Synthetic Bone Graft Research Articles

Biological knee joint reconstruction using patella following giant cell tumor excision: a case report

A 20-year-old female patient presented to us with a large expansile swelling over right knee diagnosed clinically and confirmed histopathological and radiologically to be Giant Cell Tumor of upper end of Tibia involving both condyles with a breach in the posterior cortex. In this case report we tried to retain the joint function by biological reconstruction using the Patella after the wide excision of the tumor mass. A radical excision of the upper end of the Tibia was done. The Patella was used as an articular surface supported by ipsilateral Fibula and cortico-cancellous bone chips from the ipsilateral iliac crest as struts and complemented with synthetic bone graft pieces. Thus, the joint was reconstructed biologically. The case was followed for 1 year. The tumor was excised in toto, the knee joint was restored by the Patella and the bone graft struts. The results were discussed in detail.

Investigation on structurally reinforced synthetic bone grafts via tricalcium silicate

AbstractTricalcium silicate (C3S) is one of the main components of mineral trioxide aggregates, which is used in dental endodontic treatment. C3S provides workable viscosity itself and fast hydration when water is added, and it is known to be nontoxic, noncarcinogenic, nongenotoxic, biocompatible, and insoluble in tissue fluids. In this study, C3S is added to synthetic bone‐graft materials from 30% to 60% to deliver viscosity to increase workability in the early stage of implant surgical procedure and to attain some degree of compressive strength after the hydration. Additionally, the porosity is not overly reduced to maintain the ability for bone regeneration. The porosity of the samples was confirmed to be 40%–50% with the formation of the C3S matrices. Simultaneously, the maximum compressive strength was ensured at 14.9 MPa within 24 h of curing time. The radiopacity required for post‐procedural diagnosis was evaluated. The radiopacity of the samples with 50% and 60% C3S was 1.0 mm Al and 1.1 mm Al, respectively. When ZrO2 was added, the radiopacity was enhanced to 1.6 mm Al. Overall, the experimental results showed that the bone‐graft added C3S would be suitable for alveolar bone support and rigid matrix formation in implant surgery.

Highly porous polycaprolactone microspheres for skeletal repair promote a mature bone cell phenotype in vitro.

Improving our ability to treat skeletal defects is a critical medical challenge that necessitates the development of new biomaterials. One promising approach involves the use of degradable polymer microparticles with an interconnected internal porosity. Here, we employed a double emulsion to generate such round microparticles (also known as microspheres) from a polycaprolactone-based polymerised high internal phase emulsion (polyHIPE). These microspheres effectively supported the growth of mesenchymal progenitors over a 30-day period, and when maintained in osteogenic media, cells deposited a bone-like extracellular matrix, as determined by histological staining for calcium and collagen. Interestingly, cells with an osteocyte-like morphology were observed within the core of the microspheres indicating the role of a physical environment comparable to native bone for this phenotype to occur. At later timepoints, these cultures had significantly increased mRNA expression of the osteocyte-specific markers dentin matrix phosphoprotein-1 (Dmp-1) and sclerostin, with sclerostin also observed at the protein level. Cells pre-cultured on porous microspheres exhibited enhanced survival rates compared to those pre-cultured on non-porous counterparts when injected. Cells precultured on both porous and non-porous microspheres promoted angiogenesis in a chorioallantoic membrane (CAM) assay. In summary, the polycaprolactone polyHIPE microspheres developed in this study exhibit significant promise as an alternative to traditional synthetic bone graft substitutes, offering a conducive environment for cell growth and differentiation, with the potential for better clinical outcomes in bone repair and regeneration.

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

Distraction osteogenesis application in bone defect caused by osteomyelitis following mandibular fracture surgery: a case report and literature review

BackgroundOsteomyelitis secondary to mandibular fracture surgery is rare and complete surgical debridement of necrotic infected tissues is an optimal treatment for it. Subsequent reconstruction is required for bone defect caused by operation. Autogenous, allograft and synthetic bone graft substitutes have become widespread in bone defect treatment. Distraction osteogenesis (DO) was also applied in bone defect reconstruction, even it wasn’t conventional therapy in jaw.Case presentationHere we report a case of a 40-year-old aged man who presented with chronic swelling and pain on the right mandibular masseteric region after mandibular angle and Le Fort II fracture surgery. In six weeks after surgery, CBCT images showed that the fracture ends hadn’t heal and the fracture gap had widened significantly. The clinical diagnosis of the patient was right mandibular angle osteomyelitis. After controlling the symptoms of pain and infection with local rinses and systemic antibiotic therapy, the patient underwent segmental resection of the infected bone and DO reconstruction for bone defect simultaneously. Encouragingly, well bone healing and normal occlusion restoration was observed finally.ConclusionsDO could be a valuable alternative therapy to bone grafts for bone defect, even in the case of infection.

An Up-to-Date Review of Materials Science Advances in Bone Grafting for Oral and Maxillofacial Pathology.

Bone grafting in oral and maxillofacial surgery has evolved significantly due to developments in materials science, offering innovative alternatives for the repair of bone defects. A few grafts are currently used in clinical settings, including autografts, xenografts, and allografts. However, despite their benefits, they have some challenges, such as limited availability, the possibility of disease transmission, and lack of personalization for the defect. Synthetic bone grafts have gained attention since they have the potential to overcome these limitations. Moreover, new technologies like nanotechnology, 3D printing, and 3D bioprinting have allowed the incorporation of molecules or substances within grafts to aid in bone repair. The addition of different moieties, such as growth factors, stem cells, and nanomaterials, has been reported to help mimic the natural bone healing process more closely, promoting faster and more complete regeneration. In this regard, this review explores the currently available bone grafts, the possibility of incorporating substances and molecules into their composition to accelerate and improve bone regeneration, and advanced graft manufacturing techniques. Furthermore, the presented current clinical applications and success stories for novel bone grafts emphasize the future potential of synthetic grafts and biomaterial innovations in improving patient outcomes in oral and maxillofacial surgery.

Calcium phosphate complex of recombinant human thrombomodulin promote bone formation in interbody fusion.

Interbody fusion is an orthopedic surgical procedure to connect two adjacent vertebrae in patients suffering from spinal disc disease. The combination of synthetic bone grafts with protein-based drugs is an intriguing approach to stimulate interbody bone growth, specifically in patients exhibiting restricted bone progression. Recombinant human thrombomodulin (rhTM), a novel protein drug characterized by its superior stability and potency, shows promise in enhancing bone formation. A composite bone graft, termed CaP-rhTM, has been synthesized, combining calcium phosphate (CaP) microparticles as a delivery vehicle for rhTM to facilitate interbody fusion. In vitro studies have demonstrated that rhTM significantly promotes the proliferation and maturation of preosteoblasts at nanogram dosage, while exerting minimal impact on osteosarcoma cell growth. The expression levels of mature osteoblast markers, including osteocalcin, osteopontin, alkaline phosphatase, and calcium deposition were also enhanced by rhTM. In rat caudal disc model of interbody fusion, CaP-rhTM with 800 ng of drug doaeage was implanted along with a polylactic acid (PLA) cage, to ensure structural stability within the intervertebral space. Microcomputed tomography analyses revealed that from 8 to 24 weeks, CaP-rhTM substantially improves both bone volume and trabecular architecture, in addition to the textural integrity of bony endplate surfaces. Histological examination confirmed the formation of a continuous bone bridge connecting adjacent vertebrae. Furthermore, biomechanical assessment via three-point bending tests indicated an improved bone quality of the fused disc. This study has demostrated that rhTM exhibits considerable potential in promoting osteogenesis. The use of CaP-rhTM has also shown significant improvements in promoting interbody fusion.

The efficiency of two different synthetic bone graft materials on alveolar ridge preservation after tooth extraction: a split-mouth study

BackgroundAlveolar Bone loss occurs frequently during the first six months after tooth extraction. Various studies have proposed different methods to reduce as much as possible the atrophy of the alveolar ridge after tooth extraction. Filling the socket with biomaterials after extraction can reduce the resorption of the alveolar ridge. We compared the height of the alveolar process at the mesial and distal aspects of the extraction site and the resorption rate was calculated after the application of HA/β-TCP or synthetic co-polymer polyglycolic - polylactic acid PLGA mixed with blood to prevent socket resorption immediately and after tooth extraction.MethodsThe study was conducted on 24 extraction sockets of impacted mandibular third molars bilaterally, vertically, and completely covered, with a thin bony layer. HA/β-TCP was inserted into 12 of the dental sockets immediately after extraction, and the synthetic polymer PLGA was inserted into 12 of the dental sockets. All sockets were covered completely with a full-thickness envelope flap. Follow-up was performed for one year after extraction, using radiographs and stents for the vertical alveolar ridge measurements.ResultsThe mean resorption rate in the HA/β-TCP and PLGA groups was ± 1.23 mm and ± 0.1 mm, respectively. A minimal alveolar bone height reduction of HA/β-TCP was observed after 9 months, the reduction showed a slight decrease to 0.93 mm, while this rate was 0.04 mm after 9 months in the PLGA group. Moreover, the bone height was maintained after three months, indicating a good HA/β-TCP graft performance in preserving alveolar bone (1.04 mm) while this rate was (0.04 mm) for PLGA.ConclusionThe PLGA graft demonstrated adequate safety and efficacy in dental socket preservation following tooth extraction. However, HA/β-TCP causes greater resorption at augmented sites than PLGA, which clinicians should consider during treatment planning.

Paley cross union protocol for congenital pseudoarthrosis of the tibia

<p><strong>Aim</strong> Congenital pseudarthrosis of the tibia (CPT) is a rare, dysplastic condition causing significant disability in the lower limbs. A treatment aims to achieve long-lasting union, prevent limb length discrepancies, and prevent soft tissue lesions. Traditional surgery often yields satisfactory results, but amputation may be proposed in failed cases. This report presents a congenital pseudarthrosis of the tibia and fibula, treated with the Paley cross-union protocol.<br /><strong>Methods </strong>A 15-month-old girl presented with a crook-ed right lower leg at the age of two months, history of a right lower leg fracture at the age of eight months, and pain when moving her leg. She had undergone an initial surgical procedure to maintain tibia alignment with K-Wire insertion and was cast at a private hospital. <br /><strong>Results </strong>The patient's physical examination showed a cast causing limited range of motion, but no tenderness or distal neurovascular issues. The Paley cross-union protocol was performed, involving anterior approach, curettage, and insertion of a titanium intramedullary elastic nail into the tibia. The fracture site area was covered with a meshed periosteum layer and filled with synthetic bone grafts. A long leg cast was performed after the procedure. An imaging examination post-cross-union protocol showed a good result.<br /><strong>Conclusion </strong>Cross-union for CPT represents a paradigm shift in the treatment of this horrible child disease. Given the promising result, the cross-union approach has to be regarded as a fresh criterion for treating CPT.</p>

The effects of physiologically relevant environmental conditions on the mechanical properties of 3D-printed biopolymer nanocomposites

The demand for synthetic bone graft biomaterials has grown in recent years to alleviate the dependence on natural bone grafts and metal prostheses which are associated with significant practical and clinical issues. Biopolymer nanocomposites are a class of materials that display strong potential for these synthetic materials, especially when processed using additive manufacturing technologies. Novel nanocomposite biomaterials capable of masked stereolithography printing have been developed from functionalized plant-based monomers and hydroxyapatite (HA) with mechanical properties exceeding those of commercial bone cements. However, these biomaterials have not been evaluated under relevant physiological conditions. The effects of temperature (room temperature vs. 37 °C) and water absorption on the physical, surface, and mechanical properties of HA-containing biopolymer nanocomposites were investigated. Exposure to relevant conditions led to substantial impacts on material performance, such as significantly reduced mechanical strength and stiffness. For instance, a composite containing 10 vol% HA and functionalized monomers had 26 and 21% reductions in compressive yield strength and elastic modulus, respectively. After 14 days incubation in phosphate buffered saline, the same composition displayed a 62% decrease in compressive yield strength to 28 MPa. This manuscript demonstrates the relevance and importance of evaluating biomaterials under appropriate physiological conditions throughout their development and provides direction for future material development of HA-containing biopolymer nanocomposites.

Quality assessment of regenerated bone in intraosseous and intramuscular scaffolds by spectroscopy and nanoindentation

The efficiency of synthetic bone grafts can be evaluated either in osseous sites, to analyze osteoconduction or ectopically, in intramuscular or subcutaneous sites, to assess osteoinduction. Bone regeneration is usually evaluated in terms of the presence and quantity of newly formed bone, but little information is normally provided on the quality of this bone. Here, we propose a novel approach to evaluate bone quality by the combined use of spectroscopy techniques and nanoindentation. Calcium phosphate scaffolds with different architectures, either foamed or 3D-printed, that were implanted in osseous or intramuscular defects in Beagle dogs for 6 or 12 weeks were analyzed. ATR-FTIR and Raman spectroscopy were performed, and mineral-to-matrix ratio, crystallinity, and mineral and collagen maturity were calculated and mapped for the newly regenerated bone and the mature cortical bone from the same specimen. For all the parameters studied, the newly-formed bone showed lower values than the mature host bone. Hardness and elastic modulus were determined by nanoindentation and, in line with what was observed by spectroscopy, lower values were observed in the regenerated bone than in the cortical bone. While, as expected, all techniques pointed to an increase in the maturity of the newly-formed bone between 6 and 12 weeks, the bone found in the intramuscular samples after 12 weeks presented lower mineralization than the intraosseous counterparts. Moreover, scaffold architecture also played a role in bone maturity, with the foamed scaffolds showing higher mineralization and crystallinity than the 3D-printed scaffolds after 12 weeks.

Bovine-originated xenografts versus synthetic bone grafting materials in lateral maxillary sinus floor augmentation: A systematic review and meta-analysis.

This study aimed to systematically compare the patients undergoing lateral MSFA therapies utilizing bovine-originated xenografts versus varied synthetic bone grafting materials. Pubmed, Scopus, Embase, and Cochrane Library were searched up to April 2023, compensated by a manual search in selected journals. Studies reporting histological outcomes (residual bone graft, newly formed bone, non-mineralized tissue) and clinical outcomes (implant survival, ISQ value) were included. Several analyses were performed, including meta-analysis, sensitivity study, and Egger's regression tests. Sixteen clinical/randomized control trials were included in this systematic review, among which 12 were enrolled in a meta-analysis. The percentage of newly formed bone within the grafted sinuses by hybrid HA/TCP was significantly higher than those by xenografts (WMD 2.85, 95%CI [0.72; 4.99]), but those grafted by pure HA (WMD -1.72, 95%CI [-3.15; -0.29]) or TCP (WMD -7.10, 95%CI [-13.02; -1.17]) were significantly lower than xenograft counterparts. The residual bone graft and non-mineralized tissue yielded by synthetic HA, TCP, and HA/TCP showed no significant differences with the xenograft group. The chemistry of grafted bone substitutes in lateral MSFA influenced the quantity of newly formed bone. Those grafted with hybrid HA/TCP yielded the highest amount of new bone compared to bovine-originated HA. However, this influence was not significant on residual bone graft and non-mineralizedtissue.

Mechanobiological optimization of scaffolds for bone tissue engineering.

Synthetic bone graft scaffolds aim to generate new bone tissue and alleviate the limitations of autografts and allografts. To meet that aim, it is essential to have a design approach able to generate scaffold architectures that will promote bone formation. Here, we present a topology-varying design optimization method, the "mixed-topology" approach, that generates new designs from a set of starting structures. This approach was used with objective functions focusing on improving the scaffold's local mechanical microenvironments to mechanobiologically promote bone formation within the scaffold and constraints to ensure manufacturability and achieve desired macroscale properties. The results demonstrate that this approach can successfully generate scaffold designs with improved microenvironments, taking into account different combinations of relevant stimuli and constraints.

Opportunity of the Effect of Injectable Platelet Rich Fibrin (I-PRF) Mixed with Bone Graft on the Correlation Between Dental Implant Stability and Alveolar Ridge Width. A Clinical Comparative Study

The potential impact of injectable platelet-rich fibrin (I-PRF) combined with bone graft as a guided bone regeneration on the relationship between dental implant stability, alveolar ridge width, and dental implant dimension. Materials and methods: The present prospective comparative study was registered at ClinicalTrials.gov (ID number: NCT05427643). A total of 13 patients aged 18-65 years (11 females and 2 males) presented with missing teeth in either the maxilla or the mandible or both and met the eligibility criteria and enrolled in this study treated with 40 dental implants. These cases were allocated into two groups, control group in which the implants were placed without I-PRF and a study group (advanced cases with narrow alveolar ridge) in which implants were installed with I-PRF mixed with synthetic bone graft at the dehiscence sites around the implants. 22 (55%) dental implants were inserted in patients with alveolar bone width of ˂ 3.5 mm and 18 (45%) dental implants were inserted in ridge with ≥ 3.5 mm. The primary stability was measured at the time of surgery and Secondary stability was measured 24 weeks after dental implant installation with Anycheck device in implant stability test (IST) values. Results: Twenty dental implants were installed in each study group. According to the results obtained in this study, there was significant difference between primary stability (69.96±8.5 vs 74.50±4.3) of both groups and secondary stability (69.96±8.5 vs 76.32±6.5) values of group A with bone width of ≥ 3.5 mm and dental implant dimension 4.1 mm. Conclusion: The addition of I-PRF with bone graft for augmentation of dehiscence and fenestration peri-implant defects with simultaneous implant placement results in 100% survival rate with statistical differences in implant secondary stability between study groups. However, the results were clinically irrelevant.

The Osteogenic Peptide P-15 for Bone Regeneration: A Narrative Review of the Evidence for a Mechanism of Action.

Bone regeneration is a complex multicellular process involving the recruitment and attachment of osteoprogenitors and their subsequent differentiation into osteoblasts that deposit extracellular matrixes. There is a growing demand for synthetic bone graft materials that can be used to augment these processes to enhance the healing of bone defects resulting from trauma, disease or surgery. P-15 is a small synthetic peptide that is identical in sequence to the cell-binding domain of type I collagen and has been extensively demonstrated in vitro and in vivo to enhance the adhesion, differentiation and proliferation of stem cells involved in bone formation. These events can be categorized into three phases: attachment, activation and amplification. This narrative review summarizes the large body of preclinical research on P-15 in terms of these phases to describe the mechanism of action by which P-15 improves bone formation. Knowledge of this mechanism of action will help to inform the use of P-15 in clinical practice as well as the development of methods of delivering P-15 that optimize clinical outcomes.

The Role of Bone Grafting in Corrective Osteotomy of Distal Radius Malunions

Abstract Background It remains unclear whether bone grafting is required during corrective osteotomy of the distal radius. The goal of this systematic review is to determine the union, revision, and complication rates of bone grafting techniques associated with extra-articular corrective osteotomy for dorsally malunited distal radius fractures treated with volar plating. Questions Is bone grafting in distal radius corrective osteotomy associated with increased rates of bone union and reduced rates of revision surgery and complications? Methods A comprehensive search of the MEDLINE, Embase, and Cumulative Index to Nursing and Allied Health Literature databases was completed for studies reporting clinical outcomes of extra-articular corrective osteotomy for dorsally malunited distal radius fractures treated with volar plating. Results A total of 13 studies, with 14 intervention arms and 236 patients, were included. Bone grafting techniques consisted of autograft (6 studies, n = 93), synthetic bone grafts (2 studies, n = 38), allograft (1 study, n = 14), or no grafting (5 studies, n = 91). The overall union rate was 97%, and the mean time-to-union was 12.0 weeks. Larger corrections of dorsal tilt and ulnar variance were performed in the autograft and allograft groups. Complication and revision rates were highest in the synthetic group, 45 and 26.3% respectively. Conclusion Grafting in extra-articular corrective osteotomy for dorsally angulated distal radius malunions treated with volar plating is not associated with an improved union rate in the literature. However, larger corrections were achieved in both the autograft and allograft groups compared to the no-graft and synthetic groups, resulting in similar union rates. Synthetic bone grafting was associated with the highest complication and revision rates. Future comparative prospective trials and proper documentation of whether cortical contact was present or absent are required to assess whether bone grafting warrants consideration in more advanced deformities. Level of Evidence IV.

Ultrasonic Coating of Poly(D,L-lactic acid)/Poly(lactic-co-glycolic acid) Electrospun Fibers with ZnO Nanoparticles to Increase Angiogenesis in the CAM Assay.

Critical-size bone defects necessitate bone void fillers that should be integrated well and be easily vascularized. One viable option is to use a biocompatible synthetic polymer and sonocoat it with zinc oxide (ZnO) nanoparticles (NPs). However, the ideal NP concentration and size must be assessed because a high dose of ZnO NPs may be toxic. Electrospun PDLLA/PLGA scaffolds were produced with different concentrations (0.5 or 1.0 s of sonocoating) and sizes of ZnO NPs (25 nm and 70 nm). They were characterized by SEM, EDX, ICP-OES, and the water contact angle. Vascularization and integration into the surrounding tissue were assessed with the CAM assay in the living chicken embryo. SEM, EDX, and ICP-OES confirmed the presence of ZnO NPs on polymer fibers. Sonocoated ZnO NPs lowered the WCA compared with the control. Smaller NPs were more pro-angiogenic exhibiting a higher vessel density than the larger NPs. At a lower concentration, less but larger vessels were visible in an environment with a lower cell density. Hence, the favored combination of smaller ZnO NPs at a lower concentration sonocoated on PDLLA/PLGA electrospun meshes leads to an advanced state of tissue integration and vascularization, providing a valuable synthetic bone graft to be used in clinics in the future.

Outcomes of Autologous and Synthetic Bone Grafts in Locking Plate Fixation of Comminuted Distal Radius Fractures.

Background The introduction of locking plate technology has improved the feasibility of distal radius fracture fixation without the need for bone grafting, yet challenges persist in cases of severely comminuted fractures and small, unstable intra-articular fragments. This study aimed to assess the outcomes of bone grafting in severely comminuted distal radius fractures treated with locking plates. Methods We performed a retrospective analysis involving 450 patients who underwent distal radius fracture fixations. We evaluated wrist motion, grip strength, and radiographic parameters, including radial inclination, radial tilt, ulnar variance, articular step, and fracture union at standardized intervals. In addition, at the 12- and 24-month marks, we assessed the disabilities of the arm, shoulder, and hand (DASH) questionnaire score. Results Out of the 450 patients who underwent distal radius fracture fixation using volar locking plate systems, 59 individuals (13%) required either autologous bone graft (n = 24) or synthetic bone substitutes (n = 35). In the final follow-up, all fractures had successfully united, displaying an average volar tilt of 4°, radial inclination of 18.8°, and an articular step or gap of 0.1 mm. Conclusion There was no significant difference between the use of autologous or synthetic bone grafts on clinical or radiological outcomes in the long term. Bone grafts are useful in severe metaphyseal comminutionand aid in the reduction of articular fragments and bi-cortical comminution.

Hindrances and solutions on the path towards adjoined barium titanate–hydroxyapatite ceramics with uncompromised piezoelectric and biological responses

The synergistic piezoelectric and osteoconductive properties of barium titanate (BT) and hydroxyapatite (HA) could stir the development of a new generation of synthetic bone graft substitutes, with capability for rapid and safe osseointegration. The research focused on two concurrent approaches for coupling the BT and HA materials: (i) conventional sintering of BT-HA powder mixtures; and (ii) functionalization of pre-sintered BT with HA coatings using magnetron sputtering (MS). Irrespective of the BT/HA ratios ranging from 95/5 to 80/20 wt%, nanocrystalline or highly-crystallized nature of the powders, sub-micron- or micron-sized particle dimensions, and sintering temperature, it was observed that the BT-HA reactivity cannot be prevented above 800 °C. At higher temperatures in the range of 1000–1300 °C, HA undergoes decomposition and extensively reacts with BT, leading to the formation of several secondary phases such as CaTiO3, Ba2Ca(PO4)2, BaCa6(PO4)4O, BaCa(PO3)4, and β-Ca2P2O7. As a consequence, the cytocompatibility assessed in fibroblast and osteoblast cell cultures, as well as the piezoelectric response, were significantly altered.Applying HA coatings by MS to the sintered BT ceramics successfully preserved their piezoelectric properties, while also providing an unaltered cytocompatible and osteogenic-prone surface. The HA coatings were fully crystallized at post-deposition annealing temperatures of 550 and 700 °C, achieving crystalline qualities comparable to HA powders sintered at 1100 and 1200 °C, respectively. No reactivity events between BT and HA were observed. Partial reactivity was only noticeable upon annealing at 1000 °C. Therefore, it is suggested that the HA coating of BT is effective in seamlessly coupling the piezoelectric and osteogenic properties of the two constituents without compromise.

Evaluation optimum ratio of synthetic bone graft material and platelet rich fibrin mixture in a metal 3D printed implant to enhance bone regeneration

BackgroundThis study aims to evaluate the optimal ratio of synthetic bone graft (SBG) material and platelet rich fibrin (PRF) mixed in a metal 3D-printed implant to enhance bone regeneration.MethodsSpecialized titanium hollow implants (5 mm in diameter and 6 mm in height for rabbit; 6 mm in diameter and 5 mm in height for pig) were designed and manufactured using 3D printing technology. The implants were divided into three groups and filled with different bone graft combinations, namely (1) SBG alone; (2) PRF to SBG in 1:1 ratio; (3) PRF to SBG in 2:1 ratio. These three groups were replicated tightly into each bone defect in distal femurs of rabbits (nine implants, n = 3) and femoral shafts of pigs (fifteen implants, n = 5). Animal tissue sections were obtained after euthanasia at the 8th postoperative week. The rabbit specimens were stained with analine blue, while the pig specimens were stained with Masson–Goldner’s trichrome stain to perform histologically examination. All titanium hollow implants were well anchored, except in fracture specimens (three in the rabbit and one fracture in the pig).ResultRabbit specimens under analine blue staining showed that collagen tissue increased by about 20% and 40% in the 1:1 ratio group and the 2:1 ratio group, respectively. Masson–Goldner's trichrome stain results showed that new bone growth increased by 32% in the 1:1 ratio PRF to SBG, while − 8% in the 2:1 ratio group.ConclusionThis study demonstrated that placing a 1:1 ratio combination of PRF and SBG in a stabilized titanium 3D printed implant resulted in an optimal increase in bone growth.