Proliferation of human fibroblasts in vitro after exposure to orbital implants

Background: Porous orbital implants allow fibrovascular ingrowth and integr ation with the extraocular muscles. The available implants have different s tructural characteristics, which may influence orbital response. We studied the proliferation of orbital fibroblasts in vitro after exposure to four d ifferent orbital implants. Methods: Four orbital implant biomaterials were studied: hydroxyapatite (Bi o-Eye), synthetic hydroxyapatite, porous polyethylene (Medpor) (pore sizes 150 mum and 400 mum) and aluminium oxide (Bioceramic implant). Human fibrob lasts obtained from orbital fat at the time of elective blepharoplasty were cultured and then exposed to the individual implants. Cell growth was asse ssed with immunocytochemical analysis using bromodeoxyuridine, a thymidine analogue. After DNA denaturation, the cells were washed, incubated with sec ondary antibody and visualized. Results: The fibroblasts growing on the Bio-Eye, synthetic hydroxyapatite, and 150-mum and 400-mum Medpor implants all had debris associated with them . The Bioceramic implant was free of this debris. The Bioceramic implant an d the 150-mum Medpor implant had the greatest number of fibroblasts on the coverslips. Interpretation: The proliferation of fibroblasts, as determined by visualiz ation of actively dividing cells with bromodeoxyuridine, differed on the va rious implants studied. The lack of debris associated with the Bioceramic i mplant may be related to the crystalline structure of the implant.