Specific lipid magnetic sphere sorted CD146-positive bone marrow mesenchymal stem cells can better promote articular cartilage damage repair.

BACKGROUND: The characteristics and therapeutic potential of subtypes of bone marrow mesenchymal stem cells (BMSCs) are largely unknown. Also, the application of subpopulations of BMSCs in cartilage regeneration remains poorly characterized. The aim of this study was to explore the regenerative capacity of CD146-positive subpopulations of BMSCs for repairing cartilage defects. METHODS: CD146-positive BMSCs (CD146 + BMSCs) were sorted by self-developed CD146-specific lipid magnetic spheres (CD146-LMS). Cell surface markers, viability, and proliferation were evaluated in vitro. CD146 + BMSCs were subjected to in vitro chondrogenic induction and evaluated for chondrogenic properties by detecting mRNA and protein expression. The role of the CD146 subpopulation of BMSCs in cartilage damage repair was assessed by injecting CD146 + BMSCs complexed with sodium alginate gel in the joints of a mouse cartilage defect model. RESULTS: The prepared CD146-LMS had an average particle size of 193.7 ± 5.24 nm, an average potential of 41.9 ± 6.21 mv, and a saturation magnetization intensity of 27.2 Am2/kg, which showed good stability and low cytotoxicity. The sorted CD146 + BMSCs highly expressed stem cell and pericyte markers with good cellular activity and cellular value-added capacity. Cartilage markers Sox9, Collagen II, and Aggrecan were expressed at both protein and mRNA levels in CD146 + BMSCs cells after chondrogenic induction in vitro. In a mouse cartilage injury model, CD146 + BMSCs showed better function in promoting the repair of articular cartilage injury. CONCLUSION: The prepared CD146-LMS was able to sort out CD146 + BMSCs efficiently, and the sorted subpopulation of CD146 + BMSCs had good chondrogenic differentiation potential, which could efficiently promote the repair of articular cartilage injury, suggesting that the sorted CD146 + BMSCs subpopulation is a promising seed cell for cartilage tissue engineering.

CD146-positive adipose-derived stem cells subpopulation enriched by albumin magnetic sphere ameliorates knee osteoarthritis pain and promotes cartilage repair.

BACKGROUND: The use of adipose stem cell (ADSCs) subpopulations in cartilage repair remains poorly characterized. In this study, we constructed an albumin magnetic sphere with specific targeting of CD146 (CD146-AMs) for sorting a subpopulation of CD146-positive ADSCs (CD146 + ADSCs) and explored the role of CD146 + ADSCs on joint pain and cartilage repair in rats with knee osteoarthritis (KOA). METHODS: CD146-AMs were prepared and analyzed in materialistic characterization tests. Subpopulations of CD146 + ADSCs were sorted using CD146-AMs. Surface labeling, viability, and proliferation of a subpopulation of CD146 + ADSCs were evaluated in vitro. Molecular characterization of mRNA and protein expression profiles was analyzed by microarray. A rat KOA pain model was established by the iodoacetic acid method, and KOA pain and the promotion of cartilage repair were assessed after treatment with bilateral joint cavity injections of CD146 + ADSCs. RESULTS: The CD146-AMs prepared in this study had an average particle size of 242.63 ± 6.74 nm, an average potential of 33.82 ± 3.53 mv, and high CD146 targeting and low cytotoxicity. The positive rate of enriched CD146 + ADSCs was 98.21% and showed a high level of stem cell marker expression and good cell viability. Gene and protein expression profiles showed that CD146 + ADSCs have different cellular functions, especially in regulating inflammation. In the KOA model, low, medium and high concentrations of CD146 + ADSCs were able to improve KOA pain and promote cartilage repair in a concentration-dependent trend. CONCLUSIONS: The CD146-AMs prepared in this study were able to safely and efficiently sort out the CD146 + ADSCs subpopulation. The subpopulation of CD146 + ADSCs has a unique molecular profile that ameliorates KOA pain and repairs cartilage damage in rats, providing a new idea for KOA treatment.

The effect of integrity of lesser tuberosity-medial calcar on postoperative outcome in the proximal humeral fracture.

BACKGROUND: In proximal humeral fractures, the medial calcar is often considered an important stabilizing structure. When the medial calcar is disrupted, some patients may have accompanying humeral lesser tuberosity comminution that has not been noticed. To investigate the impacts of comminuted fragments of lesser tuberosity and calcar on postoperative stability, CT results, number of fragments, cortical integrity, and the variation of neck-shaft angle were compared in patients with proximal humeral fractures. MATERIALS AND METHODS: From April 2016 to April 2021, this study included patients with senile proximal humeral fractures diagnosed by CT three-dimensional reconstruction with lesser tuberosity fractures and medial column injuries. The number of fragments in the lesser tuberosity and the continuity of medial calcar were evaluated. Postoperative stability and shoulder function were evaluated by comparing changes in neck-shaft angle and the DASH upper extremity function score from 1 week to 1 year after the operation. RESULTS: A total of 131 patients were included in the study, and the results showed that the number of fragments of the lesser tuberosity was related to the integrity of the medial cortex of the humerus. That is, when there were more than two lesser tuberosity fragments, the integrity of humeral medial calcar was poor. The positive rate of the lift-off test was higher in patients with lesser tuberosity comminutions 1 year after surgery. In addition, patients with more than two lesser tuberosity fragments and continuous destruction of the medial calcar had large variations in the neck-shaft angle, high DASH scores, poor postoperative stability, and poor recovery of shoulder joint function 1 year postoperatively. CONCLUSION: The number of humeral lesser tuberosity fragments and the integrity of the medial calcar were associated with the collapse of the humeral head and the decrease in shoulder joint stability after the proximal humeral fracture surgery. When the number of lesser tuberosity fragments was greater than two and the medial calcar was damaged, the proximal humeral fracture had poor postoperative stability and poor functional recovery of the shoulder joint, which required auxiliary internal fixation treatment.

Morphological Analysis of Fractures of the Proximal Humerus by the Fracture Mapping Technique.

OBJECTIVE: Fractures of different parts of the proximal humerus may lead to different postoperative functional deficits, but there are few studies on the morphology and related functions of the proximal humerus. The purpose of this study was to analyze the fracture pattern of the proximal humerus by the three-dimensional (3-D) fracture mapping technique and to further evaluate its clinical utility. METHODS: Patients with proximal humeral fractures admitted to Pudong Hospital, Fudan University, from January 2018 to December 2020, were analyzed. Three surgeons divided the fractures into groups according to the 3-D CT imaging technique and mapped the fractures on a 3-D template according to the fracture line of each fracture. Finally, the humeral head inversion angle and the functional score were recorded in different fracture types. RESULTS: A total of 312 cases of humeral fractures were included. Among them, there were 90 patients (28.8%) in the simple greater tuberosity + lesser tuberosity + medial cortex group, with typical fracture features of surgical neck fractures of the humerus + greater tuberosity fractures. Eighty-seven patients (27.9%) in the greater tuberosity + isolated fragment lesser tuberosity + medial cortex group had typical "four-part fractures." There were 45 patients (14.4%) in the greater tuberosity + lesser tuberosity + medial isolated fragment group. Moreover, more patients in this group had medial comminution due to varus displacement of the femoral head. There were 66 patients (21.1%) in the isolated greater tuberosity group, 21 patients (6.7%) in the greater tuberosity + lesser tuberosity group, and three patients (1.0%) in the greater tuberosity + medial cortex group. In addition, the humeral head inversion angle and other statistical differences were observed in the greater tuberosity + lesser tuberosity + medial isolated fragment group. CONCLUSIONS: This morphological study helps to further identify the characteristics of proximal humerus fracture patterns, which may be closely related to different clinical outcomes. Further relevant studies are needed to verify the reliability of their clinical application and the potential value in surgical planning and postoperative functional rehabilitation.

Downregulation of the LncRNA MEG3 Promotes Osteogenic Differentiation of BMSCs and Bone Repairing by Activating Wnt/ß-Catenin Signaling Pathway.

BACKGROUND: Previous studies have demonstrated that long non-coding RNA maternally expressed gene 3 (MEG3) emerged as a key regulator in development and tumorigenesis. This study aims to investigate the function and mechanism of MEG3 in osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and explores the use of MEG3 in skull defects bone repairing. METHODS: Endogenous expression of MEG3 during BMSCs osteogenic differentiation was detected by quantitative real-time polymerase chain reaction (qPCR). MEG3 was knockdown in BMSCs by lentiviral transduction. The proliferation, osteogenic-related genes and proteins expression of MEG3 knockdown BMSCs were assessed by Cell Counting Kit-8 (CCK-8) assay, qPCR, alizarin red and alkaline phosphatase staining. Western blot was used to detect ß-catenin expression in MEG3 knockdown BMSCs. Dickkopf 1 (DKK1) was used to block wnt/ß-catenin pathway. The osteogenic-related genes and proteins expression of MEG3 knockdown BMSCs after wnt/ß-catenin inhibition were assessed by qPCR, alizarin red and alkaline phosphatase staining. MEG3 knockdown BMSCs scaffold with PHMG were implanted in a critical-sized skull defects of rat model. Micro-computed tomography(micro-CT), hematoxylin and eosin staining and immunohistochemistry were performed to evaluate the bone repairing. RESULTS: Endogenous expression of MEG3 was increased during osteogenic differentiation of BMSCs. Downregulation of MEG3 could promote osteogenic differentiation of BMSCs in vitro. Notably, a further mechanism study revealed that MEG3 knockdown could activate Wnt/ß-catenin signaling pathway in BMSCs. Wnt/ß-catenin inhibition would impair MEG3-induced osteogenic differentiation of BMSCs. By using poly (3-hydroxybutyrate-co-3-hydroxyhexanoate, PHBHHx)-mesoporous bioactive glass (PHMG) scaffold with MEG3 knockdown BMSCs, we found that downregulation of MEG3 in BMSCs could accelerate bone repairing in a critical-sized skull defects rat model. CONCLUSIONS: Our study reveals the important role of MEG3 during osteogenic differentiation and bone regeneration. Thus, MEG3 engineered BMSCs may be effective potential therapeutic targets for skull defects.

Effect of lesser trochanter posteromedial wall defect on the stability of femoral intertrochanteric fracture using 3D simulation.

BACKGROUND: This study investigated the effects of posteromedial fracture fragments on the postoperative stability of intertrochanteric fractures of the femur by analyzing the quantity and range of fragments in CT 3D reconstruction. MATERIALS AND METHODS: Patients diagnosed with femoral lesser trochanter fractures were collected from September 2015 to February 2018. CT 3D reconstruction was applied to evaluate the quantity and extension of posteromedial fragments and the presence of isolated medial fragments. The stability of postoperative fracture was evaluated by comparing the changes of "neck-shaft angle" and "telescoping" from 1 week to 1 year after operation. RESULTS: A total of 143 patients were finally confirmed, in which 63 patients contained isolated fragments on the medial side, and the average number of fragments in the posteromedial side was 1.93 ± 0.34, which accounted for an average of about 86.11% ± 8.20% in the whole posteromedial wall. When the number of posteromedial fragments was > 2 and the range of posteromedial fragments was > 75%, then the changes in the neck-shaft angle and "telescoping" showed statistical significance (12.27 ± 4.18 mm and 10.13 ± 6.17°, respectively), and when there were isolated medial isolated fragments, then the change in the neck-shaft angle was 10.66 ± 4.27°, showing statistical significance. CONCLUSIONS: These findings revealed a certain correlation between the quantity and the range of posteromedial fragments and the postoperative "shortening" and "collapse" of femoral intertrochanteric fractures.

Does isolated greater trochanter implication affect hip abducent strength and functions in intertrochanteric fracture?

BACKGROUND: A fracture in the isolated greater trochanter is an infrequent type of femoral intertrochanteric fracture. The gluteus medius and gluteus minimus are abducent muscle groups with attachments located on the greater trochanter. Thus, a fracture of the greater trochanter could cause avulsion injury of these attachment points and eventually affect the abducent function of the hip joint and cause chronic pain. Despite these prospects, the impact of a greater trochanter fracture on abducent strength and hip joint function have yet to be investigated. METHODS: Patients who were diagnosed with an isolated greater trochanter fracture (via computed tomography scan and X-ray) and underwent conservative treatment from June 2013 to October 2016 were included in the present study. Magnetic resonance imaging (MRI) was used to verify the morbidity of recessive fractures. Patients' Harris Hip Scores were determined at 3 months, 6 months, and 12 months and the abducent strength and range of motion of the hip joint on the injured side were analyzed and compared to those on the healthy side. RESULT: Among 32 patients, there were 7 individuals diagnosed with isolated greater trochanter fractures by MRI, and 25 individuals whose fractures were found to have extended into the intertrochanteric region, wherein the recessive intertrochanteric region fractures had no relationship with patients' age, gender, or weight. After 12 months of conservative treatment, 7 patients still complained of pain in the hip joint. The average Harris Hip Score was 87.84 ± 4.83, and the abducent range of the hip joint on the injured side (42.02 ± 13.93°) was not significantly different from that of the healthy side (46.24 ± 7.93°). The abducent strength of the hip joint of the injured side was 121.32 ± 41.06 N which was significantly lower than that of healthy side (137.44 ± 42.21 N). CONCLUSION: Results from this investigation suggest that an isolated greater trochanter fracture attenuates the abducent strength of the hip joint, which may be related to injuries of the ligaments and muscles around the greater trochanter. The surgical skills and methods of addressing isolated greater trochanter fractures merit further investigation.

Prognostic value of the c-reactive protein/prognostic nutritional index ratio after hip fracture surgery in the elderly population.

BACKGROUND: More and more older patients receive the surgery after hip fracture. However, the mortality rate is high. Prognostic nutritional index (PNI) is associated with prognosis in hip fracture patients. In the current study, we proposed a novel prognostic score, named c-reactive protein/PNI ratio (CRP/PNI ratio), for predicting the prognosis for geriatric orthopedic population. METHODS: This is a prospective study. Eighty cases of hip fracture surgery in the elderly population were studied to reveal the relationship between the CRP/PNI ratio and the clinicopathological characteristics of the elderly patients. Clinical data included age, sex, weight, length of stay, duration of surgery, comorbidity, and biological data were collected. The primary endpoint was the 1-year mortality rate. RESULTS: Cox regression and log-rank tests were used to evaluate the correlation of CRP/PNI to the one-year mortality. The one-year mortality rate was low in the patients with a low CRP/PNI ratio (P < 0.001). Univariate and multivariate survival analyses proved that CRP/PNI was an important factor to predict the one-year mortality rate of the geriatric hip fracture surgery patients. CONCLUSION: Low CRP/PNI ratio was significantly associated with low one-year mortality rate in older patients after hip fracture surgery.