A fracture-targeted supramolecular senolytic delivery platform was designed to clear early and accelerate fracture healing.
Evidence
This preclinical platform experiment synthesized AspSAC4A to bind exposed hydroxyapatite, co-deliver dasatinib and quercetin, and release them under hypoxic fracture-site conditions.
Caveat
The abstract does not specify the experimental model, sample size, comparator, or whether the healing benefits translate beyond the tested system.
Simplified
Current clinical management of fractures relies largely on surgical intervention and systemic pharmacotherapy, both of which are frequently associated with side effects and largely neglect early microenvironmental abnormalities. Precise elimination of at the early stage may offer a more efficient means of restoring microenvironmental homeostasis and resetting regenerative dynamics. To this end, we designed and synthesized a multifunctional , AspSAC4A, based on combination of host-guest recognition and self-assembly to simultaneously address three fundamental challenges in selectively eliminating senescent cells at the fracture site: inadequate targeting, insufficient responsiveness, and poor coordination of multi-drug delivery. The platform consists of an azocalix [4]arene modified with a deca-aspartate (Asp) peptide for selective binding to newly exposed hydroxyapatite at fracture sites, enabling active localization. Simultaneously, Dasatinib and Quercetin are co-loaded in a controlled ratio, and triggered for rapid release through the hypoxia-responsive mechanism of the azo groups, achieving microenvironment-specific "source-clearing" therapy. This strategy significantly alleviates inflammation, enhances osteogenesis and accelerates fracture healing. These results highlight the crucial role of selectively targeting senescent cells in the early phase of fracture and offer an innovative therapeutic approach that improves treatment efficiency and prognosis. Overall, this study aims to establish a fracture-site-activated senolytic delivery strategy that integrates fracture targeting, hypoxia-triggered release, and combination therapy, thereby enabling precise early-stage anti-senescence intervention to accelerate fracture healing. 10 10
Key numbers
significantly higher callus volume
Increase in callus volume
Compared to controls, DQ@AspSAC4A treatment resulted in larger callus formation.
14 days
Peak senescent cell accumulation
peaked at day 14 post-fracture, indicating a critical time for treatment.
Full Text
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Declarations. Ethics approval and consent to participate: The experimental protocol was reviewed and approved by the Ethics Committee of the Institute of Radiation Medicine, Chinese Academy of Medical Sciences (Approval No. IRM/2-IACUC-2406-007). We confirm that any aspect of the work covered in this manuscript that has involved experimental animals has been conducted with the ethical approval of all relevant bodies and that such approvals are acknowledged within the manuscript. Consent for publication: All authors agree to be published. Competing interests: The authors declare no competing interests.
