Sustained viral gene delivery through core-shell fibers

Area of Science:

• Biomaterials Science
• Gene Therapy
• Regenerative Medicine

Background:

• Viral gene transfer offers efficient transgene expression for tissue engineering but faces challenges like virus dissemination, toxicity, and transient expression due to immune responses.
• Current tissue engineering strategies often involve in vitro genetic modification of cells before in vivo transplantation.
• In situ transduction of progenitor cells by obviating in vitro manipulation is highly desirable for simplified therapeutic approaches.

Purpose of the Study:

• To fabricate virus-encapsulated electrospun fibrous scaffolds for sustained and localized gene transduction.
• To evaluate the efficacy and duration of transgene expression from the encapsulated virus.
• To assess the impact of virus encapsulation on macrophage activation and inflammatory responses.

Main Methods:

• Co-axial electrospinning was employed to encapsulate adenovirus encoding green fluorescent protein into the core of poly(epsilon-caprolactone) fibers.
• A porogen-mediated process was utilized for controlled release of the virus from the scaffold.
• HEK 293 cells and RAW 264.7 cells were used to assess transgene expression, duration, and inflammatory cytokine production.

Main Results:

• High-level transgene expression was observed in HEK 293 cells seeded on scaffolds for over a month, contrasting with transient expression from scaffold supernatant.
• RAW 264.7 cells cultured on virus-encapsulated fibers showed reduced production of inflammatory cytokines (IL-1β, TNF-α, IFN-α), indicating decreased macrophage activation.
• The core-shell poly(epsilon-caprolactone) fiber encapsulation effectively reduced viral vector-induced immune cell activation.

Conclusions:

• Virus-encapsulated electrospun scaffolds provide a viable strategy for sustained and localized gene transduction.
• This approach offers an attractive alternative to traditional viral gene transfer methods in regenerative medicine, mitigating immune responses and simplifying procedures.
• The developed scaffold technology holds promise for enhancing the safety and efficacy of gene therapy in tissue engineering applications.