{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T16:32:49Z","timestamp":1790267569484,"version":"4.1.0"},"reference-count":48,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,4,20]],"date-time":"2026-04-20T00:00:00Z","timestamp":1776643200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Key R and D Program of China, MOST","award":["2023YFC2509900"],"award-info":[{"award-number":["2023YFC2509900"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["82272292"],"award-info":[{"award-number":["82272292"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["82472581"],"award-info":[{"award-number":["82472581"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"award":["82272292"],"award-info":[{"award-number":["82272292"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]},{"award":["82472581"],"award-info":[{"award-number":["82472581"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100010877","name":"Shenzhen Basic Research Program","doi-asserted-by":"publisher","award":["JCYJ20220531101805012"],"award-info":[{"award-number":["JCYJ20220531101805012"]}],"id":[{"id":"10.13039\/501100010877","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pharmaceutics"],"abstract":"<jats:p>Background\/Objectives: Bone-targeted drug delivery systems hold great promise for treating skeletal diseases, yet the optimal strategy for functionalizing lipid nanoparticles (LNPs) with bone-homing ligands remains insufficiently explored. Herein, we compared two alendronate sodium (Alen) modification approaches (pre-conjugation and post-conjugation) for constructing bone-targeted LNPs capable of delivering mRNA to skeletal tissues. Methods: LNPs were fabricated via microfluidic mixing, and the 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-polyethylene glycol-alendronate conjugate (DSPE-PEG-Alen) required for the pre-conjugation method was synthesized. The bone-targeting ability of LNPs prepared by the two Alen modification strategies was evaluated using an in vitro hydroxyapatite (HAP) binding assay. Furthermore, the physicochemical properties, bone-targeting performance, mRNA delivery efficiency, and biosafety of the LNPs prepared by the post-conjugation method were assessed through cellular uptake, in vivo imaging, and other methods. Results: Hydroxyapatite binding assays revealed that the post-conjugation strategy afforded significantly superior bone affinity compared to the pre-conjugation approach. In addition, ex vivo bone fragment binding experiments further confirmed that the bone-targeting LNPs prepared by the post-conjugation method exhibited stronger bone-binding capability compared to unmodified LNPs. The optimized Alen-LNPs demonstrated efficient cellular uptake and functional mRNA translation in bone marrow mesenchymal stem cells with negligible cytotoxicity. In vivo studies in mice confirmed the preferential accumulation of Alen-LNPs in bone tissues, with successful green fluorescent protein (GFP) mRNA translation detected in bone tissue sections. Histopathological analysis confirmed the biosafety of the formulation. Conclusions: This study establishes the post-conjugation strategy as the superior approach for Alen functionalization of LNPs, providing a robust and reproducible platform for bone-targeted mRNA therapeutics.<\/jats:p>","DOI":"10.3390\/pharmaceutics18040509","type":"journal-article","created":{"date-parts":[[2026,4,20]],"date-time":"2026-04-20T13:22:47Z","timestamp":1776691367000},"page":"509","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Microfluidic Fabrication of Alendronate-Modified Lipid Nanoparticles for Bone-Targeted mRNA Delivery"],"prefix":"10.3390","volume":"18","author":[{"given":"Kangling","family":"Xu","sequence":"first","affiliation":[{"name":"School of Pharmacy, Shenzhen University Medical School, Shenzhen University, Shenzhen 518055, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Junyu","family":"Su","sequence":"additional","affiliation":[{"name":"School of Basic Medical Sciences, Shenzhen University Medical School, Shenzhen University, Shenzhen 518055, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3397-6766","authenticated-orcid":false,"given":"Hailin","family":"Ma","sequence":"additional","affiliation":[{"name":"School of Basic Medical Sciences, Shenzhen University Medical School, Shenzhen University, Shenzhen 518055, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yanxia","family":"Zhu","sequence":"additional","affiliation":[{"name":"School of Basic Medical Sciences, Shenzhen University Medical School, Shenzhen University, Shenzhen 518055, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"364","DOI":"10.1016\/S0140-6736(18)32112-3","article-title":"Osteoporosis","volume":"393","author":"Compston","year":"2019","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1016\/j.jtemb.2012.03.017","article-title":"Osteoporosis and trace elements\u2014An overview","volume":"26","author":"Aaseth","year":"2012","journal-title":"J. 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