3.3.4. In vivo degradation of the P4HB scaffold
The degradation of P4HB scaffold was determined by change in molecular weightover time (Figure 5A). The average Mw of the P4HB scaffold gradually decreased significantly over time, 279 ± 3 kDa (SD), 201 ± 5 kDa (SD) and 104 ± 7 kDa (SD) at 0-, 60- and 180- days post-implantation, respectively. The integrity and morphological changes of the implant was visualised by SEM (Figure 5B). The monofilament of P4HB scaffold with smooth surface pre-implantation kept its overall macroscopic integrity at both time-points. SEM images revealed the formation of fibre surface erosion over time. At 60 days, there were only superficial scratches on the fibres, which gradually progressed into surface fissuring over 180 days post-implantation.
Figure 5.