Multifunctional polymeric micelles with folate-mediated cancer cell targeting and pH-triggered drug releasing properties for active intracellular drug delivery

Abstract

A new type of multifunctional polymeric micelle drug carrier for active intracellular drug delivery was prepared and characterized in this study. The micelle is a nano-supramolecular assembly with a spherical core-shell structure, and its surface and core were modified with piloting molecules for cancer cells and pH-sensitive drug binding linkers for controlled drug release, respectively. In order to prepare such micelles, self-assembling amphiphilic block copolymers, folate-poly(ethylene glycol)-poly(aspartate hydrazone adriamycin) [Fol-PEG-P(Asp-Hyd-ADR)], were specially designed and synthesized by installing a molecular promoter to enhance intracellular transport, folate (Fol), at the end of the shell-forming PEG chain and conjugating the anticancer drug, adriamycin (ADR), to the side chain of the core-forming PAsp segment through an acid-sensitive hydrazone bond. Because folate-binding proteins (FBP) are selectively overexpressed on the cancer cell membranes, the folate-bound micelles (FMA) can be guided to the cancer cells in the body, and after the micelles enter the cells, hydrazone bonds are cleaved by the intracellular acidic environment (pH 5-6) so that the drug release profile of the micelles is controlled pH-dependently. In this regard, FBP-binding selectivity of the prepared FMA was evaluated by surface plasmon resonance (SPR) measurements. The tetrazolium dye method (MTT assay) using human pharyngeal cancer cells (KB cell) revealed that FMA significantly improved cell growth inhibitory activity in spite of a short exposure time due to the selective and strong interaction between folate molecules and their receptors. Subsequent flow cytometric analysis showed that cellular uptake of FMA significantly increased. Consequently, these findings would provide one of the most effective approaches for cancer treatment using intracellular environment-targeting supramolecular drug carriers.

In vivo evaluation of riboflavin receptor targeted fluorescent USPIO in mice with prostate cancer xenografts

“…In this context, a rapid translocation of the vitamin-tagged cargo into cancer cells was observed via receptor-mediated endocytosis, e.g. for folic acid-and riboflavin (Rf)-tagged agents [6][7][8][9][10][11][12]. In this study, we focused on Rf, an essential vitamin that mediates various biochemical, physiological, and metabolic (e.g.…”

Combinatorial Polymeric Conjugated Micelles with Dual Cytotoxic and Antiangiogenic Effects for the Treatment of Ovarian Cancer

“…The reaction is performed in anhydrous DMSO (40 mL) under argon at 45 o C for 48 h. The resulting PEG-PBLA (3) is precipitated using diethyl ether and freeze dried from benzene. The next step in the synthesis is the preparation of PEG-p(Asp-Hyd) (PEG-HYD) (4) by aminolysis reaction 41,[52][53][54] . The reaction is carried out on PEG-PBLA (1.0 g, 0.05 mmol) by dissolving it in anhydrous N,N-dimethylformamide (DMF) (20 mL).…”

“…As seen in the drug release profile, the release of the drug from the polymer backbone is greater at pH 5.5 as compare to pH 7.4. This is expected as the hydrazone linker, LEV, is cleaved from the polymer backbone at acidic pH 42,[52][53][54]64 . The drugs release profile for the individual and mixed micelles did not reach 100% within 24 h, suggesting that some of the hydrazone bonds have not been cleaved during the experimental time frame.…”

“…Release of the conjugated drug(s) from the micelles over 24 h was performed under sink conditions at pH 7.4 (mimicking physiological pH), and pH 5.5 (mimicking acidic conditions associated with the endosomal/lysosomal pathway of cells) [52][53][54]64 . The release data for the PTX-M, RAP-M, and MIX-M along with their respective fitted curves is presented in (Fig.4).…”

A functional nanocarrier that copenetrates extracellular matrix and multiple layers of tumor cells for sequential and deep tumor autophagy inhibitor and chemotherapeutic delivery

“…The eGFP-LC3-expressing B16F10 cells (B16F10 eGFP-LC3 cells) were constructed by eGFP-LC3 plasmid transfection. 57 Briefly, cells were allowed to grow to 0.25-1 £ 10 6 per well (6-well) in 2 mL DMEM without antibiotics and were then transfected using Lipofectamine 2000 (Invitrogen, 11668027) according to the manufacturer's instructions. For each well, 14 mg pooled eGFP-LC3 plasmid was diluted in 700 mL OptiMEM (Gibco, 31985070).…”