Evaluating the Biocompatibility and Efficacy of Absorbable Three-Dimensional Micro-Nanofiber Scaffolds for Volume Restoration Following Post-Mastectomy Breast Reconstruction: An Experimental Study

<b>Background/Objectives:</b> As the incidence of breast cancer increases, reliable, effective, and innovative solutions are required for breast deformities following breast-conserving surgery. We aimed to evaluate the biocompatibility and efficacy of optimized three-dimensional (3D) micro-nanofiber scaffolds and demonstrate their clinical potential through preclinical experiments. <b>Methods:</b> Seven-week-old male Sprague-Dawley rats were randomized into four groups. Group I (control group) received a 2-dimensional (2D) micro-nanofiber scaffold weighing 0.2 g; Groups II-IV received 3D micro-nanofiber scaffolds weighing 0.2, 0.3, and 0.6 g, respectively. These were subcutaneously implanted into the dorsal region and harvested with the surrounding tissues at 4, 8, and 16 weeks for histological evaluation. <b>Results:</b> The number of inflammatory cells was higher in Group IV than in Groups II and III at 4 weeks, with a significant increase in Group IV (<i>p</i> < 0.01) compared with that in Group I. At 8 weeks, it was significantly increased in Group III compared with that in Group I. Furthermore, at 16 weeks, it was significantly reduced in Group IV (<i>p</i> < 0.05) compared with that in Group I. The fibrosis depth in the 3D scaffolds revealed significant differences in Groups II, III, and IV (<i>p</i> < 0.001) compared with Group I at 4 weeks. The collagen fiber densities in the 3D groups were higher than those in the 2D group at 8 and 16 weeks. There were no statistically significant differences between the 3D groups. <b>Conclusions:</b> Absorbable 3D micro-nanofiber scaffolds enhance tissue integration and extracellular matrix formation following post-mastectomy breast reconstruction.