Increasing the volume of vascularized tissue formation in engineered constructs: an experimental study in rats.
The authors have previously described a model of in vivo tissue generation based on an implanted, microsurgically created vessel loop in a plastic chamber (volume, 0.45 ml) containing a poly(DL-lactic-co-glycolic acid) (PLGA) scaffold. Tissue grew spontaneously in association with an intense angiogenic sprouting from the loop and almost filled the chamber, resulting in a mean amount of tissue in chambers of 0.23 g with no added matrix scaffold and 0.33 g of tissue in PLGA-filled chambers after 4 weeks of incubation. The aim of the present study was to investigate whether a greater volume of tissue could be generated when the same-size vessel loop was inserted into a larger (1.9 ml) chamber. In four groups of five rats, an arteriovenous shunt sandwiched between two disks of PLGA, used as a scaffold for structural support, was placed inside a large polycarbonate growth chamber. Tissue and PLGA weight and volume, as well as histological characteristics of the newly formed tissue, were assessed at 2, 4, 6, and 8 weeks. Tissue weight and volume showed a strong linear correlation. Tissue weight increased progressively from 0.13 +/- 0.04 g at 2 weeks to 0.57 +/- 0.06 g at 6 weeks (p < 0.0005). PLGA weight decreased progressively from 0.89 +/- 0.07 g at 2 weeks to 0.20 +/- 0.09 g at 8 weeks (p < 0.0005). Histological examination of the specimens confirmed increased tissue growth and maturation over time. It is concluded that larger quantities of tissue can be grown over a longer period of time by using larger-size growth chambers.
Hofer
Stefan O P
SO
Bernard O'Brien Institute of Microsurgery, University of Melbourne, St. Vincent's Hospital, 42 Fitzroy Street, Fitzroy, Victoria 3065, Australia. bobimsvh@svhm.org.au
Knight
Katherine M
KM
Cooper-White
Justin J
JJ
O'Connor
Andrea J
AJ
Perera
Jilska M
JM
Romeo-Meeuw
Rosalind
R
Penington
Anthony J
AJ
Knight
Kenneth R
KR
Morrison
Wayne A
WA
Messina
Aurora
A
D000818:Animals; D015194:Diffusion Chambers, Culture; D008297:Male; D018919:Neovascularization, Physiologic; D051381:Rats; D017207:Rats, Sprague-Dawley; D023822:Tissue Engineering / Q000379:methods