Bienzyme-Engineered Fibrous Membranes: A Mitochondrial-Targeted Strategy to Reverse Bone Loss in Osteoporotic Models

Abstract

The rejuvenation of bone tissue remains a formidable challenge for osteoporosis (OP) patients who suffer severe bone degeneration or structural deterioration. To reverse the bone loss associated with OP, a dual-enzyme cascade system (PCF@EA) was engineered as a biomimetic engine to regulate bone metabolism imbalance. The bienzyme-driven system was constructed by integrating functionalized polymeric composite fibers with two mineralization-promoting hydrolases: recombinant human ectonucleotide pyrophosphatase/phosphodiesterase 1 (rhENPP1) and recombinant human alkaline phosphatase (rhALP). The bienzyme-driven engine efficaciously navigates mitochondria-activated mineralization through an autophagic process, thereby promoting osteogenic differentiation, increasing intracellular inorganic phosphate (Pi), and facilitating calcium influx. Concurrently, metabolic regulation mediated by the bienzyme-driven engine involves the PI3K–Akt pathway, tricarboxylic acid (TCA) cycle and glycerophosphate metabolism, significantly down-regulating the mineralization inhibitor pyrophosphate (PPi) while accelerating the formation of phosphate-related metabolites. Moreover, the enzyme-loaded substrates inhibited bone resorption by reducing expression of osteoclast activity markers, including Trap and Cath-K. This bienzymatic cascade strategy has demonstrated efficacy in restoring bone homeostasis in osteoporotic rats, significantly improving defect maturation and catalyzing the recovery of bone mineral density from severe loss back to baseline levels. The unique features of the bienzyme-driven engine provide a promising approach for the therapeutic treatment of degenerative skeletal diseases.

Keywords

Bienzyme-driven engine / Functionalized fibers / Mitophagy-activated mineralization / Osteoporosis / Maintaining bone homeostasis

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Funding

National Natural Science Foundation of China(32171338)

Sichuan International Science and Technology Innovation Cooperation Project(2024YFHZ0308)

Major Science and Technology Projects in Yunnan Province(202302AA310038)

RIGHTS & PERMISSIONS

Donghua University, Shanghai, China