Engineering of vascularized adipose constructs

Abstract

Adipose tissue engineering offers a promising alternative to the current surgical techniques for the treatment of soft tissue defects. It is a challenge to find the appropriate scaffold that not only represents a suitable environment for cells but also allows fabrication of customized tissue constructs, particularly in breast surgery. We investigated two different scaffolds for their potential use in adipose tissue regeneration. Sponge-like polyurethane scaffolds were prepared by mold casting with methylal as foaming agent, whereas polycaprolactone scaffolds with highly regular stacked-fiber architecture were fabricated with fused deposition modeling. Both scaffold types were seeded with human adipose tissue-derived precursor cells, cultured and implanted in nude mice using a femoral arteriovenous flow-through vessel loop for angiogenesis. In vitro, cells attached to both scaffolds and differentiated into adipocytes. In vivo, angiogenesis and adipose tissue formation were observed throughout both constructs after 2 and 4 weeks, with angiogenesis being comparable in seeded and unseeded constructs. Fibrous tissue formation and adipogenesis were more pronounced on polyurethane foam scaffolds than on polycaprolactone prototyped scaffolds. In conclusion, both scaffold designs can be effectively used for adipose tissue engineering.

Macrophage Phenotype in Response to Implanted Synthetic Scaffolds: An Immunohistochemical Study in the Rat

“…These findings are consistent with other studies considering in vivo tissue responses to PCL, where absent or minimal macrophage responses were reported within subcutaneous scaffolds over a 6-month period in rabbits [Lam et al, 2009] and in craniotomy defects in rats after 28 days [Byers et al, 2006]. Other studies in mice reported only mild inflammatory responses to PCL in a vessel loop model at 2 and 4 weeks [Wiggenhauser et al, 2012] and subcutaneously at 1 and 3 months [Seyednejad et al, 2012]. Only one study [Baker et al, 2011] characterised the macrophage response using immunohistochemistry, and in contrast to our findings in a similar rat model the presence of surface-adherent CD68+ macrophages was noted in porous PCL implants that had been chemically cross-linked.…”

Adipose Tissue Engineering in Three-Dimensional Levitation Tissue Culture System Based on Magnetic Nanoparticles

“…51 It has been shown that tissues engineered ex vivo based on scaffolds can become vascularized upon implantation into a host. 40 It was also reported that grafting of human ASC grown in spheroids is similarly followed by in vivo angiogenesis. 52 Interestingly, a recent study demonstrated that scaffold-free spheroids preserve multilineage potential of MSC.…”

“…39 More rigid, sponge-like scaffolds made from materials such as hydroxyapatite, or synthetic organic polymers casted using foaming agents, have also been introduced. 40,41 While artificial matrices are often used in tissue modeling, the relevance of tissue composition achieved with their help to in vivo settings has remained questionable. Recently, matrix scaffolds based on decellularized native tissues have gained popularity.…”

Vascularization of engineered cartilage constructs in a mouse model

“…Cronin et al (2004) placed a split silicone tube around an arteriovenous pedicle in the mouse groin, thus inducing the formation of newly vascularized tissue. Wiggenhauser et al (2012) used the same mouse model as presented here to vascularize adipose tissue. Both Cronin et al Fig.…”