In recent decades, mass spectrometry techniques, particularly when combined with separation methods such as high-performance liquid chromatography, have become increasingly important in pharmaceutical, bio-analytical, environmental, and food science applications because they afford high selectivity and sensitivity. However, mass spectrometry has limitations due to the matrix effects (ME), which can be particularly marked in complex mixes, when the analyte co-elutes together with other molecules, altering analysis results quantitatively. This may be detrimental during method validation, negatively affecting reproducibility, linearity, selectivity, accuracy, and sensitivity. Starting from literature and own experience, this review intends to provide a simple guideline for selecting the best operative conditions to overcome matrix effects in LC-MS techniques, to obtain the best result in the shortest time. The proposed methodology can be of benefit in different sectors, such as pharmaceutical, bio-analytical, environmental, and food sciences. Depending on the required sensitivity, analysts may minimize or compensate for ME. When sensitivity is crucial, analysis must try to minimize ME by adjusting MS parameters, chromatographic conditions, or optimizing clean-up. On the contrary, to compensate for ME analysts should have recourse to calibration approaches depending on the availability of blank matrix. When blank matrices are available, calibration can occur through isotope labeled internal standards and matrix matched calibration standards; conversely, when blank matrices are not available, calibration can be performed through isotope labeled internal standards, background subtraction, or surrogate matrices. In any case, an adjusting of MS parameters, chromatographic conditions, or a clean-up are necessary.

Owing to their high versatility from chemical and processing perspectives and hence their capability of being tailored for required properties, epoxy resins are used in a wide range of applications ranging from general use to high performing materials. Most of the applications though also require conformation

Osteoarthritis (OA), due to cartilage degeneration, is one of the leading causes of disability worldwide. Currently, there are not efficacious therapies to reverse cartilage degeneration. In this study we evaluated the potential of hybrid hydrogels, composed of a biodegradable and thermosensitive triblock copolymer cross-linked via Michael addition to thiolated hyaluronic acid, in contrasting inflammatory processes underlying OA. Hydrogels composed of different w/w % concentrations of hyaluronan were investigated for their degradation behavior and capacity to release the polysaccharide in a sustained fashion. It was found that hyaluronic acid was controllably released during network degradation with a zero-order release kinetics, and the release rate depended on cross-link density and degradation kinetics of the hydrogels. When locally administered in vivo in an OA mouse model, the hydrogels demonstrated the ability to restore, to some extent, bone remineralization, proteoglycan production, levels of Sox-9 and Runx-2. Furthermore, the downregulation of proinflammatory mediators, such as TNF-α, NFkB, and RANKL and proinflammatory cytokines was observed. In summary, the investigated hydrogel technology represents an ideal candidate for the potential encapsulation and release of drugs relevant in the field of OA. In this context, the hydrogel matrix could act in synergy with the drug, in reversing phenomena of inflammation, cartilage disruption, and bone demineralization associated with OA.

Neurodegenerative diseases, including Parkinson's and Alzheimer's, are a heterogeneous group of brain disorders characterized by the progressive degeneration of the structure and function of the central or peripheral nervous system. It is thought that the number of people affected by these pathologies will increase in future decades, particularly in the more economically developed countries, where the populations are experiencing a demographic shift towards older ages. For many of these pathologies, and in particular for Alzheimer's disease, no effective treatments are available, and the consequent economic and social costs are very high. Scientific progress in recent decades has provided a better understanding of the genetic and biological mechanisms responsible for these neurodegenerative diseases, and offers the hope for new therapeutic approaches in the near future. Meanwhile, the lack of effective therapies for these diseases has caused researchers to focus attention on the powerful opportunity of prevention, seen on the one hand as a series of healthcare measures and patient behaviors, and on the other hand as treatments exploiting several molecules or compounds with the potential to slow down the appearance of the first signs of pathology or even to prevent these diseases. Among these, curcumin, flavonoids, such as quercetin, Gingko biloba, and folic acid have attracted the attention of scientists, and ways are being explored to increase their effectiveness and bioavailability in the site of action. Most molecules suffer from problems of solubility, or bioavailability, or the ability to cross the blood brain barrier, and one solution to this limitation being explored is nanomedicine. Polymeric nanoparticles, as well as liposomes, and functionalized nanosystems may overcome several bioavailability limits of active molecules and increase their effectiveness in the brain. This review offers an overview of small molecules that may prove effective in preventing neurodegenerative diseases, and describes the strategies in nanomedicine that are being studied to improve their bioavailability.

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