Synthesis of novel polymeric nanoparticles (methoxy-polyethylene glycol-chitosan/hyaluronic acid) containing 7-ethyl-10-hydroxycamptothecin for colon cancer therapy: in vitro, ex vivo and in vivo investigation

Figures & data

Table 1. Individual variables in Box-Behnken design.

Independent variables (factors)	Levels
	Low	Medium	High
	−1	0	1	Units
X1: pH	3	4.5	6
X2: ratio of HA/mPEG-chitosan	1	10.5	20	% v/v
X3: concentration of Acid acetic	0.1	0.55	1	% w/v
Dependent variables (responses)		Unit		Goal
Y1: mean nanoparticles size (nm)		nm		Minimize
Y2: zeta potential (mV)		mV		Maximize
Y3: polydispersity Index		value		minimize
Y4: encapsulation efficiency (%)		%		Maximize

Figure 2. (A) Particle size and distribution and (B) SEM image of SN38-NPs.

Figure 3. DSC thermogram of (A) chitosan, (B) HA, (C) SN38 and (D) SN38-NPs.

Figure 4. FT-IR spectra of (A) HA, (B) SN38and (C) SN38-NPs.

Figure 5. (A) Cell viability of SN38-NPs and control on CCD-18co. (B) Cell viability studies of NPs, free SN38, SN38-NPs on Caco-2 cells. (C) C26 using resazurin assay (mean ± SD; n = 3, *p ≤ .05, **p ≤ .01 and *** p ≤ .001).

Figure 6. In vitro cellular uptake of free SN38, SN38-NPs and SN38- NPs without HA after 2 h and after 6 h (A) Caco-2 and (B) C26 (mean ± SD; n = 3). CLSM of Caco-2 cells (C) 2 h and (D) 6 h incubation with FDA loaded SN38-NPs with 20 x magnification level.

Figure 7. The release profile of SN38 from SN38-NPs and free SN38 from rat intestinal in medium (pH 7.4) as a function of time (mean ± SD; n = 3, **p ≤ .01).

Figure 8. In vivo anti-tumour efficacy of free SN38, NPs, SN38-NPs and normal saline into C26-tumour-bearing mice during the 30 days with respect to (A) tumour volume, (B) image of solid tumour and (C) body weight (mean ± SD; n = 5).