Antioxidant flavonoid-loaded nano-bioactive glass bone paste: in vitro apatite formation and flow behavior.

Non-cement pastes in the form of injectable materials have gained considerable attention in non-invasive regenerative medicine. Different osteoconductive bioceramics have been used as the solid phase of these bone pastes. Mesoporous bioactive glass can be used as an alternative bioceramic for paste preparation because of its osteogenic qualities. Plant-derived osteogenic agents can also be used in paste formulation to improve osteogenesis; however, their side effects on physical and physicochemical properties should be investigated. In this study, nano-bioactive glass powder was synthesized by a sol-gel method, loaded with different amounts of quercetin (0, 100, 150, and 200 µM), an antioxidant flavonoid with osteogenesis capacity. The loaded powder was then homogenized with a mixture of hyaluronic acid and sodium alginate solution to form a paste. We subsequently evaluated the rheological behavior, injectability, washout resistance, and in vitro bioactivity of the quercetin-loaded pastes. The washout resistance was found to be more than 96% after 14 days of immersion in simulated body fluid (SBF) as well as tris-buffered and citric acid-buffered solutions at 25 °C and 37 °C. All pastes exhibited viscoelastic behavior, in which the elastic modulus exceeded the viscous modulus. The pastes displayed shear-thinning behavior, in which viscosity was more influenced by angular frequency when the quercetin content increased. Results indicated that injectability was much improved using quercetin and the injection force was in the range 20-150 N. Following 14 days of SBF soaking, the formation of a nano-structured apatite phase on the surfaces of quercetin-loaded pastes was confirmed through scanning electron microscopy, X-ray diffractometry, and Fourier-transform infrared spectroscopy. Overall, quercetin, an antioxidant flavonoid osteogenic agent, can be loaded onto the nano-bioactive glass/hyaluronic acid/sodium alginate paste system to enhance injectability, rheological properties, and bioactivity.

Prediction of hamstring tendon autograft diameter using preoperative measurements with different cut-offs between genders.

PURPOSE: Studies have suggested some predictors for hamstring tendon (HT) autograft diameter based on anthropometric factors and preoperative magnetic resonance imaging (MRI) with variable results. Some authors have attributed the variability to gender differences. This prospective cohort reports the sensitivity and specificity of anthropometric and MRI predictors in males and females separately to determine the difference. METHODS: Forty-two eligible patients who underwent anterior cruciate ligament reconstruction (ACLR) and MRI in our center were included. ACLR was performed by the senior surgeon using a 4-stranded HT autograft for all patients. A blinded musculoskeletal radiologist measured the cross-sectional area (CSA) of gracilis and semitendinosus tendons using the free-hand region of interest tool for all patients. An orthopaedic resident (PGY4) collected anthropometric factors and measured intraoperative autograft diameter. RESULTS: Mean intraoperative autograft diameter was 8.0 mm. Females had a significantly lower autograft diameter (7.4 vs. 8.2, P < 0.001), smaller gracilis (6.9 vs. 7.9, P = 0.003) and semitendinosus CSA (11.5 vs. 12.8, P = 0.014) compared to males. ROC curve analysis resulted different cut-off values with high sensitivity and specificity for semitendinosus and combined CSA regarding gender. CONCLUSION: Based on the results of this study, CSA of either isolated or combined HTs on preoperative axial MRI, height, and weight are the strongest predictors of intraoperative autograft diameter. It is suggested to consider different cut-offs for males and females to have a better clinical guide for surgeons. LEVEL OF EVIDENCE: Level II.

Biomimetic reduced graphene oxide coated collagen scaffold for in situ bone regeneration.

A variety of bone-related diseases and injures and limitations of traditional regeneration methods require new tissue substitutes. Tissue engineering and regeneration combined with nanomedicine can provide different natural or synthetic and combined scaffolds with bone mimicking properties for implantation in the injured area. In this study, we synthesized collagen (Col) and reduced graphene oxide coated collagen (Col-rGO) scaffolds, and we evaluated their in vitro and in vivo effects on bone tissue repair. Col and Col-rGO scaffolds were synthesized by chemical crosslinking and freeze-drying methods. The surface topography, and the mechanical and chemical properties of scaffolds were characterized, showing three-dimensional (3D) porous scaffolds and successful coating of rGO on Col. The rGO coating enhanced the mechanical strength of Col-rGO scaffolds to a greater extent than Col scaffolds by 2.8 times. Furthermore, Col-rGO scaffolds confirmed that graphene addition induced no cytotoxic effects and enhanced the viability and proliferation of human bone marrow-derived mesenchymal stem cells (hBMSCs) with 3D adherence and expansion. Finally, scaffold implantation into rabbit cranial bone defects for 12 weeks showed increased bone formation, confirmed by Hematoxylin-Eosin (H&E) and alizarin red staining. Overall, the study showed that rGO coating improves Col scaffold properties and could be a promising implant for bone injuries.

Mussel-inspired polydopamine induced the osteoinductivity to ice-templating PLGA-gelatin matrix for bone tissue engineering application.

In this study, poly(lactic-co-glycolic acid) (PLGA)-gelatin scaffolds were fabricated using the freeze-casting technique. Polydopamine (PDA) coating was applied on the surface of scaffolds to enhance the hydrophilicity, bioactivity, and cellular behavior of the composite constructs. Further, the synergistic effect of PDA coating and lamellar microstructure of scaffolds was evaluated on the promotion of properties. Based on morphological observations, freeze-casting constructs showed lamellar pore channels while the uniformity and pore size were slightly affected by deposition of PDA. The hydrophilicity and swelling capacity of the scaffolds were assessed using contact angle measurement and phosphate buffered saline absorption ratio. The results indicated a significant increment in water-matrix interactions following surface modification. The evaluation of the biodegradation ratio revealed the higher degree of degradation in PDA-coated samples owing to the presence of hydrophilic functional groups in the chemical structure of PDA. On the other hand, the bioactivity potential of PDA in the simulated body fluid solution confirmed the possibility of using coated constructs as a bone reconstructive substitute. The improvement of cellular attachment and filopodia formation in PDA-contained matrixes was the other benefit of the coating process. Furthermore, cellular proliferation and ALP activity were enhanced after PDA coating. The suggested PDA-coated PLGA-gelatin scaffolds can be applied in bone tissue regeneration.

Outcomes of Tibial Plateau Fracture Surgical Fixation: a Comparative Study between Younger and Older Age Groups.

BACKGROUND: Tibial plateau fractures account for approximately 8% of the fractures of the elderly. Low bone quality that is more common in the elderly is one of the major challenges in fixing fractures and may be a barrier to achieving satisfactory outcomes after a surgical fracture treatment. Accordingly, surgical fixation of tibial plateau fractures was controversial in the elderly. This study aimed to investigate and compare the clinical outcomes of surgical fixation in patients over and under 60 years of age. METHODS: This study was conducted as a retrospective cohort study of data that were prospectively collected. In total, 48 patients who underwent surgery with open reduction and internal fixation before August 2019 were recruited and followed up at least one year after surgery. Demographic characteristics, the range of motion of the knees, visual analog scale (VAS) score of pain intensity, and the Oxford Knee Score (OKS) were obtained in this study. Furthermore, Short Form-36 (SF-36) questionnaire was used to evaluate patient satisfaction. RESULTS: In total, 19 and 29 patients were over and under 60 years of age, respectively. According to Schatzker's classification, the most common type of fracture was type VI. The range of motion in the knees did not differ significantly between the two groups (P>0.05). Moreover, OKS and the VAS of pain intensity were not significantly different in both groups (P>0.05). In addition, SF-36 scores were not significantly different between elderly patients and the age-matched general population. However, younger patients had lower scores in the physical function and vitality scales of SF-36, compared to the age-matched general population. CONCLUSION: Based on the results of the present study, it can be stated that increasing age did not affect the surgical outcomes of patients with tibial plateau fractures.

Biomechanical Evaluation of Temperature Rising and Applied Force in Controlled Cortical Bone Drilling: an Animal in Vitro Study.

BACKGROUND: The present study was conducted to quantify the relationships between bone drilling process parameters (i.e., feed rate, resting time, exit rate, and drill bit diameter) and drilling outcome parameters (i.e., thrust force and maximum temperature). METHODS: This study utilized 10-cm cortical bovine samples to evaluate the effects of four independent parameters, including drill bit diameters, six different feed rates, three various resting times, and three different exit rates on thrust force and maximum temperature (MT). A total of 28 stainless steel orthopedic drill bits with a diameter of 2.5 and 3.2 mm, as well as an orthopedic handpiece were attached to the 500N load cell and an accurate linear variable differential transformer to obtain forces. Moreover, two k-type thermocouples were utilized to record the temperature-time curve near the drilling site. The data were analyzed using the two-way analysis of variance and post hoc Tukey-Kramer Honest test. RESULTS: Maximum thrust force (MTF) decreased by almost 230% as the drill bit diameter increased from 2.5 to 3.2 mm in the lowest feed rate. The MTF showed a 335% increase, whereas a decrease of 69% was observed as the feed rates rose from 0.5 to 3 mm/sec. Moreover, the MT decreased to 67% with an increasing exit rate from 1 to 3 mm/sec. Furthermore, a slight increase was observed in MT when the resting time increased from 0 to 2 seconds (P>0.05). CONCLUSION: The desired drilling is drilling with lower thrust force and lower final temperature of bone. Increasing feed rate can cause an increase and decline in thrust force and final temperature, respectively. The highest rates of MT were 0.5 and 1 mm/min, and the optimum feed rate would be 1.5 mm/min due to the averaged thrust force. Moreover, the resting time had no significant effects on the final temperature. Attentions to resting time would be useful to provide a more accurate, efficient, and uniform drill hole.

Relation of the chondromalatia patellae to proximal tibial anatomical parameters, assessed with MRI.

Background Magnetic resonance imaging (MRI) is a non-invasive highly sensitive tool for diagnosing chondromalacia patellae in the early stages. Many studies have evaluated patellar and trochlear morphology with different radiologic indices. We aimed to assess the discriminative power of tibial, patellar, and femoral indices in MRI for chondromalacia patellae. Patients and methods 100 cases of chondromalacia, as well as 100 age-matched controls among the patients who underwent knee MRI between February 2017 and March 2019, were included. The standard protocol of knee MRI was applied and the diagnosis of chondromalacia was made on MRI findings. Chondromalacia subjects were also classified as grade 1 to 4 according to the Modified Outerbridge's MRI grading system. We measured 25 MRI parameters in the knee and adjacent structures to determine the relation between chondromalacia patellae and anatomical MRI parameters. Results Tibial slope, trochlear depth, lateral trochlear inclination, and lateral patellar tilt angle had significant correlation with chondromalacia. Any increase in lateral trochlear inclination and lateral patellar tilt angle could increase the probability of the disease (Odds ratio [OR] 1.15, 1.13; 95% CI: 1.03-1.30; 1.02-1.26, respectively), while any increase in medial tibial slope and trochlear depth could decrease the probability of chondromalacia (OR 0.85, 0.06; 95% CI: 0.73-0.98, 0.02-0.17, respectively). We also designed a model for the severity of disease by using the patellar height index (relative odds ratio: 75.9). Conclusions The result of this study showed the novelty role of tibial anatomy in developing chondromalacia and its mechanism. We also concluded that patellar height might be an important factor in defining disease severity.

Effectiveness of Platelet-ich Plasma Based on Gene Expression in Knee Osteoarthritis.

BACKGROUND: Intra-articular injection of Platelet-rich plasma (PRP) is an effective method for the treatment of patients with knee osteoarthritis (OA). This study aimed to assess the effects of PRP injection on OA, based on gene expression analysis. METHODS: A sample of 30 subjects with knee OA was asked to complete the Persian versions of the Intermittent and Constant Osteoarthritis Pain (ICOAP) and Knee and Osteoarthritis Outcome Score (KOOS). Thereafter, the expression of IGF-1, HIF-1, cartilage oligometric matrix protein (COMP), and bone morphogenetic proteins (BMP2) were compared in the patient before and 1 month after PRP injection using real-time polymerase chain reaction (PCR). RESULTS: According to the results of the study, the expression of IGF-1, HIF-1, COMP and BMP2 were reported to be higher in subjects with PRP injection; however, only the up-regulation of IGF-1 was statistically significant (P<007). Moreover, the significant change in the KOOS and ICOAP scores was attributed to PRP injection (P<0.01). CONCLUSION: Intra-articular injections of PRP were reported to ease the pain, decrease the stiffness, and improve quality of life in patients with knee OA through the promotion of IGF-1 expression.

Proximal Tibiofibular Joint Inclination Angle and Associated Meniscal Tear in Patients with Discoid Lateral Meniscus.

Background and objectives:Discoid lateral meniscus (DLM) is the most common congenital variant of a meniscus with a high prevalence meniscal tear due to abnormal shape and behavior. The proximal tibiofibular joint (PTFJ) has an important role during knee extension and ankle dorsiflexion. The aim of this research is to study the association between PTFJ morphology in MRI and DLM and its pathologies as compared with the normal lateral meniscus in Iranian population. Materials and methods:Totally, 1729 MRI scans were reviewed, and 69 scans were selected based on inclusion/exclusion criteria. A group of aged-matched control patients without DLM were also included in this study. MRI scans were studied for DLM, meniscal tear and PTFJ inclination angle (horizontal or oblique). Findings were compared with those of patients without DLM. Results:The frequency of horizontal-type PTFJ was significantly higher in the DLM group than in the control group. We also found a strong association (p value=0.018) between horizontal-type PTFJ and meniscal tear as compared with oblique-type in patients with DLM. Conclusion:Horizontal-type PTFJ is more prevalent in patients with DLM. The meniscal tear is also more frequently seen in patients with DLM and horizontal-type PTFJ. Larger prospective studies are needed to confirm these results.

Transforming growth factor-ß3 relation with osteoporosis and osteoporotic fractures.

BACKGROUND: The high socioeconomic impact of osteoporosis and osteoporotic fracture is due to their high mortality, morbidity, and disease-related costs. Nowadays, bone mineral density (BMD) is a comparatively expensive way to diagnose and follow up patients with osteoporosis. Transforming growth factor-ß3 (TGF-ß3) is a protein categorized into cytokines. Some previous in vitro studies showed TGF-ß3 effects on osteocytes and bone formation. Therefore, we conducted this study to find if there is any significant relationship between TGF-ß3 and BMD results. MATERIALS AND METHODS: This was an analytical cross-sectional study conducted in 2017. We included individuals who had been referred from their physicians to undergo BMD dual-energy X-ray absorptiometry. Blood samples were taken from 150 participants for measuring TGF-ß3 with ELISA method. RESULTS: The mean ± standard deviation of TGF-ß3 serum level was 79 ± 30.8 pg/ml (minimum 41 pg/ml and maximum 210 pg/ml). There was a statistically significant and direct proportional relationship between TGF-ß3 and T-score as a marker for the diagnosis and follow-up of osteoporosis and osteoporotic fracture (P = 0.001) (Pearson's correlation = +0.95). CONCLUSION: There was a significant relationship between TGF-ß3 serum level and BMD. TGF-ß3 serum level may be used as a marker for the diagnosis and follow-up of osteoporosis and osteoporotic fracture.

In vitro and in vivo investigation of PLA/PCL scaffold coated with metformin-loaded gelatin nanocarriers in regeneration of critical-sized bone defects.

Large bone defects constitute a major challenge in bone tissue engineering and usually fail to heal due to the incomplete differentiation of recruited mesenchymal stem cells (MSCs) into osteogenic precursor cells. As previously proposed, metformin (MET) induces differentiation of MSCs into osteoblastic lineages in vitro. We fabricated a Poly (lactic acid) and Polycaprolactone (PLA/PCL) scaffold to deliver metformin loaded gelatin nanocarriers (MET/GNs) to critical-sized calvarial bone defects in a rat model. The scaffolds were evaluated regarding their morphology, porosity, contact angle, degradation rate, blood compatibility, biomechanical, cell viability and their osteogenic differentiation. In animal study, the defects were filled with autograft, scaffolds and a group was left empty. qRT-PCR analyses showed the expression level of osteogenic and angiogenic markers considerably increased in MET/GNs-PLA/PCL. The in vivo results showed that MET/GNs-PLA/PCL improved bone ingrowth, angiogenesis and defect reconstruction. Our results represent the applicability of MET/GNs-PLA/PCL for successful bone regeneration.

Studying the effects of primary arthroplasty on post-treatment results among elderly patients with pertrochanteric fracture.

Various therapeutic methods are available to treat patients with intertrochantric fracture, which is usually caused by falling down. This complication is usually observed among the elderly, particularly old women. The choice of the proper therapeutic method depends on many factors including patient's condition, type of fracture, and the amount of movement. Hip arthroplasty is one of these therapeutic methods, which have certain advantages and disadvantages. Immediate resumption of walking with the ability of weight toleration and absence of complications such as aseptic necrosis are some advantages of this method. Sixtyeight elderly patients with pertrochanteric fracture who had resorted to Iranian Army's hospitals and had undergone arthroplasty. These cases were examined with due comparison with historical and external controls. Variables such a type of operation, age, post-operation pain, the pace of resuming walking ability, embolism, surgical site infection, bedsore and DVT were studied and compared against standard operation. The results achieved through assessment of variables showed a significant difference with standard operation in terms of variables such as post-operative movement ability, pain scale in various times, surgical complications, embolism, surgical site infection, bedsore, and DVT. Post-operative pain within the first 3 months following it are some complications with not much attention is paid to them, but they are important complications which can cause many negative and influential effects on patients. Arthroplasty is more expensive than standard operation and the patient may initially feel more pain.

Comparative impact of systemic delivery of atorvastatin, simvastatin, and lovastatin on bone mineral density of the ovariectomized rats.

PURPOSE: In addition to lipid-lowering properties, statins have been suggested to affect bone turnover by increasing the osteoblastic bone formation and blocking the osteoclastogenesis. However, there are many controversial reports regarding the beneficial effect of statins on osteoporosis. In this study, we investigated the therapeutic effects of the most important lipophilic statins administered orally for 60 days to the ovariectomized (OVX) female Sprague-Dawley rats and compared the effects on different harvested trabecular and compact bones. METHODS: Thirty female rats were divided into five equal groups including the normal rats, untreated OVX rats (negative control), and the OVX rats treated with atorvastatin (20 mg/kg/day), simvastatin (25 mg/kg/day), and lovastatin (20 mg/kg/day). The osteoporotic animals were treated daily for 60 days and euthanized at the end of experiments. The effectiveness of these treatments was evaluated by biomechanical testing, histopathologic, histomorphometric, micro-CT scan, real-time PCR, and serum biochemical analysis. Moreover, the hepatotoxicity and rhabdomyolysis related with these treatments were assessed by biochemistry analysis and histopathological evaluation. RESULTS: The results and statistical analysis showed that systemic delivery of simvastatin and lovastatin significantly increased serum calcium level, expression of osteogenic genes, bone mineral density (BMD), and biomechanical properties in comparison to the untreated OVX rats, especially in trabecular bones (P < 0.05). The results of different analysis also indicated that there was no statistical difference between the atorvastatin-treated animals and the negative control. Among all treatments, only atorvastatin showed an evident hepatotoxicity and myopathy. CONCLUSIONS: It was concluded that the lovastatin and simvastatin efficiently ameliorated the OVX-induced osteoporosis. Moreover, the simvastatin-treated animals showed more resemblance to the normal group in terms of BMD, expression of osteogenic genes, serum biochemical parameters, histomorphometric findings, and biomechanical performance with no significant side-effects.

Physicochemical properties and bioactivity of freeze-cast chitosan nanocomposite scaffolds reinforced with bioactive glass.

Chitosan based nanocomposite scaffolds were prepared by freeze casting method through blending constant chitosan concentration with different portions of synthesized bioactive glass nanoparticles (BGNPs). Transmission Electron Microscopy (TEM) image showed that the particles size of bioactive glass (64SiO2.28CaO.8P2O5) prepared by sol-gel method was approximately less than 20 nm. Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray Diffraction (XRD) analysis showed proper interfacial bonding between BGNPs and chitosan polymers. Scanning Electron Microscopy (SEM) images depicted a unidirectional structure with homogenous distribution of BGNPs among chitosan matrix associated with the absence of pure chitosan scaffold's wall pores after addition of only 10 wt.% BGNPs. As the BGNP content increased from 0 to 50 wt.%, the compressive strength and compressive module values increased from 0.034 to 0.419 MPa and 0.41 to 10.77 MPa, respectively. Biodegradation study showed that increase in BGNP content leads to growth of weight loss amount. The in vitro biomineralization studies confirmed the bioactive nature of all nanocomposites. Amount of 30 wt.% BGNPs represented the best concentration for absorption capacity and bioactivity behaviors.

Three-Dimensional Porous Gelapin-Simvastatin Scaffolds Promoted Bone Defect Healing in Rabbits.

Treatment of large bone defects (LBDs) is technically demanding. Tissue engineering is an option. A bioactive graft may be produced by combining tissue scaffolds and healing promotive factors in order to accelerate bone repair. We investigated the role of Simvastatin (Sim)-embedded porous Gelapin (Gel) scaffold on experimental bone healing. At first, the effectiveness of different concentrations of Gel and Sim powders was investigated in an experimentally induced femoral hole model in rabbits (n = 6) for 30 days. Then bone bioactive grafts were produced by combination of the effective concentrations of Gel, Sim, and Genipin. The bioimplants were subcutaneously tested in a rabbit model (n = 9) to determine their biocompatibility and biodegradability for 10-30 days. Finally, a large radial bone defect model was produced in rabbits (n = 20), and the bioimplants were inserted in the defects. The untreated and autograft-treated bone defects were served as controls. The animals were euthanized after 30 and 60 days of bone injury. The bone samples were evaluated by radiography, three-dimensional CT scan, bone densitometry, histopathology, and nano-indentation. At a concentration of 5 mg/hole, Sim closed the femoral bone holes after 30 days, while in the defect, autograft, and Gel groups, the holes were open. Both the Gel and Gel-Sim scaffolds were biocompatible and biodegradable. Subcutaneously, the Gel-Sim scaffold was replaced with the newly regenerated ectopic bone after 30 days. After implantation of the Gel-Sim scaffold in the radial bone defects, the scaffold was completely replaced with new woven bone after 30 days which was then matured and remodeled into a cortical bone after 60 days. Sixty days after bone injury, the Gel-Sim-treated defects had significantly higher bone volume, matrix mineralization, elastic modulus, and contact hardness when compared to the controls. The Gel-Sim scaffold may be a suitable option in managing LBDs.