Abaloparatide

Abaloparatide is an engineered 34-amino-acid analog of the parathyroid hormone-related protein (PTHrP) that is identical to the native protein over the first 21 residues but differs by eight strategic substitutions at residues 22–34 and an α-aminoisobutyric acid substitution at residue 29 to augment helical stability. The changes in Abaloparatide bias the ligand toward the G-protein-coupled (RG) conformation of the PTH-1 receptor and lead to a transient cAMP pulse. In turn, this results in high production of osteoblast-derived anabolic mediators (IGF-1, osteocalcin), but markedly less RANKL and M-CSF expression, rapid bone formation with limited resorption, and little or no hypercalcemia.
In post-menopausal women the 80 µg daily subcutaneous dose of abaloparatide increased lumbar-spine, femoral-neck and total-hip BMD at a fast rate, reduced new vertebral and non-vertebral fracture risk by about one-half, and was seen to provide protection earlier. Biopsy and imaging data demonstrated thicker trabeculae and higher trabecular bone scores. Switching to alendronate after 18 months of Abaloparatide treatment preserved density gains and continued to reduce fracture rates, providing a cost-effective and well-tolerated anabolic sequence for the long-term management of osteoporosis.

Fig. 1 Mechanism of action of Abaloparatide. (Bhattacharyya S.; et al. 2019)

Tan B et al. developed biodegradable bifunctional calcium phosphorus nanoflowers (ABL@NFs) loaded with abaloparatide to achieve spatiotemporal management of post-extraction alveolar bone regeneration. The synthesized NFs featured a porous hierarchical structure with high drug encapsulation efficiency and excellent biocompatibility. The system initially releases ABL to recruit stem cells, followed by sustained release of Ca²⁺ and PO₄³⁻ ions for in situ interface mineralization, creating an osteogenic "biomineralized environment." The ABL@NFs successfully restored morphologically and functionally active alveolar bone without interfering with orthodontic tooth movement, demonstrating potential as an artificial "bone powder" for hard tissue regeneration applications.

Fig. 2 Abaloparatide-loaded biodegradable calcium phosphorus nanoflowers. (Tan B.; et al. 2025)