Statins augment vascular endothelial growth factor expression in osteoblastic cells via inhibition of protein prenylation

Advances in Hydrogels for Periodontitis Treatment

Periodontitis is a common condition characterized by a bacterial infection and the disruption of the body's immune-inflammatory response, which causes damage to the teeth and supporting tissues and eventually results in tooth loss. Current therapy involves the systemic and local administration of antibiotics. However, the existing treatments cannot exert effective, sustained release and maintain an effective therapeutic concentration of the drug at the lesion site. Hydrogels are used to treat periodontitis due to their low cytotoxicity, exceptional water retention capability, and controlled drug release profile. Hydrogels can imitate the extracellular matrix of periodontal cells while offering suitable sites to load antibiotics. This article reviews the utilization of hydrogels for periodontitis therapy based on the pathogenesis and clinical manifestations of the disease. Additionally, the latest therapeutic strategies for smart hydrogels and the main techniques for hydrogel preparation have been discussed. The information will aid in designing and preparing future hydrogels for periodontitis treatment.

NIR-responsive magnesium phosphate cement loaded with simvastatin-nanoparticles with biocompatibility and osteogenesis ability

The insufficient osteogenesis of magnesium phosphate cement (MPC) limits its biomedical application. It is of great significance to develop a bioactive MPC with osteogenic performance. In this study, an injectable MPC was reinforced by the incorporation of a near infrared (NIR)-responsive nanocontainer, which was based on simvastatin (SIM)-loaded mesoporous silica nanoparticles (MSNs) modified with a polydopamine (PDA) bilayer, named SMP. In addition, chitosan (CHI) was introduced into MPC (K-struvite) to enhance its mechanical properties and cytocompatibility. The results showed that nanocontainer-incorporated MPC possessed a prolonged setting time, almost neutral pH, excellent injectability, and enhanced compressive strength. Immersion tests indicated that SMP-CHI MPC could suppress rapid degradation. Based on its physicochemical features, the SMP-CHI MPC had good biocompatibility and osteogenesis properties, as shown via in vitro and in vivo experiments. These findings can provide a simple way to produce a multifunctional MPC with improved osteogenesis for further orthopedic applications.

Efficacy of spongy xenogeneic scaffold loaded with simvastatin in the treatment of severe alveolar horizontal defect: A clinical and histological study

Background

Bone tissue engineering offers several advantages for repairing skeletal defects. In this study, we designed and fabricated a scaffold for bone tissue engineering in patients with horizontal alveolar defect.

Aim

The items included in the fabrication of the scaffold were xenogenic bone graft, gelatin as a substrate to improve the physical integrity of scaffold, and simvastatin to stimulate osteogenesis (10 mg per 1 g of xenograft).

Methods

Fourteen patients with a horizontal defect in the alveolar ridge were enrolled in the study. Seven patients underwent routinely guided bone regeneration (GBR) using xenogenic bone graft plus collagenous membrane, and seven patients were treated with the scaffolds. After four months of follow-up after surgery, both the scaffold and GBR groups were examined for changes in the width of alveolar ridge and histologically for the quantity of newly produced bone.

Results

The newly designed scaffold showed superior osteoconduction characteristics to routine GBR materials, which were used in this study. The difference in the quantity of the newly produced bone between the scaffold group and GBR group was significant and higher for the scaffold group. Regarding newly produced bone percentage, the scaffold group showed a mean of 20.93 and the GBR group presented a mean of 13.25% (P = 0.004). Also, the mean value for the duration of surgery for GBR was 45 minutes and for scaffold was 22 minutes, which was significantly lower in the scaffold group (P < 0.001).

Conclusions

The newly designed scaffold is a suitable treatment modality for bone tissue engineering.

Effects of Hyperlipidemia on Osseointegration of Dental Implants and Its Strategies

Hyperlipidemia refers to the abnormal increase in plasma lipid level exceeding the normal range. At present, a large number of patients require dental implantation. However, hyperlipidemia affects bone metabolism, promotes bone loss, and inhibits the osseointegration of dental implants through the mutual regulation of adipocytes, osteoblasts, and osteoclasts. This review summarized the effects of hyperlipidemia on dental implants and addressed the potential strategies of dental implants to promote osseointegration in a hyperlipidemic environment and to improve the success rate of dental implants in patients with hyperlipidemia. We summarized topical drug delivery methods to solve the interference of hyperlipidemia in osseointegration, which were local drug injection, implant surface modification and bone-grafting material modification. Statins are the most effective drugs in the treatment of hyperlipidemia, and they also encourage bone formation. Statins have been used in these three methods and have been found to be positive in promoting osseointegration. Directly coating simvastatin on the rough surface of the implant can effectively promote osseointegration of the implant in a hyperlipidemic environment. However, the delivery method of this drug is not efficient. Recently, a variety of efficient methods of simvastatin delivery, such as hydrogels and nanoparticles, have been developed to boost bone formation, but few of them were applied to dental implants. Applicating these drug delivery systems using the three aforementioned ways, according to the mechanical and biological properties of materials, could be promising ways to promote osseointegration under hyperlipidemic conditions. However, more research is needed to confirm.

SPARC is a decoy counterpart for c‑Fos and is associated with osteoblastic differentiation of bone marrow stromal cells by inhibiting adipogenesis

Secreted protein acidic and rich in cysteine (SPARC), also called basement‑membrane protein 40 or osteonectin, is a matricellular protein that is abundant not only in bone tissue as a non‑collagenous protein but is also ubiquitously expressed in non‑calcified tissue. SPARC is located intracellularly and disruption of the Sparc gene has been reported to reduce bone formation and increase fat tissue; however, the mechanism by which SPARC inhibits adipogenesis remains unclear. The present study evaluated the intracellular function of SPARC in adipogenesis using the bone marrow stromal cell line ST2. When ST2 cells with low SPARC production were cloned, intrinsic activator protein‑1 (AP‑1) activity was markedly higher, mineralized nodule formation was significantly lower and lipid accumulation was significantly increased compared with in the parental ST2 cells. Forced expression of secreted SPARC with the signal peptide‑coding sequences of wild‑type Sparc or preprotrypsin in SPARC‑low ST2 cells significantly reduced AP‑1 transcription activity; however, these reductions were not observed in the absence of signal peptide sequences. Recombinant SPARC, produced using Brevibacillus brevis, specifically bound to c‑Fos but not c‑Jun and inhibited the binding of c‑Fos/c‑Jun to a TPA‑response element sequence. These data suggested that SPARC was incorporated into the cells from the extracellular spaces and serves an intracellular role as a decoy counterpart for c‑Fos, as well as being associated with osteoblastogenesis through the inhibition of adipogenesis. These findings may provide new insights into regenerative medicine.

Effect of simvastatin on osteogenesis of the extremity bones in aging rats

PURPOSE

Simvastatin is a prodrug of the potent 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor. The main purpose of the current study is to assess the accurate function of simvastatin on osteoporosis of extremity bones in aging rats.

MATERIALS AND METHODS

Fifty 15-month-old SD rats were divided into five groups (four simvastatin groups and one control group). The rats in four simvastatin groups were fed with different doses of simvastatin (5, 10, 20, and 40 mg/kg/d, respectively) for 3 months, whereas the rats in control group were fed the equal physiological saline. Calcium (Ca), phosphorus (P), and the lipid spectrum in serum were measured. Biochemical markers of bone metabolism, osteocalcin (OC), and tartrate-resistant acid phosphatase (Trap-5b), were analyzed using ELISA. The content of adipocytes in bone marrow was analyzed by histological staining. Finally, the bone quality of the femur and tibia were evaluated using dual-energy X-ray absorptiometry (DEXA), peri-quantity CT (pQCT), and the 3-point bending biomechanical test.

RESULTS

Simvastatin reduced serum triglycerides (TG), and 10 mg/kg/d of simvastatin significantly reduced the content of adipocytes in bone marrow compared to the control group. However, statistically significant differences between the simvastatin groups and the control group were not found in the CA, P, OC, Trap-5b, or the evaluation indexes of bone quality from DEXA, pQCT, and biomechanical tests.

CONCLUSION

Simvastatin could not prevent osteoporosis of the extremity bones in aging rats.

Pathogenesis and management of traumatic brain injury (TBI): role of neuroinflammation and anti-inflammatory drugs

Traumatic brain injury (TBI) is an important global health concern that represents a leading cause of death and disability. It occurs due to direct impact or hit on the head caused by factors such as motor vehicles, crushes, and assaults. During the past decade, an abundance of new evidence highlighted the importance of inflammation in the secondary damage response that contributes to neurodegenerative and neurological deficits after TBI. It results in disruption of the blood-brain barrier (BBB) and initiates the release of macrophages, neutrophils, and lymphocytes at the injury site. A growing number of researchers have discovered various signalling pathways associated with the initiation and progression of inflammation. Targeting different signalling pathways (NF-κB, JAK/STAT, MAPKs, PI3K/Akt/mTOR, GSK-3, Nrf2, RhoGTPase, TGF-β1, and NLRP3) helps in the development of novel anti-inflammatory drugs in the management of TBI. Several synthetic and herbal drugs with both anti-inflammatory and neuroprotective potential showed effective results. This review summarizes different signalling pathways, associated pathologies, inflammatory mediators, pharmacological potential, current status, and challenges with anti-inflammatory drugs.

Effect of Simvastatin and Low-Level Laser Therapy on Sutural Bone Formation After Expansion in Rats: Biomechanical, Computed Tomography and Immunohistochemical Assessment

Introduction: The application of low-level laser therapy (LLLT) and some medications have been shown to accelerate bone formation in rapid palatal expansion (RPE). A combination of these two therapeutic modalities may reduce the time required for the retention period. This study sought to assess the effects of simvastatin and LLLT, alone and combined, on sutural bone formation in rats. Methods: Sixty male Wistar rats averagely weighing 150 g were divided into five groups (n=12) of control (group 1), 5 mg simvastatin (group 2), 10 mg simvastatin (group 3), LLLT (group 4), and LLLT plus 10 mg simvastatin (group 5). The expansion appliance was placed in the parietal bone in all groups. One week after placing the appliance, the spring was fixed with Duralay acrylic resin to serve as a retainer during the rest of the experiment. The rats were sacrificed after 30 (for biomechanical and computed tomography [CT] assessments) or 60 days (for biomechanical, CT and immunohistochemical [IHC] assessments). Results: Groups 3 and 4 showed a significant improvement in osteogenesis (confirmed by CT findings, histological analysis and biomechanical test) compared to the control group. Group 5 was significantly superior to all other groups in terms of all parameters (P<0.001). Group 2 and the control group were not significantly different (P>0.05). Conclusion: Although LLLT, simvastatin treatment and the combination of both significantly improved sutural bone formation in rats compared to the control group, the combined treatment showed significantly superior clinical results compared to other interventions.

Osteoporosis Entwined with Cardiovascular Disease: The Implication of Osteoprotegerin and the Example of Statins

Beyond being epiphenomenon of shared epidemiological factors, the integration of Osteoporosis (OP) with Cardiovascular Disease (CVD) - termed "calcification paradox" - reflects a continuum of aberrant cardiometabolic status. The present review provides background knowledge on "calcification paradox", focusing on the endocrine aspect of vasculature orchestrated by the osteoblastic molecular fingerprint of vascular cells, acquired via imbalance among established modulators of mineralization. Osteoprotegerin (OPG), the well-established osteoprotective cytokine, has recently been shown to exert a vessel-modifying role. Prompted by this notion, the present review interrogates OPG as the potential missing link between OP and CVD. However, so far, the confirmation of this hypothesis is hindered by the equivocal role of OPG in CVD, being both proatherosclerotic and antiatherosclerotic. Further research is needed to illuminate whether OPG could be a biomarker of the "calcification paradox". Moreover, the present review brings into prominence the dual role of statins - cardioprotective and osteoprotective - as a potential illustration of the integration of CVD with OP. Considering that the statins-induced modulation of OPG is central to the statins-driven osteoprotective signalling, statins could be suggested as an illustration of the role of OPG in the bone/vessels crosstalk, if further studies consolidate the contribution of OPG to the cardioprotective role of statins. Another outstanding issue that merits further evaluation is the inconsistency of the osteoprotective role of statins. Further understanding of the varying bone-modifying role of statins, likely attributed to the unique profile of different classes of statins defined by distinct physicochemical characteristics, may yield tangible benefits for treating simultaneously OP and CVD.

Thermoresponsive Hydrogel-Based Local Delivery of Simvastatin for the Treatment of Periodontitis

Except for routine scaling and root planing, there are few effective nonsurgical therapeutic interventions for periodontitis and associated alveolar bone loss. Simvastatin (SIM), one of the 3-hydroxy-3-methylglutaryl-cosenzyme A reductase inhibitors, which is known for its capacity as a lipid-lowering medication, has been proven to be an effective anti-inflammatory and bone anabolic agent that has shown promising benefits in mitigating periodontal bone loss. The local delivery of SIM into the periodontal pocket, however, has been challenging due to SIM's poor water solubility and its lack of osteotropicity. To overcome these issues, we report a novel SIM formulation of a thermoresponsive, osteotropic, injectable hydrogel (PF127) based on pyrophosphorolated pluronic F127 (F127-PPi). After mixing F127-PPi with F127 at a 1:1 ratio, the resulting PF127 was used to dissolve free SIM to generate the SIM-loaded formulation. The thermoresponsive hydrogel's rheologic behavior, erosion and SIM release kinetics, osteotropic property, and biocompatibility were evaluated in vitro. The therapeutic efficacy of SIM-loaded PF127 hydrogel on periodontal bone preservation and inflammation resolution was validated in a ligature-induced periodontitis rat model. Given that SIM is already an approved medication for hyperlipidemia, the data presented here support the translational potential of the SIM-loaded PF127 hydrogel for better clinical management of periodontitis and associated pathologies.

Statins repress hedgehog signaling in medulloblastoma with no bone toxicities

The Hedgehog (Hh) pathway plays an indispensable role in bone development and genetic activation of the pathway results in medulloblastoma (MB), the most common malignant brain tumor in children. Inhibitors of Hh pathway (such as vismodegib and sonedigib), which are used to treat MB, cause irreversible defects in bone growth in young children. Cholesterol is required for the activation of the Hh pathway, and statins, inhibitors of cholesterol biosynthesis, suppress MB growth by repressing Hh signaling in tumor cells. Here, we investigate the role of cholesterol biosynthesis in the proliferation and Hh signaling in chondrocytes, and examine the bone development in mice after statin treatment. Statins significantly inhibited MB growth in young mice, but caused no defects in bone development. Conditional deletion of NADP steroid dehydrogenase-like (NSDHL), an enzyme necessary for cholesterol biosynthesis, suppressed cholesterol synthesis in chondrocytes, and disrupted the growth plate in mouse femur and tibia, indicating the important function of intracellular cholesterol in bone development. Hh pathway activation and the proliferation of chondrocytes were inhibited by statin treatment in vitro; however, statins did not impair bone growth in vivo due to insufficient penetration into the bone. Our studies reveal a critical role of cholesterol in bone development, and support the utilization of statins for treatment of MB as well as other Hh pathway-associated malignancies.

Statins as a Therapeutic Approach for the Treatment of Pseudoxanthoma Elasticum Patients: Evaluation of the Spectrum Efficacy of Atorvastatin In Vitro

Pseudoxanthoma elasticum (PXE) is an autosomal recessive disorder caused by mutations in the ATP-binding cassette sub-family C member 6 gene. Our previous studies revealed that PXE might be associated with premature aging. Treatment with statins showed positive effects not only for PXE but also for other diseases associated with premature aging like Hutchinson–Gilford progeria syndrome. Nevertheless, the molecular mechanisms in the case of PXE remain unclear. Thus, this study was performed to evaluate the efficiency of atorvastatin by analyzing key characteristics of the PXE phenotype in primary human dermal fibroblasts of PXE patients. Our data indicate that an atorvastatin treatment has a positive effect, especially on factors associated with cholesterol biosynthesis and prenylation processes, whereas the effect on age- and calcification-related factors was less pronounced.

Effect of oral statin use on mitomycin-C augmented trabeculectomy outcomes

Purpose

The effect of statins on wound healing is controversial, and their effect on trabeculectomy outcomes remains unclear. This study aimed to examine the relationship between oral statin use and trabeculectomy outcomes.

Methods

Medical records of patients who underwent primary mitomycin-C augmented trabeculectomy with 2 years of follow-up were reviewed. Pre- and postoperative intraocular pressures (IOP) and numbers of medications, subconjunctival 5-fluorouracil (5-FU) injections, and bleb-needling procedures were compared between statin users and nonusers. Failure was defined as an eye that failed to achieve a 20% lowering of IOP from baseline or had an IOP > 21 mm Hg, as well as an eye that required further surgical intervention, developed hypotony, or had no light perception visual acuity.

Results

In total, 158 subjects were enrolled, with 47 eyes from statin users and 111 eyes from statin nonusers. The 24-month cumulative probability of failure was 78.7% for statin users and 60.4% for nonusers (P = .013). Cox proportional-hazards modeling showed a significantly higher hazard risk in statin users (adjusted hazard ratio 1.61, P = .026). There were no significant between-group differences in mean IOPs or number of medications (both P > .05) at 24 months. Multivariable Poisson regression analysis that statin use was associated with increased numbers of 5-FU injections (P = .014) and bleb-needling procedures (P = .031).

Conclusions

This study demonstrated that oral statin use was associated with higher rates of trabeculectomy failure and increased numbers of 5-FU injections and bleb-needling procedures.

Statins, bone biology and revision arthroplasty: review of clinical and experimental evidence

Osteoarthritis is a painful, disabling condition which is increasing in prevalence as a result of an ageing population. With no recognized disease-limiting therapeutics, arthroplasty of the hip and knee is the most common and effective treatment for lower limb osteoarthritis, however lower limb arthroplasty has a finite life-span and a proportion of patients will require revision arthroplasty. With increasing life expectancy and an increasing proportion of younger (<65 years) patients undergoing arthroplasty, the demand for revision arthroplasty after implant failure is also set to increase. Statins are cholesterol-modulating drugs widely used for cardiovascular risk reduction which have been noted to have pleiotropic effects including potentially influencing arthroplasty survival. In vitro studies have demonstrated pleiotropic effects in human bone cells, including enhancement of osteoblastogenesis following simvastatin exposure, and in vivo studies have demonstrated that intraperitoneal simvastatin can increase peri-implant bone growth in rats following titanium tibial implant insertion. There is evidence that statins may also influence osseointegration, enhancing bone growth at the bone-implant interface, subsequently improving the functional survival of implants. Data from the Danish Hip Arthroplasty Registry and the Clinical Practice Research Datalink in the UK suggest a reduction in the risk of lower limb revision arthroplasty in statin ever-users versus never-users, and a time-dependent effect of statins in reducing the risk of revision. In this article we review the clinical and experimental evidence linking statins and risk of revision arthroplasty.

Enhanced osteogenesis and therapy of osteoporosis using simvastatin loaded hybrid system

Postmenopausal osteoporosis is a common chronic dynamic bone disorder, caused by estrogen deficiency. To address this issue, we constructed a controlled drug-release system composed of poly (N-isopropylacrylamide) brush modified mesoporous hydroxyapatite (MHA-SIM-P) loaded with simvastatin (SIM) using an ovariectomised (OVX) rat model. Quantitative alkaline phosphatase activity assay, alizarin red staining and RT-PCR were tested to evaluate the osteogenic ability in vitro. The results showed that the MHA-SIM-P nanoparticles significantly improved the osteogenic differentiation of OVX bone marrow stromal cells (BMSCs) in vitro. In osteoporotic animal model, the therapeutic efficiency for bone defect was evaluated by μCT analysis, tartrate-resistant acid phosphatase, haematoxylin and eosin staining, which showed improved bone formation and less osteoclastic response in OVX rats after surgery for 3 and 6 weeks. This polymer brush modified MHA system provided a sustained release system of hydrophobic SIM to inhibit osteoporosis together with MHA nanoparticle promoting the osteogenesis. Thus, this novel strategy exhibited great potential for promoting osteogenic ability and treating local osteoporotic defects.

The effects of statins on dental and oral health: a review of preclinical and clinical studies

The statin family of drugs are safe and effective therapeutic agents for the treatment of arteriosclerotic cardiovascular disease (CVD). Due to a wide range of health benefits in addition to their cholesterol lowering properties, statins have recently attracted significant attention as a new treatment strategy for several conditions, which are not directly related to normalizing a lipid profile and preventing CVD. Statins exert a variety of beneficial effects on different aspects of oral health, which includes their positive effects on bone metabolism, their anti-inflammatory and antioxidant properties, and their potential effects on epithelization and wound healing. Additionally, they possess antimicrobial, antiviral, and fungicidal properties, which makes this class of drugs attractive to the field of periodontal diseases and oral and dental health. However, to the best of our knowledge, there has been no comprehensive study to date, which has investigated the effects of statin drugs on different aspects of dental and oral health. Therefore, the primary objective of this paper was to review the effect of statins on dental and oral health. Results of our extensive review have indicated that statins possess remarkable and promising effects on several aspects of dental and oral health including chronic periodontitis, alveolar bone loss due to either extraction or chronic periodontitis, osseointegration of implants, dental pulp cells, orthodontic tooth movement, and orthodontic relapse, tissue healing (wound/bone healing), salivary gland function, and finally, anti-cancer effects. Hence, statins can be considered as novel, safe, inexpensive, and widely-accessible therapeutic agents to improve different aspects of dental and oral health.

Adjuvant drug-assisted bone healing: Part III - Further strategies for local and systemic modulation

In this third in a series of reviews on adjuvant drug-assisted bone healing, further approaches aiming at influencing the healing process are discussed. Local and systemic modulation of bone metabolism is pursued with use of a number of drugs with completely different indications, which are characterized by a pleiotropic spectrum of action. These include drugs used to treat lipid disorders (HMG-CoA reductase inhibitors), hypertension (ACE inhibitors), osteoporosis (bisphosphonates), cancer (proteasome inhibitors) and others. Potential applications to enhance bone healing are discussed.

Effect of Simvastatin on Bone Regeneration: A Histologic and Histomorphometric Analysis

PURPOSE

The purpose of the present study was to evaluate the efficacy of simvastatin administration as an osteoinductive agent combined with bovine bone material (BBM) for augmentation of human maxillary sinuses.

MATERIALS AND METHODS

In the present randomized clinical trial with a split-mouth design, 24 maxillary sinuses in 12 patients were augmented using BBM alone or BBM combined with simvastatin. Biopsy samples were taken 9 months after maxillary sinus floor augmentation for histologic and histomorphometric analyses. A total of 44 implants were placed in the augmented bone.

RESULTS

The results of the microscopic assessment of most samples revealed no inflammation or only mild chronic inflammation. Lamellation was detectable in old bone trabeculae under polarized light microscopy but was not observed in newly formed bone. Osteocytes were found with a lower frequency in the lacunae of newly formed bone compared with normal bone. No significant differences were found in the amount of newly formed bone and the amount of residual particles between the 2 groups.

CONCLUSIONS

Despite the greater mean percentage of newly formed bone in the test group, the histomorphometric analysis results did not show a significant positive effect for the use of simvastatin in maxillary sinus augmentation.

Bone union formation in the rat mandibular symphysis using hydroxyapatite with or without simvastatin: effects on healthy, diabetic, and osteoporotic rats

OBJECTIVE

The objective is to compare new bone formation in critical defects in healthy, diabetic, and osteoporotic rats filled with hydroxyapatite (HA) alone and HA combined with simvastatin (SV).

MATERIALS AND METHODS

A total of 48 adult female Sprague-Dawley rats were randomized into three groups (n = 16 per group): Group, 1 healthy; Group 2, diabetics; and Group 3, osteoporotics. Streptozotocin was used to induce type 1 diabetes in Group 2, while bilateral ovariectomy was used to induce osteoporosis in Group 3. The central portion of the rat mandibular symphysis was used as a physiological critical bone defect. In each group, eight defects were filled with HA alone and eight with HA combined with SV. The animals were sacrificed at 4 and 8 weeks, and the mandibles were processed for micro-computed tomography to analyze radiological union and bone mineral density (BMD); histological analysis of the bone union; and immunohistochemical analysis, which included immunoreactivity of vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2).

RESULTS

In all groups (healthy, diabetics, and osteoporotics), the defects filled with HA + SV presented greater radiological bone union, BMD, histological bone union, and more VEGF and BMP-2 positivity, in comparison with bone defects treated with HA alone.

CONCLUSIONS

Combined application of HA and SV improves bone regeneration in mandibular critical bone defects compared with application of HA alone in healthy, diabetic, and osteoporotic rats.

CLINICAL RELEVANCE

This study might help to patients with osteoporosis or uncontrolled diabetes type 1, but future studies should be done.

The stimulatory impact of d-δ-Tocotrienol on the differentiation of murine MC3T3-E1 preosteoblasts

Osteoblasts and osteoclasts play essential and opposite roles in maintaining bone homeostasis. Osteoblasts fill cavities excavated by osteoclasts. The mevalonate pathway provides essential prenyl pyrophosphates for the activities of GTPases that promote differentiation of osteoclasts but suppress that of osteoblasts. Preclinical and clinical studies suggest that mevalonate suppressors such as statins increase bone mineral density and reduce risk of bone fracture. Tocotrienols down-regulate 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, the rate-limiting enzyme in the mevalonate pathway. In vivo studies have shown the bone-protective activity of tocotrienols. We hypothesize that d-δ-tocotrienol, a mevalonate suppressor, induces differentiation of murine MC3T3-E1 preosteoblasts. Alizarin staining showed that d-δ-tocotrienol (0-25 μmol/L) induced mineralized nodule formation in a concentration-dependent manner in MC3T3-E1 preosteoblasts. d-δ-Tocotrienol (0-25 μmol/L), but not D-α-tocopherol (25 μmol/L), significantly induced alkaline phosphatase activity, an indicator of preosteoblast differentiation. The expression of differentiation marker genes including BMP-2 and VEGFα was stimulated dose dependently by d-δ-tocotrienol (0-25 μmol/L). Concomitantly, Western blot analysis showed that d-δ-tocotrienol down-regulated HMG CoA reductase. d-δ-Tocotrienol (0-25 μmol/L) had no impact on the viability of MC3T3-E1 preosteoblasts following 48-h incubation, suggesting lack of cytotoxicity at these doses. Tocotrienols and other mevalonate suppressors have potential in maintaining bone health.

A Delphinidin-Enriched Maqui Berry Extract Improves Bone Metabolism and Protects against Bone Loss in Osteopenic Mouse Models

In our previous investigation, delphinidin, one of the most abundant anthocyanins found in vegetables and berry fruits, had been shown to inhibit osteoclasts and prevent bone loss in mouse models of osteoporosis. In the present study, we investigated whether a delphinidin glycoside-enriched maqui berry extract (MBE, Delphinol^®) exhibits beneficial effects on bone metabolism both in vitro and in vivo. MBE stimulated the osteoblastic differentiation of MC3T3-E1 cells, as indicated by enhanced mineralized nodule formation, and increased alkaline phosphatase activity, through the upregulation of bone morphogenetic protein 2 (Bmp2), runt-related transcription factor 2 (Runx2), osterix (Osx), osteocalcin (Ocn), and matrix extracellular phosphoglycoprotein (Mepe) mRNA expression. Immunostaining and immunoprecipitation assays demonstrated that MBE suppressed NF-κB transnucleation through acting as a superoxide anion/peroxynitrite scavenger in MC3T3-E1 cells. Simultaneously, MBE inhibited both osteoclastogenesis in primary bone marrow macrophages and pit formation by maturated osteoclasts on dentine slices. Microcomputed tomography (micro-CT) and bone histomorphometry analyses of femurs demonstrated that the daily ingestion of MBE significantly increased BV/TV (ratio of bone volume to tissue volume), Tb.Th (trabecular thickness), Tb.N (trabecular number), N.Nd/N.Tm (node to terminus ratio), OV/TV (ratio of osteoid volume to tissue volume), BFR/TV (bone formation rate per tissue volume), and significantly decreased Tb.Sp (trabecular separation), ES/BS (ratio of eroded surface to bone surface) and N.Oc/BS (number of osteoclast per unit of bone surface), compared to vehicle controls in osteopenic mouse models. These findings suggest that MBE can be a promising natural agent for the prevention of bone loss in osteopenic conditions by not only inhibiting bone resorption, but also stimulating bone formation.

Lovastatin increases the proliferation and osteoblastic differentiation of human gingiva-derived stem cells in three-dimensional cultures

Lovastatin is a cholesterol-lowering agent that also has effects of cell proliferation and apoptosis. The present study was performed to evaluate the effects of lovastatin on the proliferation and osteogenic differentiation of three-dimensional cell spheroids formed from human gingiva-derived stem cells (GDSCs) using concave microwells. GDSCs were plated on polydimethylsiloxane-based concave micromolds and grown in the presence of lovastatin at concentrations of 0, 2 and 6 µM. The morphology of the cells was viewed under an inverted microscope, and cell viability was determined with Cell Counting kit-8 on days 2, 7 and 14. Alkaline phosphatase activity assays were performed to evaluate the osteogenic differentiation on days 2 and 8. Alizarin red-S staining was also used to assess the mineralization of the stem cell spheroids at day 14. The results confirmed that GDSCs formed spheroids in concave microwells. No significant changes were noted with longer incubation time, and no significant differences in cell viability were noted between the three lovastatin groups at each time point. Higher osteogenic differentiation was observed in the 2 µM group when compared with the control. Mineralized extracellular deposits were visible after Alizarin red-S staining, and higher mineralization was noted in the 2 and 6 µM lovastatin groups when compared with the 0 µM control. The relative mineralization values of the 0, 2 and 6 µM groups on day 14 were 39.0±9.6, 69.3±6.0 and 60.9±7.5, respectively. This study demonstrated that the application of lovastatin enhanced the osteogenic differentiation of cell spheroids formed from GDSCs. This suggests that combinations of lovastatin and stem cell spheroids may have the potential for use in tissue engineering.

Injectable calcium phosphate foams for the delivery of Pitavastatin as osteogenic and angiogenic agent

Apatitic bone cements have been used as a clinical bone substitutes and drug delivery vehicles for therapeutic agents in orthopedic applications. This has led to their combination with different drugs with known ability to foster bone formation. Recent studies have evaluated Simvastatin for its role in enhanced bone regeneration, but its lipophilicity hampers incorporation and release to and from the bone graft. In this study, injectable calcium phosphate foams (i-CPF) based on α-tricalcium phosphate were loaded for the first time with Pitavastatin. The stability of the drug in different conditions relevant to this study, the effect of the drug on the i-CPFs properties, the release profile, and the in vitro biological performance with regard to mineralization and vascularization were investigated. Pitavastatin did not cause any changes in neither the micro nor the macro structure of the i-CPFs, which retained their biomimetic features. PITA-loaded i-CPFs showed a dose-dependent drug release, with early stage release kinetics clearly affected by the evolving microstructure due to the setting of cement. in vitro studies showed dose-dependent enhancement of mineralization and vascularization. Our findings contribute towards the design of controlled release with low drug dosing bone grafts: i-CPFs loaded with PITA as osteogenic and angiogenic agent.

Mimicking growth factors: role of small molecule scaffold additives in promoting tissue regeneration and repair

The primary aim of tissue engineering scaffolds is to mimic the in vivo environment and promote tissue growth. In this quest, a number of strategies have been developed such as enhancing cell-material interactions through modulation of scaffold physico-chemical parameters. However, more is required for scaffolds to relate to the cell natural environment. Growth factors (GFs) secreted by cells and extracellular matrix (ECM) are involved in both normal repair and abnormal remodeling. The direct use of GFs on their own or when incorporated within scaffolds represent a number of challenges such as release rate, stability and shelf-life. Small molecules have been proposed as promising alternatives to GFs as they are able to minimize or overcome many shortcomings of GFs, in particular immune response and instability. Despite the promise of small molecules in various TE applications, their direct use is limited by nonspecific adverse effects on non-target tissues and organs. Hence, they have been incorporated within scaffolds to localize their actions and control their release to target sites. However, scanty rationale is available which links the chemical structure of these molecules with their mode of action. We herewith review various small molecules either when used on their own or when incorporated within polymeric carriers/scaffolds for bone, cartilage, neural, adipose and skin tissue regeneration.

The impact of simvastatin intervention on the healing of bone, soft tissue, and TMJ cartilage in dentistry: a systematic review and meta-analysis

The review aimed at assessing the osteopromotive potential as well as soft tissue and temporomandibular joint (TMJ) cartilage healing properties of simvastatin by summarizing its efficacy on the current dental treatment of periodontal bone and soft tissue defects, and temporomandibular joint (TMJ) arthritis from the available animals and human studies. An electronic search was performed on MEDLINE, Scopus, and Cochrane Central Register of Controlled Trials (CENTRAL) using a combination of keywords. A hand search was undertaken on seven oral surgery journals. No limitation of publication year in the English language was placed. Controlled randomized animal and human clinical trials, as well as prospective comparative studies, were included. Data on the comparison of topical/systemic simvastatin on bone healing in intrabony and furcation defects, extraction sockets, distraction osteogenesis, as well as soft tissue healing in mucogingival grafting procedures and cartilage protection in TMJ arthritis were extracted from all the eligible studies. Studies with a minimum of ten participants and follow up at least 6 months were included. Ten animal studies and six clinical studies were included in this study. All the animal studies included a minimum of eight sites per group assessed clinically, histologically, and radiographically. All human studies included clinical and radiological evaluation. The results of the review show that simvastatin administration displays positive treatment outcomes in the full range of therapies investigated in the oral regions such as periodontal infection control, periodontal and alveolar bone regeneration, soft tissue grafting, TMJ inflammation reduction, and cartilage repair. Its mechanism includes stimulating bone formation, promoting soft tissue healing, increasing articular and condylar cartilage thickness, as well as reducing inflammation at surgical sites in TMJ disorders. Simvastatin administration is beneficial to the healing of oral bone and cartilage. More studies are desired to determine its potential in soft tissue healing.

Contribution of Statins towards Periodontal Treatment: A Review

The pleiotropic effects of statins have been evaluated to assess their potential benefit in the treatment of various inflammatory and immune-mediated diseases including periodontitis. Herein, the adjunctive use of statins in periodontal therapy in vitro, in vivo, and in clinical trials was reviewed. Statins act through several pathways to modulate inflammation, immune response, bone metabolism, and bacterial clearance. They control periodontal inflammation through inhibition of proinflammatory cytokines and promotion of anti-inflammatory and/or proresolution molecule release, mainly, through the ERK, MAPK, PI3-Akt, and NF-κB pathways. Moreover, they are able to modulate the host response activated by bacterial challenge, to prevent inflammation-mediated bone resorption and to promote bone formation. Furthermore, they reduce bacterial growth, disrupt bacterial membrane stability, and increase bacterial clearance, thus averting the exacerbation of infection. Local statin delivery as adjunct to both nonsurgical and surgical periodontal therapies results in better periodontal treatment outcomes compared to systemic delivery. Moreover, combination of statin therapy with other regenerative agents improves periodontal healing response. Therefore, statins could be proposed as a potential adjuvant to periodontal therapy. However, optimization of the combination of their dose, type, and carrier could be instrumental in achieving the best treatment response.

The sole and combined effect of simvastatin and platelet rich fibrin as a filling material in induced bone defect in tibia of albino rats

Statins like simvastatin (SIM) have demonstrated to have pleiotropic actions other than their conventional use as antilipidemic drugs. Also, nowadays natural scaffolds like platelets rich fibrin (PRF) showed promising results on bone regeneration. Aim This study compare the regenerative power of SIM and PRF added locally each as a sole filling material on induced bone defect and evaluate the combined effect using PRF loaded with SIM. MATERIALS AND METHODS: A critical size bone defect was induced in 48 male albino rats of average weight 150-200 g and were divided into 4 groups according to the filling material. Control, PRF, SIM, and SIM/PRF group. Each group was subdivided according to the sacrificing period into two subgroups (one and two-months postoperatively). Tibial specimens were evaluated histologically using masson trichrome (MT) special stain to detect areas of new bone formation, immunohistochemically using anti- BMP2 and anti-VEGF, serum levels of Osteoprotegerin (OPG), RANKL, osteocalcin and alkaline phosphatase enzyme (ALP) were measured one and two months postoperatively using ELISA, Finally bone mineral density (BMD) at the bone defect area was analyzed using digital X-ray one and two-months postoperatively. RESULTS: The percentage of newly formed bone increased significantly in the three groups vs the control group with the highest significant increase (p < 0.001) in the SIM/PRF group one month postoperatively. Also, SIM/PRF group was the only group which showed significant bone maturation two-months postoperatively compared to the other groups. Immunohistochemical analysis showed significant increase in positively stained BMP-2 and VEGF expression (p < 0.001) in the three groups vs the control group with the highest significant increase (p < 0.001) in the SIM/PRF group. Serum bone anabolic markers increased significantly in the SIM and SIM/PRF groups. In contrast, RANKL serum level decreased significantly in the SIM and SIM/PRF group one month postoperatively with no significant decrease in the PRF group vs the control group. Digital X-ray results revealed the highest BMD percent change was found in the SIM/PRF group and showed complete bone healing two-months postoperatively.

Graphene Family Materials in Bone Tissue Regeneration: Perspectives and Challenges

We have witnessed abundant breakthroughs in research on the bio-applications of graphene family materials in current years. Owing to their nanoscale size, large specific surface area, photoluminescence properties, and antibacterial activity, graphene family materials possess huge potential for bone tissue engineering, drug/gene delivery, and biological sensing/imaging applications. In this review, we retrospect recent progress and achievements in graphene research, as well as critically analyze and discuss the bio-safety and feasibility of various biomedical applications of graphene family materials for bone tissue regeneration.

Biometric, histomorphometric, and biochemical profile in atorvastatin calcium treatment of female rats with dexamethasone-induced osteoporosis

OBJECTIVE

To assess the effects of atorvastatin calcium in the treatment of dexamethasone-induced osteoporosis.

METHODS

Osteoporosis induction consisted of the administration of an intramuscular dose of 7.5 mg/kg of body weight of dexamethasone, once a week for four weeks, except for the control animals (G1). The animals were divided into the following groups: G1 (control group without osteoporosis), G2 (control group with untreated osteoporosis), G3 (control group with osteoporosis treated with sodium alendronate 0.2 mg/kg) and G4 (group with osteoporosis treated with atorvastatin calcium 1.2 mg/kg). Serum alkaline phosphatase, bone alkaline phosphatase, and biometric and bone histomorphometric assessments were performed after 30 and 60 days of treatment onset.

RESULTS

In relation to the biometric and histomorphometric analyses, at 60 days of treatment, G4 presented bone density (Seedor index), bone trabecular density, and cortical thickness of 0.222 ± 0.004 g/cm, 59.167 ± 2.401%, and 387,501 ± 8573 μm, respectively, with a positive and statistically significant difference (p < 0.05), in relation to G2. At 30 and 60 days of treatment, G4 presented statistically significant serum levels of alkaline phosphatase alkaline phosphatase (p < 0.05) that were higher than all groups (7.451 ± 0.173 μg/L and 7.473 ± 0.529 μg/L, respectively).

CONCLUSION

Treatment with atorvastatin calcium demonstrated the ability of this drug to increase osteoblastic activity and bone tissue repair activity, acting differently from alendronate sodium, which demonstrated predominantly antirebsorptive activity.

The effect of local and systemic statin use as an adjunct to non-surgical and surgical periodontal therapy-A systematic review and meta-analysis

OBJECTIVES

To evaluate the effect of local and/or systemic statin use as an adjunct to non-surgical and/or surgical periodontal therapy.

DATA

Literature search according to PRISMA guidelines with the following eligibility criteria: (a) English or German language; (b) interventional studies; (c) statins as monotherapy or as an adjunct to non-surgical and/or surgical treatment of periodontitis; (d) clinical and/or radiographic treatment effect size of statin intake reported.

SOURCES

Medline (PubMed), Embase (Ovid), CENTRAL (Ovid).

STUDY SELECTION

Thirteen clinical studies regarding local application and 2 with systemic administration of statins as an adjunct to non-surgical treatment (SRP) and 4 studies regarding intrasurgical statin application with a maximum follow-up of 9 months could be included; simvastatin, atorvastatin, and rosuvastatin were used. Local but not systemic statin application as an adjunct to SRP yielded significantly larger probing pocket depth (PD), radiographic defect depth (RDD), and bleeding index reduction, and larger clinical attachment level gain, and less residual PD and RDD (p≤0.016); rosuvastatin appeared as the most efficacious. Three of 4 studies reported a significant positive effect of intrasurgical statin application. No adverse events were reported after statin use. The vast majority of the included studies were from the same research group.

CONCLUSIONS

Significant additional clinical and radiographic improvements are obtained after local, but not systemic, statin use as an adjunct to SRP in deep pockets associated with intrabony defects and seemingly with furcation defects; intrasurgical statin application seems similarly beneficial. Confirmation of these results, and especially of the effect size, from other research groups is warranted.

Evaluation of the Efficacy of Simvastatin in Bone Regeneration after Surgical Removal of Bilaterally Impacted Third Molars-A Split-Mouth Randomized Clinical Trial

PURPOSE

Simvastatin has been reported to promote osteoblastic activity, inhibit osteoclastic activity, and support osteoblast differentiation induced by bone morphogenetic protein. This split-mouth randomized clinical trial evaluated the effect of local application of simvastatin (10 mg) on bone regeneration after surgical removal of bilaterally impacted mandibular third molars.

MATERIALS AND METHODS

A randomized, split-mouth, single-blinded, single-center trial was performed in 30 patients 18 to 40 years old requiring surgical extraction of bilaterally impacted mandibular third molars. These patients underwent 2 surgical sessions, with extraction of 1 third molar during each session. Each participant was randomly assigned to receive Gelfoam soaked with normal saline or with the drug simvastatin (10 mg) at the first session and were blinded to the use of drug for that particular socket. The alternate regimen was used during the second session. The study was conducted over a period of 3 months. Patients were evaluated for pain, postoperative swelling, and bone density measurement and analysis using intraoral periapical radiographs at the end of 1, 4, 8 and 12 weeks, respectively. In addition, cone-beam computed tomographic (CBCT) images were obtained for every fifth patient at the end of 12 weeks.

RESULTS

Mean gray-level histographic values were significantly higher for the study sockets at the end of 1, 4, 8, and 12 weeks (P = .001) compared with the control sockets (30 sockets each). CBCT analysis further substantiated accelerated bone regeneration in the study sockets.

CONCLUSION

The study was statistically and radiographically in favor of the drug, indicating that local application of simvastatin could be a cost-effective and simple way to stimulate and hasten osseous regeneration.

KRAS-mutation status dependent effect of zoledronic acid in human non-small cell cancer preclinical models

Background

In non-small cell lung cancer (NSCLC) KRAS-mutant status is a negative prognostic and predictive factor. Nitrogen-containing bisphosphonates inhibit prenylation of small G-proteins (e.g. Ras, Rac, Rho) and thus may affect proliferation and migration. In our preclinical work, we investigated the effect of an aminobisphosphonate compound (zoledronic acid) on mutant and wild type KRAS-expressing human NSCLC cell lines.

Results

We confirmed that zoledronic acid was unable to inhibit the prenylation of mutant K-Ras unlike in the case of wild type K-Ras. In case of in vitro proliferation, the KRAS-mutant human NSCLC cell lines showed resistance to zoledronic acid wild-type KRAS-cells proved to be sensitive. Combinatory application of zoledronic acid enhanced the cytostatic effect of cisplatin. Zoledronic acid did not induce significant apoptosis. In xenograft model, zoledronic acid significantly reduced the weight of wild type KRAS-EGFR-expressing xenograft tumor by decreasing the proliferative capacity. Futhermore, zoledronic acid induced VEGF expression and improved in vivo tumor vascularization.

Materials and methods

Membrane association of K-Ras was examined by Western-blot. In vitro cell viability, apoptotic cell death and migration were measured in NSCLC lines with different molecular background. The in vivo effect of zoledronic acid was investigated in a SCID mouse subcutaneous xenograft model.

Conclusions

The in vitro and in vivo inhibitory effect of zoledronic acid was based on the blockade of cell cycle in wild type KRAS-expressing human NSCLC cells. The zoledronic acid induced vascularization supported in vivo cytostatic effect. Our preclinical investigation suggests that patients with wild type KRAS-expressing NSCLC could potentially benefit from aminobisphosphonate therapy.

Maxillary sinus lift using osteoinductive simvastatin combined with β-TCP versus β-TCP - a comparative pilot study to evaluate simvastatin enhanced and accelerated bone formation

PURPOSE

The aim of this study was to evaluate available bone quality and quantity after performing sinus augmentation using simvastatin/β-TCP combination versus β-TCP alone.

MATERIALS AND METHODS

This study included eight sinus lift procedures conducted on six patients. The sinuses were divided into two equal groups. The patients were recalled one, two weeks two, five, nine months post-operatively for post-operative evaluation. Radiographic evaluation involved cone beam computed tomography (CBCT) radiographs taken for every patient one week and nine months post-operatively to evaluate the changes in bone height, while histomorphometric evaluation involved transcortical bone biopsies taken after nine months during the second-stage surgery for implant placement.

RESULTS

The histomorphometric results showed that the amount of newly formed bone was higher in the simvastatin group when compared to the β-TCP group nine months after the surgery; the difference between the two groups was statistically significant. On the other hand, the radiographic evaluation showed that the rate of resorption of the simvastatin group was found to be higher than the control group; however, the difference between both groups was statistically insignificant.

CONCLUSION

These results showed that Simvastatin is safe to be used in sinus lift with promising osteoinductive capacity, yet further studies using larger sample size is needed.

The Effect of Strontium Ranelate Gel on Bone Formation in Calvarial Critical Size Defects

AIM:

The current study was designed to investigate the effectiveness of locally applied Strontium ranelate to induce bone formation.

MATERIALS AND METHODS:

Forty-eight female rats were divided into six groups (eight rats in each group): The three test groups included Strontium (SR) 2.5 mg, 5 mg and 10 mg that was dissolved in methylcellulose gel. The control groups included methylcellulose, simvastatin 5 mg and a negative control where the defect was left to heal without any intervention. At 44 days the groups were sacrificed, and the bone defects were assessed histomorphometically to assess bone formation. The data was statistically analysed.

RESULTS:

There was a statistically significant difference in the amount of new bone formation between all groups, where the 2.5 mg SR group showed the highest median bone percentage, is 41.95 %, followed by the 5, and 10 mg SR demonstrating a median bone are a percentage of 39.89%, and 30.19% respectively. Simvastatin showed a median bone percentage of 36.07 %, while the methylcellulose and the negative control groups demonstrated the lowest median area percentage of 23.12 and 20.70 % respectively.

CONCLUSIONS:

The study showed that the local application of an SR could up-regulate the bone formation and may prove to be a cost-effective method of bone regeneration.

Statins in nonsurgical and surgical periodontal therapy. A systematic review and meta-analysis of preclinical in vivo trials

The cholesterol-lowering drugs, statins, possess anti-inflammatory, antimicrobial and pro-osteogenic properties, and thus have been tested as an adjunct to periodontal treatment. The present systematic review aimed to answer the following focused research question: What is the effect of local and/or systemic statin use on periodontal tissues in preclinical in vivo studies of experimentally induced periodontitis (EIP) and/or acute/chronified periodontal defect (ACP) models? A literature search (of Medline/PubMed, Embase/Ovid, CENTRAL/Ovid) using the following main eligibility criteria was performed: (i) English or German language; (ii) controlled preclinical in vivo trials; (iii) local and/or systemic statin use in EIP and/or ACP models; and (iv) quantitative evaluation of periodontal tissues (i.e., alveolar bone level/amount, attachment level, cementum formation, periodontal ligament formation). Sixteen studies in EIP models and 7 studies in ACP models evaluated simvastatin, atorvastatin or rosuvastatin. Thirteen of the EIP (81%) and 2 of the ACP (29%) studies presented significantly better results in terms of alveolar bone level/amount in favor of statins. Meta-analysis based on 14 EIP trials confirmed a significant benefit of local and systemic statin use (P < .001) in terms of alveolar bone level/amount; meta-regression revealed that statin type exhibited a significant effect (P = .014) in favor of atorvastatin. Three studies reported a significantly higher periodontal attachment level in favor of statin use (P < .001). Complete periodontal regeneration was never observed; furthermore, statins did not exert any apparent effect on cementum formation. Neither local nor systemic use of statins resulted in severe adverse effects. Statin use in periodontal indications has a positive effect on periodontal tissue parameters, supporting the positive results already observed in clinical trials. Nevertheless, not all statins available have been tested so far, and further research is needed to identify the maximum effective concentration/dose and optimal carrier.

Does the adjunctive use of statins provide additional benefits to nonsurgical periodontal treatment? A systematic review and meta-analysis

Adjunctive therapeutic agents may be used to improve the response to nonsurgical periodontal therapy. Local delivery of statins (simvastatin, artovastatin and rosuvastatin) is a promising adjunct to scaling and root planing (SRP). Thus, the aim of this review is to evaluate if adjunctive local delivery of statins is more effective than SRP alone. Randomized clinical trials that presented a test group evaluating local delivery of statins as adjuncts in healthy, diabetic and smoking patients were included. Medline and the Cochrane library database were searched up to November 2016. Random effects meta-analyses were conducted for pocket depth change and clinical attachment gain. One hundred and twenty-five studies potentially related to the aim of this review were screened, but only 10 were included. The majority of the trials reported additional clinical benefits in the groups that were treated with adjunctive local delivery of statins. Pooled calculations showed that local delivery of statins resulted in additional reduction of pocket depth and clinical attachment gain in healthy people, smokers and diabetic patients. Local statins may offer additional clinical benefits to SRP, even in smokers and diabetics.

Locally Applied Simvastatin Promotes Bone Formation in a Rat Model of Spinal Fusion

Simvastatin, an inexpensive lipid-lowering drug widely used to prevent cardiovascular disorders, is known to increase osteoblastic activity, inhibit osteoclastic activity, and stimulate osteoblastic production of bone morphogenetic protein 2. Furthermore, local simvastatin application increased bone formation in animal models of fracture or bone defects. We investigated the effect of locally applied simvastatin in a rat model of spinal fusion. We performed posterolateral lumbar fusion surgery with iliac crest autograft in 36 rats divided into group I (n = 17; implanted with a gelatin scaffold) and group II (n = 19; implanted with a gelatin scaffold infused with 0.5 mg simvastatin). The rats were euthanized at 6 or 12 weeks postoperatively, and the spines were explanted and assessed. The fusion rates in group II (16.7%: 6 weeks, 30%: 12 weeks) were considerably higher than those in groups I (0%: 6 weeks, 0%: 12 weeks). The 6- and 12-week radiographic scores were significantly higher in group II than in group I. High-resolution micro-computerized tomography revealed that the tissue and bone volumes of the callus tended to be higher in group II than in group I. Histologic analysis of the spines explanted after 12 weeks demonstrated new bone formation between the transverse processes in group II, but thicker and wider individual trabeculae with fibrotic tissue and muscle fiber between the transverse processes in group I. Locally applied simvastatin was efficacious in accelerating bone formation in our rat model of spinal fusion, supporting its potential clinical application as a promoter of bone morphogenesis in spinal fusion. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1942-1948, 2017.

Atorvastatin, a double weapon in osteoporosis treatment: an experimental and clinical study

Objective

The aim of this study was to evaluate the effect of atorvastatin on the bone formation and resorption markers in ovariectomized rats (experimental study), and to study its effect on the bone mineral density (BMD) in postmenopausal osteoporotic women (clinical study).

Materials and methods

The study involved experimental and clinical aspects. In the experimental aspect, 42 female Wistar rats were divided into five groups: Group I (n=6; sham-operated), Group II (n=6; 1 mL of carboxymethyl cellulose [CMC] was administered orally), Group III (n=6; 20 mg/kg orally of atorvastatin was administered), Group IV (n=12; untreated ovariectomized [OVX] rats and served as a model of osteoporosis [OP]) and Group V (n=12; 20 mg/kg orally of atorvastatin was administered to ovariectomized rats). After 4 weeks, serum acid phosphatase, alkaline phosphatase, osteocalcin, total calcium and inorganic phosphorus were assessed. Then, 3 µm thickness lumbar and femur sections were examined using a light microscope to assess cortical thickness, trabecular area, numbers of osteoblasts and osteoclasts. In the clinical aspect, 85 post-menopausal osteoporotic females with recently detected hyperlipidemia participated in the study. Atorvastatin 40 mg/day, calcium carbonate 500 mg/day and vitamin D 800 international units were given to all patients for a period of 18 months. BMD was measured at the start and at the end of the study by dual-energy X-ray absorptiometry (DEXA).

Results

In the experiment aspect, the biomarkers of bone remodeling were notably elevated in the OVX group. Administration of atorvastatin produced a significant decrease in the level of these bone metabolic markers. Atorvastatin significantly ameliorates osteoporotic changes induced by ovariectomy. In the clinical aspect, after 18 months the DEXA showed improvement in the T-score for the three measured zones; however, these changes were statistically significant only in the femoral neck area.

Conclusion

Atorvastatin was able to decrease the rate of bone metabolism and increase osteogenic activity. It has dual mode of action; both anabolic and antiresorptive effect on bone. This lipophilic statin member may act as a double weapon drug.

Healing of extraction socket following local application of simvastatin: A split mouth prospective study

BACKGROUND

The role of simvastatin in lowering serum cholesterol level is well described. However, recent findings suggest they have a role in bone formation as well.

AIM AND OBJECTIVES

The present prospective study was conducted to evaluate the efficacy of simvastatin on bone formation in extraction sockets.

MATERIALS AND METHODS

15 patients undergoing all four first premolar extraction were selected based on inclusion and exclusion criteria. Extraction sockets of left premolars (24 and 34) were considered as cases and right premolars (14 and 44) as controls. Overall 30 extraction sites were assigned to each group. Atraumatic extraction was done in all cases following which simvastatin mixed with gelatin sponge was placed in extraction socket of 24 and 34 while only gelatin sponge was placed in 14 and 44. All sockets were then closed with 3-0 vicryl. The patients were kept on follow-up and complications such as dry socket, pain, and swelling were recorded. Intra oral peri apical radiographs were taken immediately after extraction and at 2nd month and 4th month to record changes in the density of alveolar bone. The radiographic measurements were compared and the differences were statistically analyzed.

RESULT

Percent increase in bone density at the end of 8th week and 16th week was significantly high in case as compared to the control group.

CONCLUSION

Local application of simvastatin induces bone formation in extraction sockets. Application is very simple and provides a very cost effective way of faster bone regeneration following tooth extraction.

Comparative evaluation of efficacy of subgingivally delivered 1.2% Atorvastatin and 1.2% Simvastatin in the treatment of intrabony defects in chronic periodontitis: a randomized controlled trial

Background. Statins are the recently evolved agents that aid in periodontal regeneration and ultimately in attaining periodontal health. Atorvastatin (ATV) and Simvastatin (SMV) are specific competitive inhibitors of 3-hydroxy-2-methyl-glutaryl coenzyme A reductase. The current study was conducted to compare the effectiveness of 1.2% ATV and 1.2% SMV, in addition to scaling and root planing (SRP), in the treatment of intrabony defects in subjects with chronic periodontitis. Methods. Ninety-six individuals were categorized into three treatment groups: SRP plus 1.2% ATV, SRP plus 1.2% SMV and SRP plus placebo. Clinical parameters of full-mouth plaque index (PI), modified sulcus bleeding index (mSBI), probing depth (PD), and relative attachment level (RAL) were recorded at baseline before SRP and at 3, 6 and 9 months. Bone fill was assessed using percentage radiographic defect depth reduction at baseline, 6 months and 9 months. Results. Both ATV and SMV showed significant PD reduction and RAL gain than placebo. ATV group showed greater mean PD reduction and mean RAL gain as compared to SMV group at 3, 6 and 9 months. Furthermore, ATV group sites exhibited a significantly greater percentage of radiographic defect depth reduction (33.23 ± 3.11%; 34.84 ± 3.07%) as compared to SMV (30.39 ± 3.36%; 32.15 ± 3.37%) at 6 and 9 months. Conclusion. ATV resulted in greater improvements in clinical parameters with higher percentage of radiographic defect depth reduction as compared to SMV in the treatment of intrabony defects in CP subjects.

Effects of Ankaferd BloodStopper on bone healing in an ovariectomized osteoporotic rat model

Bone defects resulting from oncological surgical resections, congenital facial anomalies, trauma or infection represent a significant and common clinical problem. The present study aimed to evaluate the effects of a commercially-available medicinal plant extract product, Ankaferd BloodStopper (ABS), on bone healing. The present study was performed on 24 female ovariectomized (OVX) rats. A defect on each rat calvarium was created using a trephine burr prior to the rats being divided into two groups. Defects were grafted with a gelatin sponge soaked with normal saline (control group) or plant extract (experimental group). Half of the animals were sacrificed after 2 weeks and the others after 4 weeks. In the control group, the defects were not filled with regenerated bone. By contrast, in the experimental group, all defect areas had an increased amount of regenerated bone and connective tissue. Osteoblastic activity appeared to be greater in the experimental group however, osteoclastic activity was observed to be higher in the control group. At 2 and 4 weeks, there was a significant difference in the amount of newly regenerated bone observed in the experimental group compared with the control group (P<0.05). Therefore, the results of the present study indicated that local ABS application had a positive effect on bone healing in the OVX rat model.

Effect of simvastatin on osteogenesis of the lumbar vertebrae in ovariectomized rats

The aim of the present study was to assess the role of simvastatin on osteoporosis of the vertebrae by examining the effect of simvastatin on the osteogenesis of the lumbar vertebra in ovariectomized (OVX) rats. A total of 60 6-month-old female Sprague Dawley rats were divided into one sham group and five ovariectomized groups, consisting of four simvastatin groups and one control group. Four dosages of simvastatin (5, 10, 20 and 40 mg/kg/d) were administered by gavage for three months. L4 vertebrae were examined by dual-energy X-ray absorptiometry (DEXA) and peripheral quantitative computed tomography (pQCT) to determine the mineral apposition rate (MAR). L5 vertebrae were examined using a compression biomechanical test. Although the measurements from DEXA, pQCT and MAR, and the biomechanical parameters in the OVX + simvastatin rats were higher than those for the OVX + vehicle group, no significant differences were detected. Therefore, simvastatin may not improve osteogenesis of the lumbar vertebra in OVX rats or prevent osteoporosis of the spinal vertebrae.

The roles of vascular endothelial growth factor in bone repair and regeneration

Vascular endothelial growth factor-A (VEGF) is one of the most important growth factors for regulation of vascular development and angiogenesis. Since bone is a highly vascularized organ and angiogenesis plays an important role in osteogenesis, VEGF also influences skeletal development and postnatal bone repair. Compromised bone repair and regeneration in many patients can be attributed to impaired blood supply; thus, modulation of VEGF levels in bones represents a potential strategy for treating compromised bone repair and improving bone regeneration. This review (i) summarizes the roles of VEGF at different stages of bone repair, including the phases of inflammation, endochondral ossification, intramembranous ossification during callus formation and bone remodeling; (ii) discusses different mechanisms underlying the effects of VEGF on osteoblast function, including paracrine, autocrine and intracrine signaling during bone repair; (iii) summarizes the role of VEGF in the bone regenerative procedure, distraction osteogenesis; and (iv) reviews evidence for the effects of VEGF in the context of repair and regeneration techniques involving the use of scaffolds, skeletal stem cells and growth factors.