Significant Osteogenic Potential Research Articles

Osteo-modulatory potential of biologically synthesized cis-resveratrol passivated gold nanoparticles

Resveratrol, a stilbene, particularly trans-isomer, shows significant osteogenic potential but experiences high instability and poor bioavailability. However, cis-isomer (cRes) is not explored yet due to its instability. Our study investigates the osteoinductive potential of cRes for the first time by stabilizing it onto the surface of gold nanoparticles. cRes capped GNPs (cRGNPs) presented no toxic effects on the MC3T3-E1 cells with increased levels of alkaline phosphatase and calcium deposition. The nanoparticles presented a 2.6-fold increase in cell number compared to the control. The pro-migratory effect of the cRGNPs was also significantly higher (97.21 ± 0.99 % migration) in 4 days. The osteoinductivity was further confirmed by enhanced expression of osteoblastic genes like RUNX2, OPN, OCN, BMP, OPG, and Col1A. The stability provided to cRes upon conjugating to GNPs allowed exploration of its potential in aiding proliferation, migration, and differentiation of the pre-osteoblasts, which will be beneficial in repairing bone defects.

Leptin attenuates the osteogenic induction potential of BMP9 by increasing β-catenin malonylation modification via Sirt5 down-regulation.

BMP9 has demonstrated significant osteogenic potential. In this study, we investigated the effect of Leptin on BMP9-induced osteogenic differentiation. Firstly, we found Leptin was decreased during BMP9-induced osteogenic differentiation and serum Leptin concentrations were increased in the ovariectomized (OVX) rats. Both in vitro and in vivo, exogenous expression of Leptin inhibited the process of osteogenic differentiation, whereas silencing Leptin enhanced. Exogenous Leptin could increase the malonylation of β-catenin. However, BMP9 could increase the level of Sirt5 and subsequently decrease the malonylation of β-catenin; the BMP9-induced osteogenic differentiation was inhibited by silencing Sirt5. These data suggested that Leptin can inhibit the BMP9-induced osteogenic differentiation, which may be mediated through reducing the activity of Wnt/β-catenin signalling via down-regulating Sirt5 to increase the malonylation level of β-catenin partly.

Laser-assisted synthesis of nano-hydroxyapatite and functionalization with bone active molecules for bone regeneration

The main goal of bone tissue engineering research is to replace the allogenic and autologous bone graft substitutes that can promote bone repair. Owing to excellent biocompatibility and osteoconductivity, hydroxyapatite is in extensive research and high demand for both medical and non-medical applications. Although various methods have been developed for the synthesis of hydroxyapatite, in the present study we have shown the use of nanosecond laser energy in the wet precipitation method of nano-hydroxyapatite (nHAP) synthesis without using ammonium solution or any other chemicals for pH maintenance. Here, the present study aimed to fabricate the nanohydroxyapatite using a nanosecond laser. The X-ray diffraction and Fourier transform infrared spectroscopy have confirmed the hydroxyapatite formation under laser irradiation in less time without aging. A transmission electron microscopy confirmed the nano size of synthesized nHAP, which is comparable to conventional nHAP. The length and width of the laser-assisted nHAP were found to be in the range of 50–200 nm and 15–20 nm, respectively, at various laser parameters. The crystallite size obtained by Debye Scherrer formulae was found to be in the range of ∼ 16–36 nm. In addition, laser-assisted nHAP based composite cryogel (nanohydroxyapatite/gelatin/collagen I) was synthesized and impregnated with bioactive molecules (bone morphogenic protein and zoledronic acid) that demonstrated significant osteogenic potential both in vitro in cell experiment and in vivo rat muscle pouch model (abdomen and tibia muscles). Dual-energy X-ray analysis, micro-CT, and histological analysis confirmed ectopic bone regeneration. Micro-CT based histomorphometry showed a higher amount (more than 10-fold) of mineralization for animal groups implanted with composite cryogels loaded with bioactive molecules compared to only composite cryogels groups. Our findings thus demonstrate a controlled and rapid synthetic method for the synthesis of nHAP with various physical, chemical, and biological properties exhibited as comparable to conventionally synthesized nHAP.

Calcined Hydroxyapatite with Collagen I Foam Promotes Human MSC Osteogenic Differentiation

Collagen I-based foams were modified with calcined or noncalcined hydroxyapatite or calcium phosphates with various particle sizes and pores to monitor their effect on cell interactions. The resulting scaffolds thus differed in grain size, changing from nanoscale to microscopic, and possessed diverse morphological characteristics and resorbability. The materials’ biological action was shown on human bone marrow MSCs. Scaffold morphology was identified by SEM. Using viability test, qPCR, and immunohistochemical staining, we evaluated the biological activity of all of the materials. This study revealed that the most suitable scaffold composition for osteogenesis induction is collagen I foam with calcined hydroxyapatite with a pore size of 360 ± 130 µm and mean particle size of 0.130 µm. The expression of osteogenic markers RunX2 and ColI mRNA was promoted, and a strong synthesis of extracellular protein osteocalcin was observed. ColI/calcined HAP scaffold showed significant osteogenic potential, and can be easily manipulated and tailored to the defect size, which gives it great potential for bone tissue engineering applications.

Osteogenic and chondrogenic differentiation potential of mesenchymal stem cells obtained from the bone marrow and placenta

Mesenchymal stem cells (MSC) represent a perspective resource for cell biotechnology. However the question of chondrogenic and osteogenic capacity of MSC of different origin remains under study.The aim of this study was to analyze the osteo-chondrogenic differentiation potential of MSC obtained from the bone marrow and placenta. The results of our studies have indicated that bone marrow-derived and placenta-derived MSC showed a chondrogenic potential in vitro after a chondrogenic induction with specific differentiation media. But for bone marrowderived MSC, the chondrogenic program was realized by expression of collagens (Coll2, Coll10), while in placenta-derived MSC cultures we found a progressive increase in COMP and Ver expression, so bone marrow-derived MSC is more preferable for use in cartilage tissue engineering. Regarding the results on alkaline phosphatase and alizarin red staining, bone marrowderived MSC showed a more significant osteogenic potential compared to placenta-derived MSC. Bone marrow-derived MSC in the composition of fibrin gel after osteogenic induction on the 14th day exhibited the activity of alkaline phosphatase, calcium depositions inside the cells and extracellular matrix, the increase in Sp7 and DMP expression.

Metal-based nanoparticles for bone tissue engineering.

Tissue is vital to the organization of multicellular organisms, because it creates the different organs and provides the main scaffold for body shape. The quest for effective methods to allow tissue regeneration and create scaffolds for new tissue growth has intensified in recent years. Tissue engineering has recently used some promising alternatives to existing conventional scaffold materials, many of which have been derived from nanotechnology. One important example of these is metal nanoparticles. The purpose of this review is to cover novel tissue engineering methods, paying special attention to those based on the use of metal-based nanoparticles. The unique physiochemical properties of metal nanoparticles, such as antibacterial effects, shape memory phenomenon, low cytotoxicity, stimulation of the proliferation process, good mechanical and tensile strength, acceptable biocompatibility, significant osteogenic potential, and ability to regulate cell growth pathways, suggest that they can perform as novel types of scaffolds for bone tissue engineering. The basic principles of various nanoparticle-based composites and scaffolds are discussed in this review. The merits and demerits of these particles are critically discussed, and their importance in bone tissue engineering is highlighted.

Recent Research Advances in Biologic Bone Graft Materials for Spine Surgery.

Biologic bone graft materials continue to be an important component of various spinal fusion procedures. Given the known risks and morbidity of harvesting iliac crest bone graft, the historical gold standard for spinal fusion, these biologic materials serve the purpose of improving both the efficacy and safety of spinal fusion procedures. Recent advances in biomedical and materials sciences have enabled the design of many novel materials that have shown promise as effective bone graft materials. This review will discuss current research pertaining to several of these materials, including functionalized peptide amphiphiles and other nanocomposites, novel demineralized bone matrix applications, 3D-printed materials, and Hyperelastic Bone®, among others. Recent investigation has demonstrated that novel technologies, including nanotechnology and 3D printing, can be used to produce biomaterials with significant osteogenic potential. Notably, peptide amphiphile nanomaterials functionalized to bind BMP-2 have demonstrated significant bone regenerative capacity in a pre-clinical rodent posterolateral lumbar fusion (PLF) model. Additionally, 3D-printed Hyperelastic Bone® has demonstrated promising bone regenerative capacity in several in vivo animal models. Composite materials such as TrioMatrix® (demineralized bone matrix, hydroxyapatite, and nanofiber-based collagen scaffold) have also demonstrated significant osteogenic potential in both in vitro and in vivo settings. Advances in materials science and engineering have allowed for the design and implementation of several novel biologic materials, including nanocomposites, 3D-printed materials, and various biologic composites. These materials provide significant bone regenerative capacity and have the potential to be alternatives to other bone graft materials, such as autograft and BMP-2, which have known complications.

Facial cortical bone regeneration post-extraction in non-grafted sockets allows for early implant placement and long-term functional stability

ObjectiveTo evaluate posterior implant placement feasibility shortly after tooth extraction in non-grafted sockets with and without dehiscence at the time of extraction. DesignNinety-five patients requiring posterior extractions entered this cross-sectional study. They were divided in three groups after extraction: G1 without dehiscence, G2 with dehiscence ≤5 and G3 > 5 mm. CBCT were taken prior to implant placement at an average of 12-weeks post-extraction to evaluate the need for grafting, cortical bone formation and bucco-lingual width (BLW). Actual BLW (n = 60) were compared to minimum expected BLW in 3 scenarios of BLW thickness averaging 6.4–7.4–8.4 mm. Peri-implant tissues were assessed for pocket formation and inflammation following established success criteria. ResultsNew cortical bone formation and sufficient BLW made implant placement feasible in sites with and without dehiscence at the time of extraction after an average healing time of 11.9 ± 2.4weeks (range: 8–18). Total average CBCT BLW was 10.1 ± 1.6 mm. All groups had a significantly higher BLW, than scenarios 1–3 (p < 0.0001). Molars were 20 times more likely than premolars to heal with BLW>10 mm (OR = 20; RR = 4.2; CI95 %: 5.3–74.2; p < 0.0001). Dehiscence sockets were 1.5 times more likely than non-dehiscenced sockets to present BLW ≤ 10 mm (OR = 1.5; RR = 0.6; CI95 %:0.9–2.5; p = 0.08). A band of keratinized tissue was present in all implants and success rates were 100 % at an average follow-up of 51.0 ± 23.4 months. ConclusionImplant placement is feasible without socket grafting shortly after tooth extraction. Non-grafted sockets present a significant osteogenic potential. Dehiscence sockets are likely to self-repair by forming a new cortical plate. The unassisted regenerated intra-socket bone allows for functional implant stability long-term.

Biocompatibility and Osteogenic Capacity of Mg-Zn-Ca Bulk Metallic Glass for Rabbit Tendon-Bone Interference Fixation.

Mg-based alloys have great potential for development into fixation implants because of their highly biocompatible and biodegradable metallic properties. In this study, we sought to determine the biocompatibility of Mg60Zn35Ca5 bulk metallic glass composite (BMGC) with fabricated implants in a rabbit tendon–bone interference fixation model. We investigated the cellular cytotoxicity of Mg60Zn35Ca5 BMGC toward rabbit osteoblasts and compared it with conventional titanium alloy (Ti6Al4V) and polylactic acid (PLA). The results show that Mg60Zn35Ca5 BMGC may be classed as slightly toxic on the basis of the standard ISO 10993-5. We further characterized the osteogenic effect of the Mg60Zn35Ca5 BMGC extraction medium on rabbit osteoblasts by quantifying extracellular calcium and mineral deposition, as well as cellular alkaline phosphatase activity. The results of these tests were found to be promising. The chemotactic effect of the Mg60Zn35Ca5 BMGC extraction medium on rabbit osteoblasts was demonstrated through a transwell migration assay. For the in vivo section of this study, a rabbit tendon–bone interference fixation model was established to determine the biocompatibility and osteogenic potential of Mg60Zn35Ca5 BMGC in a created bony tunnel for a period of up to 24 weeks. The results show that Mg60Zn35Ca5 BMGC induced considerable new bone formation at the implant site in comparison with conventional titanium alloy after 24 weeks of implantation. In conclusion, this study revealed that Mg60Zn35Ca5 BMGC demonstrated adequate biocompatibility and exhibited significant osteogenic potential both in vitro and in vivo. These advantages may be clinically beneficial to the development of Mg60Zn35Ca5 BMGC implants for future applications.

The physicochemical and biomechanical profile of forsterite and its osteogenic potential of mesenchymal stromal cells.

It has been demonstrated that nanocrystalline forsterite powder synthesised using urea as a fuel in sol-gel combustion method had produced a pure forsterite (FU) and possessed superior bioactive characteristics such as bone apatite formation and antibacterial properties. In the present study, 3D-scaffold was fabricated using nanocrystalline forsterite powder in polymer sponge method. The FU scaffold was used in investigating the physicochemical, biomechanics, cell attachment, in vitro biocompatibility and osteogenic differentiation properties. For physicochemical characterisation, Fourier-transform infrared spectroscopy (FTIR), Energy dispersive X-ray (EDX), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoemission spectrometer (XPS) and Brunauer-Emmett-Teller (BET) were used. FTIR, EDX, XRD peaks and Raman spectroscopy demonstrated correlating to FU. The XPS confirmed the surface chemistry associating to FU. The BET revealed FU scaffold surface area of 12.67 m2/g and total pore size of 0.03 cm3/g. Compressive strength of the FU scaffold was found to be 27.18 ± 13.4 MPa. The human bone marrow derived mesenchymal stromal cells (hBMSCs) characterisation prior to perform seeding on FU scaffold verified the stromal cell phenotypic and lineage commitments. SEM, confocal images and presto blue viability assay suggested good cell attachment and proliferation of hBMSCs on FU scaffold and comparable to a commercial bone substitutes (cBS). Osteogenic proteins and gene expression from day 7 onward indicated FU scaffold had a significant osteogenic potential (p<0.05), when compared with day 1 as well as between FU and cBS. These findings suggest that FU scaffold has a greater potential for use in orthopaedic and/or orthodontic applications.

Screening for osteogenic activity in extracts from Irish marine organisms: The potential of Ceramium pallidum.

Extracts and compounds derived from marine organisms have reportedly shown some osteogenic potential. As such, these bioactives may aid in the treatment of musculoskeletal conditions such as osteoporosis; helping to address inefficacies with current treatment options. In this study, 72 fractions were tested for their in vitro osteogenic activity using a human foetal osteoblast (hFOB) cell line and bone marrow derived mesenchymal stem cells (MSCs), focusing on their cytotoxic, proliferative and differentiation effects. Extracts dissolved in dimethyl sulfoxide and ethanol showed no significant osteogenic potential. However, two extracts derived from powder residues (left over from original organic extractions) caused a significant promotion of MSC differentiation. Bioactivity from powder residues derived from the epiphytic red algae Ceramium pallidum is described in detail to highlight its treatment potential. In vitro, C. pallidum was shown to promote MSC differentiation and extracellular matrix mineralisation. In vivo, this extract caused a significant increase in opercular bone growth of zebrafish larvae and a significant increase in bone density of regenerated adult caudal fins. Our findings therefore show the importance of continued screening efforts, particularly of novel extract sources, and the presence of bioactive compounds in C. pallidum extract.

Bone Density and Cross-sectional Geometry of the Proximal Femur Are Bilaterally Elevated in Elite Cricket Fast Bowlers

The skeleton of a cricket fast bowler is exposed to a unique combination of gravitational and torsional loading in the form of substantial ground reaction forces delivered through the front landing foot, and anterior-posterior shear forces mediated by regional muscle contractions across the lumbo-pelvic region. The objectives of this study were to compare the hip structural characteristics of elite fast bowlers with recreationally active age-matched controls, and to examine unilateral bone properties in fast bowlers. Dual-energy X-ray absorptiometry of the proximal femur was performed in 26 elite male fast bowlers and 26 normally active controls. Hip structural analysis (GE Lunar; enCORE version 15.0) determined areal bone mineral density (BMD) of the proximal femur, and cross-sectional area, section modulus (Z), cross-sectional moment of inertia, and femoral strength index at the narrow region of the femoral neck. Mean femoral neck and trochanter BMD were greater in fast bowlers than in controls (p < 0.001). All bone geometry properties, except for cross-sectional moment of inertia, were superior in fast bowlers (p < 0.05) following adjustment for height and lean mass. There were no asymmetries in BMD or bone geometry when considering leg dominance of the fast bowlers (p > 0.05). Elite fast bowlers have superior bone characteristics of the proximal femur, with results inferring enhanced resistance to axial compression (cross-sectional area), and bending (Z) forces, and enhanced strength to withstand a fall impact as indicated by their higher femoral strength index. No asymmetries in hip bone properties were identified, suggesting that both torsional and gravitational loading offer significant osteogenic potential.

Effects of carbon doping on the microstructural, micro/nano-mechanical, and mesenchymal stromal cells biocompatibility and osteogenic differentiation properties of alumina

It has been demonstrated that carbon (C) doped aluminium oxide (Al2O3) nanocomposite (C −0.012wt%) had greater wear resistance and lower surface grains pull out percentage when compared with monolithic Al2O3. In the present study, we investigated the physicochemical, micro- and nanomechanical, cell attachment, in vitro biocompatibility and osteogenic differentiation properties of Al2O3 doped carbon (0.012wt%) nanocomposite (Al2O3/C). Data were compared to values obtained for monolithic alumina (Al2O3). The calcined Al2O3/C nanocomposite was densified using cold isostatic pressing and followed by pressureless sintering. For physicochemical and microstructural characterisation, Energy dispersive X-ray (EDX), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoemission spectrometer (XPS) were used. EDX, XRD peaks and Raman spectroscopy demonstrated correlating to Al2O3/C. Surface profiling and contact angle investigations demonstrated highly contoured micro-surface topography. The micro and nano-hardness indicate an improved wear resistance of the Al2O3/C when compared with monolithic Al2O3. SEM, confocal images and alamar blue reduction assay suggested good cell attachment and proliferation of human bone marrow derived mesenchymal stromal cells (hBMSCs). Osteogenic protein and gene expression indicated Al2O3/C had a significant osteogenic potential (p<0.05) when compared with Al2O3. In conclusion, our novel Al2O3/C nanocomposite had improved mechanical properties. It also supports cell attachment and proliferation which are comparable to Al2O3. However, Al2O3/C has a significant osteogenic potential than that of Al2O3. These findings suggest that Al2O3/C nanocomposite is superior to Al2O3 and thus has a greater potential for use in orthopaedic applications.

Bone Graft Substitutes for Anterior Lumbar Interbody Fusion

The procedure of anterior lumbar interbody fusion (ALIF) is commonly performed on patients suffering from pain and/or neurological symptoms associated with disorders of the lumbar spine caused by disc degeneration and trauma. Surgery is indicated when prolonged conservative management proves ineffective. Because an important objective of the ALIF procedure is solid arthrodesis of the degenerative spinal segment, bone graft selection is critical. Iliac crest bone grafts (ICBG) remain the "gold standard" for achieving lumbar fusion. However, patient dissatisfaction stemming from donor site morbidity, lengthier operating times and finite supply of ICBG has prompted a search for better alternatives. Here presented is a literature review evaluating available bone graft options assessed within the clinical setting. These options include autografts, allograft-based, synthetic and cell-based technologies. The emphasis is on the contentious use of recombinant human bone morphogenetic proteins, which is in widespread use and has demonstrated both significant osteogenic potential and risk of complications.

Human Periosteum‐Derived Cells Combined With Superporous Hydroxyapatite Blocks Used as an Osteogenic Bone Substitute for Periodontal Regenerative Therapy: An Animal Implantation Study Using Nude Mice

A superporous (85%) hydroxyapatite (HA) block was recently developed to improve osteoconductivity, but it was often not clinically successful when used to treat periodontal osseous defects. The primary purpose of this study is to develop a clinically applicable tissue-engineered bone substitute using this HA block and human alveolar periosteum-derived cells. Commercially available superporous HA blocks were acid treated and subjected to a three-dimensional (3D) culture for periosteal cell cultivation. Cells in the pore regions of the treated HA block were observed on the fracture surface by scanning electron microscopy. After osteogenic induction, the cell-HA complexes were implanted subcutaneously in nude mice. Osteoid formation was histologically evaluated. Acid treatment enlarged the interconnections among pores, resulting in the deep penetration of periosteal cells. Under these conditions, cells were maintained for >2 weeks without appreciable cell death in the deep pore regions of the HA block. The cell-HA complexes that received in vitro osteogenic induction formed osteoids in pore regions of the treated HA blocks in vivo. In contrast, most pore regions in the non-pretreated, cell-free HA blocks that were evaluated in vivo remained cell free. Our findings suggest that an acid-treated HA block could function as a better scaffold for the 3D high-density culture of human periosteal cells in vitro, and this cell-HA complex had significant osteogenic potential at the site of implantation in vivo. Compared with the cell-free HA block, our cell-HA complex using periosteal cells, which are the most accessible for clinical periodontists, showed promising results as a bone substitute in periodontal regenerative therapy.

In vivo bone formation by human bone marrow stromal cells: effect of carrier particle size and shape.

Successful closure of bone defects in patients remains an active area of basic and clinical research. A novel and promising approach is the transplantation of human bone marrow stromal cells (BMSCs), which have been shown to possess a significant osteogenic potential. The extent and quality of bone formation by transplanted human BMSCs strongly depends on the carrier matrix with which cells are transplanted; to date, hydroxyapatite/tricalcium phosphate (HA/TCP) supports far more osteogenesis than any other matrix tested. In order to further improve the technique of BMSC transplantation, we studied whether commercially available HA/TCP particles, clinically approved as an osteoconductive material and commercially available as particles measuring 0.5-1.0 mm diameter, is an optimum matrix for promoting bone development by BMSCs. HA/TCP and HA particles of varying size were sieved into a variety of size ranges, from <0.044 mm to 1.0-2.0 mm. Transplants were formed by mixing 40 mg aliquots of particles with cultured passaged human BMSCs. They were placed in subcutaneous pockets in immunocompromised Bg-Nu-XID mice and harvested 4 or 10 weeks later. The transplants were examined histologically; the presence of bone within each transplant was evaluated using histomorphometry or blindly scored on a semiquantitative scale. Transplant morphology and the amount of new bone varied in a consistent fashion based on particle size and shape. Transplants incorporating HA/TCP particles of 0.1-0.25 mm size demonstrated the greatest bone formation at both 4 and 10 weeks; larger or smaller particles were associated with less extensive bone formation, while a size of 0.044 mm represented a threshold below which no bone formation could be observed. Flat-sided HA particles measuring 0.1-0.25 mm formed no bone. The differences in bone formation were not attributable to the differences in cell attachment among the groups. Instead, the size and spatial and structural organization of the particles within BMSC transplants appear to determine the extent of bone formation. These findings provide necessary information for the successful clinical application of BMSC transplantation techniques.

Periosteal augmentation of the acetabulum.

The periosteum in children and especially infants has significant osteogenic potential. To determine the efficacy of periosteal flaps to assist in improving acetabular coverage in children with acetabular dysplasia, a series of experiments were designed using young rabbits. Three groups of five rabbits each had periosteal flaps fashioned and brought down from the anterolateral aspect of the innominate bone superior to the acetabulum and sutured to the capsule of the hip. The study was designed to examine the effects of the periosteal cambium layer in the formation of new bone to augment the acetabulum and to determine the effects of a periosteal flap plus cancellous bone graft. A control group of five rabbits underwent a sham operation of an open arthrotomy of the hip. Radiographic and histologic examination at 12 weeks revealed augmentation of the acetabulum with periosteal flaps that resulted in an average improvement of the acetabular index of 3.5 degrees and 6.6 degrees, without and with bone graft, respectively. New bone formation from the rim of the acetabulum averaged 3.9 mm with periosteal flaps alone and 4.6 mm with bone graft added. Periosteal augmentation of the acetabulum in conjunction with established procedures for augmenting acetabular coverage would appear to be a useful procedure for improving coverage of the femoral head in children with acetabular dysplasia.