Polydimethylsiloxane (PDMS) has emerged as a promising candidate for the dielectric layer in implantable sensors due to its exceptional biocompatibility, stability, and flexibility. This study introduces an innovative approach to produce graphene-reinforced PDMS (Gr-PDMS), where graphite powders are exfoliated into mono- and few-layer graphene sheets within the polymer solution, concurrently forming cross-linkages with PDMS. This method yields a uniformly distributed graphene within the polymer matrix with improved interfaces between graphene and PDMS, significantly reducing the percolation threshold of graphene dispersed in PDMS from 10% to 5%. As-synthesized Gr-PDMS exhibits improved mechanical and electrical properties, tested for potential use in capacitive pressure sensors. The results demonstrate an impressive pressure sensitivity up to 0.0273 kpa-1, 45 times higher than that of pristine PDMS and 2.5 times higher than the reported literature value. The Gr-PDMS showcases excellent pressure sensing ability and stability, fulfilling the requirements for implantable intracranial pressure (ICP) sensors.
Sorafenib (SF) is a first-line drug for the treatment of hepatocellular carcinoma (HCC) in clinical practice. However, acquired drug resistance tremendously limits the clinical efficacy of sorafenib in treating HCC, which has attracted great attention. PDL1 plays a crucial role in the drug resistance of HCC. Here, a codelivery system based on poly-SS-lysine modified chitosan (TAT-C-SS-P) was established and was applied to deliver sorafenib and PDL1-siRNA for synergetic HCC therapy. The successful synthesis of TAT-C-SS-P was confirmed by 1H NMR. Additionally, sorafenib and PDL1-siRNA were successfully transported into the cells as the decreased expression of VEGF and PD-L1 by administrated with TAT-C-SS-P@SF@ PDL1-siRNA. Simultaneously, the expression of pro-apoptosis proteins cyt-c and Bax was prominently augmented, whereas the expression of anti-apoptosis protein Bcl-2 was decreased. The reduced expression of PDL1 resulted in the downregulation of P-GP and MRP1, which contributed to more sorafenib aggregation in tumor cells. Moreover, TAT-C-SS-P@PDL1-siRNA@SF efficiently promotes apoptosis of HepG2-SI cells, as the apoptosis rate rised to 73 %. A sorafenib-insensitive model was established to evaluate in vivo antitumor effect of TAT-C-SS-P@PDL1-siRNA@SF. TAT-C-SS-P@PDL1-siRNA@SF showed a tumor inhibition rate of 90.2 ± 3.5 % and no significant decrease in body weight. Taken together, our study provided compelling evidence that TAT-C-SS-P@PDL1-siRNA@SF has great potential application in the treatment of HCC clinically.
Carcinoma, Hepatocellular , Chitosan , Liver Neoplasms , Humans , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/metabolism , Sorafenib/pharmacology , Chitosan/pharmacology , Lysine/pharmacology , RNA, Small Interfering , Liver Neoplasms/drug therapy , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , B7-H1 Antigen , Cell Line, Tumor , Apoptosis , Drug Resistance, Neoplasm/genetics , Cell Proliferation
BACKGROUND: There is an increasing need for thoracic medicine specialists to master preoperative localizations after high rates of sub-centimeter nodules have been positively screened by low-dose CT. The Laser Angle Guide Assembly® (LAGA), an innovative angle reference device for CT-guided pulmonary invasive procedures, has been developed to safely and efficiently aid in the performance of preoperative CT-guided localizations (POCTGL). METHODS: The clinical and localization data of patients who received LAGA-assisted POCTGL for pulmonary nodules between May 2015 and June 2018 were collected and analyzed. RESULTS: One hundred and eighty-seven patients with 266 pulmonary nodules received LAGA-assisted POCTGL. The number of lung nodules localized for one surgery ranged from 1 to 5, with >1 for 22.1% of the surgeries. The median nodule size was 6 mm. A hookwire was inserted in 32 (12%) of the nodules. Most (83.1%) of the localizations were completed with a single puncture. The median angle was 18 degrees. The median and maximum depths of the nodule to pleura were 12 and 60 mm, respectively. The median procedure time was 19 minutes. The successful targeting and field targeting rates were 100% and 98.1%, respectively. Pneumothorax was noted in 17 (6.4%) localizations that did not require chest drainage. The multivariable analyses for pneumothorax showed odds ratios of 2.4 (95% confidence interval, 1.2-4.9) for puncture times/nodule and 10.1 (95% confidence interval, 2.3-41.7) for tumors adjacent to the fissure, respectively. There was no incidence of hookwire migration. CONCLUSIONS: LAGA enhanced the precision of POCTGL by optimizing targeting precision and decreasing repeated punctures, which minimized complications, such as pneumothorax.
Computed tomography (CT)-guided lung procedures such as preoperative localizations, biopsies, and ablations are associated with morbidity even mortality. Often, the puncture angle is determined by the 'experienced hand' without a precise guide. We describe here the Laser Angle Guide Assembly® to direct and steer the puncture angles precisely. It decreases procedure-related complications, saves time, reduces costs, avoids repeated punctures, and minimizes radiation exposures.
