Biology subjects

Metzloff, A. E.

Publications and source records attributed to Metzloff, A. E..

2 recordsLinked to original sources

bioRxiv2025

Anti-CD38-Targeted Piperazine-Derived Lipid Nanoparticles Overcome Hepatic Clearance for mRNA Delivery to Multiple Myeloma Cells In Vivo

Multiple myeloma (MM) is an incurable plasma cell malignancy characterized by clonal heterogeneity, immune evasion, and therapeutic resistance. Messenger RNA (mRNA) therapeutics offer programmable strategies to express therapeutic proteins and gene editors, but their efficacy is limited by poor extrahepatic delivery. To overcome these barriers, we developed a lipid nanoparticle (LNP) platform for targeted mRNA delivery to MM cells in vivo. Through combinatorial screening, we identified C16-O1, a piperazine-based ionizable lipid that efficiently transfects both CD138+ and therapy-resistant CD138-MM subclones. For tumor selectivity, LNPs were functionalized with an antibody fragment against CD38, a clinically validated MM antigen. Anti-CD38 LNPs reached the tumor-site and significantly reduced hepatic accumulation in murine xenografts. As an in vitro proof-of-concept, delivery of Cas9 mRNA and an IRF4-targeting guide RNA induced gene knockout, cell-cycle arrest, and lenalidomide sensitization. Together, these findings establish a robust framework for targeted mRNA delivery in MM and other hematologic malignancies.

bioengineering↗

bioRxiv2019

Litmus-Body: a Molecularly Targeted Sensor for Cell-Surface pH Measurements

Precise pH measurements in the immediate environment of receptors is essential for elucidating the mechanisms through which local pH changes associated with diseased phenotypes manifest into aberrant receptor function. However, current pH sensors lack the molecular specificity required to make these measurements. Herein we present the Litmus-body, our recombinant protein-based pH sensor, which through fusion to an anti-mouse IgG nanobody is capable of molecular targeting to specific proteins on the cell surface. By normalizing a pH-dependent green fluorescent protein to a long-Stokes shift red fluorophore or fluorescent protein, we readily report pH independent of sensor concentration using a single 488-nm excitation. Our Litmus-body showed excellent responsiveness in solution, with a greater than 50-fold change across the physiological regime of pH. The sensor was further validated for use on live cells, shown to be specific to the protein of interest, and was able to successfully recapitulate the numerous pH changes along the endocytic pathway.

cell biology↗