Research on the effect of biological glue on augmenting the viscosity of tissue engineering retinal nerve scaffolds

Objective To evaluate the adhesion effect of tissue engineering retinal nerve scaffolds modified with biological glue. Methods Experimental study. To fabricate a biological glue by blending laminin, collagen Ⅳ, entactin and HSPG2 with phosphate-buffered saline (PBS) buffer solution, scaffolds were then modified with the biological glue of various concentration levels (10 μl/cm2, 20 μl/cm2, 30 μl/cm2 and 40 μl/cm2). The effects of various concentration levels glue on inducing scaffold adhesion were analyzed after 24 h. Cell count method and CCK-8 kit were used to assess the effects of biological glue on cell growth and toxicity. Then the scaffolds modified with or without glue were transplanted into rabbit's retina by 23 G pars plana vitrectomy. Intraocular pressure(IOP) and retina examination were assessed by ICare, fundus photograph and OCT. The adhesion effects of various concentration levels glue were analyzed by chi-square test. The cell adhesion rate of different scaffolds was analyzed by Mann-Whitney U test. One-Way ANOVA was used to compare the cell survival rate of different scaffolds. After transplantation, the IOP variance of rabbits was analyzed by repetitive measurement deviation analysis. Results Compared with the control groups, the maximum adhesion rate of the biological glue was 91.7% (χ2=8.79, P<0.05) at 30μl/cm2 concentration level. After 24h of cultivation, cell adhesion rate of glue-scaffold group (86.85%) was significantly higher than that of pure scaffold group (13.78%, U=0.01, P<0.05), while there was no significant difference between the cell survival rates of the two groups (F=7.235, P=0.11). There was no significant difference (F=79.16, P=0.07) between the IOP of viscosity modified group [(18.4+0.93) mmHg (1 mmHg=0.133 kPa)] and non- modified group [(17.1±0.04)mmHg]. The retina adhesion rate of viscosity modified scaffold was 80% at 7 days postoperatively, and the fundus examination showed no inflammatory response in retina and vitreous cavity. Conclusion This study showed that the biological glue has favorable viscosity modifying effect on tissue engineering neural retina scaffolds, which is beneficial for the biological material transplantation. (Chin J Ophthalmol, 2018, 54: 277-282) Key words: Retinal ganglion cells; Tissue engineering; Tissue scaffolds; Tissue adhesives; Adhesiveness