Beta-tricalcium Phosphate Research Articles

Serum biochemical evaluation of healing of critical-sized long bone defects in rats treated with biphasic hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) bioceramic scaffolds

Critical-sized long bone defects are those that would not heal spontaneously despite surgical stabilisation. The use of bioceramic scaffold has shown promising results in the repair of bone defects. The present study was undertaken to evaluate the serum biochemical parameters of Wistar rats treated for critical-sized segmental bone loss using biphasic hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) bioceramic scaffolds. The study was conducted in eighty male Wistar rats aged between 8-12 weeks, weighing 200-250 g body weight with critical-sized segmental defects in the femur. A 6 mm segmental mid-diaphyseal femoral defect was created under general anaesthesia. The bone defect was bridged with bioceramic scaffolds and retained in position with microplate and screws. Serum biochemical parameters serum calcium, phosphorous, acid phosphatase and alkaline phosphatase were evaluated four weeks before surgery, immediately after surgery and 4th, 8th, 12th, and 16th week after surgery. The evaluation of both serum calcium and phosphorous were found to be reliable indicators of new bone formation and mineralisation, whereas the evaluation of both serum acid phosphatase and alkaline phosphatase were found to be reliable indicators of bone healing during the treatment of critical-sized long bone defects in rats using biphasic hydroxyapatite and β-tricalcium phosphate bioceramic scaffolds Keywords: Beta-tricalcium phosphate, bioceramic scaffold, hydroxyapatite, serum acid phosphatase, serum alkaline phosphatase, serum calcium, serum phosphorous

Biomechanical evaluation of healing of critical-sized long bone defects in rats treated with biphasic hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) bioceramic scaffolds

Critical-sized bone defects are those that would not heal spontaneously despite surgical stabilisation. These defects are treated using autografts, allografts, xenografts and synthetic bone grafts. The present study was undertaken to evaluate the efficacy of biphasic hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) bioceramic scaffolds in treating critical-sized segmental bone loss in rats. The study was conducted in sixty male Wistar rats aged between 8-12 weeks, weighing 200-250 g body weight with critical-sized defects in the right femur. A six-mm segmental mid-diaphyseal femoral defect was created under general anaesthesia. The bone defect was bridged with biphasic hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) bioceramic scaffolds and retained in position with microplate and screws. Fifteen rats were sacrificed as per the guidelines of CCSEA during the 4th, 8th, 12th and 16th week post-surgery. The treated bone and contralateral femur were harvested and subjected to a three-point bending test, torsion test and compression test to compare the regained strength of the repaired right femur with that of the intact contralateral left femur. From the present study, it was observed that the use of biphasic hydroxyapatite and β-tricalcium phosphate bioceramic scaffolds in the treatment of critical-sized long bone defects in rats resulted in biomechanical properties of the healed right femur greatly superior to the femur with untreated critical-sized diaphyseal defect by sixteenth week post-surgery and was only slightly inferior to the normal intact left femur. The results were suggestive of using biphasic hydroxyapatite and β-tricalcium phosphate bioceramics scaffolds as a safe and promising alternative for the treatment of critical-sized bone defects Keywords: Beta-tricalcium phosphate, bioceramic scaffold, compression test, hydroxyapatite, three-point bending test and torsion test

3D-Printable Biopolymers for Socket Preservation Technique: Soft Tissues Response: A Pilot Randomised Clinical Study.

The aim of the present parallel clinical study is to evaluate the efficacy of 3D-printed biopolymers compounded with osteoconductive material (beta-tricalcium phosphate and hydroxyapatite) for soft tissue closure after tooth extraction. this study followed the CONSORT reporting guidelines; 39 patients were treated with socket preservation using 3D-printed biopolymers and randomly divided into 3 groups (Test 1, Test 2, and Control). All cases were treated without flap elevation, careful cleaning and debridement of the sites, and then randomly sealed as follows: In T1, with a 3D-printed disk of poli-D-lactic acid with 10% of hydroxyapatite; in T2, using a 3D-printed disk of poli-ε caprolactone with 20% of β-tricalcium phosphate; and in T3, the socket was left open to heal. At baseline (extraction time) and 6 weeks after extraction, the rate of exposure was evaluated and stratified according to the site (anterior, posterior). No dropouts were observed during the 6 weeks follow-up. All sites underwent uneventful healing with no complications. For posterior teeth, Test 1 and Test 2 showed full healing of the soft tissues with a reduction of the exposed area from 46.5 ± 8.25 mm2 to 0.6 ± 0.84 mm2 and from 47.1 ± 8.67 mm2 to 0.6 ± 0.7 mm2, respectively. The Control group exhibited a reduction from 45.6 ± 7.25 mm2 to 1.2 ± 0.9 mm2. Both Tests 1 and 2, when compared to the Control group, showed statistically significant better healing (p < 0.05). Anterior teeth showed a complete closure of the socket 4 weeks after the extraction with no noticeable differences between Test and Control. Both materials used in this study showed evidence to achieve the purpose. Ethical Guidelines: written informed consent was obtained from the participants of the study, as requested by the Ethics Committee for Health Research Faculty of Dentistry, Universitas Trisakti, with the following number: 641/S3/KEPK/FKG/5/2023.

Methods to Enhance Mechanical Strength of 3D Printed Chitosan Scaffolds for Jawbone Regeneration

Current jaw reconstruction methods using autografts and allografts have limitations such as donor site morbidity, limited bone volume, and immunological rejection. As opposed to surgical methods synthetic biomaterials are used however they often fall short in providing the optimal combination of biocompatibility, mechanical strength, and customizable design required for effective jawbone reconstruction. 3D-printed chitosan scaffolds offer a promising alternative due to their biocompatibility, ease of customization, and potential for improved mechanical strength. This review explores strategies to optimize 3D-printed chitosan scaffolds for jaw reconstruction. We examine ways to increase their mechanical strength without compromising biocompatibility, with a particular emphasis on chemical modifications such as hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) cross-linking and chitosan polyelectrolyte complex formation. We also discuss the critical roles that 3D printing processes (FDM and SLA) and intrinsic chitosan qualities (degree of deacetylation) play in making an ink printable. Optimizing 3D printing methods for chitosan-ceramic composites and exploring biocompatible additives to enhance printability are identified as key areas for further research. By addressing these challenges, 3D-printed chitosan scaffolds have the potential to become next-generation biomaterials for jaw reconstruction, revolutionizing the field through precise anatomical adaptation, enhanced osteoconductivity, controlled biodegradation, and the capacity for incorporating bioactive molecules, ultimately leading to accelerated bone regeneration and improved functional and aesthetic outcomes.

Repairing Dehiscence Defects at Implant Sites using β-Tricalcium Phosphate/Calcium Sulfate versus Xenograft Combined With Membrane: A Randomized Clinical Trial.

Guided bone regeneration (GBR) typically involves bone grafts and a membrane to enhance bone formation. Beta-tricalcium phosphate calcium sulfate (β-TCP/CS) is a novel material with self-hardening and tissue growth inhibition properties and can potentially replace the need for a membrane. This study compares β-TricalciumPhosphate/CalciumSulfate with deproteinized bovine bone mineral and a collagen membrane (DBBM/CM) to repair bone defects at implant sites over six months. Sixteen implant defects were divided into β-TCP/CS (n = 8) and DBBM/CM (n = 8). The results showed no significant differences in vertical and horizontal defect fill in millimeters between β-TCP/CS (2.87±1.25 and 2.37±1.06 mm., respectively) and DBBM/CM (3.5±0.92 and 2.87±1.12 mm. , respectively). Buccal bone thickness (BT) alterations at the implant platform levels (BT0) were similar for both materials. However, β-TCP/CS exhibited greater bone alteration at the 2-mm level (BT2: -1.85 mm vs. -0.47 mm) and 4-mm level (BT4: -1.79 mm vs. 0.12 mm) apical to the implant platform compared to DBBM/CM. When assessing volume alteration, β-TCP/CS showed a significantly greater reduction at the platform to the 2 mm level (-61.98% vs. -23.76%) than DBBM/CM. In conclusion, β-TCP/CS demonstrated promise for treating buccal bone defects around implants but exhibited higher graft reduction. This suggests that while β-TricalciumPhosphate/CalciumSulfate may offer clinical benefits, its potential for greater graft reduction should be considered. Further research and evaluation are warranted to fully understand the long-term implications of using β-TCP/CS in guided bone regeneration procedures.

Enhanced Sinterability and Mechanical Strength of Beta-type Tricalcium Phosphates Ceramics through Reaction Sintering with Hydroxyapatite

Beta-tricalcium phosphate (β-TCP) ceramics were fabricated via reaction sintering at 1100 °C, utilizing various phosphate salts and calcium compounds as raw materials. The sintering characteristics, reaction sintering behavior and mechanical properties of the resulting β-TCP ceramics were investigated. Reaction sintering with a Ca/P molar ratio of 1.50 consistently generated β-TCP. In addition, a notable variance in physical properties was observed contingent on the presence or absence of stoichiometric hydroxyapatite (HAp; Ca10(PO4)6(OH)2) in raw materials. Sintered bodies produced with HAp−β-Ca2P2O7 (β-CPP), HAp− CaHPO4·2H2O (DCPD) and HAp−(NH4)2H(PO4) all exhibited densification and enhanced mechanical strength, correlated with higher bulk densities. In contrast, conventional sintered bodies prepared from β-TCP and reaction sintered bodies prepared using β-CPP−Ca(OH)2 or β-CPP−CaCO3 were not as dense. Comprehensive assessments by thermogravimetry-differential thermal analysis, X-ray diffraction and scanning electron microscope together with the evaluation of shrinkage behavior were used to monitor the sintering of β-TCP with HAp. This process was found to involve thermal decomposition of HAp and crystal transitions leading to the formation and sintering of β-TCP with significant shrinkage. These findings underscore the efficacy of employing HAp as a raw material in reaction sintering. This technique allows the formation of sintered β-TCP bodies exhibiting exceptional sintering characteristics, superior bulk density and high mechanical strength.

Radiographic Tibial Tunnel Assessment After Anterior Cruciate Ligament Reconstruction Using Hamstring Tendon Autografts and Biocomposite Screws: A Prospective Study With 10-Year Follow-up.

Biocomposite screws reportedly provide equivalent graft fixation in anterior cruciate ligament reconstruction (ACLR) to metallic screws while simplifying subsequent imaging and surgery. One purported complication of biocomposite screws is paradoxical tunnel widening. Previous studies on beta-tricalcium phosphate screws have only reported outcomes at short- and midterm follow-up. To radiographically assess the tibial tunnel 10 years after ACLR using hamstring tendon autografts and biocomposite interference screws in anatomic single-bundle (SB) and double-bundle (DB) methods. Case series; Level of evidence, 4. Of the 105 initially recruited patients, 61 (58%) completed all follow-up evaluations for inclusion in this long-term study. A total of 26 patients received anatomic SB ACLR and 35 patients received DB ACLR with biocomposite interference screws containing beta-tricalcium phosphate in the tibia. Weightbearing anteroposterior and lateral radiographs of the index knee were taken in the early postoperative period and at 2, 5, and 10 years postoperatively; computed tomography (CT) imaging was performed at 10-year follow-up. Subjective and objective clinical assessments were recorded preoperatively and at 10-year follow-up. The mean follow-up period was 122 months. In 76% of radiographs in the SB group, the width of the tibial tunnel had not increased at 10 years compared with the early postoperative period. The mean tibial tunnel volume on CT in the SB group was 2.04 cm3 (± 0.85 cm3). In the DB group, the posterolateral tunnel width had not increased in 69% of radiographs; the same was found in 63% of radiographs for the anteromedial tunnel at 10-year follow-up. The mean posterolateral tunnel volume on CT was 2.04 cm3 (±1.92 cm3) and the mean anteromedial tunnel volume was 1.38 cm3 (±0.54 cm3). There was no correlation between tunnel widths and KT-1000 arthrometer assessments. There was a moderate but statistically significant correlation between SB tibial tunnel volume on CT imaging and KT-1000 arthrometer anterior 134 N side-to-side difference (r = 0.45; P = .039). Most patients' tibial tunnels had not increased on 1 or both radiographic views at 10-year follow-up compared with the early postoperative period after ACLR using biocomposite interference screws, with no obvious negative effect on outcomes. However, the tunnels were still visible in most patients at 10 years on standard radiographs and CT imaging.

Primary Stability and Osseointegration of the Implant in an Iatrogenically Oversized Cavity by Bone Substitute: An Animal Study

Background: The aim of this study was to compare the success rate of autogenous bone and combination of autogenous bone and beta-tricalcium phosphate (β-TCP) grafts in restoring the primary stability and osseointegration of dental implants after the oversized preparation of the bone cavity in animal models. Methods: Three months after extracting 3 premolars from 4 male Terrier dogs, 24 implants were inserted in cavities larger than the fixture size. Then, based on the type of graft materials around the implant fixture, they were randomly divided into the autogenous bone group (A, n=8), the autogenous bone group with β-TCP (B, n=8), and the control group with no grafts (C, n=8). After 16 weeks, the removal torque quantity (RTQ) test and Periotest® were used for osseointegration assessment. Results: According to the results of the RTQ test, group B was significantly higher than group C (P=0.022), but no statistical difference was observed between groups A and B, as well as groups A and C. Based on the results, the Periotest® value significantly differed in group B compared to groups A (P=0.049) and C (P=0.014), but there was no difference between groups A and C in this regard. Conclusions: According to the findings of the study, the combination of autogenous bone graft and TCP could improve secondary stability and osseointegration of dental implants.

Zinc and chitosan-enhanced β-tricalcium phosphate from calcined fetal bovine bone for mandible reconstruction.

Mandibular defects pose significant challenges in reconstructive surgery, and scaffold materials are increasingly recognized for their potential to address these challenges. Among various scaffold materials, Beta-tricalcium phosphate (β-TCP) is noted for its exceptional osteogenic properties. However, improvements in its biodegradation rate and mechanical strength are essential for optimal performance. In this study, we developed a novel β-TCP-based scaffold, CFBB, by calcining fetal bovine cancellous bone. To enhance its properties, we modified CFBB with Chitosan (CS) and Zinc (Zn), creating three additional scaffold materials: CFBB/CS, CFBB/Zn2+, and CFBB/Zn2+/CS. We conducted comprehensive assessments of their physicochemical and morphological properties, degradation rates, biocompatibility, osteogenic ability, new bone formation, and neovascularization both in vitro and in vivo. Our findings revealed that all four materials were biocompatible and safe for use. The modifications with CS and Zn2+ significantly improved the mechanical strength, osteogenic, and angiogenic properties of CFBB, while concurrently decelerating its resorption rate. Among the tested materials, CFBB/Zn2+/CS demonstrated superior performance in promoting bone regeneration and vascularization, making it a particularly promising candidate for mandibular reconstruction. The CFBB/Zn2+/CS scaffold material, with its enhanced mechanical, osteogenic, and angiogenic properties, and a controlled resorption rate, emerges as a highly effective alternative for the repair of oral mandible defects. This study underscores the potential of combining multiple bioactive agents in scaffold materials to improve their functionality for specific clinical applications in bone tissue engineering.

Effect of addition of varying percentages of barium titanate on the properties of beta-tricalcium phosphate

Effect of addition of varying percentages of barium titanate on the properties of beta-tricalcium phosphate

Combined use of PRPP, diode laser and piezosurgery device improves reparative osteogenesis previously to dental implants placement

ObjectiveCurrent study evaluated whether use of the platelet-rich powder (PRPP), piezosurgery device and diode laser after removal of jawbones cysts and benign bone formations and extraction of impacted tooth could enhance bone regeneration before dental implantation. MethodsA study was conducted among 200 patients with post-surgical cavities (not exceeding 1.5 cm upon cystectomy, benign bone tumor removal and impacted tooth extraction) who underwent plasma powder, autograft, allograft, xenograft or beta-tricalcium phosphate augmentation procedures. ResultsPRPP implantation in combination with irradiation of bone cavity by diode laser led to the formation of 15.40 % ± 2.1 of new bone. The activity of reparative osteogenesis on the bone surface was BB = 6.71 ± 1.3, which is 3 and 3.5 times higher than the mean value in comparison group after augmentation of xenograft and beta-tricalcium phosphate. The value of bone tissue resorption for main group patients was less pronounced (Ra.Oc = 25.20 % ± 2.1).The ratio between pro- and anti-inflammatory cytokines in the main group after 1, 7 and 30 days since surgical procedure was lower than the ratio of the corresponding cytokines in the comparison groups. ConclusionThe examination of computed tomograms, histological and morphometric analysis of bone tissue after trepanobiopsy, cytological analysis of swabs and enzyme immunoassay to determine local immunity indicated that the proposed method of treatment with the use of PRPP, the piezosurgery device and the diode laser has a positive effect: it helped to optimize reparative osteogenesis after filling post-surgical cavities and restore bone volume.

The Effects of Putty and Granule Beta-tricalcium Phosphate on Bone Cell Histomorphometry and Ki67 Expression in Sheep Tibia

The Effects of Putty and Granule Beta-tricalcium Phosphate on Bone Cell Histomorphometry and Ki67 Expression in Sheep Tibia

3D-bioprinted poly(lactic acid)/β-TCP/mesoporous silica scaffolds: An investigation on in-vitro bioactivity and osteogenesis characteristics

The current work aims to formulate novel bioactive and biocompatible 3D printed poly (l-lactic acid)/Beta tri calcium phosphate composite scaffolds reinforced with different types of mesoporous silica materials [PLA/β-TCP/MSMs] for bone regeneration application, which is not envisaged earlier. The bioink encompassing 30 % organic content (PLA) and 70 % inorganic content (β-TCP and MSMs) is formulated and their rheological characteristics are evaluated. Optimization of process conditions for 3D printed PLA composite scaffolds was done and pneumatic extrusion is performed. The physico-chemical properties as well as in vitro biological characteristics were assessed for 3D printed PLA/β-TCP/MSMs based composite scaffolds. The existence of β-TCP and MSMs incorporated into PLA matrix was observed to fasten the formation of hydroxyapatite, as evidenced by in vitro bioactivity assessment. The in vitro cytocompatibility analysis revealed that the 3D printed PLA/β-TCP/MSMs composite scaffolds exhibit suitable biocompatible behaviour and osteogenic potential. The calcium mineralization and ALP expression were also noticed in higher levels for 3D printed PLA/β-TCP/MSMs composite scaffolds. Gene expression analysis confirmed the expression of COL1, OCN, BMP-2 and RUNX2 on 3D printed PLA/β-TCP/MSMs composite scaffolds. The results speculate that this novel formulation closely resembling the composition of natural bone might have promising applications in terms of in vivo bone tissue engineering.

Reinforcing β-tricalcium phosphate scaffolds for potential applications in bone tissue engineering: impact of functionalized multi-walled carbon nanotubes

Beta-tricalcium phosphate (β-TCP) scaffolds manufactured through the foam replication method are widely employed in bone tissue regeneration. The mechanical strength of these scaffolds is a significant challenge, partly due to the rheological properties of the original suspension. Various strategies have been explored to enhance the mechanical properties. In this research, β-TCP scaffolds containing varying concentrations (0.25–1.00 wt%) of multi-walled carbon nanotubes (MWCNT) were developed. The findings indicate that the addition of MWCNTs led to a concentration-dependent improvement in the viscosity of β-TCP suspensions. All the prepared slurries exhibited viscoelastic behavior, with the storage modulus surpassing the loss modulus. The three time interval tests revealed that MWCNT-incorporated β-TCP suspensions exhibited faster structural recovery compared to pure β-TCP slurries. Introducing MWCNT modified compressive strength, and the optimal improvement was obtained using 0.75 wt% MWCNT. The in vitro degradation of β-TCP was also reduced by incorporating MWCNT. While the inclusion of carbon nanotubes had a marginal negative impact on the viability and attachment of MC3T3-E1 cells, the number of viable cells remained above 70% of the control group. Additionally, the results demonstrated that the scaffold increased the expression level of osteocalcin, osteoponthin, and alkaline phosphatase genes of adiposed-derived stem cells; however, higher levels of gene expersion were obtained by using MWCNT. The suitability of MWCNT-modified β-TCP suspensions for the foam replication method can be assessed by evaluating their rheological behavior, aiding in determining the critical additive concentration necessary for a successful coating process.

Risk factors for delayed bone union in opening wedge high tibial osteotomy.

The purpose of this study was to investigate the relationship between patient demographics and potential intraoperative factors and delayed bone union in opening wedge high tibial osteotomy (OWHTO). A retrospective review of 65 patients (37 females, 28 males; mean age: 60.1±10.1 years; range, 44 to 77 years) who underwent OWHTO using an angle-stable implant with beta-tricalcium phosphate gap filling between September 2016 and October 2019 was conducted. The osteotomy site was divided into five zones from the lateral hinge on anteroposterior radiographs, and we defined the zone in which bone healing was observed. The bone union area was assessed according to this definition at three, six, nine, and 12 months after surgery, and bone union was defined as union at the fourth zone or greater. A generalized estimating equations approach was employed to investigate longitudinal data pertaining to bone union area as a dependent variable. In addition, the association of bone union at six months postoperatively and predictors were evaluated using cross-sectional statistical methods. The categorical predictors included in the models were smoking, diabetes, hinge fracture, and autologous osteophyte grafting. The continuous variables included in the models were age, body mass index, opening gap width, and plate position. Smoking (odds ratio [OR]=0.478, p<0.01), large opening gap width (OR=0.941, p=0.014), and anterior plate placement (OR=0.971, p<0.01) were significantly associated with decreased bone union area. Union rate at six months in smokers was significantly lower compared to nonsmokers (16.6% and 67.8%, respectively; OR=0.10, p=0.023). Area under the curve in the receiver operating characteristic analysis for bone union at six months was 0.60 for gap width and 0.63 for plate placement. Smoking, large opening gap width, and anterior plate placement are risk factors for delayed bone union after OWHTO. Surgeons should avoid anterior placement of the plate and carefully consider other options for smokers and those who require a large correction.

Effect of the Addition of Inorganic Fillers on the Properties of Degradable Polymeric Blends for Bone Tissue Engineering.

Bone tissue exhibits self-healing properties; however, not all defects can be repaired without surgical intervention. Bone tissue engineering offers artificial scaffolds, which can act as a temporary matrix for bone regeneration. The aim of this study was to manufacture scaffolds made of poly(lactic acid), poly(ε-caprolactone), poly(propylene fumarate), and poly(ethylene glycol) modified with bioglass, beta tricalcium phosphate (TCP), and/or wollastonite (W) particles. The scaffolds were fabricated using a gel-casting method and observed with optical and scanning electron microscopes. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR), differential scanning calorimetry (DSC), thermogravimetry (TG), wettability, and degradation tests were conducted. The highest content of TCP without W in the composition caused the highest hydrophilicity (water contact angle of 61.9 ± 6.3°), the fastest degradation rate (7% mass loss within 28 days), moderate ability to precipitate CaP after incubation in PBS, and no cytotoxicity for L929 cells. The highest content of W without TCP caused the highest hydrophobicity (water contact angle of 83.4 ± 1.7°), the lowest thermal stability, slower degradation (3% mass loss within 28 days), and did not evoke CaP precipitation. Moreover, some signs of cytotoxicity on day 1 were observed. The samples with both TCP and W showed moderate properties and the best cytocompatibility on day 4. Interestingly, they were covered with typical cauliflower-like hydroxyapatite deposits after incubation in phosphate-buffered saline (PBS), which might be a sign of their excellent bioactivity.

Physicochemical characterization of experimental resin-based materials containing calcium orthophosphates or calcium silicate

ObjectiveTo evaluate experimental dimethacrylate-based materials containing calcium orthophosphates or calcium silicate particles in terms of their optical, mechanical and Ca2+ release behaviour. MethodsDicalcium phosphate dihydrate (DCPD), hydroxyapatite (HAp), beta-tricalcium phosphate (β-TCP) or calcium silicate (CaSi) particles were added to a photocurable BisGMA/TEGDMA resin (1:1 in mols) at a 30 vol% fraction. Materials containing silanized or non-silanized barium glass particles were used as controls. Degree of conversion (DC) at the top and base of 2-mm thick specimens was determined by ATR-FTIR spectroscopy (n = 5). Translucency parameter (TP) and transmittance (%T) were determined using a spectrophotometer (n = 3). Biaxial flexural strength (BFS) and flexural modulus (FM) were determined by biaxial flexural testing after 24 h storage in water (n = 10). Ca2+ release in water was determined during 28 days by inductively coupled plasma optical emission spectrometry (n = 3). Statistical analysis was performed using ANOVA/Tukey test (DC: two-way; TP, %T; BFS and FM: one-way; Ca2+ release: repeated measures two-way, α = 5 %). Results: CaSi and β-TCP particles drastically reduced DC at 2 mm, TP and %T (p < 0.001). Compared to both controls, all Ca2+-releasing materials presented lower BFS (p < 0.001) and only the material with DCPD showed significantly lower FM (p < 0.05). The material containing CaSi presented the highest Ca2+ release, while among materials formulated with calcium orthophosphates the use of DCPD resulted in the highest release (p < 0.001). SignificanceCaSi particles allowed the highest Ca2+ release. Notwithstanding, the use of DCPD resulted in a material with the best compromise between optical behaviour, DC, strength and Ca2+ release.

A detailed methodology for a three-dimensional, self-structuring bone model that supports the differentiation of osteoblasts towards osteocytes and the production of a complex collagen-rich mineralised matrix

Background There are insufficient in vitro bone models that accommodate long-term culture of osteoblasts and support their differentiation to osteocytes. The increased demand for effective therapies for bone diseases, and the ethical requirement to replace animals in research, warrants the development of such models. Here we present an in-depth protocol to prepare, create and maintain three-dimensional, in vitro, self-structuring bone models that support osteocytogenesis and long-term osteoblast survival (&gt;1 year). Methods Osteoblastic cells are seeded on a fibrin hydrogel, cast between two beta-tricalcium phosphate anchors. Analytical methods optimised for these self-structuring bone model (SSBM) constructs, including RT-qPCR, immunofluorescence staining and XRF, are described in detail. Results Over time, the cells restructure and replace the initial matrix with a collagen-rich, mineralising one; and demonstrate differentiation towards osteocytes within 12 weeks of culture. Conclusions Whilst optimised using a secondary human cell line (hFOB 1.19), this protocol readily accommodates osteoblasts from other species (rat and mouse) and origins (primary and secondary). This simple, straightforward method creates reproducible in vitro bone models that are responsive to exogenous stimuli, offering a versatile platform for conducting preclinical translatable research studies.

Fabrication Strategies for Bioceramic Scaffolds in Bone Tissue Engineering with Generative Design Applications.

The aim of this study is to provide an overview of the current state-of-the-art in the fabrication of bioceramic scaffolds for bone tissue engineering, with an emphasis on the use of three-dimensional (3D) technologies coupled with generative design principles. The field of modern medicine has witnessed remarkable advancements and continuous innovation in recent decades, driven by a relentless desire to improve patient outcomes and quality of life. Central to this progress is the field of tissue engineering, which holds immense promise for regenerative medicine applications. Scaffolds are integral to tissue engineering and serve as 3D frameworks that support cell attachment, proliferation, and differentiation. A wide array of materials has been explored for the fabrication of scaffolds, including bioceramics (i.e., hydroxyapatite, beta-tricalcium phosphate, bioglasses) and bioceramic-polymer composites, each offering unique properties and functionalities tailored to specific applications. Several fabrication methods, such as thermal-induced phase separation, electrospinning, freeze-drying, gas foaming, particle leaching/solvent casting, fused deposition modeling, 3D printing, stereolithography and selective laser sintering, will be introduced and thoroughly analyzed and discussed from the point of view of their unique characteristics, which have proven invaluable for obtaining bioceramic scaffolds. Moreover, by highlighting the important role of generative design in scaffold optimization, this review seeks to pave the way for the development of innovative strategies and personalized solutions to address significant gaps in the current literature, mainly related to complex bone defects in bone tissue engineering.

A 3D bioreactor model to study osteocyte differentiation and mechanobiology under perfusion and compressive mechanical loading

Osteocytes perceive and process mechanical stimuli in the lacuno-canalicular network in bone. As a result, they secrete signaling molecules that mediate bone formation and resorption. To date, few three-dimensional (3D) models exist to study the response of mature osteocytes to biophysical stimuli that mimic fluid shear stress and substrate strain in a mineralized, biomimetic bone-like environment. Here we established a biomimetic 3D bone model by utilizing a state-of-art perfusion bioreactor platform where immortomouse/Dmp1-GFP-derived osteoblastic IDG-SW3 cells were differentiated into mature osteocytes. We evaluated proliferation and differentiation properties of the cells on 3D microporous scaffolds of decellularized bone (dBone), poly(L-lactide-co-trimethylene carbonate) lactide (LTMC), and beta-tricalcium phosphate (β-TCP) under physiological fluid flow conditions over 21 days. Osteocyte viability and proliferation were similar on the scaffolds with equal distribution of IDG-SW3 cells on dBone and LTMC scaffolds. After seven days, the differentiation marker alkaline phosphatase (Alpl), dentin matrix acidic phosphoprotein 1 (Dmp1), and sclerostin (Sost) were significantly upregulated in IDG-SW3 cells (p = 0.05) on LTMC scaffolds under fluid flow conditions at 1.7 ml/min, indicating rapid and efficient maturation into osteocytes. Osteocytes responded by inducing the mechanoresponsive genes FBJ osteosarcoma oncogene (Fos) and prostaglandin-endoperoxide synthase 2 (Ptgs2) under perfusion and dynamic compressive loading at 1 Hz with 5 % strain. Together, we successfully created a 3D biomimetic platform as a robust tool to evaluate osteocyte differentiation and mechanobiology in vitro while recapitulating in vivo mechanical cues such as fluid flow within the lacuno-canalicular network. Statement of significanceThis study highlights the importance of creating a three-dimensional (3D) in vitro model to study osteocyte differentiation and mechanobiology, as cellular functions are limited in two-dimensional (2D) models lacking in vivo tissue organization. By using a perfusion bioreactor platform, physiological conditions of fluid flow and compressive loading were mimicked to which osteocytes are exposed in vivo. Microporous poly(L-lactide-co-trimethylene carbonate) lactide (LTMC) scaffolds in 3D are identified as a valuable tool to create a favorable environment for osteocyte differentiation and to enable mechanical stimulation of osteocytes by perfusion and compressive loading. The LTMC platform imitates the mechanical bone environment of osteocytes, allowing the analysis of the interaction with other cell types in bone under in vivo biophysical stimuli.