Bio-Medical Materials and Engineering - Volume 34, issue 2

Authors: Li, Guangjun | Shen, Wen | Chu, Minghui | Mo, Guowei | Yao, Liqin | Xu, Weidong

Article Type: Research Article

Abstract: BACKGROUND: Calcium phosphate cements (CPCs) are biocompatible materials that have been evaluated as scaffolds in bone tissue engineering. At present, the stem cell density of inoculation on CPC scaffold varies. OBJECTIVE: The aim of this study is to analyze the effect of seeding densities on cell growth and osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs) on a calcium phosphate cements (CPCs) scaffold. METHODS: BMMSCs derived from minipigs were seeded onto a CPC scaffold at three densities [1 million/mL (1M), 5 million/mL (5M) and 25 million/mL 25M)], and cultured for osteogenic induction for 1, 4 and 8 …days. RESULTS: Well adhered and extended BMMSCs on the CPC scaffold showed significantly different proliferation rates within each seeding density group at different time points (P < 0.05). The number of live cells per unit area in 1M, 5M and 25M increased by 3.5, 3.9 and 2.5 folds respectively. The expression of ALP peaked at 4 days post inoculation with the fold-change being 2.6 and 2.8 times higher in 5M and 25M respectively as compared to 1M. The expression levels of OC, Coll-1 and Runx-2 peaked at 8 days post inoculation. CONCLUSIONS: An optimal seeding density may be more conducive for cell proliferation, differentiation, and extracellular matrix synthesis on scaffolds. We suggest the optimal seeding density should be 5 million/mL. Show more

Keywords: Bone marrow mesenchymal stem cells, calcium phosphate cement, seeding density, osteogenic differentiation

DOI: 10.3233/BME-221394

Citation: Bio-Medical Materials and Engineering, vol. 34, no. 2, pp. 111-121, 2023

Authors: Tanifuji, Osamu | Mochizuki, Tomoharu | Koga, Yoshio | Tanabe, Yuji | Kawashima, Hiroyuki

Article Type: Research Article

Abstract: BACKGROUND: Closed-wedge high tibial osteotomy (CWHTO) with a fibular osteotomy (FO) causes medial joint space widening in the knee. However, the effect of FO on the joint space width remains unclear. OBJECTIVE: This study aimed to examine the effect of FO on the knee in HTO. METHODS: A compression load test was performed on two amputated human limbs under four conditions: (1) normal (without any osteotomy), (2) open-wedge HTO (OWHTO), (3) OWHTO with FO, and (4) CWHTO. The contact area of the femoral and tibial cartilages and the medial and lateral joint space widths in each …condition were evaluated using a motion capture system with computed tomography (CT) and magnetic resonance imaging (MRI) data. RESULTS: The contact area increased on the lateral side after OWHTO, which increased more on the lateral side with a concomitant decrease on the medial side in both subjects when FO was added to OWHTO. An increase in the medial joint space width and a decrease on the lateral side were seen in both OWHTO with FO and CWHTO. CONCLUSIONS: The contact area and joint space widths are affected by the FO, and the effect is more pronounced than the way of HTO (OWHTO or CWHTO). Show more

Keywords: Knee, high tibial osteotomy, tibia, fibular osteotomy

DOI: 10.3233/BME-221395

Citation: Bio-Medical Materials and Engineering, vol. 34, no. 2, pp. 123-131, 2023

Authors: Turkay, Ece Yilmazkasapoglu | Kargul, Betul | Aydinoglu, Aysu Karakas | Yoruc, Afife Binnaz Hazar

Article Type: Research Article

Abstract: BACKGROUND: In the preventive treatment protocol, providing remineralization of the tissue in demineralized dentin caries is an important step. OBJECTIVE: In this in vitro study, the effectiveness of remineralization agents in natural caries-affected dentin (NCAD) were investigated. METHODS: Forty caries slices were prepared from permanent molar dentin with International Caries Detection and Assessment System (ICDAS 2) (Code 3). The interventions with 8 days pH cycling were as follows: Deionized water (DW); 5% Sodium Fluoride (5% NaF) Varnish; Casein Phosphopeptide-Amorphous Calcium Fluoride Phosphate (CPP-ACFP); Calcium Glyserophosphate (CaGP) + Magnesium (Mg) + Xylitol. DIAGNOdent (Laser Fluorescence, LF), Surface Microhardness (SMH), and …X-ray Fluorescence (XRF) Spectroscopy measurements were calculated before and after pH cycling. RESULTS: LF values decreased between 5% NaF, CCP-ACFP and CaGP. NCAD treated with 5% NaF, CaGP and CCP-ACFP exhibited statistically higher hardness compared to the control group. After 5% NaF application, SMH values were significantly higher than the others. There was no statistically significant difference between baseline and after pH cycling hardness of the control group. After cycling, XRF showed that Ca and P concentrations were increased in all groups. CONCLUSION: The application of agents used in the study could be recommended and promoted as a treatment option of caries dentin for conventional management of caries. Show more

Keywords: Calcium glycerophosphate, casein phosphopeptide-amorphous calcium phosphate, fluoride, natural caries-affected dentin (NCAD), pH cycling, surface microhardness

DOI: 10.3233/BME-221396

Citation: Bio-Medical Materials and Engineering, vol. 34, no. 2, pp. 133-142, 2023

Authors: Assani, Kaivon D. | Nosoudi, Nasim | Ramirez-Vick, Jaime E. | Singh, Surinder P.

Article Type: Research Article

Abstract: BACKGROUND: Modulation of macrophage polarization is required for effective tissue repair and regenerative therapies. Therapeutic modulation of macrophages from an inflammatory M1 to a fibrotic M2 phenotype could help in diseases, such as chronic wounds, which are stalled in a prolonged and heightened inflammatory stage within the wound healing process. OBJECTIVE: This study evaluates the efficiency of a pullulan/gelatin nanofiber scaffold loaded with retinoic acid (RA) and adipose-derived mesenchymal stem cells (ASCs) to modulate M1 to M2 anti-inflammatory transition. METHODS: Scaffolds were fabricated by electrospinning, and crosslinked using ethylene glycol diglycidyl ether (EGDE). Exposure of RA …and/or ASCs to cultured macrophages have been shown to promote M1 to M2 transition. Pullulan was chosen as a scaffold material due to its ability to quench reactive oxygen species, key signaling molecules that play an important role in the progression of inflammation, as well as for its excellent mechanical properties. Gelatin was chosen as an additional scaffold component due to the presence of cell-binding motifs and its biocompatibility. Scaffold compositions examined were 75:25 and 50:50, pullulan:gelatin. The scaffolds were crosslinked in 1:70 and 1:50 EGDE:EtOH. The scaffold composition was determined via FTIR. For the present study, the 75:25 pullulan:gelatin crosslinked with 1:70 EGDE:EtOH, forming nanofibers 328 ± 47.9 nm (mean ± SD) in diameter, was chosen as the scaffold composition due to its lower degradation and release rate, which allows a sustained delivery of RA. RESULTS: The scaffold composition degraded to approximately 80% after 14 days, with approximately 38% of the drug released after 7 days. THP-1 monocytic cells were induced into a M1 macrophage phenotype through stimulation with lipopolysaccharide (LPS) and gamma interferon (IFN-γ). These M1 macrophages were the exposed to scaffolds loaded with RA and ASCs, to induce differentiation to an M2 phenotype. CONCLUSION: Gene expression quantitation by qPCR showed a reduction of M1 biomarkers, tumor necrosis factor alpha (TNFα) and interleukin 1β (IL1β), and an increase of M2 biomarker CCL22 after 2 days of exposure, suggesting successful M1 to M2 transition. Show more

Keywords: Macrophage polarity, retinoic acid, mesenchymal stem cells, electrospinning, pullulan, gelatin

DOI: 10.3233/BME-221410

Citation: Bio-Medical Materials and Engineering, vol. 34, no. 2, pp. 143-157, 2023

Authors: Hayashi-Sakai, Sachiko | Kobayashi, Taichi | Hayashi, Takafumi | Shimomura-Kuroki, Junko | Sakai, Jun | Sakamoto, Makoto

Article Type: Research Article

Abstract: BACKGROUND: Suprahyoid muscles behavior during the tongue lifting movement has not yet been elucidated. OBJECTIVE: The purpose of this study was to investigate the potential of elastography imaging to examine developmental oral dysfunction in children and oral hypofunction in older adults using sonography. METHODS: Tongue pressure was measured using a manometer with a probe. The tongue pressure was measured with simultaneously scanning the geniohyoid muscle (GHM) and the anterior belly of the digastric muscle (DGM) using sonographic elastography. Sagittal images of the GHM and coronal images of the DGM were used for the strain ratio measurement. …The strain ratio of the muscles was measured three times for each subject with the tongue pressure values of 0–30 kPa. RESULTS: The strain ratio of the GHM were higher than those of the DGM at tongue pressure of 10, 20 and 30 kPa. The strain ratio of the GHM increased as the tongue pressure increased in all participants. In contrast, the strain ratio of the DGM tended to slowly decrease as tongue pressure increased in female participants. CONCLUSION: Sonographic elastography is useful for visual and quantitative evaluation of elastic properties in suprahyoid muscles during tongue lifting movements. Show more

Keywords: Suprahyoid muscles, tongue pressure, elasticity, sonographic elastography, strain ratio

DOI: 10.3233/BME-221414

Citation: Bio-Medical Materials and Engineering, vol. 34, no. 2, pp. 159-168, 2023

Authors: Zhang, Ying | Wang, Haijian | Kumazawa, Takashi | Ju, Dongying

Article Type: Research Article

Abstract: BACKGROUND: The effect of casting parameters on the microstructure and corrosion resistance of Mg alloys is still limited, especially in clinical animal experiments. OBJECTIVE: We prepared a new magnesium rare earth alloy (Mg-Re, where Re is Ce or La) by vertical two-roll casting and Mg-A by further rolling. The microstructure characteristics, degradation behavior, and bone reaction of the two alloys were studied. METHOD: Ti, Mg-Re, and Mg-A alloy plates were implanted in a rat femur model, and their degradation behavior was observed 48 weeks later. RESULTS: In vivo experiments showed no significant changes around …the femur in the Ti group, excluding external factors that may cause bone remodeling and lead to new bone formation. Mg-A induces more new bone formation than Mg-Re, which meets the necessary conditions to prevent pathological fracture. The specimen staining and sectioning showed that the liver and heart of rats implanted with magnesium alloys had no pathological changes and the cell structure was normal, similar to that of rats without a magnesium alloy. CONCLUSION: Mg-A alloy has good healing potential as a biodegradable implant material. Show more

Keywords: Mg-Re sheet, in vivo, amorphous, degradable, bone response

DOI: 10.3233/BME-221415

Citation: Bio-Medical Materials and Engineering, vol. 34, no. 2, pp. 169-181, 2023

Authors: Aytemiz, Derya G. | Kambe, Yusuke | Hirata, Mitsunobu | Nishi, Hirohito | Kameda, Tsunenori

Article Type: Research Article

Abstract: BACKGROUND: Collagen production in fibroblasts is important for skin tissue repair. Cell-adhesive Arg-Gly-Asp (RGD) peptides immobilized on scaffolds stimulate fibroblast collagen production, but RGD peptides in solution exhibit opposite effects. Transgenic silkworm technology enables the design of fusion positions for RGD peptides in silk fibroin molecules. The effect of RGD-fused silk fibroin in solution on fibroblast cell activity remains unclear. OBJECTIVE: To clarify the effects of RGD peptides fused to silk fibroin heavy (H)-chain or light (L)-chain on fibroblast proliferation and collagen production when RGD-fused silk fibroin proteins were added to the culture medium. METHODS: Silk …fibers with RGD-fused H-chains (H-RGD) or L-chains (L-RGD) were degummed, dissolved, and dialyzed to prepare H-RGD or L-RGD aqueous solutions, respectively. These solutions were added to the fibroblast medium, and their proliferation and collagen production were quantified. RESULTS: Both L- and H-RGD stimulated fibroblast proliferation at a similar level, even in a solution format, but L-RGD promoted fibroblast collagen production significantly, indicating the synergistic effect of the native H-chain and RGD-fused L-chain. CONCLUSION: RGD-fused silk fibroin in solution stimulated fibroblast proliferation and collagen production, depending on the fusion position of the peptides. Show more

Keywords: Silk fibroin, solution format, collagen production, RGD, transgenic silkworm

DOI: 10.3233/BME-221430

Citation: Bio-Medical Materials and Engineering, vol. 34, no. 2, pp. 183-193, 2023