ABSTRACT
Objective To prepare pH-responsive osmotic nanocarriers (pMPPs),observe their distribution in the genital tract mucosa in mice,and evaluate their radiosensitizing effects in tumor cells.Methods Amphiphilic polymers containing pH-sensitive hydrazone bonds were synthesized and pMPPs were prepared by ultrasonic emulsification.At the same time,the hydrophobic polymer polylactic acid-glycolic acid copolymer (PLGA) and the amphiphilic polymer PLGA-polyethylene glycol without hydrazine bond were selected,and the mucoadhesive nanoparticles(MPs) and mucus-penetrating particles (MPPs) were prepared in the same way.Fluorescence microscopy was used to observe the distribution of three kinds of nanocarriers labeled with fluorescent dye Cy5.5 in the genital tract mucosa.The toxicity of nanocarriers to human cervical cancer cell line HeLa was tested by thiazolyl blue assay.The amphiphilic polymer containing pH-sensitive hydrazone bond was combined with oil-soluble gold nanoparticles to form a multi-encapsulated nanocarrier,and its radiotherapy sensitization effect in HeLa cells was evaluated by thiazole blue assay.Results The pMPPs were successfully prepared with relatively uniform particle size and good dispersion.Fluorescence microscopy showed that pMPPs not only had good mucus permeability,but also could improve the endocytosis efficiency of the nanocarriers in reproductive tract mucosa.The results of thiazolyl blue test showed that when the concentration of the carrier reached to 0.80 mg/ml,the survival rate of HeLa cells in the pMPPs group was higher than 90％ which was higher than that in the MPs and the MPPs groups,indicating that pMPPs had good biosafety.The HeLa cell survival rate of the CMNa group (0.80 mg/ml) was higher than that of the multi-package nanocarrier group under different doses of X-ray irradiation (4 Gy:82.90％ vs.61.79％;8 Gy:64.75 ％ vs.42.36％).This result indicated that compared with the CMNa,a commonly used clinical radiotherapy sensitizer,the multi-encapsulated nanocarriers can more effectively enhance the sensitivity of tumor cells to radiation therapy,thereby improving the lethality of radiation therapy on tumor cells.Conclusion This study solved the conflict between mucus permeation and endocytosis design of nanocarriers in mucosal tissue application,and provided new insight for the treatment of mucosal tissue diseases.
ABSTRACT
BACKGROUND:To obtain more quantum dot (QD) barcodes,the overlay peaks of fluorescence occur,leading to difficulties in identifying QD barcodes.OBJECTIVE:To identify QD barcodes of two adjacent wave length using wavelet transform technique.METHODS:Through the microscopy,the spectrum of fluorescence induced by 375 nm light was captured by spectroscopy.The spectral signal was split into multi-scale components by wavelet transform.After transformed by spline function,every component constructed a new spectrum with peaks expanded by inverse wavelet transform.RESULTS AND CONCLUSION:Interpolation operation was performed on original data to control the data length to 2n.Following wavelet transform,peak location remained unchanged,so the eigenvalue of spectrum of coding fluorescence was extracted.The spectrum of fluorescence mixed with microspheres was split,and two QD barcodes were identified.The improved barcodes identification of adjacent spectrum increase color of QD barcodes,thereby enhancing code information volume.Results show that following spectrum was processed by wavelet transform,overlay peaks of fluorescence has be expanded,and enhanced the efficiency of recognition,which lays a foundation for detecting tumor markers.