SN-38-loaded Electrospun Composite Nanofiber Scaffolds For Treatment Of Human Glioblastoma Cells In Vitro

ObjectiveTo built an effective controlled release system which was based on 7-ethyl-10-hydroxyl camptothecin (SN-38)-loaded electrospun composite nanofiber with poly (s-caprolactone) (PCL)/poly (D,L-lactide) (PDLLA),release drug slowly and steadily with low nerve stimulation, and evaluate its cytotoxicity antitumor activity against U-251 glioma cell in vitro.Method(1)SN-38 loaded PCL/PDLLA fibers were manufactured by electrospinning. The fiber morphology of the electrospun mesh was examined by scanning electron microscopy (SEM). The physical state of SN-38 within the polymeric fibers was investigated by different scanning calorimetry(DSC) and fourier transform infrared (FT-IR). The static wettability of the membrane was measured by contact angle analyzer.(2) Phosphate-buffered saline (PBS) was used to assess the release kinetics of SN-38 in a water bath shaker at 37℃ and 60 rpm/min. Circular pieces of SN-38-loaded fibrous mesh were placed in 10 mL of PBS. The concentration of SN-38 was measured by high-performance liquid chromatography (HPLC). The release speeds of two samples were measured, and calibration curves were constructed for SN-38. (3) After sterilization, the mesh samples were placed in permeable transwells and transferred to a 96-well plate containing tumor cells (already adherent for 5 hours) in 100μL of fresh DMEM supplemented with 10% fetal calf serum and 1% penicillin-streptomycin. The plates were incubated for 48 h at 37℃ in a 5% CO2 atmosphere. The medium and fiber sheets were removed and replaced with 100μL of medium at the indicated time points. Tumor cell viability was tested using the Cell Counting Kit-8 (cck-8). Cell viability was determined by measuring the ratio of the absorbance of the test cells to the absorbance of the control cells at a wavelength of 470 nm. Between the measurements, the membranes were placed in 24-well plates containing PBS at 37℃ in a 5% CO2 atmosphere, and the PBS was replaced every day.ResultsUniform SN-38 loaded PCL/ PDLLA fibers were obtained. The SEM images revealed that the electrospun fibers were smooth and did not contain crystals of SN-38 in their structure surface. The FT-IR peak which was observed for drug powder was not observed in the spectra of the SN-38-loaded nanofiber mats, indicating that the drug chemical functional groups were not damaged. Analysis of melting points of the drug-loaded mats by DSC indicating that the amount of drug in the fiber mats affected their thermal behavior. Cell toxicity test results showed that the SN-38 loaded PCL/ PDLLA fibers can continuously inhibit the U-251 glioma cell. Due to different materials and content of drug, different membranes showed different release time. The antitumor activity of the 2 wt.% SN-38 loaded PCL/PDLLA nanofiber meshes was controlled and sustained.ConclusionSN-38-loaded composite nanofiber of PCL/ PDLLA as a sustained delivery system is feasible. While the drug concentration is added, the release time of drug within the fibers will be increased accordingly. The 2 wt.% SN-38 loaded PCL/PDLLA nanofiber merit further evaluation as a method can to potentially prevent locoregional recurrence following surgical tumor resection.