In vitro models for peripheral nerve regeneration.

Area of Science:

• Neuroscience
• Regenerative Medicine
• Biomedical Ethics

Background:

• Peripheral nerve injuries are common, with suboptimal clinical outcomes and incomplete functional recovery.
• Current therapeutic strategies include trophic factors, biomaterials, and nerve prostheses.
• Pre-clinical validation using animal models is essential but ethically constrained by the need to limit animal use.

Purpose of the Study:

• To rank available in vitro models for peripheral nerve regeneration.
• To provide a framework for selecting models based on ethical considerations and scientific goals.
• To guide researchers in adhering to the Three Rs (Replacement, Reduction, Refinement) principles in animal research.

Main Methods:

• A three-step stair model was adopted to rank in vitro models.
• Models were categorized based on increasing ethical impact: cell line-based, primary cell-based, and organotypic ex vivo-based.
• Ethical impact was assessed by considering the necessity and extent of animal use.

Main Results:

• Cell line-based models present no ethical concerns.
• Primary cell-based models have a low ethical impact due to limited animal use.
• Organotypic ex vivo-based models have moderate ethical concerns, requiring animal use but with reduced impact compared to in vivo studies.

Conclusions:

• The tiered model facilitates the selection of appropriate in vitro models for peripheral nerve regeneration research.
• This approach supports ethical research practices by prioritizing models with lower ethical impact.
• Researchers can align experimental design with scientific objectives while minimizing animal use.