Investigation of angiogenesis by in vivo multiphoton microscopy during bone formation in murine calvarial critical bone defect repaired by genetically modified 3D-PLGA/nHAp SCAFFOLD

Abstract Background: Diabetes mellitus (DM) is considered to be an important factor for bone degeneration disorders such as bone defect nonunion, which is characterized by physical disability and tremendous economy cost to families and society. Exosomal miRNAs of BMSCs have been reported to participate in osteoblastogenesis and modulating bone formation. However, their impacts on the development of bone degeneration in DM are not yet known. The role of miRNAs in BMSCs exosomes on regulating hyperglycemia bone degeneration was investigated in the present study. Results: The osteogenic potential in bone defect repair of exosomes derived from diabetes mellitus BMSCs derived exosomes (DM-Exos) were revealed to be lower than that in normal BMSCs derived exosomes (N-Exos) in vitro and in vivo. Here, we demonstrate that miR-140-3p level was significantly altered in exosomes derived from BMSCs, ADSCs and serum from DM rats. In in vitro experiments, upregulated miR-140-3p exosomes promoted DM BMSCs differentiation into osteoblasts. The effects were exerted by miR-140-3p targeting plxnb1, plexin B1 is the receptor of semaphoring 4D(Sema4D) that inhibited osteocytes differentiation, thereby promoting bone formation. In DM rats with bone defect, miR-140-3p upregulated exosomes were transplanted into injured bone and accelerated bone regeneration. Besides, miR-140-3p in the exosomes was transferred into BMSCs and osteoblasts and promoted bone regeneration by targeting the plexin B1/RohA/ROCK signaling pathway. Conclusions: Normal-Exos and miR-140-3p overexpressed-Exos accelerated diabetic wound healing by promoting the osteoblastogenesis function of BMSCs through inhibition plexin B1 expression which is the receptor of Sema4D and the plexin B1/RhoA/ROCK pathway compared with diabetes mellitus-Exos. This offers a new insight and a new therapy for treating diabetic bone unhealing.

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Recapitulating bone development through engineered mesenchymal condensations and mechanical cues for tissue regeneration

Science Translational Medicine ◽

10.1126/scitranslmed.aav7756 ◽

2019 ◽

Vol 11 (495) ◽

pp. eaav7756 ◽

Cited By ~ 24

Author(s):

Anna M. McDermott ◽

Samuel Herberg ◽

Devon E. Mason ◽

Joseph M. Collins ◽

Hope B. Pearson ◽

...

Keyword(s):

Tissue Engineering ◽

Bone Formation ◽

Mechanical Loading ◽

Bone Defect ◽

Bone Development ◽

Limb Bud ◽

Mechanical Forces ◽

Endochondral Bone ◽

Large Bone

Large bone defects cannot form a callus and exhibit high complication rates even with the best treatment strategies available. Tissue engineering approaches often use scaffolds designed to match the properties of mature bone. However, natural fracture healing is most efficient when it recapitulates development, forming bone via a cartilage intermediate (endochondral ossification). Because mechanical forces are critical for proper endochondral bone development and fracture repair, we hypothesized that recapitulating developmental mechanical forces would be essential for large bone defect regeneration in rats. Here, we engineered mesenchymal condensations that mimic the cellular organization and lineage progression of the early limb bud in response to local transforming growth factor–β1 presentation from incorporated gelatin microspheres. We then controlled mechanical loading in vivo by dynamically tuning fixator compliance. Mechanical loading enhanced mesenchymal condensation–induced endochondral bone formation in vivo, restoring functional bone properties when load initiation was delayed to week 4 after defect formation. Live cell transplantation produced zonal human cartilage and primary spongiosa mimetic of the native growth plate, whereas condensation devitalization before transplantation abrogated bone formation. Mechanical loading induced regeneration comparable to high-dose bone morphogenetic protein-2 delivery, but without heterotopic bone formation and with order-of-magnitude greater mechanosensitivity. In vitro, mechanical loading promoted chondrogenesis and up-regulated pericellular matrix deposition and angiogenic gene expression. In vivo, mechanical loading regulated cartilage formation and neovascular invasion, dependent on load timing. This study establishes mechanical cues as key regulators of endochondral bone defect regeneration and provides a paradigm for recapitulating developmental programs for tissue engineering.

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Human Fat-Derived Mesenchymal Stem Cells Xenogenically Implanted in a Rat Model Show Enhanced New Bone Formation in Maxillary Alveolar Tooth Defects

Stem Cells International ◽

10.1155/2020/8142938 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14

Author(s):

Andrew Wofford ◽

Austin Bow ◽

Steven Newby ◽

Seth Brooks ◽

Rachel Rodriguez ◽

...

Keyword(s):

Bone Formation ◽

Osteogenic Differentiation ◽

Bone Defect ◽

Bone Healing ◽

Alveolar Bone ◽

Cell Attachment ◽

Maxillofacial Surgery ◽

Human Mscs ◽

Defect Site

Background. Due to restorative concerns, bone regenerative therapies have garnered much attention in the field of human oral/maxillofacial surgery. Current treatments using autologous and allogenic bone grafts suffer from inherent challenges, hence the ideal bone replacement therapy is yet to be found. Establishing a model by which MSCs can be placed in a clinically acceptable bone defect to promote bone healing will prove valuable to oral/maxillofacial surgeons. Methods. Human adipose tissue-derived MSCs were seeded onto Gelfoam® and their viability, proliferation, and osteogenic differentiation was evaluated in vitro. Subsequently, the construct was implanted in a rat maxillary alveolar bone defect to assess in vivo bone healing and regeneration. Results. Human MSCs were adhered, proliferated, and uniformly distributed, and underwent osteogenic differentiation on Gelfoam®, comparable with the tissue culture surface. Data confirmed that Gelfoam® could be used as a scaffold for cell attachment and a delivery vehicle to implant MSCs in vivo. Histomorphometric analyses of bones harvested from rats treated with hMSCs showed statistically significant increase in collagen/early bone formation, with cells positive for osteogenic and angiogenic markers in the defect site. This pattern was visible as early as 4 weeks post treatment. Conclusions. Xenogenically implanted human MSCs have the potential to heal an alveolar tooth defect in rats. Gelfoam®, a commonly used clinical biomaterial, can serve as a scaffold to deliver and maintain MSCs to the defect site. Translating this strategy to preclinical animal models provides hope for bone tissue engineering.

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Bone Regeneration at Cortical Bone Defect with Unidirectional Porous Hydroxyapatite In Vivo

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.396-398.11 ◽

2008 ◽

Vol 396-398 ◽

pp. 11-14 ◽

Cited By ~ 6

Author(s):

Masashi Iwasashi ◽

Masataka Sakane ◽

Yasushi Suetsugu ◽

Naoyuki Ochiai

Keyword(s):

Bone Formation ◽

Cortical Bone ◽

Bone Defect ◽

Proximal Tibia ◽

New Bone Formation ◽

Porous Hydroxyapatite ◽

Japanese White Rabbit ◽

Great Possibility ◽

Porous Area

Unidirectional porous hydroxyapatite (UDPHAp) was developed which has microstructure in that cross sectionally oval pores 100 ~ 300µm in diameter penetrate through the material, and that is suitable for osteogenesis and angiogenesis.The porosity of the UDPHAp was 75 % and the compression strength was 14 MPa. A cortical bone defect was made at proximal tibia of Japanese white rabbit, and a trapezoidal prisms shaped UDPHAp was implanted. By histlogical evaluation, 2 weeks after implantation, new bone and new capillary was observed inside UDPHAp. Twelve weeks after implantation, new bone formation was observed in 41.6 % of the porous area. The results of this study suggest a great possibility of utilizing it in actual clinical setting as a bone substitution.

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