Supporting Information: Cupreous Complex-Loaded Chitosan Nanoparticles for Photothermal Therapy and Chemotherapy of Oral Epithelial Carcinoma Min Lin, Dandan Wang, Shuwei Liu, Tingting Huang, Bin Sun, Yan Cui, Daqi Zhang,,* Hongchen Sun,,* Hao Zhang,,* Hui Sun, and Bai Yang State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China, Department of Oral Pathology, School and Hospital of Stomatology, Jilin University, Changchun 130021, P. R. China, and Department of Thyroid Surgery, China-Japan Union Hospital, Jilin University, Changchun 130033, P. R. China. * Address correspondence to hao_zhang@jlu.edu.cn; hcsun@mail.jlu.edu.cn; daqizhang@yeah.net S-1
Figure S1. FTIR spectroscopy of sodium citrate, citric acid, CuCC NP, and chitosan. The characteristic peak of -COO - and -COOH is found at 1520 and 1720 cm -1, respectively. S-2
Calculation S1. Molar extinction coefficient (Q ext ) is an essential parameter to evaluate the capability of NPs for absorbing light. The Q ext of CuCC NP at 808 nm is calculated according to the following equation: A808ρV NPV0 N A Qext = Lm0 Where A 808 is the absorption intensity of CuCC NP at 808 nm; ρ is the mass density of CuCC NP and is measured as 3.97 g/cm 3 ; V NP is the average volume of one NP and can be determined from TEM observation; V 0 is the volume of NP solution; m 0 is the total mass of NP; N A and L represent the Avogadro s constant and the optical distance (1 cm), respectively. The calculated Q ext for CuCC NPs is 4.7 10 7 M -1 cm -1. As the molar absorption coefficient (ε) of cupreous complexes is determined as 40.6 M -1 cm -1, the extinction ability fully depends on the cupreous complex in the CuCC NP. 1 mole of CuCC NPs contains ~1.16 10 6 mole of cupreous complexes, taking up ~37 % of the fed CuCl 2. S-3
Figure S2. The photothermal conversion efficiency is measured under the laser power density of 3.5 W/cm 2. 2.0 ml solution of 8 mm cupreous complexes is added into 1 1 4 cm quartz pool with tinfoil capped to prevent the vaporization of water. The temperature is determined by an electric thermometer above the light path and recorded at the interval of 15 s. The solution is irradiated for 1440 s until the top temperature gets stable, and cooled to room temperature under ambient environment. (a) The real-time temperature. (b) Time constant for heat transfer from the system is determined to be τ s = 414.09 s by applying the linear time data from the cooling period (after 1440 s) versus negative natural logarithm of driving force temperature. S-4
Figure S3. TGA curves of chitosan and citric acid. S-5
Figure S4. (a) Photothermal performance of CuCC NPs by altering the concentrations. The power density is fixed at 3.5 W/cm 2. (b) Photothermal performance of CuCC NPs by altering laser power density. The concentration is fixed at 2.5 mg/ml. (c, d) The corresponding photothermal performance of cupreous complexes is also recorded with the same parameters. The carboxylate-to-cu(ii) ratio in the complexes is 6/1. The time interval is 15 s. The ambient temperature is 25 ºC. S-6
Figure S5. Photothermal performance of cupreous complexes versus carboxylate-to-cu(ii) molar feed ratio. The power density is fixed at 3.5 W/cm 2. And the concentration is 8 mm. S-7
Figure S6. (a, b) The colloidal stability of CuCC NPs under laser irradiation is tested with a 4 W/cm 2 808 nm laser. The NP solution is heated up and cooled down for 5 cycles. (a) Absorption spectra before and after 5 cycles are compared. (b) Real-time temperature is recorded by the time interval of 15 s. (c) The stability of CuCC NPs in ph 3.5 aqueous solution, saline, PBS, and cell culture without and with 10% serum is tested by incubating the NPs in solution for 3 days. The concentration of CuCC NPs is 2 mg/ml. S-8
Figure S7. The percentage of released cupreous complexes from CuCC NPs after 24 h under different ph. The concentration of CuCC NPs is 5 mg/ml. S-9
Figure S8. The cell viability as incubation of KB cells with cupreous complexes is compared. The concentration of cupreous complexes is 0, 9.25, 18.5, 37, 74, 111, 148 and 185 µg/ml, which is equal to the content of cupreous complexes in the CuCC NPs of 0, 25, 50, 100, 200, 300, 400, and 500 µg/ml, respectively. S-10
Figure S9. Bright field (a) and fluorescent (b-f) images of KB cells after incubating with different concentrations of cupreous complexes for 10 min and PI staining. The concentration of cupreous complexes is 0 (a, b), 5 (c), 10 (d), 25 (e), and 50 (f) µg/ml, respectively. The scale bar is 50 µm. S-11
Figure S10. The ratio of neutrophilegranulocyte (NE) and lymphocyte (LY) in the white blood cells. The mice treated by CuCC NPs show higher proportion of NE than the control group. S-12