Laser transparent multiplexed SERS microneedles for in situ and real-time detection of inflammation

It is a significant challenge to perform painless invasive detection of inflammation progression in relation to the evolution of pH, redox potential, and reactive oxygen species (ROS) levels in an in situ and real-time manner. In this work, polydopamine-modified, silver nanoparticle-decorated poly (methyl methacrylate) microneedles (AgNPs@PDA@MNs) have been developed as a multiplexed surface enhanced Raman scattering (SERS) diagnostic platform. Using rhodamine 6G as the Raman signal molecule, the AgNPs@PDA@MNs demonstrated a significant enhancement with reasonable linearity in the range of 10^-3-10^-9 mol/L and the limit of detection is 1.0 × 10^-10 mol/L 4-mercaptobenzoic acid, anthraquinone-2-carboxylic acid and para-aminothiophenol were covalently anchored on AgNPs@PDA@MNs SERS substrate. I₁₁₄₃/I₁₁₈₃, I₁₆₀₆/I₁₆₆₇ and I₁₁₄₃/I₁₀₇₇ were used as assay standards for pH, redox potential and ROS level detection, respectively. The SERS multiplexed transparent microneedles (SERS mtMNs) linearly responded to pH in the range of 4.0-8.0, redox potential in the range of 417.0-599.8 mV, and ROS levels in the range of 0-480 ng/mL, demonstrating a significant ability to detect complex inflammation in vivo, in situ and in real-time.

Bioinspired ketoprofen-incorporated polyvinylpyrrolidone/polyallylamine/ polydopamine hydrophilic pressure-sensitive adhesives patches with improved adhesive performance for transdermal drug delivery

Inspired by the natural mussel adhesive mechanism, three different materials-polydopamine (PDA), polyvinylpyrrolidone (PVP), and polyallylamine (PAM)-were used to make innovative pressure-sensitive adhesives (PSAs) for transdermal delivery of ketoprofen. PDA was synthesized under alkaline conditions using a self-polymerization reaction and was exploited as a cross-linking agent due to its biocompatibility. The adhesive performance, physicochemical properties, drug content, and drug permeation through the skin were examined. Moreover, in vivo skin irritation and skin adhesion performance were investigated. PVP/PAM/PDA PSAs showed a significantly higher adhesion to human skin compared with commercial patches owing to the interaction between the catechol groups presented on the patches and the skin. In addition, the patches were stable for six months. Consequently, the PVP/PAM/PDA patches exhibited outstanding tissue adhesiveness, enabling universal tissue adherence while causing no skin tissue irritation or inflammatory reaction.