Supplementary Materials

Synthesis and Characterization of Thiolated

Carboxymethyl Chitosan-graft-CyclodextrinNanoparticles as a Drug Delivery Vehicle for Albendazole

Ghazaleh Alamdarnejad 1, Alireza Sharif 2,*, Shahrouz Taranejoo 3, Mohsen Janmaleki 3, Mohammad Reza Kalaee 4, Mohsen Dadgar 5 and Mazyar Khakpour 6

1 Young Researchers Club, South Tehran Branch, Islamic Azad University, Tehran, Iran

2 Department of Polymer Engineering, Faculty of Chemical Engineering, Tarbiat Modares University, P.O. Box: 14155/143, Tehran, Iran

3Medical Nanotechnology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran

4Department of Polymer Engineering, Islamic Azad University, South Tehran Branch, Tehran, Iran

5Faculty of Applied Chemistry, Islamic Azad University, South Tehran Branch, Tehran, Iran

6 Department of Polymer Engineering, Islamic Azad University, Kashan Branch, Kashan, Iran

*Corresponding author E-mail:

Tel/Fax: +982182884382

Experimental design.

In order to determine the optimum conditions for preparation of TGA-CMC-CD systems, containing the highest amount of immobilized thiol groups, a five-level two-factor central composite design (CCD), based on the Response Surface Methodology (RSM)[1], was utilized.Among the factors that can influence the amount of coupled thiol groups to CMC-CD polymer, weight ratio of TGA to CMC-CD polymer, x1, and EDC concentration, x2, were considered as the most important factors and their variations were studied in 5 levels (Table S1). Table S2 summarizes CCD design. The experiments were run in random order to give randomly distributed variables. At first a response surface model (y) of second order based on the CCD methodology was developed to consider the possible effect of interaction of the factors:

y = β0+ β1x1+ β2x2+ β12x1x2

where y, β0,β1, β2and β12 are the response value calculated by the model (coupled thiol groups amount), the offset term, the linear effect of factor x1, the linear effect of factor x2 andthe interaction effect of the factors, respectively.Data were analyzed and the coefficients were interpreted using the F-test and analysis of variance (ANOVA) was performed to establish the optimum conditions.

However, it was found by fitting the obtained experimental data (Table S2) to various models using the Design Expertsoftware (version8.0.6), that a linear modelcould describe the occurring of maximum thiol groups on the polymer more suitably.In other words, there was no significant interaction between the factors (x1 and x2) and henceβ12 was found to be zero. Also, β0,β1and β2coefficients of the linear model were calculated by the software as 140.71083, -11.20333and -0.78023, respectively. Therefore, model values of the amount of the coupled thiol groups are also included in Tabe S2.

The model predicted valuesare in good agreement with the experimental results. Based on the data of Table S2, choosing TGA to CMC-CD ratio as 0.75/1 and EDC concentration as 50 mM led to the TGA-CMC-CD polymer containing 115.65 (μmol/g polymer) of thiol groups.

In order to gain insight into the relationship between the factorsand the amount of immobilized thiol groups on the polymer, three dimensional and contour plots were investigated as shown in Fig. S1 and Fig. S2, respectively.The 3D as well as2D plots showed a linear relation between the two factors and the response, emphasizing again the suitability of choosing the linear model for analyzing the obtained experimental data.

Table S1
Variables used in the experimental design.
Factor / Levels
TGA/CMC-CD / 0.5 - 0.75 - 1 - 1.25 - 1.5
EDAC concentration (mM) / 25 - 50 - 75 - 100 – 125

Table S2

Experimental and model values for the amount of grafted thiol groups on TGA-CMC-CD polymers.

Factors / Amount of free thiol groups immobilized on polymer (μmol/g polymer)
Run order / TGA/CMC-CD (x1) / EDC (x2) (mM) / Experimental values / model values
1 / 0.5:1 / 75 / 89.46 / 85.83
2 / 0.75:1 / 50 / 115.65 / 101.25
3 / 0.75:1 / 100 / 32.92 / 37.75
4 / 1:1 / 25 / 88.21 / 93.61
5 / 1:1 / 75 / 65.07 / 62.48
6 / 1:1 / 75 / 74.87 / 70.09
7 / 1:1 / 75 / 87.76 / 83.66
8 / 1:1 / 125 / 33.42 / 38.02
9 / 1.25:1 / 50 / 91.56 / 93.29
10 / 1.25:1 / 100 / 49.8 / 48.68
11 / 1.5:1 / 75 / 52.17 / 51.22

Fig. S1. Three dimensional (3D) plot for the amount of grafted thiol groups on TGA-CMC-CD polymers as a function of TGA to CMC-CD ratio and EDC concentration.

Fig. S2. Contour plot of the combined effects of of TGA to CMC-CD ratio and EDC concentrationon the amount of grafted thiol groups on TGA-CMC-CD polymers

Reference

[1] G.E.P. Box, K.B. Wilson, On the Experimental Attainment of Optimum Conditions, J. Roy. Statist. Soc. Ser. B. 13 (1951) 1-45.

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