Mareike Müller

University of Siegen · Department of Chemistry and Biology

A systematic study on the surface-initiated polymerization of di(ethylene glycol) methyl ether methacrylate (DEGMA) by atom transfer radical polymerization (ATRP) from glass, silicon, titanium as well as tissue culture polystyrene (TCPS) is reported in an attempt to expand the known thermoresponsive poly(di(ethylene glycol) methyl ether methacrylat...

Nine 6‐aryl‐substituted harmanium derivatives were synthesized by Suzuki‐Miyaura coupling of 6‐bromoharmane with arylboronic acids and subsequent N2‐benzylation. Depending on the substitution pattern of the aryl group the emission maxima cover a range between λfl=445 and 529 nm with quantum yields of Φfl=<0.01–0.92. The interactions with duplex DNA...

The development of new approaches for the treatment of the increasingly antibiotic-resistant pathogen Pseudomonas aeruginosa was targeted by enhancing the effect of local antimicrobial photodynamic therapy (aPDT) using poly(ethylene glycol)-block-poly(lactic acid) (PEG114-block-PLAx) nanocarriers that were loaded with a ruthenium-based photosensiti...

DNA‐sensitive fluorescent light‐up probes based on berberine are presented. This biogenic fluorophore was chosen as central unit to use its potential biocompatibility and its DNA‐binding properties. To provide predictable fluorescence quenching in aqueous solution and a fluorescence light‐up effect upon DNA binding, aryl substituents were attached...

The fabrication, characterization and application of a nanoporous Silicon Rugate Filter (pSiRF) loaded with an enzymatically degradable polymer is reported as a bare eye detection optical sensor for enzymes of pathogenic bacteria, which is devoid of any dyes. The nanopores of pSiRF were filled with poly(lactic acid) (PLA), which, upon enzymatic deg...

Antimicrobial photodynamic therapy (aPDT) depends on a variety of parameters notably related to the photosensitizers used, the pathogens to target and the environment to operate. In a previous study using a series of Ruthenium(II) polypyridyl ([Ru(II)]) complexes, we reported the importance of the chemical structure on both their photo-physical/phy...

The rapid and selective detection of bacterial contaminations and bacterial infections in a non-laboratory setting using advanced sensing materials holds the promise to enable robust point-of-care tests and rapid diagnostics for applications in the medical field as well as food safety. Among the various possible analytes, bacterial enzymes have bee...

Women with cystic fibrosis (CF) have a significantly lower life expectancy compared to men, which is indicated by an earlier impairment of lung function due to chronic colonization with biofilm formed by Pseudomonas aeruginosa. There is growing evidence that blood serum concentrations of the steroid sex hormone estradiol (E2) correlate with the occ...

Nanomedicine strategies were first adapted and successfully translated to clinical application for diseases, such as cancer and diabetes. These strategies would no doubt benefit unmet diseases needs as in the case of leishmaniasis. The latter causes skin sores in the cutaneous form and affects internal organs in the visceral form. Treatment of cuta...

We report on the fabrication and characterization of color-encoded chitosan hydrogels for the rapid, sensitive and specific detection of bacterial enzymes as well as the selective detection of a set of tested bacteria through characteristic enzyme reactions. These patterned sensor hydrogels are functionalized with three different colorimetric enzym...

Antimicrobial photodynamic therapy (aPDT) has become a fundamental tool in modern therapeutics, notably due to the expanding versatility of photosensitizers (PSs) and the numerous possibilities to combine aPDT with other antimicrobial treatments to combat localized infections. After revisiting the basic principles of aPDT, this review first highlig...

The dye 3‐(4‐(N,N‐dimethylamino)phenyl)naphtho[1,2‐b]quinolizinium was synthesized by means of a Suzuki–Miyaura reaction in good yield, and its binding properties with duplex DNA, quadruplex DNA (G4‐DNA), RNA, and bovine serum albumin (BSA) were investigated by photometric, fluorimetric and polarimetric titrations and DNA denaturation analysis. The...

Despite decades of biomedical advances, the colonization of implant devices with bacterial biofilms is still a leading cause of implant failure. Clearly, new strategies and materials that suppress both initial and later stage bacterial colonization are required in this context. Ideal would be the implementation of a bactericidal functionality in th...

The development of efficient and sustainable microbial inactivation approaches is an important objective. Dense-Phase-Carbon-Dioxide and related approaches, which utilize high pressure CO2, were reported to be feasible methods. However, a major challenge is the enhancement of sustainability and economic viability by reducing the necessary temperatu...

There is a growing demand for rapid and sensitive detection approaches for pathogenic bacteria that can be applied by non-specialists in non-laboratory field settings. Here, the detection of the typical E. coli enzyme β-glucuronidase using a chitosan-based sensing hydrogel-coated paper sensor and the detailed analysis of the reaction kinetics, as d...

The non-fluorescent 9-nitrobenzo[b]quinolizinium is readily reduced by nitroreductase to a fluorescent reaction product. The resulting light-up effect enables the selective detection of nitro-reductase activity in vitro and in Escherichia coli...

Many tumors develop resistance to most of the apoptosis-based cancer therapies. In this sense targeting non-apoptotic forms of cell death including necroptosis, autophagy and ferroptosis may have therapeutic benefits in apoptosis-defective cancer cells. Nanomaterials have shown great advantages in cancer treatment owing to their unique characterist...

The enhancement of standard dense phase carbon dioxide (DPCD) pasteurization by additional mechanical effects was assessed in this work. These effects were induced during pasteurization by the sudden depressurization in a narrow minitube. The high flow velocities, moderate pressures (40–80 bar) and low temperatures (25–45 °C) lead to intense degasi...

Herein, we demonstrate a combined fluorescent probe/shape encoded hydrogel strategy for the fast, sensitive and selective detection of bacterial species via their characteristic enzymes. A polyvinyl alcohol (PVA) hydrogel loaded with the fluorescent probe N,N'-(3-oxo-3H-spiro[isobenzofuran-1,9'-xanthene]-3',6'-diyl)bis(2,2,3,3,3-pentafluoropropanam...

Alzheimer’s disease (AD) is a multifactorial neurodegenerative disease which leads to progressive dysfunction of cognition, memory and learning in elderly people. Common therapeutic agents are not only inadequate to suppress the progression of AD pathogenesis but also produce deleterious side effects; hence development of alternative therapies is r...

The combination of styryl dye properties with the acidity and strong photoacidity of the 2,2′‐[(1′′‐hydroxy‐4′′‐methyl‐(E)‐2′′,6′′‐phenylene)]‐bisquinolizinium enables the detection of DNA by distinct absorption and emission color changes and the fluorimetric detection of DNA in cells with epifluorescence and confocal fluorescence microscopy. image

The selective detachment of undifferentiated human induced pluripotent stem (iPS) cells from a thermal release coating, fabricated from a tailored poly(di(ethylene glycol) methyl ether methacrylate) (PDEGMA) homopolymer layer on gold, is reported. By exploiting the mild, thermally triggered release of iPS cell colonies in the absence of any releasi...

The selective detachment of undifferentiated human induced pluripotent stem (iPS) cells from a thermal release coating, fabricated from a tailored poly(di(ethylene glycol) methyl ether methacrylate) (PDEGMA) homopolymer layer on gold, is reported. By exploiting the mild, thermally triggered release of iPS cell colonies in the absence of any releasi...

Ultra-thin thermoresponsive poly(di(ethylene glycol) methyl ether methacrylate) (PDEGMA) homopolymer layers are reported as a novel platform for label-free temperature-stimulated cell separation from a co-culture of eukaryotic cell lines. Pancreatic tumor cells (PaTu 8988t) and fibroblasts (NIH 3T3) were shown to attach and proliferate on PDEGMA la...

Fabrication, characterization, and application of micropatterned one-component poly(di(ethylene glycol)methyl ether methacrylate) (PDEGMA) brushes for monolayer cell and spheroid culture and temperature-triggered release are reported. Micropatterns of various shapes and sizes were designed to possess a unique functionality imparted by thermorespons...

In this work, patterned β‐GUS sensing chitosan hydrogels functionalized with three different colorimetric substrates were fabricated for the multiplexed detection of the enzyme β‐glucuronidase (β‐GUS), which is secreted by >98% of all known Escherichia coli (E. coli) strains. The immobilization of fluorogenic and chromogenic substrates in specified...

This work reports on a new approach to rapidly and selectively detect and discriminate enzymes of pathogenic from those of non-pathogenic bacteria using a patterned autonomously reporting hydrogel on a transparent support, in which the selectivity has been encoded by pattern shape to enable facile detection by a color change at one single wavelengt...

Inside Front Cover: The genetically modified reporter bacteria Escherichia coli pTetR-LasR-pLuxR-GFP were entrapped into multi-component hydrogel microarrays to fabricate point-of-care biosensors for monitoring bacterial infections caused by Pseudomonas aeruginosa. The hybrid hydrogel was formed by combining the supramolecular self-assembly of a lo...

A generally applicable strategy to obtain mechanically robust hydrogels for the incorporation and containment of functional reporter bacteria for the microarray and microparticle-based detection and signaling of N-acyl homoserine lactone autoinducers (3OC12HSL) at relevant concentrations is reported. For reinforcing hydrogels of 1,4-bi(phenylalanin...

Quorum sensing, in which bacteria communities use signaling molecules for inter- and intracellular communication, has been intensively studied in recent decades. In order to fabricate highly sensitive easy-to-handle point of care biosensors that detect quorum sensing molecules, we have developed, as is reported here, reporter bacteria entrapped alg...

The combination of supramolecular hydrogels formed by low molecular weight gelator self-assembly via non-covalent interactions within a scaffold derived from polyethylene glycol (PEG) affords an interesting approach to immobilize fully functional, isolated reporter bacteria in novel microwell arrays. The PEG-based scaffold serves as a stabilizing e...

We report on the development of an autonomously reporting indicator hydrogel for the rapid and selective detection of enzymes secreted by the food-borne biosafety level 3 pathogen enterohemorrhagic Escherichia coli (E. coli) O157:H7 (EHEC) and the differentiation of this pathogen from the non-virulent E. coli strain K12. To introduce the sensing fu...

Under a variety of circumstances, melanin occurs in the dermal compartment of the skin, being mostly observed in cells that have been termed melanophages, some of which have been identified as dermal dendritic cells. We analysed changes in the expression and secretion pattern of cytokines by dendritic cells after the uptake of melanin from various...

Endometrial carcinoma (EC) is the most common gynecological malignancy in the western world. A widely accepted dualistic model, which has been established on a morphological basis, differentiates EC into two broad categories: Type I oestrogen-dependent adenocarcinoma with an endometrioid morphology and Type II non-oestrogen-dependent EC with a sero...