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Esbjörner, E. K.

Publications and source records attributed to Esbjörner, E. K..

2 recordsLinked to original sources

Advanced Peptide Nanoparticles Enable Robust and Efficient delivery of gene editors across cell types

Efficient delivery of the CRISPR/Cas9 system and its larger derivatives, base editors, and prime editors remain a significant challenge, particularly in tissue-specific stem cells and induced pluripotent stem cells (iPSCs). This study optimized a novel family of cell-penetrating peptides, hPep, to deliver gene-editing ribonucleoproteins. The hPep-based nanoparticles enable highly efficient and biocompatible delivery of Cre recombinase, Cas9, base-, and prime editors. Using base editors, robust and nearly complete genome editing was achieved in the human cells: HEK293T (96%), iPSCs (74%), and muscle stem cells (80%). This strategy opens promising avenues for ex vivo and, potentially, in vivo applications. Incorporating silica particles enhanced the systems versatility, facilitating cargo-agnostic delivery. Notably, the nanoparticles can be synthesized quickly on a benchtop and stored as lyophilized powder without compromising functionality. This represents a significant advancement in the feasibility and scalability of gene-editing delivery technologies.

bioengineering↗

Stealth fluorescence labeling for live microscopy imaging of mRNA delivery

Methods for tracking of RNA molecules inside living cells are critical to probe their dynamics and biological functions, but also to monitor delivery of therapeutic RNA. We here describe a method for fluorescence labeling of RNAs of any length, via the enzymatic incorporation of the minimally perturbing and intrinsically fluorescent tricyclic cytosine analogue tCO. Using this approach, we demonstrate incorporation of tCO in up to 100% of all natural cytosine positions of a 1.2 kb mRNA encoding for the histone H2B fused to GFP (H2B:GFP). The resulting transcript is fully compatible with both in vitro transcription and subsequent in cell translation. Spectroscopic characterization of the in vitro transcribed mRNA, shows that the incorporation rate of tCO is on par with cytosine, facilitating efficient labeling and controlled tuning of labeling ratios for different applications. Using live cell confocal microscopy and flow cytometry, we show that the tCO-labeled mRNA is efficiently and correctly translated into H2B:GFP upon electroporation as well as lipid-mediated transfection of human Huh-7 cells; correct translation was further confirmed in cell-free systems. Importantly, the spectral properties of the tCO-modified transcripts and their translation product, in this case H2B:GFP, allow for their straightforward and simultaneous visualization in live cells.Competing Interest StatementAnders Dahlen is an employee of AstraZeneca and may hold shares in the company.View Full Text

biochemistry↗