A Hybrid Bioprinting Framework for Finger Regeneration: Suppressing Fibrotic Closure and Harnessing Endogenous Healing

This paper applies the Causal Hourglass framework (Wilcox, 2026) to the problem of post-amputation regeneration, proposing a hybrid bioprinting protocol that suppresses fibrotic closure (Effective Deterministic Closure, EDC) to extend the pre-EDC window for tissue integration. The framework combines existing technologies — 3D bioprinting, TGF-β inhibitors, stem cells, and bioelectric stimulation — in a timed two-phase protocol: Phase 1 suppresses the fibrotic response while bioprinted scaffolds are laid down; Phase 2 gradually reactivates endogenous healing once the scaffold is sufficiently integrated. The paper also introduces an extension of the framework to chronic amputees via proximal re-amputation — a proposed method for generating a fresh pre-EDC window at a healthy proximal site when the original wound site has undergone full post-EDC remodeling. This extension has direct implications for military and veteran populations whose injuries predate the availability of regenerative therapies. This is an alpha release. The author is an independent researcher, not a medical professional. The theoretical foundations are grounded in existing literature but this is a framework proposal, not a clinical study. Preclinical validation is the necessary next step. Collaboration, critique, and engagement from researchers, clinicians, and funders are actively invited.