Enhanced vascular biocompatibility of decellularized xeno-/allogeneic matrices in a rodent model

Abstract

Glutaraldehyde preservation is the gold standard for cardiovascular biological prosthesis. However, secondary calcifications and the absence of tissue growth remain major limitations. Our study assessed in vitro and in vivo the biocompatibility of human (fascia lata, pericardium) and porcine tissues (pericardium, peritoneum) treated with a physicochemical procedure for decellularization and non-conventional pathogens inactivation. Biopsies were performed before and after treatment to assess decellularization (HE/Dapi staining/DNA quantification/MHC I/alpha gal immunostaining) and mechanical integrity. Forty-five rats received an abdominal aortic patch of native cryopreserved tissues (n = 20), treated tissues (n = 20) or glutaraldehyde-preserved bovine pericardium (GBP, control, n = 5). Grafts were explanted at 4 weeks and processed for HE/von Kossa staining and immunohistochemistries for lymphocytes (CD3)/macrophages (CD68) histomorphometry. 95% of decellularization was obtained for all tissues except for fascia lata (75%). Mechanical properties were slightly altered. In the in vivo model, a significant increase of CD3 and CD68 infiltrations was found in native and control implants in comparison with decellularized tissues (p < 0.05). Calcifications were found in 3 controls. Decellularized tissues were recolonized. GBP showed the most inflammatory response. This physicochemical treatment improves the biocompatibility of selected xeno/allogeneic tissues in comparison with their respective native cryopreserved tissues and with GBP. Incomplete decellularization is associated with a significantly higher inflammatory response. Our treatment is a promising tool in the field of tissue decellularization and tissue banking.

Enhanced Vascular Biocompatibility and Remodeling of Decellularized and Secured Xenogeneic/Allogeneic Matrices in a Porcine Model

“…As previously described [8], HP and HFL were procured according to the common standards of the European Association of Musculoskeletal Transplantation (EAMST, Vienna, 1997). A systematic screening of medical history and serological testing (for HIV-1 and HIV-2, HTLV-1, hepatitis B and C, and syphilis) were performed before harvesting and treatment.…”

“…The nontreated tissues were named NHFL, NHP, NPPt, and NBP for native HFL, HP, PPt, and BP. GBP was purchased and served as control [8]. …”

“…HE, Masson’s trichrome, and von Kossa colorations were used to assess inflammation, tissue remodeling/cell infiltration, structure, and calcifications, respectively. Immunohistochemistry for CD3 and CD68 was performed using a Ventana Benchmark XT machine (Roche®, USA) to assess inflammatory reaction as previously described [8]. The CD68 is particularly useful as a marker for the various cells of the macrophage lineage, including monocytes, histiocytes, giant cells, Kupffer cells.…”

“…But currently, clinical results are not optimal, and nondecellularization/glutaraldehyde fixation of biological xenografts for cardiovascular applications is still widely used in the biomedical industry [6, 7]. In a previous study, we reported the efficacy of a particular physicochemical treatment to ensure tissue decellularization (cell DNA and antigen removal while maintaining mechanical properties) and to improve in vivo biocompatibility in a vascular rodent model of xeno-/allogeneic tissues (porcine peritoneum [PPt], human pericardium [HP]/fascia lata [HFL]) in comparison to native and a largely used glutaraldehyde-fixed bovine pericardium (GBP) in cardiovascular surgery [8]. Treated HFL served as control since it showed good clinical results in various surgeries with optimal graft integration and remodeling [9, 10], while PPt was assessed as an alternative to HP since xenogeneic tissues are available in larger quantity.…”

“…In contrast to most common decellularization processes, the treatment has the advantage of securing the grafts by conventional and nonconventional pathogen inactivation [8, 11]. …”