02005nas a2200349   4500000000100000000000100001008004100002260001500043653003000058653002300088100002000111700001500131700001600146700001500162700001900177700001500196700001300211700001800224700001600242700001900258700001400277700002300291700001500314700001600329700001200345245011600357856005500473300000900528490000700537520109700544022001401641       2025                            d  c2025-10-1610aHigh-throughput screening10aTissue engineering1 aS. Tori Ellison1 aIan Hayman1 aKristy Derr1 aPaige Derr1 aShayne Frebert1 aZina Itkin1 aMin Shen1 aAnthony Jones1 aWendy Olson1 aLawrence Corey1 aAnna Wald1 aChristine Johnston1 aYouyi Fong1 aMarc Ferrer1 aJia Zhu00aLimitations of acyclovir and identification of potent HSV antivirals using 3D bioprinted human skin equivalents  uhttps://www.nature.com/articles/s41467-025-64245-w  a92000 v163 aHerpes simplex virus (HSV) infection poses global public health concerns with lifelong impacts. Acyclovir, the standard therapy, has limited efficacy in preventing subclinical shedding, and drug resistance occurs in immunocompromised patients, highlighting the need for novel therapeutics. Here we show that acyclovir is significantly less effective in skin-derived keratinocytes than donor-matched fibroblasts. Using 3D bioprinted human skin equivalents (HSEs) in a 96-well plate format, we have screened 738 compounds with broad targets and mechanisms of action, identifying potent antivirals, including 23 known or experimental HSV treatments. Unlike acyclovir, antivirals against HSV helicase/primase or host replication pathways display similar potency across cell types and donor sources in both 2D and 3D models. The reduced potency in keratinocytes may explain acyclovir’s limited clinical efficacy. Our 3D bioprinted HSE assay platform enables the integration of patient-derived cells early in drug development and offers a physiologically relevant approach for HSV drug discovery.  a2041-1723