Comparison of four methods for generating decellularized equine synovial extracellular matrix

OBJECTIVE To evaluate 4 methods for generating decellularized equine synovial extracellular matrix. SAMPLE Villous synovium harvested from the femoropatellar and medial femorotibial joints of 4 healthy adult horses < 7 years of age. Synovial samples were frozen (-80°C) until used. PROCEDURES Synovial samples were thawed and left untreated (control) or decellularized with 1 of 4 methods (15 samples/horse/method): incubation in 0.1% peracetic acid (PAA), incubation in 0.1% PAA twice, incubation in 1% Triton X-100 followed by incubation in DNase, and incubation in 2M NaCl followed by incubation in DNase. Control and decellularized samples were examined for residual cells, villous integrity, and collagen structure and integrity by means of histologic examination and scanning electron microscopy; cell viability was evaluated by means of culture and exclusion staining. Decellularization efficiency was assessed by testing for DNA content and DNA fragment size. RESULTS Incubation in PAA once preserved the synovial villous architecture, but resulted in high DNA content and retention of large (> 25,000 base pair) DNA fragments. Incubation in Triton and incubation in NaCl resulted in low DNA content and short (< 200 base pair) DNA fragments, but destroyed the synovial villous architecture. Incubation in PAA twice resulted in low DNA content and short DNA fragments while retaining the synovial villous architecture. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that of the methods evaluated, incubation in 0.1% PAA twice was the best method for generating decellularized equine synovial extracellular matrix.