ABSTRACT
The rapid proliferation of new psychoactive substances (NPS) poses significant challenges to conventional mass-spectrometry-based identification methods due to the absence of reference spectra for these emerging substances. This paper introduces PS2MS, an AI-powered predictive system designed specifically to address the limitations of identifying the emergence of unidentified novel illicit drugs. PS2MS builds a synthetic NPS database by enumerating feasible derivatives of known substances and uses deep learning to generate mass spectra and chemical fingerprints. When the mass spectrum of an analyte does not match any known reference, PS2MS simultaneously examines the chemical fingerprint and mass spectrum against the putative NPS database using integrated metrics to deduce possible identities. Experimental results affirm the effectiveness of PS2MS in identifying cathinone derivatives within real evidence specimens, signifying its potential for practical use in identifying emerging drugs of abuse for researchers and forensic experts.
Subject(s)
Deep Learning , Illicit Drugs , Chromatography, Liquid/methods , Psychotropic Drugs/analysis , Mass Spectrometry/methods , Illicit Drugs/analysis , Substance Abuse Detection/methodsABSTRACT
Knowing the stability of drugs is important to ensure accurate and reliable results of drug concentrations. This study evaluated the stability of ten new psychoactive substances (NPSs) in urine and methanol/water at different storage temperatures. Quantitative analyses were performed using liquid chromatography-tandem mass spectrometry. Three replicates of each storage condition were analyzed at day 0 and after 7, 14-, 30-, 60-, and 90 days with storage at +25°C, +4°C, and -20°C. For each analyte, the percent difference at each time interval from day 0 was calculated for each storage condition. Para-methoxyamphetamine (PMA), para-methoxymethamphetamine (PMMA), deschloroketamine (DCK), and 2-fluorodeschloroketamine (2-FDCK) were stable in urine, even when stored for 90-day periods at various temperatures. For synthetic cathinones, the concentrations declined over time at room temperature (+25°C) in urine but were relatively stable in methanol solvent with 0.1% formic acid. The significant degradation was found at +25°C, and the most excellent stability was shown by samples stored at -20°C. Phenethylamines (PMA and PMMA) and ketamine substitutes (DCK and 2-FDCK) were relatively more stable than synthetic cathinones (mephedrone, butylone, pentylone, ephylone, 4-MEAPP, and eutylone).
ABSTRACT
The blocking of programmed death-ligand 1 (PD-L1) in tumor cells represents a powerful strategy in cancer immunotherapy. Using viral vectors to deliver the cargo for inactivating the PD-L1 gene could be associated with host cell genotoxicity and concomitant immune attack. To develop an alternative safe gene delivery method, we designed a unique combination for miRNA34a delivery using a transgene carrier in the form of iron oxide magnetic nanoparticles (IONPs) via magnetofection to downregulate PD-L1 expression in cancer cells. We synthesized IONPs of multiple shapes (IONRs (iron oxide nanorods), IONSs (iron oxide nanospheres), and ITOHs (iron oxide truncated octahedrons)), surface-functionalized with polyethyleneimine (PEI) using the ligand exchange method, as gene delivery systems. Under the guidance of an external magnetic field, PEI@IONPs loaded with plasmid DNA (DNA/PEI@IONPs) encoding GFP showed high transfection efficiency at different weight ratios and time points in A549 and MDA-MB-231 cells. Additionally, the DNA/PEI@IONPs with miRNA34a inserts under a static magnetic field resulted in significant knockdown of the PD-L1 gene, as demonstrated via immunoblotting of the PD-L1 protein. Among the three shapes of IONPs, IONRs showed the highest PD-L1 knockdown efficiency. The genetic expression of miRNA34a was also studied using qPCR and it showed high expression of miRNA in cells treated with PEI@IONRs. Flow cytometry and a live/dead assay confirmed apoptosis after transfection with miRNA34a. To conclude, in this paper, a promising transgene carrier with low cost, negligible cytotoxicity, and high transfection efficiency has been successfully established for miRNA gene delivery in the context of cancer immunotherapy.
ABSTRACT
BACKGROUND: Potassium channels have been reported to be involved in the proliferation of many types of cells, including tumor cells. The overexpression of the K+ channel and related channel activity are involved in the neoplastic process. METHODS: We examined the expression of an A-type voltage-gated K+ channel, Kv3.4, in oral squamous cell carcinoma (OSCC) and esophageal squamous cell carcinoma (ESCC) compared with non-cancerous matched tissue (NCMT) using RT-PCR analysis. In addition, administration of an A-type K+ channel blocker, 4-aminopyridine (4-AP), and an antisense oligodeoxynucleotide (ODN) directed specifically against Kv3.4 were performed to identify the involvement of Kv3.4 in the growth of OSCC cells. RESULTS: A significantly increase in the frequency of Kv3.4 mRNA expression was identified in OSCC (64%) compared to corresponding NCMT (29%) (P = 0.05). The increase of Kv3.4 mRNA expression was also eminent in ESCC. Growth of OSCC cells was significantly inhibited by 4-AP in a dose-dependent manner at different time point of treatment. In OECM-1 OSCC cells, a significant growth inhibition was noted in antisense ODN-treated cells compared to control cells. CONCLUSION: We provide novel evidences of the increase of Kv3.4 mRNA expression in OSCC. The abrogation of Kv3.4 inhibits the growth of OSCC cells.
