Polystyrene nanoplastics induce haematotoxicity with cell oxeiptosis and senescence involved in C57BL/6J mice.

Nanoplastics (NPs) has become a worrying serious environmental problem. However, the toxicological effects and mechanisms of NPs on hematopoiesis are still unknown. To this end, male C57BL/6J mice were directly exposed to the serial concentration gradient of polystyrene NPs (PSNPs, 0, 30, 60, and 120 µg d), respectively, for 42 days by intragastric administration. Results show that PSNPs were clearly visible in bone tissues, meanwhile, induced the count of major blood indicators (WBC, RBC, and LYM) decreased. H&E staining displayed that exposed to PSNPs can cause hematopoietic damage of BM and extramedullary hematopoiesis in spleen. Flow cytometry result show that the proportion of LSK represented a dose-dependent significantly decreased after PSNPs exposure. Further research found that PSNPs can cause the systemic oxidative stress occurs manifested as MDA accumulated. In addition, as the dose of PSNPs increased, the fluorescence intensity of Keap1 and p53 in femur sections gradually increased, meanwhile, the expression of cell oxeiptosis signal pathway Keap1/PGAM5/AIFM1 and the cell senescence signal pathway p53/p21 was all increased, markedly. Overall, our study demonstrated that PSNPs exposure caused oxidative stress, potentially resulting in cell oxeiptosis and senescence to develop haematotoxicity in C57BL/6J mice.

MPEG-CS/Bmi-1RNAi Nanoparticles Synthesis and Its Targeted Inhibition Effect on CD133+ Laryngeal Stem Cells.

Previous studies have confirmed that CD133+ cells in laryngeal tumor tissue have the characteristics of cancer stem cells. Bmi-1 gene expression is central to the tumorigenicity of CD133+ cells. In this study, we tried to develop a new siRNA carrier system using chitosan-methoxypolyethylene nanoparticles (CS-mPEG-NPs) that exhibit higher tumor-targeting ability and enhanced gene silencing efficacy in CD133+ tumor stem cells. It is hoped to block the self-renewal and kill the stem cells of laryngeal carcinoma. The mPEG-CS-Bmi-1RNAi-NPs were synthesized and their characters were checked. The changes in invasion ability and sensitivity to radiotherapy and chemotherapy of CD133+Hep-2 tumor cells were observed after Bmi-1 gene silencing. The mPEG-CS-Bmi-1RNAi-NPs synthesized in this experiment have a regular spherical form, a mean size of 139.70 ±6.40 nm, an encapsulation efficiency of 85.21 ± 1.94%, with drug loading capacity of 18.47 ± 1.83%, as well as low cytotoxicity, providing good protection to the loaded gene, strong resistance to nuclease degradation and high gene transfection efficiency. After Bmi-1 gene silencing, the invasion ability of CD133+ cells was weakened. Co-cultured with paclitaxel, the survival rates of CD133+Bmi-1RNAi cells were lower. After radiotherapy, the mean growth inhibition rate of CD133+/Bmi-1RNAi cells was significantly lower than CD133+ cells. In conclusion, the mPEG-CS nano-carrier is an ideal vector in gene therapy, while silencing the Bmi-1 gene can enhance the sensitivity of CD133+ tumor stem cells to chemoradiotherapy and abate their invasion ability.

Application of mPEG-CS-cRGD/Bmi-1RNAi-PTX nanoparticles in suppression of laryngeal cancer by targeting cancer stem cells.

Although surgery-based comprehensive therapy is becoming the main approach to treat laryngeal cancer, recurrence, metastasis, radiotherapy resistance and chemotherapy tolerance are still the main causes of death in patients. Targeted inhibition of laryngeal cancer stem cells has been considered as the consensus to cure laryngeal cancer. Our previous study has confirmed proto-oncogene Bmi-1 as a key regulator for self-renewal of laryngeal cancer stem cells. Targeted knockdown of Bmi-1 gene effectively inhibited the self-renewal and differentiation of laryngeal cancer stem cells, leading to the promoted sensitivity to chemotherapy including paclitaxel. However, due to off-target effects and quick degradation of the naked Bmi-1-RNAi small RNA oligo by nuclease in body fluids, it is urgently needed to develop a tumor-targeted delivery system with a protective shell. In this study, we designed and synthesized cRGD peptide-modified chitosan-polyethylene glycol slow-release nanoparticles (mPEG-CS-cRGD/Bmi-1RNAi-PTX) containing Bmi-1RNAi siRNA oligo and paclitaxel, which showed spherical in shape, 200 nm diameter in size, low cytotoxicity, strong DNA wrapping, resistance to nuclease degradation and high transfection efficiency to cells. Functional analysis indicated significant suppression of cell proliferation and migration and induction of apoptosis by the nanocomplex in laryngeal cancer cells in vitro. By application to the mouse model with laryngeal cancer, the nanocomplex inhibited tumor growth significantly in vivo. In addition, cRGD peptide, paclitaxel and Bmi-1 siRNA in the nanoparticles showed synergistic effects to suppress laryngeal cancer stem cells. In conclusion, this study not only developed a laryngeal tumor-targeted chemotherapeutic system, but also demonstrated a Bmi-1 RNAi-based chemotherapeutic strategy to inhibit cancer stem cells, having strong potential to treat laryngeal cancer patients suffering therapy resistance and/or tumor recurrence.

Metabolomic characteristics in human CD34+ hematopoietic stem/progenitor cells exposed to polystyrene nanoplastics.

Nanoplastics is a major environmental concern and may cause potential harm to organisms. Previous studies have found that exposure to nanoplastics inhibited hematopoietic function, however, the effect of polystyrene nanoplastics (PSNPs) on the human CD34+ hematopoietic stem/progenitor cells (HSPCs) and its underlying mechanism remains unknown. In this study, the toxic effects were evaluated and the metabolites changes were systematically analyzed using the metabolomics study in combination with multivariate statistical analysis in HSPCs with PSNPs treatment. The results show that PSNPs could be uptake by cells, significantly decrease cell viability and cause cell membrane damage manifested as increased LDH release in cellular supernatant. Besides, the colony formation assay shows that PSNPs exposure can inhibit the proliferation and differentiation of HSPCs. Meanwhile, we found that PSNPs disturbed the metabolic activity, including amino acids, SCFAs, organic acids, fatty acids and carbohydrates, and mainly affect citrate cycle (TCA cycle) metabolism pathway. Those findings are helpful in evaluating the toxicity mechanisms and providing guidance in the selection of potential metabolism-related biomarkers of hematopoietic damage caused by nanoplastics exposure.

A silica-polymer composite nano system for tumor-targeted imaging and p53 gene therapy of lung cancer.

In our study, a silica-polymer composite nano system (MB-NSi-p53-CS ternary complexes) composed of methylene blue-encapsulated amine-terminated silica nanoparticles (MB-NSi) and chondroitin sulfate (CS) were successfully developed for tumor-targeted imaging and p53 gene therapy of lung cancer. MB was employed as a NIR probe for in vivo imaging, MB-NSi nanoparticles were served as gene vector, while CS was applied to be a coating and targeting polymer. MB-NSi-p53-CS ternary complexes displayed nanosized diameter, effective p53 condensation ability, efficient p53 protection profile, and superior bovine serum albumin stability in vitro. Experiments on A549 cell line further revealed low cytotoxicity, high p53 transfection, and anticancer efficacy of MB-NSi-p53-CS ternary complexes. In vivo imaging and tumor targetability assays demonstrated that MB-NSi-p53-CS ternary complexes were a preferable system with desirable imaging and tumor-targeting properties.

[Olfactory acuity and improvement of olfaction after total laryngectomy].

OBJECTIVE: To test and evaluate the olfactory function of patient after total laryngectomy, seek to a practical method to ameliorate olfactory function and rise the qualitative character of these patients. METHODS: Using the T&T olfactory examination to evaluate the olfactory function of 60 cases. Four cases olfactory mucosae were observed by electron microscope. Observing relation among the remains olfaction, the time after operation and whether or not undergone the voice reconstruction. And analyse the reasons of the above hyposomnia. Using the closing-mouth and nasal out-word airflow maneuver (CNOAM) as the intervention in the patients of tracheoesophageal fistula voice reconstruction after total laryngectomy to observe the amelioration after intervention. RESULTS: It shows various degree of hyposmia and anosmia in the cases after total laryngectomy with or without tracheoesophageal fistula voice reconstruction, with significant deference (P < 0.01) compared to the normal person respectively. There are precisely correlation among the time after operation and whether or not undergone the voice reconstruction. The longer time leads to less remaining olfaction. The patients after total laryngectomy without tracheoesophageal fistula voice reconstruction have lost their olfaction thoroughly within 5 years. But for the patients after total laryngectomy with tracheoesophageal fistula voice reconstruction, they have a middle hyposmia within 5 years, with significant deference (P < 0.01) between the patients in 5 years and after 5 years. There were significant differences (P < 0.01) between the values of patients with and without tracheoesophageal fistula voice reconstruction. The ultrastructure of 4 cases of olfactory epithelium shows the apoptosis change. After the treatment of CNOAM, the remaining olfaction of most patients were improved, with significant deference (P < 0.01) compared to those before the treatment of CNOAM. CONCLUSIONS: The proceed hypofunction of olfaction may be influenced by the reform of respiratory air, the extinction of air velocity bypass the nasal cavity and the apoptosis of epithelial cells in the patients after total laryngectomy. But if we give an early intervention study such as tracheoesophageal fistula voice reconstruction and CNOAM, the olfactory function may be maintenance. During the intervention, the ending of olfactory nerves may be get uninterrupt stimulation. This may help the patients keep a better existing quality than those fail to accept the interventions.