Abstract

Xenogeneic acellular collagen matrices represent a safe alternative to autologous soft tissue transplants in periodontology and implant dentistry. Here, we aimed to investigate the adsorption and release of growth factors from four porcine-derived collagen matrices using enzyme-linked immunosorbent assay. Non-crosslinked collagen matrix (NCM), crosslinked collagen matrix (CCM), dried acellular dermal matrix (DADM), and hydrated acellular dermal matrix (HADM) adsorbed each of the following growth factors, TGF-β1, FGF-2, PDGF-BB, GDF-5 and BMP-2, with an efficiency close to 100%. Growth factor release for a 13-day period was in the range of 10-50% of the adsorbed protein, except for the BMP-2 release that was in the range of 5-7%.

Generally, protein release occurred in two phases. Phase I was arbitrary defined by the highest release from the matrices, usually within 24 h. Phase II, spanning the period immediately after the peak release until day 13, corresponded to the delayed release of the growth factors from the deeper layers of the matrices. HADM showed significantly (P < 0.001) higher TGF-β1, FGF-2, and PDGF-BB release in phase II, compared to the rest of the matrices.

NCM exhibited significantly (P < 0.001) higher FGF-2 release in phase II, compared to CCM and DADM as well as a characteristic second peak in PDGF-BB release towards the middle of the tested period. In contrast to NCM and HADM, CCM and DADM showed a gradual and significantly higher release of GDF-5 in the second phase.

Several burst releases of BMP-2 were characteristic for all matrices. The efficient adsorption and sustained protein release in the first 13 days, and the kinetics seen for HADM, with a burst release within hours and high amount of released growth factor within a secondary phase, may be beneficial for the long-term tissue regeneration following reconstructive periodontal surgery.