Mika Lindén

Ulm University | UULM · Institute of Inorganic Chemistry II (Synthesis and Characterization of Inorganic Materials)

Transfection of mammalian and human cell lines in medical research both are key technologies in molecular biology and genetic engineering. A vast variety of techniques to facilitate transfection exists including different chemical and nanoparticle-based agents as mediators of nucleic acid uptake, with nanoparticles composed of the lipids DOSPA/DOPE...

Dysregulation of the CXCL12/CXCR4 axis is implicated in autoimmune, inflammatory, and oncogenic diseases, positioning CXCR4 as a pivotal therapeutic target. We evaluated optimized variants of the specific endogenous CXCR4 antagonist, EPI-X4, addressing existing challenges in stability and potency. Our structure-activity relationship study investiga...

The adsorption of cationic peptide JM21 onto different mesoporous silica nanoparticles (MSNs) from an aqueous solution was studied as a function of pH. In agreement with the literature, the highest loading degrees could be achieved at pH close to the isoelectric point of the peptide where the peptide–peptide repulsion is minimum. However, mesopore...

Besides the many advantages of oral drug administration, challenges like premature drug degradation and limited bioavailability in the gastro-intestinal tract (GIT) remain. A prolonged residence time in the GIT is beneficial for enhancing the therapeutic outcome when treating diseases associated with an increased intestinal clearance rate, like inf...

An efficient nanoparticulate drug carrier intended for chemotherapy based on intravenous administration must exhibit a long enough blood circulation time, a good penetrability into the tumour volume, as well as an efficient uptake by cancer cells. Limiting factors for the therapeutic outcome in vivo are recognition of the nanoparticles as foreign o...

Background Chlorin e6 trisodium salt (Ce6) is a newly developed hydrophilic photosensitizer designed to mediate anticancer photodynamic therapy (PDT). The response of different cancer types and strategies to boost anticancer efficiency of Ce6-PDT are poorly studied. Objectives This study aimed to investigate the response of different cancer types...

Nanoparticle based permeation enhancers have the potential to improve the oral delivery of biologics. Recently, solid silica nanoparticles were discovered to improve the intestinal permeability of peptides and proteins via transient opening of the gut epithelium. In this study, we have developed small-sized (∼60 nm) virus-like silica nanoparticles...

Mesoporous silica nanoparticles (MSNs) have emerged as a very promising drug delivery platform. However, multi-step synthesis and surface functionalization protocols rise the hurdle for translation of this promising drug delivery platform to the clinic. Furthermore, surface functionalization aiming at enhancing the blood circulation time, typically...

Light-driven production of hydrogen peroxide via selective dioxygen reduction is an attractive “green” alternative to the conventionally used anthraquinone process. One of the most promising classes of photocatalytic materials for...

Structural evidence of a Li ⁺ induced phase segregation on particle level in Co-free layered Li–Mn–Ni-oxide cathode materials for Li-ion batteries is presented, illustrating the importance of correlative SEM–Raman microscopy in battery research.

The electrochemical activation of Li 2 MnO 3 domains in Li- and Mn-rich layered oxides (LRLO) is highly important, and can be tuned by surface modification of the active materials to improve their cycling performance. In this study, citric acid was employed as a combined organic acid, reducing agent, and carbon precursor in order to remove surface...

Doping of Ni-rich LNMC cathode materials with tungsten via a solid-state route has been shown to stabilize the materials against structural degradation at high voltages during electrochemical cycling. Here we use a wet-chemical doping method to homogeneously introduce 0.5 mol% tungsten into dense NMC811 (Li[(Ni0.8Mn0.1Co0.1)]O2), followed by a deta...

Detrimental side-reactions of Ni-rich cathode active materials (CAMs) with the electrolyte have historically impeded the extension of the utilized voltage window to higher upper cut-off voltages. Doping and coating approaches are studied widely to further improve these materials and to reduce the intensity of bulk and surface degradation but suffer...

Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer characterized by late diagnosis, lack of early symptoms and extensive metastasis. One of the foremost reasons for such startling statistics is the presence of a subpopulation of highly plastic stem-like cells within the tumor called cancer stem cells (CSCs). We have previously identified a...

Light-driven production of hydrogen peroxide via selective dioxygen reduction is an attractive “green” alternative to the conventionally used anthraquinone process. One of the most promising classes of photocatalytic materials for this conversion that excels by high selectivity, chemical stability and low cost is represented by polymeric carbon nit...

Driven by the climate change the entire industry undergoes a structural change. Energy storage solutions, like lithium ion batteries (LIBs), become more and more important. ¹ The development of new materials with higher specific energy, lower costs and reduced amount of critical raw materials, such as Co and Ni, is one of the most important key poi...

Li‐rich layered oxides (LRLO) with specific energies beyond 900 Wh kg⁻¹ are one promising class of high‐energy cathode materials. Their high Mn‐content allows reducing both costs and the environmental footprint. In this work, Co‐free Li1.2Mn0.6Ni0.2O2 was investigated. A simple water and acid treatment step followed by a thermal treatment was appli...

Ni-rich, cathode active materials such as Li[Ni0.8Mn0.1Co0.1]O2 (NMC811) suffer from capacity fade, especially at higher upper cut-off voltages. There is an increasing interest on dopants such as Mo or Ta as a promising dopants for high-Ni materials. In this study four cathode active materials with Li[(Ni0.78Mn0.11Co0.11)1-xMx]O2 (NMC811, x=0, 0.00...

In a previous contribution we described the formation of silica nanostructures in dye-stabilized nanoemulsions from tetraethyl orthosilicate droplets in water. Depending on the type of dye, either capsules (crystal violet, CV) or nanoparticles (congo red, CR) are formed. The thorough study of the sol-gel process uses a combination of time- and/or t...

Light-driven production of hydrogen peroxide via selective dioxygen reduction is an attractive “green” alternative to the conventionally used anthraquinone process. One of the most promising classes of photocatalytic materials for this conversion that excels by high selectivity, chemical stability and low cost is represented by polymeric carbon nit...

Superparamagnetic iron oxide nanoparticles, SPIONs, especially in the form of nanoscopic aggregates thereof, find broad applications as magnetic resonance imaging contrast agents, as biological tools for straightforward separation of biomolecules and cells, as magnetically tunable colorimetric sensors exhibiting structural colors, etc. Furthermore,...

Sodium-ion batteries promise efficient, affordable and sustainable electrical energy storage that avoids critical raw materials such as lithium, cobalt and copper. In this work, a manganese-based, cobalt-free, layered NaxMn3/4Ni1/4O2 cathode active material for sodium-ion batteries is developed. A synthesis phase diagram was developed by varying th...

Nanoparticles are used as drug carriers to increase the selectivity and effectiveness of therapy, as well as for combined therapy that utilizes different effects. Iron oxide nanoparticles are promising in this aspect. Due to magnetic properties, they can be used as a contrast agent for magnetic resonance imaging. Also, iron oxide nanoparticles coul...

We present FIB/SEM tomography combined with an optimized embedding procedure and osmium tetroxide staining to trace and visualize the initial self-conditioning step as well as degradation processes of [5,15-bis(ethynyl)-10,20-diphenylporphinato]copper(II) (CuDEPP) composite electrodes for the first time. Staining with osmium tetroxide allowed visua...

Self-assembled peptide fibrils are abundant in in vivo systems and have been associated both with normal physiological functions and with different diseases. Herein, a proof-of-concept study is presented, where aggregates of synthetic, fibril-forming peptides are studied as carriers for mesoporous silica nanoparticles (MSNs), giving a hydrogel@MSN...

Mesoporous silica nanoparticles (MSN) are promising drug vectors due to their high drug loading capacities, degradability under biologically relevant conditions. The dissolution of MSN has been the focus of several recent studies, most of which have, however, been carried out in the absence of proteins, and do therefore not reflect the conditions p...

In article number 2100453 by Steffen Stenger, Mika Lindén, and co‐workers, the activity of the antimicrobial peptide NapFab against intracellular Mycobacterium tuberculosis (Mtb) is significantly increased by loading onto dendritic mesoporous silica nanoparticles (DMSN). This enhanced activity is based on a 30‐fold increased, DMSN‐mediated peptide...

Tuberculosis remains a serious global health problem causing 1.3 million deaths annually. The causative pathogen Mycobacterium tuberculosis (Mtb) has developed several mechanisms to evade the immune system and resistances to many conventional antibiotics, so that alternative treatment strategies are urgently needed. By isolation from bronchoalveola...

Due to its low-cost and environmental friendliness, birnessite-type manganese oxide has attracted wide interest for use as a cathode material in electrochemical energy storage applications. The mechanisms of energy storage and release have been studied in some detail during the last decade, but despite some agreement, some aspects of the storage an...

The early stages of tricalcium silicate hydration has been studied by in situ ATR-FTIR spectroscopy. A method for data reduction based on background correction and subtraction of spectra of pure components is presented, which makes it possible to describe the kinetic evolution of the calcium silicate hydrate phase upon hydration with great detail....

Mercury detection in humic matter-containing natural waters is often associated with environmental harmful substances for sample preparation. Herein we report an approach based on photoactive titanium dioxide films with embedded gold nanoparticles (AuNP@TiO2 dipstick) for chemical-free sample preparation and mercury preconcentration. For this purpo...

Many transition-metal dichalcogenides show competing metallic, superconducting, charge density waves (CDWs), or Mott-insulating phases. Understanding the interplay between these phases is of fundamental interest. One approach to understand this relationship is to suppress one or more of the competing phases through systematic introduction of disord...

Birnessite-type manganese oxides, consisting of stacked MnOx sheets, separated by charge-balancing metal ions and structural water are potential candidates for electrochemical applications. Due to their structural complexity, Raman spectroscopy is...

The typical method for minimizing serum protein adsorption in biological settings and prolonging blood circulation time of nanoparticles, is to anchor hydrophilic polymers (e.g., poly(ethylene glycol), PEG) on the particle surface, which is most often done by covalent attachment (PEGylation). Herein, different PEGylation methods were realised and c...

When a material comes in contact with serum or plasma, proteins will immediately adsorb to its surface. The extent of serum protein adsorption as well as the composition of the protein corona is thought to be decisive for the biological fate. The understanding of the mechanism underlying the concurrent adsorption of multiple proteins and the exact...

Demonstration of receptor-mediated targeting of nanoparticles to specific organs and/or cell types is an integral aim in many bionanomedicine development projects. However, engagement of targeted receptors with ligands on nanocarriers, which is the cornerstone of the active targeting concept, is challenging to study under biologically relevant cond...

It has been shown that the optimized VIR-576 derivative of the natural HIV-1 entry inhibitor targeting the viral gp41 fusion peptide is safe and effective in infected individuals. However, high doses of this peptide were required, and stability, as well as delivery, must be improved for clinical application. Here, we examined the loading and releas...

Oral ingestion remains as the most convenient route of administration for the application of pharmaceuticals since it is non-invasive and does not require trained personnel to administer the drugs. Despite significant progress in novel oral drug delivery platforms over the past few decades, the oral delivery of macromolecules (particularly for pept...

The validation of novel target-specific radioligands requires animal experiments mostly using mice with xenografts. A pre-selection based on a simpler in vivo model would allow to reduce the number of animal experiments, in accordance with the 3Rs principles (reduction, replacement, refinement). In this respect, the chick embryo or hen’s egg test–c...

The Hen's Egg Test Chorioallantoic Membrane (HET-CAM) of fertilized chick eggs represents a unique model for biomedical research. With its steadily increasing use, non-invasive in ovo imaging for longitudinal direct quantification of the biodistribution of compounds or monitoring of surrogate markers has been introduced. The full range of imaging m...

A study of a protein corona on mesoporous silica nanoparticles (MSNs) at in vitro and in vivo relevant serum concentrations is presented. Three MSNs different in terms of mesoscopic pore arrangement, surface chemistry, and surface roughness were studied. After incubation in either 10% or 100% serum, the hard protein corona–particle complexes were c...

Spatially and temporally controlled drug delivery is important for implant and tissue engineeringapplications, as the efficacy and bioavailability of the drug can be enhanced, and can also allow fordrugging stem cells at different stages of development. Long-term drug delivery over weeks to monthsis however difficult to achieve, and coating of 3D s...

Silicon oxycarbides (SiOC) are an interesting alternative to state-of-the-art lithium battery anode materials, such as graphite, due to potentially higher capacities and rate capabilities. Recently, it was also shown that this class of materials shows great prospects towards sodium ion batteries. Yet, bulk SiOCs are still severely restricted with r...

Spatially and temporally controlled drug delivery is important for implant and tissue engineering applications, as the efficacy and bioavailability of the drug can be enhanced, and can also allow for drugging stem cells at different stages of development. Long-term drug delivery over weeks to months is however difficult to achieve, and coating of 3...

Spatially and temporally controlled drug delivery is important for implant and tissue engineering applications, as the efficacy and bioavailability of the drug can be enhanced, and can also allow for drugging stem cells at different stages of development. Long-term drug delivery over weeks to months is however difficult to achieve, and coating of 3...

Determination of mercury traces in the hydrosphere is an important and still challenging analytical task. Here we report on a novel solid phase extraction (SPE) method for total dissolved mercury (Hg) determination in natural waters using newly developed nanogold-coated dipsticks. Straightforward preparation of the dipsticks comprises golf film dep...

Background Intracellular delivery of antimicrobial agents by nanoparticles, such as mesoporous silica particles (MSPs), offers an interesting strategy to treat intracellular infections. In tuberculosis (TB), Mycobacterium tuberculosis avoids components of the immune system by residing primarily inside alveolar macrophages, which are the desired tar...

Resazurin microtiter assay was used for MIC comparison between free peptide and peptide loaded in particles. Representative image identical MIC at 3.2 uM for both formulations. (TIF)

Trace-level detection of mercury in waters is connected with several complications including complex multistep analysis routines, applying additional, harmful reagents increasing the risk of contamination, and the need for expensive analysis equipment. Here, we present a straightforward reagent-free approach for mercury trace determination using a...

Mesoporous silica nanoparticles (MSNs) are currently attracting a high interest for use as drug carriers in vivo. To date only data on the biodistribution in small animals are available. As any nanoparticle system, the MSNs typically accumulate in the RES organs lung, liver, and spleen upon intravenous (i.v.) administration. However, the literature...

Objectives A common limitation of all ¹H contrast agents is that they only allow indirect visualization through modification of the intrinsic properties of the tissue, making quantification of this effect challenging. ¹⁹F compounds, on the contrary, are measured directly, without any background signal. There is a linear relationship between the amo...

Dye stabilized nanoemulsions offer the unique possibility of creating both silica capsules and sub-20 nm particles with precise control of particle size and narrow dispersity from the same system by the choice of the proper dye. The large o/w interface enhances the kinetics of particle formation significantly over macroscopic interfaces which enabl...

Colorimetric or luminogenic cytotoxicity assays are typically applied for in vitro cytotoxicity evaluations due to their easy handling and low cost. However, the results may be strongly assay-dependent. Furthermore, when applied to nanoparticle toxicity screening, nanoparticle-specific interferences can occur. Therefore, it is important to evaluate...

An innovative approach for molecularly imprinting proteins, i. e., inhibitor‐assisted imprinting was used for addressing the major challenge of protein purification from biotechnologically relevant media. Pepstatin‐assisted pepsin surface‐imprinted microbeads were synthesized as a selective sorbent for solid phase extraction (SPE). The amino‐functi...

Highly microporous submicromentric carbon spheres were synthesized via etching of a sol-gel derived silicon oxycarbide (SiOC) material with aqueous hydrofluoric acid solution. The resulting material shows a large total pore volume of 0.63 cm3g-1 and thus acts as an ideal host for elemental sulfur. Via melt impregnation a carbon-sulfur composite (50...