This study proposes a simple yet versatile microfluidic strategy for fabricating monodisperse alginate hydrogel microspheres using a symmetric flow-focusing device. The system integrates three key innovations: (1) Cost-effective mold fabrication: A paper-based positive master replaces conventional SU-8 photoresist, significantly simplifying device prototyping; (2) Surfactant-free droplet generation: Alginate hydrogel droplets are formed at the first flow-focusing junction without requiring interfacial stabilizers; (3) In situ solidification with coalescence suppression: Acetic acid-infused corn oil is introduced at the adjacent junction, simultaneously triggering ionic crosslinking of alginate via pH reduction while preventing droplet aggregation. Notably, the hydrogel microspheres can be efficiently harvested through oscillatory aqueous phase separation, removing post-fabrication washing steps (typically 6-8 cycles for surfactant and oil removal). This integrated approach demonstrates exceptional advantages in fabrication simplicity, process scalability, and operational robustness for high-throughput hydrogel microsphere production.

Stanniocalcin‑1 (STC‑1) is a multifunctional glycoprotein, yet its role in mitigating intestinal epithelial oxidative injury remains elusive. This study investigated the cytoprotective effects and underlying molecular mechanisms of STC‑1 in porcine intestinal epithelial cells (IPEC‑J2) subjected to tert‑butyl hydroperoxide (TBHP)‑induced oxidative stress. IPEC‑J2 cells were transfected with pcDNA3.1/STC‑1 prior to the TBHP challenge. STC‑1 overexpression markedly rescued IPEC‑J2 cells from TBHP‑induced cytotoxicity and apoptosis, as demonstrated by AO/PI dual-staining and a restored Bax/Bcl‑2 ratio. Concurrently, STC‑1 dramatically suppressed intracellular reactive oxygen species and mitochondrial superoxide accumulation while preserving the mitochondrial membrane potential. These physiological improvements were accompanied by enhanced total antioxidant capacity and upregulated activities of key antioxidant enzymes. Mechanistically, mRFP‑GFP‑LC3 reporter assays revealed STC‑1 enhanced autophagic processing and promoted Pink1/Parkin-mediated mitophagy to clear dysfunctional mitochondria. Furthermore, STC‑1 enhanced the AMPK–Nrf2/Sirt1 signaling axis, leading to Keap1 downregulation and the subsequent transcription of mitochondrial biogenesis markers (FoxO1, PGC‑1α, and TFAM) under stress conditions. Taken together, these findings demonstrate that STC‑1 safeguards porcine intestinal epithelial cells against oxidative injury by orchestrating a cooperative defense network that involves ROS scavenging, mitochondrial homeostasis, and antioxidant defense amplification via AMPK–Nrf2/Sirt1 pathway, presenting a potential therapeutic target for preventing stress-associated intestinal disorders in piglets.