Preparation of N,O-carboxymethyl chitosan nanoparticles as an insulin carrier

Figures & data

Figure 1.  FTIR spectra of chitosan and NOCC.

Figure 2.  NMR spectrum of (A) chitosan, and (B) NOCC.

Table 1.  NOCC nanoparticles were obtained by inducing the gelation of different concentrations of NOCC with different concentrations of TPP, then samples were visually inspected and three different systems (•: clear solution, ▴: opalescent suspension, and ♦: aggregates) were identified.

TPP	NOCC
	1.0 mg/ml	2.0 mg/ml	3.0 mg/ml
0.1 mg/ml	•	•	•
0.5 mg/ml	•	•	•
1.0 mg/ml	♦	▴	♦

Figure 3.  TEM (the scale bar = 100 nm) of NOCC nanoparticles (A) NOCC-to-TPP weight ratio = 3, NOCC: 2 mg/ml; (B) NOCC-to-TPP weight ratio = 5, NOCC: 2 mg/ml; (C) NOCC-to-TPP weight ratio = 3, NOCC: 2 mg/ml, insulin: 0.5 mg/ml.

Figure 4.  Influence of NOCC-to-TPP weight ratio on insulin encapsulation efficiency for insulin-loaded NOCC nanoparticles (NOCC: 2 mg/ml and insulin: 1 mg/ml) (mean ± SD, n = 3).

Figure 5.  Effect of pH of solutions on the particle size (♦) and zeta potential (▴) of insulin-loaded NOCC nanoparticles (NOCC-to-TPP weight ratio = 3, NOCC: 2 mg/ml, insulin: 0.5 mg/ml).

Figure 6.  Influence of NOCC-to-TPP weight ratio on cumulative release of insulin from insulin-loaded NOCC nanoparticles (NOCC: 2 mg/ml and insulin: 0.5 mg/ml) in (A) pH = 2.5, and (B) pH = 7.4 of PBS (mean ± SD, n = 3).

Figure 7.  Influence of initial concentrations of insulin on cumulative release of insulin from insulin-loaded NOCC nanoparticles (NOCC-to-TPP weight ratio = 3, NOCC: 2 mg/ml) in pH = 7.4 of PBS (mean ± SD, n = 3).