Evidence Hub

Nucleation and growth of mineralized bone matrix on silk-hydroxyapatite composite scaffolds

Bhumiratana S, Grayson WL, Castaneda A, Rockwood DN, Gil ES, Kaplan DL, Vunjak-Novakovic G

Biomaterials, 2011

Abstract

We describe a composite hydroxyapatite (HA)-silk fibroin scaffold designed to induce and support the formation of mineralized bone matrix by human mesenchymal stem cells (hMSCs) in the absence of osteogenic growth factors. Porous three-dimensional silk scaffolds were extensively used in our previous work for bone tissue engineering and showed excellent biodegradability and biocompatibility. However, silk is not an osteogenic material and has a compressive stiffness significantly lower than that of native bone. In the present study, we explored the incorporation of silk sponge matrices with HA (bone mineral) micro-particles to generate highly osteogenic composite scaffolds capable of inducing the in vitro formation of tissue-engineered bone. Different amounts of HA were embedded in silk sponges at volume fractions of 0%, 1.6%, 3.1% and 4.6% to enhance the osteoconductive activity and mechanical properties of the scaffolds. The cultivation of hMSCs in the silk/HA composite scaffolds under perfusion conditions resulted in the formation of bone-like structures and an increase in the equilibrium Young's modulus (up to 4-fold or 8-fold over 5 or 10 weeks of cultivation, respectively) in a manner that correlated with the initial HA content. The enhancement in mechanical properties was associated with the development of the structural connectivity of engineered bone matrix. Collectively, the data suggest two mechanisms by which the incorporated HA enhanced the formation of tissue…

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free