Combined reversible addition-fragmentation chain transfer (RAFT) and chemoselective "click" chemistry are used for assembling two polymeric chains into a hybrid network capable to respond simultaneously or separately to different external stimuli. An azido-derivative of hyaluronate is clicked together with a new telechelic RAFT-generated p(NiPAAm), carrying a propargyl function at both ends, suitable as macromolecular "clickable" cross-linker with controlled molecular weight. This hybrid system displays a multiresponsive behavior versus temperature, pH, and ionic strength, maintaining cumulative as well as separate sensitivities to the external stimuli. Hyaluronidase catalyzed degradation of the hydrogels, mimicking the extracellular matrix degradation process, is an additional asset for the use of this class of hydrogels as scaffold. Tumor cells, HT-29, grow on the surface of these hybrid hydrogels more than the healthy ones, as NIH3T3. This finding opens a road to micro- and nano-devices based on hyaluronic acid as a promising biopolymer to pursue localized drug delivery.
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http://dx.doi.org/10.1002/mabi.201400021 | DOI Listing |
Nat Commun
December 2024
Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, School of Medicine, Tongji University, Shanghai, China.
Penetrating orocutaneous or oropharyngeal fistulas (POFs), severe complications following unsuccessful oral or oropharyngeal reconstruction, remain complex clinical challenges due to lack of supportive tissue, contamination with saliva and chewed food, and dynamic oral environment. Here, we present a Janus hydrogel adhesive (JHA) with asymmetric functions on opposite sides fabricated via a facile surface enzyme-initiated polymerization (SEIP) approach, which self-entraps surface water and blood within an in-situ formed hydrogel layer (RL) to effectively bridge biological tissues with a supporting hydrogel (SL), achieving superior wet-adhesion and seamless wound plugging. The tough SL hydrogel interlocked with RL dissipates energy to withstand external mechanical stimuli from continuous oral motions like chewing and swallowing, thus reducing stress-induced damage.
View Article and Find Full Text PDFPurpose: This study aimed to explore the potential application of NAO in guiding patients through rehabilitative exercises using external audiovisual stimuli, focusing on temporospatial control in terms of range of motion (ROM), execution time and movement smoothness.
Methods: This is a preliminary analysis involving ten healthy volunteers and two patients with shoulder musculoskeletal disorders. The protocol was developed in two phases (III and IV) with different ROM limits and including flexion-extension (FE), external-rotation (ER) and internal-rotation (IR) exercises, performed at two speeds and both with and without NAO assistance.
Spectrochim Acta A Mol Biomol Spectrosc
December 2024
Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India. Electronic address:
Sialic acid, a negatively charged nine-carbon monosaccharide, is mainly located at the terminal end of glycan chains on glycoproteins and glycolipids of cell surface and most secreted proteins. Elevated levels of sialylated glycans have been known as a hallmark in numerous cancers. As a result, sialic acid acts as a useful and accessible cancer biomarker for early cancer detection and monitoring the disease development during cancer treatment which is crucial in elevating the survival rate.
View Article and Find Full Text PDFSleep Breath
December 2024
Department of Anatomy, Faculty of Medicine, Istanbul Medeniyet University, Istanbul, Türkiye.
Objective: This study investigated the effects of sleep deprivation (SD) on balance after normal sleep, 24 h of SD, and subsequent rest under eyes-open (EO) and eyes-closed (EC) conditions. Our aim was to ascertain whether the reduced efficiency of balance control following SD is generalized or selective.
Method: Nineteen participants (12 females, 7 males) completed the Pittsburgh Sleep Quality Index (PSQI).
Gels
December 2024
"Petru Poni" Institute of Macromolecular Chemistry, Grigore Ghica Voda Alley 41A, 700487 Iasi, Romania.
An imbalance in the body's pH or temperature may modify the immune response and result in ailments such as autoimmune disorders, infectious diseases, cancer, or diabetes. Dual pH- and thermo-responsive carriers are being evaluated as advanced drug delivery microdevices designed to release pharmaceuticals in response to external or internal stimuli. A novel drug delivery system formulated as hydrogel was developed by combining a pH-sensitive polymer (the "biosensor") with a thermosensitive polymer (the delivery component).
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