Controlled release of pentoxifylline from porous chitosan-pectin scaffolds

Figures & data

Table 1.  Concentrations of chitosan and pectin in the solutions used to make films and scaffolds.

Chitosan (w/v%)	Pectin (w/v%)	Mix ratio (v/v)	Final concentration (w%)		Notations
			Chitosan	Pectin
1	—	—	1	—	C1
2	1	1:1	1	0.5	C1P0.5
2	2	1:1	1	1	C1P1
2	4	1:1	1	2	C1P2
4	2	1:1	2	1	C2P1

Table 2.  Conditions used in tests of anti-inflammatory effects of PTX release on macrophage cells in vitro.

	LPS^§	Blank scaffold	PTX^†	Scaffold loaded with 100 μg PTX
DMEM^*	−	+	−	−
DMEM+LPS	+	+	−	−
DMEM+LPS+PTX (in media)	+	+	+	−
DMEM+LPS+PTX (scaffold release)	+	−	−	+

^* DMEM: Dulbecco’s Modified Eagle’s Medium (1 mL/well).

^§ LPS: lipopolysaccharide. [LPS]= 1 μg/mL.

^† PTX: pentoxifylline. [PTX] = 100 μg/mL.

Table 3.  The decomposition temperatures, contact angles, swelling ratios, initial cell attachments (1.5 h after cell seeding), and compressional Young’s moduli of chitosan and pectin cross-linked chitosan films/scaffolds.

	Decomposition temperature (°C)	Contact angle (°)	Swelling ratio at 60 min (%)	Cell attachment at 1.5 h (%)*	Young’s modulus (kPa)
C1	306.4 ± 0.4^a	81.0 ± 2.6^a	35.0 ± 0.1^a	55.6 ± 4.2^a	2.4 ± 0.0^a
C1P0.5	252.8 ± 0.5^b	78.0 ± 1.6^a	34.3 ± 0.1^b	59.0 ± 1.0^a	2.6 ± 0.1^b
C1P1	248.5 ± 0.6^c	72.0 ± 1.6^b	32.6 ± 0.2^c	63.1 ± 1.0^b	2.9 ± 0.1^c
C1P2	245.1 ± 0.8^d	69.0 ± 1.2^b	30.5 ± 0.1^d	67.7 ± 0.8^b	3.7 ± 0.2^d
C2P1	254.3 ± 0.3^e	76.5 ± 1.7^a	27.1 ± 0.1^e	58.6 ± 2.2^a	5.8 ± 0.1^e

Results are expressed as mean ± standard deviation (two-way ANOVA).

Within the same column, numbers followed by different letters (a,b,c,d,e) are statistically different (p < 0.05).

* Cell attachment at 1.5 h on tissue culture polystyrene was (78.3 ± 1.4)%. It was higher than those of the five polymers tested (p < 0.05).

Figure 1.  FTIR spectra of polymers made of 1% chitosan (C1), 1% chitosan and 0.5% pectin (C1P0.5), 1% chitosan and 1% pectin (C1P1), 1% chitosan and 2% pectin (C1P2), and 2% chitosan and 1% pectin (C2P1).

Figure 2.  Representative SEM micrographs of (a) C1 (1% chitosan), (b) C1P0.5 (1% chitosan and 0.5% pectin), (c) C1P1 (1% chitosan and 1% pectin), (d) C1P2 (1% chitosan and 2% pectin), (e) C2P1 (2% chitosan and 1% pectin) scaffolds. Scale bar = 500 μm.

Figure 3.  The pentoxifylline release efficacies of 1% chitosan (C1), 1% chitosan and 0.5% pectin (C1P0.5), 1% chitosan and 1% pectin (C1P1), 1% chitosan and 2% pectin (C1P2), and 2% chitosan and 1% pectin (C2P1) scaffolds.

Figure 4.  TNF-α (a) and IL-6 (b) release from macrophage cells cultured in the four conditions listed in Table 2. * p < 0.05.

Figure 5.  The swelling ratios of 1% chitosan (C1), 1% chitosan and 0.5% pectin (C1P0.5), 1% chitosan and 1% pectin (C1P1), 1% chitosan and 2% pectin(C1P2), and 2% chitosan and 1% pectin (C2P1) scaffolds.