Smart Porous Scaffold Promotes Peri-Implant Osteogenesis under the Periosteum

Abstract

Background: Adequate peri-implant bone mass and bone quality are essential factors to ensure the initial stability of the implant and success of implant operation. In clinical settings, the lack of bone mass often restricts the implant operation. In this study, we fabricated a smart porous scaffold with a shape memory function and investigated whether it could promote peri-implant osteogenesis under the periosteum. Methods: A porous shape memory polymer (SMP) scaffold was fabricated and its shape memory function, mechanical properties, and degradation rate were tested in vitro. Moreover, the scaffold was implanted in the mandible of rabbits to evaluate its efficacy to promote peri-implant osteogenesis in the periosteum and enhance the initial stability of the implant. Histological, micro-CT, and biomechanical analyses were carried out for further verification. Results: The SMP scaffold has a good shape memory function and biocompatibility in vitro. In vivo experiments demonstrated that the SMP scaffold could recover to its original shape after implantation to create a small gap in the periosteum. After 12 weeks, the scaffold was gradually replaced by a newly formed bone, and the stability of the implant increased when it implanted with the scaffold. Conclusion: The present study indicates that the SMP scaffolds have a good shape memory function and could enhance peri-implant bone formation under the periosteum. The SMP scaffold provides a clinical potential candidate for bone tissue engineering under the periosteum.

Trace Element-Augmented Titanium Implant With Targeted Angiogenesis and Enhanced Osseointegration in Osteoporotic Rats

“…Modified implant surfaces have been found to alter bone turnover in osteoporotic patients to stimulate functional osseointegration ( Lotz et al, 2020 ). Micro–nano porous structures provide space for nutrition, vascularization, and finally bone ingrowth and implant fixation for the balance of load transfer ( Gorgin Karaji et al, 2017 ; He et al, 2020 ). With regard to the phase composition, XRD shows that the surface coating was mainly composed of anatase TiO 2 before treatment while attributive diffraction peaks of rutile phase also appeared after zinc doping ( Figure 3B ), which suggests that zinc content have influence over the nanocrystalline structure of the coatings.…”

The Current Status, Prospects, and Challenges of Shape Memory Polymers Application in Bone Tissue Engineering

“…Recent studies have invented interventions for periosteal distraction osteogenesis based on intramembranous osteogenesis, which means that additional external forces are applied, or the periosteum is slightly stripped from the bone surface, or a scaffold is implanted between the bone and the periosteum to form a subperiosteal gap between the surface of the periosteum and the bone, thus inducing the production of new bone [ 84 , 85 , 86 ]. Therefore, He et al [ 73 ] used this principle to co-implant a titanium implant and an SMP scaffold made of PCL-HA into the rabbit mandible, which recovered its shape after about 1 min in PBS at 37 °C and was able to form a small gap between the periosteum and the bone. The final results showed that the SMP scaffold was gradually replaced by newly formed bone at 12 weeks after implantation and that the stability of the implant accompanying the scaffold implant was increased.…”