Bone Graft Material Research Articles

ESR measurement of carbonated hydroxyapatite for dosemeter.

We have examined a dosimetry characteristic of carbonate hydroxyapatite (CO3HAp), which is a dental bone graft material. The purpose of this work is to investigate the reproducibility and stability of radiation-induced radicals on CO3HAp samples and assess the feasibility of using these materials as dosemeters. CO3HAp samples were exposed to gamma rays with dose range from 10 to 10000Gy. The electron spin resonance (ESR) spectra for irradiated samples were measured. Variation of peak-to-peak amplitude of the ESR signal intensity as a function of absorbed dose for CO3HAp was compared with that for alanine dosemeters, suggesting that the CO3HAp sample has a good linear dose response in the range from 10to 10000Gy as well as does the alanine dosemeters.

Optimizing Bone Regeneration with Demineralized Dentin-Derived Graft Material: Impact of Demineralization Duration in a Rabbit Calvaria Model

This study evaluated the regenerative potential of demineralized dentin-derived matrix (DDM) as a bone graft material in rabbit calvaria. DDM, sourced from extracted teeth, is emerging as an alternative to traditional grafts like allografts and xenografts. We aimed to identify the most effective demineralization protocol to optimize the regenerative capacity of DDM. Four groups were compared: a control group without grafts, a non-demineralized DDM group, and two demineralized DDM groups (15 and 30 min demineralization). Histomorphometric analysis was conducted in a randomized and blinded setting at 2, 4, and 8 weeks post-graft placement. The results revealed that the 15 min demineralized DDM group showed the most significant new bone formation (42.51% ± 6.40% at 8 weeks; p < 0.05), suggesting its potential as a highly effective regenerative graft material.

Decellularized Extracellular Matrix Scaffolds: Recent Advances and Emerging Strategies in Bone Tissue Engineering.

Bone tissue engineering (BTE) is a complex biological process involving the repair of bone tissue with proper neuronal network and vasculature as well as bone surrounding soft tissue. Synthetic biomaterials used for BTE should be biocompatible, support bone tissue regeneration, and eventually be degraded in situ and replaced with the newly generated bone tissue. Recently, various forms of bone graft materials such as hydrogel, nanofiber scaffolds, and 3D printed composite scaffolds have been developed for BTE application. Decellularized extracellular matrix (DECM), a kind of natural biological material obtained from specific tissues and organs, has certain advantages over synthetic and exogenous biomaterial-derived bone grafts. Moreover, DECM can be developed from a wide range of biological sources and possesses strong molding abilities, natural 3D structures, and bioactive factors. Although DECM has shown robust osteogenic, proangiogenic, immunomodulatory, and bone defect healing potential, the rapid degradation and limited mechanical properties should be improved for bench-to-bed translation in BTE. This review summarizes the recent advances in DECM-based BTE and discusses emerging strategies of DECM-based BTE.

Vertical Alveolar Ridge Regeneration by Means of Periosteal Activation-A Proof-of-Principle Study.

To assess the possibility of vertical alveolar ridge augmentation by means of activation of the periosteum. Six adult male Beagle dogs were used for the study. All premolars and first molars were extracted, and one vertical saucer-shaped bony defect was created on each side of the mandible. After 3 months of healing, full-thickness muco-periosteal flaps were elevated, and one distraction device was placed on each side of the mandible. The distraction plate was left submerged, and the activation mechanism connected to the distraction rod was exposed intra-orally. The protocol of periosteal activation (PP: periosteal 'pumping') was initiated after a latency of 7 days. The alternation of activation and relaxation at the rate of 0.35 mm/12 h during 5 days was followed by the sole activation of 0.35 mm/12 h for 5 days (PP group). Devices were left inactivated on the contralateral control side of the mandible (C group). All animals were euthanized after 8 weeks of consolidation. Samples were analysed histologically and by means of micro-CT. New mature lamellar bone was formed over the pristine bone in all groups. More intensive signs of bone modelling and remodelling were observed in the PP group compared to the C group. Mean new bone, bone marrow, connective tissue and total volumetric densities were greater in the PP group (p < 0.001, p = 0.001, p = 0.003 and p < 0.001, respectively). No differences were observed in the relative area parameters. Total tissue volume and bone volume were higher in the PP group (p = 0.031 and p = 0.076, respectively), while the bone mineral densities were higher in the C group (p = 0.041 and p = 0.003, respectively). Trabecular number, trabecular thickness and trabecular separation values were similar between the two groups. Regeneration of vertical alveolar bone ridge defects may be enhanced by activation of the periosteum, without the application of bone grafting materials.

Maxillary sinus floor augmentation using sponge- and cotton-like graft materials in a rabbit model

ObjectivesBone graft materials commonly used for maxillary sinus floor augmentation (MSFA), including hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP), are mostly granular and have poor handleability. HAp/collagen composite material (HAp/Col) and β-tricalcium phosphate (β-TCP)/poly(L-lactide-co-glycolide) (PLGA) have shown promise but their application in MSFA as bone graft materials remains unclear. Here, we investigated the bone-forming behavior of HAp/Col and β-TCP/PLGA in an MSFA rabbit model. MethodsMale Japanese white rabbits were used. HAP/Col or β-TCP/PLGA was randomly applied to the MSFA model. The specimens were harvested at 4 weeks (W), 8W, 16W, and 24W after surgery, and the augmented regions were evaluated using micro-computed tomography and histological analyses. ResultsThe graft materials were retained up to 16W in the HAp/Col group and 24W in the β-TCP/PLGA group. The augmented volume detected in the HAp/Col group at 4W was substantially reduced at subsequent time points. However, in the β-TCP/PLGA group, the volume observed at 4W was maintained up to 24W. In the HAp/Col group, the bone mineral content (BMC) at 4W was significantly lower than that at 8W (p=0.03716), and this elevated BMC was significantly decreased at 16W (p=0.00185) and 24W (p=0.00236). In the β-TCP/PLGA group, the BMC tended to increase from 4W to 16W and then decreased. ConclusionsBoth HAp/Col and β-TCP/PLGA are useful for MSFA because of their ability to form new bone and good handleability. The appropriate graft material should be selected depending on the application needs while understanding the properties of the newly formed bone.

The Effect of Advanced Platelet-Rich Fibrin Plus (A-PRF+) on Graft Stability in Dental Implants and Alveolar Ridge Augmentation Procedures: A New Low-Speed Standardized Centrifugation Protocol

Background: Platelet-rich fibrin (PRF) is a concentrate derived from autologous blood, containing platelets, fibrin, and growth factors (GF) obtained through centrifugation. PRF can be mixed with bone replacement material to form sticky bone, which is then introduced into the desired area for stabilizing and graft-covering. Depending on the centrifugation protocol, the effectiveness of the end products can vary. This controlled clinical study examines the impact of our established PRF protocol in alveolar augmentation and dental implant placement on vertical bone loss. Materials and Methods: A total of 362 implants were performed in 170 patients at the Department of Oral and Maxillofacial Surgery at the University Hospital Innsbruck between 2018 and 2021. After accounting for lost implants, we retrospectively evaluated a radiological vertical bone loss exceeding 1 mm in the first year as the primary endpoint. Results: The use of PRF was significantly associated with vertical bone loss &gt; 1 mm (OR = 0.32, 95% CI (0.13–0.81), p = 0.016). There were no significant associations between PRF and the number of implants lost, the type of augmentation, or bone loss. Discussion: A-PRF+ sticky bone grafts, when combined with bone graft materials, show reduced resorption rates, indicating their potential to enhance graft stability in oral implantology. Our data indicate that the Medifuge MF 100 (Silfradent srl, Forlì, Italy) is effective in producing A-PRF+.

Progress in Dentin-Derived Bone Graft Materials: A New Xenogeneic Dentin-Derived Material with Retained Organic Component Allows for Broader and Easier Application.

The optimal repair of rigid mineralized tissues, such as bone, in cases of fracture, surgical resection, or prosthetic placement, is a complex process often necessitating the use of bone graft materials. Autogenous bone from the patient is generally the gold standard in terms of outcomes but also has disadvantages, which have resulted in extensive research in the field of tissue engineering to develop better and more convenient alternatives. In the dental field, several initiatives have demonstrated that the dentin material derived from extracted teeth produces excellent results in terms of repairing bone defects and supporting dental implants. Dentin is acellular and thus, in contrast to autogenous bone, cannot provide osteoblasts or other cellular elements to the grafted region, but it does contain growth and differentiation factors, and has other properties that make it an impressive material for bone repair. In this review, the beneficial properties of dentin and the ways it interacts with the host bone are described in the context of bone graft materials. Autogenous tooth material has limitations, particularly in terms of the need for tooth extraction and the limited amount available, which currently restrict its use to particular dental procedures. The development of a xenograft dentin-derived material, which retains the properties of autogenous dentin, is described. Such a material could potentially enable the use of dentin-derived material more widely, particularly in orthopedic indications where its properties may be advantageous.

The impact of root end filling material type and the application of bone graft on healing of periapical tissues after endodontic microsurgery (a clinical randomized controlled trial)

To evaluate the effect of combining different bioactive root-end filling materials with composite bone graft (xenogeneic mixed with autogenous bone fragments) on the healing process of periapical tissues after endodontic micro-surgery procedure. In this triple-blinded clinical trial, 56 patients were divided into 2 main groups (28 each) according to the root-end filling material and 2 subgroups according to the presence or absence of the composite bone graft material. Group I: MTA root-end filling (n = 28) in which there are Sub-group A: without bone graft (n = 14) and Sub-group B: with composite bone graft (n = 14). Group II: TotalFill root-end filling (n = 28) in which there are Sub-group A: without bone graft (n = 14) and Sub-group B: with composite bone graft (n = 14). Healthy patients whose ages range from 20 to 50 years with small-to-medium size radiolucency in CBCT related to single-rooted maxillary teeth were included in this study. Patients were assigned a number starting from 1 to 56 and were randomly allocated to four test groups (2 main groups and 2 sub-groups) following simple randomization procedure guidelines described by IBM SPSS V23 (IBM USA) statistical analysis software. This trial was triple-blind where the patient, the outcome assessors, and the main operator were blinded to the applied intervention. Every patient was evaluated clinically and by CBCT at two main observation periods: presurgical and 12-month post-operative. They were also examined and evaluated clinically and radiographically through periapical x-rays after one week, three, and six months. Statistical analysis was performed with IBM SPSS Statistics for Windows Version 23.0. Armonk, NY: IBM Corp. Of the 56 patients enrolled in the study, 49 patients were available for the final analysis. All groups showed no statistically significant differences with regard to healing or success rates at the 12-month follow-up mark. No adverse effects were encountered. Results showed that high success rates were achieved using MTA and TotalFill in the healing of periapical lesions after endodontic surgery. The addition of bone graft in small-to-medium size lesions did not affect the success rate of endodontic surgeries.

Bone allograft impregnated with tobramycin and vancomycin delivers antibiotics in high concentrations for prophylaxis against bacteria commonly associated with prosthetic joint infections.

Local delivery of antibiotics as prophylaxis for prosthetic joint infections (PJIs) is frequently used during total hip replacement surgery. Morselized bone allograft impregnated with vancomycin and tobramycin (TobraVanc) could provide effective prophylaxis against bacteria commonly associated with PJIs. In this study, the concentrations of antibiotics released by bone allograft impregnated with TobraVanc were determined by using an in vitro bioassay system entailing measuring inhibition zone diameters caused by antibiotic-impregnated bone chips cast in agar against standard curves. The concentrations were determined in samples of TobraVanc-impregnated bone graft taken before and after the application of the bone graft in the patients undergoing acetabular revision surgery. Antibiotic-impregnated bone grafts, sampled prior to application in the patient, delivered antibiotics in the concentration ranges of 730-9,800 mg/L for tobramycin and 1,300-11,000 mg/L for vancomycin. Samples taken after application in the patient released lower concentrations of tobramycin (490-1,900 mg/L; P < 0.01) and vancomycin (3,000-5,100 mg/L; P < 0.05); however, these concentrations remained well above the tobramycin minimum inhibitory concentrations (MICs) for investigated, highly tobramycin-resistant Staphylococcus epidermidis strains (MICs > 256 mg/L). At the tested concentrations, bone graft material mixed with TobraVanc delivered antibiotics in potent concentrations above the MICs for bacteria causing PJIs. Clinical trials are needed to evaluate the efficacy and risk of TobraVanc-impregnated bone graft as a prophylactic agent for patients undergoing hip replacement surgery.IMPORTANCEAntibiotic prophylaxis is the cornerstone of successful joint replacement surgery, reducing the risk for the dreaded complication of prosthetic joint infection (PJI) to roughly 0.5%-2% in standard total hip replacement (THR). In addition to systemic antibiotics, antibiotics added locally have the potential to reduce the PJI risk even further, because of the high concentrations that can be achieved in the joint with limited risk for systemic toxicity. The results in the current study show that bone chips impregnated with a combination of tobramycin and vancomycin (TobraVanc) release antibiotics in concentrations that are potent against common bacteria causing PJIs. Especially in high-risk patients, our results support the prophylactic use of TobraVanc in hip replacement surgery requiring the use of a bone graft. A clinical study testing the efficacy of TobraVanc-impregnated bone graft in reducing the incidence of PJI in hip replacement surgery is currently ongoing (EudraCT: 2021-001708-14).

Physicochemical Characterization of Nanohydroxyapatite Powder in Simulated Body Fluid Immersion: A Pilot Study

Nanohydroxyapatite (n-HA) has been widely used as a bone graft material. In contact with biological fluids, n-HA should be reactive, resorbable, form an bone-like apatite layer on their surfaces, and enhance osseointegration. The release of Ca, P, and O in SBF predicted the formation of bone-like apatite layer. Therefore, this study aims to investigate the physicochemical properties of nano-HA powder during the SBF immersion in vitro. The n-HA powder was immersed in SBF for 24, 48 hours, 7, 14, and 28 days. The swelling ratio, pH, FTIR, and SEM-EDX were analyzed pre- and post-SBF immersion. The n-HA powder showed excellent hydrophilicity and a stable pH, even though there was a pH decrease in 28 days. The carbonate and phosphate functional groups were found through FTIR, in line with the ion composition changes and increase of the Ca/P ratio shown on EDX. Both mean weight percentages (%) of Ca and P increased during 14 days of SBF immersion (16.15 to 27.27; and 8.57 to 11.68, respectively). The other functional groups on the n-HA are PO3 −, CO2 −, O-H, C=H, and COO. In conclusion, the n-HA powder presents good physicochemical properties that indicate the formation of an apatite bonelike layer and is promising as a bone graft material.

Autogenous platelet concentrates for treatment of intrabony defects-A systematic review with meta-analysis.

To provide an overview of the use of autogenous platelet concentrates (APCs) in periodontal regeneration and to conduct a systematic review (SR) of the treatment outcomes of periodontal intrabony defects by using platelet-rich fibrin (PRF) compared with other commonly utilized modalities. The eligibility criteria comprised randomized controlled trials (RCTs) comparing the clinical outcomes of PRF with that of other modalities. Studies were classified into 21 categories and into five different groups as follows: Group I (1) open flap debridement (OFD) alone versus OFD/PRF, (2) OFD versus Titanium-PRF (T-PRF) Group II, (3) Comparative PRF protocols (PRF vs. T-PRF), Group III (Comparative Studies to PRF): (4) OFD/PRP versus OFD/PRF, (5) OFD/bone graft(BG)/PRGF versus OFD/BG/PRF, (6) OFD/EMD versus OFD/PRF, (7) OFD/BG/EMD versus OFD/BG/PRF, (8) OFD/collagen membrane (CM) versus OFD/PRF, (9) OFD/BG/BM versus OFD/BG/PRF, (10) OFD/BG versus OFD/PRF, Group IV (Addition of PRF to treatment groups) (11) OFD/BG versus OFD/BG/PRF, (12) OFD/GTR versus OFD/GTR + PRF (13) OFD/EMD versus OFD/EMD/PRF (14) OFD/BG/BM versus OFD/BG/BM/PRF, Group V (Addition of Biomaterial/Biomolecule to PRF): OFD/PRF versus … (15) OFD/PRF/BG, (16) OFD/PRF/antibiotic, (17) OFD/PRF/Metformin, (18) OFD/PRF/Bisphosphonates, (19) OFD/PRF/Statins, (20) OFD/BG/PRF versus OFD/BG/PRF/Statins, and (21) OFD/PRF/low-level laser therapy (LLLT). Weighted means and forest plots were calculated for probing pocket depth (PPD), clinical attachment level (CAL), and radiographic bone fill (RBF). From 596 records identified, 55 RCTs were included. Group I: The use of OFD/PRF statistically significantly reduced PPD and improved CAL and RBF when compared to OFD. Group II: A significant difference between various PRF protocols was only observed for PPD. Group III: No significant advantage was found when comparing OFD/PRF to the following groups: OFD/PRP, OFD/EMD, OFD/BM, or OFD/BG. Group IV: The addition of PRF to OFD/BG led to significant improvements in PPD, CAL and RBF compared with OFD/BG alone. Group V: The addition of either a BG as well as three of the following biomolecules (metformin, bisphosphonates, and statins) to OFD/PRF led to statistically significant improvements in PPD, CAL, and/or RBF when compared to OFD/PRF alone. The use of PRF significantly improved clinical outcomes in intrabony defects when compared to OFD alone. Similar results were observed when OFD/PRF was compared with OFD/BG, OFD/EMD, OFD/PRP, and OFD/BM. The addition of PRF to a bone grafting material as well as the addition of various small biomolecules to PRF may offer additional clinical advantages, thus warranting further investigations. Future research investigating various protocols of PRF, longer-term outcomes, as well as PRF at the human histological level remains needed.

In Vivo Evaluation of Demineralized Bone Matrix with Cancellous Bone Putty Formed Using Hydroxyethyl Cellulose as an Allograft Material in a Canine Tibial Defect Model.

Demineralized bone matrix (DBM) is a widely used allograft material for bone repair, but its handling properties and retention at defect sites can be challenging. Hydroxyethyl cellulose (HEC) has shown promise as a biocompatible carrier for bone graft materials. This study aimed to evaluate the efficacy of DBM combined with cancellous bone putty formed using HEC as an allograft material for bone regeneration in a canine tibial defect model. Experiments were conducted using dogs with proximal tibial defects. Four groups were compared: empty (control group), DBM + HEC (DH), DBM + cancellous bone + HEC (DCH), and DBM + cancellous bone + calcium phosphate + HEC (DCCH). Radiographic, micro-computed tomography (CT), and histomorphometric evaluations were performed 4 and 8 weeks postoperatively to assess bone regeneration. The Empty group consistently exhibited the lowest levels of bone regeneration throughout the study period, indicating that DBM and cancellous bone with HEC significantly enhanced bone regeneration. At week 4, the DCCH group showed the fastest bone regeneration on radiography and micro-computed tomography. By week 8, the DCH group showed the highest area ratio of new bone among all experimental areas, followed by the DH and DCCH groups. This study demonstrated that HEC significantly enhances the handling, mechanical properties, and osteogenic potential of DBM and cancellous bone grafts, making it a promising carrier for clinical applications in canine allograft models. When mixed with allograft cancellous bone, which has high porosity and mechanical strength, it becomes a promising material offering a more effective and reliable option for bone repair and regeneration.

Mechanistic Insights of Amino Acid Binding to Hydroxyapatite: Molecular Dynamics Charts Future Directions in Biomaterial Design.

Extensive efforts have been made to improve the understanding of hard tissue regeneration, essential for advancing medical applications like bone graft materials. However, the mechanisms of bone biomineralization, particularly the regulation of hydroxyapatite growth by proteins/peptides, remain debated. Small biomolecules such as amino acids are ideal for studying these mechanisms due to their simplicity and relevance as protein/peptide building blocks. This study investigates the binding affinity of four amino acids including glycine (Gly), proline (Pro), lysine (Lys), and aspartic acid (Asp) to the hydroxyapatite (HAP) (100) surface through molecular dynamics simulations. Our findings reveal that aspartic acid exhibits the most energetically favorable binding affinity, attributed to its additional carboxylate group (-COO-), which facilitates stronger interactions with Ca2+ ions on the HAP surface compared to other amino acids with single carboxylate groups. This highlights the critical role of specific functional groups in modulating binding strength, emphasizing that the presence of multiple binding sites in amino acids enhances binding stability. Interestingly, the study also uncovers the significance of water-mediated interactions, as the compact water layer above the HAP surface acts as a barrier, complicating direct binding and underscoring the need to consider solvation effects in simulations. Glycine, due to its small size, demonstrates a unique ability to penetrate this tightly bound water monolayer, suggesting that molecular size influences binding dynamics. These simulations offer detailed insights into the atomic-level interactions, providing a deeper understanding of binding affinity and stability. These insights are pertinent for designing peptides or proteins with enhanced interactions with biomaterials, particularly in mimicking natural bone-binding processes.

Navigating the combinations of platelet-rich fibrin with biomaterials used in maxillofacial surgery.

Platelet-rich fibrin (PRF) is a protein matrix with growth factors and immune cells extracted from venous blood via centrifugation. Previous studies proved it a beneficial biomaterial for bone and soft tissue regeneration in dental surgeries. Researchers have combined PRF with a wide range of biomaterials for composite preparation as it is biocompatible and easily acquirable. The results of the studies are difficult to compare due to varied research methods and the fact that researchers focus more on the PRF preparation protocol and less on the interaction of PRF with the chosen material. Here, the literature from 2013 to 2024 is reviewed to help surgeons and researchers navigate the field of commonly used biomaterials in maxillofacial surgeries (calcium phosphate bone grafts, polymers, metal nanoparticles, and novel composites) and their combinations with PRF. The aim is to help the readers select a composite that suits their planned research or medical case. Overall, PRF combined with bone graft materials shows potential for enhancing bone regeneration both in vivo and in vitro. Still, results vary across studies, necessitating standardized protocols and extensive clinical trials. Overviewed methods showed that the biological and mechanical properties of the PRF and material composites can be altered depending on the PRF preparation and incorporation process.

Autogenous Tooth Graft Biomaterial in Guided Bone Regeneration: A Comprehensive Review

Objective: This review evaluated the use of autogenous tooth as a bone graft material in guided bone regeneration (GBR). Moreover, it compared the results of GBR using autogenous demineralized dentin, partially demineralized dentin, and mineralized dentin with or without membrane to verify its clinical advantage, effectiveness, and safety. Methods: A search was conducted in PubMed/MEDLINE, Lilacs, Embase, Cochrane, and Scopus databases. Specific criteria were established for the inclusion and exclusion of studies, including types of studies considered, target population (clinical studies: humans), evaluated intervention (studies assessing and comparing autologous demineralized dentin, partially demineralized dentin, and mineralized dentin in GBR with or without resorbable membrane), and language and publication period of articles (English and published in the last 11 years). A detailed assessment of the methodological quality of the selected studies was conducted using the JBI critical appraisal tool. Results: Based on the analysis conducted, out of 174 potentially relevant articles obtained, only 19 publications met the inclusion criteria, with three papers showing medium quality/moderate risk of bias and the rest with high quality/low risk of bias. Comparison between groups revealed stability of the newly formed bone, low marginal bone loss, clinically acceptable primary and secondary implant stability quotient (ISQ) values, and high implant survival rates after using autogenous tooth biomaterial. Conclusions: The results of this review on the use of autogenous teeth as a bone graft material in guided bone regeneration indicated that the technique has the potential to be an effective and safe treatment option. Analysis of selected studies showed favorable evidence for the use of autogenous teeth in bone regeneration, suggesting clinical benefits, most for socket preservation. These results are relevant for guiding clinical practice and assisting dental professionals in having options for biomaterials for bone regeneration.

Preparation of decellularized bone graft material with supercritical carbon dioxide extraction technique.

To evaluate the immunogenicity and osteogenic ability of animal-derived bone graft material decellularized with supercritical carbon dioxide. Porcine femurs were randomly divided into two groups after preliminary treatment, and decellularized with conventional method (conventional control group) or supercritical carbon dioxide (experimental group). Clearance rate of galactose-α-1, 3-galactose (α-Gal) and residual DNA of the two groups were analyzed to assess the immunogenicity of the xenogenic materials. Clearance rate of α-Gal was determined by enzyme-linked immunosorbent assay and residual DNA was detected by fluorescence method. Nine SPF-grade male athymic nude mice of 6 weeks old were randomly divided into experimental group, conventional control group and positive control group. Samples were implanted over biceps femoris muscle of athymic nude mice, the explants were collected 4 weeks post implantation, hematoxylin and eosin (HE) staining and immunohistochemistry were applied to determine the osteogenic ability and bone tissue-associated protein expressions of the implants. The clearance rates of α-Gal antigen in the experimental group and the conventional control group were (99.09±0.26)% and (30.18±2.02)%, respectively (t=58.67, P<0.01). The residual DNA of the experimental group, the conventional control group and the positive control group were (13.49±0.07) ng/mg, (15.20±0.21) ng/mg and (14.70±0.17) ng/mg, the residual DNA in the experimental group was significantly lower than that in the conventional control group (t=－13.41, P<0.01) and the positive control group (t=－11.30, P<0.01). HE staining showed that multiple bone formation centers with active osteogenesis and rich bone marrow were observed in experimental group 4 weeks after implantation, only a small number of bone formation centers were observed in the conventional control group and the positive control group, with no obvious osteoblasts present. Immunohistochemistry results indicated that the expressions of alkaline phosphatase, Runt-related transcription factor 2, typeⅠcollagen and osteocalcin in the experimental group showed an increasing trend compared with those in the conventional control group and the positive control group. Compared with clinically used demineralized bone matrix and bone graft material decellularized with conventional method, bone graft material decellularized with supercritical carbon dioxide exhibits lower immunogenicity and better osteogenic ability.

Adsorption and Release Pattern of Recombinant Human Bone Morphogenic Proatin 2 onto Different Bone Grafts and its Consequent Osteoblasts` Activation and Neutrophils` Priming

ObjectivesControlled long-term delivery of recombinant human bone morphogenic proatin 2 (rhBMP2) eluted in a collagen scaffolds suffer from only a high initial burst release. The purpose of the current study was to investigate the long-term delivery of rhBMP2 when mixed with different bone grafts and its impact on osteoblastic activity and neutrophil priming. MethodsrhBMP2 was separately mixed with xenograft, allograft, or alloplast and incubated for 30 days. Levels of BMP2 adsorption and their release were measured using immunofluorescence and ELISA respectively. The supernatants from the grafts were then incubated with either osteoblast (Saos-2 cells) or neutrophils (differentiated from HL60) for alkaline phosphatase and oxidative stress measurements respectively. Gene expression of osteoblast functionality and neutrophil priming were measured with qRT-PCR. ResultsrhBMP2 was adsorbed onto all tested grafts, with a superior effect of alloplast. The release of the rhBMP2 from all grafts was similar and sustained for 30 days with the lowest levels in the alloplast group. Activation of osteoblast was robust in the allograft and xenograft groups, concomitant with elevated osteocalcin expression. Neutrophil priming was greatest in the xenograft group, together with elevated expression of interleukin 1β. ConclusionrhBMP2 with bone graft material constitutes its sustained release over time. This, in turn, robust osteoblast and neutrophil activity.

Unleashing innovation: 3D-printed biomaterials in bone tissue engineering for repairing femur and tibial defects in animal models - a systematic review and meta-analysis.

3D-printed scaffolds have emerged as an alternative for addressing the current limitations encountered in bone reconstruction. This study aimed to systematically review the feasibility of using 3D bio-printed scaffolds as a material for bone grafting in animal models, focusing on femoral and tibial defects. The primary objective of this study was to evaluate the efficacy, safety, and overall impact of these scaffolds on bone regeneration. Electronic databases were searched using specific search terms from January 2013 to October 2023, and 37 relevant studies were finally included and reviewed. We documented the type of scaffold generated using the 3D printed techniques, detailing its characterization and rheological properties including porosity, compressive strength, shrinkage, elastic modulus, and other relevant factors. Before incorporating them into the meta-analysis, an additional inclusion criterion was applied where the regenerated bone area (BA), bone volume (BV), bone volume per total volume (BV/TV), trabecular thickness (Tb. Th.), trabecular number (Tb. N.), and trabecular separation (Tb. S.) were collected and analyzed statistically. 3D bio-printed ceramic-based composite scaffolds exhibited the highest capacity for bone tissue regeneration (BTR) regarding BV/TV of femoral and tibial defects of animal models. The ideal structure of the printed scaffolds displayed optimal results with a total porosity >50% with a pore size ranging between 300- and 400µM. Moreover, integrating additional features and engineered macro-channels within these scaffolds notably enhanced BTR capacity, especially observed at extended time points. In conclusion, 3D-printed composite scaffolds have shown promise as an alternative for addressing bone defects.

Polycaprolactone Hybrid Scaffold Loaded With N,O-Carboxymethyl Chitosan/Aldehyde Hyaluronic Acid/Hydroxyapatite Hydrogel for Bone Regeneration.

Hydrogels have emerged as potential materials for bone grafting, thanks to their biocompatibility, biodegradation, and flexibility in filling irregular bone defects. In this study, we fabricated a novel NAH hydrogel system, composed of N,O-carboxymethyl chitosan (NOCC), aldehyde hyaluronic acid (AHA), and hydroxyapatite (HAp). To improve the mechanical strength of the fabricated hydrogel, a porous polycaprolactone (PCL) matrix was synthesized and used as a three-dimensional (3D) support template for NAH hydrogel loading, forming a novel PCL/NAH hybrid scaffold. A mixture of monosodium glutamate (M) and sucrose (S) at varied weight ratios (5M:5S, 7M:3S, and 9M:1S) was used for the fabrication of 3D PCL matrices. The morphology, interconnectivity, and water resistance of the porous PCL scaffolds were investigated for optimal hydrogel loading efficiency. The results demonstrated that PCL scaffolds with porogen ratios of 7M:3S and 9M:1S possessed better interconnectivity than 5M:5S ratio. The compressive strength of the PCL/NAH hybrid scaffolds with 9M:1S (561.6 ± 6.1 kPa) and 7M:3S (623.8 ± 6.8 kPa) ratios are similar to cancellous bone and all hybrid scaffolds were biocompatible. Rabbit models with tibial defects were implanted with the PCL/NAH scaffolds to assess the wound healing capability. The results suggest that the PCL/NAH hybrid scaffolds, specifically those with porogen ratio of 7M:3S, exhibit promising bone healing effects.

Clinical practice guideline for autologous bone grafting in China (2024 edition)

Autogenous bone has always been the gold-standard bone graft material. As such, it is the primary choice for bony grafts. Autogenous bone grafting has been performed for hundreds of years, and more than 2 million cases of autogenous bone transplantation are performed each year worldwide. It has become the most commonly used surgical method in orthopedics. Numerous studies have suggested methods to select the appropriate donor area, standardize the surgical procedure, and reduce donor site complications, but clinical standards and guidelines remain to be established. To better guide the clinical practice of physicians in China, the Trauma Orthopedic Branch of the Chinese Orthopedic Association, the External Fixation and Limb Reconstruction Branch of the Chinese Orthopedic Association, and the Microsurgery Branch of the Beijing Orthopedic Association developed the "Clinical practice guideline for autogenous bone grafting in China (2024 edition)" based on current medical evidence. This guideline systematically evaluates recent domestically and internationally published literature and medical research evidence in the field of autologous bone grafting in the Chinese population. The guideline was produced with the aim of standardizing the indications and techniques for autogenous bone transplantation, as well as preventing complications at the harvesting site of autologous bone, in the Chinese population.