JSES - 2026-06-01 - Journal Article
Localized vitamin D delivery via 3D-printed nanofiber sheets combined with systemic supplementation enhances tendon-to-bone healing in a rabbit rotator cuff tear model: a preclinical study.
Rhee SM, Min YK, Park JH, Jeong HJ, Lee KH, Park SH, Oh JH
Topics
Key Takeaway
Combined systemic and localized 3D-printed nanofiber vitamin D delivery achieved the highest load-to-failure at 12 weeks post-repair (139.6 ± 25.3 N vs. 99.5–102.3 N in all other groups) in a rabbit rotator cuff model.
Summary Depth
Choose how much analysis to show on this article page.
Summary
This preclinical study tested whether combining systemic vitamin D supplementation with localized 3D-printed nanofiber vitamin D sheet delivery improves tendon-to-bone healing versus either intervention alone in a rabbit supraspinatus detachment-and-repair model. Sixty-four rabbits were randomized to four treatment groups assessed at 4 and 12 weeks. The dual-delivery group demonstrated superior load-to-failure (139.6 N vs. 99.5–102.3 N), highest collagen density, greatest COL1 mRNA expression at 4 weeks, and largest muscle fiber cross-sectional area at both time points.
Key Limitation
The rabbit supraspinatus model lacks translational fidelity to human massive rotator cuff tears in terms of tissue size, mechanical load, and the chronic degenerative muscle changes (Goutallier Grade III–IV fatty infiltration) that most complicate clinical repair outcomes.
Original Abstract
BACKGROUND
Vitamin D is crucial in musculoskeletal health, supporting bone, tendon, and muscle function. However, its localized delivery for tendon healing and muscle regeneration remains underexplored. We hypothesized that combining systemic and localized vitamin D delivery would enhance healing in a rotator cuff repair model.
METHODS
Sixty-four rabbits were randomly assigned to 2 main groups (n = 32), further divided into 4 subgroups (Group A, A': Normal diet + sheet without vitamin D; Group B, B': Normal diet + 3D-printed nanofiber-based vitamin D sheet (VTD sheet); Group C, C': systemic vitamin D supplementation (VTDS) + sheet without vitamin D; Group D, D': VTDS + VTD sheet, n = 8 each). The supraspinatus tendons were detached, left detracted for 6 weeks, and repaired using a transosseous method. Groups were assessed at 4- and 12-weeks post-repair. Outcomes included serum 25-OH vitamin D levels, gene expression of COL1, COL3, BMP-2, SCX, SOX9, and ACAN, histologic and biomechanical analysis, muscle fiber cross-sectional area, and vitamin D content in muscle via ELISA.
RESULTS
Serum vitamin D levels were highest in Group D and D' at the time of repair and extraction (P < .001). At 4 weeks post-repair, mRNA expression of COL1 was highest in Group D compared to the other groups (A, B, C, and D; 0.86 ± 0.25, 0.90 ± 0.27, 0.93 ± 0.19, and 1.06 ± 0.25, respectively, P = .046). At 12 weeks post-repair, Group D' exhibited the highest collagen density (P = .037) and had the greatest load to failure among all groups (A', B', C', D'; 102.3 ± 12.6 N, 99.5 ± 8.3 N, 102.3 ± 18.5 N, and 139.6 ± 25.3 N, respectively, P = .030). Regarding muscle regeneration, the cross-sectional area of muscle fiber was largest in Group D and D' at 4 and 12 weeks post-repair (P < .05). At 12 weeks after repair, muscle vitamin D levels, as measured by ELISA, were highest in Group D' (P = .003).
CONCLUSION
In this preclinical rabbit model, dual delivery of vitamin D using localized nanofiber sheets and systemic supplementation enhanced tendon-to-bone healing in a rotator cuff repair model and muscle regeneration compared to single interventions. These findings provide a foundation for future studies aimed at optimizing delivery methods and evaluating safety and efficacy in clinical settings.