Publications by authors named "Mika Linden"

Roseburia intestinalis, enriched in the gut, is closely associated with obesity, intestinal inflammation, and other diseases. A novel detection method for R. intestinalis to replace the commonly used 16S rRNA sequencing technique is aim to developed, thus enabling real-time and low-cost monitoring of gut microbiota.

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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 investigates the conjugation of EPI-X4 derivatives with long-chain fatty acids, enhancing serum albumin interaction and receptor affinity.

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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 size, mesopore geometry, and surface polarity all had an influence on the peptide adsorption in terms of both affinity and maximum loading at a given pH.

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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 inflammatory bowel disease (IBD). In this study, we synthesized rod-shaped mesoporous silica nanoparticles (MSNs) functionalized with polyethylene glycol (PEG) or hyaluronic acid (HA) and investigated their bio-distribution upon oral administration in vivo.

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Silica nanoparticles (SNP) have gained tremendous attention in the recent decades. They have been used in many different biomedical fields including diagnosis, biosensing and drug delivery. Medical uses of SNP for anti-cancer, anti-microbial and theranostic applications are especially prominent due to their exceptional performance to deliver many different small molecules and recently biologics (mRNA, siRNA, antigens, antibodies, proteins, and peptides) at targeted sites.

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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 are recognition of the nanoparticles as foreign objects, which triggers nanoparticle uptake by defence organs rich in macrophages, liver and spleen, on the time-scale of accumulation and uptake in/by the tumour. However, the development of nanomedicine towards efficient nanoparticle-based delivery to solid tumours is hampered by the lack of simple, reproducible, cheap, and predictive means for early identification of promising nanoparticle formulations.

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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 transient opening of the gut epithelium. In this study, we have developed small-sized (∼60 nm) virus-like silica nanoparticles (VSNP) as a reversible and next generation non-toxic permeation enhancer for oral delivery of biologics.

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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 through surface functionalization with poly(ethylene glycol) (PEG) (PEGylation), has repeatedly been shown to be detrimental for the drug loading levels that can be achieved.

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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 temperature-resolved small-angle X-ray scattering, transmission electron microscopy, and H NMR spectroscopy to elucidate the detailed kinetics and mechanism of structure formation.

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Li-rich layered oxides (LRLO) with specific energies beyond 900 Wh kg 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 Li Mn Ni O was investigated.

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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 prevailing during in vitro or in vivo administration of the particles. Furthermore, typically the dissolution studies are limited with respect to the range of MSN concentrations applied.

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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.

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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@TiO dipstick) for chemical-free sample preparation and mercury preconcentration. For this purpose, AuNPs are immobilized onto a silicon wafer and further covered with a thin photoactive titanium dioxide layer.

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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).

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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 conditions and thus often stays overlooked. In this work, we utilize an in-house established bioassay for targetability validation of mesoporous silica nanoparticles (MSNs), functionalized with high-affinity peptide ligands to somatostatin receptors via protective group chemistry, ensuring the correct orientation of the peptide's pharmacophore.

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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 peptides and proteins) is one of the major challenges faced by the biopharmaceutical industry. This is even more important since a large number of biologic drugs have been available in the past decade which typically require intravenous administration.

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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-chorioallantoic membrane (HET-CAM) model is of special interest, as it is not considered an animal until day 17.

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A study of a protein corona on mesoporous silica nanoparticles (MSNs) at and 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 collected and analyzed by DLS, zeta-potential, and TGA, and the corona proteins were analyzed with SDS-PAGE.

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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 3D surfaces or creating patterned surfaces is a challenge using coating techniques like spin- and dip-coating. In this study, mesoporous films consisting of SBA-15 particles grown onto silicon wafers using wet processing were evaluated as a scaffold for drug delivery.

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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 regard to their electrochemical performance.

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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 target for TB therapy.

Methods And Findings: We have previously identified a peptide, called NZX, capable of inhibiting both clinical and multi-drug resistant strains of M.

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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 novel thin film sampling stick for passive sampling based on gold nanoparticles. The nanoparticles supported on a silicon wafer and further covered with a thin layer of mesoporous silica.

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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.

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

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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 enables the synthesis of silica nanoparticles without any catalyst or elevated temperatures under static conditions. This is in contrast to syntheses for sub-20-nm silica nanoparticles described until now which can normally not be conducted at neutral pH and/or room temperature without stirring.

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