Technical Reference #1689

1689.

Degradable Poly(Beta-amino ester) Nanoparticles for Cancer Cytoplasmic Drug Delivery Youqing Shen; PhD; Huadong Tang; PhD;b Yihong Zhan; BS; Edward A. Van Kirk; MS; William J. Murdoch; PhD, Zhejiang University, Nanomedicine: Nanotechnology; Biology; and Medicine, 5(1689), (2009)
Link To Paper

Abstract:
Fast cytoplasmic drug delivery can overcome cancer cells' drug resistance and thus have an enhanced therapeutic efficacy. Such a drug delivery regime requires drug carriers capable of entering cancer cells localizing and rapidly releasing the drug into endosomes/lysosomes and subsequently disrupting their membranes to release the drug into the cytosol. We herein report a low-toxic and degradable poly(β-amino ester)-graft-polyethylene glycol (BAE-PEG) co-polymer forming pHresponsive nanoparticles capable of cytoplasmic drug delivery. BAE-PEG was synthesized by condensation polymerization of diacrylate and piperazine in the presence of a PEG-diacrylate macromonomer. BAE-PEG with 2% or 5% PEG side chains formed micelles (nanoparticles) with diameters of about 100 nm. The BAE-PEG nanoparticles were shown to rapidly enter cancer cells localize in their endosomes/lysosomes and subsequently disrupt them to release the drugs into the cytosol. Camptothecin loaded in the nanoparticles had a higher cytotoxicity to SKOV-3 ovarian cancer cells than free camptothecin.

Keywords:
Cytoplasmic drug delivery; pH-responsive nanoparticles; Graft polymers; Lysosomal escape

Materials & Methods:
SKOV-3 ovarian cancer cells were plated onto glassbottom Petri dishes (MatTek Ashland Massachusetts) at 80000 cells per plate in 2 mL of RPMI-1640 medium (Sigma) supplemented with 10% fetal bovine serum. The plates were incubated for 24 hours at 37°C in a humidified atmosphere of 95% air and 5% CO2. The original medium was then removed and replaced with 1 mL of fresh medium. The solution of the BAE-PEG05 nanoparticles loaded with DOX (6.2 wt%) prepared similarly as described above was added at a DOX concentration of 1.5 μg/mL. Images were taken using a Leica TCS SP2 microscope after culturing for 2.5 hours and 7.5 hours. LysoTracker (Molecular Probes Carlsbad California) was added to the wells at a concentration of 150 nM 1 hour before the pictures were taken. Cells were kept at 37°C in a humidified atmosphere of 95% air and 5% CO2 except when observed on the microscope. LysoTracker was observed using a 488-nm laser and the emission wavelength was read from 510 nm to 540 nm and expressed as green. Nanoparticles carrying DOX were observed using a 488-nm laser and the emission wavelength was read from 560 nm to 620 nm and expressed as red.

Microscopic Technique
Confocal Microscopy

Cell Type(s)
SKOV-3