A novel bioactive osteogenesis scaffold delivers ascorbic acid, β-glycerophosphate, and dexamethasone in vivo to promote bone regeneration.

Chao Wang,Yongxian Zhang,Xuecheng Cao

doi:10.18632/oncotarget.15779

Abstract

Ascorbic acid, β-glycerophosphate, and dexamethasone have been used in osteogenesis differentiation medium for in vitro cell culture, nothing is known for delivering these three bioactive compounds in vivo. In this study, we synthesized a novel bioactive scaffold by combining these three compounds with a lysine diisocyanate-based polyurethane. These bioactive compounds were released from the scaffold during the degradation process. The cell culture showed that the sponge-like structure in the scaffold was critical in providing a large surface area to support cell growth and all degradation products of the polymer were non-toxic. This bioactive scaffold enhanced the bone regeneration as evidenced by increasing the expression of three bone-related genes including collagen type I, Runx-2 and osteocalcin in rabbit bone marrow stem cells (BMSCs) in vitro and in vivo. The osteogenesis differentiation of BMSCs cultured in this bioactive scaffold was similar to that in osteogenesis differentiation medium and more extensive in this bioactive scaffold compared to the scaffold without these three bioactive compounds. These results indicated that the scaffold containing three bioactive compounds was a good osteogenesis differentiation promoter to enhance the osteogenesis differentiation and new bone formation in vivo.

Highlights

Bone defects are commonly caused by injury, trauma, infection or cancer and a large bone defect is difficult to repair
The osteogenesis differentiation of bone marrow stem cells (BMSCs) cultured in this bioactive scaffold was similar to that in osteogenesis differentiation medium and more extensive in this bioactive scaffold compared to the scaffold without these three bioactive compounds
These results indicated that the Lysine diisocyanate (LDI) synthesized with this procedure was of adequate yield and purity for the preparation of LDI-based polymers with potential use in tissue engineering

Summary

Introduction

Bone defects are commonly caused by injury, trauma, infection or cancer and a large bone defect is difficult to repair. Bone tissue engineering provides an alternative to bone regeneration and most common models of engineering new tissue are based on seeding isolated cells on a three-dimensional scaffold followed by in vitro culture [1]. The properties of polyurethanes can be modified by changing the ratio of hard and soft segments and by varying chemical composition [2]. They can be strong elastomers or rigid plastics, and they can be processed using extrusion, injection molding, film blowing, solution dipping, and two-part liquid molding. Isocyanates are the fundamental starting materials for the synthesis of polyurethanes. Commercial isocyanates are toxic due to their degradation products such as aromatic diamines [8, 9]

Methods

Results

Conclusion