Immunogenicity of the fish scale-derived collagen matrix for corneal reconstruction

Abstract

 

Purpose

 

A transparent, naturally-occurring, easily-obtainable fish scale-derived collagen type I matrix (FSCM) has been developed for reconstructing the cornea, demonstrating good cellular repopulation in vitro. Here we investigated the in vivo immunogenicity of this matrix in a non-immune privileged site in rats.

 

Methods

 

Male Fischer 344/DuCrl albino rats were divided into three equal groups, which received a subcutaneous implant of 1. either the FSCM, or 2. a commercial available collagen type I matrix (Ologen®) used in trabeculectomy surgery, or 3. underwent sham surgery. The animals were sacrificed at 7, 42 or 77 days postoperatively. Two additional groups with an FSCM or Ologen implant received a second matrix in the contra-lateral flank at 21 days postoperative and were sacrificed after 7 additional days. Aside standard haematoxylin and eosin staining, immunohistochemistry was performed for each group (n=3) to identify the immune infiltrate with antibodies against granulocytes (MPO), macrophages (ED-1), lymphocytes (CD3), and immunoglobulins (IgG).

 

Results

 

The infiltrate diminished over time from moderate in the acute phase, dominated by granulocytes and macrophages, to minimal in the chronic phase, dominated by lymphocytes. There was no significant difference in the amount of infiltrate between the FSCM and the two control groups (Ologen® and sham) after 7, 42 and 77 days postoperative. There was no indication of sensitization after the second implantation of either the FSCM or Ologen®.

 

Conclusions

 

The fish scale-derived collagen matrix for corneal reconstruction is not eliciting an unwanted immune reaction.

 

 

Haemotoxylin-eosin staining of the FSCM at 77 days follow-up, showing almost complete absence of infiltrating cells

 

Keywords: 575 keratoprostheses • 557 inflammation • 554 immunohistochemistry