Synthetic 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.

The Benefits of a Rehabilitation Program Following Medial Patellofemoral Ligament Reconstruction

The medial patellofemoral ligament (MPFL) is critical for patellar stability. This study investigates the efficacy of a one-year physical therapy rehabilitation program following MPFL reconstruction using Synthetic Graft (SG) and Quadriceps Tendon Autograft (QTA). Thirty-five patients aged 18–38 underwent MPFL reconstruction (20 SG, 15 QTA). They participated in a structured rehabilitation program to improve their range of motion (ROM), muscle strength, pain management, and overall quality of life (QoL). The program included physiotherapy and MLS laser, Game Ready Therapy, EMS, TENS, TECAR, and lymphatic drainage. Before and after the program, assessments included knee flexion and extension using goniometry, muscle strength via the Medical Research Council (MRC) scale, knee circumference, pain intensity on the Visual Analogue Scale (VAS), and QoL with the EQ-5D instrument. Significant improvements were observed in knee flexion (37.57° vs. 114.71°, p < 0.001), muscle strength (MRC scale 1–4 points vs. 4–5 points, p < 0.001), and pain reduction (VAS 6.66 vs. 0.46, p < 0.001). The functional coefficient of mobility and QoL scores also markedly increased. Patients with QTA improved some parameters better than those with SG. These findings support the effectiveness of a comprehensive rehabilitation program in enhancing knee functionality, reducing pain, and improving QoL post-MPFL reconstruction. Personalized rehabilitation protocols are recommended to optimize recovery outcomes.

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.

Non-tuberculous mycobacterial bone and joint infections - a case series from a tertiary referral centre in Australia.

Non-tuberculous mycobacteria (NTM) are rare causes of bone and joint infection (BJI) and there is limited evidence on which to base management decisions. This study describes 1 year of experience from a multi-disciplinary BJI team which collects data on all cases reviewed at a tertiary referral centre in Queensland, Australia. The database was interrogated for all cases in which NTM were recovered from operative samples. Individual chart review was performed to collect the details of each case. A total of seven cases were managed between 1st February 2021 and 28th February 2022, comprising one patient with chronic osteomyelitis, three with fracture-related infections, two with prosthetic joint infections, and one with infection of a synthetic ligament graft. In contrast to pulmonary NTM infections, most patients were clinically well and immunocompetent, and most infections were propagated by direct inoculation. Time to diagnosis was unknown in three patients, with 1, 2, 2, and 5 months for the remaining four. Rapid growing NTM were diagnosed on routine cultures and specific mycobacterial cultures were confirmatory. Management was characterized by multiple stage surgical procedures and prolonged antimicrobial regimens. Antimicrobial complications were common; however, all patients were infection free at their latest follow up. Despite the inherent limitations, these results suggest that routinely ordering mycobacterial culture is of low yield. There is potential for shorter-term oral antimicrobial treatments. Prospective research is required to optimize treatment regimens and durations.

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.

Treatment with a self-expanding endoprosthesis in patients with stenosis or occlusion at the arteriovenous graft: 6-Month outcomes of a post-marketing surveillance study.

To assess 6-month safety and efficacy of a self-expanding stent graft placement to treat stenotic or thrombosed synthetic arteriovenous access graft at the venous anastomoses. This prospective, multicenter, post-market surveillance study assessed the GORE® VIABAHN® Endoprosthesis (stent graft) in Japanese patients with stenotic or thrombosed vascular access grafts. Key efficacy and safety outcomes were primary patency (PP) and secondary patency (SP) of the target lesion and the vascular access circuit, repeat interventions, technical and clinical success, incidence of adverse and serious adverse events, and device deficiencies through 6 months. The 103 enrolled patients (mean age 71.8 years; 57.3% female) had stent grafts placed in the venous anastomosis of arteriovenous access grafts (on-label). The majority of lesions were stenotic (77.1%) and located in the upper arm (91.4%). Mean lesion length was 42.9 ± 23.6 mm and diameter was 6.7 ± 1.9 mm; 28 patients (27.2%) had elephant trunk placements. Technical and clinical success rates were 100%. At 6 months, Kaplan-Meier estimates of target lesion and circuit PP were 75.1% (95% CI: 65.2, 82.6) and 66.8% (95% CI: 56.4, 75.3), and SP rates were 93.8% (95% CI: 86.7, 97.2) and 93.8% (95% CI: 86.7, 97.2), respectively. Mean cumulative number of reinterventions (0.36; 95% CI: 0.20, 0.51) and incidence of device- or procedure-related adverse events were low (⩽3%). No device deficiencies were reported. The 6-month outcomes of the self-expanding stent graft to treat thrombosed venous anastomoses of synthetic hemodialysis vascular access grafts with stenosis demonstrated safety and effectiveness.

Patellar Tendon Ruptures after Total Knee Arthroplasty.

Patellar tendon (PT) rupture following total knee arthroplasty (TKA) is a rare, but devastating complication. These injuries occur most frequently in the acute period following TKA due to trauma to the knee. PT ruptures that disrupt the extensor mechanism create a marked functional deficit, impacting every facet of daily life. In complete ruptures of the PT, repair or reconstruction is typically indicated; however, complication rates following intervention remain high. Operative intervention remains the mainstay of treatment, with only certain specific situations where nonoperative intervention is appropriate. Operative techniques are chosen based on the acuity, location of disruption, and status of the residual soft tissues. Treatment options include repair with or without augmentation or reconstruction. Augmentation does reduce the high risk of complications, bringing rates down from 63 to 25%. Augmentation options include autografts, allografts, synthetic grafts, or synthetic meshes. Despite advancements, outcomes are unpredictable and complications are common, highlighting the need for further research to improve treatment protocols. This article provides an overview of PT ruptures following TKA, the various treatment options, and the recommendations of the M.M., R.D., G.S. for each common type of PT injury encountered.

Regional Differences in Vascular Graft Degradation and Regeneration Contribute to Dilation.

Severe coronary artery disease is often treated with a coronary artery bypass graft using an autologous blood vessel. When this is not available, a commercially available synthetic graft can be used as an alternative but is associated with high failure rates and complications. Therefore, the research focus has shifted toward the development of biodegradable, regenerative vascular grafts that can convert into neoarteries. We previously developed an electrospun tropoelastin (TE)-polyglycerol sebacate (PGS) vascular graft that rapidly regenerated into a neoartery, with a cellular composition and extracellular matrix approximating the native aorta. We noted, however, that the TE-PGS graft underwent dilation until sufficient neotissue had been regenerated. This study investigated the mechanisms behind the observed dilation following TE-PGS vascular graft implantation in mice. We saw more pronounced dilation at the graft middle compared with the graft proximal and graft distal regions at 8 weeks postimplantation. Histological analysis revealed less degradation at the graft middle, although the remaining graft material appeared pitted, suggesting compromised structural and mechanical integrity. We also observed delayed cellular infiltration and extracellular matrix (ECM) deposition at the graft middle, corresponding with the area's reduced ability to resist dilation. In contrast, the graft proximal region exhibited greater degradation and significantly enhanced cellular infiltration and ECM regeneration. The nonuniform dilation was attributed to the combined effect of the regional differences in graft degradation and arterial regeneration. Consideration of these findings is crucial for graft optimization prior to its use in clinical applications.

Urgent hybrid repair of a symptomatic dissection-related type ii thoracoabdominal aortic aneurysms.

Emergency repair of type II thoraco-abdominal aortic aneurysms is burdened by high perioperative morbidity and mortality. We report the case of a symptomatic type II post-dissection thoraco-abdominal aortic aneurysm that was treated by mean of a hybrid technique. The repair was carried out through two stages. In the first stage, we deployed two imbricated stent grafts in the descending thoracic aorta. A left carotid to left subclavian artery by-pass was preemptively performed in order to obtain a proper proximal landing zone and as part of the spinal cord protective maneuvers. The endovascular first stage was effective in obtaining proximal sealing but, as expected, did not prevent distal reperfusion of the aneurysmatic false lumen. Few hours later, we moved on to the second stage in which we repaired the aneurysmal distal thoracic and abdominal aortic segment by mean of a multibranched synthetic graft. The repair was carried out through a left thoracophrenolaparotomy in the VII intercostal space. A left passive arterial by-pass and selective cold renal and warm visceral perfusion were adopted in order to provide organ protection. Technical success was achieved and radiologically confirmed. The patient experienced a mild postoperative paraplegia, which almost completely regressed after a neuro-motor rehabilitation program.

THE EFFECTIVENESS OF THE FUNCTIONING OF RECONSTRUCTED HEPATIC VEINS USING VARIOUS TYPES OF MATERIALS IN TRANSPLANTATION OF THE RIGHT LOBE OF THE LIVER FROM A LIVING DONOR

Background. In adult living donor liver transplantation with the right lobe, the venous outflow of the anterior sector is typically restored during the procedure to form a neo-middle hepatic vein. Restoring the middle hepatic vein for the drainage of the anterior sector is critically important for achieving optimal graft function. Various conduits are used for this reconstruction, such as synthetic and biological grafts (e.g., the recipient's portal vein, vessels from a deceased donor, and modified great saphenous vein). However, the selection of the best option remains a topic of discussion. This study evaluates the effectiveness of using biological and synthetic grafts for MHV reconstruction. Materials and methods. A retrospective analysis of outcomes was conducted in patients who underwent transplantation of a modified right liver lobe due to end-stage liver disease from 2011 to 2024. Results. A transplantation of modified right liver lobes was performed on 80 patients. In 69 cases, the reconstruction of the hepatic veins was carried out using a biological graft, while in 11 cases, a synthetic graft was used. Statistically significant differences were noted in mortality and the postoperative period. No significant differences were found in the frequency of intraoperative complications. Conclusion. Our study demonstrates that the use of a biological graft for the reconstruction of the hepatic veins of segments 5 and 8 is more effective than the application of a vascular prosthesis.

Acute lower limb ischemia caused by repeat deployment of vascular closure device.

Vascular closure devices are used to facilitate faster hemostasis and earlier ambulation, improve patient comfort, and reduce length of hospital stay after percutaneous endovascular procedures. However, their use may rarely be associated with limb ischemia due to endothelial damage and arterial thrombosis. This report illustrates the case of a patient who experienced acute lower limb ischemia due to superficial femoral artery occlusion caused by repeat closure with Angio-Seal vascular closure device within 30 days in a small-caliber superficial femoral artery. The patient was surgically treated by vascular repair with a synthetic graft, and remains symptom-free in 3-year follow-up. Repeat deployment of vascular closure devices in the same access site within a period of 30 days may cause acute limb ischemia due to arterial thrombosis, especially in patients with small-caliber arteries, even in the absence of evident risk factors.

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.

Assessment of decellularization strategy and biocompatibility testing of full-thickness abdominal wall to produce a tissue-engineered graft.

Restoration of the abdominal wall defects due to herniation or other complications represents a challenging task of the reconstructive surgery. Synthetic grafts or crosslinked animal-derived grafts, are utilized, followed by significant adverse reactions. This study aimed to evaluate primarily the production of a decellularized abdominal wall scaffold and secondly its biocompatibility upon transplantation in an animal model. Full-thickness abdominal wall samples were harvested from Wistar Rats and then decellularized utilizing a three-cycle process. To evaluate the decellularization efficacy, histological, biochemical and biomechanical analyses were performed. The biocompatibility assessment involved the implantation of the produced scaffolds to Sprague Dawley rats. The grafts remained for a total period of 4 weeks, followed by immunohistochemistry for the detection of CD11b+, CD4+ and CD8+ cells. Histological, biochemical and biomechanical results, indicated the production of compatible acellular full-thickness abdominal wall samples. After 4 weeks of implantation, a minor presence of immunity cells was observed. The data of this study indicated the successful production of a full-thickness abdominal wall scaffold. Biologically derived full-thickness abdominal wall scaffolds may have greater potential in restoration of the abdominal wall defects, bringing them one step closer to their clinical utility.

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.

Management Options for Traumatic Posterior Sternoclavicular Joint Dislocation: A Narrative Review with a Single Institution's Experience.

Background: Posterior sternoclavicular joint (SCJ) dislocations are rare events that can evolve into real emergencies due to the vital structures in the mediastinum. When closed reduction maneuvers fail, open SCJ reconstruction becomes mandatory, with literature proposing several stabilization techniques that either preserve or remove the SCJ's mobility. This study is a narrative review of the most recent literature regarding posterior trauma to the SCJ along with a single institution's experience of this pathology, managed either conservatively or surgically, with a figure-of-eight autologous semitendinosus graft in case of closed reduction failure. Methods: This article provides an overview of posterior traumatic SCJ dislocation, and it describes five cases of patients managed for traumatic posterior SCJ dislocation treated either conservatively or surgically with a figure-of-eight semitendinosus tendon autograft reinforced with high-strength suture tape. A comparison with the most recent literature is performed, focusing on biomechanics. Results: The demographics, the mechanism of injury, the management algorithm and the surgical strategy align with the most recent literature. Despite the final treatment, at one year of follow-up, the ROM was restored with full strength throughout the range of motion of the shoulder with no neurological deficits. The reduced joint successfully healed in imaging, and patients returned to their daily lives. The surgical site wounds and donor harvest sites were perfectly healed. Conclusions: Although recent recommendations for treating posterior traumatic SCJ dislocation have advanced, no universally accepted method of stabilization exists, and the surgical strategy is generally entrusted to the surgeon's experience. The literature still increasingly supports figure-of-eight ligament reconstruction with a biological or synthetic graft. This work further implements the literature by reporting good outcomes at follow-up.

Development of small-diameter vascular grafts using PCL/PLA/gelatin/PVA/hyaluronic acid nanofibers containing VEGF/enoxaparin

The extending demands for narrow-diameter vascular grafts to restore damaged arteries have captivated researcher's attention. The absence of appropriate vascular substitutes is due to the poor patency rate of small-caliber synthetic grafts caused by thrombosis and vessel hemodynamic mismatch that induce intimal hyperplasia. We developed small-diameter vascular grafts in two layers through electrospinning. The inner layer was fabricated by gelatin/polyvinyl alcohol (PVA)/hyaluronic acid/enoxaparin and vascular endothelial growth factor (VEGFs) and the outer layer was manufactured via polycaprolactone (PCL)/polylactic acid (PLA)/hyaluronic acid. The products were characterized by atomic force microscope (AFM), scanning electron microscope (SEM), water contact angle (WCA), attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), swelling test, mechanical test, and release rate. Blood compatibility tests including blood clotting time, hemolysis, and human platelet sedimentation were measured. The interactions of human umbilical vein endothelial cells (HUVECs) and human endometrial stem cells (hEnSCs) with nanofibrous vascular grafts were detected by SEM, viability assay, and DAPI staining. The results exhibited the produced small-diameter vascular grafts had proper antithrombotic properties due to two factors of VEGF and enoxaparin. After two months of the subcutaneous implantation of the scaffolds on the back of rats, the tubular vascular grafts lacked any macroscopic and histological signs of acute inflammation and had appropriate degradation rates. Furthermore, lumen patency was observed after 2 months. Consequently, VEGF and enoxaparin improves cell and blood compatibility in the small-diameter vascular grafts.

A Computational Framework to Optimize the Mechanical Behavior of Synthetic Vascular Grafts.

The failure of synthetic small-diameter vascular grafts has been attributed to a mismatch in the compliance between the graft and native artery, driving mechanisms that promote thrombosis and neointimal hyperplasia. Additionally, the buckling of grafts results in large deformations that can lead to device failure. Although design features can be added to lessen the buckling potential, the addition is detrimental to decreasing compliance (e.g., reinforcing coil). Herein, we developed a novel finite element framework to inform vascular graft design by evaluating compliance and resistance to buckling. A batch-processing scheme iterated across the multi-dimensional design parameter space, which included three parameters: coil thickness, modulus, and spacing. Three types of finite element models were created in FEBio for each unique coil-reinforced graft parameter combination to simulate pressurization, axial buckling, and bent buckling, and results were analyzed to quantify compliance, buckling load, and kink radius, respectively, from each model. Importantly, model validation demonstrated that model predictions agree qualitatively and quantitatively with experimental observations. Subsequently, data for each design parameter combination were integrated into an optimization function for which a minimum value was sought. The optimization values identified various candidate graft designs with promising mechanical properties. Our investigation successfully demonstrated the model-directed framework identified vascular graft designs with optimal mechanical properties, which can potentially improve clinical outcomes by addressing device failure. In addition, the presented computational framework promotes model-directed device design for a broad range of biomaterial and regenerative medicine strategies.

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.