Fabrication of pH-degradable supramacromolecular microgels with tunable size and shape via droplet-based microfluidics.

This study presents a versatile method to synthesize stimuli-responsive microgels with supramolecular cross-links exhibiting tunable size and shape via droplet-based microfluidics. The natural polyphenol tannic acid (TA) is used to cross-link poly(N-vinylcaprolactam) (PVCL) chains in aqueous droplets by the formation of hydrogen bonds and hydrophobic interactions between the phenolic groups of TA and the carbonyl group and the hydrophobic segments of lactam ring of PVCL chains. The obtained microgels exhibit diameters in the range of 130-150µm in swollen state in aqueous solution. Synthesized microgels exhibit pH-responsive behavior: at low pH microgels deswell and shrink due to the protonation of phenolic groups and enhanced hydrophobic interactions; at high pH microgels swell and disintegrate due to the deprotonation of phenolic groups and destruction of hydrogen bonds with PVCL chains. Additionally, we present supramacromolecular microgels in cylindrical shape with different aspect ratios using a new design of microfluidic chip by varying flow rates at high concentration of the prepolymerized precursor combined with rapid pH-triggered on-chip gelation. Furthermore, developed synthesis methodology allows on-chip encapsulation of colloidal objects into large supramacromolecular microgels during the cross-linking step. The complete and fast release of objects by pH-triggered degradation indicates that the pH-responsive supramacromolecular microgels can be used for controlled loading/release of various payloads, like probiotics. Moreover, cell studies of L929 fibroblast clearly show the biocompatibility of the microgels.

Early prelingual auditory development in Italian infants and toddlers analysed through the Italian version of the Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS).

PURPOSE: To evaluate the reliability and validity of the Italian version of the Infant-Toddler Meaningful Auditory Integration Scale (I-IT-MAIS), and to assess the normal trajectory of early prelingual auditory (EPLAD) development from birth to 24 months in a group of normal-hearing Italian children using the I-IT-MAIS. METHODS: The study consisted of four phases: item generation, reliability analysis, assessment of the normal trajectory for EPLAD, and validity analysis. A group of 120 normal-hearing children and a group of 31 deaf children wearing hearing aids and on a waiting list for cochlear implantation were enrolled. All the parents completed the I-IT-MAIS. Sixty of them completed the I-IT-MAIS twice, 2 weeks apart, for test-retest reliability analysis. The I-IT-MAIS scores were used to assess the normal trajectory of EPLAD development from birth to 24 months in normal-hearing children. For criterion validity analysis, the I-IT-MAIS scores were correlated with production of infant scale evaluation (PRISE) scores in 60 normal-hearing children. For discriminant validity analysis, the I-IT-MAIS scores obtained in normal and deaf children were compared. RESULTS: Internal consistency of I-IT-MAIS was satisfactory as well as individual item reliability, test-retest reliability, and discriminant validity. EPLAD development in normal-hearing Italian-speaking children was evaluated. As far as the criterion validity of the I-IT-MAIS is concerned, a strong correlation between I-IT-MAIS and PRISE scores was found. CONCLUSION: I-IT-MAIS is reliable and valid. Its application is recommended for clinical practice and outcome research.