Polyurethane-based three-dimensional printing for biological mesh carriers

Abstract

Repair and reconstruction of the myopectineal orifice area using meshes is the mainstay of surgical treatment of inguinal hernias. However, the limitations of existing meshes are becoming increasingly evident in clinical applications; thus, the idea of using three-dimensionally (3D)-printed biological meshes was put forward. According to the current level of the 3D printing technology and the inherent characteristics of biological materials, the direct use of the 3D printing technology for making biological materials into finished products suitable for clinical applications is not yet supported, but synthetic materials can be first printed into 3D form carriers, compounded with biological materials, and finally made into finished products. The purpose of this study was to develop a technical protocol for making 3D-printed biomesh carriers using polyurethane as a raw material. In our study: raw material, polyurethane; weight, 20-30 g/m²; weaving method, hexagonal mesh; elastic tension aspect ratio, 2:1; diameters of pores, 0.1-1 mm; surface area, 8 × 12 cm²; the optimal printing layer height, temperature and velocity were 0.1 mm, 210-220 °C and 60 mm/s. Its clinical significance lies in: (1) applied to preoperative planning and design a detailed surgical plan; (2) applied to special types of surgery including patients in puberty, recurrent and compound inguinal hernias; (3) significantly improve the efficiency of doctor-patient communication; (4) it can shorten the operation and recovery period by about 1/3 and can save about 1/4 of the cost for patients; (5) the learning curve is significantly shortened, which is conducive to the cultivation of reserve talents.

Figure 1

Effect illustration of a 3D-printed biomesh.

Figure 2

Data processing. (a) The overall structure of the curved surface is drawn. (b) The thickness is increased. (c) The hole-like hollow structure is designed. (d) Boolean operations on sets are used for processing the hole-like hollow structure. (e) A uniformly thin boundary is added. (f) An open-flow body is converted to a non-flow body.

Figure 3

Experimental layout.

Figure 4

Print carriers.

Figure 5

Structure of printed carrier under SEM.

Figure 6

Accuracy comparison tests. Note the red and blue parts of the scale area represent the range of the upper and lower deviation areas, respectively: the darker the red, the greater the upper deviation; the darker the blue, the greater the lower deviation; the smaller the deviation in the middle part, the lighter the corresponding colour.

Figure 7

Effect of polyurethane materials on cell viability.

Figure 8

Sample size calculation.