl

et al. 2020

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

show abstract

“…Intratracheal administration of polyplex samples was conducted using a Microsprayer/Syringe Assembly (MSA-250-M; Penn Century, USA) as described by Geyer et al 19,52 Both LPEI-PEG-CD49f and LPEI-PEG were tested as polyplex formulations with pCpG-hCMV-EF1a-LucSH. Polyplexes were prepared at a final pDNA concentration of 267 mg/mL.…”

Section: In Vivo Transfection Assaymentioning

confidence: 99%

Peptide-Targeted Polyplexes for Aerosol-Mediated Gene Delivery to CD49f-Overexpressing Tumor Lesions in Lung

Taschauer

Polzer

Alioglu

et al. 2019

Molecular Therapy - Nucleic Acids

Self Cite

View full text Add to dashboard Cite

Peptide ligands can enhance delivery of nucleic acid-loaded nanoparticles to tumors by promoting their cell binding and internalization. Lung tumor lesions accessible from the alveolar side can be transfected, in principle, using gene vectors delivered as an aerosol. The cell surface marker CD49f (Integrin α6) is frequently upregulated in metastasizing, highly aggressive tumors. In this study, we utilize a CD49f binding peptide coupled to linear polyethylenimine (LPEI) promoting gene delivery into CD49f-overexpressing tumor cells in vitro and into lung lesions in vivo. We have synthesized a molecular conjugate based on LPEI covalently attached to the CD49f binding peptide CYESIKVAVS via a polyethylene glycol (PEG) spacer. Particles formed with plasmid DNA were small (<200 nm) and could be aerosolized without causing major aggregation or particle loss. In vitro, CD49f targeting significantly improved plasmid uptake and reporter gene expression on both human and murine tumor cell lines. For evaluation in vivo, localization and morphology of 4T1 murine triple-negative breast cancer tumor lesions in the lung of syngeneic BALB/c mice were identified by MRI. Polyplexes applied via intratracheal aerosolization were well tolerated and resulted in measurable transgene activity of the reporter gene firefly luciferase in tumor areas by bioluminescence imaging (BLI). Transfectability of tumors correlated with their accessibility for the aerosol. With CD49f-targeted polyplexes, luciferase activity was considerably increased and was restricted to the tumor area.

show abstract

Degradable Bottlebrush Polypeptides and the Impact of their Architecture on Cell Uptake, Pharmacokinetics, and Biodistribution In Vivo

Strasser

Montsch

Weiss

et al. 2023

Small

Self Cite

View full text Add to dashboard Cite

Bottlebrush polymers are highly promising as unimolecular nanomedicines due to their unique control over the critical parameters of size, shape and chemical function. However, since they are prepared from biopersistent carbon backbones, most known bottlebrush polymers are non‐degradable and thus unsuitable for systemic therapeutic administration. Herein, we report the design and synthesis of novel poly(organo)phosphazene‐g‐poly(α‐glutamate) (PPz‐g‐PGA) bottlebrush polymers with exceptional control over their structure and molecular dimensions (Dh ≈ 15–50 nm). These single macromolecules show outstanding aqueous solubility, ultra‐high multivalency and biodegradability, making them ideal as nanomedicines. While well‐established in polymer therapeutics, it has hitherto not been possible to prepare defined single macromolecules of PGA in these nanosized dimensions. A direct correlation was observed between the macromolecular dimensions of the bottlebrush polymers and their intracellular uptake in CT26 colon cancer cells. Furthermore, the bottlebrush macromolecular structure visibly enhanced the pharmacokinetics by reducing renal clearance and extending plasma half‐lives. Real‐time analysis of the biodistribution dynamics showed architecture‐driven organ distribution and enhanced tumor accumulation. This work, therefore, introduces a robust, controlled synthesis route to bottlebrush polypeptides, overcoming limitations of current polymer‐based nanomedicines and, in doing so, offers valuable insights into the influence of architecture on the in vivo performance of nanomedicines.

show abstract

Fluorescence- and computed tomography for assessing the biodistribution of siRNA after intratracheal application in mice

Cited by 12 publications

References 25 publications

Combined Chemisorption and Complexation Generate siRNA Nanocarriers with Biophysics Optimized for Efficient Gene Knockdown and Air–Blood Barrier Crossing

Combined Chemisorption and Complexation Generate siRNA Nanocarriers with Biophysics Optimized for Efficient Gene Knockdown and Air–Blood Barrier Crossing

Peptide-Targeted Polyplexes for Aerosol-Mediated Gene Delivery to CD49f-Overexpressing Tumor Lesions in Lung

Degradable Bottlebrush Polypeptides and the Impact of their Architecture on Cell Uptake, Pharmacokinetics, and Biodistribution In Vivo

Contact Info

Product

Resources

About