Chemical composition, crystal size and lattice structural changes after incorporation of strontium into biomimetic apatite

Recently, strontium (Sr) as ranelate compound has become increasingly popular in the treatment of osteoporosis. However, the lattice structure of bone crystal after Sr incorporation is yet to be extensively reported. In this study, we synthesized strontium-substituted hydroxyapatite (Sr-HA) with different Sr content (0.3%, 1.5% and 15% Sr-HA in mole ratio) to simulate bone crystals incorporated with Sr. The changes in chemical composition and lattice structure of apetite after synthetic incorporation of Sr were evaluated to gain insight into bone crystal changes after incorporation of Sr. X-ray diffraction (XRD) patterns revealed that 0.3% and 1.5% Sr-HA exhibited single phase spectrum, which was similar to that of HA. However, 15% Sr-HA induced the incorporation of HPO4(2-) and more CO3(2-), the crystallinity reduced dramatically. Transmission electron microscopy (TEM) images showed that the crystal length and width of 0.3% and 1.5% Sr-HA increased slightly. Meanwhile, the length and width distribution were broadened and the aspect ratio decreased from 10.68+/-4.00 to 7.28+/-2.80. The crystal size and crystallinity of 15% Sr-HA dropped rapidly, which may suggest that the fundamental crystal structure is changed. The findings from this work indicate that current clinical dosage which usually results in Sr incorporation of below 1.5% may not change chemical composition and lattice structure of bone, while it will broaden the bone crystal size distribution and strengthen the bone.

Post-traumatic osteoarthritis following ACL injury

Post-traumatic osteoarthritis (PTOA) develops after joint injury. Specifically, patients with anterior cruciate ligament (ACL) injury have a high risk of developing PTOA. In this review, we outline the incidence of ACL injury that progresses to PTOA, analyze the role of ACL reconstruction in preventing PTOA, suggest possible mechanisms thought to be responsible for PTOA, evaluate current diagnostic methods for detecting early OA, and discuss potential interventions to combat PTOA. We also identify important directions for future research. Although much work has been done, the incidence of PTOA among patients with a history of ACL injury remains high due to the complexity of ACL injury progression to PTOA, the lack of sensitive and easily accessible diagnostic methods to detect OA development, and the limitations of current treatments. A number of factors are thought to be involved in the underlying mechanism, including structural factors, biological factors, mechanical factors, and neuromuscular factor. Since there is a clear "start point" for PTOA, early detection and intervention is of great importance. Currently, imaging modalities and specific biomarkers allow early detection of PTOA. However, none of them is both sensitive and easily accessible. After ACL injury, many patients undergo surgical reconstruction of ACL to restore joint stability and prevent excessive loading. However, convincing evidence is still lacking for the superiority of ACL-R to conservative management in term of the incidence of PTOA. As for non-surgical treatment such as anti-cytokine and chemokine interventions, most of them are investigated in animal studies and have not been applied to humans. A complete understanding of mechanisms to stratify the patients into different subgroups on the basis of risk factors is critical. And the improvement of standardized and quantitative assessment techniques is necessary to guide intervention. Moreover, treatments targeted toward different pathogenic pathways may be crucial to the management of PTOA in the future.

A novel patient-specific navigational template for cervical pedicle screw placement

STUDY DESIGN.: Prospective trial. OBJECTIVE.: To develop and validate a novel, patient-specific navigational template for cervical pedicle placement. SUMMARY OF BACKGROUND DATA.: Owing to the narrow bony anatomy and the proximity to the vertebral artery and the spinal cord, cervical instrumentation procedures demand the need for a precise technique for screw placement. PATIENT.: Specific drill template with preplanned trajectory has been thought as a promising solution for cervical pedicle screw placement. METHODS.: Patients with cervical spinal pathology (n = 25) requiring instrumentation were recruited. Volumetric CT scan was performed on each desired cervical vertebra and a 3-dimensional reconstruction model was generated from the scan data. Using reverse engineering technique, the optimal screw size and orientation were determined and a drill template was designed with a surface that is the inverse of the posterior vertebral surface. The drill template and its corresponding vertebra were manufactured using rapid prototyping technique and tested for violations. The navigational template was sterilized and used intraoperatively to assist with the placement of cervical screws. In total, 88 screws were inserted into levels C2-C7 with 2 to 6 screw in each patient. After surgery, the positions of the pedicle screws were evaluated using CT scan and graded for validation. RESULTS.: This method showed its ability to customize the placement and the size of each screw based on the unique morphology of the cervical vertebra. In all the cases, it was relatively very easy to manually place the drill template on the lamina of the vertebral body during the surgery. The required time between fixation of the template to the lamina and insertion of the pedicle screws was about 80 seconds. Of the 88 screws, 71 screws had no deviation and 14 screws had deviation <2 mm, 1 screw had a deviation between 2 to 4 mm and there were no misplacements. Fluoroscopy was used only once for every patient after the insertion of all the pedicle screws. CONCLUSION.: The authors have developed a novel patient-specific navigational template for cervical pedicle screw placement with good applicability and high accuracy. This method significantly reduces the operation time and radiation exposure for the members of the surgical team. The potential use of such a navigational template to insert cervical pedicle screws is promising. This technique has been clinically validated to provide an accurate trajectory for pedicle screw placement in the cervical spine.

5. Facilitating Positive Health Behaviors and Well-being to Improve Health Outcomes: Standards of Care in Diabetes-2024

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Infrapatellar Fat Pad and Knee Osteoarthritis

Osteoarthritis is the most prevalent arthritis typically characterized by degradation of cartilage. However, its pathogenesis is not fully understood. Currently, osteoarthritis is best considered a disease of the whole "joint organ". Infrapatellar fat pad (IFP), an adipose tissue near synovium, is now attaching importance to researchers for its inflammatory phenotype. In this narrative review, a large body of evidence has been gathered for the involvement of IFP in the development of knee osteoarthritis. Additionally, the underlying mechanisms of how IFP can be involved in this process have been proposed. However, further investigations are needed to better understand its precise role in this process and its underlying mechanism, and beyond that, to develop new strategies to slow down the degenerative process and explore an effective and timely diagnosis of the disease.

Strontium-containing hydroxyapatite bioactive bone cement in revision hip arthroplasty

Clinical outcome of cemented implants to revision total hip replacement (THR) is not as satisfactory as primary THR, due to the loss of bone stock and normal trabecular pattern. This study evaluated a bioactive bone cement, strontium-containing hydroxyapatite (Sr-HA) bone cement, in a goat revision hip hemi-arthroplasty model, and compared outcomes with polymethylmethacrylate (PMMA) bone cement. Nine months after operation, significantly higher bonding strength was found in the Sr-HA group (3.36+/-1.84 MPa) than in the PMMA bone cement group (1.23+/-0.73 MPa). After detached from the femoral component, the surface of PMMA bone cement mantle was shown relatively smooth, whereas the surface of the Sr-HA bioactive bone cement mantle was uneven, by SEM observation. EDX analysis detected little calcium and no phosphorus on the surface of PMMA bone cement mantle, while high content of calcium (14.03%) and phosphorus (10.37%) was found on the surface of the Sr-HA bone cement mantle. Even higher content of calcium (17.37%) and phosphorus (10.84%) were detected in the concave area. Intimate contact between Sr-HA bioactive bone cement and bone was demonstrated by histological and SEM observation. New bone bonded to the surface of Sr-HA cement and grew along its surface. However, fibrous tissue was observed between PMMA bone cement and bone. The results showed good bioactivity of Sr-HA bioactive bone cement in this revision hip replacement model using goats. This in vivo study also suggested that Sr-HA bioactive bone cement was superior to PMMA bone cement in terms of bone-bonding strength. Use of bioactive bone cement may be a possible solution overcoming problems associated with the use of PMMA bone cement in revision hip replacement.

Cell-laden photocrosslinked GelMA-DexMA copolymer hydrogels with tunable mechanical properties for tissue engineering

To effectively repair or replace damaged tissues, it is necessary to design three dimensional (3D) extracellular matrix (ECM) mimicking scaffolds with tunable biomechanical properties close to the desired tissue application. In the present work, gelatin methacrylate (GelMA) and dextran glycidyl methacrylate (DexMA) with tunable mechanical and biological properties were utilized to prepared novel bicomponent polymeric hydrogels by cross-linking polymerization using photoinitiation. We controlled the degree of substitution (DS) of glycidyl methacrylate in DexMA so that they could obtain relevant mechanical properties. The results indicated that copolymer hydrogels demonstrated a lower swelling ratio and higher compressive modulus as compared to the GelMA. Moreover, all of the hydrogels exhibited a honeycomb-like architecture, the pore sizes decreased as DS increased, and NIH-3T3 fibroblasts encapsulated in these hydrogels all exhibited excellent viability. These characteristics suggest a class of photocrosslinkable, tunable mechanically copolymer hydrogels that may find potential application in tissue engineering and regenerative medicine applications.

Interfacial behaviour of strontium-containing hydroxyapatite cement with cancellous and cortical bone

The bone-bonding behaviors of various biomaterials have been extensively investigated. However, the precise mechanisms of bone bonding have not yet been clarified, and the differences in interfacial behaviors of biomaterial bonding with cancellous bone and cortical bone have not yet been understood. In this study, strontium-containing hydroxyapatite (Sr-HA) cement, in which 10% calcium ions were substituted by strontium, was performed in a rabbit hip replacement model. Six months later, the morphology and chemical composition of interfaces between Sr-HA cement with cancellous bone and cortical bone were evaluated by field emission scanning electron microscopy (FESEM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Remarkable differences between these two interfaces were suggested both in morphology and chemical compositions. An apatite layer was found between Sr-HA cement and cancellous bone with a thickness of about 70 microm. However, only a very thin interface (about 1 microm) was formed with cortical bone. As for the cancellous bone/cement interface, high ions intensity of Ca, P, Sr, Na, and O were confirmed by FESEM-EDX and ToF-SIMS. Differences in morphology and chemical component between these two interfaces provided convincing evidences for the proposed dissolution-precipitation coupling mechanism in the formation of biological apatite.

The effect of strontium incorporation in hydroxyapatite on osteoblasts in vitro

The purpose of this study was to test the effects of a series of strontium-substituted HA (Sr-HA) ceramics (0, 1, 5, and 10 mol% Sr substitution) on osteoblasts, thereby demonstrating whether strontium incorporation with HA would favor osteoblast metabolism. Rat primary osteoblasts were cultured with culture media containing ions released from the Sr-HA ceramics as they dissolved. MTT test, alkaline phosphatase activity, osteoblast transcription factor gene (cbfa1) expression and Alizarin Red staining were conducted at different time-points. There is no significant difference in cell proliferation between groups. However, compared with HA group, Sr-HA groups presented significant enhancement with regard to ALP activity, cbfa1 mRNA expression, and mineralization nodules. Among Sr-HA groups, 5 and 10% groups showed much better performances in ALP activity, cbfa1 mRNA expression, and mineralization nodules than 1% group, however, no significant difference was found between 5 and 10% groups. This study has demonstrated that Sr incorporation in HA ceramic enhanced osteoblastic cell differentiation and mineralization. However, further detailed studies are needed to understand the mechanistic effects of this Sr incorporation on osteoblastic cells and the optimal percentage of calcium should be substituted with strontium in HA.

Asporin and osteoarthritis

OBJECTIVE

To provide an overview of the literature describing the role of asporin, a small leucine-rich proteoglycan (SLRP), in osteoarthritis (OA).

METHOD

A literature search was performed and reviewed using the narrative approach.

RESULTS

As a class I SLRP member, asporin, is distinct from other SLRPs. Accumulating evidence demonstrates the involvement of asporin in OA pathogenesis. Many human studies have been conducted to explore the association between the D-repeat polymorphisms and OA susceptibility, but these yield inconsistent results. Possible mechanisms for the involvement of asporin in OA pathology include its influence on TGF-β (transforming growth factor-β) signaling pathways and collagen mineralization. To date, no studies were found to use an asporin-deficient animal model that would help to understand disease mechanisms. Many issues must be addressed to clarify the link between asporin and OA to provide a novel therapeutic strategy for OA, perhaps through controlling and modifying the TGF-β-ECM system.

CONCLUSIONS

Studies examined demonstrate the involvement of asporin in OA pathogenesis, and possible mechanisms by which asporin may be involved in this process have been proposed. However, large-scale interracial studies should be conducted to investigate the association between asporin and OA, and further investigations are needed to obtain a better understanding of the disease mechanism, develop novel therapeutic strategies, and explore new approaches for diagnosis of OA.

Effects of BMSC-Derived EVs on Bone Metabolism

Extracellular vesicles (EVs) are small membrane vesicles that can be secreted by most cells. EVs can be released into the extracellular environment through exocytosis, transporting endogenous cargo (proteins, lipids, RNAs, etc.) to target cells and thereby triggering the release of these biomolecules and participating in various physiological and pathological processes. Among them, EVs derived from bone marrow mesenchymal stem cells (BMSC-EVs) have similar therapeutic effects to BMSCs, including repairing damaged tissues, inhibiting macrophage polarization and promoting angiogenesis. In addition, BMSC-EVs, as efficient and feasible natural nanocarriers for drug delivery, have the advantages of low immunogenicity, no ethical controversy, good stability and easy storage, thus providing a promising therapeutic strategy for many diseases. In particular, BMSC-EVs show great potential in the treatment of bone metabolic diseases. This article reviews the mechanism of BMSC-EVs in bone formation and bone resorption, which provides new insights for future research on therapeutic strategies for bone metabolic diseases.

The role of small leucine-rich proteoglycans in osteoarthritis pathogenesis

OBJECTIVE

To give an overview of the literature on the role of small leucine-rich proteoglycans (SLRPs) in osteoarthritis (OA) pathogenesis.

METHOD

A literature search was performed and reviewed using the narrative approach.

RESULTS

(1) OA is an organ disease with many tissue types and specific roles for each in the pathogenic process. (2) Key biological functions of SLRPs include interacting with collagens to modulate fibril formation, and binding various cell surface receptors and growth factors to influence cellular functions; (3) Accumulating evidence has demonstrated the involvement of SLRPs in OA pathogenesis, most of which came from SLRP-deficient mice models; (4) Possible mechanisms for SLRPs being involved in OA pathogenic process include their roles in the extracellular collagen network, TGF-β signaling pathways, subchondral bone, muscle weakness, and the innate immune inflammation; (5) SLRP-deficient mice offer a potential to understand the molecular mechanisms of OA initiation and progression. (6) Targeting SLRPs may offer a new therapeutic modality for OA through controlling and modifying the TGF-β-ECM system. (7) Monitoring SLRP fragmentation may be a promising biomarker strategy to evaluate OA status.

CONCLUSIONS

Recent literature has shown that SLRPs may play an important role in OA pathogenesis. Possible mechanisms by which SLRPs are involved in this process have also been proposed. However, further investigations are needed in this field to better understand its mechanisms, develop treatments to slow down the degenerative process, and explore new approaches for effective and timely diagnosis of OA.

Tai chi improves physical function in older Chinese women with knee osteoarthritis

BACKGROUND

Tai chi (TC) is proposed as a potential option for the management of osteoarthritis (OA), however, its beneficial effect on patients with knee OA has not been convincing.

OBJECTIVES

To evaluate the effect of a 24-week TC program on physical functions in older Chinese women with knee OA.

METHODS

Thirty-five older Chinese women with knee OA were randomized into TC group (n = 18) and attention control (wellness education and stretching) group (n = 17). Subjects in the TC group practiced the 24-form simplified Yang-style TC 2 to 4 times a week for 24 weeks with frequency gradually increased. Physical function was assessed using the Western Ontario and McMaster University Osteoarthritis Index (WOMAC), 6-minute walk distance and stair climb time.

RESULTS

Compared with the control group, the participants in TC group had statistically significant improvements in changes of the WOMAC total score (6.18 +/- 2.13 vs. 1.71 +/- 2.73, P = 0.000), the WOMAC pain subscale (1.36 +/- 0.22 vs. 0.07 +/- 1.00, P = 0.001), the WOMAC stiffness subscale (0.66 +/- 0.25 vs. 0.05 +/- 0.38, P = 0.043), the WOMAC function subscale (6.17 +/- 1.96 vs. 1.72 +/- 2.63, P = 0.000), the 6-minute walk distance (32.43 +/- 14.20 vs. 6.67 +/- 16.76, P = 0.003), and the stair climb time (2.27 +/- 0.74 vs. 0.27 +/- 1.24, P = 0.001).

CONCLUSIONS

This study suggests that TC provides a safe, feasible and useful exercise option for older Chinese female patients with knee OA.

Strontium-containing hydroxyapatite (Sr-HA) bioactive cement for primary hip replacement: an in vivo study

The purpose of this study was to evaluate the strontium-containing hydroxyapatite (Sr-HA) cement in primary hip replacement, using a rabbit model, and to investigate the histological findings at the cement-implant and bone-cement interfaces under weight-bearing conditions. Unilateral hip replacement was performed with Sr-HA cement or polymethylmethacrylate (PMMA) cement in rabbits and observations were made after 6 months. Good fixation between the Sr-HA cement and implant was observed. Osseointegration of the Sr-HA cement with cancellous bone was widespread. Many multinucleus cells covered the surface of the cement, and resorbed the superficial layer of the cement. By scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis, high calcium and phosphorus levels were detected at the interface with a thickness of about 10 microm. Intimate contact was also observed between the Sr-HA cement and cortical bone without fibrous layer intervening. The overall affinity index of bone on Sr-HA cement was (85.06 +/- 5.40)%, which is significantly higher than that on PMMA cement (2.77%+/- 0.49%). On the contrary, a fibrous layer was consistently observed between PMMA cement and bone, and PMMA cement evoked an inflammatory response and foreign body reaction in the surrounding bony tissues. Results suggested good bioactivity and bone-bonding ability of the Sr-HA cement under weight-bearing conditions.

Factors associated with public attitudes towards persons with disabilities: a systematic review

OBJECTIVE

The aim of this review is to identify and summarize factors that are associated with public attitudes towards people with various disabilities systematically.

METHODS

An electronic search of three databases was performed (Medline, EMBASE and Cochrane) covering the period from 1950 to present. A comprehensive search strategy was developed and the lists of citations were screened for potential eligible studies. Only quantitative studies using valid measurements were included, and the methodological quality of included studies was appraised based on three criteria (sample, measurement, analysis) by two independent reviewers.

RESULTS

The initial electronic search yielded 995 articles after duplicates removed, and 27 studies met the eligibility criteria were included in the study. Three categories of the factors were found to be associated with the public attitudes, which are related to the attitude provider, disabled people, and society respectively. Specifically, the more people know about disabilities, the more likely they were to have positive attitude; and the frequency and quality of the contact with the disabled are also proved to be influential to the attitudes. Meanwhile, the type of disability is also closely correlated to the public's attitude towards the disabilities.

CONCLUSION

People's knowledge of the disability and their contact with individuals with disabilities are the main influential factors in public attitudes towards persons with disabilities.

Causality of genetically determined metabolites and metabolic pathways on osteoarthritis: a two-sample mendelian randomization study

BACKGROUND

Osteoarthritis (OA) is one of the most prevalent musculoskeletal diseases and is the leading cause of pain and disability in the aged population. However, the underlying biological mechanism has not been fully understood. This study aims to reveal the causal effect of circulation metabolites on OA susceptibility.

METHODS

A two-sample Mendelian Randomization (MR) analysis was performed to estimate the causality of GDMs on OA. A genome-wide association study (GWAS) of 486 metabolites was used as the exposure, whereas 8 different OA phenotypes, including any-site OA (All OA), knee and/or hip OA (knee/hip OA), knee OA, hip OA, spine OA, finger and/or thumb OA (hand OA), finger OA, thumb OA, were set the outcomes. Inverse-variance weighted (IVW) was used for calculating causal estimates. Methods including weight mode, weight median, MR-egger, and MR-PRESSO were used for the sensitive analysis. Furthermore, metabolic pathway analysis was performed via the web-based Metaconflict 4.0. All statistical analyses were performed in R software.

RESULTS

In this MR analysis, a total of 235 causative associations between metabolites and different OA phenotypes were observed. After false discovery rate (FDR) correction and sensitive analysis, 9 robust causative associations between 7 metabolites (e.g., arginine, kynurenine, and isovalerylcarnitine) and 5 OA phenotypes were finally identified. Additionally, eleven significant metabolic pathways in 4 OA phenotypes were identified by metabolic pathway analysis.

CONCLUSION

The finding of our study suggested that identified metabolites and metabolic pathways can be considered useful circulating metabolic biomarkers for OA screening and prevention in clinical practice, and can also serve as candidate molecules for future mechanism exploration and drug target selection.

Will ChatGPT/GPT-4 be a Lighthouse to Guide Spinal Surgeons?

The advent of artificial intelligence (AI), particularly ChatGPT/GPT-4, has led to advancements in various fields, including healthcare. This study explores the prospective role of ChatGPT/GPT-4 in various facets of spinal surgical practice, especially in supporting spinal surgeons during the perioperative management of endoscopic spinal surgery for patients with lumbar disc herniation. The AI-driven chatbot can facilitate communication between spinal surgeons, patients, and their relatives, streamline the collection and analysis of patient data, and contribute to the surgical planning process. Furthermore, ChatGPT/GPT-4 may enhance intraoperative support by providing real-time surgical navigation information and physiological parameter monitoring, as well as aiding in postoperative rehabilitation guidance. However, the appropriate and supervised use of ChatGPT/GPT-4 is essential, considering the potential risks associated with data security and privacy. The study concludes that ChatGPT/GPT-4 can serve as a valuable lighthouse for spinal surgeons if used correctly and responsibly.

Intensity-dependent effect of treadmill running on knee articular cartilage in a rat model

OBJECTIVE

To understand the changes of femoral cartilage in response to treadmill running with different intensities in the hope of differentiating "moderate" and "strenuous" running in a rat model.

METHOD

A total of 24 male Wistar rats were randomly assigned into groups of sedentary (SED), low-intensity running (LIR), medium-intensity running (MIR), and high-intensity running (HIR). Rats in LIR, MIR, and HIR groups underwent 8 weeks' treadmill running programs. After sacrificed, femoral condyles were collected to take histomorphometric analysis and immunohistochemistry for collagen II.

RESULTS

Gross and histological observation showed osteoarthritic changes in group HIR. In comparison to SED group, there was significant increase in cartilage thickness, number of chondrocytes, and GAG content in groups LIR and MIR. Conversely, decrease in cartilage thickness, chondrocyte number, and GAG content was found in rats of HIR group, without significant difference though. In addition, in comparison to SED group, HIR group exhibited disorganization of collagen fibril and significantly lower content of collagen type II.

CONCLUSION

An intensity-dependent effect was suggested on the articular cartilage. Our results also demonstrated that running with low-to-medium intensity applied in the present study should be regarded as "moderate" running, whereas high-intensity running as "strenuous" running.

Depression in Osteoarthritis: Current Understanding

Depression, one of the most common comorbidities with osteoarthritis (OA), affects patient prognosis and quality of life. It also increases the overall burden of disease. This subgroup of patients has not been effectively managed in clinical settings. The study aimed to direct physicians' attention to the co-occurrence of depression and OA. Therefore, this review summarizes the relevant literature published over the past 10 years. The focus is on the prevalence of and risk factors for depression in OA, the effects of depression on OA development and treatment response, comorbidity mechanisms, screening, and non-pharmacological treatment. The research on the etiology of depression has been driven largely by epidemiological studies. Recent studies have shown that high levels of pain, poor levels of function, high numbers of OA sites, and slow gait might be associated with depression. However, the pathophysiology of OA and depression comorbidities remains unclear. In addition to immune inflammation and structural changes in the brain, which have been documented in brain imaging studies, psychosocial factors may also play a role. The evidence indicates that depression can be treated with early intervention; however, adjustments may need to be made for individuals with comorbid depression in OA. It is recommended that health care providers pay more attention to depressive symptoms in patients with OA. Clinicians should develop and implement an individualized and comprehensive treatment plan for patients based on a mental health assessment and in teams with other professionals to optimize treatment outcomes.

Delivery of curcumin by directed self-assembled micelles enhances therapeutic treatment of non-small-cell lung cancer

BACKGROUND

It has been widely reported that curcumin (CUR) exhibits anticancer activity and triggers the apoptosis of human A549 non-small-cell lung cancer (NSCLC) cells. However, its application is limited owing to its poor solubility and bioavailability. Therefore, there is an urgent need to develop a new CUR formulation with higher water solubility and better biocompatibility for clinical application in the future.

MATERIALS AND METHODS

In this study, CUR-loaded methoxy polyethylene glycol-polylactide (CUR/mPEG-PLA) polymeric micelles were prepared by a thin-film hydration method. Their characteristics and antitumor effects were evaluated subsequently.

RESULTS

The average size of CUR/mPEG-PLA micelles was 34.9±2.1 nm with its polydispersity index (PDI) in the range of 0.067-0.168. The encapsulation efficiency and drug loading were 90.2%±0.78% and 9.1%±0.07%, respectively. CUR was constantly released from the CUR/mPEG-PLA micelles, and its cellular uptake in A549 cells was significantly increased. It was also found that CUR/mPEG-PLA micelles inhibited A549 cell proliferation, increased the cell cytotoxicity, induced G2/M stage arrest and promoted cell apoptosis. Moreover, the CUR/mPEG-PLA micelles suppressed the migration and invasion of A549 cells more obviously than free CUR. Additionally, CUR/mPEG-PLA micelles inhibited human umbilical vein endothelial cells migration, invasion and corresponding tube formation, implying the antiangiogenesis ability. Its enhanced antitumor mechanism may be related to the reduced expression of vascular endothelial growth factor, matrix metalloproteinase (MMP)-2, MMP-9 and Bcl-2 as well as the increased expression of Bax.

CONCLUSION

The mPEG-PLA copolymer micelles can serve as an efficient carrier for CUR. The CUR/mPEG-PLA micelles have promising clinical potential in treating NSCLC.

MiR-451 suppresses proliferation, migration and promotes apoptosis of the human osteosarcoma by targeting macrophage migration inhibitory factor

Previous studies have shown that MiR-451 plays an important role in human osteosarcoma carcinogenesis, but the underlying mechanism by which MiR-451 affects the osteosarcoma has not been fully understood. This study intends to uncover the mechanism by which MiR-451 functions as a tumor suppressor. The expression of MiR-451 in osteosarcoma tissues and osteosarcoma cell lines was monitored by real-time PCR. The proliferation ability was examined by MTT and cell cycle assay. The migration and apoptosis of cells were monitored by migration assay and flow cytometry, respectively. Moreover, the angiogenesis of HUVEC cells transfected with MiR-451 mimics was examined by tube formation assay. The effect of MiR-451 on MIF was determined by luciferase assays and Western blot assay. The results showed that MiR-451 expression level was significantly reduced in the osteosarcoma compared with normal bone tissues. Overexpression of MiR-451 significantly attenuated the proliferation and migration, and induced the apoptosis of osteosarcoma cells. Furthermore, the angiogenesis of HUVEC cells transfected with MiR-451 mimics was assayed and the decreased angiogenic ability was detected compared to the controls. Finally, we demonstrated that MiR-451 overexpression inhibited the malignant behavior of osteosarcoma by downregulating MIF. These findings suggest that MiR-451 may act as a tumor suppressor in osteosarcoma. MiR-451 inhibited cell proliferation, migration and angiogenesis and promoted apoptosis of human osteosarcoma cells, at least partially, by inhibiting the expression of MIF. MiR-451/MIF may be a novel therapeutic target in treatment of osteosarcoma.

Stem cell therapies in tendon-bone healing

Tendon-bone insertion injuries such as rotator cuff and anterior cruciate ligament injuries are currently highly common and severe. The key method of treating this kind of injury is the reconstruction operation. The success of this reconstructive process depends on the ability of the graft to incorporate into the bone. Recently, there has been substantial discussion about how to enhance the integration of tendon and bone through biological methods. Stem cells like bone marrow mesenchymal stem cells (MSCs), tendon stem/progenitor cells, synovium-derived MSCs, adipose-derived stem cells, or periosteum-derived periosteal stem cells can self-regenerate and potentially differentiate into different cell types, which have been widely used in tissue repair and regeneration. Thus, we concentrate in this review on the current circumstances of tendon-bone healing using stem cell therapy.

Molecular Mechanism of Ferroptosis in Orthopedic Diseases

Ferroptosis is a new iron-dependent programmed cell death process that is directly mediated by the accumulation of lipid peroxides and reactive oxygen species. Numerous studies have shown that ferroptosis is important in regulating the occurrence and development of bone-related diseases, but the underlying mechanisms are not completely clear. Herein, we review the progress of the mechanism of ferroptosis in bone marrow injury, osteoporosis, osteoarthritis, and osteosarcoma and attempt to deeply understand the regulatory targets of ferroptosis, which will open up a new way for the prevention and treatment of orthopedic diseases.

miR-451 inhibits cell growth, migration and angiogenesis in human osteosarcoma via down-regulating IL 6R

Osteosarcoma (OS) has become one of the most common primary malignant tumors in the children and adolescents with a poor prognosis owing to its high malignant and metastatic potential. Although increasing evidence indicates that miR-451 could inhibit the growth and metastasis of OS, its effect on angiogenesis in OS is still very poor. What is more, the mechanism by which miR-451 affects the OS has not been fully elucidated. In the present study, miR-451 was reduced in human osteosarcoma tissues compared with the adjacent bone tissues, and the introduction of miR-451 dramatically inhibited the growth, migration and angiogenesis in OS. Additionally, it was suggested that IL 6R is a direct target gene of miR-451. Silencing of IL 6R suppressed the growth, migration and angiogenesis of OS, which was consistent with the effect of overexpression of miR-451. In conclusion, our data demonstrate that miR-451 may function as a potential suppressor of tumor growth, migration and angiogenesis in OS via down-regulating IL 6R, suggesting a promising therapeutic avenue for managing OS.