Mainly designed and realized as a painless alternative to the hypodermic syringe, microneedle-based devices are currently approaching commercial market placement. The considerable academic and industrial investment in this technology is reflected by a multitude of papers published and patents registered every year, which is also a sign of a field in full fermentation. New materials and innovative methodologies are continuously exploited in search of the best performance at the lowest cost. For these reasons, an updated review, focused predominantly on the last year of scientific production, is a useful guideline in this rapidly changing panorama. This report provides a critical review of microneedle technologies presented in the very recent literature with a particular focus on those closest to the needs of the healthcare field. Although a few devices are already commercial, further effort is still needed to achieve complete clinical translation and therapeutic efficacy competitive with or superior to those of the devices used as standards and adopted by national health systems.

Facile surface modification of polyester films was performed via chemical solutions treatment. Surface hydrolysis was carried out by means of sodium hydroxide solutions, leading to the formation of carboxylate groups. Three commercial polyester films of 100 μm in thickness were used in this work: AryLite™, Mylar™, and Teonex™, hydrolysis time being the main modification parameter. FTIR-ATR analysis, topography and contact angle (CA) measurements, surface free energy (SFE) and T-Peel adhesion tests were carried out to characterize the modified films. A quantitative estimate of the carboxylates surface coverage as a function of treatment time was obtained through a supramolecular approach, i.e. the ionic self-assembly of a tetracationic porphyrin chromophore onto the film surface. The surface free energy and critical surface tension of the hydrolyzed polyesters was evaluated by means of Zisman, Saito, Berthelot and Owens-Wendt methods. It was shown that NaOH solution treatment increases roughness, polarity and surface free energy of polymers. As a result, T-Peel strengths for modified Mylar™ and Teonex™ films were respectively 2.2 and 1.8 times higher than that for the unmodified films, whereas AryLite™ adhesion test failed.

Microneedle devices could play the role of a painless door to the human body. These devices enable high performance in both drug delivery and diagnostic analysis. While there has been a strong effort by the healthcare industry and applied research laboratories, the microneedles platform has not yet reached commercial success in the global market. In this competitive frame, the simplest fabrication processes and the best performing products will rise to the top of the market. In article number 1900036, Luca De Stefano and co‐workers review recent advances in this field.

Designing the foam structures in terms of density and morphology gives the chance to tune their mechanical and functional properties to the specific application. Nowadays, this design has been leveled up by the introduction of graded foams which are characterized by spatially nonuniform densities and/or morphologies. Graded foams have proved superior compared to uniform one in numerous examples and loading conditions but in pure compressive loading, where properties such as the Young's modulus of graded foams are always inferior to uniform ones. When using sintered beads foams, macroscopic pure compression may induce local bending on the single bead, which can be exploited to induce stiffening. This thesis was investigated on both polystyrene and thermoplastic polyurethane samples made by foamed beads sintered in a cylindrical mold. The response to compressive tests of graded foams made by sintering beads having nonuniform cells structures was compared to the uniform counterparts. The results evidenced that, at same average density, foams had up to a 30% ca. of increase of the Young's modulus when the beads are characterized by a denser outer layer.

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