Vashisth, A. | Search bioRxiv

bioRxiv2026

Network Formation Dynamics in Thiol-ene Crosslinked Hyaluronic Acid Hydrogels: Design Principles for In Vitro Tissue Models

Hydrogels are widely used as three-dimensional cell culture systems to understand the impact of cellular mechanotransduction for tissue engineering applications. Photoinitiated thiol-ene click chemistry is a commonly utilized hydrogel crosslinking mechanism that provides spatial and temporal control over hydrogel network formation and resulting mesh size and compressive properties. Despite historically documented efficiency as step-growth reactions, these reactions do not always proceed as predicted. To understand the impact of cell confinement and microenvironmental mechanics on cellular function, thiol-ene network formation must be thoroughly characterized. To this end, the objective of this work was to investigate the crosslinking dynamics to determine hydrogel network formation as assessed via mesh size and mechanical properties using a pentenoate-functionalized hyaluronic acid thiol-ene reaction. Hydrogel parameters including polymer concentration and thiol:-ene crosslinker molar ratio were modulated (4, 6, or 8 polymer weight percent and 0.15:1, 0.5:1, or 1:1 molar ratio of thiol groups to reactive -ene groups) to tune network properties including shear storage modulus and relative mesh size. Molecular Dynamics (MD) simulations were used to simulate the thiol-ene crosslinking reaction and establish a method for predicting thiol-ene reaction efficiency. Lastly, the feasibility of this hydrogel system for in vitro modeling was confirmed via assessment of metabolic activity of encapsulated primary human meniscal cells.

bioengineering↗

bioRxiv2025

Nuclear Fetuin-A Drives Adipocyte Senescence via HIF-1 α During Obesity

Fetuin-A (FetA), a liver derived glycoprotein, has emerged from genome-wide association studies and epidemiological surveillance as a serum biomarker linked to obesity-driven type 2 diabetes mellitus (T2D), primarily due to its contribution to adipose tissue dysfunction. Here, we uncovered an eccentric role of nuclear FetA in visceral white adipocytes of obese T2D conditions. Hypoxia-inducible factor-1 (HIF-1) facilitates the nuclear translocation of FetA via direct interaction, a process that promotes the emergence of a senescence-associated secretory phenotype (SASP). While nuclear co-localization of FetA and HIF-1 strongly promotes adipocyte senescence, silencing FetA alone is sufficient to prevent senescence, even in conditions of HIF-1 overexpression or lipid-rich hypoxic stress. Although nuclear FetA does not directly bind to DNA, it enhances HIF-1 transcriptional activity, potentiating the activation of senescence markers such as {beta}-galactosidase and p53. Selective knockdown of FetA in obese mice notably reduced adipocyte senescence in visceral white adipose tissue (vWAT) and improved fasting glycemic control. Collectively, our findings reveal a previously unrecognized nuclear function for FetA in orchestrating adipocyte senescence in obesity, establishing nuclear FetA as a potential therapeutic target for obesity related metabolic diseases.

cell biology↗