Biodegradability and biocompatibility study of poly(chitosan-g-lactic acid) scaffolds

Abstract

A biodegradable, biocompatible poly(chitosan-g-lactic acid) (PCLA) scaffold was prepared and evaluated in vitro and in vivo. The PCLA scaffold was obtained by grafting lactic acid (LA) onto the amino groups on chitosan (CS) without a catalyst. The PCLA scaffolds were characterized by Fourier Transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The biodegradabilty was determined by mass loss in vitro, and degradation in vivo as a function of feed ratio of LA/CS. Bone marrow mesenchymal stem cell (BMSC) culture experiments and histological examination were performed to evaluate the PCLA scaffolds' biocompatibility. The results indicated that PCLA was promising for tissue engineering application.

Figure 1

IR spectra of CS, PLA and PCLA-III (LA: CS = 4:1, w/w) copolymer.

Figure 2

SEM images of the outer surfaces of (A) CS; (B) PCLA-Ι (LA: CS = 2:1, w/w); (C) PCLA-Ⅱ (LA: CS = 3:1, w/w); (D) PCLA-Ⅲ (LA: CS = 4:1, w/w).

Figure 3

Degradation of PCLA materials by lysozyme (4 mg/mL) at pH = 7.4 and 37 °C (mean ± SD, n = 3).

Figure 4

The pH value in PBS by sodium azide (0.01 wt %) at 37 °C for up to 16 weeks(mean ± SD, n = 3).

Figure 5

In vivo biodegradation data for CS, PLA and PCLA scaffolds subcutaneously implanted into the backs of Kunming mice for up to 16 weeks (mean ± SD, n = 6).

Figure 6

The growth of BMSCs on materials for 1, 3, 5, 7, 10 days cultivation, viability was determined by the MTT assay and analysis by the one-way ANOVA (mean ± SD, n = 3; * p ≤ 0.05 compared with CS and ^# p ≤ 0.01 compared with CS).

Figure 7

Histological sections of CS, PCLA and PLA scaffolds after 1 week of implantation (A) CS; (B) PCLA-Ι; (C) PCLA-ΙΙ; (D) PCLA-ΙΙΙ; (E) PLA.M stand for materials and T stand for tissues (100×).

Figure 8

Histological sections of CS, PCLA and PLA scaffolds after 4 weeks of implantation (A) CS; (B) PCLA-Ι; (C) PCLA-ΙΙ; (D) PCLA-ΙΙΙ; (E) PLA.M stand for materials and T stand for tissues (100×).

Figure 9

Histological sections of CS, PCLA and PLA scaffolds after 8 weeks of implantation (A) CS; (B) PCLA-Ι; (C) PCLA-ΙΙ; (D) PCLA-ΙΙΙ; (E) PLA.M stand for materials and T stand for tissues (100×).