CommentPublished: 24 April 2026Felix Horns1,2,Victoria Tobin3 &Michael B. Elowitz3,4 Nature Reviews Bioengineering (2026)Cite this articleSubjectsCell deliveryGenetic vectorsNucleic-acid therapeuticsDelivering mRNA to specific cell types remains challenging. Recent work opens the possibility of using synthetic RNA transfer pathways to engineer mRNA ‘delivery cells’. These cells could home to disease sites, locally produce and deliver mRNA to target cells, and thereby enable targeted editing, reprogramming or elimination of selected cells for therapeutic benefit.This is a preview of subscription content, access via your institutionAccess optionsSubscribe to this journalReceive 12 digital issues and online access to articles118,99 € per yearonly 9,92 € per issueLearn moreBuy this articlePurchase on SpringerLinkInstant access to the full article PDF.39,95 €Prices may be subject to local taxes which are calculated during checkoutFig. 1: Engineered cells as programmable delivery systems.The alternative text for this image may have been generated using AI.ReferencesParhiz, H., Atochina-Vasserman, E. N. & Weissman, D. mRNA-based therapeutics: looking beyond COVID-19 vaccines. Lancet 403, 1192–1204 (2024).Article Google Scholar Mittelbrunn, M. et al. Unidirectional transfer of microRNA-loaded exosomes from T cells to antigen-presenting cells. Nat. 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M.B.E. is a Howard Hughes Medical Institute investigator.Author informationAuthors and AffiliationsArc Institute, Palo Alto, CA, USAFelix HornsDepartment of Genetics, Stanford University, Stanford, CA, USAFelix HornsDivision of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USAVictoria Tobin & Michael B. ElowitzHoward Hughes Medical Institute and Department of Applied Physics, California Institute of Technology, Pasadena, CA, USAMichael B. ElowitzAuthorsFelix HornsView author publicationsSearch author on:PubMed Google ScholarVictoria TobinView author publicationsSearch author on:PubMed Google ScholarMichael B. ElowitzView author publicationsSearch author on:PubMed Google ScholarCorresponding authorsCorrespondence to Felix Horns or Michael B. Elowitz.Ethics declarationsCompeting interestsF.H. and M.B.E. have patent applications filed by the California Institute of Technology (US application numbers 17/820,232 and 17/820,235) related to cell-based RNA delivery.Rights and permissionsReprints and permissionsAbout this article