Effect of particle functionalization and solution properties on the adsorption of bovine serum albumin and lysozyme onto silica nanoparticles.

Silica nanoparticles present an enormous potential as controlled drug delivery systems with high selectivity towards diseased cells. This application is directly related to the phenomenon of protein corona, characterized by the spontaneous adsorption of proteins on the nanoparticle surface, which is not fully understood. Here, we report an investigation on the influence of pH, ionic strength and temperature on the thermodynamics of interaction of bovine serum albumin protein (BSA) with non-functionalized silica nanoparticles (SiO2NPs). Complementary, we also investigated the ability of polyethylene glycol (PEG) and zwitterionic sulfobetaine (SBS) surface-modified nanoparticles to prevent the adsorption of BSA (protein negatively charged at physiological pH) and lysozyme (protein positively charged at physiological pH). We showed that BSA interaction with SiO2NPs is enthalpically governed. On the other hand, functionalization of silica nanoparticles with PEG and SBS completely prevented BSA adsorption. However, these functionalized nanoparticles presented a negative zeta potential and were not able to suppress lysozyme anchoring due to strong nanoparticle-protein electrostatic attraction. Due to the similarity of BSA with Human Serum Albumin, this investigation bears a resemblance to processes involved in the phenomenon of protein corona in human blood, producing information that is relevant for the future biomedical use of functionalized nanoparticles.

Portuguese recommendations for the use of biological therapies in patients with axial spondyloarthritis - 2016 update.

OBJECTIVE: To update the recommendations for the treatment of axial spondyloarthritis (axSpA) with biological therapies, endorsed by the Portuguese Society of Rheumatology. METHODS: These treatment recommendations were formulated by Portuguese rheumatologists based on literature evidence and consensus opinion. At a national meeting, the 7 recommendations included in this document were discussed and updated. A draft of the full text of the recommendations was then circulated and suggestions were incorporated. A final version was again circulated before publication and the level of agreement among Portuguese Rheumatologists was anonymously assessed using an online survey. RESULTS: A consensus was achieved regarding the initiation, assessment of response and switching of biological therapies in patients with axSpA. In total, seven recommendations were produced. The first recommendation is a general statement indicating that biological therapy is not a first-line drug treatment option and should only be used after conventional treatment has failed. The second recommendation is also a general statement about the broad concept of axSpA adopted by these recommendations that includes both non-radiographic and radiographic axSpA. Recommendations 3 to 7 deal with the definition of active disease (including the recommended threshold of 2.1 for the Ankylosing Spondylitis Disease Activity Score [ASDAS] or the threshold of 4 [0-10 scale] for the Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]), conventional treatment failure (nonsteroidal anti-inflammatory drugs being the first-line drug treatment), assessment of response to treatment (based on an ASDAS improvement  of at least 1.1 units or a BASDAI improvement of at least 2 units [0-10 scale] or at least 50%), and strategy in the presence of an inadequate response (where switching is recommended) or in the presence of long-term remission (where a process of biological therapy optimization can be considered, either a gradual increase in the interval between doses or a decrease of each dose of the biological therapy). CONCLUSION: These recommendations may be used for guidance in deciding which patients with axSpA should be treated with biological therapies. They cover a rapidly evolving area of therapeutic intervention. As more evidence becomes available and more biological therapies are licensed, these recommendations will have to be updated.

2011 Portuguese recommendations for the use of biological therapies in patients with psoriatic arthritis.

OBJECTIVE: To develop recommendations for the treatment of psoriatic arthritis (PsA) with biological therapies, endorsed by the Portuguese Society of Rheumatology. METHODS: These treatment recommendations were formulated by Portuguese rheumatologists based on literature evidence and consensus opinion. A draft of the recommendations was first circulated to all Portuguese rheumatologists and their suggestions were incorporated in the draft. At a national meeting the recommendations were discussed and all attending rheumatologists voted on the level of agreement for each recommendation. A second draft was again circulated before publication. RESULTS: A consensus was achieved regarding the initiation, assessment of response and switching biological therapies in patients with PsA. Specific recommendations were developed for several disease domains: peripheral arthritis, axial disease, enthesitis and dactylitis. CONCLUSION: These recommendations may be used for guidance in deciding which patients with PsA should be treated with biological therapies. They cover a rapidly evolving area of therapeutic intervention. As more evidence becomes available and more biological therapies are licensed, these recommendations will have to be updated.

Portuguese recommendations for the use of biological therapies in patients with axial spondyloarthritis--December 2011 update.

OBJECTIVE: To develop recommendations for the treatment of axial spondyloarthritis with biological therapies, endorsed by the Portuguese Society of Rheumatology. METHODS: These treatment recommendations were formulated by Portuguese rheumatologists based on literature evidence and consensus opinion. A draft of the recommendations and supporting evidence was first circulated to all Portuguese rheumatologists and their suggestions were incorporated in the draft. Secondly, at a national meeting the recommendations were presented, discussed and revised. Finally, the document resulting from this meeting was again circulated to all Portuguese rheumatologists, who anonymously voted online on the level of agreement with the recommendations. RESULTS: A consensus was achieved regarding the initiation, assessment of response and switching biological therapies in patients with axial spondyloarthritis. CONCLUSION: These recommendations may be used for guidance in deciding which patients with axial spondyloarthritis should be treated with biological therapies. They cover a rapidly evolving area of therapeutic intervention. As more evidence becomes available and more biological therapies are licensed, these recommendations will have to be updated.