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1.
Bioengineering (Basel) ; 11(9)2024 Aug 27.
Article in English | MEDLINE | ID: mdl-39329610

ABSTRACT

The structure and composition of natural bone show gradient changes. Most bone scaffolds prepared by bone tissue engineering with single materials and structures present difficulties in meeting the needs of bone defect repair. Based on the structure and composition of natural long bones, this study proposed a new bone scaffold preparation technology, the dual-phase composite forming process. Based on the composite use of multiple biomaterials, a bionic natural long bone structure bone scaffold model with bone scaffold pore structure gradient and material concentration gradient changes along the radial direction was designed. Different from the traditional method of using multiple nozzles to achieve material concentration gradient in the scaffold, the dual-phase composite forming process in this study achieved continuous 3D printing preparation of bone scaffolds with gradual material concentration gradient by controlling the speed of extruding materials from two feed barrels into a closed mixing chamber with one nozzle. Through morphological characterization and mechanical property analysis, the results showed that BS-G (radial gradient long bone scaffolds prepared by the dual-phase composite forming process) had obvious pore structure gradient changes and material concentration gradient changes, while BS-T (radial gradient long bone scaffolds prepared by printing three concentrations of material in separate regions) had a discontinuous gradient with obvious boundaries between the parts. The compressive strength of BS-G was 1.00 ± 0.19 MPa, which was higher than the compressive strength of BS-T, and the compressive strength of BS-G also met the needs of bone defect repair. The results of in vitro cell culture tests showed that BS-G had no cytotoxicity. In a Sprague-Dawley rat experimental model, blood tests and key organ sections showed no significant difference between the experimental group and the control group. The prepared BS-G was verified to have good biocompatibility and lays a foundation for the subsequent study of the bone repair effect of radial gradient long bone scaffolds in large animals.

2.
J Mater Chem B ; 12(39): 10054-10067, 2024 Oct 09.
Article in English | MEDLINE | ID: mdl-39258439

ABSTRACT

The application of patch methods for repairing abdominal wall wounds presents a variety of challenges, such as adhesion and limited mobility due to inadequate mechanical strength and nonabsorbable materials. Among these complications, postoperative visceral adhesion and wound infection are particularly serious. In this study, a bilayered composite patch with a gelatin methacryloyl (GelMA)/sodium alginate (SA)-vancomycin (Van)@polycaprolactone (PCL) (GelMA/SA-Van@PCL) antibacterial layer was prepared via coaxial 3D printing and a polycaprolactone (PCL)-silicon dioxide (SiO2) antiadhesive layer (PCL-SiO2) was prepared via electrospinning and electrostatic spray for hernia repair. The evaluation of the physicochemical properties revealed that the composite patch had outstanding tensile properties (16 N cm-1), excellent swelling (swelling rate of 243.81 ± 12.52%) and degradation (degradation rate of 53.14 ± 3.02%) properties. Furthermore, the composite patch containing the antibiotic Van exhibited good antibacterial and long-term drug release properties. Both in vivo and in vitro experiments indicated that the composite patch displayed outstanding biocompatibility and antiadhesive properties and could prevent postoperative infections. In summary, the bilayered composite patch can effectively prevent postoperative complications while promoting tissue growth and repair and holds significant application potential in hernia repair.


Subject(s)
Abdominal Wall , Anti-Bacterial Agents , Gelatin , Polyesters , Printing, Three-Dimensional , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/chemical synthesis , Polyesters/chemistry , Polyesters/pharmacology , Animals , Abdominal Wall/surgery , Abdominal Wall/pathology , Gelatin/chemistry , Vancomycin/pharmacology , Vancomycin/chemistry , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Alginates/chemistry , Methacrylates/chemistry , Silicon Dioxide/chemistry , Silicon Dioxide/pharmacology , Escherichia coli/drug effects , Microbial Sensitivity Tests , Staphylococcus aureus/drug effects , Tissue Adhesions/prevention & control , Tissue Adhesions/drug therapy , Mice , Particle Size
3.
Nat Chem ; 2024 Sep 02.
Article in English | MEDLINE | ID: mdl-39223307

ABSTRACT

Triplex DNA structures, formed when a third DNA strand wraps around the major groove of DNA, are key molecular regulators and genomic threats. However, the regulatory network governing triplex DNA dynamics remains poorly understood. Here we reveal the binding and functional repertoire of proteins that interact with triplex DNA through chemoproteomic profiling in living cells. We develop a chemical probe that exhibits exceptional specificity towards triplex DNA. By employing a co-binding-mediated proximity capture strategy, we enrich triplex DNA interactome for quantitative proteomics analysis. This enables the identification of a comprehensive list of proteins that interact with triplex DNA, characterized by diverse binding properties and regulatory mechanisms in their native chromatin context. As a demonstration, we validate DDX3X as an ATP-independent triplex DNA helicase to unwind substrates with a 5' overhang to prevent DNA damage. Overall, our study provides a valuable resource for exploring the biology and translational potential of triplex DNA.

4.
3D Print Addit Manuf ; 11(2): e607-e618, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38689928

ABSTRACT

Large bone defects caused by congenital deformities and acquired accidents are increasing day by day. A large number of patients mainly rely on artificial bone for repair. However, artificial bone cannot fully imitate the structure and composition of human bone, resulting in a large gap with autologous bone function. Therefore, this article proposes a continuous preparation method for inorganic/organic biphasic composite gradient biomimetic bulk bone scaffolds. First, a controllable gradient hybrid forming platform for inorganic/organic dual-phase biomaterials was constructed, and the feeding control strategy was studied to achieve precise control of the feeding of sodium alginate/gelatin composite organic materials and hydroxyapatite inorganic materials. The speed is, respectively, sent from the corresponding feeding nozzle to the mixing chamber to realize the uniform mixing of the biphasic material and the extrusion of the composite material, and the inorganic/organic biphasic composite gradient biomimetic bone scaffold with gradual structure and composition is prepared. Second, to prove the superiority of the preparation method, the physicochemical and biological properties of the prepared scaffolds were evaluated. The test results showed that the morphological characteristics of the biphasic composite gradient bone scaffold showed good microscopic porosity and the structure and composition showed gradients. The mechanical properties are close to that of human bone tissue and in vitro cell experiments show that the scaffold has good biocompatibility and bioactivity. In conclusion, this article provides a new type of bone scaffold preparation technology and equipment for the field of tissue engineering, which has research value and application prospects.

5.
Mater Today Bio ; 25: 100940, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38298561

ABSTRACT

The use of endovascular stent-graft has become an important option in the treatment of aortic pathologies. However, the currently used endograft membranes have limited ability to prevent bacterial colonization. This makes them unsuitable for the treatment of mycotic aneurysms, as the infection is prone to progress after endograft implantation. Moreover, even in non-mycotic aortic pathologies, endograft infections can occur in the short or long term, especially for patients with diabetes mellitus or in immune insufficiency conditions. So, this study aimed to develop a kind of Ag-NPs-loaded endograft membrane by coaxial electrospinning technique, and a series of physical and chemical properties and biological properties of the Ag-NPs-loaded membrane were characterized. Animal experiments conducted in pigs confirmed that the Ag-NPs-loaded membrane was basically non-toxic, exhibited good biocompatibility, and effectively prevented bacterial growth in a mycotic aortic aneurysm model. In conclusion, the Ag-NPs-loaded membrane exhibited good biocompatibility, good anti-infection function and slow-release of Ag-NPs for long-term bacteriostasis. Thus, the Ag-NPs-loaded membrane might hold potential for preventing infection progression and treating mycotic aortic aneurysms in an endovascular way.

6.
Int J Biol Macromol ; 275(Pt 1): 129705, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38272418

ABSTRACT

Skin injuries and defects, as a common clinical issue, still cannot be perfectly repaired at present, particularly large-scale and infected skin defects. Therefore, in this work, a drug-loaded bilayer skin scaffold was developed for repairing full-thickness skin defects. Briefly, amoxicillin (AMX) was loaded on polycaprolactone (PCL) nanofiber via electrospinning to form the antibacterial nanofiber membrane (PCL-AMX) as the outer layer of scaffold to mimic epidermis. To maintain wound wettability and promote wound healing, external human epidermal growth factor (rhEGF) was loaded in sodium alginate-gelatin to form the hydrogel structure (SG-rhEGF) via 3D printing as inner layer of scaffold to mimic dermis. AMX and rhEGF were successfully loaded into the scaffold. The scaffold exhibited excellent physicochemical properties, with elongation at break and tensile modulus were 102.09 ± 6.74% and 206.83 ± 32.10 kPa, respectively; the outer layer was hydrophobic (WCA was 112.09 ± 4.67°), while the inner layer was hydrophilic (WCA was 48.87 ± 5.52°). Meanwhile, the scaffold showed excellent drug release and antibacterial characteristics. In vitro and in vivo studies indicated that the fabricated scaffold could enhance cell adhesion and proliferation, and promote skin wound healing, with favorable biocompatibility and great potential for skin regeneration and clinical application.


Subject(s)
Alginates , Anti-Bacterial Agents , Gelatin , Hydrogels , Nanofibers , Polyesters , Printing, Three-Dimensional , Skin , Tissue Scaffolds , Wound Healing , Gelatin/chemistry , Wound Healing/drug effects , Nanofibers/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Polyesters/chemistry , Alginates/chemistry , Alginates/pharmacology , Hydrogels/chemistry , Hydrogels/pharmacology , Tissue Scaffolds/chemistry , Skin/drug effects , Animals , Amoxicillin/pharmacology , Amoxicillin/chemistry , Humans , Drug Liberation
7.
3D Print Addit Manuf ; 10(5): 955-970, 2023 Oct 01.
Article in English | MEDLINE | ID: mdl-37886400

ABSTRACT

Tailored intestinal fistula stents with a hollow bent pipe structure prepared by using a three-axis bio-printing platform are often unsuitable due to low printing efficiency and quality caused by the unavoidable need for a supporting structure. Herein, a 5 + 1-axis 3D printing platform was built and developed for producing support-free intestinal fistula stents. A 3D model of the target stent shape and dimensions was treated by a dynamic slicing algorithm, which was then used to prepare a motion control code. Our printing method showed improved printing efficiency, superior stent surface properties and structure and ideal elasticity and mechanical strength to meet the mechanical requirements of the human body. Static simulations showed the importance of axial printing techniques, whereas the stent itself was shown to have excellent biocompatibility with wettability and cell proliferation tests. We present a customizable, efficient, and high-quality method with the potential for preparing bespoke stents for treating intestinal fistulas.

8.
Biomimetics (Basel) ; 8(5)2023 Sep 11.
Article in English | MEDLINE | ID: mdl-37754170

ABSTRACT

The coaxial electrospinning process has been widely used in the biomedical field, and its process parameters affect product quality seriously. In this paper, the influence of key process parameters of coaxial electrostatic spinning (solution concentration, electrospinning voltage, acceptance distance and liquid supply velocity) on the preparation of a membrane with Chitosan, Polyethylene oxide and nano-silver as the core layer and Polycaprolactone as the shell layer was studied. The optimal combination of key process parameters was obtained by using an orthogonal test, scanning electron microscope, transmission electron microscope and macro-characterization diagram. The results showed that the coaxial electrospun membrane had good mechanical properties (tensile strength is about 2.945 Mpa), hydrophilicity (the water contact angle is about 72.28°) and non-cytotoxicity, which was conducive to cell adhesion and proliferation. The coaxial electrospun membrane with nano-silver has an obvious inhibitory effect on Escherichia coli and Staphylococcus aureus. In summary, the coaxial electrospun membrane that we produced is expected to be used in clinical medicine, such as vascular stent membranes and bionic blood vessels.

9.
Biomed Mater ; 18(6)2023 09 11.
Article in English | MEDLINE | ID: mdl-37691568

ABSTRACT

In the past few decades, although tissue engineering has made significant progress and achieved many accomplishments, there are still some key problems that remain unsolved. One of the urgent research challenges in this field is how to prepare large-scale tissue engineering scaffolds with spatially complex structures. In this work, a sacrificial template process using sucrose as the sacrificial material and a gelatin/microbial transglutaminase mixed solution as the bio-scaffold material is proposed to fabricate a bio-scaffold with multi-level branching and spatially complex vascular network channels that mimic the structure and function of the human vascular network. To validate the feasibility of the fabrication process and the rationality of the process parameters, the morphological characteristics, connectivity of vascular network channels, shaping accuracy, and mechanical properties of the bio-scaffold were tested and analyzed. The results showed that the bio-scaffold fabricated using this process had a complete morphology and excellent connectivity. The diameter of the sucrose sacrificial template showed a linear relationship with the feeding speed, and the average diameter error rate between the sucrose sacrificial template and the vascular network channels inside the bio-scaffold was less than 8%. The mechanical properties of the bio-scaffold met the requirements for large-scale tissue defect repair. To evaluate the effect of the bio-scaffold on cell activity, human umbilical vein endothelial cells (HUVECs) were seeded into the vascular network channels of the bio-scaffold, and their attachment, growth, and proliferation on the surface of the vascular network channels were observed. To further assess the biocompatibility of the bio-scaffold, the bio-scaffold was implanted subcutaneously in the dorsal tissue of rats, and the tissue regeneration status was compared and analyzed through immunohistochemical analysis. The results showed that the vascular network channels within the bio-scaffold allowed uniform cell attachment, growth, with fewer dead cells and high cell viability. Moreover, clear cell attachment and growth were observed within the vascular network channels of the bio-scaffold after implantation in rats. These results indicate that the fabricated bio-scaffold meets the basic performance requirements for the repair and regeneration of large-scale tissue defects, providing a new approach for oxygen and nutrient transport in large-scale tissues and opening up new avenues for clinical applications.


Subject(s)
Gelatin , Oxygen , Humans , Animals , Rats , Cell Survival , Human Umbilical Vein Endothelial Cells , Sucrose
10.
J Tissue Eng ; 14: 20417314231187113, 2023.
Article in English | MEDLINE | ID: mdl-37464999

ABSTRACT

Three-dimensional (3D) bioprinting is a promising and rapidly evolving technology in the field of additive manufacturing. It enables the fabrication of living cellular constructs with complex architectures that are suitable for various biomedical applications, such as tissue engineering, disease modeling, drug screening, and precision regenerative medicine. The ultimate goal of bioprinting is to produce stable, anatomically-shaped, human-scale functional organs or tissue substitutes that can be implanted. Although various bioprinting techniques have emerged to develop customized tissue-engineering substitutes over the past decade, several challenges remain in fabricating volumetric tissue constructs with complex shapes and sizes and translating the printed products into clinical practice. Thus, it is crucial to develop a successful strategy for translating research outputs into clinical practice to address the current organ and tissue crises and improve patients' quality of life. This review article discusses the challenges of the existing bioprinting processes in preparing clinically relevant tissue substitutes. It further reviews various strategies and technical feasibility to overcome the challenges that limit the fabrication of volumetric biological constructs and their translational implications. Additionally, the article highlights exciting technological advances in the 3D bioprinting of anatomically shaped tissue substitutes and suggests future research and development directions. This review aims to provide readers with insight into the state-of-the-art 3D bioprinting techniques as powerful tools in engineering functional tissues and organs.

11.
Macromol Biosci ; 23(4): e2200521, 2023 04.
Article in English | MEDLINE | ID: mdl-36746773

ABSTRACT

Abdominal wall defects are a frequently occurring condition in surgical practice. The most important are material structure and biocompatibility. In this study, polylactic acid (PLA) mesh composited with a 3D printing of acellular dermal matrix (ADM) material is used to repair abdominal wall defects. The results show that the adhesion score of ADM/PLA composite scaffolds is smaller than PLA meshes. Immunohistochemical assessment reveals that the ADM/PLA composite scaffold can effectively reduce the inflammatory response at the contact surface between the meshes and the abdominal organs. And the ADM/PLA composite scaffold can effectively reduce the expression levels of the inflammation-related factors IL-6 and IL-10. In addition, the ADM/PLA composite scaffold repair is rich in the expression levels of tissue regeneration-related factors vascular endothelial growth factor and transforming growth factor ß. Thus, ADM/PLA composite scaffolds can effectively reduce surrounding inflammation to effectively promote the repair of abdominal wall defects.


Subject(s)
Abdominal Wall , Acellular Dermis , Rats , Animals , Abdominal Wall/surgery , Vascular Endothelial Growth Factor A , Polyesters , Printing, Three-Dimensional , Tissue Scaffolds/chemistry
12.
Biofabrication ; 15(2)2023 02 15.
Article in English | MEDLINE | ID: mdl-36735961

ABSTRACT

Three-dimensional microextrusion bioprinting has attracted great interest for fabrication of hierarchically structured, functional tissue substitutes with spatially defined cell distribution. Despite considerable progress, several significant limitations remain such as a lack of suitable bioinks which combine favorable cell response with high shape fidelity. Therefore, in this work a novel bioink of alginate-methylcellulose (AlgMC) blend functionalized with egg white (EW) was developed with the aim of solving this limitation. In this regard, a stepwise strategy was proposed to improve and examine the cell response in low-viscosity alginate inks (3%, w/v) with different EW concentrations, and in high-viscosity inks after gradual methylcellulose addition for enhancing printability. The rheological properties and printability of these cell-responsive bioinks were characterized to obtain an optimized formulation eliciting balanced physicochemical and biological properties for fabrication of volumetric scaffolds. The bioprinted AlgMC + EW constructs exhibited excellent shape fidelity while encapsulated human mesenchymal stem cells showed high post-printing viability as well as adhesion and spreading within the matrix. In a proof-of-concept experiment, the impact of these EW-mediated effects on osteogenesis of bioprinted primary human pre-osteoblasts (hOB) was evaluated. Results confirmed a high viability of hOB (93.7 ± 0.15%) post-fabrication in an EW-supported AlgMC bioink allowing cell adhesion, proliferation and migration. EW even promoted the expression of osteogenic genes, coding for bone sialoprotein (integrin binding sialoprotein/bone sialoprotein precursor (IBSP)) and osteocalcin (BGLAP) on mRNA level. To demonstrate the suitability of the novel ink for future fabrication of multi-zonal bone substitutes, AlgMC + EW was successfully co-printed together with a pasty calcium phosphate bone cement biomaterial ink to achieve a partly mineralized 3D volumetric environment with good cell viability and spreading. Along with the EW-mediated positive effects within bioprinted AlgMC-based scaffolds, this highlighted the promising potential of this novel ink for biofabrication of bone tissue substitutes in clinically relevant dimensions.


Subject(s)
Bioprinting , Bone Substitutes , Humans , Tissue Scaffolds/chemistry , Methylcellulose/chemistry , Bioprinting/methods , Alginates/chemistry , Egg White , Integrin-Binding Sialoprotein , Bone and Bones , Ink , Printing, Three-Dimensional , Tissue Engineering/methods
13.
Macromol Biosci ; 22(10): e2200208, 2022 10.
Article in English | MEDLINE | ID: mdl-35904133

ABSTRACT

Biocompatible hydrogels have been considered one of the most well-known and promising in various materials used in the fabrication of tissue-engineering scaffolds. Although considerable progress has been made in recent decades, many limitations remain, such as poor mechanical and degradation properties of biomaterials. In addition, vascularization of tissue-engineering scaffold is an enduring challenge, which limited the fabrication and application of scaffold with clinically relevant dimension. To cover these challenges, in this work, a novel nanocomposite interpenetrating polymer networks (IPN) hydrogel scaffold consists of methacrylated gelatin (GelMA), poly(vinyl alcohol) (PVA), and copper oxide nanoparticles (CuONPs) is fabricated by extrusion-based 3D printing. A series of physiochemical and biological characterizations of the nanocomposite GelMA/PVA scaffolds are performed. Results showed that the mechanical and degradation properties of the nanocomposite GelMA/PVA scaffolds are obviously improved compared to GelMA scaffolds with single network. In vitro cell experiments and chick embryo angiogenesis (CEA) assay confirmed good cytocompatibility of the fabricated scaffold and its potential to promote cell migration and angiogenesis. In conclusion, altogether the results demonstrated that GelMA/PVA IPN scaffolds modified with CuONPs have great potential for fabrication of volumetric scaffolds and promote angiogenesis during tissue growth and repair.


Subject(s)
Gelatin , Nanoparticles , Animals , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Chick Embryo , Copper/pharmacology , Gelatin/chemistry , Gelatin/pharmacology , Hydrogels/chemistry , Hydrogels/pharmacology , Methacrylates/chemistry , Nanoparticles/therapeutic use , Oxides , Polymers , Polyvinyl Alcohol/pharmacology , Printing, Three-Dimensional , Tissue Engineering/methods , Tissue Scaffolds/chemistry
14.
Macromol Biosci ; 22(6): e2100510, 2022 06.
Article in English | MEDLINE | ID: mdl-35471592

ABSTRACT

Hernia repair mesh is associated with a number of complications, including adhesions and limited mobility, due to insufficient mechanical strength and nonresorbability. Among them, visceral adhesions are one of the most serious complications of patch repair. In this study, a degradable patch with an antiadhesive layer is prepared for hernia repair by 3D printing and electrospinning techniques using polycaprolactone, polyvinyl alcohol, and soybean peptide (SP). The study into the physicochemical properties of the patch is found that it has adequate mechanical strength requirements (16 N cm-1 ) and large elongation at break, which are superior than commercial polypropylene patches. In vivo and in vitro experiments show that human umbilical vein endothelial cells proliferated well on composite patches, and showed excellent biocompatibility with the host and little adhesion through a rat abdominal wall defect model. In conclusion, the results of this study show that composite patch can effectively reduce the occurrence of adhesions, while the addition of SP in the patch further enhances its biocompatibility. It is believed that a regenerative biological patch with great potential in hernia repair provides a new strategy for the development of new biomimetic biodegradable patches.


Subject(s)
Herniorrhaphy , Surgical Mesh , Animals , Endothelial Cells , Herniorrhaphy/methods , Polypropylenes/chemistry , Rats , Tissue Adhesions
15.
Polymers (Basel) ; 14(4)2022 Feb 20.
Article in English | MEDLINE | ID: mdl-35215731

ABSTRACT

The most widely used 3D process, fused deposition modeling (FDM), has insufficient interlayer adhesion due to its layer-by-layer forming method. A support material is also essential for the hollow parts and cantilevers. Moreover, the polymer materials used have limited mechanical properties. These issues have restricted the application of FDM in high-performance fields. Continuous fiber-reinforced thermoplastic composites (CFRTPCs) have high mechanical properties and have recently become the focus of research in the field of 3D printing. This paper, using pipe parts as an example, proposes a hybrid of pure polymer (pure PLA used) and CFRTPC (flax fiber pre-impregnated filament) material to develop a printing method based on the outstanding mechanical properties of CFRTPC material. After studying the printing path planning algorithm, the CFRTPC filament is laid along the axial and radial directions on the surface of the polymer base to improve the printed parts' properties. The method feasibility and algorithm accuracy are verified through the development of five-axis printing equipment with a double nozzle. Through the printed sample's tensile, compression and bending tests, the results show that the tensile, compressive and bending properties of PLA pipe can be significantly enhanced by laying CFRTPC filament along the axial and radial directions of the pipe. To summarize, the introduction of CFRTPCs greatly improved the mechanical properties of the printed parts, and the implementation of our method provides an effective way to solve the defects of the FDM process.

16.
Macromol Biosci ; 22(4): e2100413, 2022 04.
Article in English | MEDLINE | ID: mdl-35043585

ABSTRACT

In recent years, 3D bioprinting has attracted broad research interest in biomedical engineering and clinical applications. However, there are two issues need to be solved urgently at present, the development of ink is the first pressing thing for 3D printing tissue engineering scaffold, other thing is the promotion of angiogenesis in the scaffold. Therefore, a gelatin/sodium alginate-based hydrogel with protein-rich is developed here, which is prepared by gelatin, sodium alginate, and soy protein/soy peptide powder. The prepared inks exhibit excellent shear-thinning behavior, which contribute to extrusion-based printing; also shown good crosslinking ability by calcium chloride. The macroporous composite scaffolds are printed by 3D printing using the developed ink and the physicochemical properties of the scaffolds are evaluated. Moreover, the cytocompatibility of printed scaffold is characterized by using human umbilical vein epidermal cells, results show that the scaffolds with soy protein and soy peptide powder can promote cell attach, spread, migration, and proliferation. The further research of chicken embryo allantoic membrane assay and animal experiment are carried, and results present that the scaffold can promote the growth of neo-vessels in the scaffold, which means the developed ink with soy protein and soy peptide powder has great potential for angiogenesis.


Subject(s)
Bioprinting , Gelatin , Alginates/chemistry , Alginates/pharmacology , Animals , Bioprinting/methods , Chick Embryo , Gelatin/chemistry , Gelatin/pharmacology , Hydrogels/chemistry , Hydrogels/pharmacology , Peptides/pharmacology , Powders , Printing, Three-Dimensional , Soybean Proteins/pharmacology , Tissue Engineering/methods , Tissue Scaffolds/chemistry
17.
Biotechnol Bioeng ; 119(1): 118-133, 2022 01.
Article in English | MEDLINE | ID: mdl-34617587

ABSTRACT

Three dimensional printable formulation of self-standing and vascular-supportive structures using multi-materials suitable for organ engineering is of great importance and highly challengeable, but, it could advance the 3D printing scenario from printable shape to functional unit of human body. In this study, the authors report a 3D printable formulation of such self-standing and vascular-supportive structures using an in-house formulated multi-material combination of albumen/alginate/gelatin-based hydrogel. The rheological properties and relaxation behavior of hydrogels were analyzed before the printing process. The suitability of the hydrogel in 3D printing of various customizable and self-standing structures, including a human ear model, was examined by extrusion-based 3D printing. The structural, mechanical, and physicochemical properties of the printed scaffolds were studied systematically. Results supported the 3D printability of the formulated hydrogel with self-standing structures, which are customizable to a specific need. In vitro cell experiment showed that the formulated hydrogel has excellent biocompatibility and vascular supportive behavior with the extent of endothelial sprout formation when tested with human umbilical vein endothelial cells. In conclusion, the present study demonstrated the suitability of the extrusion-based 3D printing technique for manufacturing complex shapes and structures using multi-materials with high fidelity, which have great potential in organ engineering.


Subject(s)
Endothelium, Vascular , Hydrogels/chemistry , Neovascularization, Physiologic , Printing, Three-Dimensional , Tissue Engineering/methods , Animals , Blood Vessels/cytology , Blood Vessels/drug effects , Cells, Cultured , Ear/blood supply , Endothelium, Vascular/cytology , Endothelium, Vascular/drug effects , Human Umbilical Vein Endothelial Cells , Humans , Neovascularization, Physiologic/drug effects , Neovascularization, Physiologic/physiology , Tissue Scaffolds/chemistry
18.
Nucleic Acids Res ; 50(D1): D303-D315, 2022 01 07.
Article in English | MEDLINE | ID: mdl-34792163

ABSTRACT

R-loops play versatile roles in many physiological and pathological processes, and are of great interest to scientists in multiple fields. However, controversy about their genomic localization and incomplete understanding of their regulatory network raise great challenges for R-loop research. Here, we present R-loopBase (https://rloopbase.nju.edu.cn) to tackle these pressing issues by systematic integration of genomics and literature data. First, based on 107 high-quality genome-wide R-loop mapping datasets generated by 11 different technologies, we present a reference set of human R-loop zones for high-confidence R-loop localization, and spot conservative genomic features associated with R-loop formation. Second, through literature mining and multi-omics analyses, we curate the most comprehensive list of R-loop regulatory proteins and their targeted R-loops in multiple species to date. These efforts help reveal a global regulatory network of R-loop dynamics and its potential links to the development of cancers and neurological diseases. Finally, we integrate billions of functional genomic annotations, and develop interactive interfaces to search, visualize, download and analyze R-loops and R-loop regulators in a well-annotated genomic context. R-loopBase allows all users, including those with little bioinformatics background to utilize these data for their own research. We anticipate R-loopBase will become a one-stop resource for the R-loop community.


Subject(s)
DNA/genetics , Genome , Neoplasms/genetics , Nervous System Diseases/genetics , R-Loop Structures , RNA/genetics , Software , Cell Line, Tumor , Chromosome Mapping , Computational Biology/methods , DNA/chemistry , DNA/metabolism , Databases, Nucleic Acid , Datasets as Topic , Gene Regulatory Networks , Genomic Instability , HEK293 Cells , Humans , Internet , Molecular Sequence Annotation , Neoplasms/metabolism , Neoplasms/pathology , Nervous System Diseases/metabolism , Nervous System Diseases/pathology , Protein Interaction Mapping/methods , RNA/chemistry , RNA/metabolism , Transcription, Genetic
20.
Macromol Biosci ; 21(6): e2000423, 2021 06.
Article in English | MEDLINE | ID: mdl-33870647

ABSTRACT

The meshes for hernia repair result in many problems that are related to complications including chronic pain and limited movement due to inadequate mechanical strength, non-absorbability, or low elasticity. In this study, degradable polylactic acid (PLA), synthetic thermoplastic polyurethane (TPU), and acellular dermal matrix (ADM) powders are combined to prepare a novel PLA/TPU/ADM mesh with three different topological structures (square, circular, and diamond) by 3D printing. The physicochemical properties and structural characteristics of mesh are studied, the results show that the diamond structure mesh with the pore size of 3 mm has sufficient elasticity and tensile strength, which provides the efficient mechanical strength required for hernia repair (16 N cm-1 ) and the value more than polypropylene(PP) mesh. Besides, in vitro and in vivo experiments demonstrate human umbilical vein endothelial cells could successfully proliferate on the PLA/TPU/ADM mesh whose biocompatibility with the host is shown using a rat model of abdominal wall defect. In conclusion, the results of this study demonstrate that the PLA/TPU/ADM mesh may be considered a good choice for hernia repair as its potential to overcome the elastic and strength challenges associated with a highly flexible abdominal wall, as well as its good biocompatibility.


Subject(s)
Acellular Dermis , Biocompatible Materials/pharmacology , Hernia, Abdominal/surgery , Herniorrhaphy/methods , Polyesters/pharmacology , Polyurethanes/pharmacology , Surgical Mesh , Abdominal Wall/surgery , Animals , Biocompatible Materials/chemistry , Cell Proliferation/drug effects , Elasticity , Herniorrhaphy/instrumentation , Human Umbilical Vein Endothelial Cells/cytology , Human Umbilical Vein Endothelial Cells/drug effects , Human Umbilical Vein Endothelial Cells/physiology , Humans , Male , Polyesters/chemistry , Polyurethanes/chemistry , Printing, Three-Dimensional , Rats , Rats, Sprague-Dawley , Tensile Strength
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