Biomimetic inorganic-organic hybrid nanoparticles from magnesium-substituted amorphous calcium phosphate clusters and polyacrylic acid molecules

Na Li, Wei Cui, Peifang Cong, Jie Tang, Yong Guan, Caihao Huang, Yunen Liu, Chengzhong Yu, Rui Yang, Xing Zhang

Research output: Contribution to journalArticleResearchpeer-review

24 Citations (Scopus)

Abstract

Amorphous calcium phosphate (ACP) has been widely found during bone and tooth biomineralization, but the meta-stability and labile nature limit further biomedical applications. The present study found that the chelation of polyacrylic acid (PAA) molecules with Ca2+ ions in Mg-ACP clusters (~2.1 ± 0.5 nm) using a biomineralization strategy produced inorganic-organic Mg-ACP/PAA hybrid nanoparticles with better thermal stability. Mg-ACP/PAA hybrid nanoparticles (~24.0 ± 4.8 nm) were pH-responsive and could be efficiently digested under weak acidic conditions (pH 5.0–5.5). The internalization of assembled Mg-ACP/PAA nanoparticles by MC3T3-E1 cells occurred through endocytosis, indicated by laser scanning confocal microscopy and cryo-soft X-ray tomography. Our results showed that cellular lipid membranes remained intact without pore formation after Mg-ACP/PAA particle penetration. The assembled Mg-ACP/PAA particles could be digested in cell lysosomes within 24 h under weak acidic conditions, thereby indicating the potential to efficiently deliver encapsulated functional molecules. Both the in vitro and in vivo results preliminarily demonstrated good biosafety of the inorganic-organic Mg-ACP/PAA hybrid nanoparticles, which may have potential for biomedical applications.

Original languageEnglish
Pages (from-to)2303-2314
Number of pages12
JournalBioactive Materials
Volume6
Issue number8
DOIs
Publication statusPublished - Aug 2021
Externally publishedYes

Keywords

  • ACP clusters
  • Cellular degradation
  • Cryo-soft X-ray tomography
  • Inorganic-organic hybrid
  • pH responsive

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