Analysis of neovascularization of PEGT/PBT-copolymer dermis substitutes in balb/c-mice.
BACKGROUND
A fundamental prerequisite for using degradable synthetic biopolymers as composite skin substitutes is the ability to establish vascular tissue. PEGT/PBT block-copolymer matrices have previously been shown as a favorable dermal substitute. In this study, quantitative data on neovascularization of PEGT/PBT block-copolymer matrices are presented.


METHODS
PEGT/PBT-block-copolymer discs of three different pore diameters (1: < 75 microm, 2: 75-212 microm, 3: 250-300 microm) were implanted into dorsal skinfold chambers of balb/c mice. Histological sections were evaluated 7, 14, and 21 days post implantation by light and scanning electron microscopy. Blood vessel analysis was performed by means of digital image analysis (n = 288) of hematoxylin/eosin stained sections within apical (AOF) and basal (BOF) observation fields of the matrices.


RESULTS
Twenty-one days after implantation the density of blood vessels within the BOF of the scaffolds with a pore size of 75-212 and 250-300 microm were 4.6 +/- 0.45 and 5.8 +/- 0.62 (mean +/- S.E.M.; blood vessel profiles (BVF)), respectively. In <75 microm scaffolds, smaller numbers of BVF were found (4.2 +/- 0.39). In contrast, the evaluation within the AOF revealed significantly higher numbers of BVF in 75-212 microm group (3.5 +/- 0.49) and 250-300 microm group (4.5 +/- 0.66) as compared to the < 75 microm group (2.3 +/- 0.48).


CONCLUSIONS
There is evidence that the three-dimensional structure of PEGT/PBT-block-copolymer (pore size structure) influences neovascularization. The porous structures of copolymer matrices with adequate interconnection of pores (pore sizes of 75-212 and 250-300 microm) are characterized by faster ingrowth of vascular tissue.
Ring
Andrej
A
Department of Plastic and Hand Surgery, Burn Center, Department of Pathology, University Hospital Bergmannsheil, Ruhr University Bochum, Buerkle-de-la-Camp Platz 1, 44789 Bochum, Germany.
Langer
Stefan
S
Homann
Heinz Herbert
HH
Kuhnen
Cornelius
C
Schmitz
Inge
I
Steinau
Hans Ulrich
HU
Drücke
Daniel
D
D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use; D002056:Burns / Q000628:therapy*; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D018919:Neovascularization, Physiologic; D011091:Polyesters / Q000627:therapeutic use*; D011092:Polyethylene Glycols / Q000627:therapeutic use*; D012867:Skin / Q000098:blood supply*; D012879:Skin Physiological Phenomena; D017768:Skin, Artificial; D023822:Tissue Engineering / Q000379:methods*; D016896:Treatment Outcome
D001672:Biocompatible Materials; C493255:PEGT-PBT copolymer; D011091:Polyesters; D011092:Polyethylene Glycols