Kang, H.-W. | Search bioRxiv

bioRxiv2024

Precision Repair of Zone-Specific Meniscal Injuries Using a Tunable Extracellular Matrix-Based Hydrogel System

Meniscus injuries present significant therapeutic challenges due to their limited self-healing capacity and diverse biological and mechanical properties across meniscal tissue. Conventional repair strategies neglect to replicate the complex zonal characteristics within the meniscus, resulting in suboptimal outcomes. In this study, we introduce an innovative, age- and stiffness-tunable meniscus decellularized extracellular matrix (DEM)-based hydrogel system designed for precision repair of heterogeneous, zonal-dependent meniscus injuries. By synthesizing age-dependent DEM hydrogels, we identified distinct cellular responses: fetal bovine meniscus-derived DEM promoted chondrogenic differentiation, while adult meniscus-derived DEM supported fibrochondrogenic phenotypes. The incorporation of methacrylate hyaluronic acid (MeHA) further refined the mechanical properties and injectability of the DEM-based hydrogels. The combination of age-dependent DEM with MeHA allowed for precise stiffness tuning, influencing cell differentiation and closely mimicking native tissue environments. In vivo tests confirmed the biocompatibility of hydrogels and their integration with native meniscus tissues. Furthermore, advanced 3D bioprinting techniques enabled the fabrication of hybrid hydrogels with biomaterial and mechanical gradients, effectively emulating the zonal properties of meniscus tissue and enhancing cell integration. This study represents a significant advancement in meniscus tissue engineering, providing a promising platform for customized regenerative therapies across a range of heterogeneous fibrous connective tissues.

bioengineering↗

bioRxiv2022

Mechanistic insights of glucosome condensate formation by stochastic modeling approaches

Human liver-type phosphofructokinase 1 (PFKL) has been shown to play a scaffolder role to recruit and organize glycolytic and gluconeogenic enzymes into a multienzyme metabolic condensate, the glucosome, that regulates glucose flux in living human cells. However, it has been challenging to characterize which factors control phase separation of PFKL and so glucosome condensates in a living cell, thus hampering to understand a mechanism of reversible glucosome formation and its functional contribution to human cells. In this work, we developed a stochastic model in silico using the principal of Langevin dynamics to investigate how biological properties of PFKL contribute to the formation of glucosome condensates. Molecular dynamics simulation using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) revealed the importance of an intermolecular interaction between PFKLs, an effective concentration of PFKL at a region of interest, and a pre-organization of its own self-assembly in formation of PFKL condensates and control of their sizes. Such biological properties that define intracellular dynamics of PFKL appear to be essential for phase separation of PFKL and thus formation of glucosome condensates. Collectively, our computational study provides mechanistic insights of glucosome formation, particularly an initiation step through the formation of PFKL condensates in living human cells.

biochemistry↗