Back to 2026 Abstracts

---

Coupling Microsurgery and Bioengineering to Guide Vascular Patterning and Maturation in a Calvarial Defect Model
MohammadHossein Asgardoon^*1, Deepak Gupta², Neekita Jikaria¹, Jenn Park¹, Mary Landmesser¹, Paul Armatowicz¹, Ibrahim Ozbolat², Dino Ravnic^1
1Surgery, Penn State University, Hershey, PA; ²Engineering Science and Mechanics, Pennsylvania State University, University Park, PA

Background:
Micropuncture (MP) of macrovessels induces a localized pro-angiogenic environment that can be leveraged to vascularize implanted biomaterials. We previously showed that MP of the sagittal sinus rapidly vascularizes adjacent scaffolds. However, the role of scaffold microarchitecture in guiding vascular patterning and maturation remains unclear. We hypothesize that channeled scaffolds will permit oriented angiogenesis, leading to increased endothelial cell ingrowth and vascular maturation compared with non-channeled scaffolds.
Methods:
An 8-mm calvarial bone defect was created in Sprague-Dawley rats. MP of the sagittal sinus was performed using a 60 µm microneedle at 1-mm intervals prior to scaffold implantation. Channeled and non-channeled scaffolds (n = 4 per group; Fig. 1A) were fabricated from gelatin methacrylate using 3D-printed air templates, photocrosslinked with 405 nm light, and aligned with the underlying sagittal sinus. On day 14, scaffolds were explanted and stained for histology (H&E) and the following cell markers: CD31 (endothelial cells), NG2 and αSMA (pericytes), and counterstained with DAPI. Quantitative image analysis was performed using ImageJ and GraphPad Prism.
Results:
In channeled scaffolds, H&E staining showed longitudinally aligned vessels extending from the sagittal sinus (Fig. 1B). Immunofluorescence revealed numerous luminal structures corresponding to channel dimensions, lined by endothelial cells, and surrounded by pericytes (Fig. 1C). In contrast, non-channeled scaffolds contained fewer endothelial cells with random patterns and minimal pericyte support (Fig. 1D-F).
Conclusion:
Scaffold microarchitecture influences vascular patterning and maturation following sagittal sinus micropuncture. Channel architecture promotes the formation of larger-diameter vessels with enhanced perivascular support, shifting the vascular phenotype toward a more organized, stable network. These findings suggest that engineered physical guidance within biomaterials can be used to direct microvascular growth and maturation.
Models adjusted for BMI, tissue expander size, and axillary irradiation. OR > 1 indicates higher odds with early exchange.

---

Back to 2026 Abstracts