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Creators/Authors contains: "Xiang, Yuanhui"

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  1. Free, publicly-accessible full text available March 20, 2025
  2. A transient mechanism to achieve gelation in host–guest supramolecular hydrogels is demonstrated by acidification and pH correctionviaindirect control from a biocatalytic enzyme network.

     
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    Free, publicly-accessible full text available January 1, 2025
  3. Abstract

    The management of diabetes in a manner offering autonomous insulin therapy responsive to glucose‐directed need, and moreover with a dosing schedule amenable to facile administration, remains an ongoing goal to improve the standard of care. While basal insulins with reduced dosing frequency, even once‐weekly administration, are on the horizon, there is still no approved therapy that offers glucose‐responsive insulin function. Herein, a nanoscale complex combining both electrostatic‐ and dynamic‐covalent interactions between a synthetic dendrimer carrier and an insulin analogue modified with a high‐affinity glucose‐binding motif yields an injectable insulin depot affording both glucose‐directed and long‐lasting insulin availability. Following a single injection, it is even possible to control blood glucose for at least one week in diabetic swine subjected to daily oral glucose challenges. Measurements of serum insulin concentration in response to challenge show increases in insulin corresponding to elevated blood glucose levels, an uncommon finding even in preclinical work on glucose‐responsive insulin. Accordingly, the subcutaneous nanocomplex that results from combining electrostatic‐ and dynamic‐covalent interactions between a modified insulin and a synthetic dendrimer carrier affords a glucose‐responsive insulin depot for week‐long control following a single routine injection.

     
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    Free, publicly-accessible full text available February 1, 2025
  4. Abstract

    Diabetes is one of the most pressing healthcare challenges facing society. Dysfunctional insulin signaling causes diabetes, leading to blood glucose instability and many associated complications. While the administration of exogenous insulin is then essential for achieving glucose control, issues with dosing accuracy and timing remain. Hydrogel‐based drug delivery systems have been broadly explored for controlled protein release, including for applications in long‐lasting and oral insulin delivery. More recently, efforts have focused on injectable hydrogels with glucose‐directed controlled release of insulin and glucagon, aiming for more autonomous and biomimetic approaches to blood glucose control. These materials typically use protein‐based sensing mechanisms or glucose binding by synthetic aryl boronates for glucose‐directed release. Despite advancements in this area, there remains a need for more precise timing of therapeutic availability to afford healthy blood glucose homeostasis, providing an opportunity for further research and innovation. This review summarizes the current state of hydrogel‐based delivery of insulin and glucagon, with insights into the potential benefits, future directions, and challenges that must be overcome to achieve clinical impact.

     
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  5. Abstract

    In an effort to augment the function of supramolecular biomaterials, recent efforts have explored the creation of hybrid materials that couple supramolecular and covalent components. Here, the benzenetricarboxamide (BTA) supramolecular polymer motif is modified to present a phenylboronic acid (PBA) in order to promote the crosslinking of 1D BTA stacks by PBA–diol dynamic‐covalent bonds through the addition of a multi‐arm diol‐bearing crosslinker. Interestingly, the combination of these two motifs serves to frustrate the resulting assembly process, yielding hydrogels with worse mechanical properties than those prepared without the multi‐arm diol crosslinker. Both systems with and without the crosslinker do, however, respond to the presence of a physiological level of glucose with a reduction in their mechanical integrity; repulsive electrostatic interactions in the BTA stacks occur in both cases upon glucose binding, with added competition from glucose with PBA–diol bonds amplifying glucose response in the hybrid material. Accordingly, the present results point to an unexpected outcome of reduced hydrogel mechanics, yet increased glucose response, when two disparate dynamic motifs of BTA supramolecular polymerization and PBA–diol crosslinking are combined, offering a vision for future preparation of glucose‐responsive supramolecular biomaterials.

     
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  6. Abstract

    The transient self‐assembly of molecules under the direction of a consumable fuel source is fundamental to biological processes such as cellular organization and motility. Such biomolecular assemblies exist in an out‐of‐equilibrium state, requiring continuous consumption of high energy molecules. At the same time, the creation of bioinspired supramolecular hydrogels has traditionally focused on associations occurring at the thermodynamic equilibrium state. Here, hydrogels are prepared from cucurbit[7]uril host–guest supramolecular interactions through transient physical crosslinking driven by the consumption of a reactive chemical fuel. Upon action from this fuel, the affinity and dynamics of CB[7]–guest recognition are altered. In this way, the lifetime of transient hydrogel formation and the dynamic modulus obtained are governed by fuel consumption, rather than being directed by equilibrium complex formation.

     
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  7. Abstract

    The transient self‐assembly of molecules under the direction of a consumable fuel source is fundamental to biological processes such as cellular organization and motility. Such biomolecular assemblies exist in an out‐of‐equilibrium state, requiring continuous consumption of high energy molecules. At the same time, the creation of bioinspired supramolecular hydrogels has traditionally focused on associations occurring at the thermodynamic equilibrium state. Here, hydrogels are prepared from cucurbit[7]uril host–guest supramolecular interactions through transient physical crosslinking driven by the consumption of a reactive chemical fuel. Upon action from this fuel, the affinity and dynamics of CB[7]–guest recognition are altered. In this way, the lifetime of transient hydrogel formation and the dynamic modulus obtained are governed by fuel consumption, rather than being directed by equilibrium complex formation.

     
    more » « less