Tissue engineered prefabricated vascularized flaps.
BACKGROUND.: Microvascular free tissue transfer has become increasingly popular in the reconstruction of head and neck defects, but it also has its disadvantages. Tissue engineering allows the generation of neo-tissue for implantation, but these tissues are often avascular. We propose to combine tissue-engineering techniques together with flap prefabrication techniques to generate a prefabricated vascularized soft tissue flap.


METHODS
Human dermal fibroblasts (HDFs) labeled with fluorescein diacetate were static seeded onto polylactic-co-glycolic acid-collagen (PLGA-c) mesh. Controls were plain PLGA-c mesh. The femoral artery and vein of the nude rat was ligated and used as a vascular carrier for the constructs. After 4 weeks of implantation, the constructs were assessed by gross morphology, routine histology, Masson trichrome, and cell viability determined by green fluorescence.


RESULTS
All the constructs maintained their initial shape and dimensions. Angiogenesis was evident in all the constructs with neo-capillary formation within the PLGA-c mesh seen. HDFs proliferated and filled the interyarn spaces of the PLGA-c mesh, while unseeded PLGA-c mesh remained relatively acellular. Cell tracer study indicated that the seeded HDFs remained viable and closely associated to remaining PLGA-c fibers. Collagen formation was more abundant in the constructs seeded with HDFs.


CONCLUSIONS
PLGA-c, enveloped by a cell sheet composed of fibroblasts, can serve as a suitable scaffold for generation of a soft tissue flap. A ligated arteriovenous pedicle can serve as a vascular carrier for the generation of a tissue engineered vascularized flap.
Kian Kwan Oo
Kenneth
K
Department of Otolaryngology, Head and Neck Surgery, National University of Singapore, Singapore, Singapore. kkkwco@yahoo.com
Chen Ong
Wei
W
Hui Chi Ang
Annette
A
Hutmacher
Dietmar W
DW
Kim Siang Tan
Luke
L
D000818:Animals; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis; D005347:Fibroblasts / Q000502:physiology*; D019344:Lactic Acid; D018919:Neovascularization, Physiologic; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D051381:Rats; D011923:Rats, Nude; D012867:Skin / Q000166:cytology*; D017768:Skin, Artificial; D013524:Surgical Flaps / Q000098:blood supply*; D013526:Surgical Mesh; D023822:Tissue Engineering / Q000379:methods*; D014654:Vascular Patency
D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D003094:Collagen