Pulpitis, periodontitis, jaw bone defect, and temporomandibular joint damage are common oral and maxillofacial diseases in clinic, but traditional treatments are unable to restore the structure and function of the injured tissues. Due to their good biocompatibility, biodegradability, antioxidant effect, anti-inflammatory activity, and broad-spectrum antimicrobial property, chitosan-based hydrogels have shown broad applicable prospects in the field of oral tissue engineering. Quaternization, carboxymethylation, and sulfonation are common chemical modification strategies to improve the physicochemical properties and biological functions of chitosan-based hydrogels, while the construction of hydrogel composite systems via carrying porous microspheres or nanoparticles can achieve local sequential delivery of diverse drugs or bioactive factors, laying a solid foundation for the well-organized regeneration of defective tissues. Chemical cross-linking is commonly employed to fabricate irreversible permanent chitosan gels, and physical cross-linking enables the formation of reversible gel networks. Representing suitable scaffold biomaterials, several chitosan-based hydrogels transplanted with stem cells, growth factors or exosomes have been used in an attempt to regenerate oral soft and hard tissues. Currently, remarkable advances have been made in promoting the regeneration of pulp-dentin complex, cementum-periodontium-alveolar bone complex, jaw bone, and cartilage. However, the clinical translation of chitosan-based hydrogels still encounters multiple challenges. In future, more in vivo clinical exploration under the conditions of oral complex microenvironments should be performed, and the combined application of chitosan-based hydrogels and a variety of bioactive factors, biomaterials, and state-of-the-art biotechnologies can be pursued in order to realize multifaceted complete regeneration of oral tissue.
Chitosan/chemistry* ; Tissue Engineering ; Hydrogels/chemistry* ; Biocompatible Materials/chemistry* ; Cartilage ; Tissue Scaffolds/chemistry*

Cartilage has poor self-recovery because of its characteristics of no blood vessels and high extracellular matrix. In clinical treatment, physical therapy or drug therapy is usually used for mild cartilage defects, and surgical treatment is needed for severe ones. In recent years, cartilage tissue engineering technology provides a new way for the treatment of cartilage defects. Compared with the traditional surgical treatment, cartilage tissue engineering technology has the advantages of small wound and good recovery. The application of microcarrier technology in the design of tissue engineering scaffolds further expands the function of scaffolds and promotes cartilage regeneration. This review summarized the main preparation methods and development of microcarrier technology in recent years. Subsequently, the properties and specific application scenarios of microcarriers with different materials and functions were introduced according to the materials and functions of microcarriers used in cartilage repair. Based on our research on osteochondral integrated layered scaffolds, we proposed an idea of optimizing the performance of layered scaffolds through microcarriers, which is expected to prepare bionic scaffolds that are more suitable for the structural characteristics of natural cartilage.
Cartilage ; Extracellular Matrix/chemistry* ; Technology ; Tissue Engineering/methods* ; Tissue Scaffolds/chemistry*

It is currently reported that extracellular matrix, biological scaffolds, conditions of stress, nutrients and metabolic waste play very important roles in tissue-engineered osteochondral composite. In this paper, we have made a review of their effects on such composite.
Cartilage ; chemistry ; physiology ; Chondrocytes ; Connective Tissue ; growth & development ; Extracellular Matrix ; chemistry ; Humans ; Stress, Mechanical ; Tissue Engineering ; methods ; Tissue Scaffolds ; chemistry

OBJECTIVEChromium has many important functions in the human body. For the osseous tissue, its role has not been clearly defined. This study was aimed at determining chromium content in hip joint tissues.

METHODSA total of 91 hip joint samples were taken in this study, including 66 from females and 25 from males. The sample tissues were separated according to their anatomical parts. The chromium content was determined by the AAS method. The statistical analysis was performed with U Mann-Whitney's non-parametric test, P≤0.05.

RESULTSThe overall chromium content in tissues of the hip joint in the study subjects was as follows: 5.73 µg/g in the articular cartilage, 5.33 µg/g in the cortical bone, 17.86 µg/g in the cancellous bone, 5.95 µg/g in the fragment of the cancellous bone from the intertrochanteric region, and 1.28 µg/g in the joint capsule. The chromium contents were observed in 2 group patients, it was 7.04 µg/g in people with osteoarthritis and 12.59 µg/g in people with fractures.

CONCLUSIONThe observed chromium content was highest in the cancellous bone and the lowest in the joint capsule. Chromium content was significantly different between the people with hip joint osteoarthritis and the people with femoral neck fractures.

Aged ; Bone and Bones ; chemistry ; Cartilage, Articular ; chemistry ; Chromium ; chemistry ; Environmental Exposure ; Environmental Pollutants ; chemistry ; metabolism ; Female ; Hip Joint ; chemistry ; Humans ; Male ; Middle Aged ; Smoking

This study was to explore a better three-dimensional (3-D) culture method of chondrocyte. The interpenetrating network (IPN) gel beads were developed through a photo-cross linking reaction with mixed barium ions and calcium ions at the ratio of 5:5 with the methacrylic alginate (MA), which was a chemically conjugated alginate with methacrylic groups. The second generation of primary cartilage cells was encapsulated in the MA gel beads for three weeks. In the designated timing, HE stain, Alamar blue method and Scanning electron microscopic were used to determine the cartilage cells growth, proliferation and the cell distribution in the scaffolds, respectively. The expression of type II collagen was investigated by an immunohistochemistry assay and the glycosaminoglycan content was quantitatively evaluated with the spectrophotometry of 1, 9 dimethylene blue assay. Compared to the alginate control group, the deposition of glycosaminoglycan was significantly upregulated in IPN-MA gel beads with higher cell proliferation. The secretion of extracellular matrix and proliferation of chondrocyte in methacrylic alginate gel beads were higher than that in Alginate beads. Cells were able to attach, to grow well on the scaffolds under scanning electron microscopy. The result of immunohistochemistry staining of collagen type II was positive, confirming the maintenance of chondrocyte phenotype in methacrylic alginate gel beads. This study shows a great potential for three-dimensional culture of cartilage.
Alginates ; chemistry ; Barium ; chemistry ; Calcium ; chemistry ; Cartilage ; cytology ; Cations ; Cell Culture Techniques ; instrumentation ; Cells, Cultured ; Chondrocytes ; cytology ; Collagen Type II ; chemistry ; Glucuronic Acid ; chemistry ; Glycosaminoglycans ; chemistry ; Hexuronic Acids ; chemistry ; Metals ; chemistry ; Microscopy, Electron, Scanning

OBJECTIVETo fabricate organic-inorganic composite tissue engineering scaffolds for reconstructing calcified cartilage layer based on three-dimensional (3D) printing technique.

METHODSThe scaffolds were developed by 3D-printing technique with highly bioactive calcium-magnesium silicate ultrafine particles of 1%, 3% and 5% of mass fraction, in which the organic phases were composed of type I collagen and sodium hyaluronate. The 3D-printed scaffolds were then crosslinked and solidified by alginate and CaCl₂ aerosol. The pore size and distribution of inorganic phase were observed with scanning electron microscope (SEM); the mechanical properties were tested with universal material testing machine, and the porosity of scaffolds was also measured.

RESULTSPore size was approximately (212.3 ± 34.2) μm with a porosity of (48.3 ± 5.9)%, the compressive modulus of the scaffolds was (7.2 ± 1.2) MPa, which was irrelevant to the percentage changes of calcium-magnesium silicate, the compressive modulus was between that of cartilage and subchondral bone.

CONCLUSIONThe porous scaffolds for calcified cartilage layer have been successfully fabricated, which would be used for multi-layered composite scaffolds in osteochondral injury.

Bioprinting ; Cartilage ; growth & development ; Materials Testing ; Porosity ; Printing, Three-Dimensional ; Tissue Engineering ; methods ; Tissue Scaffolds ; chemistry

BACKGROUNDDamaged articular cartilage has very limited capacity for spontaneous healing. Tissue engineering provides a new hope for functional cartilage repair. Creation of an appropriate cell carrier is one of the critical steps for successful tissue engineering. With the supposition that a biomimetic construct might promise to generate better effects, we developed a novel composite scaffold and investigated its potential for cartilage tissue engineering.

METHODSChitosan of 88% deacetylation was prepared via a modified base reaction procedure. A freeze-drying process was employed to fabricate a three-dimensional composite scaffold consisting of chitosan and type II collagen. The scaffold was treated with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide. Ultrastructure and tensile strength of the matrix were carried out to assess its physico-chemical properties. After subcutaneous implantation in rabbits, its in vivo biocompatibility and degradability of the scaffold were determined. Its capacity to sustain chondrocyte growth and biosynthesis was evaluated through cell-scaffold co-culture in vitro.

RESULTSThe fabricated composite matrix was porous and sponge-like with interconnected pores measuring from 100-250 microm in diameter. After cross-linking, the scaffold displayed enhanced tensile strength. Subcutaneous implantation results indicated the composite matrix was biocompatible and biodegradable. In intro cell-scaffold culture showed the scaffold sustained chondrocyte proliferation and differentiation, and maintained the spheric chondrocytic phenotype. As indicated by immunohistochemical staining, the chondrocytes synthesized type II collagen.

CONCLUSIONSChitosan and type II collagen can be well blended and developed into a porous 3-D biomimetic matrix. Results of physico-chemical and biological tests suggest the composite matrix satisfies the constraints specified for a tissue-engineered construct and may be used as a chondrocyte carrier for cartilage tissue engineering.

Animals ; Biodegradation, Environmental ; Cartilage ; cytology ; Chitosan ; chemistry ; Coculture Techniques ; Collagen Type II ; chemistry ; Immunohistochemistry ; Rabbits ; Tensile Strength ; Tissue Engineering ; methods

Two types(A model and B model) of articular cartilage defect models were prepared by using adult New Zealand white rabbits. A model group was applied by drilling without through subchondral bone, whose right joint was repaired by composite scaffolds made by seed cell, gum-bletilla as well as Pluronic F-127, and left side was blank control. B model group was applied by subchondral drilling method, whose right joint was repaired by using composite scaffolds made by gum-bletilla and Pluronic F-127 without seed cells, and left side was blank control. Autogenous contrast was used in both model types. In addition, another group was applied with B model type rabbits, which was repaired with artificial complex material of Pluronic F-127 in both joint sides. 4, 12 and 24 weeks after operation, the animals were sacrificed and the samples were collected from repaired area for staining with HE, typeⅡcollagen immunohistochemical method, Alcian blue, and toluidine blue, and then were observed with optical microscope. Semi-quantitative scores were graded by referring to Wakitanis histological scoring standard to investigate the histomorphology of repaired tissue. Hyaline cartilage repairing was achieved in both Group A and Group B, with satisfactory results. There were no significant differences on repairing effects for articular cartilage defects between composite scaffolds made by seed cell, gum-bletilla and Pluronic F-127, and the composite scaffolds made by gum-bletilla and Pluronic F-127 without seed cell. Better repairing effects for articular cartilage defects were observed in groups with use of gum-bletilla, indicating that gum-bletilla is a vital part in composite scaffolds material.
Animals ; Arthroplasty, Subchondral ; Cartilage, Articular ; surgery ; Cells, Cultured ; Orchidaceae ; chemistry ; Plant Gums ; chemistry ; Poloxamer ; Rabbits ; Tissue Engineering ; Tissue Scaffolds

OBJECTIVETo investigate the effect of electronspun PLGA/HAp/Zein scaffolds on the repair of cartilage defects.

METHODSThe PLGA/HAp/Zein composite scaffolds were fabricated by electrospinning method. The physiochemical properties and biocompatibility of the scaffolds were separately characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), and fourier transform infrared spectroscopy (FTIR), human umbilical cord mesenchymal stem cells (hUC-MSCs) culture and animal experiments.

RESULTSThe prepared PLGA/HAp/Zein scaffolds showed fibrous structure with homogenous distribution. hUC-MSCs could attach to and grow well on PLGA/HAp/Zein scaffolds, and there was no significant difference between cell proliferation on scaffolds and that without scaffolds (P>0.05). The PLGA/HAp/Zein scaffolds possessed excellent ability to promote in vivo cartilage formation. Moreover, there was a large amount of immature chondrocytes and matrix with cartilage lacuna on PLGA/HAp/Zein scaffolds.

CONCLUSIONThe data suggest that the PLGA/HAp/Zein scaffolds possess good biocompatibility, which are anticipated to be potentially applied in cartilage tissue engineering and reconstruction.

Animals ; Biocompatible Materials ; Bone Development ; physiology ; Cartilage ; growth & development ; Cells, Cultured ; Durapatite ; chemistry ; Female ; Humans ; Lactic Acid ; chemistry ; Male ; Mesenchymal Stromal Cells ; physiology ; Polyglycolic Acid ; chemistry ; Regeneration ; physiology ; Tissue Scaffolds ; chemistry ; Young Adult ; Zein ; chemistry

In view of the problems that conventional artificial cartilages have no bioactivity and are prone to peel off in repeated uses as a result of insufficient strength to bond with subchondral bone, we have designed and prepared a novel kind of PVA-BG composite hydrogel as bionic artificial articular cartilage/bone composite implants. The effects of processes and conditions of preparation on the mechanical properties of implant were explored. In addition, the relationships between compression strain rate, BG content, PVA hydrogels thickness and compressive tangent modulus were also explicated. We also analyzed the effects of cancellous bone aperture, BG and PVA content on the shear strength of bonding interface of artificial articular cartilage with cancellous bone. Meanwhile, the bonding interface of artificial articular cartilage and cancellous bone was characterized by scanning electron microscopy. It was revealed that the compressive modulus of composite implants was correspondingly increased with the adding of BG content and the augments of PVA hydrogel thickness. The compressive modulus and bonding interface were both related to the apertures of cancellous bone. The compressive modulus of composite implants was 1.6-2.23 MPa and the shear strength of bonding interface was 0.63-1.21 MPa. These results demonstrated that the connection between artificial articular cartilage and cancellous bone was adequately firm.
Biocompatible Materials ; chemistry ; Biomimetic Materials ; chemistry ; Bone Substitutes ; chemical synthesis ; chemistry ; Cartilage, Articular ; physiology ; surgery ; Compressive Strength ; Humans ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemistry ; Polyvinyl Alcohol ; chemistry ; Prostheses and Implants ; Prosthesis Design ; Stress, Mechanical