Figure 1.
Schematic representation for the synthesis of Poly(δ-valerolactone)/Poly(ethylene glycol)/Poly(δ-valerolactone)-Folate (VEV-FOL) by folic acid activation followed by esterification.
Figure 2.
Characterization of Poly(δ-valerolactone)/Poly(ethylene glycol)/Poly(δ-valerolactone)-Folate (VEV-FOL) by (a) Fourier Transform Infra Red spectra (FT-IR) recorded using potassium bromide pellets and (b) 1H Nuclear Magnetic Resonance spectra (1HNMR) recorded in CDCl3 as solvent.
Figure 3.
Transmission Electron Microscope (TEM) image of doxorubicin loaded Folate conjugated VEV micelles (FVEVDMs).
Table 1.
Characterization of doxorubicin entrapped Poly(δ-valerolactone)/Poly(ethylene glycol)/Poly(δ-valerolactone)-Folate micelles (FVEVDMs).
Figure 4.
In vitro release of doxorubicin from FVEVDMs and VEVDMs: Release pattern of DOX from micelles with and without folate in phosphate buffer at pH 7.4 and 37°C.
Figure 5.
Cellular uptake showing comparison of intracellular fluorescence of doxorubicin: Incubation of MDAMB231 cells with different doxorubicin formulations (1 µM) for 2 h is shown by (a) Confocal microscopy images showing intracellular fluorescence of doxorubicin (b) Flow cytometry histograms showing intensity of uptake (c) Comparison of uptake efficiency by intensity of doxorubicin fluorescence.
Bars marked with *p<0.05,***p<0.001 shows the level of significance of difference at the same concentration (n = 3).
Figure 6.
Cytotoxicity to MDAMB231 cells induced by (a) Blank micelles (100 µM) on incubation for 72 h (b) Different DOX formulations at different concentrations and time durations, as indicated. All the measurements were done in six replicates and the results are expressed as arithmetic mean ± standard error on the mean (S.E.M). Bars marked with *p<0.05,**p<0.01,***p<0.001 shows the level of significance of difference from free drug at the same concentration.
Figure 7.
(A) Apoptosis determined by flow cytometry in MDAMB231 cells treated with different DOX fomulations (0.01 µM) for 24 h after staining with Annexin V-FITC. Cells showing higher fluorescence (shift towards right) represent apoptosis (B) FACS analysis of Annexin V and PI in MDAMB231 cells treated with different DOX formulations (0.01 µM) for 24 h where Annexin V+ PI+; Annexin V+ PI−; Annexin V− PI+ and Annexin V− PI− indicate late apoptotic; early apoptotic; necrotic and live cells where a–e represent treatments as a:Control; b:Blank copolymer; c:Free DOX; d:VEVDMs; e:FVEVDMs.
Figure 8.
Comparison of PARP cleavage induced in MDAMB231 cells treated with different DOX formulations (2 µM) for 24 h where a–e represent a: Control; b: Blank copolymer; c: Free DOX; d: VEVDMs; e: FVEVDMs. Immunoblotting was carried out using antibodies specific for PARP and detected using enhanced chemiluminescence method.
Figure 9.
Variation in cell cycle of MDAMB231 cells on treatment with different DOX formulations (0.01 µM) for 24 h analyzed using FACS.
Figure 10.
Schematic representation of the structure of FVEVDMs and their targeting ability.
(a) Diagram showing the structure of DOX entrapped VEV-FOL copolymeric micelles having hydrophobic PVL core containing drug surrounded by PEG and folic acid as targeting molecules on the surface (b) Active cellular targeting ability of VEV-FOL micelles by specific binding to target cells and drug release on cellular internalization or in their close proximity.