A Simple, Safe, and Effective Method for Preparing Autologous Bio-Based Fibrin Glue for Ophthalmic Use

Abstract

This study proposes a method to prepare autologous bio-based fibrin glue (FG) for use in ophthalmic surgery. FGs containing three fibrinogen concentrations and a thrombin concentrate were prepared using human blood from five donors (FG1: physiological fibrinogen concentration; FG2 and FG3: concentrated fibrinogen). The adhesion strength was tested, and the clinical safety and efficacy were studied in rabbit eyes in conjunctival surgery. A commercial FG was used as a control. From each donor, 2 mL of FG was prepared, containing 1 mL of 3.49 ± 0.78 (FG1), 17.74 ± 4.66 (FG2), or 47.46 ± 9.36 mg/mL (FG3) of fibrinogen and 1 mL of 2248.12 ± 604.20 UI/mL of thrombin. The average adhesion strength increased with the fibrinogen concentration, from 1.49 ± 0.39 kPa (FG1) to 3.14 ± 1.09 kPa (FG3). FG1 showed poor results when used for autograft adhesion. In contrast, the conjunctival autografts were successfully grafted using FG2 and FG3, revealing equivalent adhesion properties compared with commercial FG, but with less inflammation. In conclusion, FGs could be prepared on demand within minutes from small volumes of human blood, using a method that results in FGs which exhibit good adhesion capacity and are also safe and effective in a preclinical study.

Keywords: fibrin glue; ophthalmology; sealant; tissue adhesive; tissue glue.

Figure 1

Adhesion strength assay. (A) Samples of porcine skins glued with FGs or commercial FG, indicating its dimensions (5 cm length, 2.5 cm width, and 1 cm overlap) according to the ASTM manual F2255–05 [25]. (B) Adhesion strength test. ASTM: American Society for Testing and Materials; FG: bio-based fibrin glue.

Figure 2

Mean fibrinogen concentration (A) and thrombin activity (B) obtained in FG1, FG2, and FG3, and a statistical comparison with the commercial FG as a control. **: p-value < 0.01. Data are shown as the mean ± SD. FG: bio-based fibrin glue.

Figure 3

Mean adhesion strength obtained in FG1, FG2, and FG3 and a statistical comparison with the commercial FG as a control. *: p-value < 0.05. Data are shown as the mean ± SD. FG: bio-based fibrin glue.

Figure 4

Clinical evolution of bulbar conjunctiva autografts on a bare scleral bed transplanted using different FGs and the commercial FG. Arrows show the grafted area in the bulbar conjunctiva. FG: bio-based fibrin glue.

Figure 5

H&E and IL-6 immunofluorescence stains of a representative sample of each FG group. No inflammatory cells and no edema were observed in FG1, FG2, or FG3 samples. Commercial FG showed inflammatory cells and edema. Scale bars: 50 µm. FG: bio-based fibrin glue; IL-6: interleukin-6.