Bio-functionalized titanium surfaces with modified silk fibroin carrying titanium binding motif to enhance the ossific differentiation of MC3T3-E1

Silk fibroin (SF) from Bombyx mori has superior properties as both a textile and a biomaterial, and has been used to functionalize the surfaces of various medical inorganic materials including titanium (Ti). In this study, we endowed SF with reversible binding ability to Ti by embedding a titanium binding motif (minTBP-1 and RKLPDA). Artificial SF proteins were first created by conjugating gene cassettes for SF motif (AGSGAG) and minTBP-1 motif with different ratios, which have been shown to bind reversibly to Ti surfaces in quartz crystal microbalance analyses. Based on these results, the functionalized SF (TiBP-SF) containing the designed peptide [TS[(AGSGAG)(3)AS](2)RKLPDAS](8) was prepared from the cocoon of transgenic B. mori, which accelerates the ossific differentiation of MC3T3-E1 cells when coated on titanium substrates. Thus, TiBP-SF presents an alternative for endowing the surfaces of titanium materials with osseointegration functionality, which would allow the exploration of potential applications in the medical field.

Automated summary

In this study, silk fibroin (SF) from Bombyx mori was endowed with reversible binding ability to titanium surfaces by embedding a titanium binding motif. The functionalized SF (TiBP-SF) can accelerate the differentiation of bone cells, providing a new method for endowing titanium materials with osseointegration functionality in potential medical applications.