In Vitro and In Vivo Degradation of Oxidized Acetyl- and Ethyl-Cellulose Sponges

Figures & data

Figure 1 Relative mass loss of sponges over time at pH 7.4 (in 0.1 M phosphate buffered saline) under infinite sink conditions at 37°C.

Figure 2 Relative mass loss of sponges over time at pH 6.0 (in 0.1 M acetate buffered saline) under infinite sink conditions at 37°C.

Figure 3 Relative mass loss of sponges over time at pH 5.0 (in 0.1 M acetate buffered saline) under infinite sink conditions at 37°C.

Table 1. Histomorphometric analysis on the in vivo degradation of AC and EC sponges^[1]

Sponge type	10 weeks (%)^[2]	30 weeks (%)^[2]	60 weeks (%)^[2]
Acetyl cellulose 2.5% (AC2.5)	3.7 ± 1.9 (*)	11.4 ± 3.7	41.1 ± 3.3 (*, |, #)
Acetyl cellulose 5.0% (AC5.0)	0.9 ± 0.3(**)	7.7 ± 2.1	25.2 ± 2.8 (**, |)
Ethyl cellulose 2.5% (EC2.5)	0.6 ± 0.2(***)	2.8 ± 0.7	11.6 ± 2.9 (***, #)
Ethyl cellulose 5.0% (EC5.0)	Not available	2.3 ± 1.5	8.8 ± 3.6

^[1]Performed on histology sections to determine the level of in vivo biodegradation of AC2.5, AC5.0, EC2.5 and EC5.0 sponges, at 10, 30, and 60 weeks post-implantation. Sixteen measurements from 8 different histology sections were performed for each experimental group.

^[2]Data were expressed as the mean ± SD. Statistical analysis was carried out using the unpaired Student's t test. A value of P < 0.05 was considered to be statistically significant [(*,*); (**,**); (***,***); (|, |); (#, #)].

Figure 4 Histological appearance of sponge implants retrieved: (A) after 10 weeks [AC5.0]; (B) after 10 weeks [AC2.5]; (C) after 30 weeks [AC2.5]; (D) higher magnification of C; (E) adjacent tissue at 60 weeks post-implantation [AC2.5]; (F) higher magnification of E; P: polymer, arrows: capillaries; FP: fat pad; H&E-stainings; scale bars = 100 µm.

Figure 5 SEM images of sponge implants: (A) new prepared [AC5.0]; (B) new prepared [AC2.5]; (C) 10 weeks post-implantation [AC2.5]; (D) 30 weeks post-implantation [AC2.5]; (E) 60 weeks post-implantation [AC2.5].