Specific protein-protein interactions limit the cutaneous iontophoretic transport of interferon beta-1b and a poly-Arg interferon beta-1b analogue.

The first objective was to investigate the transdermal iontophoresis of interferon beta 1b (IFN); the second was to determine whether the addition of 10 Arg residues at the N-terminus, creating a highly charged poly-Arg analogue (Arg10-IFN), increased delivery. Cumulative permeation of IFN and Arg10-IFN after iontophoresis at 0.5 mA/cm2 for 8 h was 6.97 ± 4.82 and 9.55 ± 1.63 ng/cm2, respectively - i.e. >1000-fold less than that of ribonuclease A, cytochrome c and human basic fibroblast growth factor. Co-iontophoresis of acetaminophen showed that, in contrast to lysozyme, neither IFN nor Arg10-IFN interacted with skin to decrease convective solvent flow. Furthermore, there was no statistically significant difference between (i) iontophoretic delivery of IFN across intact or laser porated skin and (ii) passive or iontophoretic delivery of IFN across laser porated skin. Chromatographic characterisation supported the hypothesis that IFN was bound strongly to albumin. The formation of a ~86 kDa complex with albumin was probably responsible for the poor cutaneous delivery of IFN/Arg10-IFN despite the use of iontophoresis and/or laser microporation. Biopharmaceuticals might interact with specific proteins during iontophoretic transport and so decrease their (per)cutaneous delivery without affecting electroosmotic solvent flow, which is usually considered as a reliable marker to report on permeant binding during electrotransport across the skin.

PASylation technology improves recombinant interferon-ß1b solubility, stability, and biological activity.

Recombinant interferon-ß1b (IFN-ß1b) is an effective remedy against multiple sclerosis and other diseases. However, use of small polypeptide (molecular weight is around 18.5 kDa) is limited due to poor solubility, stability, and short half-life in systemic circulation. To solve this problem, we constructed two variants of PASylated IFN-ß1b, with PAS sequence at C- or N-terminus of IFN-ß1b. The PAS-modified proteins demonstrated 4-fold increase in hydrodynamic volume of the molecule combined with 2-fold increase of in vitro biological activity, as well as advanced stability and solubility of the protein in solution as opposed to unmodified IFN-ß1b. Our results demonstrate that PASylation has a positive impact on stability, solubility, and functional activity of IFN-ß1b and potentially might improve pharmacokinetic properties of the molecule as a therapeutic agent.

Assessment of Serum Nitrogen Species and Inflammatory Parameters in Relapsing-Remitting Multiple Sclerosis Patients Treated with Different Therapeutic Approaches.

The role of nitric oxide and its reactive derivatives (NO x ) is well known in the pathogenesis of multiple sclerosis, which is an inflammatory disease while NO x seems to be important in coordinating inflammatory response. The purpose of the present study was to assess serum NO x as one of the nitrogen species and inflammatory parameters in relapsing-remitting multiple sclerosis patients and to compare the effectiveness of various types of disease-modifying therapies that reduce nitric oxide and inflammatory biomarkers. Elevated NO x level was observed in patients who received the first-line disease-modifying therapy (interferons beta-1a and beta-1b) in comparison with the subjects treated with the second-line disease-modifying therapy (natalizumab; fingolimod) and healthy controls without significant differences in C-reactive protein and interleukin-1 beta. A negative correlation was observed between serum NO x level and the duration of multiple sclerosis confirmed in the whole study population and in subjects treated with the first-line agents. Only serum NO x , concentration could reveal a potential efficacy of disease-modifying therapy with a better reduction in NO x level due to the second-line agents of disease-modifying therapy.