Porous polydroxyalkanoates (PHA) scaffolds with antibacterial property for oral soft tissue regeneration

Due to the moist, warm and intricate oral environments, pathogenic bacteria pose a threat to periodontal health especially under the circumstances of soft tissue defects. Clinical practices employ commercial collagen mem-branes that often fail to combat opportunistic pathogens without antibiotic prophylaxis. Therefore, the design of gingival substitutes should take antibacterial property into account while facilitating the tissue regeneration process. Porous antibacterial scaffolds based on polyhydroxyalkanoates (PHA) containing 3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4HB) (P34HB) (or PAP34HB) for oral soft tissue regeneration were prepared in this study via a phase separation method with antibacterial property due to the presence of zinc oxide nano -particles (ZnO NPs). The resulted scaffolds favorably formed porous structures with reduced Young's modulus for patients' comfort feeling. In vitro studies using the scaffold exhibited better biocompatibility and antibacterial activity against oral-specific bacteria including Porphyromonas gingivalis and Streptococcus mutans compared to that of the commercial membranes. The scaffolds demonstrated significant improvements on the healing process even in the infectious intraoral wounds. The porous antibacterial scaffolds based on P34HB were revealed as a gingival substitute for oral soft tissue regeneration.