A cervical cancer tissue-derived decellularized extracellular matrix scaffold for cervical cancer tissue reconstruction in vitro / 南方医科大学学报

OBJECTIVE@#The prepare decellularized extracellular matrix (ECM) scaffold materials derived from human cervical carcinoma tissues for 3D culture of cervical carcinoma cells.@*METHODS@#Fresh human cervical carcinoma tissues were treated with sodium lauryl ether sulfate (SLES) solution to prepare decellularized ECM scaffolds. The scaffolds were examined for ECM microstructure and residual contents of key ECM components (collagen, glycosaminoglycan, and elastin) and genetic materials by pathological staining and biochemical content analysis. In vitro 3D culture models were established by injecting cultured cervical cancer cells into the prepared ECM scaffolds. The cells in the recellularized scaffolds were compared with those in a conventional 2D culture system for cell behaviors including migration, proliferation and epithelial-mesenchymal transition (EMT) wsing HE staining, immunohistochemical staining and molecular biological technology analysis. Resistance to 5-fluorouracil (5-Fu) of the cells in the two culture systems was tested by analyzing the cell apoptosis rates via flow cytometry.@*RESULTS@#SLES treatment effectively removed cells and genetic materials from human cervical carcinoma tissues but well preserved the microenvironment structure and biological activity of ECM. Compared with the 2D culture system, the 3D culture models significantly promoted proliferation, migration, EMT and 5-Fu resistance of human cervical cancer cells.@*CONCLUSION@#The decellularized ECM scaffolds prepared using human cervical carcinoma tissues provide the basis for construction of in vitro 3D culture models for human cervical cancer cells.

Applicatoin of chitosan-based hydrogel in oral tissue engineering / 中南大学学报(医学版)

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.

Culture of rat mesenchymal stem cells on PHBV-PCL scaffolds: analysis of conditioned culture medium by FT-Raman spectroscopy / Cultivo de células-tronco mesenquimais de rato sobre arcabouços de PHBV-PCL: análise do meio de cultura condicionado por espectroscopia de FT-Raman

Abstract Mesenchymal stem cells (MSCs) have great potential for application in cell therapy and tissue engineering procedures because of their plasticity and capacity to differentiate into different cell types. Given the widespread use of MSCs, it is necessary to better understand some properties related to osteogenic differentiation, particularly those linked to biomaterials used in tissue engineering. The aim of this study was to develop an analysis method using FT-Raman spectroscopy for the identification and quantification of biochemical components present in conditioned culture media derived from MSCs with or without induction of osteogenic differentiation. All experiments were performed between passages 3 and 5. For this analysis, MSCs were cultured on scaffolds composed of bioresorbable poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(ε-caprolactone) (PCL) polymers. MSCs (GIBCO®) were inoculated onto the pure polymers and 75:25 PHBV/PCL blend (dense and porous samples). The plate itself was used as control. The cells were maintained in DMEM (with low glucose) containing GlutaMAX® and 10% FBS at 37oC with 5% CO2 for 21 days. The conditioned culture media were collected and analyzed to probe for functional groups, as well as possible molecular variations associated with cell differentiation and metabolism. The method permitted to identify functional groups of specific molecules in the conditioned medium such as cholesterol, phosphatidylinositol, triglycerides, beta-subunit polypeptides, amide regions and hydrogen bonds of proteins, in addition to DNA expression. In the present study, FT-Raman spectroscopy exhibited limited resolution since different molecules can express similar or even the same stretching vibrations, a fact that makes analysis difficult. There were no variations in the readings between the samples studied. In conclusion, FT-Raman spectroscopy did not meet expectations under the conditions studied.

Resumo As células-tronco mesenquimais (MSCs) possuem grande potencial para aplicação em procedimentos terapêuticos ligados a terapia celular e engenharia de tecidos, considerando-se a plasticidade e capacidade de formação em diferentes tipos celulares por elas. Dada a abrangência no emprego das MSCs, há necessidade de se compreender melhor algumas propriedades relacionadas à diferenciação osteogênica, particularmente liga à biomateriais usados em engenharia de tecidos. Este projeto objetiva o desenvolvimento de uma metodologia de análise empregando-se a FT-Raman para identificação e quantificação de componentes bioquímicos presentes em meios de cultura condicionados por MSCs, com ou sem indução à diferenciação osteogênica. Todos os experimentos foram realizados entre as passagens 3 e 5. Para essas análises, as MSCs foram cultivadas sobre arcabouços de polímeros biorreabsorvíveis de poli (hidroxibutirato-co-hidroxivalerato) (PHBV) e o poli (ε-caprolactona) (PCL). As MSCs (GIBCO®) foram inoculadas nos polímeros puros e na mistura 75:25 de PHBV / PCL (amostras densas e porosas). As células foram mantidas em DMEM (com baixa glicose) contendo GlutaMAX® e 10% de SFB a 37oC com 5% de CO2 por 21 dias. A própria placa foi usada como controle. Os meios de cultura condicionados foram coletados e analisadas em FT-Raman para sondagem de grupos funcionais, bem como possíveis variações moleculares associadas com a diferenciação e metabolismo celular. Foi possível discernir grupos funcionais de moléculas específicas no meio condicionado, como colesterol, fosfatidilinositol, triglicerídeos, forma Beta de polipeptídeos, regiões de amida e ligações de hidrogênio de proteínas, além da expressão de DNA. Na presente avaliação, a FT-Raman apresentou como uma técnica de resolução limitada, uma vez que modos vibracionais de estiramento próximos ou mesmo iguais podem ser expressos por moléculas diferente, dificultando a análise. Não houve variações nas leituras entre as amostras estudadas, concluindo-se que a FT-Raman não atendeu às expectativas nas condições estudadas.

Effect of pH on the chelation between strontium ions and decellularized small intestinal submucosal sponge scaffolds / 北京大学学报(医学版)

OBJECTIVE@#To investigate the preparation of decellularized small intestinal submucosa (dSIS) sponge scaffolds with chelated strontium (Sr) ions at different pH values, and to select the appropriate pH values for synthesizing Sr/dSIS scaffolds using the physicochemical properties and biocompatibility of the scaffolds as evaluation indexes.@*METHODS@#(1) Sr/dSIS scaffolds preparation and grouping: After mixing dSIS solution and strontium chloride solution in equal volumes, adjusting pH of the solution to 3, 5, 7, and 9 respectively, porous scaffolds were prepared by freeze-drying method after full reaction at 37℃, which were named Sr/dSIS-3, -5, -7, and -9 respectively, and the dSIS scaffolds were used as the control group. (2) Physicochemical property evaluation: The bulk morphology of the scaffolds was observed in each group, the microscopic morphology analyzed by scanning electron microscopy, and the porosity and pore size determined, the surface elements analyzed by energy spectroscopy, the structure of functional groups analyzed by infrared spectroscopy, the chelation rate determined by atomic spectrophotometry, the water absorption rate detected by using specific gravity method, and the compression strength evaluated by universal mechanical testing machine.(3) Biocompatibility evaluation: The cytotoxicity and proliferative effect to bone mesenchymal stem cells (BMSCs) of each group were evaluated by Calcein-AM/PI double staining method.@*RESULTS@#Scanning electron microscopy showed that the scaffolds of each group had an interconnected three-dimensional porous structure with no statistical difference in pore size and porosity. Energy spectrum analysis showed that strontium could be detected in Sr/dSIS-5, -7 and -9 groups, and strontium was uniformly distributed in the scaffolds. Functional group analysis further supported the formation of chelates in the Sr/dSIS-5, -7 and -9 groups. Chelation rate analysis showed that the Sr/dSIS-7 group had the highest strontium chelation rate, which was statistically different from the other groups (P < 0.05). The scaffolds in all the groups had good water absorption. The scaffolds in Sr/dSIS-5, -7 and -9 groups showed significantly improved mechanical properties compared with the control group (P < 0.05). The scaffolds in all the groups had good biocompatibility, and the Sr/dSIS-7 group showed the best proliferation of BMSCs.@*CONCLUSION@#When pH was 7, the Sr/dSIS scaffolds showed the highest strontium chelation rate and the best proliferation effect of BMSCs, which was the ideal pH value for the preparation of the Sr/dSIS scaffolds.

Research, development and application of collagen: a review / 生物工程学报

Collagen, which widely exists in skin, bone, muscle and other tissues, is a major structural protein in mammalian extracellular matrix. It participates in cell proliferation, differentiation, migration and signal transmission, plays an important role in tissue support and repair and exerts a protective effect. Collagen is widely used in tissue engineering, clinical medicine, food industry, packaging materials, cosmetics and medical beauty due to its good biological characteristics. This paper reviews the biological characteristics of collagen and its application in bioengineering research and development in recent years. Finally, we prospect the future application of collagen as a biomimetic material.

Research Advances in Medical Materials and Products for Soft Tissue Repairs / 中国医疗器械杂志

Soft tissue is an indispensable tissue in human body. It plays an important role in protecting the body from external physical, chemical or biological factors. Mild soft tissue injuries can self-heal, while severe soft tissue injuries may require related treatment. Natural polymers (such as chitosan, hyaluronic acid, and collagen) and synthetic polymers (such as polyethylene glycol and polylactic acid) exhibit good biocompatibility, biodegradability and low toxicity. It can be used for soft tissue repairs for antibacterial, hemostatic and wound healing purposes. Their related properties can be enhanced through modification or preparation of composite materials. Commonly used soft tissue repairs include wound dressings, biological patches, medical tissue adhesives, and tissue engineering scaffolds. This study introduces the properties, mechanisms of action and applications of various soft tissue repair medical materials, including chitosan, hyaluronic acid, collagen, polyethylene glycol and polylactic acid, and provides an outlook on the application prospects of soft tissue repair medical materials and products.

Research status and prospect of tissue engineering technology in treatment of atrophic rhinitis / 中国修复重建外科杂志

OBJECTIVE@#To review the research progress of the feasibility of a new treatment method for atrophic rhinitis (ATR) based on tissue engineering technology (seed cells, scaffold materials, and growth factors), and provide new ideas for the treatment of ATR.@*METHODS@#The literature related to ATR was extensively reviewed. Focusing on the three aspects of seed cells, scaffold materials, and growth factors, the recent research progress of ATR treatment was reviewed, and the future directions of tissue engineering technology to treat ATR were proposed.@*RESULTS@#The pathogenesis and etiology of ATR are still unclear, and the effectiveness of the current treatments are still unsatisfactory. The construction of a cell-scaffold complex with sustained and controlled release of exogenous cytokines is expected to reverse the pathological changes of ATR, promoting the regeneration of normal nasal mucosa and reconstructing the atrophic turbinate. In recent years, the research progress of exosomes, three-dimensional printing, and organoids will promote the development of tissue engineering technology for ATR.@*CONCLUSION@#Tissue engineering technology can provide a new treatment method for ATR.

Automated Assessment of Cell Infiltration and Removal in Decellularized Scaffolds - Experimental Study in Rabbits / Avaliação automatizada da infiltração e remoção celular em scaffolds descelularizados - Estudo experimental em coelhos

Abstract Objective Semiquantitative and automated measurement of nuclear material removal and cell infiltration in decellularized tendon scaffolds (DTSs). Method 16 pure New Zealand rabbits were used, and the gastrocnemius muscle tendon was collected bilaterally from half of these animals (16 tendons collected); 4 were kept as control and 12 were submitted to the decellularization protocol (DTS). Eight of the DTSs were used as an in vivo implant in the experimental rotator cuff tear (RCT) model, and the rest, as well as the controls, were used in the semiquantitative and automated evaluation of nuclear material removal. The eight additional rabbits were used to make the experimental model of RCT and subsequent evaluation of cellular infiltration after 2 or 8 weeks, within the DTS. Results The semiquantitative and automated analysis used demonstrated a removal of 79% of nuclear material (p< 0.001 and power > 99%) and a decrease of 88% (p < 0.001 and power >99%) in the area occupied by nuclear material after the decellularization protocol. On cell infiltration in DTS, an increase of 256% (p < 0.001 and power >99%) in the number of cells within the DTS was observed in the comparison between 2 and 8 weeks postoperatively. Conclusion The proposed semiquantitative and automated measurement method was able to objectively measure the removal of nuclear material and cell infiltration in DTS.

Resumo Objetivo Mensuração semiquantitativa e automatizada da remoção de material nuclear e da infiltração celular em scaffolds tendinosos descelularizados (STDs). Método Foram utilizados 16 coelhos Nova Zelândia puros, sendo o tendão do músculo gastrocnêmio coletado bilateralmente de metade destes animais (16 tendões coletados); 4 foram mantidos como controle e 12 foram submetidos ao protocolo de descelularização (STD). Dos STDs, 8 foram utilizados como implante in vivo no modelo experimental de lesão do manguito rotador (LMR) e os restantes, assim como os controles, foram utilizados na avaliação semiquantitativa e automatizada da remoção de material nuclear. Os oito coelhos adicionais foram utilizados na confecção do modelo experimental de LMR e posterior avaliação da infiltração celular após 2 ou 8 semanas, dentro do STD. Resultados A análise semiquantitativa e automatizada utilizada demonstrou uma remoção de 79% do material nuclear (p< 0,001 e poder > 99%) e uma diminuição de 88% (p< 0,001 e poder > 99%) na área ocupada por material nuclear após o protocolo de descelularização. Sobre a infiltração celular no STD, foi observado um aumento de 256% (p< 0,001 e poder > 99%) no número de células dentro do STD na comparação entre 2 e 8 semanas de pós-operatório. Conclusão O método de mensuração semiquantitativo e automatizado proposto foi capaz de mensurar objetivamente a remoção de material nuclear e a infiltração celular no STD.

The effect of scaffold hydroxyapatite derived from portunus pelagicus shell on the expression of fibroblast growth factor-2 (fgf-2) and bone morphogenetic proteins-2 (bmp -2) in the extraction sockets of cavia cobaya / El efecto del scaffold de hidroxiapatita derivada de portunus pelagicus sobre la expresión del factor de crecimiento de fibroblastos-2 (FGF-2) y las proteínas morfogenéticas óseas-2 (BMP-2) en los alvéolos dentarios de cavia cobaya

Objetive: To determine the expression of Fibroblast Growth Factor (FGF)-2 and Bone Morphogenetic Protein (BMP)-2 after application of scaffold hydroxyapatite from Rajungan crab shell (Portunus pelagicus) in the tooth extraction socket of Cavia cobaya. Material and Methods: This study used a post-test only control group design with 28 Cavia cobaya separated into two groups, control and treatment group. The left mandibular incisor was extracted, and socket preservation was conducted. A hydroxyapatite graft derived from crab shells was mixed with gelatin and eventually turned into a scaffold, which was afterward put into the extraction socket. After 7 days and 14 days, each group was terminated and examined using immunohistochemical staining to observe the expression of FGF-2 and BMP-2. One-Way Anova and Tukey HSD were used to examine the research data. Results: FGF-2 and BMP-2 expressions were observed higher in the group that received hydroxyapatite scaffold at the post-extraction socket than those in the group that did not receive hydroxyapatite scaffold. Conclusion: The application of a hydroxyapatite scaffold from Rajungan crab shell (Portunus pelagicus) to the tooth extraction socket can increase FGF-2 and BMP-2 expression.

Objetivo: Determinar la expresión del factor de crecimiento de fibroblastos (FGF)-2 y la proteína morfogenética ósea (BMP)-2 después de la aplicación de hidroxiapatita de andamio de caparazón de cangrejo Rajungan (Portunus pelagicus) en el alvéolo de extracción dental de Cavia cobaya. Material y Métodos: Este estudio utilizó un diseño de grupo de control solo posterior a la prueba con 28 Cavia cobaya separados en dos grupos, grupo de control y grupo de tratamiento. Se extrajo el incisivo mandibular izquierdo y se realizó la preservación del alvéolo. Un injerto de hidroxiapatita derivado de caparazones de cangrejo se mezcló con gelatina y se convirtió en un andamio, que luego se colocó en el alvéolo de extracción. Después de 7 días y 14 días, se terminó cada grupo y se examinó mediante tinción inmunohistoquímica para observar la expresión de FGF-2 y BMP-2. Se utilizaron One-Way Anova y Tukey HSD para examinar los datos de la investigación. Resultados: Las expresiones de FGF-2 y BMP-2 se observaron más altas en el grupo que recibió la estructura de hidroxiapatita en el alvéolo posterior a la extracción que en el grupo que no recibió la estructura de hidroxiapatita. Conclusión: La aplicación de un andamio de hidroxiapatita de caparazón de cangrejo Rajungan (Portunus pelagicus) al alvéolo de extracción dental puede aumentar la expresión de FGF-2 y BMP-2.

Células madre en odontología: nuevas perspectivas / Stem cells in dentistry: new perspectives

En el campo de la odontología, prevalecen actualmente alternativas terapéuticas con una filosofía conservadora. Sin embargo, con el advenimiento de los tratamientos con células madre (CM), se amplían las posibilidades terapéuticas, que buscan la combinación y el equilibrio entre la intervención tradicional y las posibilidades de reposición de estructuras anatómicas dañadas, a través de la regeneración de tejidos utilizando células madre o sus derivados (AU)

In the dentistry field, therapeutic alternatives with a conservative philosophy currently prevail. However, with the advent of stem cell (SC) treatments, therapeutic possibilities are expanding, seeking a combination and balance between traditional intervention and the pos- sibility of replacing damaged anatomical structures through tissue regeneration, using stem cells or their derivatives (AU)

Decellularized extracellular matrix mediates tissue construction and regeneration / 医学前沿

Contributing to organ formation and tissue regeneration, extracellular matrix (ECM) constituents provide tissue with three-dimensional (3D) structural integrity and cellular-function regulation. Containing the crucial traits of the cellular microenvironment, ECM substitutes mediate cell-matrix interactions to prompt stem-cell proliferation and differentiation for 3D organoid construction in vitro or tissue regeneration in vivo. However, these ECMs are often applied generically and have yet to be extensively developed for specific cell types in 3D cultures. Cultured cells also produce rich ECM, particularly stromal cells. Cellular ECM improves 3D culture development in vitro and tissue remodeling during wound healing after implantation into the host as well. Gaining better insight into ECM derived from either tissue or cells that regulate 3D tissue reconstruction or organ regeneration helps us to select, produce, and implant the most suitable ECM and thus promote 3D organoid culture and tissue remodeling for in vivo regeneration. Overall, the decellularization methodologies and tissue/cell-derived ECM as scaffolds or cellular-growth supplements used in cell propagation and differentiation for 3D tissue culture in vitro are discussed. Moreover, current preclinical applications by which ECM components modulate the wound-healing process are reviewed.

Extrapolating neurogenesis of mesenchymal stem/stromal cells on electroactive and electroconductive scaffolds to dental and oral-derived stem cells / 国际口腔科学杂志·英文版

The high neurogenic potential of dental and oral-derived stem cells due to their embryonic neural crest origin, coupled with their ready accessibility and easy isolation from clinical waste, make these ideal cell sources for neuroregeneration therapy. Nevertheless, these cells also have high propensity to differentiate into the osteo-odontogenic lineage. One strategy to enhance neurogenesis of these cells may be to recapitulate the natural physiological electrical microenvironment of neural tissues via electroactive or electroconductive tissue engineering scaffolds. Nevertheless, to date, there had been hardly any such studies on these cells. Most relevant scientific information comes from neurogenesis of other mesenchymal stem/stromal cell lineages (particularly bone marrow and adipose tissue) cultured on electroactive and electroconductive scaffolds, which will therefore be the focus of this review. Although there are larger number of similar studies on neural cell lines (i.e. PC12), neural stem/progenitor cells, and pluripotent stem cells, the scientific data from such studies are much less relevant and less translatable to dental and oral-derived stem cells, which are of the mesenchymal lineage. Much extrapolation work is needed to validate that electroactive and electroconductive scaffolds can indeed promote neurogenesis of dental and oral-derived stem cells, which would thus facilitate clinical applications in neuroregeneration therapy.

The osteogenesis of Ginsenoside Rb1 incorporated silk/micro-nano hydroxyapatite/sodium alginate composite scaffolds for calvarial defect / 国际口腔科学杂志·英文版

Ginsenoside Rb1, the effective constituent of ginseng, has been demonstrated to play favorable roles in improving the immunity system. However, there is little study on the osteogenesis and angiogenesis effect of Ginsenoside Rb1. Moreover, how to establish a delivery system of Ginsenoside Rb1 and its repairment ability in bone defect remains elusive. In this study, the role of Ginsenoside Rb1 in cell viability, proliferation, apoptosis, osteogenic genes expression, ALP activity of rat BMSCs were evaluated firstly. Then, micro-nano HAp granules combined with silk were prepared to establish a delivery system of Ginsenoside Rb1, and the osteogenic and angiogenic effect of Ginsenoside Rb1 loaded on micro-nano HAp/silk in rat calvarial defect models were assessed by sequential fluorescence labeling, and histology analysis, respectively. It revealed that Ginsenoside Rb1 could maintain cell viability, significantly increased ALP activity, osteogenic and angiogenic genes expression. Meanwhile, micro-nano HAp granules combined with silk were fabricated smoothly and were a delivery carrier for Ginsenoside Rb1. Significantly, Ginsenoside Rb1 loaded on micro-nano HAp/silk could facilitate osteogenesis and angiogenesis. All the outcomes hint that Ginsenoside Rb1 could reinforce the osteogenesis differentiation and angiogenesis factor's expression of BMSCs. Moreover, micro-nano HAp combined with silk could act as a carrier for Ginsenoside Rb1 to repair bone defect.

Biocompatible chitosan/polyethylene glycol/multi-walled carbon nanotube composite scaffolds for neural tissue engineering / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Carbon nanotube (CNT) composite materials are very attractive for use in neural tissue engineering and biosensor coatings. CNT scaffolds are excellent mimics of extracellular matrix due to their hydrophilicity, viscosity, and biocompatibility. CNTs can also impart conductivity to other insulating materials, improve mechanical stability, guide neuronal cell behavior, and trigger axon regeneration. The performance of chitosan (CS)/polyethylene glycol (PEG) composite scaffolds could be optimized by introducing multi-walled CNTs (MWCNTs). CS/PEG/CNT composite scaffolds with CNT content of 1%, 3%, and 5% (1%=0.01 g/mL) were prepared by freeze-drying. Their physical and chemical properties and biocompatibility were evaluated. Scanning electron microscopy (SEM) showed that the composite scaffolds had a highly connected porous structure. Transmission electron microscope (TEM) and Raman spectroscopy proved that the CNTs were well dispersed in the CS/PEG matrix and combined with the CS/PEG nanofiber bundles. MWCNTs enhanced the elastic modulus of the scaffold. The porosity of the scaffolds ranged from 83% to 96%. They reached a stable water swelling state within 24 h, and swelling decreased with increasing MWCNT concentration. The electrical conductivity and cell adhesion rate of the scaffolds increased with increasing MWCNT content. Immunofluorescence showed that rat pheochromocytoma (PC12) cells grown in the scaffolds had characteristics similar to nerve cells. We measured changes in the expression of nerve cell markers by quantitative real-time polymerase chain reaction (qRT-PCR), and found that PC12 cells cultured in the scaffolds expressed growth-associated protein 43 (GAP43), nerve growth factor receptor (NGFR), and class III β‍-tubulin (TUBB3) proteins. Preliminary research showed that the prepared CS/PEG/CNT scaffold has good biocompatibility and can be further applied to neural tissue engineering research.

Research progress on effect of magnetic nanoparticle composite scaffold on osteogenesis / 浙江大学学报·医学版

Magnetic nanoparticles (MNP) have been widely used as biomaterials due to their unique magnetic responsiveness and biocompatibility, which also can promote osteogenic differentiation through their inherent micro-magnetic field. The MNP composite scaffold retains its superparamagnetism, which has good physical, mechanical and biological properties with significant osteogenic effects and . Magnetic field has been proved to promote bone tissue repair by affecting cell metabolic behavior. MNP composite scaffolds under magnetic field can synergically promote bone tissue repair and regeneration, which has great application potential in the field of bone tissue engineering. This article summarizes the performance of magnetic composite scaffold, the research progress on the effect of MNP composite scaffold with magnetic fields on osteogenesis, to provide reference for further research and clinical application.

Application of microcarrier technology in cartilage repairing: a review / 生物工程学报

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.

Research progress of circumferential tracheal reconstruction via tissue-engineered trachea / 中华外科杂志

Tissue engineering, as a new technology, provides a new avenue for the reconstruction of circumferential tracheal defects, which has always been a tremendous challenge for surgeons around the world. Recently, technologies such as decellularization, 3-dimensional printing, electrospinning and cell sheet have significantly enhanced the chondrification. Implantation of epithelial cells or transplantation of epithelial cell sheets also has accelerated the process of epithelialization. And pedicle muscle flap proved to be a reliable strategy for vascularization of tissue-engineered trachea. But it is still a huge challenge to achieve circumferential tracheal functional reconstruction. The key difficulty lies in how to simultaneously realize the functional regeneration of cartilage, blood vessels and epithelial tissues of tissue-engineered trachea. Therefore, how to integrate the above schemes and finally realize segmental tracheal reconstruction needs further research. This article reviews the research progress of repairing circumferential tracheal defects based on tissue engineering technology.

Effects of different crosslinking treatments on the properties of decellularized small intestinal submucosa porous scaffolds / 北京大学学报(医学版)

OBJECTIVE@#To compare the effects of three different crosslinkers on the biocompatibility, physical and chemical properties of decellularized small intestinal submucosa (SIS) porous scaffolds.@*METHODS@#The SIS porous scaffolds were prepared by freeze-drying method and randomly divided into three groups, then crosslinked by glutaraldehyde (GA), 1-ethyl-3-(3-dimethylaminopropyl) carbodi-imide (EDC) and procyanidine (PA) respectively. To evaluate the physicochemical property of each sample in different groups, the following experiments were conducted. Macroscopic morphologies were observed and recorded. Microscopic morphologies of the scaffolds were observed using field emission scanning electron microscope (FESEM) and representative images were selected. Computer software (ImageJ) was used to calculate the pore size and porosity. The degree of crosslinking was determined by ninhydrin experiment. Collagenase degradation experiment was performed to assess the resistance of SIS scaffolds to enzyme degradation. To evaluate the mechanical properties, universal mechanical testing machine was used to determine the stress-strain curve and compression strength was calculated. Human bone marrow mesenchymal cells (hBMSCs) were cultured on the scaffolds after which cytotoxicity and cell proliferation were assessed.@*RESULTS@#All the scaffolds remained intact after different crosslinking treatments. The FESEM images showed uniformed interconnected micro structures of scaffolds in different groups. The pore size of EDC group[(161.90±13.44) μm] was significantly higher than GA group [(149.50±14.65) μm] and PA group[(140.10±12.06) μm] (P < 0.05). The porosity of PA group (79.62%±1.14%) was significantly lower than EDC group (85.11%±1.71%) and GA group (84.83%±1.89%) (P < 0.05). PA group showed the highest degree of crosslinking whereas the lowest swelling ratio. There was a significant difference in the swelling ratio of the three groups (P < 0.05). Regarding to the collagenase degradation experiment, the scaffolds in PA group showed a significantly lower weight loss rate than the other groups after 7 days degradation. The weight loss rates of GA group were significantly higher than those of the other groups on day 15, whereas the PA group had the lowest rate after 10 days and 15 days degradation. PA group showed better mechanical properties than the other two groups. More living cells could be seen in PA and EDC groups after live/dead cell staining. Additionally, the proliferation rate of hBMCSs was faster in PA and EDC groups than in GA group.@*CONCLUSION@#The scaffolds gained satisfying degree of crosslinking after three different crosslinking treatments. The samples after PA and EDC treatment had better physicochemical properties and biocompatibility compared with GA treatment. Crosslinking can be used as a promising and applicable method in the modification of SIS scaffolds.

Microorganism-derived biological macromolecules for tissue engineering / 医学前沿

According to literature, certain microorganism productions mediate biological effects. However, their beneficial characteristics remain unclear. Nowadays, scientists concentrate on obtaining natural materials from live creatures as new sources to produce innovative smart biomaterials for increasing tissue reconstruction in tissue engineering and regenerative medicine. The present review aims to introduce microorganism-derived biological macromolecules, such as pullulan, alginate, dextran, curdlan, and hyaluronic acid, and their available sources for tissue engineering. Growing evidence indicates that these materials can be used as biological material in scaffolds to enhance regeneration in damaged tissues and contribute to cosmetic and dermatological applications. These natural-based materials are attractive in pharmaceutical, regenerative medicine, and biomedical applications. This study provides a detailed overview of natural-based biomaterials, their chemical and physical properties, and new directions for future research and therapeutic applications.

Decoloración coronaria inducida por la utilización de Biodentine y MTA blanco en procedimientos de regeneración pulpar: estudio ex vivo / Coronal discoloration induced by the use of Biodentine and white MTA in pulp regeneration procedures: an ex-vivo study

Se comparó el grado de decoloración de la corona clínica en piezas dentarias anteriores humanas ex-traídas, sometidas a procedimientos de regeneración endodóntica, utilizando MTA blanco o sustituto bioac-tivo de la dentina (Biodentine) como barrera cervical, en presencia de coágulo sanguíneo como andamio. En total se prepararon 24 piezas dentarias anterio-res superiores humanas que fueron divididas en dos grupos control (GC) y dos grupos experimentales (GE). Cada uno incluía 6 piezas dentarias. En los GE se colo-có sangre humana fresca en el interior del conducto, y se confeccionó una barrera de Biodentine (GE3) o MTA (GE4). En los GC se colocó una torunda de algo-dón estéril saturada con solución fisiológica estéril, y se confeccionó una barrera de Biodentine (GC1) o MTA (GC2). El color se evaluó de acuerdo con el espa-cio de color CIE L* a* b* utilizando imágenes fotográfi-cas digitales estandarizadas en dos puntos de tiempo: día 0 (T0) y día 35 (T35). La descripción de los datos in-cluyó mediana (Md), primer cuartil (Q1), tercer cuartil (Q3), media y desviación estándar (DE). Se emplea-ron las pruebas de los rangos con signo de Wilcoxon (RSW) y ANOVA de una vía; p < 0,05 fue considerado significativo. Cuando se comparó ∆E se observaron diferencias significativas entre GC1 y el resto de los materiales (p < 0,05). ∆E fue menor en GC1 (media ± DE; 2,1 ± 1,6) que en los grupos restantes que no pre-sentaron diferencias significativas entre sí. En base a estos resultados, la estabilización del coágulo san-guíneo, como así la limpieza de la cavidad previa a la colocación del Biodentine y el uso de barreras cervi-cales, es imprescindible para evitar la coloración de la corona clínica (AU)

Discoloration remains an unfavorable complication of otherwise successful regenerative endodontic procedure of immature teeth with necrotic pulp. Objective: Compare the degree of discoloration of extracted human teeth after regenerative endodontic procedures, using MTA or Biodentine as a cervical barrier with a blood clot as a scaffold. In total 24 human upper anterior teeth were prepared and divided into two control groups (CG) and two experimental groups (EG). In the EG, fresh human blood was placed inside the root and a Biodentine (GE3) or MTA (GE4) barrier was made in. A sterile cotton swab saturated with sterile physiological solution was placed in the GCs and a Biodentine (GC1) or MTA (GC2) barrier was made in. The color was evaluated according to the CIE L* a* b* color space using standardized digital photographic images at two time points: day 0 (T0) and day 35 (T35). The description of the data included median (Md), first quartile (Q1), third quartile (Q3), means, and standard deviation (SD). Wilcoxon signed rank tests (RSW) and one-way ANOVA were used. p < 0.05 was considered significant. When ∆E was compared, significant differences were observed between GC1 and the rest of the materials (p < 0.05). ∆E was lower in CG1 (mean ± SD; 2.1 ± 1.6) than in the remaining groups, which did not present significant differences between them. There was no significant difference between tooth discolorations with materials in the presence of blood. However, in the absence of blood, Biodentine exhibited less tooth discoloration than MTA (AU)