Carbohydrate analyses are often challenging due to the structural complexity of these molecules, as well as the lack of suitable analytical tools for distinguishing the vast number of possible isomers. The coupled technique, ion mobility-mass spectrometry (IM-MS), has been in use for two decades for the analysis of complex biomolecules, and in recent years it has emerged as a powerful technique for the analysis of carbohydrates. For carbohydrates, most studies have focused on the separation and characterization of isomers in biological samples. IM-MS is capable of separating isomeric ions by drift time, and further characterizing them by mass analysis. Applications of IM-MS in carbohydrate analysis are extremely useful and important for understanding many biological mechanisms and for the determination of disease states, although efforts are still needed for higher sensitivity and resolution.
Bone, a mineralized tissue, continuously undergoes remodeling. It is a process that engages the mineralization and demineralization of the bone matrix, orchestrated by the interactions among cells and cell-secreted biomolecules under the bone ionic microenvironment (BIE). The osteoinductive properties of the demineralized organic bone matrix and many biological factors have been well-investigated. However, the impact of the bone ionic environment on cell differentiation and osteogenesis remains largely unknown. In this study, we extracted and isolated inorganic bone components (bone-derived monetite, BM) using a low-temperature method and, for the first time, investigated whether the BIE could actively affect cell differentiation and regulate osteoimmune reactions. It was evidenced that the BIE could foster the osteogenesis of human bone marrow stromal cells (hBMSCs) and promote hBMSCs mineralization without using osteogenic inductive agents. Interestingly, it was noted that BIE resulted in intracellular mineralization, evidenced by intracellular accumulation of carbonate hydroxyapatite similar to that oberved in osteoblasts cultured in osteoinductive media. Additionally, BIE was found to enhance osteogenesis by generating a favorable osteoimmune environment. In a rat calvarial bone defect model, the osteogenic capacity of BIE was evaluated using a collagen type I-impregnated BM (Col-BM) composite. It showed that Col-BM significantly promoted new bone formation in the critical-size bone defect areas. Taken together, this is the first study that investigated the influence of the BIE on osteogenesis, osteoimmunology, and in situ bone tissue engineering. The innate osteoinductive potential of inorganic bone components, both in vitro and in vivo, not only expands the understanding of the BIE on osteogenesis but also benefits future biomaterials engineering for bone tissue regeneration.
Bone is capable of adjusting size, shape, and quality to maintain its strength, toughness, and stiffness and to meet different needs of the body through continuous remodeling. The balance of bone homeostasis is orchestrated by interactions among different types of cells (mainly osteoblasts and osteoclasts), extracellular matrix, the surrounding biological milieus, and waste products from cell metabolisms. Inorganic ions liberated into the localized microenvironment during bone matrix degradation not only form apatite crystals as components or enter blood circulation to meet other bodily needs but also alter cellular activities as molecular modulators. The osteoinductive potential of inorganic motifs of bone has been gradually understood since the last century. Still, few have considered the naturally generated ionic microenvironment’s biological roles in bone remodeling. It is believed that a better understanding of the naturally balanced ionic microenvironment during bone remodeling can facilitate future biomaterial design for bone tissue engineering in terms of the modulatory roles of the ionic environment in the regenerative process.
6 January 2023 in ACS Applied Materials & Interfaces
The identification, uptake, and clearance of nanoparticles (NPs) by phagocytes are critical in NP-based therapeutics. The cell membrane coating technique has recently emerged as an ideal surface modification approach to help NP bypass phagocytosis. CD47, a regulatory protein for phagocytosis, is a cell surface glycoprotein expressed on all cell types, including platelets. Herein, we enclosed bioactive glass (BG) with a platelet membrane to bestow BG with unique cell surface functions for immune evasion and immunomodulation. Compared with the uncoated particles, platelet membrane-coated BG shows reduced cellular uptake and can generate an immune environment favorable for osteogenesis. This is evidenced by the triggering of robust osteogenic differentiation in bone mesenchymal stromal cells, suggesting the synergistic effect of platelet membrane and BG in bone regeneration. These collectively indicate that cell membrane coating is a promising approach to enhance the therapeutic efficacy of biomaterials and thus provide new insight into biomaterial-mediated bone regeneration.
Biomineralization is a process that leads to the formation of hierarchically arranged structures in mineralized tissues, such as bone and teeth. Extensive research has been conducted on the crystals in bones and teeth, with the aim of understanding the underlying mechanisms of the mineralization process. Pathological/ectopic mineralization, such as kidney stones, calcific tendinitis, and skeletal fluorosis, shares some similar features but different mechanisms to physiological mineralization. A better understanding will provide new perspectives for treating pathological/ectopic mineralization-related diseases. This review provides an overview of the mechanisms of the crystallization and growth of crystals in physiological and pathological conditions from a chemistry perspective. By linking the microstructures and functions of crystals formed in both conditions, potential approaches are proposed to treat pathological/ectopic mineralization-related diseases.