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Background and Objectives@#Osteoblasts are derived from bone marrow mesenchymal stem cells (BMMSCs) and playimportant role in bone remodeling. While our previous studies have investigated the cell subtypes and heterogeneity in osteoblasts and BMMSCs separately, cell-to-cell communications between osteoblasts and BMMSCs in vivo in humans have not been characterized. The aim of this study was to investigate the cellular communication between human primary osteoblasts and bone marrow mesenchymal stem cells. @*Methods@#and Results: To investigate the cell-to-cell communications between osteoblasts and BMMSCs and identifynew cell subtypes, we performed a systematic integration analysis with our single-cell RNA sequencing (scRNA-seq) transcriptomes data from BMMSCs and osteoblasts. We successfully identified a novel preosteoblasts subtype which highly expressed ATF3, CCL2, CXCL2 and IRF1. Biological functional annotations of the transcriptomes suggested that the novel preosteoblasts subtype may inhibit osteoblasts differentiation, maintain cells to a less differentiated status and recruit osteoclasts. Ligand-receptor interaction analysis showed strong interaction between mature osteoblasts and BMMSCs. Meanwhile, we found FZD1 was highly expressed in BMMSCs of osteogenic differentiation direction. WIF1 and SFRP4, which were highly expressed in mature osteoblasts were reported to inhibit osteogenic differentiation. We speculated that WIF1 and sFRP4 expressed in mature osteoblasts inhibited the binding of FZD1 to Wnt ligand in BMMSCs, thereby further inhibiting osteogenic differentiation of BMMSCs. @*Conclusions@#Our study provided a more systematic and comprehensive understanding of the heterogeneity of osteogenic cells. At the single cell level, this study provided insights into the cell-to-cell communications between BMMSCs and osteoblasts and mature osteoblasts may mediate negative feedback regulation of osteogenesis process.
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OBJECTIVE: Taking aspirin as a model drug, the feasibility of the controlled release of aspirin tablets was discussed, which was based on the individual demand of 3D printing technology. METHODS: The experiment selected 10 000 mPa·s hydroxypropyl methyl cellulose (HPMC10000) and polyacrylic acid (PAA) as a hydrophilic matrix sustained-release layer; hydroxypropyl methyl cellulose 100 mPa·s (HPMC100) as a quick release layer binder, sodium carboxymethyl starch (CMS-Na) and sodium carboxymethyl starch (SSG) as a quick release layer disintegrating agent, the use of 3D printer to print the slow release of aspirin tablets. Select 100 mg·mL-1 and polyvinylpyrrolidone (PVPK30) as a quick release layer binder, crosslinking sodium carboxymethyl cellulose (CC-Na) as a quick release layer disintegrating agent, hydroxypropyl methyl cellulose (HPMC100) as the matrix material release layer, with the traditional press pressing speed of aspirin sustained-release tablet, as contrast agents. The physical and chemical properties of tablets produced in two different modes of production (film weight difference, hardness and thickness) and release profile were investigated. RESULTS: The physical and chemical properties of the two tablets are all in the Pharmacopoeia. Comparison of two kinds of drug release curve showed that the ASA-HPMC (14%, ω) and the press release curve of double layer tablets printing film is similar, and the release rate is higher than the tablet (6% ω. ASA-HPMC double layer tablets), ASA-HPMC (8%, ω) and ASA-HPMC (10%, ω) printing film final release amount increased with hydrophilic matrix HPMC. CONCLUSION: 3D printers print different shapes of tablets with different release profiles, in which the release of the package is higher than the other tablets.