Tissue-specific melt electrowritten polymeric scaffolds for coordinated regeneration of soft and hard periodontal tissues

Periodontitis is a chronic inflammatory condition that often causes serious damage to tooth-supporting tissues. The limited successful outcomes of clinically available approaches underscore the need for therapeutics that cannot only provide structural guidance to cells but can also modulate the local immune response. Here, three-dimensional melt electrowritten (i.e., poly(ε-caprolactone)) scaffolds with tissue-specific attributes were engineered to guide differentiation of human-derived periodontal ligament stem cells (hPDLSCs) and mediate macrophage polarization. The investigated tissue-specific scaffold attributes comprised fiber morphology (aligned vs. random) and highly-ordered architectures with distinct strand spacings (small 250 μm and large 500 μm). Macrophages exhibited an elongated morphology in aligned and highly-ordered scaffolds, while maintaining their round-shape on randomly-oriented fibrous scaffolds. Expressions of periostin and IL-10 were more pronounced on the aligned and highly-ordered scaffolds. While hPDLSCs on the scaffolds with 500 μm strand spacing show higher expression of osteogenic marker (Runx2) over 21 days, cells on randomly-oriented fibrous scaffolds showed upregulation of M1 markers. In an orthotopic mandibular fenestration defect model, findings revealed that the tissue-specific scaffolds (i.e., aligned fibers for periodontal ligament and highly-ordered 500 μm strand spacing fluorinated calcium phosphate [F/CaP]-coated fibers for bone) could enhance the mimicking of regeneration of natural periodontal tissues.