Comparison of physical and biological properties of CardioCel ® with commonly used bioscaffolds

OBJECTIVES Durability of bioscaffolds cross-linked with glutaraldehyde and used in cardiovascular surgery is limited by biomechanical instability, calcification and reduced biocompatibility. This study compares CardioCel ®, a bovine pericardial scaffold engineered via the ADAPT ® process to ensure optimized biostability and biocompatibility, with the commonly used bioscaffolds. METHODS Bovine pericardial scaffolds, cross-linked with 0.6% glutaraldehyde (XenoLogiX™, PeriGuard ®), dye-mediated photo-oxidized (PhotoFix™) and a non-crosslinked porcine scaffold (CorMatrix ®), were compared with CardioCel (decellularized, cross-linked with 0.05% monomeric glutaraldehyde, detoxified) by thermal stability and mechanical tests. Biocompatibility and calcification were assessed in a juvenile subcutaneous rat model at 6 and 12 weeks. RESULTS CardioCel displayed significantly higher (P < 0.01) cross-link stability (77.99 ± 0.64 °C) than CorMatrix (57.88 ± 0.22 °C) and PhotoFix (53.96 ± 0.41 °C). Tensile strength of CardioCel (8.31 ± 3.36 MPa) was comparable with XenoLogiX (11.00 ± 5.43 MPa, P = 0.734), PeriGuard (16.44 ± 6.69 MPa, P = 0.136), PhotoFix (7.10 ± 6.11, P = 0.399) and CorMatrix (9.75 ± 2.61, P = 0.204). XenoLogiX and PeriGuard recorded the highest Young's modulus (67.01 ± 30.36 vs 95.67 ± 45.91 MPa), while CardioCel (50.21 ± 19.92 MPa) was comparable with CorMatrix (36.78 ± 10.47 MPa, P = 0.204) and PhotoFix (33.50 ± 10.24, P = 0.399). CorMatrix displayed a significantly (P < 0.05) greater stiffness (4.74 ± 0.77 MPa) at 10% strain than PeriGuard (3.73 ± 1.79 MPa), PhotoFix (1.59 ± 0.40 MPa) and CardioCel (3.39 ± 0.83 MPa). Differences in extractable calcium did not reach significance; however, the inorganic phosphorus content of PhotoFix (21.3 ± 9.0 μg/mg) was higher than CardioCel (11.35 ± 0.76 μg/mg, P = 0.004) or PeriGuard (10.7 ± 2.18 μg/mg, P = 0.002) at 12 weeks. CardioCel underwent a typical mild host-graft response with fibroblast infiltration and remodelling. Foreign body reactions were visible in both XenoLogiX and PeriGuard, with isolated fibroblast infiltration. PhotoFix showed severe inflammation and 2 implants were completely degraded at 12 weeks. CONCLUSIONS CardioCel demonstrated optimized physical properties, minimal mineralization potential and superior biocompatibility. These results may benefit the long-term performance of this bioscaffold for cardiovascular surgery. The favourable characteristics of the comparator products were counterbalanced by less desirable features that may have negative implications on durability and performance when used in cardiovascular procedures.