In maxillofacial surgery, there is a significant need for the design and fabrication of porous scaffolds with customizable bionic structures and mechanical properties suitable for bone tissue engineering. In this paper, we characterize the porous Ti6Al4V implant, which is one of the most promising and attractive biomedical applications due to the similarity of its modulus to human bones. We describe the mechanical properties of this implant, which we suggest is capable of providing important biological functions for bone tissue regeneration. We characterize a novel bionic design and fabrication process for porous implants. A design concept of "reducing dimensions and designing layer by layer" was used to construct layered slice and rod-connected mesh structure (LSRCMS) implants. Porous LSRCMS implants with different parameters and porosities were fabricated by selective laser melting (SLM). Printed samples were evaluated by microstructure characterization, specific mechanical properties were analyzed by mechanical tests, and finite element analysis was used to digitally calculate the stress characteristics of the LSRCMS under loading forces. Our results show that the samples fabricated by SLM had good structure printing quality with reasonable pore sizes. The porosity, pore size, and strut thickness of manufactured samples ranged from (60.95± 0.27)% to (81.23±0.32)%, (480±28) to (685±31) μm, and (263±28) to (265±28) μm, respectively. The compression results show that the Young's modulus and the yield strength ranged from (2.23±0.03) to (6.36±0.06) GPa and (21.36±0.42) to (122.85±3.85) MPa, respectively. We also show that the Young's modulus and yield strength of the LSRCMS samples can be predicted by the Gibson-Ashby model. Further, we prove the structural stability of our novel design by finite element analysis. Our results illustrate that our novel SLM-fabricated porous Ti6Al4V scaffolds based on an LSRCMS are a promising material for bone implants, and are potentially applicable to the field of bone defect repair.
Alloys ; Bionics ; Bone Substitutes/chemistry* ; Bone and Bones/pathology* ; Compressive Strength ; Elastic Modulus ; Finite Element Analysis ; Humans ; Lasers ; Materials Testing ; Maxillofacial Prosthesis Implantation ; Porosity ; Pressure ; Printing, Three-Dimensional ; Prostheses and Implants ; Prosthesis Design ; Stress, Mechanical ; Surgery, Oral/instrumentation* ; Tissue Engineering/methods* ; Titanium/chemistry*

The ideal treatment and recovery of osteoarticular injury remain to be resolved. Small intestinal submucosa (SIS), a naturally-occurring decellularized extracellular matrix, has been recognized as an ideal scaffold for tissue engineering and widely used in repairing various tissues and organs. Nowadays its application has also been gradually increased in the field of orthopedics. We reviewed laboratorial studies and clinical trails about the application of SIS in bone and joint repair, aiming to evaluate its effects on the repair of bone, cartilage, meniscus, ligament and tendon. SIS has showed promising results in repairing bone, meniscus, ligament or tendon. However, additional studies will be required to further evaluate its effects on articular cartilage and tendon-bone healing. How to optimize SIS material,is also a focused problem concerned with making SIS a potential therapeutic option with high value for orthopedic tissue repair.
Animals ; Cell- and Tissue-Based Therapy ; Humans ; Intestinal Mucosa ; cytology ; Intestine, Small ; cytology ; Joint Diseases ; physiopathology ; surgery ; therapy ; Tissue Engineering ; instrumentation ; methods ; Tissue Scaffolds ; chemistry

To evaluate the effect of laser solid forming (LSF) of porous titanium on receptor activator of NF-κB ligand (RANKL)/osteoprorotegerin (OPG) expression and osteoblast cells growth.
 Methods: The DMEM and sterile saline were used for porous titanium extract. The osteoblast cells were cultured in the extract while equal amount of  DMEM and sterile saline were added to the control group. The growth of the cells were observed under an inverted phase contrast microscope. MTT was used to detect the growth inhibitory rates. The adhesion capacity of osteoblasts were measured. The growth in the material surface was examined by the electron microscope, and the expressions of RANKL and OPG were determined by Westen blot.
 Results: At the first day, the osteoblast proliferation rate was significantly different (P<0.05), at the fourth and seventh day, the osteoblast proliferation rate was not significantly affected in the LSF group (P>0.05); at each time point, the osteoblast proliferation rate were significantly different between the two groups (P<0.05). Compared with the control group, RANKL and OPG protein expression were not significantly different (P>0.05). The laser solid forming of porous titanium showed well bone compatibility.
 Conclusion: The porous titanium did not affect osteoblast proliferation due to its well bone compatibility. It did not affect the OPG/RANKL/RANK-axis system of bone metabolism, exibiting a wide applicable prospect for tissue engineering.
Biocompatible Materials ; chemistry ; Cell Adhesion ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Culture Media ; chemistry ; Ligands ; Osteoblasts ; drug effects ; Osteogenesis ; drug effects ; Osteoprotegerin ; metabolism ; Porosity ; Receptor Activator of Nuclear Factor-kappa B ; metabolism ; Tissue Engineering ; instrumentation ; Tissue Scaffolds ; chemistry ; Titanium ; pharmacology

OBJECTIVETo evaluate the influence of adipose tissue extract on inducing angiogenesis and adipogenesis in adipose tissue engineering chamber in vivo.

METHODS6 months' healthy New Zealand rabbits (n = 64) were picked. The inguinal fat pads were cultured, centrifuged, filtered, and the liquid was called adipose tissue extract (ATE). Two adipose tissue engineering chamber were built in the rabbit's back. A week later, 0.2 ml normal saline (control group, left) and 0. 2 ml ATE (experimental group, right) was respectively injected into the chamber. The contents were evaluated morphometrically, histologically and immunohistochemically 3 days, 1 week, 2 weeks, 3 weeks, 4 weeks and 7 weeks after injection. 8 rabbits were observed each time. The data regarding the number of the volume of fat flap and blood capillary at each time point were analyzed by paired t test.

RESULTSAfter injection, new tissue volume was significantly increased in the experimental group [(5.12 ± 0.22) ml], compared with that in control group [(4.90 ± 0.15) ml]. Early angiogenesis was also increased after ATE injection and the total number of capillaries reached peak 1 week after injection, which was (72.80 ± 9.67) in experimental group and (51.40 ± 6.09) in control group. In the mid-term of experimental period, earlier adipogenesis appeared in experimental group. In the later period, the outer capsule of the new construction was thinner in experimental group which reduced the suppression of the adipogenesis.

CONCLUSIONSATE can promote the angiogenesis and adipogenesis in the chamber, and reduce the capsule contracturing, so as to induce the large volume of adipose tissue regeneration

Adipogenesis ; drug effects ; physiology ; Adipose Tissue ; chemistry ; physiology ; Animals ; Neovascularization, Physiologic ; drug effects ; Rabbits ; Regeneration ; Tissue Engineering ; instrumentation ; Tissue Extracts ; pharmacology

Tissue engineering technology provides a new method to repair ill tissue and worn-out organs. In tissue engineering, scaffolds play an important role in supporting cell growth, inducing tissue regeneration, controlling tissue structure and releasing active factor. In the last decade, electrospinning technology developed rapidly and opened vast application fields for scaffolds. In this review, we summarized the technological conditions of electrospinning for scaffolds, the study of electrospun fiber scaffolds applied in tissue cell cultivation, and some new directions of electrospinning technology for scaffolds. We also addressed development directions of electrospinning research for scaffolds.
Absorbable Implants ; Biocompatible Materials ; chemistry ; Electrochemistry ; methods ; Guided Tissue Regeneration ; Tissue Engineering ; instrumentation ; methods ; Tissue Scaffolds ; chemistry

Increasing incidence of musculoskeletal injuries coupled with limitations in the current treatment options have necessitated tissue engineering and regenerative medicine- based approaches. Moving forward from engineering isolated musculoskeletal tissues, research strategies are now being increasingly focused on repairing and regenerating the interfaces between dissimilar musculoskeletal tissues with the aim to achieve seamless integration of engineered musculoskeletal tissues. This article reviews the state-of-the-art in the tissue engineering of musculoskeletal tissue interfaces with a focus on Singapore's contribution in this emerging field. Various biomimetic scaffold and cellbased strategies, the use of growth factors, gene therapy and mechanical loading, as well as animal models for functional validation of the tissue engineering strategies are discussed.
Cell- and Tissue-Based Therapy ; Genetic Therapy ; Humans ; Intercellular Signaling Peptides and Proteins ; Musculoskeletal Diseases ; rehabilitation ; therapy ; Orthopedic Procedures ; instrumentation ; methods ; Osteogenesis ; Regenerative Medicine ; instrumentation ; methods ; Singapore ; Stem Cells ; Stress, Mechanical ; Tissue Engineering ; instrumentation ; methods ; Tissue Scaffolds ; Weight-Bearing

Nanostructured materials are gaining new impetus owing to the advancements in material fabrication techniques and their unique properties (their nanosize, high surface area-to-volume ratio, and high porosity). Such nanostructured materials mimic the subtleties of extracellular matrix (ECM) proteins, creating artifi cial microenvironments which resemble the native niches in the body. On the other hand, the isolation of mesenchymal stem cells (MSCs) from various tissue sources has resulted in the interest to study the multiple differentiation lineages for various therapeutic treatments. In this review, our focus is tailored towards the potential of biomimetic nanostructured materials as osteoinductive scaffolds for bone regeneration to differentiate MSCs towards osteoblastic cell types without the presence of soluble factors. In addition to mimicking the nanostructure of native bone, the supplement of collagen and hydroxyapatite which mimic the main components of the ECM also brings signifi cant advantages to these materials.
Biomimetics ; instrumentation ; methods ; Bone Transplantation ; Collagen Type I ; Extracellular Matrix ; Humans ; Mesenchymal Stromal Cells ; Nanostructures ; Osteogenesis ; Tissue Engineering ; instrumentation ; methods

Three-dimensionally controlled cell-assembly technique makes fabricating tissues and organs in vitro to be possible. However, for real tissues and organs with complex structure and various cells, fabricating tissues and organs in vitro need a technique that could assemble and locate multi cells and materials precisely in the space. Facing the needs of multi-cell assembly, we designed a mixer nozzle and the matching pulse switching circuit which based on the single-nozzle cell assembly system, and developed a multi-cell-assembly system. We also carried out some assembly experiments with this system using materials that were similar to the multi-component extracellular matrix materials. The results demonstrated that the system could assemble various cells and materials into three-dimensional inhomogeneous structures precisely.
Bioartificial Organs ; Cell Culture Techniques ; instrumentation ; Cell Physiological Phenomena ; Equipment Design ; methods ; Extracellular Matrix ; chemistry ; Humans ; Tissue Engineering ; methods

OBJECTIVETo compare macroporous microcarrier Cytopore 2 and Cultispher S for their effects in microgravity culture of CL-1 cells.

METHODSCL-1 cells were cultured on Cytopore 2 and Cultispher S respectively in a rotational cell culture system (RCCS) in a volume of 50 ml. Dynamic morphological observation and cell counting and functional test were carried out during the cell culture.

RESULTSThe cells were capable of adhering to and proliferating on both of the microcarriers, reaching the growth peak on day 9 of cell culture with the maximum cell density of 4x10(6)/ml on cultispher S. Albumin was significantly higher in the supernatant of Cytopore 2 than in that of Cultispher S on days 10, 11, and 12 (P<0.05), and the urea level in the supernatant of cytopore 2 was also significantly higher on days 10 and 11 (P<0.05).

CONCLUSIONThe cells cultured on Cytopore 2, though with a smaller cell number, display better functions than those cultured on Cultispher S under RCCS conditions.

Cell Culture Techniques ; instrumentation ; methods ; Cell Division ; physiology ; Cell Line ; Cellulose ; Gelatin ; Hepatocytes ; cytology ; Humans ; Liver, Artificial ; Porosity ; Tissue Engineering ; methods ; Tissue Scaffolds ; Weightlessness

Electrospinning is a very effective way to prepare scaffolds for biomedical applications. However, conventional electrospinning technique has shortcomings for this purpose. Modification studies on electrospinning technique have been conducted by more and more researchers. This paper summaries the research progress in electrospinning technique for biomedical materials.
Biocompatible Materials ; chemical synthesis ; Elasticity ; Electrochemistry ; instrumentation ; methods ; Materials Testing ; Nanostructures ; chemistry ; Tissue Engineering ; methods ; Tissue Scaffolds ; chemistry