Silk-based fibers and biomaterials for biomedical applications

The candidate will be responsible for the production and characterization of silk-based fibers and biomaterials for biomedical applications, including (1) natural sources such as silkworm and spider silk gut, and (2) regenerated and/or bioinspired fibers produced by straining flow spinning.

Main objective is the production of fibers with properties comparable to those of the natural material from either silk gut or by straining flow spinning. In particular, a minimum value of the work to fracture of 30 MJ/m3 will be considered for validating the spun fibers. Processing conditions will be varied in both cases in an attempt to modify the properties of the produced fibers.

Microstructural characterization of the high performance fibers will proceed by using X ray diffraction, infrared spectroscopy and atomic force microscopy, then retrieved data will be crosschecked with those of the mechanical characterization to establish general trends that clarify the origin of high performance in silk-based materials. Characterization will be complemented with the biological assessment of the fibers.

An initial in vitro assessment will include cell culture of different cell lineages (mesenchymal stem cells and MC3T3 pre-osteoblasts) with the two types of fibers. Upon discarding a possible toxic effect of the materials, the fibers will be implanted in a murine model to determine the biological response in vivo. Evaluation of the in vivo response will include both histological and functional analysis. The functional analysis will determine the type of tissue that grows around the implant, and should discard the possibility of chronic inflammation. The functional analysis will assess whether the animals recover full functionality upon implantation of the material.