Skip to main content
2025 BMES Annual Meeting Main banner
Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.
ViewAttendees 5

Drug Delivery

CNS Drug Delivery

Nucleic Acid Delivery via Engineered Extracellular Vesicles for Neurofibromatosis Type 1 Therapy

Friday, October 10, 2025
4:45 PM - 5:00 PM PDT
Location: Room 29C

Introduction: :

Introduction: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder caused by the loss of function of neurofibromin protein due to mutations in the NF1 gene. The loss of function of Neurofibromin results in the overactivation of RAS protein, leading to uncontrolled cellular proliferation and tumor development. Patients with Neurofibromatosis develop plexiform neurofibromas (pNFs), benign nerve sheath tumors primarily composed of Schwann cells, which can undergo malignant transformation into highly aggressive malignant peripheral nerve sheath tumors (MPNSTs). Gene therapies for Neurofibromatosis using viral drug delivery systems are limited due to the NF1 gene size. To overcome this limitation, extracellular vesicles (EVs) and engineered EVs (eEVs) have emerged as promising non-viral therapeutic carriers; For this reason, this research focuses on the restoration of neurofibromin protein function via delivery of NF1 cargo (e.g., mRNA, protein, and NF1 plasmid) loaded in eEVs as a novel therapeutic strategy for Neurofibromatosis type 1.

Materials and

Methods: : Materials and methods: Primary mouse embryonic fibroblasts (PMEFs) were used to generate NF1-engineered EVs via nano-electroporation with plasmids encoding human NF1. EVs were isolated from culture media, and successful loading of NF1 genetic material was confirmed using RT-PCR. Particle characteristics such as zeta potential, size distribution, and concentration were analyzed using ZetaView. Fibroblasts and Schwann cells were isolated from a SOX10-CreER(T2); NF1^flox/flox mouse model after 9 months of tamoxifen induction to develop 3D plexiform neurofibroma (pNF)-like spheroids. These spheroids were treated with NF1-loaded EVs to assess therapeutic efficacy. Additionally, in vivo studies were conducted using tissue nano-transfection (TNT) to transfect skin with NF1-encoding plasmids and evaluate whether the skin could produce and deploy therapeutic EVs targeting peripheral organs.

Results, Conclusions, and Discussions::

Results: PMEFs successfully produced NF1-loaded EVs, confirmed by RT-PCR, with PCMV6-transfected cells serving as negative controls (Figure 1A). Nano-electroporation did not significantly alter EV biophysical properties, including zeta potential and particle concentration (Figure 1B–C). Isolated fibroblasts and Schwann cells from the NF1 mouse model formed stable 3D pNF-like spheroids. NF1-loaded EVs were efficiently taken up by these spheroids, resulting in detectable NF1 mRNA levels (Figure 1D), reduced expression of SOX9, and increased expression of apoptotic markers (Caspase-3 and BAD) (Figure 1E). In vivo TNT of skin with NF1-encoding plasmids enabled the skin to produce EVs capable of delivering plasmid DNA to enlarged dorsal root ganglia (DRGs), as well as to peripheral nerves such as the sciatic nerve (Figure 1F–I).
Discussion and conclusions:
These findings demonstrate the potential of NF1-loaded EVs as a non-viral gene therapy platform for NF1. EVs derived from transfected skin cells can successfully deliver therapeutic nucleic acids (mRNA or plasmid DNA) to affected peripheral tissues, including DRGs and sciatic nerves. This strategy offers a promising alternative for restoring neurofibromin function in NF1 and warrants further investigation into preclinical models.

Acknowledgements and/or References (Optional)::