Carbon fiber/polyetheretherketone (CF/PEEK) has been widely used in the field of bone repair. However, its bio-inert nature results in poor osseointegration, which significantly limits its long-term stability and bone repair efficacy in clinical applications. Here, a manganese-doped nano-hydroxyapatite (Mn/nHA) coating was constructed on the surface of CF/PEEK using a liquid-phase self-assembly strategy of inorganic nanoparticles. The experimental results demonstrated that both Mn/nHA and nHA coatings significantly improved the surface roughness and hydrophilicity of CF/PEEK. Further in vitro studies revealed that after co-culturing with rat mesenchymal stem cells (BMSCs) for 7 d, the relative cell viability of the Mn/nHA- and nHA-coated materials reached as high as 180% and 159%, respectively, indicating a pronounced pro-proliferative effect. Additionally, alizarin red staining and reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that both coatings enhanced cell mineralization and osteogenic differentiation on the material surface, with the Mn/nHA coating exhibiting a stronger promoting effect.

Nano-calcium phosphate (nCaP) has potential applications in nanomedicine fields such as drug delivery, bioimaging, antibacterial treatment, and bone formation promotion. However, its distribution and metabolic patterns within the body are not yet fully understood and require further in-depth research. This study employs a rare earth europium ion fluorescence labeling method and uses tumor-bearing mice as a model to investigate the distribution and metabolism of two sizes of nCaP (nanodots NDs: (2.53±0.63) nm; nanoparticles NPs: (107.76±25.37) nm×(17.66±1.63) nm) in the liver, spleen, lung, kidney, and tumor tissue. The results showed that after tail vein injection of 200 μL with a mass concentration of 1.5 mg/mL nCaP into tumor-bearing nude rats for 4 h, CaP NPs were primarily distributed in the liver and spleen, accounting for 65.70% and 29.32%, respectively, with 3.83% in the lung, while only 0.84% and 0.32% in the kidney and tumor. This suggests that larger CaP NPs are more easily captured by phagocytes within the reticuloendothelial system (RES). In contrast, compared to CaP NPs, accumulation of CaP NDs in the liver, spleen, and lung decreased significantly by 89.40%, 87.00%, and 88.89%, respectively, while their accumulation in the kidney and tumor increased by 3.67 and 3.06 times. This indicates that smaller particle size facilitates CaP NDs in glomerular filtration for urinary excretion and enhances their tumor-targeting capability. The clearance rates (CLz) of CaP NDs in the liver, spleen, and lung were 6.60, 4.14, and 2.40 times higher than that of CaP NPs, respectively, and 42.29% in the kidney. This indicates that reduced size of CaP NDs facilitates rapid metabolism by phagocytes in the liver, spleen, and lung but also results in reabsorption in the renal tubules. In tumor, the CLz of CaP NDs decreased by 91.9%, much smaller than that of CaP NPs, suggesting that the smaller CaP NDs exhibit significantly enhanced tumor targeting and retention capability. In the meantime, a physiologically based pharmacokinetic (PBPK) model incorporating particle size factors was preliminarily established for tumor-bearing mice to simulate the distribution of nano-calcium phosphate. The model's predictive fit (R²) for CaP NDs and CaP NPs in tumor sites reached 0.925 and 0.827, respectively. This study provides promising support for understanding in vivo distribution and metabolic patterns of nCaP and applying potential in medicine.

Inorganic non-metallic biomaterial is one of main types of biomaterials, which is widely used in biomedical fields such as tissue repair, tumor therapy, and drug delivery., making an important contribution to national life and health. Research on inorganic non-metallic biomaterials in China is flourishing, but their production and application are still in the stage of overcoming difficulties. To realize the high-quality development of China's inorganic non-metallic biomaterials and improve their hard power to protect national life and health, this paper analyzes hotspots and difficult problems in research and application of China's inorganic non-metallic biomaterials by means of strategic study. Based on current development opportunities and challenges, some suggestions are proposed for the development of inorganic non-metallic biomaterials, such as material design for unique performance, research on materiobiology, exploration of new principles and mechanisms mediated by materials, customization by intelligent personalization, design through big data screening and artificial intelligence, and standardization based evaluation/regulation. This aims to provide guidance for development of inorganic non-metallic biomedical products and push forward scientific research while accumulating talent resources.

Inorganic nanoparticles have demonstrated significant applications in biomedicine field, whose biomedical functions and physicochemical properties are greatly influenced by their size and morphology. However, it still remains challenging to achieve high batch-to-batch reproducibility in the synthesis of inorganic nanoparticles with traditional batch synthesis methods. Meanwhile, microfluidic technology offers an advanced strategy that provides high controllability and repeatability for the synthesis of inorganic nanoparticles. Additionally, it facilitates rapid mass and heat transfer, while offering the advantages of small reaction volumes and low energy consumption, rendering it an ideal approach for the synthesis of inorganic nano-biomaterials. This article reviews the research and application progress of microfluidic technology in preparation of inorganic nano-biomaterials. Firstly, flow regimes and principles of mixing in the microfluidic devices are introduced. Subsequently, structural features and fluid mixing efficiency of five widely studied and applied microfluidic devices are presented. Importantly, applications of these microfluidic devices in synthesis and surface modification of inorganic nanoparticles are comprehensively summarized. Finally, this article briefly outlines challenges and potential opportunities for future developments in microfluidic-based synthesis and application of inorganic nano-biomaterials.

Amorphous calcium carbonate (ACC) plays a crucial role in biomineralization which crystallization process has attracted significant attention. Magnesium ions (Mg²⁺) can effectively regulate the crystallization of ACC, but the mechanism by which it controls the transformation of ACC into monohydrocalcite (MHC, CaCO₃·H₂O) is not well understood. In this study, Mg²⁺ was used as an additive, and the transformation process from ACC to MHC was investigated in situ using an automatic potentiometric titration system. It was found that Mg²⁺ can enhance the stability of ACC and inhibit the formation of calcite and vaterite. During the transformation of ACC to MHC, partial dissolution firstly occurred, and the molar ratio of Mg/Ca in the solution increased with the consumption of Ca²⁺. Mg²⁺ further adsorbed onto the surface of ACC particles, inhibiting surface dissolution of ACC and promoting internal dissolution of ACC, resulting in the formation of hollow structures rich in Mg²⁺ and smaller-sized nanoparticles. Subsequently, MHC crystallized and grew through particle aggregation. These results elucidate the mechanism by which Mg²⁺ regulates the transformation of ACC into MHC through a non-classical crystallization pathway, enhancing an understanding of the biomineralization mechanism from ACC precursor.

Bioceramics have attracted extensive attention for bone defect repair due to their excellent bioactivity and degradability. However, challenges remain in matching the rate between bioceramic degradation and new bone formation, necessitating a deeper understanding of their degradation properties. In this study, density functional theory (DFT) calculations was employed to explore the structural and electronic characteristics of silicate bioceramics. These findings reveal a linear correlation between the maximum isosurface value of the valence band maximum (VBM_Fmax) and the degradability of silicate bioceramics. This correlation was subsequently validated through degradation experiments. Furthermore, the investigation on phosphate bioceramics demonstrates the potential of this descriptor in predicting the degradability of a broader range of bioceramics. This discovery offers valuable insights into the degradation mechanism of bioceramics and holds promise for accelerating the design and development of bioceramics with controllable degradation.

Hydroxyapatite (HAP), as a common bone repair material, still faces the risk of bacterial infection in the treatment of infectious bone defects, whose limited osteogenic properties also hinders its further application. This study used a coprecipitation method to prepare the manganese doped hydroxyapatite nanorod (MnHAP), which exhibited excellent cell biocompatibility, high antibacterial efficiency and osteogenic properties. Antibacterial experiments showed that the inhibition rates of MnHAP10(n(Mn)/n(Ca+Mn)=10%)) against Escherichia coli and Staphylococcus aureus can reach 77.85% and 75.92%, respectively. Moreover, the antibacterial efficiency of MnHAP10 against Escherichia coli can be further enhanced (97.63%) under 808 nm near-infrared light irradiation. Cell proliferation and related osteogenic gene experiments display that MnHAP is beneficial for the proliferation and differentiation of osteoblasts, which improves protein adsorption capacity, stimulates osteogenic activity, and promotes the expression of related osteogenic genes, demonstrating its good biocompatibility. Therefore, MnHAP nanorods are expected to provide a new approach in the treatment of infectious bone defects.

The question of what qualities excellent medical bioceramics must possess to ensure satisfactory prognosis for bone healing and reconstruction remains a topic of great interest in both clinical and biomaterial sciences. Our team has been dedicated to researching medical bioceramics since the 1990s, involving basic scientific research, applied translational research, and clinical trials. Consequently, we have amassed a wealth of research and implementation experience. In this article, we aim to explore the subject of “Functional Bioadaptability in Medical Bioceramics”, specifically focusing on calcium phosphate-based materials. We summarized how to effectively combine bioadaptability with design and manufacturing of medical bioceramics in the background of orthopedic clinical application, with the following aspects of structural adaptability, degradative adaptability, mechanical adaptability, and application adaptability. Hopefully, some suggestions put forward can ultimately provide valuable insights and recommendations for the design, production, supervision, and application of the upcoming medical bioceramics.