Influence of Laminin Coating on the Autologous In Vivo Recellularization of Decellularized Vascular Protheses

Abstract

Decellularization of non-autologous biological implants reduces the immune response against foreign tissue. Striving for in vivo repopulation of aortic prostheses with autologous cells, thereby improving the graft biocompatibility, we examined surface coating with laminin in a standardized rat implantation model. Detergent-decellularized aortic grafts from donor rats (n = 37) were coated with laminin and systemically implanted into Wistar rats. Uncoated implants served as controls. Implant re-colonization and remodeling were examined by scanning electron microscopy (n = 10), histology and immunohistology (n = 18). Laminin coating persisted over eight weeks. Two weeks after implantation, no relevant neoendothelium formation was observed, whereas it was covering the whole grafts after eight weeks, with a significant acceleration in the laminin group (p = 0.0048). Remarkably, the intima-to-media ratio, indicating adverse hyperplasia, was significantly diminished in the laminin group (p = 0.0149). No intergroup difference was detected in terms of medial recellularization (p = 0.2577). Alpha-smooth muscle actin-positive cells originating from the adventitial surface invaded the media in both groups to a similar extent. The amount of calcifying hydroxyapatite deposition in the intima and the media did not differ between the groups. Inflammatory cell markers (CD3 and CD68) proved negative in coated as well as uncoated decellularized implants. The coating of decellularized aortic implants with bioactive laminin caused an acceleration of the autologous recellularization and a reduction of the intima hyperplasia. Thereby, laminin coating seems to be a promising strategy to enhance the biocompatibility of tissue-engineered vascular implants.

Laminin-Modified Dental Pulp Extracellular Matrix for Dental Pulp Regeneration

“…After decellularization, laminins at the BM of vascular structures were preserved but lost at the place of the odontoblast layer in DPEM (Figure 5C: DPEM), consistent with the published reports (Chen et al, 2015a). Alexa Fluor 488-coupled laminin coating, a continuous, bright green fluorescence, was presented along the surface of laminin-modified DPEM (Figure 5C: DPEM/LN), meaning the method of laminin coating referred to previous reports (Toshmatova et al, 2019) would be feasible to the fabrication of laminin-modified DPEM.…”

“…The fluorescence of laminin still could be detected on the surface of the scaffold even after being seeded and cultured in vitro for 1 week ( Figure 5C ), showing the good persistence of laminin coating. Payam Akhyari et al demonstrated the physical coating of laminin could persist on decellularized grafts for at least 8 weeks in vivo ( Toshmatova et al, 2019 ). Meanwhile, SEM results showed DPSCs presented multilayer growth on the surface of the laminin-coated DPEM ( Figure 5D ).…”

Characterization of Laminins in Healthy Human Aortic Valves and a Modified Decellularized Rat Scaffold

“…Indeed, laminin coating, although of an undefined isoform, has been shown to promote endothelialization while decreasing intimal hyperplasia in aortic grafts in vivo . 6 On the other hand, the α5-containing LN-511 has been shown to be important in the shear stress response of resistance arteries 44 and may be of similar importance in heart valves during the cardiac cycle. The β-chain is also significant in endothelial BMs as an isoform switch from LN-421 to LN-411 may lead to decreased adhesion and increased endothelial-to-mesenchymal transition.…”

“…2 The ideal heart valve replacement is considered to be an offthe-shelf valve that does not exert an immune response and has the capacity to grow and be repopulated by living cells. Therefore, tissue-engineered heart valves, both decellularized and in vitro-produced scaffolds, have been developed and extensively studied in animal models, [3][4][5][6][7][8][9] and decellularized aortic valve allografts have even reached clinical trials. 10,11 Although initial studies have been favorable, tissue-engineered heart valves suffer from structural deterioration similar to conventional allografts and may even be associated with a higher reoperation rate.…”

Vascular Tissue Engineering: Polymers and Methodologies for Small Caliber Vascular Grafts

“…(B) Macroscopic appearance and (C) SEM image of decellularized rat aorta. The image is adapted from a report by Sugimura et al ( 56 ) and Toshmatova et al ( 57 ), respectively.…”