Aims

To assess the alterations in cell-specific DNA methylation associated with chondroitin sulphate response using peripheral blood collected from Kashin-Beck disease (KBD) patients before initiation of chondroitin sulphate treatment.

Aims

cAMP response element binding protein (CREB1) is involved in the progression of osteoarthritis (OA). However, available findings about the role of CREB1 in OA are inconsistent. 666-15 is a potent and selective CREB1 inhibitor, but its role in OA is unclear. This study aimed to investigate the precise role of CREB1 in OA, and whether 666-15 exerts an anti-OA effect.

For patients who took joint replacement, one of the complications, aseptic joint loosening, could cause a high risk of revision surgery. Studies have shown that MSCs have the ability of homing and differentiating, and also have highly effective immune regulation and anti-inflammatory effects. However, few studies had focused on the stem cells in preventing the occurrence and development of aseptic loosening. In this research, we aimed to clarify whether human umbilical cord mesenchymal stem cells could inhibited the aseptic joint loosening caused by wear particles.

A Cranial osteolysis mice model was established on mice to examine the effect of hUC-MSCs on the Titanium particles injection area through micro-CT. The amount of stem cells injected was 2 × 10 5 cells. One week later, the mouse Cranial were obtained for micro-CT scan, and then stained with HE analysis immunohistochemical analysis of TNF-α, CD68, CCL3 and Il-1β.

All mice were free of fever and other adverse reactions, and there was no death occurred. Titanium particles caused the osteolysis at the mice cranial, while local injection of hUC-MSCs did inhibit the cranial osteolysis, with a lower BV/TV and a higher porosity. Immunohistochemical results suggested that the expression of TNF-α, CD68, CCL3 and Il-1β in the cranial in Titanium particles mice increased significantly, but was significantly reduced in mice injected with hUC-MSCs. The inhibited CD68 expression indicated that the number of macrophage was lower, which might be a result of the inhibition of CCL3.

According to the studies above, HUC-MSCs treatment of mouse cranial osteolysis model can significantly reduce osteolysis, inhibit macrophage recruitment, alleviate inflammatory response, without causing adverse reactions. It may become a promising treatment of aseptic joint loosening.

Total joint replacement (TJR) was one of the most revolutionary breakthroughs in joint surgery. The majority studies had shown that most implants could last about 25 years, anyway, there is still variation in the longevity of implants. In US, for all the hip revisions from 2012 to 2017 in the United States, 12.0% of the patients were diagnosed as aseptic loosening. Variable studies have showed that any factor that could cause a systemic or partial bone loss, might be the risk of periprosthetic osteolysis and aseptic loosening.

Breast cancer is the most frequent malignancy in women, more than 2.1 million women were newly diagnosed with breast cancer, 626,679 women with breast cancer died in 2018. It's been reported that the mean incidence of THA was 0.29% for medicare population with breast cancer in USA, of which the incidence was 3.46% in Norwegian. However, the effects of breast cancer chemotherapy and hormonotherapy, such as aromatase inhibitors (AI), significantly increased the risk of osteoporosis, and had been proved to become a great threat to hip implants survival.

In this case, a 46-year-old female undertook chemotherapy and hormonotherapy of breast cancer 3 years after her primary THA, was diagnosed with aseptic loosening of the hip prosthesis. Her treatment was summarized and analyzed.

Breast cancer chemotherapy and hormonotherapy might be a threat to the stability of THA prosthesis. More attention should be paid when a THA paitent occurred with breast cancer. More studies about the effect of breast cancer treatments on skeleton are required.

Osteoarthritis (OA), the most prevalent chronic joint disease, represents a relevant social and economic burden worldwide. Human umbilical cord mesenchymal stem cells (HUCMSCs) have been used for injection into the joint cavity to treat OA. The aim of this article is to clarify whether Huc-MSCs derived exosomes could inhibit the progression of OA and the mechanism in this process.

A rabbit OA model was established by the transection of the anterior cruciate ligament. The effects of HUCMSCs or exosomes derived from HUCMSCs on repairing articular cartilage of knee osteoarthritis was examined by micro-CT. Immunohistochemical experiments were used to confirm the expression of relevant inflammatory molecules in OA. In vitro experiments, Transwell assay was used to assess the migration of macrophages induced by TNF-a.

Results showed that a large number of macrophages migrated in arthcular cavity in OA model in vivo, while local injection of HUCMSCs and exosomes did repair the articular cartilage. Immunohistochemical results suggested that the expression of CCL2 and CD68 in the OA rabbit model increased significantly, but was significantly reduced by HUCMSCs or exosomes. Transwell assay showed that both HUCMSCs and exosomes can effectively inhibit the migration of macrophage.

In conclusion, the exosomes derived by HUCMSCs might might rescue cartilage defects in rabbit through its anti-inflammatory effects through inhibiting CCL2.

Osteoarthritis (OA) is a common age-related degenerative joint disease, affecting 7% of the global population, more than 500 million people worldwide. Exosomes from mesenchymal stem cells (MSCs) showed promise for OA treatment, but the insufficient biological targeting weakens its efficacy and might bring side effects. Here, we report the chondrocyte-targeted exosomes synthesized via click chemistry as a novel treatment for OA.

Exosomes are isolated from human umbilical cord-derived MSCs (hUC-MSCs) using multistep ultracentrifugation process, and identified by electron microscope and nanoparticle tracking analysis (NTA). Chondrocyte affinity peptide (CAP) is conjugated on the surface of exosomes using click chemistry. For tracking, nontagged exosomes and CAP-exosomes are labeled by Dil, a fluorescent dye that highlights the lipid membrane of exosomes. To verify the effects of CAP-exosomes, nontagged exosomes and CAP-exosomes are added into the culture medium of interleukin (IL)-1β-induced chondrocytes. Immunofluorescence are used to test the expression of matrix metalloproteinase (MMP)-13.

CAP-exosomes, compared with nontagged exosomes, are more easily absorbed by chondrocytes. What's more, CAP-exosomes induced lower MMP-13 expression of chondrocytes when compared with nontagged exosomes (p<0.001).

CAP-exosomes show chondrocyte-targeting and exert better protective effect than nontagged exosomes on chondrocyte extracellular matrix. Histological and in vivo validation are now being conducted.

Introduction

The Center for Medicare and Medicaid Services (CMS) is faced with a challenge of decreasing the cost of care for total knee arthroplasty (TKA), but must make efforts to prevent patient selection bias in the process. Currently, no appropriate modifier codes exist for primary TKA based on case complexity. We sought to determine differences in perioperative parameters for patients with “complex” primary TKA with the hypothesis that they would require increased cost of care, prolonged care times, and have worse postoperative outcome metrics.

Introduction

Infection following total knee arthroplasty (TKA) is a catastrophic complication. In the United States, for chronic, first time infected TKA, the gold standard remains a 2-stage reimplantation (2SR) procedure, with reported success rates approaching 90%. However, there is a lack of consensus on the treatment of subsequent reinfections.

Objective

To identify risk factors for the presence of distal adding-on in Lenke 1A scoliosis and compare different treatment strategies.

Introduction

How translation of different parts of spine responds to selective thoracic fusion has not been well investigated. Furthermore, how posterior pedicle-screw-only constructs affect spontaneous lumbar curve correction (SLCC) remains unknown. In a retrospective study, we aimed to investigate the balance change after selective thoracic fusion in Lenke 1C type adolescent idiopathic scoliosis (AIS) treated with posterior pedicle-screw-only constructs.

Introduction

Distal adding-on is often accompanied by unsatisfactory clinical outcome and high risk of reoperation. However, very few studies have focused on distal adding-on and its attendant risk factors, and optimum treatment strategies remain controversial. In a retrospective study, we aimed to identify risk factors for the presence of distal adding-on in Lenke 1A scoliosis and to compare different treatment strategies.

Developing biomaterials for bone regeneration that are highly bioactive, resorbable and mechanically strong remains a challenge. Zreiqat's lab recently developed novel scaffolds through the controlled substitution of strontium (Sr) and zinc (Zn) into calcium silicate, to form Sr-Hardystonite and Hardystonite, respectively and investigated their in vivo biocompatibility and osteoconductivity

We synthesized 3D scaffolds of Sr-Hardystonite, Hardystonite and compared them to the clinically used tricalcium phosphate (micro-TCP) (6 × 6 × 6 mm) using a polyurethane foam template to produce a porous scaffold. The scaffolds were surgically implanted in the proximal tibial metaphysis of each tibia of Female Wistar rats. Animals were sacrificed at three weeks and six weeks post-implantation and bone formation and scaffold resorption were assessed by microcomputed tomography (micro-CT) histomorphometry and histology. Histological staining on undecalcified sections included Toluidine blue, tartrate-resistant acid phosphatase (TRAP) and alkaline phosphatase (ALP).

The bone formation rate and mineral apposition rate will be determined by analysing the extent and separation of fluorescent markers by fluorescent microscopy micro-CT results revealed higher resorbability of the developed scaffolds (Sr-Hardystonite and Hardystonite) which was more pronounced with the Sr-Hardystonite. Toluidine blue staining revealed that the developed ceramics were well tolerated with no signs of rejection, necrosis, or infection. At three weeks post implantation, apparent bone formation was evident both at the periphery and within the pores of the all the scaffolds tested. Bone filled in the pores of the Sr- Hardystonite and Hardystonite scaffolds and was in close contact with the ceramic. In contrast, the control scaffolds showed more limited bone ingrowth and a cellular layer separating the ceramic scaffolds from the bone. By six weeks the Hardystonite and Sr Hardystonite scaffolds were integrated with the bone with most pores filled with new bone. The control scaffold showed new bone formation in the plane of the cortical bone but little new bone where the scaffold entered the marrow space. Sr Hardystonite showed the greatest resorbability with replacement of the ceramic material by bone.

We have developed novel engineered scaffolds (Sr-Hardystonite) for bone tissue regeneration. The developed scaffolds resorbed faster than the clinically used micro- TCP with greater amount of bone formation replacing the resorbed scaffold.

Currently available calcium silicate based ceramics pseudowollostonite (CaSiO3) ceramics are regarded as a potential bioactive material for bone tissue regeneration due to their osseointegration properties. A drawback of CaSiO3 ceramics is that they possess high dissolution rate, leading to a high pH value in the surrounding environment thereby affecting the biological activity of bone cells. We hypothesize that chemical modification of CaSiO3 ceramics will improve their physical and biological properties. The coordinated activities of osteoblasts (OB) and osteoclasts (OC) are critical for proper bone remodelling. Moreover, growing evidence indicate that vascular endothelial cells are involved in bone development and remodelling.

Present study aims at Chemically modifying CaSiO3 by incorporating zinc (Zn) and titanium (Ti) into their structure to develop novel materials Hardystonite (HT, Ca2ZnSi2O7) and Sphene (CaTiSiO5), respectively and to determine their effect on bone cells OB & OC and on endothelial cells.

It is well known that cell behaviour in a culture system is influenced by the physiochemical characteristics of the substrate. Human bone derived cells (HBDC) cultured on HT and Sphene supported the HBDC attachment (cells exhibited well defined cytoskeletal structure) showed characteristic features of cellular proliferation and differentiation. In addition, Zn and Ti incorporation into CaSiO3 supported the formation of mature, active and functional OC. Moreover, the modified bio-materials were found to be conducive to Human micro-vascular dermal endothelial cell growth. Our results suggest that HT and Sphene possessed an improved physical characteristics and enhanced biological activities of bone cells (OB & OC) and endothelial cells thus rendering it a potential material for bone tissue regeneration and coatings onto commonly used orthopaedic and dental implants.

CaSiO3 has been used a potential bioactive material for bone regeneration. A drawback of the CaSiO3 ceramics is that they possess high dissolution rate of Ca ions leading to a high pH value environment [1], which can disadvantage cell growth. Zn can enhance osteoconductivity of CaP ceramics and stimulate bone formation [2]. The aims of this study are:

In situ preparation and optimization of Zn-CaSiO3 ceramics by the evaluating of physical and chemical properties, osteoblast and osteoclast behavior;

Zn-CaSiO3 ceramics containing zero, ten, 20 and 50-mol% of Zn were sintered at 1260 °C. The dissolution and apatite formation ability were evaluated by soaking in simulated body fluids. Attachment, proliferation and differentiation of human primary bone-derived cells (HBDC) on ceramic disks were evaluated. Human monocytes isolated from buffy coats were differentiated into mature and functional osteoclast (OC) by culturing them for 21 days on ceramic disks. Then, the optimized HT (50%Zn-CaSiO3) coating on Ti-6Al-4V was prepared by sol-gel spinning method.

The incorporation of Zn in CaSiO3 resulted in part of new phase formation (HT) formation in Zn-Ca-Si ceramics. When adding 50 mol% of Zn, only pure HT phase existed.

The incorporation of Zn in CaSiO3 decreased the dissolution and pure 50 mol% of Zn (HT ceramics) resulted in the lowest dissolution.

Zn-CaSiO3 ceramics with different Zn contents supported HBDC attachment. With the increase of Zn contents, HBDC proliferation and differentiation improved. The surface roughness of Sol-gel HT coating is about 0.49 μm. The thickness of coating is about 1 μm. HT coating has a similar dissolution kinetics and stability with hydroxyapatite coating.

Zn decreases the dissolution in Zn-Ca-Si ceramics and enhances HBDC proliferation and differentiation. The optimized HT ceramics (50mol% Zn) support OC resorption and can be used for a stable biomedical coating application.