Removal of Peroxides from Functionalized Polyethylene Glycol (PEG) and Effects on the Stability and Sensitivity of Resulting PEGylated Conjugates

The removal of peroxides from commercial samples of PEG through freeze-drying can have positive effects on the stability and sensitivity of ROS-sensing conjugates made using the PEG. These data demonstrate the positive effects of a freeze-drying protocol on the ROS-sensing ability and stability in solution of these conjugates.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

A naked eye-invisible ratiometric fluorescent microneedle tattoo for real-time monitoring of inflammatory skin conditions

The field of portable healthcare monitoring devices has an urgent need for the development of real-time, noninvasive sensing and detection methods for various physiological analytes. Currently, transdermal sensing techniques are severely limited in scope (i.e., measurement of heart rate or sweat composition), or else tend to be invasive, often needing to be performed in a clinical setting. This study proposes a minimally invasive alternative strategy, consisting of using dissolving polymeric microneedles to deliver naked eye-invisible functional fluorescent ratiometric microneedle tattoos directly to the skin for real-time monitoring and quantification of physiological and pathological parameters. Reactive oxygen species are overexpressed in the skin in association with various pathological conditions. Here, one demonstrates for the first time the microneedle-based delivery to the skin of active fluorescent sensors in the form of an invisible, ratiometric microneedle tattoo capable of sensing reactive oxygen species in a reconstructed human-based skin disease model, as well as an in vivo model of UV-induced dermal inflammation. One also elaborates a universal ratiometric quantification concept coupled with a custom-built, multiwavelength portable fluorescence detection system. Fully realized, this approach presents an opportunity for the minimally invasive monitoring of a broad range of physiological parameters through the skin

Two-Photon Polymerisation 3D Printing of Microneedle Array Templates with Versatile Designs: Application in the Development of Polymeric Drug Delivery Systems

open access articlePurpose To apply a simple and flexible manufacturing technique, two-photon polymerisation (2PP), to the fabrication of microneedle (MN) array templates with high precision and low cost in a short time. Methods Seven different MN array templates were produced by 2PP 3D printing, varying needle height (900–1300 μm), shape (conical, pyramidal, cross-shaped and with pedestal), base width (300–500 μm) and interspacing (100–500 μm). Silicone MN array moulds were fabricated from these templates and used to produce dissolving and hydrogel-forming MN arrays. These polymeric MN arrays were evaluated for their insertion in skin models and their ability to deliver model drugs (cabotegravir sodium and ibuprofen sodium) to viable layers of the skin (ex vivo and in vitro) for subsequent controlled release and/or absorption. Results The various templates obtained with 2PP 3D printing allowed the reproducible fabrication of multiple MN array moulds. The polymeric MN arrays produced were efficiently inserted into two different skin models, with sharp conical and pyramidal needles showing the highest insertion depth values (64–90% of needle height). These results correlated generally with ex vivo and in vitro drug delivery results, where the same designs showed higher drug delivery rates after 24 h of application. Conclusion This work highlights the benefits of using 2PP 3D printing to prototype variable MN array designs in a simple and reproducible manner, for their application in drug delivery