Surface-assisted laser desorption/ionisation time-of-flight mass spectrometry (SALDI-TOF-MS) might be the method of choice for the analysis of low mass molecules (less than
m
/
z
500). Titanium ...dioxide (TiO
2
) nanocrystals as a substrate for SALDI-TOF-MS improve the reproducibility of the signal intensities and prevent the fragmentation of some molecules upon laser irradiation, as we have previously shown. In addition, variously shaped and sized TiO
2
nanocrystals/substrates for SALDI-MS could be used for quantification of small molecules, which are otherwise difficult to detect with the assistance of organic matrices. TiO
2
-assisted LDI-MS spectra could be acquired with excellent reproducibility and repeatability and with low detection limit. In the current study, we analysed the spectra of dexasone, citric acid, vitamin E and vitamin A acquired with TiO
2
nanocrystals of various shapes and dimensions, i.e. the colloidal TiO
2
nanoparticles (TiO
2
NPs), TiO
2
prolate nanospheroids (TiO
2
PNSs) and TiO
2
nanotubes (TiO
2
NTs). Various shapes and dimensions of substrates were used since these factors determine desorption and ionisation processes. The homogeneity on the target plate was compared based on signal-to-noise values of peaks of interest of analysed molecules as well as the within-day and day-to-day repeatability. In summary, the obtained results show that the applicability of individual TiO
2
nanocrystals depends on the analyte. Signals which are acquired with the assistance of TiO
2
PNSs have the highest sensitivity and reproducibility (the smallest standard deviation), even compared with those in the LDI mode. This implies that TiO
2
PNSs could also be suitable for quantitative analyses of small molecules.
The literature data emphasize that nanoparticles might improve the beneficial effects of near-infrared light (NIR) on wound healing. This study investigates the mechanisms of the synergistic wound ...healing potential of NIR light and silver metal-organic frameworks combined with nitrogen- and sulfur-doped carbon dots (AgMOFsN-CDs and AgMOFsS-CDs, respectively), which was conducted by testing the fibroblasts viability, scratch assays, biochemical analysis, and synchrotron-based Fourier transform infrared (SR-FTIR) cell spectroscopy and imaging. Our findings reveal that the combined treatment of AgMOFsN-CDs and NIR light significantly increases cell viability to nearly 150% and promotes cell proliferation, with reduced interleukin-1 levels, suggesting an anti-inflammatory response. SR-FTIR spectroscopy shows this combined treatment results in unique protein alterations, including increased α-helix structures and reduced cross-β. Additionally, protein synthesis was enhanced upon the combined treatment. The likely mechanism behind the observed changes is the charge-specific interaction of N-CDs from the AgMOFsN-CDs with proteins, enhanced by NIR light due to the nanocomposite's optical characteristics. Remarkably, the complete wound closure in the in vitro scratch assay was achieved exclusively with the combined NIR and AgMOFsN-CDs treatment, demonstrating the promising application of combined AgMOFsN-CDs with NIR light photodynamic therapy in regenerative nanomedicine and tissue engineering.
In this work it has been shown that both the laser desorption/ionization mass
spectrometry (LDI MS) and the matrix assisted laser desorption/ionization
time-of-flight mass spectrometry (MALDI TOF MS) ...are the simple and quick
methods for determination of relative natural isotopic distribution of lead.
The analysis of metal salts with these approaches does not require any
time-consuming preparation of samples: a single run can take only a minute,
and numerous information can be obtained. Results obtained in this work show
that chosen matrix has no negative effect on quantitative determination of
lead isotopes and support once more the applicability of MALDI TOF MS for
lead isotope distribution determination in the sample, and accuracy of data
obtained. Additionally, the generation of PbnOn and PbnOn-1 (n: 2 - 6)
clusters have been successfully achieved in the positive mode, using the both
LDI and MALDI methods. All stoichiometries were confirmed using isotopic
pattern modelling.
This paper presents optimization of matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometer (MS) instrumental parameters for the analysis of ...chloro(2,2'',2"-terpyridine)palladium(II) chloride dihydrate complex applying design of experiments methodology (DoE). This complex is of interest for potential use in the cancer therapy. DoE methodology was proved to succeed in optimization of many complex analytical problems. However, it has been poorly used for MALDI-TOF-MS optimization up to now. The theoretical mathematical relationships which explain the influence of important experimental factors (laser energy, grid voltage and number of laser shots) on the selected responses (signal to noise ? S/N ratio and the resolution ? R of the leading peak) is established. The optimal instrumental settings providing maximal S/N and R are identified and experimentally verified.
Surface-assisted laser desorption/ionisation time-of-flight mass spectrometry (SALDI-TOF-MS) might be the method of choice for the analysis of low mass molecules (less than m/z 500). Titanium dioxide ...(TiO.sub.2) nanocrystals as a substrate for SALDI-TOF-MS improve the reproducibility of the signal intensities and prevent the fragmentation of some molecules upon laser irradiation, as we have previously shown. In addition, variously shaped and sized TiO.sub.2 nanocrystals/substrates for SALDI-MS could be used for quantification of small molecules, which are otherwise difficult to detect with the assistance of organic matrices. TiO.sub.2-assisted LDI-MS spectra could be acquired with excellent reproducibility and repeatability and with low detection limit. In the current study, we analysed the spectra of dexasone, citric acid, vitamin E and vitamin A acquired with TiO.sub.2 nanocrystals of various shapes and dimensions, i.e. the colloidal TiO.sub.2 nanoparticles (TiO.sub.2 NPs), TiO.sub.2 prolate nanospheroids (TiO.sub.2 PNSs) and TiO.sub.2 nanotubes (TiO.sub.2 NTs). Various shapes and dimensions of substrates were used since these factors determine desorption and ionisation processes. The homogeneity on the target plate was compared based on signal-to-noise values of peaks of interest of analysed molecules as well as the within-day and day-to-day repeatability. In summary, the obtained results show that the applicability of individual TiO.sub.2 nanocrystals depends on the analyte. Signals which are acquired with the assistance of TiO.sub.2 PNSs have the highest sensitivity and reproducibility (the smallest standard deviation), even compared with those in the LDI mode. This implies that TiO.sub.2 PNSs could also be suitable for quantitative analyses of small molecules.
Surface-assisted laser desorption/ionisation time-of-flight mass spectrometry (SALDI-TOF-MS) might be the method of choice for the analysis of low mass molecules (less than m/z 500). Titanium dioxide ...(TiO sub(2)) nanocrystals as a substrate for SALDI-TOF-MS improve the reproducibility of the signal intensities and prevent the fragmentation of some molecules upon laser irradiation, as we have previously shown. In addition, variously shaped and sized TiO sub(2) nanocrystals/substrates for SALDI-MS could be used for quantification of small molecules, which are otherwise difficult to detect with the assistance of organic matrices. TiO sub(2)-assisted LDI-MS spectra could be acquired with excellent reproducibility and repeatability and with low detection limit. In the current study, we analysed the spectra of dexasone, citric acid, vitamin E and vitamin A acquired with TiO sub(2) nanocrystals of various shapes and dimensions, i.e. the colloidal TiO sub(2) nanoparticles (TiO sub(2) NPs), TiO sub(2) prolate nanospheroids (TiO sub(2) PNSs) and TiO sub(2) nanotubes (TiO sub(2) NTs). Various shapes and dimensions of substrates were used since these factors determine desorption and ionisation processes. The homogeneity on the target plate was compared based on signal-to-noise values of peaks of interest of analysed molecules as well as the within-day and day-to-day repeatability. In summary, the obtained results show that the applicability of individual TiO sub(2) nanocrystals depends on the analyte. Signals which are acquired with the assistance of TiO sub(2) PNSs have the highest sensitivity and reproducibility (the smallest standard deviation), even compared with those in the LDI mode. This implies that TiO sub(2) PNSs could also be suitable for quantitative analyses of small molecules.
In this work, the performances of two ionic liquid matrices (ILMs) with the same ammonium counterpart for mass spectrometric analysis of the insoluble and soluble sucralfate were compared. ...Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) was performed assisted by the butylammonium salts of α-cyano-hydroxycinnamic acid (CHCAB) and 2,5-dihydroxybenzoic acid (DHBB). CHCAB has a higher IE than DHBB, but better optical properties. CHCAB is more suitable for the analysis of sucralfate, although molecular ions of both compounds were detectable only with low intensities. Thus, optical properties of ILMs are crucial to enhance the sensitivity of MALDI MS detection of polysulfated oligosaccharides.
We predicted the protein therapeutic targets specific to a Ru-based potential drug and its combination with pristine and N-doped carbon dot drug delivery systems, denoted as RuCN/CDs and RuCN/N-CDs. ...Synchrotron-based FTIR microspectroscopy (µFTIR) in addition to bioinformatics data on drug structures and protein sequences were applied to assess changes in the protein secondary structure of A2780 cancer cells. µFTIR revealed the moieties of the target proteins’ secondary structure changes only after the treatment with RuCN and RuCN/N-CDs. A higher content of α-helices and a lower content of β-sheets appeared in A2780 cells after RuCN treatment. Treatment with RuCN/N-CDs caused a substantial increase in parallel β-sheet numbers, random coil content, and tyrosine residue numbers. The results obtained suggest that the mitochondrion-related proteins NDUFA1 and NDUFB5 are affected by RuCN either via overexpression or stabilisation of helical structures. RuCN/N-CDs either induce overexpression of the β-sheet-rich protein NDUFS1 and affect its random coil structure or interact and stabilise its structure via hydrogen bonding between -NH2 groups from N-CDs with protein C=O groups and –OH groups of serine, threonine, and tyrosine residues. The N-CD nanocarrier tunes this drug’s action by directing it toward a specific protein target, changing this drug’s coordination ability and inducing changes in the protein’s secondary structures and function.
This paper presents optimization of matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometer (MS) instrumental parameters for the analysis of ...chloro(2,2',2"-terpyridine)palladium(II) chloride dihydrate complex applying design of experiments methodology (DoE). This complex is of interest for potential use in the cancer therapy. DoE methodology was proved to succeed in optimization of many complex analytical problems. However, it has been poorly used for MALDI-TOF-MS optimization up to now. The theoretical mathematical relationships which explain the influence of important experimental factors (laser energy, grid voltage and number of laser shots) on the selected responses (signal to noise-S/N ratio and the resolution-R of the leading peak) is established. The optimal instrumental settings providing maximal S/N and R are identified and experimentally verified. Keywords: MALDI-TOF-MS, design of experiments (DoE), optimization, metallo-drugs. IZVOD (Naucni rad) U okviru ovog rada ispitane su mogucnosti koriscenja matematicke metodologije dizajniranja eksperimenta (Design of Experiments (DoE) methodology) za optimizaciju instrumentalnih parametara kod spektroskopije masa sa laserskom desorpcijom i jonizacijom uz pomoc "matrice" (MALDI-MS), za analizu Pd(terpy)ClCl x 2H.sub.2O kompleksa. Navedeni metalni kompleks predstavlja potencijalni lek u antikancer terapiji, tako da povecanje efikasnosti razvoja metoda njegove analize/karakterizacije, kao i uspostavljanje uslova za analizu proizvoda njegove interakcije sa biomolekulima, predstavljaju vazan zadatak. DoE metodologija obezbeduje sistematsko ispitivanje uticaja izdvojenih instrumentalnih parametara (predstavljaju ulazne promenljive ili faktore) na kljucne karakteristike kvalitetnog spektra (tzv. "odgovor") u cilju dobijanja pouzdane identifikacije. Eksperimentalno, spektar je poznat samo na tacno odabranim vrednostima instrumentalnih parametra (u odredenom rangu), ali se ne dobijaju informacije o spektru za vrednosti izmedu pomenutih parametra. Ispitivanje uticaja vrednosti instrumentalnih parametara, izmedu onih vec ispitanih, na kvalitet spektra, eksperimentalno predstavlja izuzetno komplikovan postupak, zbog velikog broja kombinacija. DoE metodologija uspostavlja matematicke relacije izmedu odabranih faktora i "odgovora", na osnovu malog broja pazljivo isplaniranih eksperimenata (Box-Behnken design-pristup). U analitickoj hemiji, ova metodologija uspesno je primenjena za optimizaciju hemijskih faktora kod hromatografskih, elektroana-litickih, termogravimetrijskih i drugih metoda. DoE pristup, do sada, primenjen je za optimizaciju instrumentalnih parametara u slucaju, atomske apsorpcione spektrometrije sa grafitnom kivetom, indukovano kuplovane plazme opticke emisione spektrometrije, indukovano kuplovane plazme spektrometrije masa, kod MALDI spektrometrije masa, ali ne za detekciju kompleksnih jedinjenja. Analiza kompleksa prelaznih metala uz pomoc MALDI-TOF-MS je poseban izazov zbog velikog broja signala koji poticu od izotopa prelaznih metala, tako da je rezolucija koju treba postici od velikog znacaja. Ulazni faktori (promenljive) u ovom radu bili su: intenzitet lasera, broj udaraca lasera i napon na "gridu", a vazne karakteristike spektara, kao sto su odnos signal/sum i rezolucija, predstavljaju trazeni "odgovor". Raspon vrednosti ulaznih faktora odreden je na osnovu preliminarnih eksperimentalnih podataka. Rezultati su pokazali da vrednosti odnosa signal/sum pokazuju jaku kvadratnu zavisnost od intenziteta lasera i umereno zavise od napona na "gridu" i broja udaraca lasera. Rezolucija linearno zavisi od intenziteta lasera i napona na "gridu". Medu nekoliko potencijalnih resenja izabrani inetenzitet lasera od 1220, napon na "gridu" od 79% i 360 udaraca lasera predstavljaju optimalne uslove za dobijanje kvalitetnog spektra Pd(terpy)ClCl x 2H.sub.2O kompleksa, sto je kasnije i eksperimentalno potvrdeno. Kljucne reci: MALDI-TOF-MS * DoE metodologija * Optimizacija * Lekovi na bazi metala
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