In vitro biological compatibility of co-electrospun poly (lactide-co-glycolide)/polyethylene glycolnanofibrous membrane in tissue engineering scaffolds for spinal cord injury

Abstract

Objective To study the feasibility of a new type of tissue engineering scaffolds for spinal cord injury made of electrospun poly (lactide-co-glycolide) -polyethylene glycol (PLGA-PEG) nanofiber membrane and its biocompatibility with bone marrow stem cells (BMSCs). Methods Electrostatic spinning was used to prepare porous nanofiber scaffolds of PLGA-PEG and porous nanofiber scaffolds of polylactic glycolic acid (PLGA).The scaffolds were observed by scanning electron microscopy (SEM).BMSCs were separated from male SD rats and cultured.BMSCs of the third passage were seeded and cultured onto the scaffolds made of electrospun PLGA-PEG nanofiber membrane (the experimental group) and the scaffolds made of the electrospun PLGA nanofiber membrane (the control group),respectively.MTT (methyl thiazolyl tetrazolium) method was used to determine the toxicity and proliferation of the cells.The blood corpuscle counting plate was used to measure the adhesion rate 2,4 and 6 hours postinoeulation. DAPI (4'6-diamidino-2-phenylidole) dyeing was used to observe the nucleal morphology.The morphology,adhesion and growth of the cells after co-culture were observed by SEM. Results The scaffolds in the 2 groups had an interconnected porous network structure,with a fiber diameter of 655 ± 57 nm in the experimental group and of 539 ±48 nm in the control group respectively.The pores in the scaffolds were interconnected,with a porosity of 86.8％ ± 1.5％ and of 84.7％ ± 1.2％ respectively.MTT detection showed BMSCs grew well in bothgroups and the absorbance (OD) value increased over time with significant between-group differences at differenttime points (P ＜ 0.05).At each time point,the cell adhesion rate was significantly higher in the experimentalgroup than in the control group ( P ＜ 0.05).DAPI fluorescence staining showed normal morphology andquality of the nuclei,no obvious cellular apoptosis or necrosis in both groups,and significantly more cells inthe experimental group.SEM observed that BMSCs grew much better on the scaffolds in the experimentalgroup,proliferating massively and secreting matrix,than those in the control group. ConclusionThe porous nanofiber scaffolds of PLGA / PEG prepared by electrostatic spinning can be a new type of tissueengineering carrier for spinal cord injury research because they are safe,free of toxicity,and suitable forBMSCs growth with fine cyto-compatibility and a proper aperture and porosity. Key words: Spinal cord injuries; Tissue scaffolds; Bone marrow cells; Tissue engineering