Assessment of the microstructure and mechanical properties of porous gelatin scaffolds

Gelatin scaffolds are in the interest of tissue engineering and drug release. The scaffold porosity and microarchitecture are of great importance in proper tissue regeneration. In this work, the freeze-drying method was used to produce the scaffolds. The effect of concentration of the initial gelatin solution and pre- -freezing temperature on the scaffold’s microstructure and microarchitecture (porosity, pores size, shape, and distribution) was evaluated. The mechanical tests of samples were performed. Moreover, the influence of the gentamicin sulphate addition on the gelatin scaffolds microstructure and mechanical properties was also studied. The linear relationship of porosity to the concentration of the initial solution was observed. Therefore, it is possible to obtain a scaffold with a planned porosity. Pores were interconnected with an aspect ratio between 1.5-1.8. For porosity 74 ± 9% the average pore size was 0.7 ± 0.6 mm, with most pores in the range 0.2-0.4 mm. For the samples with porosity 57 ± 14%, the average pore size was 0.2 ± 0.2 mm, with most pores in the range 0.05-0.2 mm. The process of pre-freezing the solution in liquid nitrogen caused the highest porosity of the sample, the smaller pores size and the lower pores size distribution in comparison to the sample pre-frozen in -20°C. The mechanical parameters for all the samples are sufficient for filling bone defects. The addition of a drug to gelatin caused only slight changes in the pore architecture. This material could be applied as a scaffold in the bone loss correlated to bacterial infection.