UNASSIGNED: To review the research progress on the application of three-dimensional (3D) bioprinting technology in auricle repair and reconstruction.
UNASSIGNED: The recent domestic and international research literature on 3D printing and auricle repair and reconstruction was extensively reviewed, and the concept of 3D bioprinting technology and research progress in auricle repair and reconstruction were summarized.
UNASSIGNED: The auricle possesses intricate anatomical structure and functionality, necessitating precise tissue reconstruction and morphological replication. Hence, 3D printing technology holds immense potential in auricle reconstruction. In contrast to conventional 3D printing technology, 3D bioprinting technology not only enables the simulation of auricular outer shape but also facilitates the precise distribution of cells within the scaffold during fabrication by incorporating cells into bioink. This approach mimics the composition and structure of natural tissues, thereby favoring the construction of biologically active auricular tissues and enhancing tissue repair outcomes.
UNASSIGNED: 3D bioprinting technology enables the reconstruction of auricular tissues, avoiding potential complications associated with traditional autologous cartilage grafting. The primary challenge in current research lies in identifying bioinks that meet both the mechanical requirements of complex tissues and biological criteria.
UNASSIGNED: 对3D生物打印技术在耳廓修复重建方面的应用研究进展作一综述。.
UNASSIGNED: 广泛查阅近年来国内外3D打印与耳廓修复重建相关研究文献，对3D生物打印技术概念及其在耳廓修复重建中的应用研究进展进行总结。.
UNASSIGNED: 耳廓具有复杂解剖结构和功能，需要精确的组织重建和形态复制，因此 3D打印技术在耳廓修复重建方面具有巨大应用潜力。与传统3D打印技术相比，3D生物打印技术不仅能模拟耳廓外形结构，还能将细胞与材料混合打印，在支架成型过程中实现细胞在支架内部精准分布，模拟天然组织组成及结构，更有利于构建具有生物活性功能的耳廓组织，从而提高修复效果。.
UNASSIGNED: 3D生物打印技术可以重建耳廓组织，能避免传统自体软骨移植相关并发症，寻找既符合耳廓组织机械性要求，又符合生物要求的生物墨水是目前研究的主要挑战。.

UNASSIGNED: To investigate the construction of a novel tissue engineered meniscus scaffold based on low temperature deposition three-dimenisonal (3D) printing technology and evaluate its biocompatibility.
UNASSIGNED: The fresh pig meniscus was decellularized by improved physicochemical method to obtain decellularized meniscus matrix homogenate. Gross observation, HE staining, and DAPI staining were used to observe the decellularization effect. Toluidine blue staining, safranin O staining, and sirius red staining were used to evaluate the retention of mucopolysaccharide and collagen. Then, the decellularized meniscus matrix bioink was prepared, and the new tissue engineered meniscus scaffold was prepared by low temperature deposition 3D printing technology. Scanning electron microscopy was used to observe the microstructure. After co-culture with adipose-derived stem cells, the cell compatibility of the scaffolds was observed by cell counting kit 8 (CCK-8), and the cell activity and morphology were observed by dead/live cell staining and cytoskeleton staining. The inflammatory cell infiltration and degradation of the scaffolds were evaluated by subcutaneous experiment in rats.
UNASSIGNED: The decellularized meniscus matrix homogenate appeared as a transparent gel. DAPI and histological staining showed that the immunogenic nucleic acids were effectively removed and the active components of mucopolysaccharide and collagen were remained. The new tissue engineered meniscus scaffolds was constructed by low temperature deposition 3D printing technology and it had macroporous-microporous microstructures under scanning electron microscopy. CCK-8 test showed that the scaffolds had good cell compatibility. Dead/live cell staining showed that the scaffold could effectively maintain cell viability (>90%). Cytoskeleton staining showed that the scaffolds were benefit for cell adhesion and spreading. After 1 week of subcutaneous implantation of the scaffolds in rats, there was a mild inflammatory response, but no significant inflammatory response was observed after 3 weeks, and the scaffolds gradually degraded.
UNASSIGNED: The novel tissue engineered meniscus scaffold constructed by low temperature deposition 3D printing technology has a graded macroporous-microporous microstructure and good cytocompatibility, which is conducive to cell adhesion and growth, laying the foundation for the in vivo research of tissue engineered meniscus scaffolds in the next step.
UNASSIGNED: 基于低温沉积3D打印技术构建新型组织工程半月板支架，评价该支架理化性质及生物相容性。.
UNASSIGNED: 取新鲜猪膝关节半月板，采用改良物理化学联合方法脱细胞处理，获得脱细胞半月板基质匀浆；经大体观察、HE及DAPI染色观察脱细胞效果，甲苯胺蓝、番红O及天狼猩红染色评估黏多糖和胶原保留情况。然后制备脱细胞半月板基质生物墨水，通过低温沉积3D打印技术制备新型组织工程半月板支架。扫描电镜观察微观结构；与脂肪来源干细胞共培养后，采用细胞计数试剂盒8（cell counting kit 8，CCK-8）检测支架细胞相容性，死/活细胞染色和细胞骨架染色观察细胞活性和形态；植入大鼠皮下后组织学染色评估支架炎症细胞浸润与降解情况。.
UNASSIGNED: 脱细胞处理后半月板基质匀浆呈透明凝胶状，DAPI和组织学染色示免疫原性的核酸去除，同时黏多糖及胶原成分保留。采用低温沉积3D打印技术成功构建新型组织工程半月板支架，扫描电镜示支架呈分级大孔-微孔的微观结构；CCK-8检测示支架具有良好细胞相容性；死/活细胞染色示支架可有效维持细胞活性（>90%）；细胞骨架染色示支架有利于细胞黏附和铺展；支架植入大鼠皮下1周后有轻度炎症反应，3周后未见明显炎症反应，并可见支架逐步降解。.
UNASSIGNED: 基于低温沉积3D打印技术构建的新型组织工程半月板支架具有分级大孔-微孔的微观结构和良好细胞相容性，有利于细胞黏附和生长，为下一步体内研究奠定基础。.

Dermal scarring from motor vehicle accidents, severe burns, military blasts, etc. is a major problem affecting over 80 million people worldwide annually, many of whom suffer from debilitating hypertrophic scar contractures. These stiff, shrunken scars limit mobility, impact quality of life, and cost millions of dollars each year in surgical treatment and physical therapy. Current tissue engineered scaffolds have mechanical properties akin to unwounded skin, but these collagen-based scaffolds rapidly degrade over 2 months, premature to dampen contracture occurring 6-12 months after injury. This study demonstrates a tissue engineered scaffold can be manufactured from a slow-degrading viscoelastic copolymer, poly(ι-lactide-co-ε-caprolactone), with physical and mechanical characteristics to promote tissue ingrowth and support skin-grafts. Copolymers were synthesized via ring-opening polymerization. Solvent casting/particulate leaching was used to manufacture 3D porous scaffolds by mixing copolymers with particles in an organic solvent followed by casting into molds and subsequent particle leaching with water. Scaffolds characterized through SEM, micro-CT, and tensile testing confirmed the required thickness, pore size, porosity, modulus, and strength for promoting skin-graft bioincorporation and dampening fibrosis in vivo. Scaffolds were Oxygen Plasma Treatment and collagen coated to encourage cellular proliferation. Porosity ranging from 70% to 90% was investigated in a subcutaneous murine model and found to have no clinical effect on tissue ingrowth. A swine full-thickness skin wound model confirmed through histology and Computer Planimetry that scaffolds promote skin-graft survival, with or without collagen coating, with equal safety and efficacy as a commercially available tissue engineered scaffold. This study validates a scalable method to create poly(ι-lactide-co-ε-caprolactone) scaffolds with appropriate characteristics and confirms in mouse and swine wound models that the scaffolds are safe and effective at supporting skin-grafts. The results of this study have brought us closer towards developing an alternative technology that supports skin grafts with the potential to investigate long-term hypertrophic scar contractures.

Tissue engineered scaffolds (TES) hold promise for improving the outcome of cell-based therapeutic strategies for a variety of biomedical scenarios, including musculoskeletal injuries, soft tissue repair, and spinal cord injury. Key to TES research and development, and clinical use, is the ability to longitudinally monitor TES location, orientation, integrity, and microstructure following implantation. Here, we describe a strategy for using microcomputed tomography (microCT) to visualize TES following implantation into mice. TES were doped with highly radiopaque gadolinium oxide nanocrystals and were implanted into the hind limbs of mice. Mice underwent serial microCT over 23 weeks. TES were clearly visible over the entire time course. Alginate scaffolds underwent a 20% volume reduction over the first 6 weeks, stabilizing over the next 17 weeks. Agarose scaffold volumes were unchanged. TES attenuation was also unchanged over the entire time course, indicating a lack of nanocrystal dissolution or leakage. Histology at the implant site showed the presence of very mild inflammation, typical for a mild foreign body reaction. Blood work indicated marked elevation in liver enzymes, and hematology measured significant reduction in white blood cell counts. While extrapolation of the X-ray induced effects on hematopoiesis in these mice to humans is not straightforward, clearly this is an area for careful monitoring. Taken together, these data lend strong support that doping TES with radiopaque nanocrystals and performing microCT imaging, represents a possible strategy for enabling serial in vivo monitoring of TES.

OBJECTIVE: To review the recent research progress of acellular fish skin as a tissue engineered scaffold, and to analyze the feasibility and risk management in clinical application.
METHODS: The research and development, application status of acellular fish skin as a tissue engineered scaffold were comprehensively analyzed, and then several key points were put forward.
RESULTS: Acellular fish skin has a huge potential in clinical practice as novel acellular extracellular matrix, but there have been no related research reports up to now in China. As an emerging point of translational medicine, investigation of acellular fish skin is mainly focused on artificial skin, surgical patch, and wound dressings.
CONCLUSIONS: Development of acellular fish skin-based new products is concerned to be clinical feasible and necessary, but a lot of applied basic researches should be carried out.
UNASSIGNED: 分析脱细胞鱼皮基质作为新型组织工程支架材料的最新研究进展，讨论该材料用于医学临床的可行性及风险管理。.
UNASSIGNED: 基于对脱细胞鱼皮基质研究最新进展的广泛调研，综合分析其研发、应用现况，提出应重点关注的关键问题。.
UNASSIGNED: 脱细胞鱼皮基质作为新型细胞外基质有巨大的临床应用潜力，但我国在该领域的研究几乎空白，国外对该类产品的转化医学研究刚刚兴起，主要集中于人工皮肤、外科补片、创伤敷料等方面。.
UNASSIGNED: 脱细胞鱼皮基质作为组织工程支架新产品的开发具有良好的临床可行性和必要性，但作为新策略、新产品尚需进行大量的应用基础研究。.

OBJECTIVE: To fabricate in situ crosslinking hyaluronic acid hydrogel and evaluate its biocompatibility in vitro.
METHODS: The acrylic acid chloride and polyethylene glycol were added to prepare crosslinking agent polyethylene glycol acrylate (PEGDA), and the molecular structure of PEGDA was analyzed by Flourier transformation infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy. Hyaluronic acid hydrogel was chemically modified to prepare hyaluronic acid thiolation (HA-SH). And the degree of HA-SH was analyzed qualitatively and quantitatively by Ellman method. HA-SH solution in concentrations (W/V) of 0.5%, 1.0%, and 1.5% and PEGDA solution in concentrations (W/V) of 2%, 4%, and 6% were prepared with PBS. The two solutions were mixed in different ratios, and in situ crosslinking hyaluronic acid hydrogel was obtained; the crosslinking time was recorded. The cellular toxicity of in situ crosslinking hyaluronic acid hydrogel (1.5% HA-SH and 4% PEGDA mixed) was tested by L929 cells. Meanwhile, the biocompatibility of hydrogel was tested by co-cultured with human bone mesenchymal stem cells (hBMSCs).
RESULTS: Flourier transformation infrared spectroscopy showed that most hydroxyl groups were replaced by acrylate groups; 1H nuclear magnetic resonance spectroscopy showed 3 characteristic peaks of hydrogen representing acrylate and olefinic bond at 5-7 ppm. The thiolation yield of HA-SH was 65.4%. In situ crosslinking time of hyaluronic acid hydrogel was 2 to 70 minutes in the PEGDA concentrations of 2%-6% and HA-SH concentrations of 0.5%-1.5%. The hyaluronic acid hydrogel appeared to be transparent. The toxicity grade of leaching solution of hydrogel was grade 1. hBMSCs grew well and distributed evenly in hydrogel with a very high viability.
CONCLUSIONS: In situ crosslinking hyaluronic acid hydrogel has low cytotoxicity, good biocompatibility, and controllable crosslinking time, so it could be used as a potential tissue engineered scaffold or repairing material for tissue regeneration.
UNASSIGNED: 制备原位交联透明质酸水凝胶，并初步评价其体外生物相容性。.
UNASSIGNED: 采用醇钠-酰氯法将丙烯酰氯与聚乙二醇反应，制得交联剂聚乙二醇二丙烯酸酯（polyethylene glycol acrylate，PEGDA）；采用傅里叶变换红外光谱仪和核磁共振光谱仪检测其分子结构。取透明质酸经化学修饰制备巯基化透明质酸（hyaluronic acid thiolation，HA-SH），采用Ellman法检测其巯基含量并计算巯基化产率。采用PBS将HA-SH和PEGDA分别配制成一定浓度（W/V）溶液，其中HA-SH浓度为0.5%、1.0%及1.5%，PEGDA为2%、4%及6%，按照不同比例混合，获得原位交联透明质酸水凝胶，记录交联反应时间。取1.5%HA-SH、4%PEGDA制备的原位交联透明质酸水凝胶，以浸提法检测其细胞毒性；然后接种人BMSCs并培养72?h，荧光显微镜下观察细胞形态及生长情况，并行活/死细胞染色观察，评价材料生物相容性。.
UNASSIGNED: 傅里叶变换红外光谱仪分析显示，PEGDA中大多数羟基被丙烯酸酯基取代；核磁共振光谱仪分析显示，PEGDA在5～7 ppm出现3组表征丙烯酸酯基的特征峰。HA-SH的巯基化产率为65.4%。2%～6%PEGDA与0.5%～1.5%HA-SH经不同比例混合后，交联反应在2～70?min内完成；不同浓度及比例交联形成的水凝胶均呈透明状。透明质酸水凝胶浸提液细胞毒性分级为1级，满足生物医用材料的要求。培养72 h后，BMSCs在透明质酸水凝胶中分布均匀、生长良好，活/死细胞染色显示以绿染活细胞为主。.
UNASSIGNED: 原位交联透明质酸水凝胶具有细胞毒性低、体外生物相容性好、交联时间可控的优点，有望成为组织工程种子细胞载体或组织缺损填充材料。.

Within the framework of neurodegenerative disorder therapies, the fabrication of 3D eumelanin architectures represents a novel strategy to realize tissue-engineering scaffolds for neuronal cell growth and control by providing both mechanical support and biological signals. Here, an appropriate procedure combining electrospinning, spin coating and solid-state polymerization process is established to realize the scaffolds. For biological analysis, a human derived cell line SH-SY5Y from neuroblastoma is used. Cell maturation on eumelanin microfibers, random and aligned, is evaluated by using confocal analysis and specific markers of differentiating neurons (βIII tubulin and GAP-43 expression). Cell morphology is tested by SEM analysis and immunofluorescence techniques. As results, eumelanin coated microfibers prove capable to support biological response in terms of cell survival, adhesion and spreading and to promote cell differentiation toward a more mature neuronal phenotype as confirmed by GAP-43 expression over the culture.

Novel silk fibroin (SF) and carboxymethyl cellulose (CMC) composite nanofibrous scaffold (SFC) were developed to investigate their ability to nucleate bioactive nanosized calcium phosphate (Ca/P) by biomineralization for bone tissue engineering application. The composite nanofibrous scaffold was prepared by free liquid surface electrospinning method. The developed composite nanofibrous scaffold was observed to control the size of Ca/P particle (≤100nm) as well as uniform nucleation of Ca/P over the surface. The obtained nanofibrous scaffolds were fully characterized for their functional, structural and mechanical property. The XRD and EDX analysis depicted the development of apatite like crystals over SFC scaffolds of nanospherical in morphology and distributed uniformly throughout the surface of scaffold. Additionally, hydrophilicity as a measure of contact angle and water uptake capacity is higher than pure SF scaffold representing the superior cell supporting property of the SF/CMC scaffold. The effect of biomimetic Ca/P on osteogenic differentiation of umbilical cord blood derived human mesenchymal stem cells (hMSCs) studied in early and late stage of differentiation shows the improved osteoblastic differentiation capability as compared to pure silk fibroin. The obtained result confirms the positive correlation of alkaline phosphatase activity, alizarin staining and expression of runt-related transcription factor 2, osteocalcin and type1 collagen representing the biomimetic property of the scaffolds. Thus, the developed composite has been demonstrated to be a potential scaffold for bone tissue engineering application.