[An experimental study on the difference of the antigenicity of xenogenic acellular dermal matrix]

To investigate the difference of the antigenicity of xenogenic acellular dermal matrix (ADM) implants prepared by different methods.

The split-thickness skin sheet from swine was processed by trypsin and Triton X-100 to make xeno-ADM. Twenty-five Japanese white rabbits were divided into 5 groups, i.e. xeno-ADM(1) (conjugated with glutaraldehyde), xeno-ADM(2) (conjugated with network) and xeno-ADM(3) (no conjugation, as control), in which the ADMs were and xeno-ADM(4) (conjugated) and allo-ADM (no conjugated as control), in which the ADMs were embedded into the subcutaneous place of rabbit ear and back after that the rabbits were pre-sensitized by xeno-ADM soluble protein antigen injections. The titers of anti ADMs antibody in rabbit serum were monitored during 2 - 32 post-operative weeks and the histological changes of the embedded ADMs were observed grossly and microscopically.

The serum titers of anti-xeno-ADM in xeno-ADM(4) group was the highest. Whereas regardless of the sensitizing effects, the titers in all groups ranged as follows: xeno-ADM(3) > xeno-ADM(2) > xeno-ADM(1) (P < 0.05 - 0.01). About 40% serum samples in allo-ADM group exhibited positive anti-allo-ADM protein antibodies. Histologically, Evident and lasting inflammatory reaction could be found in the xeno-ADM grafting sites, which was much stronger than that in allo-ADM group. The degradation and absorption gradient of ADM was ranked as follow: xeno-ADM(3) > xeno-ADM(2) > xeno-ADM(4) > xeno-ADM(1) > Allo-ADM. Foreign body megalocytic reaction might evoke in the surrounding of conjugated ADM.

The immunogenicity in xeno-ADM was stronger than that in allo-ADM, which could induce the host to develop immune reaction restricted by IgG. Large sheets of degenerated ADM implants could lower down the antigen-antibody reaction and ameliorate the structural destroying and degeneration absorption of ADM induced by inflammatory immune reaction.