A complex micellar system co-delivering curcumin with doxorubicin against cardiotoxicity and tumor growth

Figure 1. Preparation of CPMDC, the complex polymeric micelles dually loaded with DOX and CUR. Notes: (A) Scheme of two-step preparation by a thin-film hydration method. 1. Self-assembly of the micelles loading CUR on mPEG–PCL–BP. 2. The pH-induced co-encapsulation of DOX into micelles. (B) Molecular dynamics simulation of CPMDC formation. The copolymer is represented with gray solid surface, while CUR and DOX are shown in yellow or green stick rendering, respectively. Abbreviations: CPMDC, complex polymeric micelles co-encapsulating DOX and CUR; DOX, doxorubicin; CUR, curcumin; mPEG, monomethoxy poly(ethylene glycol); PCL, poly(ε-caprolactone); BP, N-t-butoxycarbonyl-phenylalanine.

Figure 2. Characterization of CPMDC obtained under the optimal formulation. Notes: (A) Particle size in 1% or 10% BSA at 37°C for 24 h (*p<0.05 and **p<0.01). (B) Zeta potential in 1% or 10% BSA at 37°C for 24 h (*p<0.05 and **p<0.01). (C) Cumulative release profile in PBS at 37°C for 72 h. (D) Effect of various formulations on in vitro viability of H9C2 cells. The cells were seeded into 96-well plates and treated as indicated, and the cell viability was detected by MTT assay after 24 h incubation. **p<0.01 compared with the NC group; ***p<0.01 compared with the DOX group. All data are expressed as mean±SD of triplicate determinations. Abbreviations: CPMDC, complex polymeric micelles co-encapsulating DOX and CUR; BSA, bovine serum albumin; PBS, phosphate-buffered solution; NC, normal control; DOX, doxorubicin; CUR, curcumin; BM, blank micelle.

Figure 3. Effect of various formulations on tumor growth in vivo. Notes: The C57BL/6 mice transplanted with B16 melanoma tumors were randomly divided into five groups (NC, DOX, CUR, cocktail and CPMDC) and subjected to treatment with various formulations under the same administration regime. In the end, the mice were sacrificed and the tumors were peeled off for further analysis. (A) The tumor image. (B) Tumor weight. *p<0.01 compared with NC group. (C) DOX content in tumor. **p<0.01 compared with DOX group. All data are expressed as mean±SD of nine replicates. Abbreviations: NC, normal control; DOX, doxorubicin; CUR, curcumin; CPMDC, complex polymeric micelles co-encapsulating DOX and CUR.

Figure 4. Cardiac toxic effect in rats singly i.p. administered with various formulations at equivalent dosages of 20 mg/kg DOX and 64 mg/kg CUR. Notes: At 48 h posttreatment, the rats were sacrificed and the heart tissue and plasma sample were harvested for further analysis. (A) BWC (column chart) and CWI (line chart). *p<0.01 compared with NC,a DOXb and cocktail.c (B) Representative fields of pathological change in rat left ventricles obtained by light microscope observation. The black arrows indicate the representative morphological changes: cell necrosis, superficial cytoplasm and nucleus and transverse structure loss (×400). (C) Levels of SOD, MDA and GSH-Px in the heart. **p<0.01 and *p<0.05 compared with the NCgroup, ***p<0.01 and ****p<0.05 compared with the DOX group, respectively. (D) Plasma levels of LDH, CK and cTnT. **p<0.01 and *p<0.05 compared with the NC group, ***p<0.01 and ****p<0.05 compared with the DOX group. All data are expressed as mean±SD of six replicates. Abbreviations: DOX, doxorubicin; CUR, curcumin; BWC, body weight change; CWI, cardiac weight change; NC, normal control; SOD, superoxide dismutase; MDA, malondialdehyde; GSH-Px, glutathione peroxidase; LDH,…

Figure 5. PK profiles in rats singly i.p. administered with various formulations at equivalent dosage of 20 mg/kg DOX and 64 mg/kg CUR. Notes: (A) The plasma concentration–time curve of DOX. (B) The plasma concentration–time curve of CUR. (C) DOXol content in rat heart harvest 48 h after administration. **p<0.01 compared with the DOX group. All data are expressed as mean±SD of six replicates. Abbreviations: PK, pharmacokinetic; DOX, doxorubicin; CUR, curcumin; CPMDC, complex polymeric micelles co-encapsulating DOX and CUR; DOXol, doxorubicinol.