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Electrospun PLGA microfibers with adequate intrinsic physical features (fiber alignment and diameter) have been shown to boost teno-differentiation and may represent a promising solution for tendon tissue engineering. However, the hydrophobic properties of PLGA may be adjusted through specific treatments to improve cell biodisponibility. In this study, electrospun PLGA with highly aligned microfibers were cold atmospheric plasma (CAP)-treated by varying the treatment exposure time (30, 60, and 90 s) and the working distance (1.3 and 1.7 cm) and characterized by their physicochemical, mechanical and bioactive properties on ovine amniotic epithelial cells (oAECs). CAP improved the hydrophilic properties of the treated materials due to the incorporation of new oxygen polar functionalities on the microfibers' surface especially when increasing treatment exposure time and lowering working distance. The mechanical properties, though, were affected by the treatment exposure time where the optimum performance was obtained after 60 s. Furthermore, CAP treatment did not alter oAECs' biocompatibility and improved cell adhesion and infiltration onto the microfibers especially those treated from a distance of 1.3 cm. Moreover, teno-inductive potential of highly aligned PLGA electrospun microfibers was maintained. Indeed, cells cultured onto the untreated and CAP treated microfibers differentiated towards the tenogenic lineage expressing tenomodulin, a mature tendon marker, in their cytoplasm. In conclusion, CAP treatment on PLGA microfibers conducted at 1.3 cm working distance represent the optimum conditions to activate PLGA surface by improving their hydrophilicity and cell bio-responsiveness. Since for tendon tissue engineering purposes, both high cell adhesion and mechanical parameters are crucial, PLGA treated for 60 s at 1.3 cm was identified as the optimal construct.

Since its identification in the early 1970s, artemisinin, as well as semi-synthetic derivatives and synthetic trioxanes, have been used in malaria therapy. Reduction of artemisinin by NaBH4 produced dihydroartemisinin (DHA), and yielded a new stereochemically labile centre at C-10, which, in turn, provided two interconverting lactol hemiacetal epimers (namely alpha and beta), whose rate of interconversion depends on buffer, pH, and solvent polarity. Since interconversion of the two epimers occurred on a chromatographic time-scale, this prompted a thorough investigation of the phenomenon as a crucial requisite of any analytical method aimed at quantitating this family of drugs. In this critical review we discuss the current importance of the on-column epimerization of DHA in the development of analytical methods aimed at quantifying the drug, with the purpose of identifying the optimal conditions to minimize on-column epimerization while achieving the best selectivity and efficiency of the overall separation.