Polymer Nanocomposites Based Thermo-Sensitive Gel for Paclitaxel and Temozolomide Co-Delivery to Glioblastoma Cells.

Abstract

In this work, we have reported the preparation and optimization of paclitaxel (PTX) and temozolomide (TMZ) loaded monomethoxy (polyethylene glycol)-poly(D, L-lactide-co-glycolide) (mPEG-PLGA) nanocomposite which is a thermo-sensitive gel delivery system to glioblastoma. We utilized the orthogonal design and homogeneous design for the optimal drug-loaded nanoparticles (NPs) and composite gel prescription, respectively. The physicochemical characteristics of NPs and rheological properties of the gel were analyzed. Then the in vitro release of the gel was determined with a membrane-less diffusion system. Finally, the cytotoxic and apoptosis-inducing effects of the gel on the human malignant glioblastoma cell line U87 and C6 rat glioblastoma cell line were evaluated by MTT and flow cytometry apoptosis assay, respectively. The transmission electron microscopy (TEM) analysis revealed the optimized NPs with a relatively uniform diameter and distribution. The homogeneous design and rheological determination showed that the optimized gel prescription was 250 mg/mL Pluronic F127 (F127), 0.5% hydroxy propyl methylcellulose (HPMC-100M), 0.5% Pluronic F68 (F68), 0.5% sodium alginate (SA) and suitable NPs, which possessed the appropriate gelation behaviors: gelation temperature 28.01 degrees C, gelation time 127.1 s and corrosion speed 0.1892 g/cm2 x hr; and rheological properties: suitable elasticity modulus, viscosity modulus and low phase angle. The in vitro results suggested that the PTX and TMZ were sustainedly released from nanoparticles or the composite gel, and the release and elimination time greatly prolonged; and the composite gel possessed much higher growth-inhibiting effect and apoptosis-inducing rate in U87 and C6 cells than other formulations. These findings demonstrated that the optimal gel was a promising delivery system for the interstitial chemotherapy to glioblastoma.