**2. The application of silk fibroin in tissue engineering**

It is known to all that the application of silk production as un-absorb suture has many years of history. Along with the progress of tissue engineering techniques, scientists can extract natural polymeric materials- fibroin from silk and make it into different forms to fit various needs of tissue engineering[1]. Vitro studies show silk fibroin is biodegradable. The speed and degree of degradation can be adjusted through changing physicochemical property[2-4]. The product of degradation is mainly free amino acid and has no toxic sideeffect on tissue.

Silk fibroin can be easily made into different forms to serve for various needs such as membrane, gelatum, knitting scaffold, porous scaffold and electrospinning scaffold. Therefore, it has been gradually utilized in various medical field such as drug delivery[5,6], nerve regeneration[7-9], dermis healing[10], artificial ligament repair[11,12], bone or cartilage healing[13.14], vascular tissue engineering[15,16], otology application[17] and so on.

A Preliminary In Vivo Study on the Histocompatibility of Silk Fibroin 417

Fig. 2. Thin connective tissue wrap could be found on the scaffold, and the inflammatory

number inflammatory reaction fibrous

2 2 slight yes no 4 2 slight yes no 6 2 slight yes no 8 2 slight yes no

**The fourth week**: There is few parts with eosinophilic staining inside the material disappears 4 weeks after operation, which shows crumbling phenomenon, while it's general structure remains(figure 5). Fibroblasts grow along the surface of the scaffold or into the pores. There are lymphocytes and macrophages infiltrate. Vessel hyperplasia is visible,

encapsulation

granulation formation

Fig. 1. The wound healed up well while taking samples

reaction surrounding the tissue was slight.

Time(week) Section

Table 1. general observation
