OBJECTIVES: To evaluate the osteogenic efficacy of three-dimensional printing individualized titanium mesh (3D-PITM) as a scaffold material in guided bone regeneration (GBR). METHODS: 1) Patients undergoing GBR for alveolar bone defects were enrolled as study subjects, and postoperative healing complications were recorded. 2) Postoperative cone beam computed tomography (CBCT) scans acquired at least 6 months post-surgery were used to calculate the percentage of actual bone formation volume. 3) Alveolar bone specimens were collected during the first-stage implant surgery for histomorphometric analysis. This analysis quantitatively measured the proportions of newly formed bone and newly formed unmineralized bone within the specimens. Specimens were categorized into three groups based on healing complications (good healing group, wound dehiscence group, 3D-PITM exposure group) to compare differences in the proportions of newly formed bone and newly formed unmineralized bone. RESULTS: 1) Twelve patients were included. Guided bone regeneration failed in one patient, and 3D-PITM exposure occurred in three patients (exposure rate: 25%). 2) The mean percentage of actual bone formation volume in the 11 successful guided bone regeneration cases was 95.23%±28.85%. 3) Histomorphometric analysis revealed that newly formed bone constituted 40.35% of the alveolar bone specimens, with newly formed unmineralized bone accounting for 13.84% of the newly formed bone. Intergroup comparisons showed no statistically significant differences (P>0.05) in the proportions of newly formed bone or newly formed unmineralized bone between the good healing group and the wound dehiscence group or the 3D-PITM exposure group. CONCLUSIONS 3D-PITM enables effective bone augmentation. Radiographic assessment demonstrated favorable bone formation volume, while histological analysis confirmed substantial formation of newly formed mineralized bone within the surgical site.
Humans ; Printing, Three-Dimensional ; Titanium ; Cone-Beam Computed Tomography ; Bone Regeneration ; Osteogenesis ; Surgical Mesh ; Tissue Scaffolds ; Alveolar Process/surgery* ; Adult ; Male ; Middle Aged ; Female ; Wound Healing ; Guided Tissue Regeneration, Periodontal/methods* ; Alveolar Bone Loss/surgery*

OBJECTIVES: This study investigated the effects of a polycaprolactone (PCL)-polyethylene glycol (PEG) scaffold incorporated with concentrated growth factor (CGF) on the adhesion, proliferation, and osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs). METHODS: The PCL-PEG-CGF composite scaffold was fabricated using an immersion and freeze-drying technique. Its microstructure, mechanical properties, and biocompatibility were systematically characterized. The hPDLSCs were isolated through enzymatic digestion, and the hPDLSCs were identified through flow cytometry. Third-passage hPDLSCs were seeded onto the composite scaffolds, and their adhesion, proliferation and osteogenic differentiation were assessed using CCK-8 assays, 4',6-diamidino-2-phenylindole (DAPI) staining, alkaline phosphatase (ALP) staining, alizarin red staining, and Western blot analysis of osteogenesis-related proteins [Runt-related transcription factor 2 (Runx2), ALP, and morphogenetic protein 2 (BMP2)]. RESULTS: Scanning electron microscopy revealed that the PCL-PEG-CGF composite scaffold exhibited a honeycomb-like structure with heterogeneous pore sizes. The composite scaffold exhibited excellent hydrophilicity, as evidenced by a contact angle (θ) approaching 0° within 6 s. Its elastic modulus was measured at (4.590 0±0.149 3) MPa, with comparable hydrophilicity, fracture tensile strength, and fracture elongation to PCL-PEG scaffold. The hPDLSCs exhibited significantly improved adhesion to the PCL-PEG-CGF composite scaffold compared with the PCL-PEG scaffold (P<0.01). Additionally, cell proliferation was markedly improved in all the experimental groups on days 3, 5, and 7 (P<0.01), and statistically significant differences were found between the PCL-PEG-CGF group and other groups (P<0.01). The PCL-PEG-CGF group showed significantly elevated ALP activity (P<0.05), increased mineralization nodule formation, and upregulated expression of osteogenic-related proteins (Runx2, BMP2 and ALP; P<0.05). CONCLUSIONS The PCL-PEG-CGF composite scaffold exhibited excellent mechanical properties and biocompatibility, enhancing the adhesion and proliferation of hPDLSCs and promoting their osteogenic differentiation by upregulating osteogenic-related proteins.
Humans ; Polyesters/chemistry* ; Periodontal Ligament/cytology* ; Polyethylene Glycols/chemistry* ; Stem Cells/cytology* ; Tissue Scaffolds ; Cell Proliferation ; Osteogenesis ; Cell Differentiation ; Cell Adhesion ; Bone Morphogenetic Protein 2/metabolism* ; Cells, Cultured ; Alkaline Phosphatase/metabolism* ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Intercellular Signaling Peptides and Proteins/pharmacology* ; Tissue Engineering/methods*

Organoids are three-dimensional (3D) cellular structures formed through the differentiation and self-organization of pluripotent stem cells or tissue-derived cells, showing considerable potential in the research on disease mechanism, personalized medicine, and developmental biology. However, the development of organoids is limited by the complex composition, batch-to-batch variations, and immunogenicity of basement-membrane matrix in the current culture system, which hinders the clinical translation and in vivo applications of organoids. Hydrogels are highly hydrated 3D polymer network materials, with modifiable mechanical and biochemical properties by engineering, representing an ideal alternative to basement-membrane matrix. This article reviews the research progress in engineered hydrogels with defined composition currently used in organoid culture. We introduce the structural characteristics and engineering design considerations of hydrogels, emphasize the latest research progress and specific application cases, and discuss the future development of these engineered hydrogels, provide valuable insights for the further advancement and optimization of engineered hydrogels for organoid.
Hydrogels/chemistry* ; Organoids/cytology* ; Tissue Engineering/methods* ; Humans ; Animals ; Pluripotent Stem Cells/cytology* ; Cell Culture Techniques, Three Dimensional/methods* ; Tissue Scaffolds

In recent years, the rapid development of transportation and sports industries, coupled with the accelerated population aging in China, has led to a steady increase in the incidence of articular cartilage injuries, wear, and degenerative changes. Currently, the clinical treatment options for cartilage defects primarily include conservative therapies and surgical interventions, both of which have certain limitations. Cartilage tissue engineering (CTE), as a novel technology, provides an infinite prospect for cartilage regeneration and repair. Because of the abilities of scaffolds to mimic the natural cartilage structure, exhibit excellent biocompatibility and biomimetic mechanical properties, and promote cell adhesion and proliferation, scaffolds are considered effective delivery systems for growth factors, genes, and drugs. This review summarizes the clinical treatments for cartilage defects and their limitations, discusses the materials and preparation techniques of scaffolds used in CTE, with a particular focus on drug-loaded scaffold delivery systems in cartilage repair and regeneration, and offers a perspective on the future application of drug-loaded CTE. The aim is to provide theoretical guidance and new approaches for the repair of cartilage defects.
Tissue Engineering/methods* ; Humans ; Tissue Scaffolds ; Drug Delivery Systems/methods* ; Regeneration ; Cartilage, Articular/physiology* ; Animals ; Biocompatible Materials

To assess the implantation effectiveness of porous scaffolds, it is essential to consider not only their mechanical properties but also their biological performance. Given the high cost, long duration and low reproducibility of biological experiments, simulation studies as a virtual alternative, have become a widely adopted and efficient evaluation method. In this study, based on the secondary development environment of finite element analysis software, the strain energy density growth criterion for bone tissue was introduced to simulate and analyze the cell proliferation-promoting effects of four different lattice porous scaffolds under cyclic compressive loading. The biological performance of these scaffolds was evaluated accordingly. The computational results indicated that in the early stages of bone growth, the differences in bone tissue formation among the scaffold groups were not significant. However, as bone growth progressed, the scaffold with a porosity of 70% and a pore size of 900 μm demonstrated markedly superior bone formation compared to other porosity groups and pore size groups. These results suggested that the scaffold with a porosity of 70% and a pore size of 900 μm was most conducive to bone tissue growth and could be regarded as the optimal structural parameter for bone repair scaffold. In conclusion, this study used a visualized simulation approach to pre-evaluate the osteogenic potential of porous scaffolds, aiming to provide reliable data support for the optimized design and clinical application of implantable scaffolds.
Tissue Scaffolds/chemistry* ; Porosity ; Finite Element Analysis ; Tissue Engineering/methods* ; Computer Simulation ; Bone Development ; Osteogenesis ; Humans ; Cell Proliferation

The three-dimensional (3D) printed bone tissue repair guide scaffold is considered a promising method for treating bone defect repair. In this experiment, chitosan (CS), sodium alginate (SA), and mineralized collagen (MC) were combined and 3D printed to form scaffolds. The experimental results showed that the printability of the scaffold was improved with the increase of chitosan concentration. Infrared spectroscopy analysis confirmed that the scaffold formed a cross-linked network through electrostatic interaction between chitosan and sodium alginate under acidic conditions, and X-ray diffraction results showed the presence of characteristic peaks of hydroxyapatite, indicating the incorporation of mineralized collagen into the scaffold system. In the in vitro collagen release experiments, a weakly alkaline environment was found to accelerate the release rate of collagen, and the release amount increased significantly with a lower concentration of chitosan. Cell experiments showed that scaffolds loaded with mineralized collagen could significantly promote cell proliferation activity and alkaline phosphatase expression. The subcutaneous implantation experiment further verified the biocompatibility of the material, and the implantation of printed scaffolds did not cause significant inflammatory reactions. Histological analysis showed no abnormal pathological changes in the surrounding tissues. Therefore, incorporating mineralized collagen into sodium alginate/chitosan scaffolds is believed to be a new tissue engineering and regeneration strategy for achieving enhanced osteogenic differentiation through the slow release of collagen.
Chitosan/chemistry* ; Alginates/chemistry* ; Tissue Scaffolds/chemistry* ; Printing, Three-Dimensional ; Osteogenesis ; Collagen/chemistry* ; Cell Differentiation ; Animals ; Tissue Engineering/methods* ; Cell Proliferation ; Biocompatible Materials ; Glucuronic Acid/chemistry* ; Hexuronic Acids/chemistry*

OBJECTIVE: To summarize the research progress of bioactive scaffolds in the repair and regeneration of osteoporotic bone defects. METHODS: Recent literature on bioactive scaffolds for the repair of osteoporotic bone defects was reviewed to summarize various types of bioactive scaffolds and their associated repair methods. RESULTS: The application of bioactive scaffolds provides a new idea for the repair and regeneration of osteoporotic bone defects. For example, calcium phosphate ceramics scaffolds, hydrogel scaffolds, three-dimensional (3D)-printed biological scaffolds, metal scaffolds, as well as polymer material scaffolds and bone organoids, have all demonstrated good bone repair-promoting effects. However, in the pathological bone microenvironment of osteoporosis, the function of single-material scaffolds to promote bone regeneration is insufficient. Therefore, the design of bioactive scaffolds must consider multiple factors, including material biocompatibility, mechanical properties, bioactivity, bone conductivity, and osteogenic induction. Furthermore, physical and chemical surface modifications, along with advanced biotechnological approaches, can help to improve the osteogenic microenvironment and promote the differentiation of bone cells. CONCLUSION With advancements in technology, the synergistic application of 3D bioprinting, bone organoids technologies, and advanced biotechnologies holds promise for providing more efficient bioactive scaffolds for the repair and regeneration of osteoporotic bone defects.
Humans ; Tissue Scaffolds/chemistry* ; Bone Regeneration ; Osteoporosis/therapy* ; Tissue Engineering/methods* ; Biocompatible Materials/chemistry* ; Printing, Three-Dimensional ; Calcium Phosphates/chemistry* ; Osteogenesis ; Ceramics ; Cell Differentiation ; Hydrogels ; Bioprinting ; Bone and Bones

OBJECTIVE: To summarize the latest research progress of graphene and its derivatives (GDs) in bone repair. METHODS: The relevant research literature at home and abroad in recent years was extensively accessed. The properties of GDs in bone repair materials, including mechanical properties, electrical conductivity, and antibacterial properties, were systematically summarized, and the unique advantages of GDs in material preparation, functionalization, and application, as well as the contributions and challenges to bone tissue engineering, were discussed. RESULTS: The application of GDs in bone repair materials has broad prospects, and the functionalization and modification technology effectively improve the osteogenic activity and material properties of GDs. GDs can induce osteogenic differentiation of stem cells through specific signaling pathways and promote osteogenic activity through immunomodulatory mechanisms. In addition, the parameters of GDs have significant effects on the cytotoxicity and degradation behavior. CONCLUSION GDs has great potential in the field of bone repair because of its excellent physical and chemical properties and biological properties. However, the cytotoxicity, biodegradability, and functionalization strategies of GDs still need to be further studied in order to achieve a wider application in the field of bone tissue engineering.
Graphite/pharmacology* ; Tissue Engineering/methods* ; Humans ; Osteogenesis/drug effects* ; Biocompatible Materials/pharmacology* ; Bone Regeneration ; Tissue Scaffolds/chemistry* ; Cell Differentiation ; Bone and Bones ; Bone Substitutes/chemistry* ; Animals

OBJECTIVE: To prepare decellularized nerve grafts from alpha-1, 3-galactosyltransferase (GGTA1) gene-edited pigs and explore their biocompatibility for xenotransplantation. METHODS: The sciatic nerves from wild-type pigs and GGTA1 gene-edited pigs were obtained and underwent decellularization. The alpha-galactosidase (α-gal) content in the sciatic nerves of GGTA1 gene-edited pigs was detected by using IB4 fluorescence staining and ELISA method to verify the knockout status of the GGTA1 gene, and using human sciatic nerve as a control. HE staining and scanning electron microscopy observation were used to observe the structure of the nerve samples. Immunofluorescence staining and DNA content determination were used to evaluate the degree of decellularization of the nerve samples. Fourteen nude mice were taken, and subcutaneous capsules were prepared on both sides of the spine. Decellularized nerve samples of wild-type pigs ( n=7) and GGTA1 gene-edited pigs ( n=7) were randomly implanted in the subcutaneous capsules. Blood was drawn at 1, 3, 5, and 7 days after implantation to detect neutrophil counting. RESULTS: IB4 fluorescence staining and ELISA detection showed that GGTA1 gene was successfully knocked out in the nerves of GGTA1 gene-edited pigs. HE staining showed that the structure of the decellularized nerve from GGTA1 gene-edited pigs was well preserved; the nerve basement membrane tube structure was visible under scanning electron microscopy; no cell nuclei was observed, and the extracellular matrix components was retained in the nerve grafts by immunofluorescence staining; and the DNA content was significantly reduced when compared with the normal nerves ( P<0.05). In vivo experiments showed that the number of neutrophils in the two groups were similar at 1, 3, and 7 days after implantation, with no significant difference ( P>0.05); only at 5 days, the number of neutrophils was significantly lower in the GGTA1 gene-edited pigs than in the wild-type pigs ( P<0.05). CONCLUSION The decellularized nerve grafts from GGTA1 gene-edited pigs have well-preserved nerve structure, complete decellularization, retain the natural nerve basement membrane tube structure and components, and low immune response after xenotransplantation through in vitro experiments.
Animals ; Transplantation, Heterologous ; Galactosyltransferases/genetics* ; Sciatic Nerve/immunology* ; Swine ; Tissue Engineering/methods* ; Humans ; Graft Rejection/prevention & control* ; Gene Editing ; Mice ; Mice, Nude ; Heterografts/immunology* ; Animals, Genetically Modified ; Tissue Scaffolds ; Decellularized Extracellular Matrix

OBJECTIVE: To review the latest research advancements in surgical techniques for the treatment of limb lymphedema. METHODS: The relevant literature at home and abroad in recent years was extensively reviewed, and the research on the treatment of limb lymphedema by surgical techniques were summarized and analyzed. RESULTS: Lymphovenous anastomosis has demonstrated good effectiveness for early to mid-stage limb lymphedema, however its long-term effectiveness and applicability for late-stage limb lymphedema still require further validation. Autologous lymphatic/venous grafting has shown clinical feasibility in the treatment of secondary limb lymphedema. Research on tissue-engineered lymphatic scaffolds remains insufficient, primarily due to the complexity of lymphatic anatomical structures and the technical challenges involved. Nevertheless, its potential application is promising. Vascularized lymph node flap transplantation has shown significant effectiveness in treating limb lymphedema, particularly yielding good outcomes in upper limb cases. However, it can not guarantee a complete cure for the condition. Charles' operation is the most effective treatment option for patients with late-stage limb lymphedema, but its extensive incision and severe postoperative complications limit its application. Liposuction has the advantages such as minimal invasiveness, high safety, and repeatability. It is suitable for patients with late-stage limb lymphedema who have failed conservative treatment or developed adiposity. However, its effectiveness is limited in patients with significant limb fibrosis. CONCLUSION Current treatments for limb lymphedema require further improvement, and there is considerable debate regarding treatment strategies for different stages of the condition. Future high-quality, multi-system combined treatment approaches are anticipated to guide clinical practice.
Humans ; Lymphedema/surgery* ; Surgical Flaps/blood supply* ; Lymphatic Vessels/surgery* ; Anastomosis, Surgical/methods* ; Lymph Nodes/transplantation* ; Lipectomy/methods* ; Extremities/surgery* ; Treatment Outcome ; Tissue Engineering ; Tissue Scaffolds ; Veins/transplantation*