title: Nanosensors for Continuous and Noninvasive Monitoring of Mesenchymal Stem Cell Osteogenic Differentiation.
abstract: Assessing mesenchymal stem cell (MSC) differentiation status is crucial to verify therapeutic efficacy and optimize treatment procedures. Currently, this involves destructive methods including antibody-based protein detection and polymerase chain reaction gene analysis, or laborious and technically challenging genetic reporters. Development of noninvasive methods for real-time differentiation status assessment can greatly benefit MSC-based therapies. This report introduces a nanoparticle-based sensing platform that encapsulates two molecular beacon (MB) probes within the same biodegradable polymeric nanoparticles. One MB targets housekeeping gene glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as an internal reference, while another detects alkaline phosphatase (ALP), a functional biomarker. Following internalization, MBs are gradually released as the nanoparticle degrades. GAPDH MBs provide a stable reference signal throughout the monitoring period (18 days) regardless of differentiation induction. Meanwhile, ALP mRNA undergoes well-defined dynamics with peak expression observed during early stages of osteogenic differentiation. By normalizing ALP-MB signal with GAPDH-MB, changes in ALP expression can be monitored, to noninvasively validate osteogenic differentiation. As proof-of-concept, a dual-colored nanosensor is applied to validate MSC osteogenesis on 2D culture and polycaprolactone films containing osteo-inductive tricalcium phospate.
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, Singapore.
authors.forename: Christian
authors.initials: C
authors.lastname: Wiraja
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, Singapore.
authors.forename: David C
authors.initials: DC
authors.lastname: Yeo
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, Singapore.
authors.forename: Mark S K
authors.initials: MS
authors.lastname: Chong
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, Singapore.|NTU-Northwestern Institute for Nanomedicine, Nanyang Technological University, 50 Nanyang Avenue, Singapore, Singapore.
authors.forename: Chenjie
authors.initials: C
authors.lastname: Xu
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002130:Calcium Phosphates / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects; D036103:Nanotechnology / Q000295:instrumentation*; D010012:Osteogenesis / Q000187:drug effects; D011091:Polyesters / Q000494:pharmacology
chemical_list: D002130:Calcium Phosphates; D011091:Polyesters; C016240:polycaprolactone; C018392:tricalcium phosphate
keywords: bone regeneration; mesenchymal stem cells; molecular beacons; nanosensors; osteogenic differentiation