The purpose of this investigation was to develop Pluronic F-127 coated N-trimethyl chitosan nanoparticles(F-S NPs)of insulin as the model drug and asses their penetration of the mucosal barriers. Single factor screening was used to optimize the formulations of nanoparticles and the nanoparticles were characterized. Their particle size, Zeta potential, encapsulation efficiencies and drug loading were assayed to be(240. 6±6. 51)nm, (10. 42±1. 60)mV, (43. 39±2. 83)% and(3. 39±0. 57)%, respectively. The impact of PF-127 on mucin binding in vitro and nanoparticles′s transport in freshly obtained mucus were also evaluated. The mucin affinity of F-S NPs was significantly reduced when compared to that of the N-trimethyl chitosan nanoparticles(S NPs), i. e. , 28% of the latter. And F-S NPs was found to have an improved mucosal penetrating capability. Mucus-secreting HT29-MTX-E12(E12)cell monolayer was selected to investigate their cellular uptake. F-S NPs exhibited higher penetration coefficient than both free insulin and S NPs in mucus-secreting epithelium cells, i. e. , 16-fold and 1. 4-fold, respectively. Data suggest that F-S NPs be potential carriers to cross mucosal barriers and enhance the cellular uptake of insulin.