Biomimetic and osteogenic 3D silk fibroin composite scaffolds with nano MgO and mineralized hydroxyapatite for bone regeneration

Abstract

Artificial bioactive materials have received increasing attention worldwide in clinical orthopedics to repair bone defects that are caused by trauma, infections or tumors, especially dedicated to the multifunctional composite effect of materials. In this study, a weakly alkaline, biomimetic and osteogenic, three-dimensional composite scaffold (3DS) with hydroxyapatite (HAp) and nano magnesium oxide (MgO) embedded in fiber (F) of silkworm cocoon and silk fibroin (SF) is evaluated comprehensively for its bone repair potential in vivo and in vitro experiments, particularly focusing on the combined effect between HAp and MgO. Magnesium ions (Mg2+) has long been proven to promote bone tissue regeneration, and HAp is provided with osteoconductive properties. Interestingly, the weak alkaline microenvironment from MgO may also be crucial to promote Sprague-Dawley (SD) rat bone mesenchymal stem cells (BMSCs) proliferation, osteogenic differentiation and alkaline phosphatase (ALP) activities. This SF/F/HAp/nano MgO (SFFHM) 3DS with superior biocompatibility and biodegradability has better mechanical properties, BMSCs proliferation ability, osteogenic activity and differentiation potential compared with the scaffolds adding HAp or MgO alone or neither. Similarly, corresponding meaningful results are also demonstrated in a model of distal lateral femoral defect in SD rat. Therefore, we provide a promising 3D composite scaffold for promoting bone regeneration applications in bone tissue engineering.

Mutual chemical effect of autograft and octacalcium phosphate implantation on enhancing intramembranous bone regeneration

“…Apo E and C3 have been reported to have functions in osteoblast differentiation [ 85 ] and in osteoclastic cells recruitment [ 86 ], respectively, suggesting that OCP has a positive role not only for host bone-related cells but also for osteoblastic and osteoclastic cells associated with autologous bone through these adsorbed proteins. Other studies have shown that soluble amorphous calcium phosphate (ACP) [ 87 ], reactive calcium phosphate cements [ 88 ] and mineralized HA crystals together with magnesium oxide (MgO) [ 89 ] display significant effects on increasing osteogenic cellular activities. Although there is no direct comparative evidence on the performance from these materials to the present OCP, calcium phosphate materials, including OCP, may commonly stimulate the osteogenic cells through their chemical properties.…”

Recent Trends in the Development of Bone Regenerative Biomaterials

“…In general, there are five therapeutic targets in bone regeneration, such as vascularization, growth factors, osteogenesis, osteoconductive scaffolds, and mechanical environment (Zhang et al, 2018). Wu et al (2020) prepared a biomimetic and osteogenic composite scaffold (3DS) with HAp and nano magnesium oxide (MgO) embedded in fiber (F) of silkworm cocoon and SF for bone regeneration. On account of the combined effect of HAP and MgO, magnesium ions (Mg 2+ ) promoted bone mesenchymal stem cell (BMSC) proliferation, osteogenic differentiation, and alkaline phosphatase (ALP) activities while HAp provided outstanding osteoconductive properties, which were used as potential 3D composite scaffolds for bone regeneration applications (Wu et al, 2020).…”

Biomaterials for bone regeneration: an orthopedic and dentistry overview

“…Magnesium (Mg-), iron (Fe), zinc, and their alloys have been the most studied. Wu et al ( 18 ) proposed a three-dimensional composite scaffold with HA and magnesium oxide embedded in fiber of silkworm cocoon and silk fibroin. The addition of 1 wt.% MgO led to the release of magnesium ions, which created a weak alkaline environment that improved the proliferation and osteogenic differentiation of bone marrow stem cells (BMSCs ) in vitro , as well as promoted in vivo bone formation.…”