Osteopontin-loaded nanoarchaeosomes for enhanced osteogenesis and bone regeneration in osteoporotic zebrafish models.

Osteoporosis is a progressive bone disorder characterized by reduced bone density, structural deterioration, and impaired regeneration. Current pharmacological treatments, including bisphosphonates, hormone therapy, and monoclonal antibodies, often exhibit limited long-term efficacy and systemic side effects, underscoring the need for biocompatible and stable delivery systems that can sustain osteogenic signalling within compromised bone microenvironments. Here, we report the development of nanoarchaeosomes loaded with osteopontin (NAO) - a colloidally stable, lipid-based nanocarrier engineered to enhance osteogenesis and bone regeneration. NAO exhibited a uniform morphology with an average size of 56 ± 1.0 nm, high stability, and a drug-loading efficiency of 98 ± 1%. In vitro assays with MG63 osteoblasts revealed concentration-dependent increases in alkaline phosphatase (ALP) activity, confirming enhanced osteogenic differentiation. In vivo studies demonstrated high biocompatibility in zebrafish embryos, along with increased bone count, mineral density, and regenerative capacity in both fin-fracture and amputation models. Furthermore, zebrafish models of osteoporosis treated with NAO showed improved Ca : P ratios, enhanced mineralization, and upregulation of key osteogenic genes, indicating robust bone regeneration. Collectively, these findings establish osteopontin-loaded nanoarchaeosomes as an efficient nanoplatform capable of sustaining osteogenic signaling and accelerating bone repair, offering a therapeutic strategy to overcome the limitations of current osteoporosis treatment.