Joakim Riikonen

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Utilization of inorganic mesoporous materials in formulations of poorly water-soluble drugs to enhance their dissolution and permeation behavior is a rapidly growing area in pharmaceutical materials research. The benefits of mesoporous materials in drug delivery applications stem from their large surface area and pore volume. These properties enable the(More)
We have developed a gas-phase nanoparticle generator that produces stable and well-defined size distributions for TiO(2). The online analyses of the gas-phase compounds and total number concentration of the generated particles as well as the off-line analysis of the filter samples confirmed the stability of the production. The major advantage of this(More)
Six different types of mesoporous silicon microparticles were prepared to evaluate the effect of surface treatment and pore sizes on their properties as drug carriers. The studied porous silicon particles were as-anodized, thermally carbonized (TCPSi) and thermally oxidized (TOPSi) in addition to three novel ones: annealed TCPSi, annealed TOPSi and(More)
Mesoporous silicon microparticles with three various surface chemistries and eight different average pore diameters for each surface modification, ranging from 11 to 75 nm, were loaded with ibuprofen. The loaded batches were characterized using thermal analysis and nitrogen sorption. Three thermodynamically different states of ibuprofen were found in the(More)
We report here the in vitro cytotoxicity of mesoporous silicon (PSi) microparticles on the Caco-2 cells as a function of particle size fractions (1.2-75 microm), particle concentration (0.2-4 mg ml(-1)) and incubation times (3, 11 and 24 h). The particle size (smaller PSi particles showed higher cytotoxicity) and the surface chemistry treatment of the PSi(More)
Insect cold hardiness is often mediated by low molecular weight cryoprotectants, such as sugars, polyols, and amino acids (AA). While many free-living northern insects must cope with extended periods of freezing ambient temperatures (Ta), the ectoparasitic deer ked Lipoptena cervi imago can encounter subfreezing Ta only during a short autumnal period(More)
Mesoporous materials are promising candidates for improving dissolution rate of poorly water-soluble drugs in vitro and their bioavailability in vivo. In the present study, sixteen batches of celecoxib-loaded PSi particles with pore sizes ranging from 17 to 58 nm and celecoxib content from 5 to 36 w-% were prepared and a detailed physicochemical(More)
Peptides may represent potential treatment options for many severe illnesses. However, they need an effective delivery system to overcome rapid degradation after their administration. One possible way to prolong peptide action is to use particulate drug delivery systems. In the present study, thermally hydrocarbonized mesoporous silicon (THCPSi)(More)
Peptide molecules can improve the treatment of a number of pathological conditions, but due to their physicochemical properties, their delivery is very challenging. The study aim was to determine whether nanostructured porous silicon could sustain the release and prolong the duration of action of a model peptide Melanotan II (MTII). Thermally(More)
Peptides have long been recognized as a promising group of therapeutic substances to treat various diseases. Delivery systems for peptides have been under development since the discovery of insulin for the treatment of diabetes. The challenge of using peptides as drugs arises from their poor bioavailability resulting from the low permeability of biological(More)