An anti-bacterial porous shape memory self-adaptive stiffened polymer for alveolar bone regeneration after tooth extraction.

Abstract

The regeneration of alveolar bone after tooth extraction is critical for the placement of dental implants. Developing a rigid porous scaffold with defect shape adaptability is of great importance but challenging for alveolar bone regeneration. Herein, we design and synthesize a biocompatible poly(l-glutamic acid)-<i>g</i>-poly(<i>ε</i>-caprolactone) (PLGA-<i>g</i>-PCL) porous shape memory (SM) polymer. The PLGA-<i>g</i>-PCL is then copolymerized with acryloyl chloride grafted poly(<i>ω</i>-pentadecalactone) (PPDLDA) having a higher phase transition temperature than shape recovery temperature to maintain stiffness after shape recovery to resist chewing force. The hybrid polydopamine/silver/hydroxyapatite (PDA/Ag/HA) is coated to the surface of (PLGA-<i>g</i>-PCL)-PPDL scaffold to afford the anti-bacterial activity. The porous SM scaffold can be deformed into a compact size and administered into the socket cavity in a minimally invasive mode, and recover its original shape with a high stiffness at body temperature, fitting well in the socket defect. The SM scaffold exhibits robust antibacterial activity against <i>Staphylococcus aureus</i> (<i>S. aureus</i>). The porous microstructure and cytocompatibility of PLGA allow for the ingrowth and proliferation of stem cells, thus facilitating osteogenic differentiation. The micro-CT and histological analyses demonstrate that the scaffold boosts efficient new bone regeneration in the socket of rabbit mandibular first premolar. This porous shape memory self-adaptive stiffened polymer opens up a new avenue for alveolar bone regeneration.