Search Results (2,231)

Introduction: Segmental tibial defects pose significant challenges in orthopedic surgery due to their complexity and high complication rates. This systematic review aimed to evaluate both the effectiveness and outcomes of distraction osteogenesis (D.O.) and the Masquelet technique in treating post-traumatic segmental tibial defects. Materials and Methods: A literature search was performed on PubMed, Scopus, and Cochrane. Relevant retrospective and prospective observational studies with a minimum of 12 months follow-up were included. The primary outcome was bone union rate; the secondary outcomes were the type and rate of complications and the clinical and radiological outcomes. Results: Twenty-seven studies met the inclusion criteria, 18 studies reported data on D.O. and 9 on the Masquelet technique. D.O. demonstrated an overall union rate of 79.4% across 422 patients, and the Masquelet technique demonstrated an overall bone union rate of 85% across 113 patients. For D.O., on average, there was one complication per patient, and with the Masquelet technique, there were 0.5 complications per patient. Conclusions: D.O. and the Masquelet technique are the main treatment options for post-traumatic segmental tibial defects. Although union rates are similar, the Masquelet technique showed fewer complications. Treatment choice should consider patient-specific factors and more comparative studies are needed. Full article

It was assumed that only autogenous bone had appropriate osteoconductive and osteoindutive properties for bone regeneration, but this assumption has been challenged. Many studies have shown that synthetic biomaterials must be considered as the best choice for guided bone regeneration. The objective of this work is to compare the performances of nanohydroxyapatite/β-tricalcium phosphate (n-HA/β-TCP) composite and autogenous bone grafting in bone regeneration applications. The composite was characterized by scanning electron microscopy (SEM) and used as an allograft in bone defects formed in adult Wistar rats. The bone defects in the dorsal cranium were grafted with autogenous bone on one side and the n-HA/β-TCP composite on the other. Histomorphometry evaluation via different staining methods (Goldner trichrome, PAS, and Sirius red) and TRAP histochemistry were performed. Immunohistomorphometries of OPN, Cathepsin K, TRAP, acid phosphatase, VEGF, NFκ-β, MMP-2, MMP-9, and TGF-β were carried out. The RT-PCR method was also applied to to RANK-L, Osteocalcine, Alcaline Phosphatase, Osterix, and Runx2. The results showed that for all morphometric evaluations with the different staining methods, histochemistry, and immunohistochemistry, VEGF and NFκ-β were higher in the n-HA/β-TCP composite group than in the autogenous bone graft group. The RT-PCR markers were higher in the autogenous bone group than in the n-HA/β-TCP composite group. The n-HA/β-TCP composite exhibited enhanced cell–matrix interactions in bone remodeling, higher adhesion, proliferation, and differentiation, and increased vascularization. These results suggest that the n-HA/β-TCP composite induces faster bone formation than autogenous bone grafting. Full article

Background. The impact of tongue protrusion forces on the formation of malocclusions is well documented in academic literature. In the case of bone dehiscence of the buccal wall in front of the lower frontal teeth, this process may be even more pronounced. Augmentation with 3D customized allogenic bone blocks (CABB) has been proposed as a potential solution for treating such defects. The objective was to assess the impact of bone block adjustment accuracy on the resistance of teeth to protrusion forces at various stages of alveolar bone loss. Methods: A finite element analysis (FEM) was conducted to ascertain whether augmentation with a CABB will result in increased resilience to tongue protrusion forces. Three-dimensional models of the mandible with dehiscenses were created, based on the dehiscences classification and modification proposed in the journal by the authors of regenerative method. The models feature a CABB positioned at three different distances: 0.1 mm, 0.4 mm, and 1.0 mm. The material parameters were as follows: bone (homogenous, isotropic, E = 2 GPa), teeth (E = 20 GPa), periodontal ligament (E = 0.44 MPa), and membrane between bones (E = 3.4 MPa). A tongue protrusion force within the range of 0–5 N was applied to each individual frontal tooth. Results: The use of an CABB has been shown to positively impact the stability of the teeth. The closer the bone block was placed to the alveolar bone, the more stable was the result. The best results were obtained with a ¼ dehiscence and 0.1 mm distance. Conclusions: The protrusive forces produced by the tongue might not be the biggest one, but in a presence of the bone loss they might have serious results. Even shortly after the surgery, CABB has a positive impact on the incisor resilience. Full article

Hyaluronic acid was proposed to support soft tissue recession surgery and guided tissue regeneration. The molecular mechanisms through which hyaluronic acid modulates the response of connective tissue cells remain elusive. To elucidate the impact of hyaluronic acid on the connective tissue cells, we used bulk RNA sequencing to determine the changes in the genetic signature of gingival fibroblasts exposed to 1.6% cross-linked hyaluronic acid and 0.2% natural hyaluronic acid. Transcriptome-wide changes were modest. Even when implementing a minimum of 1.5 log2 fold-change and a significance threshold of 1.0 −log10, only a dozenth of genes were differentially expressed. Upregulated genes were PLK3, SLC16A6, IL6, HBEGF, DGKE, DUSP4, PTGS2, FOXC2, ATAD2B, NFATC2, and downregulated genes were MMP24 and PLXNA2. RT-PCR analysis supported the impact of hyaluronic acid on increasing the expression of a selected gene panel. The findings from bulk RNA sequencing suggest that gingival fibroblasts experience weak changes in their transcriptome when exposed to hyaluronic acid. Full article

Background and Objectives: Current craniofacial reconstruction surgical methods have limitations because they involve facial deformation. The craniofacial region includes many areas where the mucosa, exposed to air, is closely adjacent to bone, with the maxilla being a prominent example of this structure. Therefore, this study explored whether human neural-crest-derived stem cells (hNTSCs) aid bone and airway mucosal regeneration during craniofacial reconstruction using a rabbit model. Materials and Methods: hNTSCs were induced to differentiate into either mucosal epithelial or osteogenic cells in vitro. hNTSCs were seeded into polycaprolactone scaffold (three-dimensionally printed) that were implanted into rabbits with maxillary defects. Four weeks later, tissue regeneration was analyzed via histological evaluation and immunofluorescence staining. Results: In vitro, hNTSCs differentiated into both mucosal epithelial and osteogenic cells. hNTSC differentiation into respiratory epithelial cells was confirmed by Alcian Blue staining, cilia in SEM, and increased expression levels of FOXJ1 and E-cadherin through quantitative RT-PCR. hNTSC differentiation into bone was confirmed by Alizarin Red staining, increased mRNA expression levels of BMP2 (6.1-fold) and RUNX2 (2.3-fold) in the hNTSC group compared to the control. Four weeks post-transplantation, the rabbit maxilla was harvested, and H&E, SEM, and immunohistofluorescence staining were performed. H&E staining and SEM showed that new tissue and cilia around the maxillary defect were more prominent in the hNTSC group. Also, the hNTSCs group showed positive immunohistofluorescence staining for acetylated α-tubulin and cytokerin-5 compared to the control group. Conclusions: hNTSCs combined with PCL scaffold enhanced the regeneration of mucosal tissue and bone in vitro and promoted mucosal tissue regeneration in the in vivo rabbit model. Full article

Background: The use of ex vivo assays associated with biomaterials may allow the short-term visualization of a specific cell type response inserted in a local microenvironment. Blood is the first component to come into contact with biomaterials, providing blood clot formation, being substantial in new tissue formation. Thus, this research investigated the physiological blood clot (PhC) patterns formed in 3D scaffolds (SCAs), based on chitosan and 20% beta-tricalcium phosphate and its effect on osteogenesis. Initially, SCA were inserted for 16 h in rats calvaria defects, and, after that, osteoblasts cells (OSB; UMR-106 lineage) were seeded on the substrate formed. The groups tested were SCA + OSB and SCA + PhC + OSB. Cell viability was checked by MTT and mineralized matrix formation in OSB using alizarin red (ARS). The alkaline phosphatase (ALP) and bone sialoprotein (BSP) expression in OSB was investigated by indirect immunofluorescence (IF). The OSB and PhC morphology was verified by scanning electron microscopy (SEM). Results: The SCA + PhC + OSB group showed greater cell viability (p = 0.0169). After 10 days, there was more mineralized matrix deposition (p = 0.0365) and high ALP immunostaining (p = 0.0021) in the SCA + OSB group. In contrast, BSP was more expressed in OSB seeded on SCA with PhC (p = 0.0033). Conclusions: These findings show the feasibility of using PhC in ex vivo assays. Additionally, its inclusion in the experiments resulted in a change in OSB behavior when compared to in vitro assays. This “closer to nature” environment can completely change the scenario of a study. Full article

Mandibular bone defect reconstruction remains a significant challenge for surgeons worldwide. Among multiple biodegradable biopolymers, allogeneic bone scaffolds derived from human sources have been used as an alternative to autologous bone grafts, providing optimal conditions for cell recruitment, adhesion, and proliferation and demonstrating significant osteogenic properties. This study aims to investigate the bone microstructure of the human scapula as a source for allogeneic bone scaffold fabrication for mandibular tissue engineering purposes. We created color-coded anatomical maps of the scapula and the mandible, reflecting the best anatomical and geometrical match. In this pilot study, we hypothesized a microstructural similarity of these bone structures and evaluated the human scapula’s bone tissue engineering potential for mandibular bone tissue engineering by focusing on the microstructural characteristics. Lyophilized human scapular and mandibular bioimplants were manufactured and sterilized. Experimental bone samples from the scapula’s acromion, coracoid, and lateral border from the mandibular condyle, mandibular angle, and mental protuberance were harvested and analyzed using micro-CT and quantitative morphometric analysis. This pilot study demonstrates significant microstructural qualitative and quantitative intra-group differences in the scapular and mandibular experimental bone samples harvested from the various anatomical regions. The revealed microstructural similarity of the human scapular and mandibular bone samples, to a certain extent, supports the stated hypothesis and, thus, allows us to suggest the human scapula as an alternative off-the-shelf allogeneic scaffold for mandibular reconstruction and bone tissue engineering applications. Full article

Background: The reparative regeneration of jawbone defects poses a significant challenge within the field of dentistry. Despite being the gold standard, autogenous bone materials are not without drawbacks, including a heightened risk of postoperative infections. Consequently, the development of innovative materials that can surpass the osteogenic capabilities of autologous bone has emerged as a pivotal area of research. Methods: Mesenchymal stem cells (MSCs), known for their multilineage differentiation potential, were isolated from human umbilical cords and transfected with miR-181a. The osteogenic differentiation of miR-181a/MSC was investigated. Then, physicochemical properties of miR-181a/MSC-loaded nano-hydroxyapatite (nHAC) scaffolds were characterized, and their efficacy and underlying mechanism in rat calvarial defect repair were explored. Results: miR-181a overexpression in MSCs significantly promoted osteogenic differentiation, as evidenced by increased alkaline phosphatase activity and expression of osteogenic markers. The miR-181a/MSC-loaded nHAC scaffolds exhibited favorable bioactivity and accelerated bone tissue repair and collagen secretion in vivo. Mechanistic studies reveal that miR-181a directly targeted the TP53/SLC7A11 pathway, inhibiting ferroptosis and enhancing the osteogenic capacity of MSCs. Conclusions: The study demonstrates that miR-181a/MSC-loaded nHAC scaffolds significantly enhance the repair of bone defects by promoting osteogenic differentiation and inhibiting ferroptosis. These findings provide novel insights into the molecular mechanisms regulating MSC osteogenesis and offer a promising therapeutic strategy for bone defect repair. Full article

This review explores the advancements in additive manufacturing (AM) of biodegradable iron (Fe) and zinc (Zn) alloys, focusing on their potential for medical implants, particularly in vascular and bone applications. Fe alloys are noted for their superior mechanical properties and biocompatibility but exhibit a slow corrosion rate, limiting their biodegradability. Strategies such as alloying with manganese (Mn) and optimizing microstructure via laser powder bed fusion (LPBF) have been employed to increase Fe’s corrosion rate and mechanical performance. Zn alloys, characterized by moderate biodegradation rates and biocompatible corrosion products, address the limitations of Fe, though their mechanical properties require improvement through alloying and microstructural refinement. LPBF has enabled the fabrication of dense and porous structures for both materials, with energy density optimization playing a critical role in achieving defect-free parts. Fe alloys exhibit higher strength and hardness, while Zn alloys offer better corrosion control and biocompatibility. In vitro and in vivo studies demonstrate promising outcomes for both materials, with Fe alloys excelling in load-bearing applications and Zn alloys in controlled degradation and vascular applications. Despite these advancements, challenges such as localized corrosion, cytotoxicity, and long-term performance require further investigation to fully harness the potential of AM-fabricated Fe and Zn biodegradable implants. Full article

This article presents an evaluation of the accelerated aging impact on the structural properties of biodegradable PLA/HAp implants produced using 3D printing technology for use in traumatic bone defect repairs in individual patients. The designed biodegradable implants were sterilized with a radiation dose of 25 ± 0.99% kGy, then exposed to an accelerated aging process. Selected physicomechanical and chemical properties of biodegradable implants were evaluated with FT-IR spectra analyses and DSC. The accelerated aging process, carried out according to the ASTM F 1980:2002 “Standard Guide for Accelerated Aging of Sterile Barrier Systems and Medical Devices”, simulates three years of implant usage. It confirmed the stability of structural, physical and mechanical properties and proved the effectiveness and safety of the implants’ application. The present study was conducted to determine the shelf-life of newly developed biodegradable implants proposed for the treatment of children and adolescents where bone growth still occurs by using accelerated aging methodologies, allowing the assessment of changes in performance that do not result in a negative impact on the safety of the medical device. Full article

Background/Objectives: Traditional autologous bone grafts as a treatment for bone defects have drawbacks like donor-site morbidity and limited supply. PerOssal^®, a ceramic bone substitute, may overcome those drawbacks and could offer additional benefits like prolonged, local antibiotic release. This study investigates the clinical and radiological outcomes, including patient-reported outcomes, of using PerOssal^® in nonunions (NU) and high-grade chronic osteomyelitis (COM). Methods: A single-center, retrospective study, investigating patients treated with PerOssal^® between January 2020 and December 2023. Collected data include patient characteristics as well as various surgical and outcome parameters including the Lower Extremity Functional Scale (LEFS). Results: A total of 82 patients were analyzed. Reinfection occurred in 19.5% of cases. Osseous integration of PerOssal^® was achieved in 89% of cases, higher in cavitary defects (91.5%) than segmental defects (72.7%). The revision rate was 32.9%, mainly due to wound healing disorders and reinfections. Mean LEFS score was 53.4 which was heavily influenced by sex (male: 50.7 vs. female: 63.4), revision surgery (no: 55.7 vs. yes: 49.1), reinfection (no: 56.6 vs. yes: 39.4), and osseous integration of PerOssal^® (yes: 55.8 vs. no: 38.4). Conclusions: PerOssal^® demonstrates promising outcomes in treating NUs and high-grade COM, especially in cavitary defects, with high osseous integration rates and acceptable functional results. However, reinfection remains a concern, particularly with difficult-to-treat pathogens and extensive surgical histories. Early, comprehensive surgical intervention and tailored antibiotic strategies are essential. Patient selection, defect characteristics, and comorbidities significantly influence success. Further research is needed to optimize treatment protocols. Full article

With the development of 3D bioprinting and the creation of innovative biocompatible materials, several new approaches have brought advantages to patients and surgical teams. Increasingly more bone defects are now treated using 3D-bioprinted prostheses and implementing new solutions relies on the ability of engineers and medical teams to identify methods of anchoring 3D-printed prostheses and to reveal the potential influence of bioactive materials on surrounding tissues. In this paper, we described why limb salvage surgery based on 3D bioprinting is a reliable and effective alternative to amputations, and why this approach is considered the new standard in modern medicine. The preliminary results of 3D bioprinting in one of the most challenging fields in surgery are promising for the future of machine-based medicine, but also for the possibility of replacing various parts from the human body with bioactive-based constructs. In addition, besides the materials and constructs that are already tested and applied in the human body, we also reviewed bioactive materials undergoing in vitro or in vivo testing with great potential for human applications in the near future. Also, we explored the recent advancements in clinically available 3D-bioprinted constructs and their relevance in this field. Full article

Biogenic hydroxyapatite is known for its osteoinductive potential due to its similarity to human bone and biocompatibility, but insufficient vascularization compared to autogenous bone during early implantation limits bone integration and osteogenesis. Fluorine has been shown to improve hydroxyapatite’s mechanical properties and the coupling of osteogenic and angiogenic cells. In this study, fluorine-modified biogenic hydroxyapatite (FPHA) with varying fluorine concentrations was prepared and tested for its ability to promote vascularized osteogenesis. FPHA prepared in this study retained the natural porous structure of biological cancellous bone and released F⁻ ions when immersed in cell culture medium. The extraction solutions of FPHA0.25 and FPHA0.50 promoted the formation of capillary-like tubes by human umbilical vein endothelial cells (HUVECs), with FPHA0.25 significantly upregulating vegf mRNA and VEGF protein levels in co-cultured human bone marrow mesenchymal stem cells (HBMSCs). Additionally, FPHA0.25 and FPHA0.50 upregulated pdgf-bb mRNA and PDGF-BB protein levels in HUVECs. In vivo experiments using a rabbit cranial defect model demonstrated that FPHA0.25 promoted early bone formation and angiogenesis in the defect area, enhanced VEGF secretion, and increased PDGFR-β expression in endothelial and mesenchymal cells. These findings suggest that fluorine-modified biogenic hydroxyapatite with an optimal fluorine concentration (FPHA0.25) may offer a promising strategy to enhance the body’s innate bone-healing potential by accelerating vascularization. Full article

This research investigates how the inclusion of bone glue affects the performance of traditional painted furniture ground layers, particularly under dry–wet cycling conditions. The ground layers, applied to wood substrates in seven different ratios of bone glue to gypsum powder (10%, 20%, 30%, 40%, 50%, and 60%), were tested for mass changes, dimensional stability, adhesion, and surface roughness. The results showed that higher bone glue content (especially 50% and 60%) led to improved stability, reduced mass fluctuations, and better dimensional stability. The 50% bone glue sample exhibited the best overall stability with minimal weight change (<1.6%) and reduced shrinkage. Adhesion strength increased with bone glue content, reaching 3.48 MPa at 60% bone glue. Lower bone glue content resulted in poor adhesion and visible defects such as cracking and blistering. SEM analysis confirmed that higher bone glue content enhanced bonding between the ground layer and the wood substrate. Full article

Several molecules and extracts are known to have bone-specific effects. For example, the long-term use of glucocorticoids like prednisolone causes several negative effects including a loss of bone mass. Molecules like prednisolone are usually dissolved in organic solvent which are known to be toxic for zebrafish embryo in certain concentrations. Nevertheless, solvents like dimethyl sulfoxide (DMSO), ethanol and methanol have never been tested for specific skeletal effects during development in dose-dependency. Vitality assay, live fluorescence and bone-specific staining were used to evaluate solvents effects compared to prednisolone. DMSO, ethanol and methanol perturb osteogenesis starting from 1%, 1.5% and 3% respectively, concentrations in which vasculature, length and survival rate appear unaffected. This effect may be due to high sensitivity of the osteogenesis process to external chemical stimuli, especially in the trunk. On the contrary, the negative effect of prednisolone on skeletal development appears more specific since it is found at very low concentrations, far from any other developmental defects. The recommended solvent concentration to be used in zebrafish embryos osteogenesis assay was established in 0.5% for DMSO, 2% for methanol and 0.5% for ethanol. We recommend analyzing both head and trunk mineralization in zebrafish embryo osteogenesis assay. Full article