In this study, we investigated in vivo
radiosensitizing effects of a gel-based dual drug delivery system (DDS) (PECE/DDP + mPEG-PCL/PTX, or
PDMP) in a
cervical cancer model, and determined its possible mechanisms of action. A xenograft
cervical cancer model was used to investigate the radio sensitization effect of
PDMP. Mice underwent
paclitaxel (PTX) + cisplatin (DDP), PECE, or
PDMP treatment followed by single radiation doses ranging from 0 Gy to 20 Gy. Radio sensitization was analyzed by
tumor regrowth delay (TGD). The sensitization enhancement ratio (SER) was calculated by the doses needed to yield TGD when using
radiation treatment alone and when using radiation plus drug treatment. The impact of irradiation and drugs on TGD was determined, and an optimum radiation dose was chosen for further evaluation of radio sensitizing effects. The data showed that
PDMP yielded the highest radio sensitization (SER was 1.3) and a radiation dose of 12 Gy was chosen for further investigation. PDMP + radiotherapy treatment was most effective in inhibiting
tumor growth, prolonging survival time, decreasing expression of CD31, CD133, and
aldehyde dehydrogenase 1 (ALDH1), inducing G2/M phase arrest, apoptosis, and expression of
Ataxia telangiectasia mutated (ATM) and
histone H2AX phosphorylation (γ-H2AX). Thus, our data indicated that
PDMP is a promising anti-
tumor and radio sensitization
reagent for the treatment of cervical
carcinoma.