Gengaro, I. R. | bioRxiv Science

bioRxiv2026

Programmable Surface Receptor-Mediated Cell Targeting with Designer Antibody-Routed Nanoparticles (DARTs)

Precise in vivo delivery remains a massive barrier to therapeutic genome editing. Recently, major strides have been made towards cell type-specific delivery, with potential to improve the safety profiles of future gene therapies. However, programming such targeted tropism is limited by the minimal repertoire of scFv sequences, nanobodies, and viral fusogens that enable cell-type specificity, and the slow, iterative design-build-test cycle required to identify and optimize them. Here, we overcome this bottleneck by developing the designer antibody-routed (DART) platform: a modular, plug-and-play tool that decouples delivery vehicle production from tropism engineering. By presenting generic, bioorthogonal antibody-binding interfaces on the surfaces of enveloped particles, the DART system enables conjugation of those particles with off-the-shelf antibodies that direct cell entry without requiring genetic or chemical manipulation. Designer antibody-routed virus-like particles (DARTs) leverage this facile conjugation method to interrogate and identify transduction-competent surface antigens across cell types. They enable combinatorial targeting and the discovery of antigens that synergistically enhance transduction. Finally, DARTs function in the fetal murine nervous system, empirically identifying CD56 as a previously uncharacterized surface antigen enabling editing in hard-to-transduce neural populations. Overall, the DART platform provides a universal tool for rapidly profiling unique, targetable antigens and leveraging them for precision editing applications.

bioengineering↗

bioRxiv2021

Modular development enables rapid design of media for alternative hosts

Developing media to sustain cell growth and production is an essential and ongoing activity in bioprocess development. Modifications to media can often address host or product-specific challenges, such as low productivity or poor product quality. For other applications, systematic design of new media can facilitate the adoption of new industrially relevant alternative hosts. Despite manifold existing methods, common approaches for optimization often remain time and labor intensive. We present here a novel approach to conventional media blending that leverages stable, simple, concentrated stock solutions to enable rapid improvement of measurable phenotypes of interest. We applied this modular methodology to generate high-performing media for two phenotypes of interest: biomass accumulation and heterologous protein production, using high-throughput, milliliter-scale batch fermentations of Pichia pastoris as a model system. In addition to these examples, we also created a flexible open-source package for modular blending automation on a low-cost liquid handling system to facilitate wide use of this method. Our modular blending method enables rapid, flexible media development, requiring minimal labor investment and prior knowledge of the host organism, and should enable developing improved media for other hosts and phenotypes of interest.

microbiology↗