OBJECTIVE: To review the research progress of strontium (Sr) modified β-tricalcium phosphate composite biomaterials (SrTCP) promoting osteogenesis through immune regulation, and provides reference and theoretical support for the further development and research of SrTCP bone repair materials in bone tissue engineering in the future. METHODS: The literature about SrTCP promoting osteogenesis through immune regulation at home and abroad in recent years was extensively reviewed, and the preparation methods, immune mechanism and application of promoting osteogenesis were summarized and analyzed. RESULTS: The preparation methods of SrTCP include solid-state reaction sintering method, solution combustion quenching method, direct doping method, ion substitution method, etc. SrTCP has immune regulatory effects, which can play an immune regulatory role in inducing macrophage polarization, inducing angiogenesis and anti oxidative stress to promote osteogenesis. CONCLUSION At present, studies have shown that SrTCP can promote bone defect repair through immune regulation. Subsequent studies can start from the control of the optimal repair concentration and release rate of Sr, and further clarify the specific mechanism of SrTCP in promoting angiogenesis and anti oxidative stress, which is helpful to develop new materials for bone defect repair.
Calcium Phosphates/pharmacology* ; Strontium/pharmacology* ; Biocompatible Materials/pharmacology* ; Humans ; Osteogenesis/drug effects* ; Tissue Engineering/methods* ; Bone Substitutes/pharmacology* ; Bone Regeneration/drug effects* ; Animals ; Tissue Scaffolds/chemistry* ; Neovascularization, Physiologic/drug effects* ; Macrophages/immunology*

Schwann cells and macrophages are the main immune cells involved in peripheral nerve injury. After injury, Schwann cells produce an inflammatory response and secrete various chemokines, inflammatory factors, and some other cytokines to promote the recruitment and M2 polarization of blood-derived macrophages, enhancing their phagocytotic ability, and thus play an important role in promoting nerve regeneration. Macrophages have also been found to promote vascular regeneration after injury, promote the migration and proliferation of Schwann cells along blood vessels, and facilitate myelination and axon regeneration. Therefore, there is a close interaction between Schwann cells and macrophages during peripheral nerve regeneration, but this has not been systematically summarized. In this review, the mechanisms of action of Schwann cells and macrophages in each other's migration and phenotypic transformation are reviewed from the perspective of each other, to provide directions for research on accelerating nerve injury repair.
Schwann Cells/metabolism* ; Peripheral Nerve Injuries/physiopathology* ; Animals ; Macrophages/immunology* ; Nerve Regeneration/physiology* ; Humans ; Cell Movement/physiology*

Ambystoma mexicanum/immunology* ; Amputation ; Animals ; Biomarkers/metabolism* ; Blastomeres/immunology* ; Cell Lineage/immunology* ; Connective Tissue Cells/immunology* ; Epithelial Cells/immunology* ; Forelimb ; Gene Expression ; High-Throughput Nucleotide Sequencing ; Humans ; Immunity ; Peroxiredoxins/immunology* ; Regeneration/immunology* ; Regenerative Medicine/methods* ; Single-Cell Analysis/methods*

γδ T cells display unique developmental, distributional, and functional patterns and can rapidly respond to various insults and contribute to diverse diseases. Different subtypes of γδ T cells are produced in the thymus prior to their migration to peripheral tissues. γδ T cells are enriched in the liver and exhibit liver-specific features. Accumulating evidence reveals that γδ T cells play important roles in liver infection, non-alcoholic fatty liver disease, autoimmune hepatitis, liver fibrosis and cirrhosis, and liver cancer and regeneration. In this study, we review the properties of hepatic γδ T cells and summarize the roles of γδ T cells in liver diseases. We believe that determining the properties and functions of γδ T cells in liver diseases enhances our understanding of the pathogenesis of liver diseases and is useful for the design of novel γδ T cell-based therapeutic regimens for liver diseases.
Animals ; Cytokines ; immunology ; Humans ; Liver Diseases ; immunology ; Liver Regeneration ; immunology ; Mice ; T-Lymphocytes, Regulatory ; immunology

Currently, the most effective treatment for end-stage liver fibrosis is liver transplantation; however, transplantation is limited by a shortage of donor organs, surgical complications, immunological rejection, and high medical costs. Recently, mesenchymal stem cell (MSC) therapy has been suggested as an effective alternate approach for the treatment of hepatic diseases. MSCs have the potential to differentiate into hepatocytes, and therapeutic value exists in their immune-modulatory properties and secretion of trophic factors, such as growth factors and cytokines. In addition, MSCs can suppress inflammatory responses, reduce hepatocyte apoptosis, increase hepatocyte regeneration, regress liver fibrosis and enhance liver functionality. Despite these advantages, issues remain; MSCs also have fibrogenic potential and the capacity to promote tumor cell growth and oncogenicity. This paper summarizes the properties of MSCs for regenerative medicine and their therapeutic mechanisms and clinical application in the treatment of liver fibrosis. We also present several outstanding risks, including their fibrogenic potential and their capacity to promote pre-existing tumor cell growth and oncogenicity.
Animals ; Cell Differentiation ; Cell Proliferation ; Hepatocytes/immunology/metabolism/pathology/*transplantation ; Humans ; Liver/immunology/metabolism/pathology/physiopathology/*surgery ; Liver Cirrhosis/diagnosis/immunology/metabolism/physiopathology/*surgery ; Liver Regeneration ; *Mesenchymal Stem Cell Transplantation/adverse effects ; *Mesenchymal Stromal Cells/immunology/metabolism/pathology ; Phenotype ; Regenerative Medicine/*methods ; Risk Factors ; Signal Transduction ; Treatment Outcome

There have been many attempts for regeneration of peripheral nerve injury. In this study, we examined the in vivo effects of non-differentiated and neuronal differentiated adipose-derived stem cells (ADSCs) in inducing the neuronal regeneration in the Sprague-Dawley (SD) rats undergoing nerve defect bridged with the PCL nanotubes. Then, we performed immunohistochemical and histopathologic examinations, as well as the electromyography, in three groups: the control group (14 sciatic nerves transplanted with the PCL nanotube scaffold), the experimental group I (14 sciatic nerves with the non-differentiated ADSCs at a density of 7x105 cells/0.1 mL) and the experimental group II (14 sciatic nerves with the neuronal differentiated ADSCs at 7x105 cells/0.1 mL). Six weeks postoperatively, the degree of the neuronal induction and that of immunoreactivity to nestin, MAP-2 and GFAP was significantly higher in the experimental group I and II as compared with the control group. In addition, the nerve conduction velocity (NCV) was significantly higher in the experimental group I and II as compared with the control group (P=0.021 and P=0.020, respectively). On the other hand, there was no significant difference in the NCV between the two experimental groups (P>0.05). Thus, our results will contribute to treating patients with peripheral nerve defects using PCL nanotubes with ADSCs.
Adipose Tissue/cytology ; Animals ; Cell Differentiation ; Electromyography ; Male ; Nanotubes ; *Nerve Regeneration ; Nerve Tissue Proteins/immunology ; Nestin/immunology ; Neural Conduction/physiology ; Peripheral Nerve Injuries/*surgery ; Phosphoprotein Phosphatases/immunology ; Polyesters/*therapeutic use ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve/injuries/surgery ; Stem Cell Transplantation/*methods ; Stem Cells/*cytology ; Tissue Engineering/methods

Mesenchymal stem cells (MSCs) are self-renewing, multipotent progenitor cells with multilineage potential to differentiate into cell types of mesodermal origin, such as adipocytes, osteocytes, and chondrocytes. In addition, MSCs can migrate to sites of inflammation and exert potent immunosuppressive and anti-inflammatory effects through interactions between lymphocytes associated with both the innate and adaptive immune system. Along with these unique therapeutic properties, their ease of accessibility and expansion suggest that use of MSCs may be a useful therapeutic approach for various disorders. In the clinical setting, MSCs are being explored in trials of various conditions, including orthopedic injuries, graft versus host disease following bone marrow transplantation, cardiovascular diseases, autoimmune diseases, and liver diseases. Furthermore, genetic modification of MSCs to overexpress antitumor genes has provided prospects for clinical use as anticancer therapy. Here, we highlight the currently reported uses of MSCs in clinical trials and discuss their efficacy as well as their limitations.
Animals ; Cell Differentiation ; Cell Lineage ; Cell Movement ; Cell Proliferation ; Gene Expression Regulation ; Humans ; *Mesenchymal Stem Cell Transplantation/adverse effects ; Mesenchymal Stromal Cells/immunology/*physiology ; *Regeneration ; Regenerative Medicine/*methods ; Treatment Outcome

OBJECTIVETo observe the change in quantity and morphology of nerve fibers in different periods in granulation tissue in full-thickness burn wound.

METHODSThe granulation tissue samples were harvested from 40 patients with full-thickness burn in our unit at 1st, 2nd, 3rd and 4th post burn week (PBW), 10 samples were obtained at each time point. Donor site tissues from 10 burn patients were used as normal control. Immunofluorescent staining technique with anti-neurofilament (NF) monoclonal antibody was employed to examine the expression of nerve fibers in granulation tissue and normal skin. The morphology of nerve fibers was observed with fluorescence microscope and laser scanning confocal microscope.

RESULTSFluorescence microscopy showed: nerve fibers were short and rare at 1 PBW, the ratio of nerve fibers positive area was (0.14 +/- 0.08)%. Nerve fibers increased slightly and were in single filament without branches, and the positive area ratio of nerve fibers (0.40 +/- 0.09)% was much lower than that of normal control [(0.62 +/- 0.12)%, P < 0.05]. Nerve fibers increased significantly and were arranged like a mesh with more branches and sproutings, and the positive area ratio of nerve fibers was (0.73 +/- 0.16)% at 3 PBW. The quantity of nerve fibers at 4 PBW was similar to that of 3 PBW, and the positive area ratio of nerve fibers was (0.66 +/- 0.13)%. Observations under LSCM: the nerve fibers were short at 1, 2 PBW; was irregular at 3 PBW, among them some were swollen and distorted, and fragmentation and vacuolation were observed. They became aggregated at 4PBW with less branches, similar to that at 3 PBW. The structures of nerve fibers in normal control were intact, without obvious pathological changes.

CONCLUSIONThe change in quantity and morphology of nerve fibers in burn wound is related to the time of granulation tissue development.

Adult ; Burns ; pathology ; Female ; Fluorescent Antibody Technique ; Granuloma ; etiology ; pathology ; Humans ; Male ; Middle Aged ; Nerve Fibers ; metabolism ; pathology ; Nerve Regeneration ; Neurofilament Proteins ; immunology ; Skin ; innervation ; Wound Healing

OBJECTIVE: To examine the biocompatibility of polylactic/glycolic acid (PLGA) and Schwann cells. METHOD: Schwann cells were harvested from rat brachial and sciatic nerves. Schwann cells were cultured with PLGA, observed by phase-contrast microscopy and electron microscopy. RESULT: Schwann cells could attach and proliferate on the surface of the PLGA. CONCLUSION The PLGA has good cellular biocompatibility. It can be used as biomaterial for tissue engineering.
Animals ; Biocompatible Materials ; Cells, Cultured ; Lactic Acid ; Nerve Regeneration ; Polyesters ; Polyglycolic Acid ; Polymers ; Rats ; Rats, Sprague-Dawley ; Schwann Cells ; cytology ; immunology

Biomedical Research ; trends ; Computers ; Humans ; Implants, Experimental ; Myelin Proteins ; antagonists & inhibitors ; immunology ; Nerve Regeneration ; immunology ; physiology ; Nogo Proteins ; Patient Education as Topic ; Spinal Cord Injuries ; therapy