Citrate‐Based Tannin‐Bridged Bone Composites for Lumbar Fusion. (30th April 2020)

• Record Type: Journal Article
• Authors: Guo, Jinshan; Tian, Xinggui; Xie, Denghui; Rahn, Kevin; Gerhard, Ethan; Kuzma, Michelle Laurel; Zhou, Dongfang; Dong, Cheng; Bai, Xiaochun; Lu, Zhihui; Yang, Jian
• Is Part Of: Advanced functional materials. Volume 30:Number 27(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-04-30
• Subjects: biomimetics -- bone regeneration -- citrate‐based biodegradable polymers -- composite materials -- tannin‐mediated adhesion; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202002438
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Conventional bone composites consistently fail to mimic the chemical composition and integrated organic/inorganic structure of natural bone, lacking sufficient mechanics as well as inherent osteoconductivity and osteoinductivity. Through a facile surface coating process, the strong adhesive, tannic acid (TA), is adhered to the surface of the natural bone component, hydroxyapatite (HA), with and without the immobilization of in situ formed silver nanoparticles. Residual functional groups available on the immobilized TA substituents are subsequently covalently linked to the citrate‐based biodegradable polymer, poly(octamethylene citrate) (POC), effectively bridging the organic and inorganic phases. Due to the synergistic effects of the tannin and citrate components, the obtained citrate‐based tannin‐bridged bone composites (CTBCs) exhibit vastly improved compression strengths up to 323.0 ± 21.3 MPa compared to 229.9 ± 15.6 MPa for POC‐HA, and possess tunable degradation profiles, enhanced biomineralization performance, favorable biocompatibility, increased cell adhesion and proliferation, as well as considerable antimicrobial activity. In vivo study of porous CTBCs using a lumbar fusion model further confirms CTBCs' osteoconductivity and osteoinductivity, promoting bone regeneration. CTBCs possess great potential for bone regeneration applications while the immobilized TA additionally preserves surface bioconjugation sites to further tailor the bioactivity of CTBCs. Abstract : Tannin is introduced into citrate‐based bone composites to better mimic bone by strongly adhering to inorganic particles and chemically reacting with organic polymers. The tannin moiety uniquely bridges the inorganic and organic phases, conferring citrate‐based tannin‐bridged bone composites with greatly increased compression strengths, significant antimicrobial properties, enhanced biomineralization, and improved cell adhesion while preserving bioconjugation sites for further functionalization.