Biomimetic Periodontal Ligament Transplantation Activated by Gold Nanoparticles Protects Alveolar Bone.

Stem cell therapy might be a promising method to stimulate alveolar bone regeneration, which is currently a major clinical challenge. However, its therapeutic features largely depend on pretreatment and transplantation preparation. Herein, a novel biomimetic periodontal ligament transplantation composed of human periodontal ligament stem cells (hPDLSCs) pretreated with gold nanocomplexes (AuNCs) and embedded in a type-I collagen hydrogel scaffold is developed to protect alveolar bone from resorption. AuNCs were readily absorbed by primary hPDLSCs, with limited cytotoxicity, and promoted osteogenic differentiation of hPDLSCs effectively in vitro. In addition, the AuNCs-induced hPDLSCs were encapsulated with type-I collagen hydrogel scaffold to mimic their native physiological niche, and then transplanted into a rat model of alveolar bone resorption. Both micro-computed tomography (micro-CT) and immunohistochemical assays demonstrated that alveolar bone loss was significantly prevented. Furthermore, the underlying therapeutic mechanism was elucidated, in which transplantation-activated osteogenesis was associated with autophagy, which enabled bone remodeling and regeneration. This study provides critical insight into the role of PDLSCs in bone homeostasis and proposes an innovative AuNCs-based strategy for stem cell therapy in bone regeneration. This article is protected by copyright. All rights reserved.