Mechanical properties
Mechanical properties were determined for suits obtained by wet phase inversion using a PVP blowing agent and those obtained using nanofibers. The obtained results were compared with the properties measured for a suit with PLA without the use of a blowing agent (Table 4). Stress curves of scaffoldings obtained without blowing agent both from PLLA and from PCL were characteristic for durable, hard materials, with yield stress. [60]
A higher Young’s modulus was observed in scaffolds without porophores with PLLA (271.7 ± 17.1 MPa) than with PCL (48.2 ± 3.3 MPa) (Fig. 8). It was similar in the case of maximum stress where a higher value (9.46 ± 0.59 MPa) was obtained for PLLA than for PCL (5.68 ± 0.85 MPa). In contrast, scaffolds made of PCL (647.6 ± 91.6%) showed a higher maximum relative elongation than PLLA (77.2 ± 5.3%). All scaffolds tested exhibited excellent mechanical properties (E> 10 MPa), while scaffolds made of PLLA were more flexible than those made of PCL.[61] PLLA scaffolds with PVP (124.5 ± 20.8 MPa) and PCL scaffolds with PVP (8.7 ± 1.3 MPa) were smaller Young’s modulus.
All scaffolds obtained with the participation of nanofibers had a stress curve characteristic for elastic materials without a yield point.[60] In PLLA scaffolds obtained with the addition of non-woven fabric made of gelatin, Young’s modulus was 231.6 ± 70.4 MPa, the maximum stress was 7.31 ± 0.07 MPa, and the maximum strain was 6.1 ± 0.7%.
Table 4 Comparison of mechanical properties of selected suits that best meet the requirements for cartilage tissue regeneration.