Treatment of early avascular necrosis of femoral head by small intestinal submucosal matrix with peripheral blood stem cells

Stem cell therapy for osteonecrosis of femoral head: Opportunities and challenges

Osteonecrosis of the femoral head (ONFH) is a progressive disease with a complex etiology and unclear pathogenesis, resulting in severe hip pain and dysfunction mainly observed in young patients. Although total hip arthroplasty (THA) is the most effective treatment for patients with ONFH in the terminal stage, the results of THA in young patients or active populations are often not favorable, with some complications related to the prosthesis. With the development of biotechnology, an increasing number of studies pay attention to use of stem cells for the treatment of ONFH. Stem cells are characterized by the ability to self-renew and differentiate into multiple cell types, including differentiation into osteoblasts and endothelial cells to mediate bone repair and angiogenesis. Furthermore, stem cells can offer growth factors to promote blood supply in the necrotic regions by paracrine effects. Therefore, stem cell therapy has become one of the hip-preserving alternatives for ONFH. This review summarized the current trends in stem cell therapy for ONFH, from clinical applications to related basic research, and showed that an increasing number of studies have confirmed the effectiveness of stem cell therapy in ONFH. However, many unsolved problems and challenges in practical applications of stem cell therapy still exist, such as patient selection, standardized procedures, safety assessment, and the fate of transplanted cells in the body. Additional studies are required to find ideal cell sources, appropriate transplantation methods, and the optimal number of cells for transplantation.

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Diversities in repair processes present a challenge in the targeted treatment of ONFH.

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Osteogenesis and angiogenesis are the primary mechanisms of MSCs treatment in ONFH.

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Systematic safety assessment and cell tracing are necessary for stem cell therapy.

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Optimal numbers and methods of cell transplantation need to be further confirmed.

Multiscale Stem Cell Technologies for Osteonecrosis of the Femoral Head

The last couple of decades have seen brilliant progress in stem cell therapies, including native, genetically modified, and engineered stem cells, for osteonecrosis of the femoral head (ONFH). In vitro studies evaluate the effect of endogenous or exogenous factor or gene regulation on osteogenic phenotype maintenance and/or differentiation towards osteogenic lineage. The preclinical and clinical outcomes accelerate the clinical translation. Bone marrow mesenchymal stem cells and adipose-derived stem cells have demonstrated better effects in the treatment of femoral head necrosis. Various materials have been used widely in the ONFH treatment in both preclinical and clinical trials. In a word, in vivo and multiscale efforts are expected to overcome obstacles in the approaches for treating ONFH and provide clinical relevance and commercial strategies in the future. Therefore, we will discuss the above aspects in this paper and present our opinions.

Critical assessment of the efficiency of CD34 and CD133 antibodies for enrichment of rabbit hematopoietic stem cells

Rabbits have many hereditary diseases common to humans and are therefore a valuable model for regenerative disease and hematopoietic stem cell (HSC) therapies. Currently, there is no substantial data on the isolation and/or enrichment of rabbit HSCs. This study was initiated to evaluate the efficiency of the commercially available anti-CD34 and anti-CD133 antibodies for the detection and potential enrichment of rabbit HSCs from peripheral blood. PBMCs from rabbit and human blood were labelled with different clones of anti-human CD34 monoclonal antibodies (AC136, 581, and 8G12) and rabbit polyclonal CD34 antibody (pCD34) and anti-human CD133 monoclonal antibodies (AC133 and 293C3). Flow cytometry showed a higher percentage of rabbit CD34⁺ cells labelled by AC136 in comparison to the clone 581 and pCD34 (P < 0.01). A higher percentage of rabbit CD133⁺ cells were also detected by 293C3 compared to the AC133 clone (P < 0.01). Therefore, AC136 clone was used for the indirect immunomagnetic enrichment of rabbit CD34⁺ cells using magnetic-activated cell sorting (MACS). The enrichment of the rabbit CD34⁺ cells after sorting was low in comparison to human samples (2.4% vs. 39.6%). PCR analyses confirmed the efficient enrichment of human CD34⁺ cells and the low expression of CD34 mRNA in rabbit positive fraction. In conclusion, the tested antibodies might be suitable for detection, but not for sorting the rabbit CD34⁺ HSCs and new specific anti-rabbit CD34 antibodies are needed for efficient enrichment of rabbit HSCs. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018 © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:1278-1289, 2018.

Effect of Multilaminate Small Intestinal Submucosa as a Barrier Membrane on Bone Formation in a Rabbit Mandible Defect Model

A barrier membrane (BM) is essential for guided bone regeneration (GBR) procedures. Absorbable BMs based on collagen have been widely applied clinically due to their excellent biocompatibility. The extracellular matrix (ECM) provides certain advantages that can compensate for the rapid degradation and insufficient mechanical strength of pure collagen membrane due to the porous scaffold structure. Recently, small intestinal submucosa (SIS), one of the most widely used ECM materials, has drawn much attention in bone tissue engineering. In this study, we adopted multilaminate SIS (mSIS) as a BM and evaluated its in vivo and in vitro properties. mSIS exhibited a multilaminate structure with a smooth upper surface and a significantly coarser bottom layer according to microscopic observation. Tensile strength was 13.10 ± 2.56 MPa. In in vivo experiments, we selected a rabbit mandibular defect model and subcutaneous implantation to compare osteogenesis and biodegradation properties with one of the most commonly used commercial collagen membranes. mSIS was retained for up to 3 months and demonstrated longer biodegradation time than commercial collagen membrane. Quantification of bone regeneration revealed significant differences in each group. Micro-computed tomography (micro-CT) revealed that the quantity and maturity of bones in the mSIS group were significantly higher than those in the blank control group (P < 0.05) and were similar to those in a commercial collagen membrane group (P > 0.05) at 4 and 12 weeks after surgery. Hematoxylin and eosin staining revealed large amounts of mature lamellar bone at 12 weeks in mSIS and commercial collagen membrane groups. Therefore, we conclude that mSIS has potential as a future biocompatible BM in GBR procedures.

Dyslipidaemia for patients with low-energy femoral neck fractures after the treatment of cancellous screws: a retrospective study with a 3-year minimum follow-up

Background

Avascular necrosis of the femoral head (AVNFH) occurs infrequently following femoral neck fracture. The association between AVNFH and dyslipidaemia remains controversial. Although major risk factors for AVNFH have been proposed, most of them remain under discussion. Our purpose herein was to evaluate the association between dyslipidaemia and AVNFH following low-energy femoral neck fractures treated with cancellous screws in elderly patients in our tertiary care centre.

Methods

Four hundred and seventy-two consecutive patients (472 hips) with low-energy femoral neck fractures were identified and treated with cancellous screws from July 2007 to April 2013. Patients underwent evaluations preoperatively and each subsequent postoperative visit (months 1, 6, 12, 18, 24, 30, and 36). Clinical and radiographic evaluations were documented at each visit. The risk factors of AVNFH were assessed by multivariate binary logistic analysis.

Results

Follow-up was available for 277 patients, which included 135 patients diagnosed with AVNFH (AVNFH group) and 142 patients without AVNFH (control group). The median follow-up for patients alive at the time of analysis was 40 months (range, 37 to 46 months). The mean total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), and apolipoprotein B (Apo-B) values were considerably higher in the AVNFH group compared with those in the control group. The mean high density lipoprotein cholesterol (HDL-C) and apolipoprotein A1(Apo-A1) values were significantly lower in the AVNFH group compared with those in the control group. A multivariate logistic backward regression model showed that HDL-C and LDL-C were the only variables associated with the development of postoperative AVNFH in patients with a femoral neck fracture (Odds ratio[OR] 33.09, 95% Confidence Interval[CI]: 2.65–19.42, p < 0.001 and OR 45.94, 95% CI: 0.47–27.75, p < 0.001, respectively).

Conclusion

Our results suggest that both low HDL-C and high LDL-C have a tendency to result in the occurrence of AVNFH in elderly patients with low-energy femoral neck fractures treated with cancellous screws.

Cortisol inhibits mTOR signaling in avascular necrosis of the femoral head

BACKGROUND

ANFH is a major health problem, to which long lasting and definitive treatments are lacking. The aim of this study is to study RNA alterations attributed to cortisol-induced ANFH.

METHODS

Rat models were stratified into three groups: in vitro group (n = 20) for molecular biological assays, control group (n = 3), and ANFH group induced using lipopolysaccharide and dexamethasone (n = 3). Bone marrow-derived endothelial progenitor cells (BM-EPCs) were extracted from the rats. An RNA expression array was performed on BM-EPCs, and enriched genes were subject to pathway analysis. In vitro studies following findings of array results were also performed using the isolated BM-EPCs.

RESULTS

Significant alterations in mammalian target of rapamycin (mTOR) and HIF signaling pathways were identified in BM-EPCs of ANFH. By applying cortisol and dexamethasone to BM-EPCs, significant changes in mTOR and HIF elements were identified. The alteration of HIF pathways appeared to be downstream of mTOR signaling. Glucocorticoid receptor (GR) expression was related to glucocorticoid-dependent mRNA expression of mTOR/HIF genes. mTOR-dependent angiogenesis but not anabolism was the target of GR in ANFH. Inhibition of mTOR signaling also induced apoptosis of BM-EPCs via CHOP-dependent DR5 induction in response to GR stimulation.

CONCLUSION

Decreased mTOR signaling in response to GR stimulation leading to downregulated HIF pathway as well as increased apoptosis could be the pathophysiology.

Naringin inhibits vascular endothelial cell apoptosis via endoplasmic reticulum stress‑ and mitochondrial‑mediated pathways and promotes intraosseous angiogenesis in ovariectomized rats

In this study, to investigate the effects of naringin on vascular endothelial cell (VEC) function, proliferation, apoptosis, and angiogenesis, rat VECs were cultured in vitro and randomly divided into four groups: control, serum‑starved, low‑concentration naringin treatment, and high‑concentration naringin treatment. MTT assay was used to detect cell proliferation while Hoechst 33258 staining and flow cytometry were used to detect apoptosis. Changes in the expression of apoptosis‑associated proteins [GRP78, CHOP, caspase‑12, and cytochrome c (Cyt.c)] were detected using western blotting. JC‑1 staining was employed to detect changes in mitochondrial membrane potential. Intracellular caspase‑3, ‑8, and ‑9 activity was determined by spectrophotometry. ELISA was used to detect endothelin (ET), and a Griess assay was used to detect changes in the expression of nitric oxide (NO) in culture medium. The study further divided an ovariectomized (OVX) rat model of osteoporosis randomly into four groups: OVX, sham‑operated, low‑concentration naringin treatment (100 mg/kg), and high‑concentration naringin treatment (200 mg/kg). After 3 months of treatment, changes in serum ET and NO expression, bone mineral density (BMD), and microvessel density of the distal femur (using CD34 labeling of VECs) were determined. At each concentration, naringin promoted VEC proliferation in a time‑ and dose‑dependent manner. Naringin also significantly reduced serum starvation‑induced apoptosis in endothelial cells, inhibited the expression of GRP78, CHOP, caspase‑12, and Cyt.c proteins, and reduced mitochondrial membrane potential as well as reduced the activities of caspase‑3 and ‑9. Furthermore, naringin suppressed ET in vitro and in vivo while enhancing NO synthesis. Distal femoral microvascular density assessment showed that the naringin treatment groups had a significantly higher number of microvessels than the OVX group, and that microvascular density was positively correlated with BMD. In summary, naringin inhibits apoptosis in VECs by blocking the endoplasmic reticulum (ER) stress‑ and mitochondrial‑mediated pathways. Naringin also regulates endothelial cell function and promotes angiogenesis to exert its anti‑osteoporotic effect.

Combination treatment of biomechanical support and targeted intra-arterial infusion of peripheral blood stem cells mobilized by granulocyte-colony stimulating factor for the osteonecrosis of the femoral head: a randomized controlled clinical trial

The objective of this study was to determine the benefits of combination treatment with mechanical support and targeted intra-arterial infusion of peripheral blood stem cells (PBSCs) mobilized by granulocyte-colony stimulating factor (G-CSF) via the medial circumflex femoral artery on the progression of osteonecrosis of the femoral head (ONFH). Fifty-five patients (89 hips) with early and intermediate stage ONFH were recruited and randomly assigned to combination treatment or mechanical support treatment (control group). All hips received mechanical support treatment (porous tantalum rod implantation). Then, hips in the combination treatment group were performed targeted intra-arterial infusion of PBSCs. At each follow-up, Harris hip score (HHS) and Association Research Circulation Osseous (ARCO) classification were used to evaluate the symptoms and progression of osteonecrosis. Total hip arthroplasty (THA) was assessed as an endpoint at each follow-up. At 36 months, 9 of the 41 hips (21.95%) in the control group progressed to clinical failure and underwent THA whereas only 3 of the 48 hips (6.25%) in the combination treatment group required THA (p = 0.031). Kaplan-Meier survival analysis showed a significant difference in the survival time between the two groups (log-rank test; p = 0.025). Compared to the control group, combination treatment significantly improved the HHS at 36 months (p = 0.003). At the final follow-up examination, radiological progression was noted in 13 of 41 hips (31.71%) for the control group, but in only 4 of 48 hips (8.33%) for the combination treatment group (p = 0.005). The overall collapse rates were 15.15% (5/33 hips) and 8.11% (3/37 hips) in the control and combination treatment groups, respectively. Targeted intra-arterial infusion of PBSCs is capable of enhancing the efficacy of biomechanical support in the treatment of ONFH. This clinical trial confirmed that the combination treatment might be a safe and feasible choice for the treatment of early or intermediate stages of ONFH.

Construction of tissue-engineered bone using a bioreactor and platelet-rich plasma

The aim of the present study was to construct tissue-engineered bone using a bioreactor and platelet-rich plasma (PRP). Bone marrow mesenchymal stem cells (BMSCs) and β-tricalcium phosphate (β-TCP) were cultured in a perfusion bioreactor with PRP-containing medium for 21 days to form a BMSC-TCP composite. Rabbits were then implanted with the BMSC-TCP composite. The morphology of the implanted BMSC-TCP composite was observed three months after surgery by scanning electron microscopy and hematoxylin and eosin (H&E) staining. In addition, the expression of cluster of differentiation (CD)31 and von Willebrand factor (WF) in the implanted BMSC-TCP composite was detected using immunohistochemistry. Bone formation was determined by comprehensive testing Following culture in a perfusion bioreactor and PRP, the BMSCs adhered to the β-TCP scaffold and the secretion of extracellular matrix was observed. The spreading and proliferation of cells was found to be enhanced on the scaffold. Furthermore, the vascular endothelial cell markers CD31 and VEF, were positively expressed. Therefore, these results suggest that tissue-engineered bone may be constructed using a bioreactor and PRP. PRP, which contains multiple growth factors, may promote vascularization of tissue-engineered bone.

Stem cell therapy for the treatment of early stage avascular necrosis of the femoral head: a systematic review

Background

Avascular necrosis (AVN) of the femoral head (FH) is believed to be caused by a multitude of etiologic factors and is associated with significant morbidity in younger populations. Eventually, the disease progresses and results in FH collapse. Thus, a focus on early disease management aimed at joint preservation by preventing or delaying progression is key. The use of stem cells (SC) for the treatment of AVN of the FH has been proposed. We undertook a systematic review of the medical literature examining the use of SC for the treatment of early stage (precollapse) AVN of the FH, in both pre-clinical and clinical studies.

Methods

Data collected included: Pre-clinical studies – model of AVN, variety and dosage of SC, histologic and imaging analyses. Clinical studies – study design, classification and etiology of AVN, SC dosage and treatment protocol, incidence of disease progression, patient reported outcomes, volume of necrotic lesion and hip survivorship.

Results

In pre-clinical studies, the use of SC uniformly demonstrated improvements in osteogenesis and angiogenesis, yet source of implanted SC was variable. In clinical studies, groups treated with SC showed significant improvements in patient reported outcomes; however hip survivorship was not affected. Discrepancies regarding dose of SC, AVN etiology and disease severity were present.

Conclusions

Routine use of this treatment method will first require further research into dose and quality optimization as well as confirmed improvements in hip survivorship.

Small intestinal submucosa segments as matrix for tissue engineering: review

Tissue engineering (TE) is an emerging interdisciplinary field aiming at the restoration or improvement of impaired tissue function. A combination of cells, scaffold materials, engineering methods, and biochemical and physiological factors is employed to generate the desired tissue substitute. Scaffolds often play a pivotal role in the engineering process supporting a three-dimensional tissue formation. The ideal scaffold should mimic the native extracellular environment providing mechanical and biological properties to allow cell attachment, migration, and differentiation, as well as remodeling by the host organism. The scaffold should be nonimmunogenic and should ideally be resorbed by the host over time, leaving behind only the regenerated tissue. More than 40 years ago, a preparation of the small intestine was introduced for the replacement of vascular structures. Since then the small intestinal submucosa (SIS) has gained a lot of interest in TE and subsequent clinical applications, as this material exhibits key features of a highly supportive scaffold. This review will focus on the general properties of the SIS and its applications in therapeutical approaches as well as in generating tissue substitutes in vitro. Furthermore, the main problem of TE, which is the insufficient nourishment of cells within three-dimensional, artificial tissues exceeding certain dimensions is addressed. To solve this issue the implementation of another small intestine-derived preparation, the biological vascularized matrix (BioVaM), could be a feasible option. The BioVaM comprises in addition to SIS the arterial and venous mesenteric pedicles and exhibits thereby a perfusable vessel bed that is preserved after decellularization.