Multigrid MALDI mass spectrometry imaging (mMALDI MSI).

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) is an important technique for the spatially resolved molecular analysis of tissue sections. The selection of matrices influences the resulting mass spectra to a high degree. For extensive and simultaneous analysis, the application of different matrices to one tissue sample is desirable.

High resolution mass spectrometry imaging reveals the occurrence of phenylphenalenone-type compounds in red paracytic stomata and red epidermis tissue of Musa acuminata ssp. zebrina cv. 'Rowe Red'.

The banana epidermis and in particular their stomata are conducive sites for the penetration of pathogenic fungi which can severely limit global banana production. The red pseudostem of the ornamental banana Musa acuminata ssp. zebrina cv.

COCONUT—An Efficient Tool for Estimating Copolymer Compositions from Mass Spectra.

The accurate characterization of synthetic polymer sequences represents a major challenge in polymer science. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is frequently used for the characterization of copolymer samples. We present the COCONUT software for estimating the composition distribution of the copolymer.

Phenalenone-type phytoalexins mediate resistance of banana plants (Musa spp.) to the burrowing nematode Radopholus similis.

The global yield of bananas-one of the most important food crops-is severely hampered by parasites, such as nematodes, which cause yield losses up to 75%. Plant-nematode interactions of two banana cultivars differing in susceptibility to Radopholus similis were investigated by combining the conventional and spatially resolved analytical techniques (1)H NMR spectroscopy, matrix-free UV-laser desorption/ionization mass spectrometric imaging, and Raman microspectroscopy. This innovative combination of analytical techniques was applied to isolate, identify, and locate the banana-specific type of phytoalexins, phenylphenalenones, in the R.

Drugs as matrix to detect their own drug delivery system of PEG-b-PCL block copolymers in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Rationale: The fate of drug delivery systems (DDSs) in vivo is a widely discussed question. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is an important tool to localize proteins and small compounds in many different tissues. This basic study was performed as an aid to obtain spatial information on DDSs in the future.

Star-shaped drug carriers for doxorubicin with POEGMA and POEtOxMA brush-like shells: a structural, physical, and biological comparison.

The synthesis of amphiphilic star-shaped poly(ε-caprolactone)-block-poly(oligo(ethylene glycol)methacrylate)s ([PCL(18)-b-POEGMA](4)) and poly(ε-caprolactone)-block-poly(oligo(2-ethyl-2-oxazoline)methacrylate)s ([PCL(18)-b-POEtOxMA](4)) is presented. Unimolecular behavior in aqueous systems is observed with the tendency to form loose aggregates for both hydrophilic shell types. The comparison of OEGMA and OEtOxMA reveals that the molar mass of the macromonomer in the hydrophilic shell rather than the mere length is the crucial factor to form an efficiently stabilizing hydrophilic shell.

4-Deoxyaurone formation in Bidens ferulifolia (Jacq.) DC.

The formation of 4-deoxyaurones, which serve as UV nectar guides in Bidens ferulifolia (Jacq.) DC., was established by combination of UV photography, mass spectrometry, and biochemical assays and the key step in aurone formation was studied.

Tandem mass spectrometry of poly(ethylene imine)s by electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI).

In this contribution, linear poly(ethylene imine) (PEI) polymers, which are of importance in gene delivery, are investigated in detail by using electrospray ionization-quadrupole-time of flight (ESI-Q-TOF) and matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS). The analyzed PEIs with different end groups were synthesized using the polymerization of substituted 2-oxazoline via a living cationic ring-opening polymerization (CROP) and a subsequent hydrolysis under acidic conditions. The main goal of this study was to identify linear PEI polymers in a detailed way to gain information about their fragmentation pathways.

Poly(ethylene glycol) in drug delivery: pros and cons as well as potential alternatives.

Poly(ethylene glycol) (PEG) is the most used polymer and also the gold standard for stealth polymers in the emerging field of polymer-based drug delivery. The properties that account for the overwhelming use of PEG in biomedical applications are outlined in this Review. The first approved PEGylated products have already been on the market for 20 years.

Matrix-free UV-laser desorption/ionization (LDI) mass spectrometric imaging at the single-cell level: distribution of secondary metabolites of Arabidopsis thaliana and Hypericum species.

The present paper describes matrix-free laser desorption/ionisation mass spectrometric imaging (LDI-MSI) of highly localized UV-absorbing secondary metabolites in plant tissues at single-cell resolution. The scope and limitations of the method are discussed with regard to plants of the genus Hypericum. Naphthodianthrones such as hypericin and pseudohypericin are traceable in dark glands on Hypericum leaves, placenta, stamens and styli; biflavonoids are also traceable in the pollen of this important phytomedical plant.

Monomeric pheophorbide(a)-containing poly(ethyleneglycol-b-epsilon-caprolactone) micelles for photodynamic therapy.

Incorporation of unaggregated monomeric molecules of pheophorbide(a) into micelles of poly(ethyleneoxide-b-epsilon-caprolactone) has been characterized by fluorescence spectroscopy, dynamic light scattering, transmission electron microscopy and asymmetric flow field flow fractionation. It was shown that the method used leads to 20 nm micelles, corresponding to approximately 200 molecules of polymer and 4 molecules of monomeric pheophorbide(a) per nano-object which was able to generate (1)O(2) in the medium. They have been used thereafter as nanocarriers for photosensitizers in photodynamic therapy against cancer cells.

Characterization of different poly(2-ethyl-2-oxazoline)s via matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) coupled with CID (collision-induced dissociation) has been used for the detailed characterization of two poly(2-ethyl-2-oxazoline)s as part of a continuing study of synthetic polymers by MALDI-TOF MS/MS. These experiments provided information about the variety of fragmentation pathways for poly(oxazoline)s. It was possible to show that, in addition to the eliminations of small molecules, like ethene and hydrogen, the McLafferty rearrangement is also a possible fragmentation route.

Mesoionic bora-tetraazapentalenes--fully reversible two step redox systems.

Bora-tetraazapentalenes have been synthesised and characterized; the radical anion shows an unusual thermodynamic stability (semiquinone formation constants K(SEM) of ca. 10(14)).