Biomedical Engineering Reference
In-Depth Information
Furthermore, nonwoven P3HB patches were effectively tested in sheep for
cardiovascular repair in low pressure systems, such as for closure of an atrial
septal defect [144] or as transannular patch in the right ventricular outflow
tract [145]. There were no signs of aneurysm formation or calcification. Inter-
estingly, no preseeding with vascular cells was necessary in these experiments
because the high mechanical strength and slow degradation of the polymer
prevented any dilatation of the regenerating tissue.
Gastrointestinal Patches
Resorbable P3HB patches for the gastrointestinal tract have been developed
to cover large open lesions if closure by conventional surgical techniques with
sutures or clips is impossible. These asymmetric patches were designed to
have a porous surface facing the bowel defect to support tissue regeneration,
and a smooth surface to prevent adhesions to the surrounding gut (Fig. 12).
Fig. 12 a
P3HB/at-P3HB asymmetric patches [17] (reprinted by permission of Wiley)
and
b
P3HB film/textile composite patches (Institute of Polymer Research, Dresden, Ger-
many) with porous surface to support tissue regeneration and smooth surface to prevent
adherence to surrounding organs
