Objectives: The decellularization of non-autologous, biological implants allows a reduction of
the immune and inflammatory responses against donor tissue. To accelerate the autologous
in vivo recellularization of aortic prostheses for an enhanced biocompatibility, we
tested laminin surface coating in a standardized rat implantation model.
Methods: Decellularized rat aortic grafts (n = 28) were surface-coated with laminin (1 mg/mL, 24h) and implanted into the systemic
circulation of Wistar rats for 2 and 8 weeks (n = 9 per time point). Uncoated implants served as controls (n = 5 for each time point). Cellular repopulation of the implants was examined by scanning
electron microscopy (n = 10), histology and immunofluorescence (n = 18).
Results: Laminin coating was persistent for at least 8 weeks. After 2 weeks, no relevant re-colonization
of the intimal surface was observed. At 8 weeks, neoendothelialization was significantly
accelerated in the laminin group (p = 0.0048). Interestingly, the intima-to-media thickness ratio was significantly decreased
in the laminin group (p = 0.0149). Medial recellularization did not differ between both groups (p = 0.6370). Originating from the adventitial surface, α-smooth muscle actin-positive
invasion into the media was observed in both groups in a similar manner. In the laminin
group and in the control group, intima and media calcification occurred to the same
extent. In both groups, inflammatory cell markers (CD3 and CD68) proved negative.
Conclusion: Laminin coating of decellularized aortic grafts showed in vivo persistence for at
least 8 weeks. This treatment resulted in accelerated autologous recellularization
and reduced intima hyperplasia. In summary, laminin coating may be a promising approach
to improve the biocompatibility of tissue-engineered vascular implants.
