Research progress of the application of peptide hydrogel in the revascularization of pulp regeneration / 国际生物医学工程杂志

In recent years, problems such as the devitalization of dental pulp and the increased brittleness and fragility of teeth after root canal treatment have attracted more and more attention. Therefore, pulp regeneration has become the focus of research in endodontics and periapical disease, in which vascularization is of paramount importance. It is found that peptide hydrogel scaffolds have been widely applied because of their properties of impacting cell behavior, promoting angiogenesis, and being adaptable. In this review paper, the research progress of the application of peptide hydrogel in the vascularization of pulp regeneration and the properties of various peptide hydrogels were summarized to provide a reference for the further application of peptide hydrogel in pulp regeneration.

Applications and prospects of 3D printing technology in pulp regeneration / 口腔疾病防治

@#In recent years, pulp regeneration has become a research hotspot in the field of stomatology. 3D printing can realize precise control of structure and shape of scaffolds, which provide basis for seed cell adhesion and growth factor release. The 3D printing "pulp complexes" constructed by 3D printing scaffolds for tissue engineering provides a new direction for pulp regeneration research. This paper reviews the applications of 3D printing technology in pulp regeneration. The results of literature review showed that the scaffold materials, seed cells and growth factors in the 3D printing "pulp complexes" all play an important role in the pulp regeneration research. Among them, the scaffold materials act as carriers to load seed cells and growth factors and provide a suitable microenvironment for them. The common seed cells such as dental pulp stem cells, stem cells from apical papilla and stem cells from the human pulp of exfoliated deciduous teeth can provide the cellular basis for pulp regeneration. Moreover, the introduction of growth factors can further support the differentiation of pulp tissue and the reconstruction of pulp vessels and promote pulp regeneration. At present, the 3D printing "pulp complexes" in the study of dental pulp regeneration has made some progress and can induce the formation of pulp-like tissues in the laboratory. However, preparing 3D-printing "pulp complex" with good biological activity, which integrates biomimetic blood vessels and nerves to supply oxygen and nutrients to the cells in the root canal, remains a huge challenge and still needs further exploration and research.

Collagen as a source of bioactive peptides: a bioinformatics approach

BACKGROUND: Collagen is the most abundant protein in animals and can be obtained from residues of the food industry. Its hydrolysate has many desirable properties that make it suitable as an additive in foods and cosmetics, or as a component of scaffold materials to be used in biomedicine. RESULTS: We report here the characterization of type I collagen from five different sources, namely bovine, porcine, chicken, trout and salmon, as well as their hydrolysates by means of bioinformatics tools. As expected, the results showed that bovine and porcine collagen, as well as trout and salmon collagen, can be used interchangeably due to their high identity. This result is consistent with the evolution of proteins with highly identical sequences between related species. Also, 156 sequences were found as potential bioactive peptides, 126 from propeptide region and 30 from the central domain, according to the comparison with reported active sequences. CONCLUSIONS: Collagen analysis from a bioinformatic approach allowed us to classify collagen from 5 different animal sources, to establish its interchangeability as potential additive in diverse fields and also to determine the content of bioactive peptides from its in silico hydrolysis.

Research progress in osteogenic differentiation of adipose-derived stem cells induced by bioscaffold materials / 中国组织工程研究

BACKGROUND: Adipose-derived stem cells are easy to access and have strong proliferative capacity, which are considered as ideal seed cells for bone defect repair. The bone tissue engineering research progress reveals that bioscaffold material modification can directly regulate the osteogenic differentiation of stem cells. OBJECTIVE: To review various biological scaffold materials that can regulate the osteogenic differentiation of adipose-derived stem cells. METHODS: The first author searched the articles in CNKI, WanFang, VIP, PubMed, Embase and Web of Science databases published from January 2016 to May 2019. The search terms were “adipose derived stem cells, scaffold, osteogenic, metal, Ti” in Chinese and English, respectively. Finally 62 eligible articles were selected. RESULTS AND CONCLUSION: Scaffold materials for bone tissue engineering are classified into inorganic materials (hydroxyapatite, tricalcium phosphate, bioglass, titanium, and magnesium), natural polymer materials (collagen, silk fibroin, and chitosan) and synthetic polymer materials (polycaprolactone, polylactic acid, polyglycolic acid and poly(lactic-co-glycolic acid)). The studies on materials that interact with cells to guide their biological response and bone differentiation are increasing. But how to create a safe, rational, and close to the micro-environment of cell growth in vivo is a challenge. Modification of bioscaffold materials can directly regulate osteogenic differentiation of stem cells. Moreover, vascularization and post-implantation infections are issues of concern.

Biological evaluation of scaffold materials for external skeletal fixation / 医疗卫生装备

Objective To provide integral biological assessment on carbon fiber,aluminum alloy (6061)and stainless steel (05Cr17Ni4Cu4Nb)for external skeletal fixation.Methods According to biological evaluation criterion of medical devices, four tests in vitro and vivo were selected on the basis of the GB/T 14233.2—2005 and GB/T 16886 serial standards. The cytotoxicity test determined with MTT method. Acute general toxicity test, tests for irritation and delayed -type hypersensitivity were to evaluate biological safety by two leaching media of polar solvent (sodium chloride) and nonpolar solvent (cottonseed oil).Results The scaffold materials of external skeletal fixation had no cell toxicity in vitro.The three materials had none of acute general toxicity, skin irritation and sensitization in sodium chloride and cottonseed oil. Conclusion Carbon fiber,aluminum alloy (6061)and stainless steel (05Cr17Ni4Cu4Nb)are kinds of bone external scaffold materials with high biocompatibility and can be safely applied for clinical use.

Research progress of injectable bone tissue engineering scaffold material / 国际生物医学工程杂志

Injectable bone tissue engineering scaffold material has a certain form and mechanical strength.It can be loaded with seed cells for injection to the defected site of bone tissue in the form of fluid.After that,structural recovery and functional reconstruction are achieved,and the new bone is formed ultimately.This material has the characteristics of small trauma and good plasticity.It can repair the irregular bone defects and well associate with growth factor,which is the ideal method for repairing bone tissue defects up to now.Among the various injectable bone tissue engineering materials,bioceramic materials,polymer materials,etc.have been proved to have a high biological compatibility and good mechanical properties.That makes these materials become the focus of current research in bone tissue engineering materials.In this paper,the development and application of bioceramic materials,polymer materials,bioceramics and polymer composites were reviewed.

Comparison of the biocompatibility of three kinds of antigen-extracted xenogeneic cancellous bone matrices / 中国组织工程研究

BACKGROUND:The form and structure of antigen-extracted xenogeneic cancel ous bone through series of physical and chemical treatment are similar to human tissue. OBJECTIVE:To detect the biocompatibility of antigen-extracted xenogeneic cancel ous bone matrix prepared by three different ways. METHODS:The antigen-extracted xenogeneic cancel ous bone scaffold materials which were prepared through physical, chemical and physical-chemical combined methods and hydroxy apatite biological ceramic materials were implanted into the dorsum subcutaneous tissue. Histological observation was done at 4, 8 and 12 weeks after surgery. The antigen-extracted xenogeneic cancel ous bone scaffold materials which were prepared through physical, chemical and physical-chemical combined methods respectively was used to culture sheep bone marrow mesenchymal stem cells for 7 days. Cel adhesion, growth, proliferation and stroma secretion were observed. RESULTS AND CONCLUSION:At 4 weeks after surgery, a strong inflammatory reaction was detected around materials in four groups. At 12 weeks, the xenogeneic bone materials prepared through physical and physical-chemical combined methods and hydroxy apatite biological ceramic materials internal pore and surrounding tissue inflammation disappeared basical y, with the presence of thimbleful inflammation cells. The material degradation was more than at 8 weeks. The xenogeneic bone materials prepared through chemical methods material internal pore and surrounding tissue inflammation stil existed, suggesting that the xenogeneic bone materials prepared through physical and physical-chemical combined methods exhibited good histocompatibility. A smal amount of orderly osteoblasts existed around hydroxy apatite biological ceramic materials and physical-chemical prepared materials, with a smal amount of bone. These suggested that there was a tendency for ectopic bone formation. The xenogeneic cancel ous bone materials prepared through physical or physical-chemical combined methods have better cytocompatibility. However, scaffold materials prepared through chemical method have poor cytocompatibility and they are not qualified for the safety standards of biological materials.

Combination of cryopreserved hydroxyapatite/bone marrow mesenchymal stem cells repairs rabbit radial defects / 中国组织工程研究

10.3969/j.issn.2095-4344.2013.25.010

Histopathological observation of new soft one-piece keratoprosthesis skirt implanted into alkali burned rabbit corneas / 中国组织工程研究

BACKGROUND:Polyhydroxyethyl methacrylate has excel ent optical properties and good hydrophilicity which has been widely applied in biological materials, such as contact lenses, intraocular lenses. In previous experiments, artificial corneas made of polyhydroxyethyl methacrylate subcutaneously implanted or implanted into normal rabbit cornea have showed good biocompatibility and tear resistance. OBJECTIVE:To evaluate the histopathological results of the porous skirt of new type one-piece keratoprosthesis made of polyhydroxyethyl methacrylate implanted to alkali burned rabbit corneas. METHODS:New blood vessels and wal eyes formed in New Zealand rabbits at 3 months after alkali burned rabbit corneas. The porous discs of polyhydroxyethyl methacrylate were inserted into the lamel ar pocket of alkali-burned corneas and the corneas were observed clinical y, histological y and ultrastructural y at 2, 8, 16 and 28 weeks after implantation,. RESULTS AND CONCLUSION: Histopathology suggested that mild inflammatory reaction and no calcification were seen in al specimens, fibroblasts and deposition of col agens were found in the pores of the dics at 2 weeks after implantation;stable connection with cornea was formed by the end of 16 weeks;the pores were almost completely fil ed with new tissue, the number of cel s decreased, and mature fibers were mainly found at 28 weeks. Scanning electron microscope showed new tissue grew into the pores which were closely connected with the corneas. Transmission electron microscope exhibited cytoplasm migrating into the material was rich in rough endoplasmic reticula, showing strong synthetic function, col agen, proteoglycans, and other extracel ular matrix deposition. These findings indicate that the porous skirt of polyhydroxyethyl methacrylate implanted into the alkali burned rabbit corneas al owed corneal cel s migration, proliferation, secretion of the deposition of extracel ular matrix and the formation of new tissue to complete the stable connection with cornea, showing a better biocompatibility.

Cellular affinity of inorganic active element bone scaffold materials / 中华医学美学美容杂志

Objective To study the cellular affinity of the inorganic active element bone scaffold materials. Methods The specific surface area, pore size distribution, porous ratio, permeability ratio of the inorganic active element bone scaffold materials were evaluated in vitro. Human marrow mesenchymal stem cells(MSCs) were cultured and identified by the flow cytometry, the third passage of the cells were used to culture with scaffold materials, to compare with the cells cultured with pure fetal calf serum as the control group. MTT assay was used to examine the effects of scaffold materials on MSCs viability, the growth of cells was observed by scanning electron microscope (SEM). Results The specific surface area of the inorganic active element bone scaffold materials was 210 m2/g, mean pore size was 6 nm, porous ratio was 90 %, and permeability ratio was34 %. MTT assay showed significant difference in the number of cells between the scaffold materials and the control group (P ＜ 0.05 ) on the seventh day, MSCs co-cultured with scaffold materials exhibited good growth as observed under SEM. Conclusion The inorganic active element bone scaffold materials possess preferable cellular affinity, which could be an overall-developed and high potential scaffold material of bone tissue engineering.

Advances in the research of urethral tissue engineering and scaffold materials / 国际生物医学工程杂志

Urethral reconstruction is required in congenital abnormalities such as hypospadia and urethral stricture caused by trauma or infection. The development of tissue engineering has brought new hope to the field of urethral reconstruction. Much progress has been made in the experimental and clinical research of using tissue engineering for urethral reconstruction as well as the research of the scaffold materials. This review focuses on the recent progress in this field.

Scaffold materials in tissue engineering of tendon and ligament / 国际外科学杂志

Terapeutic options used to repair tendon and ligament injury consist of autografis,allografts and synthetic prostheses.Tendon and ligament of tissue engineering have their unique advantages as alternative therapy.Choosing the proper scaffold materials is important for successfully constructing tissue engineering tendon and ligament,so in this review we focus on natural and artificial scaffold materials used in tissue engineering of tendon and ligament in recent years.

Ethical Anglysis for Tissue Engineering / 中国医学伦理学

Objective To explore the medical ethical problens in the research of tissue engineering and their clinical application.Methods According to the technical route of tissue engineering ,including seeding cells.scaffold materials,implantation in body,ethical problems and their disposal were dissussed.Results Patient's rights to know the facts of test,efficacy and security of clinical application must be fully ensured during implantation of seeding cells and scaffold materials to human body.Conclusion In needs to formulate related standard of tissue engineered products and perfect politics and regulations.

The Comparison of Characteristics of Scaffold Materials in Bone Tissue Engineering / 昆明医科大学学报

The research in bone tissue engineering is abundant and its development is rapid,however,there has been no ideal scaffold materials.We review the recent articles on bone tissue engineering,including ceramics materials,polymerized materials,materials deriver from natural biological organism and their compound materials