The safety and slow-release effect of chitosan-nanoparticle on the transforming growth factor-β receptor Ⅱ aptamer / 中华实验眼科杂志

ABSTRACT

Background Our previous study demonstrated that the aptamer S58 specifically targeted transforming growth factor-β receptor Ⅱ (TβRⅡ) and inhibited the transdifferentiation of human Tenon capsule fibroblasts (HTFs) mediated by transforming growth factor-β (TGF-β).Chitosan-nanoparticles (CS-NP) are good drug carriers,but the efficacy and safety of CS-NP/aptamer complexes deserve attention.Objective The aim of this study was to synthesize a novel CS-NP/aptamer complex called CS (S58)-NP and investigate its properties and applicability.Methods Human Tenon capsule tissue was obtained from patients during strabismus surgery,and HTFs were cultured and passaged using the explant culture method.The fourth to tenth generations of cells were used in the experiment.Different concentrations of CS-NP were used to prepare the CS(S58)-NP by the ionic cross-linking method with a surface charge rate (N/P) for S58 of 10,20,30 or 40.The particle size and Zeta potential were measured by the Zeta analyzer.The shape and distribution of CS (S58)-NP particles were examined under the scanning electron microscope.The binding of CS-NP with S58 and resistance of CS (S58)-NP to DNase Ⅰ were examined by agarose gel eletrophoresis.The release rate of S58 from CS (S58)-NP in PBS was quantitatively analyzed by a ultraviolet spectrophotometer.The cytotoxicity of CS(S58)-NP to HTFs was evaluated by detecting the production of lactate dehydrogenase (LDH).Results The Zeta analyzer showed that the particle size of CS (S58)-NP was 130-270 nm and its electric potential ranged from + 16 to +28 mV.The CS (S58)-NP particles appeared spherical with an even distribution under the scanning electron microscope.The mean encapsulation efficiency of CS(S58)-NP was 88.9％,89.3％,91.7％ or 90.5％,respectively,when the N/P was 10,20,30 or 40.After being encapsuled by CS-NP,S58 could resist the degradation from DNase I.Its total releasing level in PBS increased with the lapse of time,with a maximum releasing speed at 24 to 36 hours.The total releasing level reached 100％ at 96 hours.With increaseing concentrations of CS(S58)-NP,the relative releasing level of LDH in HTFs suspension gradually elevated with a significant difference among the groups (F =588.018,P =0.000),with the highest released LDH level at 50 nmol/L of CS(S58)-NP (12.853％ ±0.375％).Conclusions CS-NP provides a protective and slow-releasing effect on the S58 aptamer.CS (S58)-NP shows a good biocompatibility with HTFs with a low cytotoxicity at a concentration of ＜50 nmol/L.CS(S58)-NP could be used to inhibit TGF-β induced transdifferentiation of HTFs in the future.