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Merk, L.

Publications and source records attributed to Merk, L..

2 recordsLinked to original sources
bioRxiv2025

Fast, Bright and Reversible Rhodamine Tags for Live-Cell Imaging

We present Rho-tag and SiR-tag, engineered protein tags derived from bacterial multidrug-resistance proteins that bind unsubstituted (silicon-) rhodamines with nanomolar affinity, enabling fast, reversible, and fluorogenic protein labeling. In live cells, Rho-tag labeling occurs within seconds -- faster than HaloTag7 -- and the tags are compatible with super-resolution methods like STED, SMLM, and MINFLUX. The high specificity of Rho-tag and SiR-tag for unsubstituted rhodamines allows their use alongside HaloTag7 and SNAP-tag. In vivo applications are demonstrated by efficient neuronal labeling in zebrafish larvae.

bioengineering↗
bioRxiv2023

Development of an optimized, non-stem cell line for intranasal delivery of therapeutic cargo to the central nervous system

Neural stem cells (NSC) are considered to be valuable candidates for delivering a variety of anti-cancer agents to brain tumors, including oncolytic viruses. However, owing to the previously reported tumorigenic potential of NSC cell line after intranasal administration (INA), here we identified the human hepatic stellate cell line (LX-2) as a cell type capable of longer resistance to replication of oncolytic adenoviruses (OAV) as therapeutic cargo, and being non-tumorigenic after INA. Our data show that LX-2 cells can longer withstand the OAV XVir-N-31 replication and oncolysis than NSCs. By selecting the highly migratory cell population out of LX-2, an offspring cell line with a higher and more stable capability to migrate was generated. Additionally, as a safety backup, we applied genomic HSV-TK integration into LX-2 leading to the high vulnerability to Ganciclovir. Histopathological analyses confirmed the absence of neoplasia in the respiratory tracts and brains of immuno-compromised mice 3 months after INA of LX-2 cells. Our data suggest that LX-2 is a novel robust and safe cell line for delivering anti-cancer and other therapeutic agents to the brain.

molecular biology↗