Osteoblast Cell Growth Research Articles

Injectable Bone Substitute Paste Based on Hydroxyapatite, Gelatin and Streptomycin for Spinal Tuberculosis

World Health Organization (WHO) in 2005 reported that cases of tuberculosis (TB) in the world occur more than 8 million annually and 5-10% were attacked in spine. The most effective treatment of spinal TB is evacuation of infected bone segments and fill with bone graft. It has been synthesized and characterized of injectable bone substitute (IBS) paste based on hydroxyapatite, gelatin and streptomycin. IBS paste synthesized by mixing hydroxyapatite and gelatin 20% w/v with 75:25, 70:30, 65:35 and 60:40 ratio and streptomycin 10 wt%. The mixture was then added with hydroxypropyl methylcellulose (HPMC) 4% w/v as suspending agent. In vitro characterization performed include acidity (pH), injectability test, setting time, cytotoxicity (MTT assay) and microbacterium test. Acidity test results indicate a fourth variation of the samples had pH values approaching normal body pH (7,3 to 7,6) and is able to maintain stability when measured in 7 days. Injectability test results indicate IBS paste is injectable with the highest percentage of the injectability value at 97,74% ± 0,19%. IBS paste has been setting within 30 minutes to 1 hour when injected on hydroxyapatite scaffold that resembles the bone cavity and is able to cover the pore scaffold seen from the Scanning Electron Microscope (SEM). Scaffold pore size is smaller from range of 780,8 to 835,4 μm into 225,2 μm. MTT assay results showed that IBS paste is not toxic and experiencing proliferation (viability >100%) that are expected to trigger osteoblast cell growth when applied. Microbacterium test results showed that IBS paste is an antibacterial seen from inhibition zone diameter of Staphylococcus aureus and has a high strength-sensitive antibacterial. Thus, hydroxyapatite, gelatin and streptomycin composites had qualified as injectable bone substitute which applied in cases of spinal tuberculosis.

Long acting anti-infection constructs on titanium

Peri-prosthetic joint infections (PJI) are a serious adverse event following joint replacement surgeries; antibiotics are usually added to bone cement to prevent infection offset. For uncemented prosthesis, alternative antimicrobial approaches are necessary in order to prevent PJI; however, despite elution of drug from the surface of the device being shown one of the most promising approach, no effective antimicrobial eluting uncemented device is currently available on the market. Consequently, there is a clinical need for non-antibiotic antimicrobial uncemented prosthesis as these devices present numerous benefits, particularly for young patients, over cemented artificial joints. Moreover, non-antibiotic approaches are driven by the need to address the growing threat posed by antibiotic resistance.We developed a multilayers functional coating on titanium surfaces releasing chlorhexidine, a well-known antimicrobial agent used in mouthwash products and antiseptic creams, embedding the drug between alginate and poly-beta-amino-esters.Chlorhexidine release was sustained for almost 2 months and the material efficacy and safety was proven both in vitro and in vivo. The coatings did not negatively impact osteoblast and fibroblast cells growth and were capable of reducing bacterial load and accelerating wound healing in an excisional wound model.As PJI can develop weeks and months after the initial surgery, these materials could provide a viable solution to prevent infections after arthroplasty in uncemented prosthetic devices and, simultaneously, help the fight against antibiotic resistance.

Osteoclast and osteoblast response to strontium-doped struvite coatings on titanium for improved bone integration.

To develop implants with improved bone ingrowth, titanium substrates were coated with homogeneous and dense struvite (MgNH4PO4·6H2O) layers by means of electrochemically assisted deposition. Strontium nitrate was added to the coating electrolyte in various concentrations, in order to fabricate Sr-doped struvite coatings with Sr loading ranging from 10.6 to 115μg/cm2. It was expected and observed that osteoclast activity surrounding the implant was inhibited. The cytocompatibility of the coatings and the effect of Sr-ions in different concentrations on osteoclast formation were analyzed in vitro. Osteoclast differentiation was elucidated on morphological, biochemical as well as on gene expression level. It could be shown that moderate concentrations of Sr2+ had an inhibitory effect on osteoclast formation, while the growth of osteoblastic cells was not negatively influenced compared to pure struvite surfaces. In summary, the electrochemically deposited Sr-doped struvite coatings are a promising approach to improve bone implant ingrowth.

TiO2 nanotubes synthesised on Ti-6Al-4V ELI exhibits enhanced osteogenic activity: A potential next-generation material to be used as medical implants

ABSTRACT Ti-6Al-4 V and Ti-6Al-4 V ELI alloys were surface modified with nanotube layers by electrochemical anodisation technique. Osteoblast cell viability and their osteogenic behaviour were studied. It was found that the pore diameters of the nanotubes were in the range of 70–105 nm for Ti-6Al-4 V sample and 60–130 nm for Ti-6Al-4 V ELI sample. Porosity was calculated to be in the range of 75–85% of the total volume of formed nanotubes. Pores were arranged in a self-organised nanotube structure and the nanotubes emanated from the pores. MG63 cells cultured on the samples for 1, 7 and 14 days showed significant osteoblast cell growth on Ti-6Al-4 V ELI surface as compared to the grade 5 titanium alloy. CCK-8 assay results confirmed better cytocompatibility of the Ti-6Al-4 V ELI nanotube surface than the Ti-6Al-4 V surface which were ascribed to various inert or toxic ions released to the medium from Ti-6Al-4 V matrix.

Electrospun chitosan/polyethylene-oxide (PEO)/halloysites (HAL) membranes for bone regeneration applications

Fabricating biomaterials that mimic the extracellular matrix (ECM) environment of human tissue with appropriate functional, biomechanical, and biocompatible properties remains a challenge. This research aims to fabricate chitosan/polyethylene-oxide (PEO) membranes reinforced with halloysite nanotubes (HAL) as potential scaffolds for bone regeneration applications through facile electrospinning method. Morphological study through FESEM and STEM imaging demonstrated the presence of HAL along the chitosan/PEO fiber matrix with average fiber diameter ranged from 72.07 ± 3.30 nm to 154.87 ± 6.77 nm. Furthermore, the membranes incorporated with up to 5 wt% HAL revealed to have a larger pore, which was suitable for bone regeneration applications. Moreover, the mechanical tests showed that the fabricated chitosan/PEO/HAL membranes exhibited appropriate tensile strength properties to support the growth of osteoblast cells. Thermal stability analysis showed an improved behavior with the addition of HAL to the chitosan/PEO membranes. In addition, the surface wettability of the chitosan/PEO membrane reinforced with 0–5 wt% of HAL ranged between 0 to 75o, thus showed a hydrophilic nature appropriate for bone tissue regeneration. Besides, natural human osteoblast cell (NHOst) culturing demonstrated the cell adhesion and cell interaction with chitosan/PEO with 5 wt% HAL membrane through the attachment of matured NHOst and primary osteoblast cells on the membranes. Further in vitro analysis revealed that chitosan/PEO with 5 wt% HAL membranes increased the ALP activity by 2.5 times at the 14 days. In summary, the results obtained from this study demonstrated the potential of chitosan/PEO/HAL membranes for bone regeneration applications.

Design, characterization and evaluation of β-hairpin peptide hydrogels as a support for osteoblast cell growth and bovine lactoferrin delivery.

The use of peptide hydrogels is of growing interest in bone regeneration. Self-assembling peptides form hydrogels and can be used as injectable drug delivery matrices. Injected into the defect site, they can gel in situ, and release factors that aid bone growth. We report on the design, synthesis and characterization of three β-hairpin peptide hydrogels, and on their osteoblast cytocompatibility as well as delivery of the lactoferrin glycoprotein, a bone anabolic factor. Osteoblasts cultured in hydrogels of the peptide with sequence NH2-Leu-His-Leu-His-Leu-Lys-Leu-Lys-Val-dPro-Pro-Thr-Lys-Leu-Lys-Leu-His-Leu-His-Leu-Arg-Gly-Asp-Ser-CONH2 (H4LMAX-RGDS) increased the osteoblast cell number and the cells appeared healthy after seven days. Furthermore, we showed that H4LMAX-RGDS was capable of releasing up to 60% of lactoferrin (pre-encapsulated in the gel) over five days while retaining the rest of the glycoprotein. Thus, H4LMAX-RGDS hydrogels are cytocompatible with primary osteoblasts and capable of delivering bio-active lactoferrin that increases osteoblast cell number.

Effects of surface roughening and calcite coating of titanium on cell growth and differentiation.

Medical pure titanium (Ti) exhibits excellent mechanical properties and chemical stability in clinical use, but its initial osteointegration period is often postponed due to the bioinert nature of the Ti surface. Roughening and bioactive material coating of Ti implant surfaces are considered effective to enhance the bioactivity of Ti implants. In this study, we evaluated the effects of surface roughening and calcite (CaCO3) coating of Ti substrates on osteoblastic cell differentiation and growth. We roughened the Ti substrate surface by acid etching, followed by coating with calcite by thermal decomposition of Ca(NO3)2 to CaO followed by thermal carbonation of CaO to CaCO3. The surface topography of roughened Ti substrates (rough Ti) fluctuated, and the arithmetic average of surface roughness (Ra) was 2.2 µm. The rough topography was retained even after calcite coating of rough Ti, and the calcite-coated Ti (calcite-Ti) has an Ra of 2.0 µm. The tensile adhesive and shear adhesive strengths between calcite coating and Ti surface in calcite–Ti were 56.6 ± 16.1 and 10.1 ± 1.39 MPa, respectively. The biological properties and response of calcite–Ti were evaluated in vitro using a pre-osteoblastic cell line (MC3T3-E1). Observation of cell morphology by scanning electron microscopy and immunofluorescence staining revealed that MC3T3-E1 cells attached favorably to the surface with polygonal and filopodial extensions on calcite–Ti. The combination of roughening and calcite coating of the Ti substrate surface significantly increased cell proliferation at 1, 3, and 7 days of incubation. Furthermore, the relative alkaline phosphatase activity of calcite–Ti was higher than that of untreated Ti substrates (smooth Ti) and rough Ti after incubation for 7 days. Thus, the combined surface roughening and calcite coating of Ti substrates promoted MC3T3-E1 differentiation, whereas roughening alone was not effective.

Osteoadherin serves roles in the regulation of apoptosis and growth in MC3T3‑E1 osteoblast cells.

Small leucine‑rich proteoglycans (SLRPs) are a class of proteoglycans that are characterized by small protein cores and structures of leucine‑rich repeats. SLRPs are expressed in most extracellular matrices and share numerous biological functions that are associated with binding of collagens and cell surface receptors. Osteoadherin (also termed osteomodulin) is encoded by the Omd gene and is a keratan sulfate proteoglycan of the class II subfamily of SLRPs. Osteoadherin is highly expressed in mineralized tissues, including bone and dentin; however, it's precise roles remain unknown. The present study determined the Omd expression levels and investigated the effects of over‑ and under‑expression of osteoadherin in osteoblastic cells. Omd mRNA expression increased with osteoblast differentiation in MC3T3‑E1 cells. In C2C12 cells, Omd mRNA expression was induced by bone morphogenetic protein (BMP)2. Reporter assays similarly demonstrated activation of the Omd gene promoter following co‑transfection with Smad1 and Smad4, which are intracellular signaling molecules of the BMP2 signaling pathway. Overexpression of Omd increased the viability and decreased caspase 3/7 activity in MC3T3‑E1 cells. By contrast, following transfection with small interfering RNA for Omd, viable cell numbers were decreased and caspase 3/7 activity was increased. Furthermore, overexpression of Omd reduced the expression of CCN family 2 in these cells. These results demonstrate that Omd expression is regulated during osteoblast differentiation, and that the protein product osteoadherin serves roles in the apoptosis and growth of osteoblast cells.

Electrospun PCL nanofibers blended with Wattakaka volubilis active phytochemicals for bone and cartilage tissue engineering

In the present study, the polycaprolactone (PCL) nanofibers were investigated as a carrier to deliver phytochemicals for bone and cartilage tissue engineering. The PCL nanofibers was blended with phytochemicals hexadecanoic acid, octadecanoic acid and N,N-diisopropyl (2,2,3,3,3-pentafluoropropyl) amine isolated from a medicinal plant, Wattakaka volubilis. The scaffolds were characterized using scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy. The average diameter of control and phytochemical loaded nanofiber was 208 ± 9.6 nm and 316 ± 7.0 nm respectively. Biodegradation rate of nanofibers, impact of nanofiber on meniscus and osteoblast cell growth was analyzed using 3-(4,5-dimethyl thiazolyl-2)-2,5-diphenyl tetrazolium bromide (MTT) assay, DNA content and extra cellular matrix secretion. Hoechst stain and SEM images were used to visualize and monitor the cell growth on PCL scaffold. The phytochemicals incorporated PCL nanofibers enhanced the growth and proliferation of primary human meniscus and osteoblast like cells and hence may be suitable scaffold for bone and cartilage tissue engineering applications.

Incorporation of shRNA in bioactive glass coated SS316L implant material and its role in inhibition of the osteoclast activity for better post implantation fixation

The possibility of the use of small non-coding RNAs as therapeutics in targeted treatment of damaged hard tissue are presently being explored largely and for the same, a good understanding of the underlying molecular mechanisms of osteoblast and osteoblast differentiation is necessary, which would lead to better fixation of the implant. In the present communication, we made an attempt to incorporate a model non coding RNA viz. short hairpin RNA (shRNA), in the form of shRNA-plasmid, in a porous bioactive coating of phosphate free bioactive glass (PFBG) on surgical grade SS316L implant material, used as reservoir/carrier of the biomolecule and evaluated its time dependent inhibitory action on the osteoclastogenic cytokine, tumor necrosis factor alpha (TNFα), that in turn aids in growth and differentiation of osteoblast cells, for faster remodelling, repair and healing of the damaged hard tissue at the implanted site. Upon treatment with the shRNA-plasmid, results exhibited significant downregulation (approximately 12-fold) of the TNFα, as evidenced from the sandwich ELISA assay and confirmed by quantitative reverse transcription–polymerase chain reaction (qRT–PCR) analysis, followed by upregulation of alkaline phosphatase (approximately 4-fold), corresponding to osteoblast formation, on the contrary, confirming a pivotal role of the same in osteoblast formation. The flow cytometry data showed significant cellular uptake (16.04%) of the shRNA-plasmid into osteoclast cells at a time period of 24h, that was in turn corroborated by confocal imaging.

Fabrication of bioactive rifampicin loaded κ-Car-MA-INH/Nano hydroxyapatite composite for tuberculosis osteomyelitis infected tissue regeneration.

Biocompatible polymers and ceramic materials have been identified as vital components to fabricate drug delivery and tissue engineering applications because of their high drug loading capability, sustained release and higher mechanical strength with remarkable in-vivo bioavailability. In the present work, initially we designed κ-carrageenan grafted with maleic anhydride and then reacted it with isoniazid drug (κ-Car-MA-INH). The polymeric system was cross linked with nanohydroxyapatite (NHAP) via electrostatic interaction followed by the addition of rifampicin (RF) and loaded to fabricate κ -Car-MA-INH/NHAP/RF nanocomposites. The chemical modification and interaction of drug with the polymeric-ceramic system were characterised by Fourier Transform Infrared spectroscopy (FT-IR). The zeta potential of the κ -Car-MA-INH/NHAP/RF nanocomposite was observed to be -20.04 mV using Zetasizer. The in vitro drug release studies demonstrated that the nanocomposite releases 76% of RF and 82% of INH in 12 days at pH 5.5. Scanning Electron Microscope analysis revealed the structural deformation of Staphylococcus aureus and Klebsiella pneumoniae upon treatment with this nanocomposite. By using ex-vivo studies combined with physio-chemical characterization methods on the erythrocytes, L929 and MG-63 cell lines, this composite was found to be biocompatible, non-cytotoxic and inducing cell proliferation with less significant hemolysis. Thus, our modified drug delivery nanocomposites afforded higher drug bioavailability with large potential for fabrication as long-acting drug delivery nanocomposites, especially with hydrophobic drugs inducing the growth of osteoblastic bone cells.

Porous 3-D thermoplastic polyurethane (TPU) scaffold modified with hydroxyapatite (HA) nanoparticles using an ultrasonic method

In this work, a 3-D porous hydroxyapatite (HA)-decorated thermoplastic polyurethane (TPU) scaffold with high porosity and excellent biocompatibility was successfully fabricated using a simple ultrasonic method. It was found that HA nanoparticles were successfully introduced onto the surface of the TPU scaffold, and a strong interaction occurred between the HA nanoparticles and the TPU matrix. The porosity was calculated to be about 87%. The water contact angle decreased from 121.1° for TPU to 44.6° for HA-decorated TPU scaffolds. The water absorption and mechanical properties of HA-decorated TPU scaffolds were significantly higher than those of TPU scaffolds. Compared with TPU scaffolds, the addition of HA nanoparticles effectively improved the attachment and growth of mouse embryonic osteoblast cells (MC3T3-E1) cultured on the HA-decorated TPU scaffolds. These results suggest that HA-decorated TPU scaffolds possess great potential to be used as tissue engineering scaffolds. Furthermore, the ultrasonic technique could be used as a simple, effective, and universal method for decorating tissue engineering scaffolds.

Mechanically Strong Silica-Silk Fibroin Bioaerogel: A Hybrid Scaffold with Ordered Honeycomb Micromorphology and Multiscale Porosity for Bone Regeneration.

Due to the synergic feature of individual components in hybrid (nano)biomaterials, their application in regenerative medicine has drawn significant attention. Aiming to address all the current challenges of aerogel as a potent scaffold in bone tissue engineering application, we adopted a novel synthesis approach to synergistically improve the pore size regime and mechanical strength in the aerogel. The three-dimensional aerogel scaffold in this study has been synthesized through a versatile one-pot aqueous-based sol-gel hybridization/assembly of organosilane (tetraethyl orthosilicate) and silk fibroin (SF) biopolymer, followed by unidirectional freeze-casting of the as-prepared hybrid gel and supercritical drying. The developed ultralight silica-SF aerogel hybrids demonstrated a hierarchically organized porous structure with interesting honeycomb-shaped micromorphology and microstructural alignment (anisotropy) in varied length scales. The average macropore size of the hybrid aerogel lied in ∼0.5-18 μm and was systematically controlled with freeze-casting conditions. Together with high porosity (91-94%), high Young's modulus (∼4-7 MPa, >3 order of magnitude improvement compared to their pristine aerogel counterparts), and bone-type anisotropy in the mechanical compressive behavior, the silica-SF hybrid aerogel of this study acted as a very competent scaffold for bone tissue formation. The results of in vitro assessments revealed that the silica-SF aerogel is not only cytocompatible and nonhemolytic but also acted as an open porous microenvironment to trigger osteoblast cell attachment, growth, and proliferation on its surface within 14 days of incubation. Moreover, to support the in vitro results, in vivo bone formation within the aerogel implant in the bone defect site was studied. The X-ray radiology and microcomputed tomography analyses confirmed that a significant new bone tissue density formed in the defect site within 25 days of implantation. Also, in vivo toxicology studies showed a zero-toxic impact of the aerogel implant on the blood biochemical and hematological parameters. Finally, the study clearly shows the potential of aerogel as a bioactive and osteoconductive open porous cellular matrix for a successful osseointegration process.

Fatigue behavior of plasma sprayed structural-grade hydroxyapatite coating under simulated body fluids

The plasma sprayed hydroxyapatite coating (HA) has shown promising prospects in orthopedic implant and dental surgery. The long-term stability of the coating is largely dependent upon the coating integrity, particularly the coating/substrate adhesion and coating crystallinity. However, the short-term clinical performance required that the coating should have loose structure containing some soluble phases, which can promote the osteoblast cells growth and bone fixation after surgery. The first step of this work was to develop a strategy to deposit a graded bi-layer HA coating, in which the bottom layer was dense with high crystallinity and well-adhered to substrate, while the top layer was porous with loose structure. By turning the spraying parameters, especially the melting state of spraying particles and the substrate temperature, the coating with different structural characteristics was prepared on Ti-6Al-4V substrate. Then, the structurally graded HA coating was investigated in vitro for fatigue test. It was shown that spalling was preferentially generated at the loose-structure top layer under cyclic stress. The dense-structure layer with higher bond strength presented improved resistance to crack propagation and therefore the dense layer was favorable to maintain the long-term integrity of coating.

Silicon nitride enhances osteoprogenitor cell growth and differentiation via increased surface energy and formation of amide and nanocrystalline HA for craniofacial reconstruction

The bioactive silicon nitride (Si3N4) has been FDA cleared for use as spinal intervertebral arthrodesis devices. Because its surface properties promote bone ongrowth and ingrowth, it also has the potential to benefit craniofacial reconstruction. Thus, the aim of this work was to determine whether the surface properties of Si3N4 could enhance the osteoblast cell growth, differentiation and nucleation of hydroxyapatite (HA) crystals compared to conventional implant materials such as titanium (Ti) and polyether ether ketone (PEEK). X-ray absorbance near-edge structure analysis (XANES) indicated the presence of Si-Si, Si-O and Si-N bonding. Surface wettability studies confirmed that Si3N4 exhibits the lowest contact angle and highest surface energy. Cell culture studies showed that osteoblast growth was enhanced on Si3N4 after 1 day and up to 7 days. Si3N4 surface induced highest surface coverage and thickness of nanocrystalline HA (211) and (203) in cell-free in vitro studies after 7 days of culture. Raman spectroscopy analysis confirmed the presence of surface functional groups consisting of phosphate and carbonate species. Interestingly, Si3N4 surface showed amide and hydroxyproline groups, the precursors to collagen, which were not observed on Ti and PEEK surfaces. Furthermore, Si3N4 surface indicated high expression of RUNX2, enhanced cell differentiation and dense collagenous ECM after 30 days of the in vitro study. The present study concluded that Si3N4 surface enhances osteoprogenitor cell adhesion, growth, RUNX2 expression and ECM formation via the coupled effects of higher surface energy and the presence of amide and nanocrystalline HA functional groups.

A hybrid platform for three-dimensional printing of bone scaffold by combining thermal-extrusion and electrospinning methods

The aim of this study is to develop a hybrid 3D printing platform integrating thermal-extrusion and electrospinning methods to fabricate bone scaffolds. The scaffolds made by mPEG–PCL–mPEG/HA biocomposite and their surface were enhanced by adding an electrospun fibre layer which improved adhesion and viability of osteoblastic cells. The scaffolds were evaluated by mechanical testing; biochemical analyses, SEM observation and their capabilities for supporting growth and adhesion of osteoblastic cells were also assessed in vitro. The 3D printing platform can manufacture the controllable and complicated shapes of bone scaffolds by controlling the thermal-extrusion and electrospinning equipment. It also can control the pore size, porosity and pore interconnectivity, and stack the scaffold structure by using different materials and different ways. Analyses showed that the bone scaffolds have a good mechanical strength and the scaffolds are suitable to support growth of MC3T3-E1 osteoblastic cells; and the electrospun fibres may increase the surface area of the fabricated scaffolds for the future application in modulating osteoblast response. Thus, it is feasible to produce bone tissue engineering scaffolds integrating thermal-extrusion and electrospinning techniques using our 3D printing platform.

Iron overload threatens the growth of osteoblast cells via inhibiting the PI3K/AKT/FOXO3a/DUSP14 signaling pathway.

Iron overload is a common stress in the development of cells. Growing evidence has indicated that iron overload is associated with osteoporosis. Therefore, enhancing the understanding of iron overload would benefit the development of novel approaches to the treatment of osteoporosis. The purpose of the present study was to analyze the effect of iron overload on osteoblast cells, via the MC3T3-E1 cell line, and to explore its possible underlying molecular mechanisms. Ferric ammonium citrate (FAC) was utilized to simulate iron overload conditions in vitro. FAC-induced iron overload strongly suppressed proliferation of osteoblast cells and induced apoptosis. Moreover, iron overload strongly suppressed the expression of dual-specificity phosphatase 14 (DUSP14). Additionally, overexpression of DUSP14 protected osteoblast cells from the deleterious effects of iron overload, and this protective effect was mediated by FOXO3a. Additionally, matrine rescued the function of DUSP14 in osteoblast cells. Most importantly, our analysis demonstrated the essential role of the PI3K/AKT/FOXO3a/DUSP14 signaling pathway in the defense against iron overload in osteoblast cells. Overall, our results not only elucidate deleterious effects of iron overload, but also unveil its possible signaling pathway in osteoblast cells.

Preparation and characterization of a piezoelectric poly (vinylidene fluoride)/nanohydroxyapatite scaffold capable of naproxen delivery

Piezoelectric polymers are of great interest because of their ability to produce temporary surface electric charge, which can have a positive impact on the growth, attachment and proliferation of osteoblastic cells. The aim of this study was to combine potential osteoinductive properties of piezoelectric PVDF with the excellent bioactivity of nHA. In this regard, PVDF/nHA composite scaffolds were fabricated via a solvent casting/particulate leaching (SC/PL) method. The composite scaffold at 5 wt% nHA was annealed for 5 h at 60 °C and 90 °C in order to induce α to β phase transformation. Naproxen (NAP) was chosen as a reference drug and was complexed with beta-cyclodextrin (βCD) to form an inclusion complex (NAP-βCD-IC). Both NAP and NAP-βCD-IC were incorporated into PVDF solution during the fabrication process. The results showed that pore size and porosity both increased with the addition of nHA up to 5 wt%. The compressive modulus and strength of the scaffolds was increased with increasing nHA content in the composite. Fourier transform infrared (FTIR) spectroscopy confirmed increased β phase content due to annealing, and a higher increment was achieved for samples annealed at 90 °C. Superior cell viability was observed in the sample with a higher amount of piezoelectric β phase compared with the as-prepared sample and the sample annealed at 60 °C. The release profile of NAP from the PVDF/nHA composite scaffold showed that the formation of NAP-βCD inclusion complexes increased the rate and amount of NAP release from the scaffold.

Effects of Therapeutic Doses of Celecoxib on Several Physiological Parameters of Cultured Human Osteoblasts.

Non-steroidal anti-inflammatory drugs (NSAIDs), including cyclooxygenase-2 (COX-2)-selective NSAIDs, are associated with adverse effects on bone tissue. These drugs are frequently the treatment of choice but are the least studied with respect to their repercussion on bone. The objective of this study was to determine the effects of celecoxib on cultured human osteoblasts. Human osteoblasts obtained by primary culture from bone samples were treated with celecoxib at doses of 0.75, 2, or 5μM for 24 h. The MTT technique was used to determine the effect on proliferation; flow cytometry to establish the effect on cell cycle, cell viability, and antigenic profile; and real-time polymerase chain reaction to measure the effect on gene expressions of the differentiation markers RUNX2, alkaline phosphatase (ALP), osteocalcin (OSC), and osterix (OSX). Therapeutic doses of celecoxib had no effect on osteoblast cell growth or antigen expression but had a negative impact on the gene expression of RUNX2 and OSC, although there was no significant change in the expression of ALP and OSX. Celecoxib at therapeutic doses has no apparent adverse effects on cultured human osteoblasts and only inhibits the expression of some differentiation markers. These characteristics may place this drug in a preferential position among NSAIDs used for analgesic and anti-inflammatory therapy during bone tissue repair.

A nanodiamond for structural biomimetic scaffolds

Bio-mechanically active scaffolds for tissue engineering combining hydrophilic polymeric matrix and nano-diamond fillers properties are presented and discussed in this paper. The resulting scaffolding materials revealed remarkable mechanical and biological properties to be exploited in advanced biomedical applications. The novel hybrid material is based on 2 and 5 volume % of detonation nano-diamond particles in a hydrophilic poly-(hydroxyl-ethylmethacrylate) matrix. According to its mechanical and biological properties, the nanocomposite shows a hybrid nature. The base analytical procedures for the preparation of the hybrid nanocomposites and some preliminary mechanical characteristics are presented. The proposed hybrid system has been considered for potential biomimetic, osteoconductive and osteoinductive scaffolds application in bio-mechanically active bone scaffolds for osteoblast and stem cell differentiation and growth. These more rigid hybrid nano-composites are predicted to possess improved mechanical strength overcoming the mechanical weaknesses of traditional hydrogels clinically utilized for bone regeneration.