Polymer Science, Series A, 2017, Vol. 59, No. 3 SUPPORTING INFORMATION The Screening and Evaluating of Chitosan/β-cyclodextrin Nanoparticles for Effective Delivery Mitoxantrone Hydrochloride Yiwen Wang, Fei Qin, Mei Lu, Li Gao, and Xin Yao School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China e-mail: yaox@ucas.ac.cn (Xin Yao) Received August 8, 2016 Revised Manuscript Received December 31, 2016
Preparation and Characterization of CMβ-CD and GCS-CMβ-CD Polymers Preparation of CM m β-cd and GCS n -CM m β-cd Polymers. Briefly, 4.53 g chloroacetic acid was dissolved in 5 ml water, and then 8 ml NaOH solution with different concentration (3.75, 7.5, 10 M) was added with continuous stirring, β-cd (7.57 g) was then added to the solution. The mixture was stirred at 55 C for 12 h. During this process, another 2 ml different concentration of NaOH solution was added dropwise. After the reaction, the mixture was adjusted to ph 4.0 with HCl solution (1 : 1, v/v) and then extensively dialyzed against water (M w cutoff 1000). The final solution was precipitated with acetone, and the precipitate was dried under vacuum for 12 h at room temperature to obtain the final product, which with different number of carboxymethyl for each β-cd(cm m β-cd). GCS (10.6 mg) and three different CM m β-cds (24 mg) were separately dissolved in 10 ml water. 15 mg 1-(3-dimethylaminopropyl)-3- ethylcarbodiimide hydrochloride (EDC, Sigma) was added to CM m β-cd solutions as cross-linking agent with magnetic stirring at 300 rpm and stirred for 1 h at room temperature, then the prepared GCS solutions were added. The reaction mixture was continuously stirred for another 24 h, and then dialyzed by gradient against distilled water (M w cut-off 8000). The solution was freeze-dried to obtain cotton-like GCS n -CM m β-cd
powder with different amount of carboxymethyl and β-cd. Characterization of CM m β-cd and GCS n -CM m β-cd Polymers. The synthesized CM m β-cd was characterized by FTIR (VERTEX 70), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS, Autoflex III), and high-performance liquid chromatography (HPLC, Agilent 1100) with electrospray ionization mass spectrometry (ESI-MS, LCQDECA XP, Thermo Finnigan). Fig. S1. FTIR spectra of (1) β-cd, (2) CM 2-8 β-cd, (3) CM 0-5 β-cd, and (4) CM 3-7 β-cd.
The FTIR spectrum of CM m β-cd is shown in Fig. S1. The strong peak at 1704.3 cm -1 could be ascribed to the stretching vibration of carbonyl group [1, 2], which is not observed in β-cd. The existence of this characteristic peak indicates that the carboxymethylation of β-cd was successful. The components of CMβ-CD were measured by MALDI-TOF MS (Fig. S2). For an example of CMβ-CD, according to the mass-to-charge ratios (m/z), up to seven carboxymethyl groups could be added, generating β-cd-ch 2 COOH to β-cd-(ch 2 COOH) 7. HPLC/ESIMS was used to determine the relative CMβ-CD components contents (Fig. S3b, middle). There are six main peaks (Fig. S3a upper), and the relative contents of β-cd-(ch 2 COOH) 2 to β-cd-(ch 2 COOH) 7 were calculated from Fig. S3b (middle) as 3.00, 34.50, 32.75, 10.64, 9.90, and 6.10%, respectively. β-cd-(ch 2 COOH) 3 through β-cd-(ch 2 COOH) 7 are the main components, then taking about the content of carboxymethyl, this production is named CM 3-7 β-cd. Considering the content of every CMβ- CD component, the calculated average molar molecular weight (M w ) of CMβ-CD is 1328 g/mol. Except for one carboxymethyl group of CMβ- CD that reacted with the amino groups of GCS, the other carboxylic acid groups around the β-cd cavity are free [3, 4]. Similarly, for CMβ-CD a the relative contents of β-cd-(ch 2 COOH) 2 to β-cd-(ch 2 COOH) 8 were calculated as 11.72, 15.60, 16.42, 14.21, 11.72, 16.14, and 14.21% and
named CM 2-8 β-cd, the calculated average molar molecular weight (M w ) of CM 2-8 β-cd is 1426 g/mol; for CMβ-CD c the relative contents of β- CD to β-cd-(ch 2 COOH) 5 were calculated as 13.11, 16.81, 21.56, 18.86, 13.34, and 16.13% and named CM 0-5 β-cd, the calculated average molar molecular weight (M w ) of CMβ-CD C is 1277 g/mol. Fig. S2. MALDI-TOF MS spectra of (a) CM 2-8 β-cd, (b) CM 3-7 β-cd, and (c) CM 0-5 β-cd.
Fig. S3. (a) Total ion current chromatogram of seven CMβ-CD components. (b) The selected ion chromatograms of CMβ-CD components. CMβ-CD (upper): (1) β-cd-(ch 2 COOH) 2,m/z: 1249.5 1250.5; (2) β-cd-(ch 2 COOH) 3,m/z: 1307.5 1308.5; (3) β-cd- (CH 2 COOH) 4, m/z: 1365.5 1366.5; (4) β-cd-(ch 2 COOH) 5, m/z:
1423.5 1424.5; (5) β-cd-(ch 2 COOH) 6, m/z: 1481.5 1482.5; (6) β-cd- (CH 2 COOH) 7, m/z: 1539.5 1540.5; (7) β-cd-(ch 2 COOH) 8, m/z: 1597.5 1598.5; CMβ-CDV (middle): (1) β-cd-ch 2 COOH, m/z: 1191.5 1192.5; (2) β-cd-(ch 2 COOH) 2, m/z: 1249.5 1250.5; (3) β-cd- (CH 2 COOH) 3, m/z: 1307.5 1308.5; (4) β-cd-(ch 2 COOH) 4, m/z: 1365.5 1366.5; (5) β-cd-(ch 2 COOH) 5, m/z: 1423.5 1424.5; (6) β-cd- (CH 2 COOH) 6, m/z: 1481.5 1482.5; (7) β-cd-(ch 2 COOH) 7, m/z: 1539.5 1540.5; CMβ-CD (down): (1) β-cd, m/z: 1133.5 1134.5; (2) β- CD-CH 2 COOH, m/z: 1191.5 1192.5; (3) β-cd-(ch 2 COOH) 2, m/z: 1249.5 1250.5; (4) β-cd-(ch 2 COOH) 3, m/z: 1307.5 1308.5; (5) β-cd- (CH 2 COOH) 4, m/z: 1365.5 1366.5; (6) β-cd-(ch 2 COOH) 5, m/z: 1423.5 1424.5. The graft amount of CMβ-CD was determined by the concentrated sulfuric acid and phenol colorimetric method with UV-vis [5]. CMβ-CD can be dehydrated to its furfurol derivative after being treated with concentrated H 2 SO 4. The derivative can react with phenol, forming an orange acetal compound with maximum absorption at 489 nm. The GCS dehydrated derivative does not have an aldehyde group, so no orange compound can form after the addition of phenol. Therefore, the UV-vis method can not only recognize the existence of CMβ-CD but also determine the amount of CMβ-CD.
Here Q is used to express the degree of substitution as: Q C V M w m, where C is the concentration of CMβ-CD calculated from the calibration formula. V is the volume of the sample solution. M w is the molar average molecular weight of CMβ-CD. Table S1 also shows the degree of substitution of three GCS n -CM m β- CD. With the increasing amount of CMβ-CD, Q decreased from 510 to 282 μmol/g. Thus, it is easy to obtain high ratio of N GCS /N CMβ-CD polymer. Table S1. The synthesis conditions of GCS n -CM m β-cd and results polymer GCS 2.8 -CM 2-8 β-cd GCS 7.5 -CM 3-7 β-cd GCS 11.0 -CM 0-5 β-cd CMβ-CD, M w, g/mol CMβ-CDA 1426 CMβ-CDB 1328 CMβ-CDC 1277 GCS/CMβ-CD Q, μmol/g N GCS /N CMβ-CD 3 : 1 510 2.8 3 : 1 346 7.5 3 : 1 282 11.0 The Graft Amount of CMβ-CD. Through three different CMβ-CD used during synthesis, three polymers with different amounts of CMβ-CD were prepared. The products are called GCS n -CM m β-cd, with n
indicating how many GCS units have one CMβ-CD (N GCS /N CMβ-CD ). Curves 1, 2, and 3 and 4 in Fig. S4 are the UV spectrum of the three polymers and GCS at the same concentration. As noted above, there is obvious absorption of the three polymers, while there is no absorption for GCS because it had no aldehyde group, further proving that CMβ-CD was cross-linked onto the GCS backbone and that the GCS-CMβ-CD was successfully synthesized. Fig. S4. UV-vis spectra of (1) GCS 2.8 -CM 2-8 β-cd, (2) GCS 7.5 -CM 3-7 β- CD, and (3) GCS 11.0 -CM 0-5 β-cd; (4) GCS. The inset showed the UV-vis calibration curve of (1) CM 2-8 β-cd, (2) CM 3-7 β-cd, and (3) CM 0-5 β-cd.
The inset of Fig. S4 is the calibration curve of different CM m β-cd, and the calibration formula is CM 2-8 β-cd: A = 0.01704 + 7.84C CMβ-CD (mg/ml), CM 3-7 β-cd: A = 0.05947 + 7.9C CMβ-CD (mg/ml), CM 0-5 β-cd: A = 0.02611 + 7.37C CMβ-CD (mg/ml). The degree of substitution Q was obtained based on equation 1 and is show in Table S1. N GCS /N CMβ-CD can be calculated from the calibration formula. For the three polymers, they are 2.8, 7.5 and11.0. Overall, we obtained three different GCS n -CM m β- CDs: GCS 2.8 -CM 2-8 β-cd, GCS 7.5 -CM 3-7 β-cd, and GCS 11.0 -CM 0-5 β-cd. REFERENCES 1. M. Prabaharan and S. Gong, Carbohydr. Polym. 73(1), 117 (2008). 2. J. Ji, Sh. Hao, W. Liu, J. Zhang, D. Wu, and Y. Xu, Polym. Bull. 67(7), 1201 (2011). 3. J.-M. Yu, Y.-J. Li, L.-Y. Qiu, and Y. Jin, Eur. Polym. J. 44(3), 555 (2008). 4. H. Tan, Y. Xue, Q. Luan, and X. Yao, Anal. Methods 4(9), 2784 (2012). 5. M. DuBois, G. K. A. Gilles, J. K. Hamilton, and P. A. Rebers, Anal. Chem. 28, 350 (1956).