A variable mineralization time and solution concentration intervene in the microstructure of biomimetic mineralized collagen and potential osteogenic microenvironment

Xiujie Zhu; Haotian Bai; He Liu; Zhonghan Wang; Yao Wang; Jiaxin Zhang; Jiaqi Liu; Hui Wang; Jincheng Wang

doi:10.3389/fbioe.2023.1267912

A variable mineralization time and solution concentration intervene in the microstructure of biomimetic mineralized collagen and potential osteogenic microenvironment

Front Bioeng Biotechnol. 2023 Dec 6:11:1267912. doi: 10.3389/fbioe.2023.1267912. eCollection 2023.

Authors

Xiujie Zhu^{1

2}, Haotian Bai^{1

2}, He Liu^{1

2}, Zhonghan Wang^{1

2}, Yao Wang¹, Jiaxin Zhang^{1

2}, Jiaqi Liu^{1

2}, Hui Wang^{1

2}, Jincheng Wang^{1

2}

Affiliations

¹ Department of Orthopedics, The Second Hospital of Jilin University, Changchun, China.
² Orthopaedic Research Institute of Jilin Province, Changchun, China.

Abstract

The absence of a conducive bone formation microenvironment between fractured ends poses a significant challenge in repairing large bone defects. A promising solution is to construct a bone formation microenvironment that mimics natural bone tissue. Biomimetic mineralized collagen possesses a chemical composition and microstructure highly similar to the natural bone matrix, making it an ideal biomimetic bone substitute material. The microstructure of biomimetic mineralized collagen is influenced by various factors, and its biomineralization and microstructure, in turn, affect its physicochemical properties and biological activity. We aimed to utilize mineralization time and solution concentration as variables and employed the polymer-induced liquid precursor strategy to fabricate mineralized collagen with diverse microstructures, to shed light on how mineralization parameters impact the material microstructure and physicochemical properties. We also investigated the influence of microstructure and physicochemical properties on cell biocompatibility and the bone-forming microenvironment. Through comprehensive characterization, we examined the physical and chemical properties of I-EMC under various mineralization conditions and assessed the in vitro and in vivo biocompatibility and osteogenic performance. By investigating the relationship between mineralization parameters, material physicochemical properties, and osteogenic performance, we revealed how microstructures influence cellular behaviors like biocompatibility and osteogenic microenvironment. Encouragingly, mineralization solutions with varying concentrations, stabilized by polyacrylic acid, successfully produced intrafibrillar and extrafibrillar mineralized collagen. Compared to non-mineralized collagen, all mineralized samples demonstrated improved bone-forming performance. Notably, samples prepared with a 1× mineralization solution exhibited relatively smooth surfaces with even mineralization. Extending the mineralization time enhanced the degree of mineralization and osteogenic performance. Conversely, samples prepared with a 2× mineralization solution had rough surfaces with large calcium phosphate particles, indicating non-uniform mineralization. Overall, our research advances the potential for commercial production of mineralized collagen protein products, characterized by dual biomimetic properties, and their application in treating various types of bone defects.

Keywords: microstructure; mineralization solution concentration; mineralization time; mineralized collagen; osteogenic microenvironment; physicochemical properties.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was financially supported by the National Natural Science Foundation of China (Grant Nos. 82001971, 82102358, U23A20523, and 82202698); Scientific Development Program of Jilin Province (Grant Nos. 20200403088SF, 20220204117YY, YDZJ202201ZYTS086, 20200404202YY, and 20200802008GH); Program of Jilin Provincial Health Department (Grant No. 2020SC2T064 and 2020SC2T065); Project of “Medical + X” Interdisciplinary Innovation Team of Norman Bethune Health Science Center of Jilin University (Grant No. 2022JBGS06); China Postdoctoral Science Foundation (Grant No. 2021M701384); Bethune Plan of Jilin University (Grant No. 2022B27, 2022B03).