Dagmar Fischer

Friedrich-Alexander-University Erlangen-Nürnberg · Chemistry and Pharmacy

In our prior research, polymer nanoparticles containing tobramycin displayed robust antibacterial efficacy against biofilm-embedded Pseudomonas aeruginosa and Burkholderia cenocepacia cells, critical pathogens in cystic fibrosis. In the current study, we investigated the deposition of a nanoparticulate carrier composed of poly(D,Llactic-co-glycolic...

Bacterial cellulose (BC) is a versatile and sustainable biomaterial with applications across various industries, including fashion and medicine. This study presents a bibliometric and thematic analysis of the research landscape surrounding BC production with the use of alternative substrates. The bibliometric review analyzed 198 papers selected via...

Ultra-high molecular weight polyethylene (PE-UHMW) fibers and bacterial nanocellulose (BNC) fibers both display exceptional mechanical properties alongside the outstanding tribological properties of PE-UHMW while showing an unrestricted biocompatibility. For combining the intrinsic advantages of both materials, the present work demonstrates an appr...

Histidine and arginine are two amino acids that exhibit beneficial properties for gene delivery. In particular, the imidazole group of histidine facilitates endosomal release, while the guanidinium group of arginine promotes cellular entry. Consequently , a dual-charged copolymer library based on these amino acids was synthesized via reversible add...

Bacterial cellulose is a versatile material with applications in many industries. However, the widespread uptake of bacterial cellulose faces challenges including high production costs and lack of scalability. One approach to address these obstacles is the use of alternative substrates and media, compared to the Hestrin-Schramm (HS) media. By evalu...

Focused ultrasound (FUS) can be used as a drug delivery application for localized chemotherapy to treat cancer. The effect of ultrasound-induced inertial cavitation is promising to trigger drug release from nanocarriers. To investigate this effect, usually, a passive cavitation detection setup is employed. However, applying such a setup is challeng...

The formulation of drugs in poly(lactic-co-glycolic acid) (PLGA) nanoparticles can be accomplished by various methods, with nanoprecipitation and nanoemulsion being among the most commonly used manufacturing techniques to provide access to high-quality nanomaterials with reproducible quality. Current trends turned to sustainability and green concep...

3D printing offers new opportunities to customize oral dosage forms of pharmaceuticals for different patient populations, improving patient safety, care, and compliance. Although several notable 3D print technologies have been developed, such as inkjet printing, powder-based printing, selective laser sintering (SLS) printing, and fused deposition m...

Controlled drug delivery (CDD), the controlled release and delivery of therapeutic drugs inside the human body, is a promising approach to increase the efficacy of drug administration and reduce harmful side effects to the body. CDD has been a major research focus in the field of molecular communications (MC) with the goal to aid the design and opt...

The "biological identity" of nanoparticles (NPs) is governed by a shell consisting of various biomolecules that is formed upon exposure to biological media, the so-called biomolecule corona. Consequently, supplementation of cell culture media with e.g. different sera is likely to affect interactions between cells and NPs ex-vivo, especially endocyt...

In this work, the manufacture of amorphous solid dispersions of poorly water-soluble carbamazepine using a laboratory spray drying setup with a three-fluid nozzle and two separate liquid feed solutions of (a) the active and (b) the polymeric excipient (copovidone or basic butylated methacrylate copolymer) was investigated and compared to a traditio...

Bacterial nanocellulose has been widely investigated in drug delivery, but the incorporation of lipophilic drugs and controlling release kinetics still remain a challenge. The inclusion of polymer particles to encapsulate drugs could address both problems but is reported sparely. In the present study, a formulation approach based on in situ precipi...

Simple Summary The chorioallantoic membrane (CAM) model is an alternative in vivo test system for the study of hallmarks of cancer such as angiogenesis, tumor growth, immune escape, metastasis, and drug resistance. It is suitable for tumor cell lines and patient-derived xenografts (PDX), allowing for studying treatment protocols for cancer patients...

The mechanism of RNA interference (RNAi) could represent a breakthrough in the therapy of all diseases that arise from a gene defect or require the inhibition of a specific gene expression. In particular, small interfering RNA (siRNA) offers an attractive opportunity to achieve a new milestone in the therapy of human diseases. The limitations of si...

Systemic administration of histone deacetylase inhibitors (HDACi), like valproic acid (VPA), is often associated with rapid drug metabolization and untargeted tissue distribution. This requires high-dose application that can lead to unintended side effects. Hence, drug carrier systems such as nanoparticles (NPs) are developed to circumvent these di...

Bacterial nanocellulose has been widely investigated for wound healing applications, mainly due to its moisturizing capabilities and biocompatibility. Even though the topical therapy of nail diseases could benefit from these properties, this application has not yet been investigated. Therefore, actively hydrating nail patches based on bacterial nan...

A passive cavitation detection setup is used to assess and verify the capability of frequency- and amplitudemodulated ultrasound burst signals on the generation of inertial cavitation. The measurements were conducted with a flowthrough tissue-mimicking phantom with a canal of dc = 1mm in diameter simulating a fine blood vessel. By means of a flow v...

A Raman-based label-free analytical method was developed to detect the antibiotic ciprofloxacin (CIP) in various pharmaceutical formulations in the presence of different matrices (e.g., ear drops, eye drops and infusion solutions). The Raman spectral analysis is performed for semiquantification in the case of a low background Raman signal, i.e., th...

The application of Raman spectroscopic methods in life science applications has entered a new era due to advances in instrumentation, miniaturization and, most importantly, increased interdisciplinary dialogue between spectroscopists and end users such as clinicians or pharmacists. Advances in laser sampling technologies, optical instruments and da...

Background Insufficient solubility and stability of bioactive small molecules as well as poor biocompatibility may cause low bioavailability and are common obstacles in drug development. One example of such problematic molecules is 6-bromoindirubin-3'-glycerol-oxime ether (6BIGOE), a hydrophobic indirubin derivative. 6BIGOE potently modulates the r...

Bacterial nanocellulose (BNC) is a highly interesting biomaterial due to some outstanding properties especially when used in medical therapeutics and diagnostics. BNC is absolutely bioinert and is characterised by intrinsic properties such as high tensile stiffness and elasticity, high porosity, exceptional water uptake and swelling capacity. Furth...

Human hepatocellular carcinoma (HCC) is among the most lethal and common cancers in the human population, and new molecular targets for therapeutic intervention are urgently needed. Deleted in liver cancer 1 (DLC1) was originally identified as a tumor suppressor gene in human HCC. DLC1 is a Rho-GTPase-activating protein (RhoGAP) which accelerates t...

A promising approach to drug delivery applications for chemotherapeutics is the use of drug carriers to reduce the total amount of cytostatics, minimizing side effects. In addition, the carriers, loaded with the drug, can be guided to the tumorous tissue via the vascular system, which enables a local drug release (LDR). In our case, LDR is activate...

Magnetic nanoparticles (MNPs) are interesting for various applications in medicine. If administered to a biological system like the human body, a so-called biomolecule corona is formed on the surface of the particles, which highly determines the biological fate of the particles. To elucidate whether a preconditioning of the MNPs by incubation with...

Diflapolin is a dual FLAP/sEH inhibitor with potent anti-inflammatory efficiency in cellular assays and experimental in vivo studies. Despite these outstanding characteristics, its high lipophilicity and plasma protein binding hamper the bioactivity in blood. To overcome these limitations, diflapolin was encapsulated in poly(lactic-co-glycolic acid...

Background: Poly lactic-co-glycolic acid (PLGA) nanoparticles can be prepared by emulsion-solvent-evaporation from o/w and w 1 /o/w 2 emulsions. Aims: To elaborate similarities and differences regarding mechanical, morphological and physicochemical properties, as well as endocytosis and dose-dependent immune responses by primary human leukocytes be...

Inflammation is a hallmark of tissue remodeling during wound healing. The inflammatory response to wounds is tightly controlled and well-coordinated; dysregulation compromises wound healing and causes persistent inflammation. Topical application of natural anti-inflammatory products may improve wound healing, in particular under chronic pathologica...

This study describes the first example for shielding of a high performing terpolymer that consists of N-(2-hydroxypropyl)methacrylamide (HPMA), N-(3-guanidinopropyl)methacrylamide (GPMA), and N-(2-indolethyl)methacrylamide monomers (IEMA) by block copolymerization of a polyethylene glycol derivative – poly(nona(ethylene glycol)methyl ether methacry...

Aim: In this study, the influence of a serum albumin (SA) and human plasma (HP) derived protein- and lipid molecule corona on the toxicity and biodegradability of different iron oxide nanoparticles (IONP) was investigated. Methods: IONP were synthesized and physicochemically characterized regarding size, charge, and colloidal stability. The adso...

Tripterygium wilfordii glycosides (TWG) is a traditional Chinese medicine with effectiveness against rheumatoid arthritis (RA), supported by numerous clinical trials. Lipid mediators (LM) are biomolecules produced from polyunsaturated fatty acids mainly by cyclooxygenases (COX) and lipoxygenases (LOX) in complex networks which regulate inflammation...

Inside Cover: In article number 2000580 by Dagmar Fischer, Kalina Peneva, and co‐workers, guanidinium, containing methacrylamide terpolymers with three different side chains mimicking hydrophobic amino acid residues, are designed to evaluate to what extent does the identity of these hydrophobic groups influence the binding, protection, and transfec...

The pentacyclic triterpenoid quinone methide celastrol (CS) from Tripterygium wilfordii Hook. F. effectively ameliorates inflammation with potential as therapeutics for inflammatory diseases. However, the molecular mechanisms underlying the anti-inflammatory and inflammation-resolving features of CS are incompletely understood. Here we demonstrate...

Polymerization-induced self-assembly (PISA) is an emerging methodology for the in situ preparation of complex polymeric nanostructures in aqueous solution. However, the scope of monomers allowing morphology transitions remains limited, which is related to the low solubility of many monomers in water. Morphology transitions have therefore been restr...

In the present study, the anti-inflammatory lipophilic drug atorvastatin was encapsulated in poly(D,L-lactide-co-glycolide) (PLGA) using a sustainable method in comparison to the standard emulsion-diffusion-evaporation technique. For the sustainable method the organic solvent ethyl acetate was fully replaced by 400 g/mol poly(ethylene glycol) (PEG...

Fungal natural compounds are industrially produced, with application in antibiotic treatment, cancer medications, and crop plant protection. Traditionally, higher fungi have been intensively investigated concerning their metabolic potential, but reidentification of already known compounds is frequently observed. Hence, alternative strategies to acq...

Natural products suited for prophylaxis and therapy of inflammatory diseases have gained increasing importance. These compounds could be beneficially integrated into bacterial cellulose (BC), which is a natural hydropolymer applicable as a wound dressing and drug delivery system alike. This study presents experimental outcomes for a natural anti-in...

Magnetic nanoparticles (MNPs) are interesting for various applications in medicine. If administered to a biological system like the human body, a so-called biomolecule corona is formed on the surface of the particles, which highly determines the biological fate of the particles. To elucidate whether a preconditioning of the MNPs by incubation with...

Toxic and environmental harmful organic solvents are widely applied to prepare poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles (NP) in standard preparation methods. Alternative non-toxic solvents suffer from disadvantages like high viscosity and plasticizing effects. To overcome these hurdles, Cyrene™ as a new sustainable, non-toxic and lo...

This report highlights the importance of hydrophobic groups mimicking the side chains of aromatic amino acids, which are tryptophan, phenylalanine, and tyrosine, in guanidinium bearing poly(methacrylamide)s for the design of non‐viral gene delivery agents. Guanidinium containing methacrylamide terpolymers are prepared by aqueous reversible addition...

Three-dimensional (3D) screen printing was used to fabricate oral dosage forms of different geometry and size. The paste required as starting material for the 3D screen printing process was designed for delayed release and contained the model drug paracetamol (acetaminophen). A prototype screen printing unit was used to fabricate different tablets...

Biotech nanocellulose (bacterial nanocellulose, BNC) is a high potential natural polymer. Moreover, it is the only cellulose type that can be produced biotechnologically using microorganisms resulting in hydrogels with high purity, high mechanical strength and an interconnecting micropore system. Recently, the subject of intensive research is to in...

Die Sättigung der traditionellen Märkte in USA, Europa und Japan sowie der drohende Ablauf des Patentschutzes für viele Blockbuster zwingen die Originatoren in neue Märkte zu diversifizieren. Gleichzeitig wächst der Generika-Markt weiter. Mit geschätzten 52 % in den globalen Ausgaben für pharmazeutische Produkte zwischen 2014 und 2018 ist dem Gener...

Der Wunsch, ja das Bedürfnis, Krankheiten zu lindern oder zu heilen, kann ohne Frage als eine der wichtigsten Triebfedern zur Entwicklung von Arzneimitteln im weitesten Sinne angesehen werden. Arzneimittel sind rückdatierbar bis auf 2100 v. Chr., und alle großen Kulturen trugen zur Weiterentwicklung der Medizin und Heilkunst bei.

Vergleicht man die Statistiken einschlägiger Wirtschaftsverbände, Analysen führender Unternehmensberatungen sowie die Schlagzeilen der Wirtschaftszeitungen zur Situation der pharmazeutischen Industrie, so sind die Meinungen über die Zukunft dieses Industriezweiges immer wieder geteilt. Während die Einen die neu eingeführten Medikamente der forschen...

Während Arzneimittel seit dem späten Mittelalter in Form von Rezepturarzneien traditionell in Apotheken hergestellt wurden, änderte sich dies gegen Ende des 19. Jahrhunderts zusehends, als einige Apotheker dazu übergingen, ihre Produkte abgabefertig unter eigenem Namen in den Handel zu bringen. So wurde der Grundstein für die industrielle Arzneimit...

Pharmaunternehmen sehen sich heute einer Vielzahl komplexer Herausforderungen gegenüber; der Gesundheitsmarkt befindet sich im Umbruch. Analysiert man das derzeitige Bild der Branche, so ergeben sich eine Reihe wegweisender Trends, die gleichsam miteinander verflochten sind und in ihrem Zusammenspiel eine chancenreiche Ausgangssituation für das Pha...

The development of bio-based nanoparticles (NPs) as drug containers is of increasing interest to circumvent several obstacles in drug therapy such as rapid drug metabolization, short serum half-life, and unspecific side effects. The histone deacetylase inhibitor valproic acid (VPA) is known for its anti-inflammatory as well as for its anti-cancer a...

Dextran‐formamidine esters (dextran‐N‐[(dimethylamino)methylene]‐β‐alanine ester) with different degrees of substitution (0.45–0.92) are synthesized in an one‐pot reaction. Dextran (Mw 60 000 g mol−1) is allowed to react with unprotected beta‐alanine and iminium chloride and investigated regarding the potential as gene delivery system for the trans...

Fungi are traditionally considered as reservoir of biologically active natural products. However, an active secondary metabolism has long not been attributed to early diverging fungi such as Mortierella spec . Here, we report on the biosynthesis of two series of cyclic pentapeptides, the malpicyclins and malpibaldins, as products of Mortierella alp...

The combination of the anti-inflammatory lipophilic Boswellia serrata extract with the natural hydropolymer bacterial nanocellulose (BNC) for the treatment of skin diseases is counteracted by their different hydro/lipophilicity. To overcome the hydrophilicity of the BNC, the water in its network was exchanged by single and double nanoemulsions. Inc...

Indirubin is a natural bis-indole alkaloid contained as active ingredient in the traditional Chinese remedy Danggui Longhui Wan. Indirubin and its 3́-oxime derivatives exhibit anti-cancer and anti-inflammatory properties and they inhibit glycogen synthase kinase (GSK)-3 in cell-free assays where 6-bromoindirubin-3́-oxime (6BIO) is among the most po...

A shell-less hen’s egg based infection test with Pseudomonas aeruginosa was established to investigate the antimicrobial efficacy of drugs and drug formulations close to the in vivo situation. The test system using preincubated fertilized chicken eggs transferred in petri dishes was optimized with respect to the controlled local application of liqu...

In times of drastically increasing numbers of scientific reports dealing with the drawbacks of poly(ethylene glycol) (PEG), the search of PEG alternatives has never been more urgent. This study describes a one–to–one comparison of poly(2-ethyl-2-oxazoline)-b-poly(lactic-co-glycolic acid) (PEtOx-b-PLGA) to commercial PEG-b-PLGA from the bottom up in...

The histone deacetylase inhibitors (HDACi) are potent drugs in the treatment of inflammatory diseases and defined cancer types. However, major drawbacks of HDACi, such as valproic acid (VPA), are limited serum half‐life, side effects and the short circulation time. Thus, the immobilization of VPA in a polysaccharide matrix is used to circumvent the...

Front Cover: In article 1900668 by Dagmar Fischer, Kalina Peneva, and co‐workers, the incorporation of indole‐based monomers in guanidinium‐containing poly(methacrylamide)s leads to highly efficient transfection agents that can condense plasmid DNA even at a nitrogen‐to‐phosphate (N/P) ratio of 1 and show a 200‐fold increase in transfection compare...

A highly efficient transfection agent is reported that is based on terpolymer consisting of N-(2-hydroxypropyl)methacrylamide (HPMA), N-(3-guanidinopropyl) methacrylamide (GPMA), and N-(2-indolethyl)methacrylamide monomers (IEMA) by analogy to the amphipathic cell-penetrating peptides containing tryptophan and arginine residues. The incorporation o...

Bacterial cellulose (BC) has proven its high potential as active wound dressing and drug delivery system in many scientific studies, but the transferability of the methods to efficient manufacturing still needs to be demonstrated. This study presents a technically feasible, straightforward and efficient approach to modify BC according to specific m...

div> In this study, we report a highly efficient transfection agent based on terpolymer consisting of N-(2-hydroxypropyl)methacrylamide (HPMA), N-(3-guanidinopropyl) methacrylamide (GPMA), and N-(2-indolethyl)methacrylamide (IEMA) monomers by analogy to the amphipathic cell penetrating peptides containing tryptophan and arginine residues. The inco...

Dieses "Einsteiger"-Buch beschreibt die relevanten Schritte der Entwicklung von Arzneimitteln, über die Produktion, die Zulassung und die Vermarktung bis hin zur "Geschäftsentwicklung" sowie Patentierung werden die einzelnen Schritte kompakt erklärt. Sie finden detaillierte Antworten auf Fragen wie: Wie funktioniert die Arzneimittelentwicklung? We...

Herein, we report the first gradient guanidinium containing cationic copolymers and investigate their binding ability to plasmid DNA (pDNA). To understand the effect of different charge distribution and cationic charge sources (primary amines vs. guanidinium group) on (pDNA) binding affinity, we synthesized a library of well-defined statistical cat...

Aim: To simulate the stability and degradation of superparamagnetic iron oxide nanoparticles (MNP) in vitro as part of their life cycle using complex simulated biological fluids. Materials & methods: A set of 13 MNP with different polymeric or inorganic shell materials was synthesized and characterized regarding stability and degradation of core an...

Scope: Intake of flavonoids from the diet can be substantial, and epidemiological studies suggested that these compounds can decrease the incidence of cardiovascular diseases by involvement with increased platelet aggregation. Although parent flavonoids possess antiplatelet effects, the clinical importance is disputable due to their very low bioav...

Nowadays many drugs with improved therapeutic efficacy are discovered but cannot be utilized due to their low solubility and insufficient bioavailability. An example of such a drug molecule is a protein kinase C inhibitor that influences an enzyme which plays an important role in several signal transduction cascades. The aim of this study was to fo...

To form bio‐inspired non‐viral vectors for DNA delivery, the polysaccharide dextran is allowed to react with Boc‐amino protected amino acids glycine, β‐alanine, and L‐lysine activated with 1,1’‐carbonyldiimidazole and subsequent dextran ester deprotection. A library of such dextran esters is made available to investigate the relationship between po...

Introduction Healthcare-associated infections (HAIs) are a major health concern and have substantial effects on morbidity and mortality and increase healthcare costs. We investigated the effect of a hospital-wide program for the prevention of HAIs on additional length of stay (LOS). Methods We analyzed data from a prospective, single-center, quasi...

The synergy of the local delivery of nucleic acids using a hydrogel-based gene activated matrix (GAM) might support regenerative processes on a genetic level by concurrently providing a cell-friendly microenvironment. To investigate bacterial nanocellulose (BNC) as GAM, two plasmids (pSV-β-Gal and pGL3) were incorporated by reswelling and injection...