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Bioengineering (Basel, Switzerland) Apr 2024To address the limitations of alginate and gelatin as separate hydrogels, partially oxidized alginate, alginate dialdehyde (ADA), is usually combined with gelatin to...
To address the limitations of alginate and gelatin as separate hydrogels, partially oxidized alginate, alginate dialdehyde (ADA), is usually combined with gelatin to prepare ADA-GEL hydrogels. These hydrogels offer tunable properties, controllable degradation, and suitable stiffness for 3D bioprinting and tissue engineering applications. Several processing variables affect the final properties of the hydrogel, including degree of oxidation, gelatin content and type of crosslinking agent. In addition, in 3D-printed structures, pore size and the possible addition of a filler to make a hydrogel composite also affect the final physical and biological properties. This study utilized datasets from 13 research papers, encompassing 33 unique combinations of ADA concentration, gelatin concentration, CaCl and microbial transglutaminase (mTG) concentrations (as crosslinkers), pore size, bioactive glass (BG) filler content, and one identified target property of the hydrogels, stiffness, utilizing the Extreme Boost (XGB) machine learning algorithm to create a predictive model for understanding the combined influence of these parameters on hydrogel stiffness. The stiffness of ADA-GEL hydrogels is notably affected by the ADA to GEL ratio, and higher gelatin content for different ADA gel concentrations weakens the scaffold, likely due to the presence of unbound gelatin. Pore size and the inclusion of a BG particulate filler also have a significant impact on stiffness; smaller pore sizes and higher BG content lead to increased stiffness. The optimization of ADA-GEL composition and the inclusion of BG fillers are key determinants to tailor the stiffness of these 3D printed hydrogels, as found by the analysis of the available data.
PubMed: 38790283
DOI: 10.3390/bioengineering11050415 -
Medical Engineering & Physics Jun 2024Mass transport properties within three-dimensional (3D) scaffold are essential for tissue regeneration, such as various fluid environmental cues influence mesenchymal...
Mass transport properties within three-dimensional (3D) scaffold are essential for tissue regeneration, such as various fluid environmental cues influence mesenchymal stem cells differentiation. Recently, 3D printing has been emerging as a new technology for scaffold fabrication by controlling the scaffold pore geometry to affect cell growth environment. In this study, the flow field within scaffolds in a perfusion system was investigated with uniform structures, single gradient structures and complex gradient structures using computational fluid dynamics (CFD) method. The CFD results from those uniform structures indicate the fluid velocity and fluid shear stress within the scaffold structure increased as the filament diameter increasing, pore width decreasing, pore shape decreased from 90° to 15°, and layer configuration changing from lattice to stagger structure. By assembling those uniform structure as single gradient structures, it is noted that the fluid dynamic characterisation within the scaffold remains the same as the corresponding uniform structures. A complex gradient structure was designed to mimic natural osteochondral tissue by assembly the uniform structures of filament diameter, pore width, pore shape and layer configuration. The results show that the fluid velocity and fluid shear stress within the complex gradient structure distribute gradually increasing and their maximum magnitude were from 1.15 to 3.20 mm/s, and from 12 to 39 mPa, respectively. CFD technique allows the prediction of velocity and fluid shear stress within the designed 3D gradient scaffolds, which would be beneficial for the tissue scaffold development for interfacial tissue engineering in the future.
Topics: Hydrodynamics; Printing, Three-Dimensional; Tissue Engineering; Tissue Scaffolds; Porosity; Stress, Mechanical; Computer Simulation
PubMed: 38789213
DOI: 10.1016/j.medengphy.2024.104173 -
Clinics in Podiatric Medicine and... Jul 2024Osteochondral lesions of the talus are a common sequelae of trauma and are often associated with ankle sprains and ankle fractures. Because the surface of the talus is... (Review)
Review
Osteochondral lesions of the talus are a common sequelae of trauma and are often associated with ankle sprains and ankle fractures. Because the surface of the talus is composed primarily of hyaline cartilage, the regenerative capacity of these injuries is limited. Therefore, several open and arthroscopic techniques have been described to treat osteochondral injuries of the talus and underlying bone marrow lesions. Throughout this review, these treatment options are discussed along with their indications and currently reported outcomes. A commentary on the authors' preferences among these techniques is also provided.
Topics: Humans; Talus; Arthroscopy; Cartilage, Articular; Ankle Injuries; Male; Female
PubMed: 38789163
DOI: 10.1016/j.cpm.2024.01.004 -
Medicine May 2024Osteochondral lesions on the lateral process of the talus involving the subtalar joint are rare; the optimal surgical treatment remains to be clarified as there are few...
RATIONALE
Osteochondral lesions on the lateral process of the talus involving the subtalar joint are rare; the optimal surgical treatment remains to be clarified as there are few reports. Additionally, bilateral cases are extremely rare. Therefore, the clinical outcomes of the surgical treatment for bilateral osteochondral lesions on the lateral process of the talus involving the subtalar joint have not been fully elucidated.
PATIENT CONCERNS
A 16-year-old boy who played soccer presented to our hospital with bilateral hindfoot pain. The symptoms persisted even after 3 months of conservative treatment. The patient and family requested surgical treatment to relieve the symptoms.
DIAGNOSES
The patient was diagnosed with bilateral osteochondral lesions on the lateral process of the talus, involving the subtalar joint based on computed tomography and magnetic resonance imaging findings.
INTERVENTIONS
Arthroscopic debridement and microfracture were performed bilaterally.
OUTCOMES
Postoperative computed tomography and magnetic resonance imaging of both feet revealed remodeling of the subchondral bone. The patient returned to play at the pre-injury level with no pain.
LESSONS
This report describes a case of bilateral osteochondral lesions on the lateral process of the talus, involving the subtalar joint. Arthroscopic debridement and microfracture were effective in relieving symptoms and the subchondral bone remodeling. To the best of our knowledge, this is the first report of arthroscopic treatment of osteochondral lesions of the lateral process of the talus involving the subtalar joint.
Topics: Humans; Male; Adolescent; Debridement; Talus; Subtalar Joint; Arthroscopy; Magnetic Resonance Imaging; Soccer; Tomography, X-Ray Computed; Arthroplasty, Subchondral
PubMed: 38787984
DOI: 10.1097/MD.0000000000038302 -
Journal of Orthopaedic Case Reports May 2024Transplantation with fresh cadaveric osteochondral allograft (FOCA) is frequently used in defects of the femoral condyle and tibial plateau to preserve the knee joint....
INTRODUCTION
Transplantation with fresh cadaveric osteochondral allograft (FOCA) is frequently used in defects of the femoral condyle and tibial plateau to preserve the knee joint. However, the use of FOCA in bipolar lesions remains controversial in cases with bipolar defects and a history of infection.
CASE REPORT
We present a 21-year-old male patient with a massive post-traumatic osteochondral defect of the lateral compartment of the knee and a history of infection, treated by a two-stage approach. In stage 1, infection was eradicated, and joint function recovered with aggressive debridement, polymethyl methacrylate beads, bone cement spacers, and Judet's quadricepsplasty. In stage 2, transplantation was performed with a bipolar FOCA. All treatments were planned using 3D-printed models.
CONCLUSION
The two-stage approach and 3D planning can increase the chances of transplant success by preparing the future allograft bed and obtaining an optimal match between the cadaveric allograft and the patient's defect in cases with potential contraindications, such as a bipolar lesion in the femoral condyle and tibial plateau and a history of infection. A combined approach may lead to a more beneficial outcome for the patient to preserve joint function and improve quality of life.
PubMed: 38784883
DOI: 10.13107/jocr.2024.v14.i05.4452 -
The Orthopedic Clinics of North America Jul 2024Although the impact that vitamin D has on bone healing is uncertain in foot and ankle (F&A) surgery, there is support for vitamin D supplementation (2000 IU/day) with... (Review)
Review
Although the impact that vitamin D has on bone healing is uncertain in foot and ankle (F&A) surgery, there is support for vitamin D supplementation (2000 IU/day) with calcium (1 g/day) to promote bone healing. Although orthopedic F&A surgeons are frequently the first provider to detect the harbingers of osteoporosis by the occurrence of fragility fractures, this should trigger referral to the appropriate specialist for assessment and treatment. There is circumstantial evidence suggesting a role of hypovitaminosis D in bone marrow edema syndrome and possibly osteochondritis dissecans. There should be a low threshold for assessing vitamin D levels in such patients.
Topics: Humans; Vitamin D; Vitamin D Deficiency; Dietary Supplements; Orthopedic Procedures; Foot; Ankle
PubMed: 38782509
DOI: 10.1016/j.ocl.2024.01.002 -
The Journal of Craniofacial Surgery May 2024Septal extension graft (SEG) is an adaptable tool that controls, supports, and stabilizes the nasal tip projection, rotation, length, and shape. Recent studies comparing...
Septal extension graft (SEG) is an adaptable tool that controls, supports, and stabilizes the nasal tip projection, rotation, length, and shape. Recent studies comparing SEGs to more conventional columellar strut grafts found that SEGs provided improved results. This prospective cohort study included 66 patients divided into 2 groups based on their indications. Group 1 was patients who underwent septorhinoplasty using osteochondral septal extension graft (OSEG), and group 2 underwent septorhinoplasty using cartilaginous SEG. The main reason for undergoing OSEG was insufficient septal cartilage (P<0.001). The outcomes were not significantly different between both groups, with the % of patients who experienced positive outcomes ranging from 78.8% to 97%. The OSEG is a safe, valid, and effective option in septorhinoplasty that can be used in patients with insufficient cartilaginous septum.
PubMed: 38781431
DOI: 10.1097/SCS.0000000000010324 -
Biomaterials Sep 2024The gel microsphere culture system (GMCS) showed various advantages for mesenchymal stem cell (MSC) expansion and delivery, such as high specific surface area, small and...
The gel microsphere culture system (GMCS) showed various advantages for mesenchymal stem cell (MSC) expansion and delivery, such as high specific surface area, small and regular shape, extensive adjustability, and biomimetic properties. Although various technologies and materials have been developed to promote the development of gel microspheres, the differences in the biological status of MSCs between the GMCS and the traditional Petri dish culture system (PDCS) are still unknown, hindering gel microspheres from becoming a culture system as widely used as petri dishes. In the previous study, an excellent "all-in-one" GMCS has been established for the expansion of human adipose-derived MSCs (hADSCs), which showed convenient cell culture operation. Here, we performed transcriptome and proteome sequencing on hADSCs cultured on the "all-in-one" GMCS and the PDCS. We found that hADSCs cultured in the GMCS kept in an undifferentiation status with a high stemness index, whose transcriptome profile is closer to the adipose progenitor cells (APCs) in vivo than those cultured in the PDCS. Further, the high stemness status of hADSCs in the GMCS was maintained through regulating cell-ECM interaction. For application, bilayer scaffolds were constructed by osteo- and chondro-differentiation of hADSCs cultured in the GMCS and the PDCS. The effect of osteochondral regeneration of the bilayer scaffolds in the GMCS group was better than that in the PDCS group. This study revealed the high stemness and excellent functionality of MSCs cultured in the GMCS, which promoted the application of gel microspheres in cell culture and tissue regeneration.
Topics: Microspheres; Humans; Mesenchymal Stem Cells; Adipose Tissue; Cell Differentiation; Animals; Extracellular Matrix; Cells, Cultured; Tissue Scaffolds; Gels; Chondrogenesis; Osteogenesis; Cell Culture Techniques
PubMed: 38776592
DOI: 10.1016/j.biomaterials.2024.122616 -
Journal of Orthopaedic Translation May 2024Osteochondral regeneration has long been recognized as a complex and challenging project in the field of tissue engineering. In particular, reconstructing the...
BACKGROUND
Osteochondral regeneration has long been recognized as a complex and challenging project in the field of tissue engineering. In particular, reconstructing the osteochondral interface is crucial for determining the effectiveness of the repair. Although several artificial layered or gradient scaffolds have been developed recently to simulate the natural interface, the functions of this unique structure have still not been fully replicated. In this paper, we utilized laser micro-patterning technology (LMPT) to modify the natural osteochondral "plugs" for use as grafts and aimed to directly apply the functional interface unit to repair osteochondral defects in a goat model.
METHODS
For in vitro evaluations, the optimal combination of LMPT parameters was confirmed through mechanical testing, finite element analysis, and comparing decellularization efficiency. The structural and biological properties of the laser micro-patterned osteochondral implants (LMP-OI) were verified by measuring the permeability of the interface and assessing the recellularization processes. In the goat model for osteochondral regeneration, a conical frustum-shaped defect was specifically created in the weight-bearing area of femoral condyles using a customized trephine with a variable diameter. This unreported defect shape enabled the implant to properly self-fix as expected.
RESULTS
The micro-patterning with the suitable pore density and morphology increased the permeability of the LMP-OIs, accelerated decellularization, maintained mechanical stability, and provided two relative independent microenvironments for subsequent recellularization. The LMP-OIs with goat's autologous bone marrow stromal cells in the cartilage layer have securely integrated into the osteochondral defects. At 6 and 12 months after implantation, both imaging and histological assessments showed a significant improvement in the healing of the cartilage and subchondral bone.
CONCLUSION
With the natural interface unit and zonal recellularization, the LMP-OI is an ideal scaffold to repair osteochondral defects especially in large animals.
THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE
These findings suggest that such a modified xenogeneic osteochondral implant could potentially be explored in clinical translation for treatment of osteochondral injuries. Furthermore, trimming a conical frustum shape to the defect region, especially for large-sized defects, may be an effective way to achieve self-fixing for the implant.
PubMed: 38774916
DOI: 10.1016/j.jot.2024.04.005 -
Foot & Ankle International May 2024Bone marrow stimulation (BMS) is presently considered first-line surgical treatment for osteochondral lesions of the talus (OLTs); however, some patients still...
BACKGROUND
Bone marrow stimulation (BMS) is presently considered first-line surgical treatment for osteochondral lesions of the talus (OLTs); however, some patients still experience pain or dysfunction after surgery, and the reasons for success or failure remain somewhat unclear. This study aimed to investigate the effect of smoking on postoperative outcomes after arthroscopic BMS for OLTs.
METHODS
Consecutive patients with OLTs who underwent BMS between January 2017 and January 2020 were included. Smokers were defined as patients who actively consumed cigarettes before surgery and postoperatively, whereas nonsmokers were patients who never smoked. Visual analog scale (VAS), American Orthopaedic Foot & Ankle Society ankle hindfoot score (AOFAS), Karlsson-Peterson, and Tegner scores were assessed preoperatively and at follow-up. Additionally, a general linear model (GLM) was performed, followed by the interaction analysis to explore the potential influence of smoking.
RESULTS
The study enrolled 104 patients with a mean follow-up of 30.91 ± 7.03 months, including 28 smokers and 76 nonsmokers. There were no significant differences in patient age (35.2 ± 10.0 years vs 37.6 ± 9.7 years, = .282) or OLT area (63.7 ± 38.7 mm vs 52.8 ± 37.0 mm, = .782). Both univariate analysis and GLM revealed that smoking was associated with worse postoperative pain levels, Karlsson-Peterson, and AOFAS scores ( < .05). The interaction analysis showed a significant interaction between smoking and OLT area for postoperative Karlsson-Peterson scores (general ankle function) ( = .031). Simple main effects analysis revealed that the negative effect of smoking on Tegner score significantly increased among patients >32 years old or with OLT area>50 mm ( < .05).
CONCLUSION
Smoking was associated with worse clinical outcomes following BMS of OLTs. As the size of OLTs increased, the difference in general ankle function between smokers and nonsmokers also increased. Furthermore, smokers who were older than 32 years or had larger OLTs were less likely to resume participation in high-level activities.
PubMed: 38770767
DOI: 10.1177/10711007241250007