Multi-panel drugs detection in human serum for personalized therapy.

This work focuses on P450 biosensors based on multiwalled carbon nanotubes (MWCNT) and different cytochrome isoforms: 3A4, 2B4, 2C9. The proposed biosensors exhibit enhanced sensitivities and decreased detection limits thanks to carbon nanotubes. The MWCNT structuring improves the sensitivity from 5.1 to 20.5 nA/mM mm(2) in case of CYP2B4-mediated Benzphetamine detection, from 0.26 to 0.63 nA/µM mm(2) in case of CYP3A4-mediated Cyclophosphamide detection, and from 0.11 to 0.25 nA/µM mm(2) in case of CYP2C9-mediated Naproxen detection. By using MWCNT, the limit of detection was enhanced from 59 to 12 µM in case of Cyclophosphamide and from to 187 to 82 µM in case of Naproxen. This makes possible the drug detection in human serum within the pharmacological range. In the paper, a new mathematical model is also proposed to succeed in discriminating different drug contributions in a mixture containing both Cyclophosphamide and Dextromethorphan or combining Naproxen and Flurbiprofen. Data analysis shows variations in reduction peaks that are dependent on the drug ratio, and that are consistent with competitive kinetics of substrates. This new approach enables multiple drug detection and opens the way to possible applications in personalized therapy.

Direct high-performance liquid chromatographic separation of the enantiomers of an aromatic amine and four aminoalcohols using polysaccharide chiral stationary phases and acidic additive.

The HPLC enantiomeric separation of N-benzyl-alpha-methyl-benzylamine, phenylalaninol, tryptophanol, 2 (diphenylhydroxymethyl)pyrrolidine, and isoproterenol was accomplished in the normal-phase mode using two polysaccharide-derived chiral stationary phases (CSPs) and various n-hexane/2-propanol mobile phases with acidic (TFA) or basic (DEA) additive. The compounds were separated without any derivatization and separation factor range between 2.09 and 1.09 with resolution factor 3.4 and 0.4, respectively. The best separation of the enantiomers of the amine was achieved on amylose tris (3, 5-dimethylphenylcarbamate) CSP with TFA additive in the mobile phase; in acidic conditions, instead, the best enantioseparation of the aminoalcohols was achieved on cellulose tris (3, 5-dimethylphenilcarbamate). A long equilibration time of the CSP when switching from an undoped mobile phase to a doped one is required to obtain reproducible results.