2025/12/12 by Philip Gade Knak, Marta Vittani, Ashley Bomin Lee +9 · 1 voice
Biochemistry, Genetics and Molecular Biology · Engineering · #Advanced Fluorescence Microscopy Techniques #Virus-based gene therapy research #Nanoplatforms for cancer theranostics
paper · pdf · doi:10.1117/1.nph.12.s2.s22811
openalex created_date 2025/12/12 · openalex publication_date 2025/12/12 · openalex updated_date 2026/08/01
SignificanceInvestigating blood microcirculation is important to better understand cardiovascular, metabolic, and neurodegenerative diseases. Although visualization of microcirculation has traditionally relied on the injection of short-lived fluorescent tracers, this approach poses challenges for experiments in awake animals or long-term imaging. To address these limitations, we previously developed a genetically encoded fluorescent plasma label that enables stable, minimally invasive in vivo visualization of vascular dynamics. Further optimizing its versatility and delivery will expand its utility in neuroscience and across diverse areas of biomedical research.AimWe aim to extend the utility of genetically encoded plasma labeling by testing brighter, more photostable fluorescent proteins and evaluating strategies to enhance adeno-associated viral (AAV)-mediated expression.ApproachAAV8 vectors encoding albumin fused to mNeonGreen or StayGold variants were administered systemically. Expression levels were tracked via blood sampling, and the effects of secondary AAV injection and immunomodulation were tested.ResultsAlb-mStayGold showed improved photostability but lower brightness than Alb-mNeonGreen. Secondary intraperitoneal AAV delivery successfully induced transgene expression even after prior AAV exposure. Moreover, higher AAV8-induced plasma label expression in males is confirmed. Immunosuppressant treatment increased plasma fluorescence, whereas neonatal AAV injection failed to induce tolerance.ConclusionPhotostable plasma labeling and immune modulation strategies expand the applicability of AAV-based vascular imaging.