Biocompatible Interface-Modified Tissue Engineering Chamber Reduces Capsular Contracture and Enlarges Regenerated Adipose Tissue.

Adipose flap expansion using a tissue engineering chamber (TEC) presents a promising candidate for soft tissue regeneration by activating in situ adipose tissue regeneration. However, foreign body reaction (FBR) and capsular contracture caused by a silicone chamber limit large tissue reconstruction. Here, a hydrophilic and biodegradable film made of poly(ethylene glycol) diacrylate (PEG-da) with methacrylated gelatin (gelatin-MA) was presented between the host tissue and silicone chamber to tune the local wound and to prevent initiation of FBR. After a 60 day investigation, 6.1-fold-regenerated fat tissue was obtained from the PEG-gelatin group, whereas only 3-fold tissue was harvested from a silicone group. Histological staining demonstrated that the structure of the neo-formed adipose tissue in both groups was similar to mature adipose tissue. Noticeably, a more distinct and denser fibrous capsule was observed in the silicone group compared to the PEG-gelatin group. Immunohistochemistry of CD206 and TGF-β expression indicated less M2 macrophage infiltration and a minor inflammation reaction with PEG-gelatin assistance. Less collagen deposition and myofibroblast activation in the PEG-gelatin group were demonstrated via α-SMA and type I collagen staining. All these demonstrated that a biocompatible membrane supplement can attenuate capsule formation and contracture leading to a larger tissue regeneration through the TEC technique, which could lead to new perspectives to the relationship between materials-mattered FBR and tissue regeneration.