Acellular Dermal Matrix Susceptibility to Collagen Digestion: Effect on Mechanics and Host Response

Abstract

Various tissue origins and manufacturing processes can differentially affect the retention of native properties of acellular dermal matrices (ADMs); however, comparative studies are limited. Head-to-head comparisons between different configurations of porcine-derived Strattice (Allergan Aesthetics, an AbbVie Company, Irvine, CA) and bovine-derived SurgiMend (Integra LifeSciences, Billerica, MA) ADMs were performed to evaluate mechanical integrity and host tissue biologic response. Thermodynamic profile and morphology, which affect retention of mechanical strength, were evaluated through differential scanning calorimetry, scanning electron microscopy, and histology. Mechanical strength was assessed through tensile testing following collagenase exposure in vitro and following subcutaneous implantation in a rodent model. Host biologic response was evaluated through histopathology. Compared with respective native tissues, reductions in onset melting temperature following tissue processing were smaller for Strattice Firm versus SurgiMend 1.0 (Δ0.79°C vs. Δ5.77°C), Strattice Extra Thick versus SurgiMend 3.0 (Δ1.57°C vs. Δ4.79°C), and Strattice Perforated versus SurgiMend Microperforated (Δ1.18°C vs. Δ7.76°C), with similar trends for peak melting temperature. Strattice maintained native dermal architecture versus compacted collagen with process-induced interstices observed for SurgiMend. Strattice Firm, Extra Thick, and Perforated retained 33.44%, 65.65%, and 17.20% of initial strength after 48 h exposure to excess collagenase, while the SurgiMend ADMs were completely digested by 48 h. At 6 weeks postimplantation, both Strattice and SurgiMend showed minimal inflammatory response, but greater fibroblast repopulation was evident for Strattice. Strattice Firm had higher maximum load (145.85 ± 33.05 N/cm vs. 24.29 ± 12.35 N/cm, p ≤ 0.01), maximum stress (8.20 ± 1.91 MPa vs. 2.24 ± 1.27 Mpa, p ≤ 0.01), and stiffness (7491.00 ± 1981.32 N/cm vs. 737.56 ± 292.55 N/cm, p ≤ 0.01) than SurgiMend 1.0. Strattice Extra Thick had lower maximum load (198.54 ± 58.79 N/cm vs. 303.08 ± 76.76 N/cm, p < 0.05) than SurgiMend 3.0, but similar maximum stress (6.96 ± 1.78 Mpa vs. 8.73 ± 2.15 Mpa) and stiffness (13386.11 ± 3123.28 N/cm vs. 9389.02 ± 4860.67 N/cm). Strattice Perforated had higher maximum load (72.65 ± 41.44 N/cm vs. 10.23 ± 4.67 N/cm, p < 0.05) and maximum stress (4.08 ± 2.08 Mpa vs. 0.44 ± 0.19 p < 0.05) than SurgiMend Microperforated. Maximum load retention rates following implantation were higher for Strattice Firm versus SurgiMend 1.0 (37.85% vs. 8.03%), Strattice Extra Thick versus SurgiMend 3.0 (45.03% vs. 37.80%), and Strattice Perforated versus SurgiMend Microperforated (28.04% vs. 6.21%). Similar results were obtained for maximum stress and stiffness. In conclusion, Strattice retained greater mechanical strength in vitro and in vivo, while exhibiting greater fibroblast cell infiltration. Impact statement Acellular dermal matrix (ADM)-derived surgical meshes are used in abdominal wall reconstruction procedures, such as hernia repair. Comparative studies evaluating the mechanical properties of ADMs and how they integrate with host tissue are essential because these properties impact performance in a clinical setting. This study compared the maintenance of mechanical integrity and host tissue biologic response of two commercially available ADMs, Strattice and SurgiMend, using in vitro and in vivo techniques. A better understanding of the properties of ADMs is expected to impact mesh selection and help to minimize the incidence of herniation recurrence and need for revisional surgery.

Keywords: acellular dermal matrix; biomechanics; in vitro degradation; regeneration; rodent model; surgical meshes.