A steroid‑induced osteonecrosis model established using an organ‑on‑a‑chip platform

Abstract

Bone microvascular endothelial cells (BMECs) constitute the central part of the femoral head's intramural microenvironment network and have an essential role in the development of steroid-induced osteonecrosis of the femoral head. Recently, the rapid development of microfluidic technology has led to innovations in the fields of chemistry, medicine and life sciences. It is now possible to use microfluidics organ-on-a-chip techniques to assess osteonecrosis. In the present study, BMECs were cultured on a microfluidic organ-on-a-chip platform to explore the pathogenesis of femoral-head necrosis. The aim of the present study was to explore the effects of different interventions on BMECs and study the pathogenesis of steroid-induced osteonecrosis through a microfluidic organ-on-a-chip platform. Methods including SU-8 lithography were used to produce a microfluidic organ-on-a-chip and human umbilical vein endothelial cells (HUVECs) were used to test whether it was possible to culture cells on the chip. Subsequently, a set of methods were applied for the isolation, purification, culture and identification of BMECs. Hydroxyapatite (HA) was used for co-culture, dexamethasone was used at different concentrations as an intervention in the cells and icariin was used for protection. BMECs were isolated and cultured from the femoral head obtained following total hip arthroplasty and were then inoculated into the microfluidic organ-on-a-chip for further treatment. In part I of the experiment, HUVECs and BMECs both successfully survived on the chip and a comparison of the growth and morphology was performed. HA and BMECs were then co-cultured for comparison with the control group. The cell growth was observed by confocal microscopy after 24 h. In part II, the effects of different concentrations of glucocorticoid (0.4 or 0.6 mg/ml dexamethasone) and the protection of icariin were evaluated. The morphology of BMECs and the cleaved caspase-3/7 content were observed by immunofluorescence staining and confocal microscopy after 24 h. In the microfluidic organ-on-a-chip, the response of the cells was able to be accurately observed. In part I, at the same concentration of injected cells, BMECs exhibited improved viability compared with HUVECs (P<0.05). In addition, it was indicated that HA was not only able to promote the germination and growth of BMECs but also improve the survival of the cells (P<0.05). In part II, it was identified that dexamethasone was able to induce BMECs to produce cleaved caspase 3/7; the caspase 3/7 content was significantly higher than that in the blank control group (P<0.05) and a dose correlation was observed. Icariin was able to inhibit this process and protect the microvascular structure of BMECs. The content of cleaved caspase 3/7 in the icariin-protected group was significantly lower than that in the group without icariin (P<0.05). It was concluded that BMECs are more likely to survive than HUVECs and HA promoted the growth of BMECs on the microfluidic organ-on-a-chip platform. Glucocorticoid caused dama...

Autocrine Activity of Extracellular Vesicles Induced by Icariin and Its Effectiveness in Glucocorticoid-Induced Injury of Bone Microvascular Endothelial Cells

“…The BMECs were isolated following the methods described in the previous article [ 17 ]. The normal cancellous bone from the femoral head was processed into bone particles and washed with PBS thrice.…”

Polarization Behavior of Bone Macrophage as Well as Associated Osteoimmunity in Glucocorticoid-Induced Osteonecrosis of the Femoral Head

“…Bone microvessels are monolayer structures essential for bone formation and metabolism, and direct contact with ingredient in the blood. 98 In our former study, it could be found that glucocorticoid intervention could induce apoptosis of the BMECs and enhance eleven cytokines in the released extracellular vesicles ( Figure 5 ). 98 , 99 Among them, S100A8 (Fold change = 56.23) is an atypical inflammatory cytokine that is most markedly elevated, which could also promote the M1 polarization of macrophage and the chronic inflammatory processes by activating the TLR4/NF-κB signal pathway according to published article.…”

“… 98 In our former study, it could be found that glucocorticoid intervention could induce apoptosis of the BMECs and enhance eleven cytokines in the released extracellular vesicles ( Figure 5 ). 98 , 99 Among them, S100A8 (Fold change = 56.23) is an atypical inflammatory cytokine that is most markedly elevated, which could also promote the M1 polarization of macrophage and the chronic inflammatory processes by activating the TLR4/NF-κB signal pathway according to published article. 100 The glucocorticoid-induced injury of bone microvascular endothelial vessels and subsequently enhanced level of BMECs-derived cytokines may act as a prerequisite for the macrophage-induced chronic inflammation in GIONFH.…”

Establishment of the multi-component bone-on-a-chip: to explore therapeutic potential of DNA aptamers on endothelial cells

“…We also added HA to the multicomponent compositions to simulate the proportion of mineral substances in bone tissues. Although previous reports indicated that the two-component culture of HA and BMECs could enhance the cell growth (Li et al, 2021), the effects on cell growth and angiogenesis status in multi-component culture pattern still remains unclear. Our design of three parallel culture patterns was to make sure that each group must be cultivated under the same circumstance.…”