Preclinical Experimental Study

Definition:
A preclinical experimental study is a type of biomedical research conducted before clinical trials in humans. It involves in vitro (cell-based) or in vivo (animal) models to investigate biological mechanisms, drug efficacy, toxicity, or disease processes.

• Subjects: Non-human (e.g., rats, mice, pigs, or cell lines)
• Purpose: To test hypotheses about disease mechanisms or potential treatments under controlled laboratory conditions.
• Interventions: May involve drugs, gene therapy, surgical techniques, or physical devices.
• Endpoints: Usually surrogate markers (e.g., protein expression, tumor volume, histological changes), not clinical outcomes.
• Level of evidence: Very low for clinical decision-making; designed to support or generate hypotheses, not guide patient care.

• Used to model neurological diseases (e.g., glioblastoma, spinal cord injury, intracranial aneurysms).
• Common in vascular neurosurgery to study angiogenesis, venous hypertension, or response to new embolic agents.
• Enables mechanistic insights prior to translation into human studies.

• Species differences: Animal physiology may not reflect human responses.
• Lack of external validity: Artificially induced disease may not replicate human pathology.
• No clinical outcomes: Cannot inform directly on therapeutic efficacy or safety in patients.
• Ethical considerations: Must follow strict animal welfare protocols.