Seong-Min Jo

Enzyme cascade reactions, where the product of one enzyme serves as the substrate for another, are fundamental to cellular metabolism and essential for constructing efficient multi‐enzyme systems. Spatial confinement of sequential enzymes can enhance cascade efficiency through proximity effects and substrate channeling, mimicking the organization of natural metabolic pathways. Here, we coencapsulated glucose oxidase (GOX) and horseradish peroxidase (HRP) within silica nanocapsules (SiNCs) using an enzyme‐friendly synthesis method. The encapsulated enzymes retained high catalytic activity, and Michaelis‐Menten kinetics analysis revealed decreased Km for GOX, indicating enhanced substrate affinity under confinement. The coencapsulated system demonstrated faster cascade kinetics compared to spatially separated enzyme configurations, providing direct evidence for the beneficial effects of enzyme proximity on intermediate transfer. Enhanced thermal stability of confined enzymes was also observed, presumably due to preserved hydration shells. This platform enables quantitative studies on enzyme behavior under nanoscale confinement, offering insights into the biochemical principles governing multi‐enzyme cascade systems in both natural and artificial environments.

So-Hee Park and Seong-Min Jo. J. Microbiol. Biotechnol. 2026;36:1-11. https://doi.org/10.4014/jmb.2604.04021

Coenzyme regeneration is essential for oxidoreductase‐based biocatalysis, yet integrating enzymatic and photocatalytic systems remains challenging due to ROS‐mediated enzyme inactivation. Here, we developed a metabolic‐inspired compartmentalization strategy that enables sustainable NAD ⁺ /NADH cycling by mimicking the spatial organization of cellular redox metabolism. Glucose dehydrogenase (GDH) was encapsulated within silica nanoparticles, exploiting the intrinsic instability of hydroxyl radicals and their limited diffusion distance to shield the enzyme from TiO ₂ ‐generated ROS while preserving substrate and cofactor accessibility. The encapsulated GDH maintained catalytic competence and achieved five consecutive coenzyme regeneration cycles, whereas the free enzyme lost activity after a single photocatalytic exposure. Beyond cofactor recycling, NADH generated by this system functioned as an endogenous antioxidant, protecting cells from photocatalytic oxidative stress. This work demonstrates that principles from cellular biochemistry, including compartmentalization and redox homeostasis, can be translated into artificial systems for sustainable biocatalysis and cell protection.

Da-Hye Ryu, Dong-Hyun You, Myung Kyung Jung, Ji-Soo Lee, Sohee Park, Cheol Am Hong, Yiseul Ryu, Joong-jae Lee, and Seong-Min Jo. Korean Society for Biotechnology and Bioengineering Journal 2025;40:229-41. https://doi.org/10.7841/ksbbj.2025.40.3.229

The dispersion of titanium dioxide (TiO₂) determines the performance of TiO₂-based formulations in cosmetic and coating applications. In particular, the chemical and structural characteristics of the surfactants used to prepare TiO₂ dispersions are significant. However, the influence of surfactants on TiO₂ dispersion quality has not been systematically investigated. In this study, we observed the effects of the ionic character of commercial surfactants on the dispersion stability and UV-blocking efficacy of TiO₂. Among the experimental surfactant groups, anionic sodium dodecyl sulfate was efficient in stabilizing TiO₂ as a water-in-oil formulation and enhancing its UV-blocking efficacy. Furthermore, an anionic fatty acid as a surfactant with a longer alkyl chain length was sufficient to stabilize the TiO₂ formulation, which also displayed the highest UV-blocking efficacy, comparable to the values of commercial TiO₂-based cosmetic products.

Wound dressings are widely used to protect wounds and promote healing. The water absorption and antifriction properties of dressings are important for regulating the moisture balance and reducing secondary damages during dressing changes. Herein, we developed a hyaluronic acid (HA)-based foam dressing prepared via the lyophilization of photocrosslinked HA hydrogels with high water absorption and antiadhesion properties. To fabricate the HA-based foam dressing (HA foam), the hydroxyl groups of the HA were modified with methacrylate groups, enabling rapid photocuring. The resulting photocured HA solution was freeze-dried to form a porous structure, enhancing its exudate absorption capacity. Compared with conventional biopolymer-based foam dressings, this HA foam exhibited superior water absorption and antifriction properties. To assess the wound-healing potential of HA foam, animal experiments involving SD rats were conducted. Full-thickness defects measuring 2 × 2 cm² were created on the skin of 36 rats, divided into four groups with 9 individuals each. The groups were treated with gauze, HA foam, CollaDerm^®, and CollaHeal^® Plus, respectively. The rats were closely monitored for a period of 24 days. In vivo testing demonstrated that the HA foam facilitated wound healing without causing inflammatory reactions and minimized secondary damages during dressing changes. This research presents a promising biocompatible foam wound dressing based on modified HA, which offers enhanced wound-healing capabilities and improved patient comfort and addresses the challenges associated with conventional dressings.

Complement component 3 (C3) deficiency has recently been known as a cause of constipation, without studies on the therapeutic efficacy. To evaluate the therapeutic agents against C3-deficiency-induced constipation, improvements in the constipation-related parameters and the associated molecular mechanisms were examined in FVB/N-C3^em1Hlee/Korl knockout (C3 KO) mice treated with uridine (Urd) and the aqueous extract of Liriope platyphylla L. (AEtLP) with laxative activity. The stool parameters and gastrointestinal (GI) transit were increased in Urd- and AEtLP-treated C3 KO mice compared with the vehicle (Veh)-treated C3 KO mice. Urd and AEtLP treatment improved the histological structure, junctional complexes of the intestinal epithelial barrier (IEB), mucin secretion ability, and water retention capacity. Also, an improvement in the composition of neuronal cells, the regulation of excitatory function mediated via the 5-hydroxytryptamine (5-HT) receptors and muscarinic acetylcholine receptors (mAChRs), and the regulation of the inhibitory function mediated via the neuronal nitric oxide synthase (nNOS) and inducible NOS (iNOS) were detected in the enteric nervous system (ENS) of Urd- and AEtLP-treated C3 KO mice. Therefore, the results of the present study suggest that C3-deficiency-induced constipation can improve with treatment with Urd and AEtLP via the regulation of the mucin secretion ability, water retention capacity, and ENS function.

Surface‐Templated Suprastructure Synthesis