Autologous and allogeneic bone grafts are primarily used for bone tissue defects; however, they have limitations such as limited supply, donor site morbidity, and immune rejection risks. Therefore, substitute synthetic bone grafts are required.
Using low-temperature 3D printing combined with freeze-drying technology, a hierarchically porous PLGA/HA@SeNPs composite scaffold was fabricated by compositing poly(lactic-co-glycolic acid) (PLGA) with hyaluronic acid-modified selenium nanoparticles (HA@SeNPs), enabling sustained immunomodulation and osteogenic activity through its engineered microtopography and bioactive components.
In vitro evaluations confirmed that the unique microstructure and sustained selenium release from HA@SeNPs synergistically promoted macrophage polarization toward the M2 phenotype, accompanied by enhanced osteogenic differentiation as shown by upregulation of Runx2 and OCN and accelerated matrix mineralization. Implantation into a rat femoral critical-sized defect model resulted in substantially improved bone repair and architectural restoration.
These findings indicate that the intrinsic physicochemical properties of the PLGA/HA@SeNPs scaffold orchestrate a favorable osteo-immune environment, positioning it as a promising platform for bone regeneration.
Shengwen Cheng, Yuqiao Wang, Yu Zhai et al.· Burns & Trauma· 0 citations
Tissue regeneration is a central frontier in biomedicine, yet articular cartilage defect repair in osteoarthritis (OA) remains a formidable challenge. Although mesenchymal stem cell (MSC)-based therapies show great potential for cartilage regeneration, their clinical translation is hindered by sequential barriers: low cell retention, oxidative stress-induced apoptosis, and inefficient MSC homing to defect sites and subsequent integration. Herein, we fabricate chondrogenic niche hydrogel microspheres (Chonichspheres) via microfluidics. These HMs are composed of gelatin methacryloyl (GelMA)/aldehyde-hyaluronic acid methacrylate (AHAMA) composite matrices loaded with amino fullerenes (AF) and transforming growth factor-β3 (TGF-β3). Chonichspheres exert four synergistic functions: GelMA acts as a structural scaffold to promote MSC adhesion; AF exert sustained antioxidant effects to regulate redox homeostasis in MSCs and OA chondrocytes; AHAMA enables precise targeted homing and tissue integration; and TGF-β3 induces MSC chondrogenic differentiation. Validated by an HM-adapted custom microphysiological system (MPS) and in vivo experiments, Chonichspheres activate the integrin–PI3K–AKT–mTOR axis, protecting MSCs and facilitating chondrogenic differentiation under OA-mimicking dynamic culture conditions. By synergizing active covalent tissue integration with durable, non-sacrificial antioxidant defense, this programmatic platform provides a robust precision regenerative strategy for OA cartilage repair.
Jinping Chen, pengcheng xiao, Xingkuan Wang et al.· Bioactive Materials· 0 citations
