Vesa-Pekka Lehto

University of Eastern Finland | UEF · Department of Applied Physics

Drug carrier systems based on mesoporous inorganic nanoparticles generally face the problem of fast clearance from bloodstream thus failing in passive and active targeting to cancer tissue. To address this problem, a specific dual PEGylation (DPEG) method for mesoporous silicon (PSi) was developed and studied in vitro and in vivo. The DPEG coating...

Mesoporous silicon (PSi) nanoparticles have been widely studied in different biomedical imaging modalities due to its several beneficial material properties. However, they have not been found suitable for photoacoustic imaging due to their poor photothermal conversion performance. In the present study, biodegradable black mesoporous silicon (BPSi)...

Carbon nanotubes can be utilized in several ways to enhance the performance of silicon-based anodes. In the present work, thermally carbonized mesoporous silicon (TCPSi) microparticles and single-walled carbon nanotubes (CNTs) are conjugated to create a hybrid material that performs as the Li-ion battery anode better than the physical mixture of TC...

Cell membrane coated nanoparticles (NPs) have recently been recognized as attractive nanomedical tools because of their unique properties such as immune escape, long blood circulation time, specific molecular recognition and cell targeting. However, the integrity of the cell membrane coating on NPs, a key metrics related to the quality of these bio...

Visceral leishmaniasis is a vector-borne protozoan infection that is fatal if untreated. There is no vaccination against the disease, and the current chemotherapeutic agents are ineffective due to increased resistance and severe side effects. Buparvaquone is a potential drug against the leishmaniases, but it is highly hydrophobic resulting in poor...

Mesoporous silicon nanoparticles (PSi NPs) are promising platforms of nanomedicine because of their good compatibility, high payload capacities of anticancer drugs, and easy chemical modification. Here, PSi surfaces were functionalized with bisphosphonates (BP) for radiolabeling, loaded with doxorubicin (DOX) for chemotherapy, and the NPs were coat...

Many fluorophores, such as indocyanine green (ICG), have poor photostability and low photothermal efficiency hindering their wide application in photoacoustic (PA) tomography. In the present study, a supramolecular assembly approach was used to develop the hybrid nanoparticles (Hy NPs) of ICG and porous silicon (PSi) as a novel contrast agent for PA...

Landfill gas (LFG) is formed by microorganisms within a landfill; it can be utilized as a renewable fuel in power plants. Impurities such as hydrogen sulfide and siloxanes can cause significant damage to gas engines and turbines. The aim of this study was to determine the filtration efficiencies of biochar products made of birch and willow to remov...

The introduction of unintended oil spills into the marine ecosystem has a signifcant impact on aquatic life and raises impor tant environmental concerns. The present review summarizes the recent studies where nanocomposites are applied to treat oil spills. The review deals with the techniques used to fabricate nanocomposites and identify the charac...

The introduction of unintended oil spills into the marine ecosystem has a signifcant impact on aquatic life and raises important environmental concerns. The present review summarizes the recent studies where nanocomposites are applied to treat oil spills. The review deals with the techniques used to fabricate nanocomposites and identify the charact...

Barley husks are a byproduct of grain processing produced in large volumes globally. They contain a large amount of nanostructured silica (nSiO2) which can be converted via magnesiothermic reduction into carbon-rich nanostructured silicon carbide composite (nSiC/C). The nSiC/C can be further utilized as a precursor for the production of graphitic c...

Cell membrane (CM) coating technology is increasingly being applied in nanomedicine, but the entire coating procedure including adsorption, rupture , and fusion is not completely understood. Previously, we showed that the majority of biomimetic nanoparticles (NPs) were only partially coated, but the mechanism underlying this partial coating remains...

Photothermal therapy (PTT) in combination with other treatment modalities has shown great potential to activate immunotherapy against tumor metastasis. However, the nanoparticles (NPs) that generate PTT have served as the photothermal agent only. Moreover, researchers have widely utilized highly immunogenic tumor models to evaluate the immune respo...

Transmission electron microscopy (TEM) observations of negatively stained cell membrane (CM)‐coated polymeric nanoparticles (NPs) reveal a characteristic core‐shell structure. However, negative staining agents can create artifacts that complicate the determination of the actual NP structure. Herein, we demonstrate with various bare polymeric core N...

Silicon (Si) is the most promising next-generation anode material for lithium-ion batteries. However, it often suffers from a fast capacity fading due to the large volume changes during the lithiation/delithiation resulting in electrical contact loss between different components of the anode and eventually in battery fading. Mesoporous structure of...

Strict regulations are in place to control the effluents of mining sites and other industries. Heavy metal contamination of aquatic systems caused by leakages is difficult to mitigate as it takes time to detect and localize the leak. Dynamic sampling would drastically reduce the time to locate leakages and allow faster actions to reduce the impact...

Obesity is one of the major global threats to human health and risk factors for cardiometabolic diseases and certain cancers. GLP‐1 plays a major role in appetite and glucose homeostasis and recently the USFDA approved GLP‐1 agonists for the treatment of obesity and type 2 diabetes. GLP‐1 is secreted from enteroendocrine L‐cells in the distal part...

Functional colloidal nanoparticles capable of converting between various energy types are finding an increasing number of applications. One of the relevant examples concerns light-to-heat-converting colloidal nanoparticles that may be useful for localized photothermal therapy of cancers. Unfortunately, quantitative comparison and ranking of nanohea...

Nuclear medicine imaging plays an important role in nanomedicine. However, it is still challenging to develop a versatile platform to make the nonviral nanovectors used in cancer therapy biotraceable. In the present study, a robust approach to radiolabel inorganic nanovectors for SPECT and PET imaging was developed. The approach was based on the bi...

Lithium-ion batteries (LIBs) are the most preferred energy storage devices today for many high-performance applications. Recently, concerns about global warming and climate change have increased the need and requirements for LIBs used in electric vehicles, and thus more advanced technologies and materials are urgently needed. Among the anode materi...

Silicon is the most promising anode material for next-generation lithium-ion batteries (LIBs) due to its high theoretical specific capacity and safe electrochemical potential. Among the different Si materials, mesoporous Si has attracted attention as the pores can accommodate the volume expansion during cycling, thus leading to stable battery cycli...

Immunotherapy, in particular immune checkpoint blockade (ICB) therapy targeting the programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) axis, has remarkably revolutionized cancer treatment in the clinic. Anti-PD-1/PD-L1 therapy is designed to restore the antitumor response of cytotoxic T cells (CTLs) by blocking the interaction be...

Background: Post-traumatic osteoarthritis is a frequent joint disease in the horse. Currently, equine medicine lacks effective methods to diagnose the severity of chondral defects after an injury. Objectives: To investigate the capability of dual-contrast-enhanced computed tomography (dual-CECT) for detection of chondral lesions and evaluation o...

Many efforts have recently concentrated on constructing and developing nanoparticles (NPs) as promising thermal agent for optical hyperthermia and photothermal therapy. However, thermal energy transfer in biological tissue is a complex process involving different mechanisms such as conduction, convection, radiation. Therefore, having information ab...

Production of scandium (Sc) is a complicated process largely because the Sc concentration in ores is typically low in comparison to other types of metals. Therefore, typical extraction processes, such as solvent extraction and precipitation, that are used for separation and purification of leach liquors are inefficient. Adsorption/desorption is a g...

The number of in vitro , ex vivo , and in vivo studies on porous silicon (PSi) nanoparticles for biomedical applications has extensively increased during the last decade. The focus of the reports has been on the carrier properties of PSi concerning the therapy aspect due to its several beneficial nanovector characteristics including high payload ca...

Scope Nutrients stimulate the secretion of glucagon-like peptide-1 (GLP-1), an incretin hormone, secreted from enteroendocrine L-cells which decrease food intake. Thus, GLP-1 analogs are approved for the treatment of obesity yet cost and side effects limit their use. L-cells are mainly localized in the distal ileum and colon, which hinders the util...

Naturally-occurring polymers have a variety of sources such as plants and animals extracted using various physicochemical or biological methods. Based on their monomeric units, biopolymers can be classified as follows: polynucleotides, polysaccharides, and polypeptides. Biopolymers are renewable and have attracted significant attention in the last...

Over the years, nanobiopolymers produced by living organisms, as well as microbial nanobiopolymers, have gained a wide scientific and engineering attraction mainly due to the benefits related to sustainability and biodegradability. Several mechanical, chemical and biological methods have been employed for the fabrication of these nanobiopolymers an...

Black porous silicon nanoparticles (BPSi NPs) are known as highly efficient infrared light absorbers that are well-suitable for photothermal therapy (PTT) and photoacoustic imaging (PAI). PTT and PAI require a sufficient number of effectively light-absorbing NPs to be accumulated in tumor after intravenous administration. Herein, biodistribution of...

Nanostructured silicon carbide possesses superior properties such as excellent hardness, high chemical stability, large surface area and good sintering ability at relatively low temperatures compared to bulk silicon carbide. However, its synthesis with conventional methods is still challenging. In the present study, we produced nanostructured silic...

Freeze drying is known to be able to produce an amorphous product, but this approach has been mostly used with water-based media. With APIs which are virtually water insoluble, a more appropriate freeze-drying medium would be an organic solvent. Little is known about this approach in terms of forming a stable freeze-dried amorphous product stabiliz...

Anthropogenic activities such as mining and ore beneficiation generate large amounts of uranium-contaminated wastewater. The metal is radioactive and toxic; therefore, it needs to be removed to protect the environment and human health. Adsorption is a viable method to remove uranium from wastewater because of the low energy consumption and ability...

Inorganic photothermal agents (PTAs) have attracted considerable attention in cancer theranostics due to their unique features such as high photothermal conversion efficacy, excellent photothermal stability, and straightforward functionalization. The first part of this Review summarizes progress in methods for synthesizing PTAs, then considers in v...

Injection of H 2 O 2 to control both the rate and extent of etching allowed us to discover a new regime of MACE with extremely small quantities of deposited metal as a catalyst: low-load MACE (LL-MACE). ¹ The structure of particles subjected to LL-MACE is completely different compared to conventional MACE. Si nanowires and mesoporous micro- or nano...

Nanostructured silicon carbide (SiC) is an exceptional material with numerous applications, for example, in catalysis, biomedicine, high-performance composites, and sensing. In this study, a fast and scalable method of producing nanostructured SiC from plant materials by magnesiothermic reduction via self-propagating hightemperature synthesis (SHS)...

The recently discovered low-load metal-assisted catalytic etching (LL-MACE) creates nanostructured Si with controllable and variable characteristics that distinguish this technique from the conventional high-load variant. LL-MACE employs 150 times less metal catalyst and produces porous Si instead of Si nanowires. In this work, we demonstrate that...

Complex experimental design is a common problem in the preparation of theranostic nanoparticles, resulting in poor reaction control, expensive production cost, and low experiment success rate. The present study aims to develop PEGylated bismuth (PEG-Bi) nanoparticles with a precisely controlled one-pot approach, which only contains methoxy[(poly(et...

Batteries are commonly considered one of the key technologies to reduce carbon dioxide emissions caused by the transport, power, and industry sectors. We need to remember that not only the production of energy needs to be realized sustainably, but also the technologies for energy storage need to follow the green guidelines to reduce the emission of...

β-Lactam–resistant (BLR) Gram-negative bacteria that are difficult or impossible to treat are causing a global health threat. However, the development of effective nanoantibiotics is limited by the poor understanding of changes in the physical nature of BLR Gram-negative bacteria. Here, we systematically explored the nanomechanical properties of a...

Thermal isoeffect dose (TID) is a widely applied concept to evaluate the safety of medical devices that can expose patients to heat. However, it has rarely been used in photothermal therapy (PTT), where nanoparticles are used as light absorbers. Utilizing TID in an appropriate way would make it feasible to compare the results obtained with differen...

Generally, large-scale production of graphene is currently not commercially viable due to expensive raw materials, complexity and the high-energy consumption of the processes currently used in the production. The use of biomass precursors and energy efficient procedures for carbonization have been proposed to reduce the cost of the graphene materia...

Silicon is a promising alternative anode material for LIBs because it has ten times higher capacity than the currently used graphite giving the possibility to even double to capacity of the total battery cell. The high specific capacity is essential in the electric vehicles and portable electronic devices. However, silicon anodes are unstable durin...

Background Novel strategy and treatment methods for obesity and metabolic diseases are urgently needed. Various nutrients such as carbohydrate, fat, and proteins are involved in meal‐stimulated Glucagon like peptide‐1 (GLP‐1) release. GLP‐1 plays critical roles in maintaining euglycemia and controlling appetite, however it has a very short half‐lif...

Metal-assisted catalytic etching (MACE) involving Ag deposited on Si particles has been reported as a facile method for the production of Si nanowires (Si NWs). We show that the structure of Si particles subjected to MACE changes dramatically in response to changing the loading of the Ag catalyst. The use of acetic acid as a surfactant and controll...

Magnetic resonance imaging examinations are frequently carried out using contrast agents to improve the image quality. Practically all clinically used contrast agents are based on paramagnetic metals and lack in selectivity and specificity. A group of stable organic radicals, nitroxides, has raised interest as new metal-free contrast agents for MRI...

Polyethylene glycol (PEG) has been successfully used for improving circulation time of several nanomaterials but prolonging the circulation of porous silicon nanoparticles (PSi NPs) has remained challenging. Here, we report a site specific radiolabeling of dual-PEGylated thermally oxidized porous silicon (DPEG-TOPSi) NPs and investigation of influe...

Scandium has several applications in advanced technology, but its wider utilization is restricted by the limited supply. Scandium exists in low concentration in ores and, therefore, the conventional extraction methods are difficult, uneconomical, and often hazardous to the environment. Adsorption is more sustainable method to extract scandium, beca...

Mesoporous silicon (PSi) is an emerging nanomaterial studied in e.g. biomedical, sensor and energy applications. In many applications, a major obstacle in its commercial use is the instability of its surfaces, especially when functionalized with organic molecules. In the present work, we introduce a surface functionalization method for PSi, in whic...

Early degenerative changes of articular cartilage are detected using contrast-enhanced computed tomography (CT) with a cationic contrast agent (CA). However, cationic CA diffusion into degenerated cartilage decreases with proteoglycan depletion and increases with elevated water content, thus hampering tissue evaluation at early diffusion time point...

Novel treatment methods for obesity are urgently needed due to the increasing global severity of the problem. Gastrointestinal hormones, such as GLP-1 and PYY, are secreted by the enteroendocrine cells, playing a critical role in regulating food intake. Digested nutrients trigger the secretion of these hormones, which have a very short half-life. α...

The atomic-scale structure of amorphous SBA-15 materials with different pore sizes (6.7–12.7 nm) was investigated using pair distribution functions calculated from the X-ray total scattering data. The data was collected with a laboratory X-ray powder diffraction instrument instead of a synchrotron often considered necessary for pair distribution fu...

The presence of nanoparticles lowers the levels of ultrasound (US) intensity needed to achieve the therapeutic effect and improves the contrast between healthy and pathological tissues. Here, we evaluate the role of two main mechanisms that contribute to the US-induced heating of aqueous suspensions of biodegradable nanoparticles (NPs) of mesoporou...

The inability of traditional chemotherapeutics to reach cancer tissue reduces the treatment efficacy and leads toadverse effects. A multifunctional nanovector was developed consisting of porous silicon, superparamagneticiron oxide, calcium carbonate, doxorubicin and polyethylene glycol. The particles integrate magnetic propertieswith the capacity to r...

Porous silicon (PSi) has attracted wide interest as a potential material for various fields of nanomedicine. However, until now, the application of PSi in photothermal therapy has not been successful due to its low photothermal conversion efficiency. In the present study, biodegradable black PSi (BPSi) nanoparticles were designed and prepared via a...

The exploitation of various inorganic nanoparticles as drug carriers and therapeutics is becoming increasingly common. The first issue to be considered with regard to the nanomaterials being utilized in medicine centers on their safety. The functionality of nanocarriers in real-life environments explains the enthusiasm for their use. Several functi...

Silicon is being increasingly studied as the next-generation anode material for Li-ion batteries because of its ten times higher gravimetric capacity compared with the widely-used graphite. While nanoparticles and other nanostructured silicon materials often exhibit good cyclability, their volumetric capacity tends to be worse or similar than that...

Characterization of porous samples containing mesopores larger than 10 nm in size is often difficult due to limitations of standard methods. In the present work thermoporometry (TPM) was introduced to address these challenges. Various probe liquids (water, n-heptane, cyclohexane and o-xylene) were previously applied for TPM characterization of meso...

When poor aqueous solubility of active pharmaceutical ingredients is encountered during a drug formulation process, the toolbox typically utilized contains pharmaceutical salts, co-crystals, solid dispersions, cyclodextrins, lipids, liposomes and nanocrystals etc. Especially in the pharmaceutical industry, the option which confers the greatest bene...

Despite extensive efforts to develop delivery systems for oral administration, subcutaneous (s.c.) injection remains the most common way to administer peptide drugs. To limit the number of frequent injections, sustained release systems that are easy to produce, suitable for various drugs, safe and biodegradable are urgently needed. Porous silicon (...

The current contrast agents utilized in ultrasound (US) imaging are based on microbubbles which, however, suffer from a short lifetime in the systemic circulation. The present study introduces a new type of contrast agents for US imaging based on bioresorbable Janus nanoparticles (NPs) that are able to generate microbubbles in situ under US radiati...