Scaffold Material For Tissue Engineering Research Articles

Thick silk fibroin vascular graft: A promising tissue-engineered scaffold material for abdominal vein grafts in middle-sized mammals.

Abdominal vein replacement with synthetic tissue-engineered vascular grafts constructed from silk-based scaffold material has not been reported in middle-sized mammals. Fourteen canines that underwent caudal vena cava replacement with a silk fibroin (SF) vascular graft (15 mm long and 8 mm diameter) prepared with natural silk biocompatible thread were allocated to two groups, thin and thick SF groups, based on the graft wall thickness. The short-term patency rate and histologic reactions were compared. The patency rate at 2 weeks after replacement in the thin and thick SF groups was 50% and 88%, respectively (p = 0.04). CD31-positive endothelial cells covered the luminal surface of both groups at 4 weeks. The elastic modulus of the thick SF graft was significantly better than that of the thin SF graft (0.0210 and 0.0007 N/m2, p < 0.01). Roundness of thick SF groups (o = 0.8 mm) was better than thin SF (o = 2.0 mm). There was significant difference between the groups (p = 0.01). SF vascular grafts are a promising tissue-engineered scaffold material for abdominal venous system replacement in middle-sized mammals, with thick-walled grafts being superior to thin-walled grafts.

Osphronemus goramy scales-derived type 1 Collagen induces RUNX2 and Osteocalcin expression: An in vivo Study

Introduction: Alveolar bone defects need bone augmentation therapies by subtituting with bone material. Gourami (Osphronemus goramy) fish scale comprises type 1 collagen and it has been used as scaffolding material in bone tissue engineering. As alternative bone graft material, the scales have a big potency to promote osteogenesis in periodontal bone defect when autografts are not feasible. This study will analise Runx2 and Osteocalcin expression in wistar rat alveolar bone induced by type 1 collagen derived from gourami fish scale. Methods: 32 male Wistar rats were divided into four groups; control group—7 days (C7), treatment group—7 days (P7), control group—14 days (C14), and treatment group—14 days (P14). The left mandibular incisivus was extracted and the tooth socket was treated with 10mg collagen. The rats were euthanized (at day 7th and 14th) and immunohistochemistry was performed using monoclonal antibodies anti-RUNX2 and anti-osteocalcin. Results: After seven days and 14days, the expression of RUNX2 and osteocalcin in the treatment group increased significantly (p&lt;0.05) compared with the control group. Conclusion: Type 1 collagen from gourami (Osphronemus goramy) fish scales increases RUNX2 and osteocalcin expression as a bone growth marker.

Variation in the Composition Properties and its Effect on the Mechanical Properties of a cortical bone

Cortical bone is a composite material with varying mechanical properties as per the anatomical locations, orientations, etc. The relationship between bone cortical composition properties and compressive mechanical strength is important for selecting the right scaffold material. The findings show that the mineral content consisting mainly of hydroxyapatite crystals has a positive effect on the mechanical properties of the cortical bone, that is, an increase in the mineral content can increase the load capacity of the scaffold. According to this study, wet and dry densities equally impact the compressive strength and modulus of cortical bone. In addition, the presence of water degrades the quality of bone and reduces its ability to function, the variation in composition and its effect on mechanical properties must be considered when creating Scaffolds. The findings highlight the need to consider the properties of these composites when selecting scaffold materials for tissue engineering. The results of this study may help create biomimetic scaffolds with enhanced properties that support tissue regeneration and integration.

Applications of Engineered Skin Tissue for Cosmetic Component and Toxicology Detection.

The scale of the cosmetic market is increasing every day. There are many safety risks to cosmetics, but they benefit people at the same time. The skin can become red, swollen, itchy, chronically toxic, and senescent due to the misuse of cosmetics, triggering skin injuries, with contact dermatitis being the most common. Therefore, there is an urgent need for a system that can scientifically and rationally detect the composition and perform a toxicological assessment of cosmetic products. Traditional detection methods rely on instrumentation and method selection, which are less sensitive and more complex to perform. Engineered skin tissue has emerged with the advent of tissue engineering technology as an emerging bioengineering technology. The ideal engineered skin tissue is the basis for building good in vitro structures and physiological functions in this field. This review introduces the existing cosmetic testing and toxicological evaluation methods, the current development status, and the types and characteristics of engineered skin tissue. The application of engineered skin tissue in the field of cosmetic composition detection and toxicological evaluation, as well as the different types of tissue engineering scaffold materials and three-dimensional (3D) organoid preparation approaches, is highlighted in this review to provide methods and ideas for constructing the next engineered skin tissue for cosmetic raw material component analysis and toxicological evaluation.

Injectable Xenogeneic Dental Pulp Decellularized Extracellular Matrix Hydrogel Promotes Functional Dental Pulp Regeneration.

The present challenge in dental pulp tissue engineering scaffold materials lies in the development of tissue-specific scaffolds that are conducive to an optimal regenerative microenvironment and capable of accommodating intricate root canal systems. This study utilized porcine dental pulp to derive the decellularized extracellular matrix (dECM) via appropriate decellularization protocols. The resultant dECM was dissolved in an acid pepsin solution to form dECM hydrogels. The analysis encompassed evaluating the microstructure and rheological properties of dECM hydrogels and evaluated their biological properties, including in vitro cell viability, proliferation, migration, tube formation, odontogenic, and neurogenic differentiation. Gelatin methacrylate (GelMA) hydrogel served as the control. Subsequently, hydrogels were injected into treated dentin matrix tubes and transplanted subcutaneously into nude mice to regenerate dental pulp tissue in vivo. The results showed that dECM hydrogels exhibited exceptional injectability and responsiveness to physiological temperature. It supported the survival, odontogenic, and neurogenic differentiation of dental pulp stem cells in a 3D culture setting. Moreover, it exhibited a superior ability to promote cell migration and angiogenesis compared to GelMA hydrogel in vitro. Additionally, the dECM hydrogel demonstrated the capability to regenerate pulp-like tissue with abundant blood vessels and a fully formed odontoblast-like cell layer in vivo. These findings highlight the potential of porcine dental pulp dECM hydrogel as a specialized scaffold material for dental pulp regeneration.

Varying the Stiffness and Diffusivity of Rod-Shaped Microgels Independently through Their Molecular Building Blocks.

Microgels are water-swollen, crosslinked polymers that are widely used as colloidal building blocks in scaffold materials for tissue engineering and regenerative medicine. Microgels can be controlled in their stiffness, degree of swelling, and mesh size depending on their polymer architecture, crosslink density, and fabrication method-all of which influence their function and interaction with the environment. Currently, there is a lack of understanding of how the polymer composition influences the internal structure of soft microgels and how this morphology affects specific biomedical applications. In this report, we systematically vary the architecture and molar mass of polyethylene glycol-acrylate (PEG-Ac) precursors, as well as their concentration and combination, to gain insight in the different parameters that affect the internal structure of rod-shaped microgels. We characterize the mechanical properties and diffusivity, as well as the conversion of acrylate groups during photopolymerization, in both bulk hydrogels and microgels produced from the PEG-Ac precursors. Furthermore, we investigate cell-microgel interaction, and we observe improved cell spreading on microgels with more accessible RGD peptide and with a stiffness in a range of 20 kPa to 50 kPa lead to better cell growth.

Varying the Stiffness and Diffusivity of Rod‐Shaped Microgels Independently through Their Molecular Building Blocks

AbstractMicrogels are water‐swollen, crosslinked polymers that are widely used as colloidal building blocks in scaffold materials for tissue engineering and regenerative medicine. Microgels can be controlled in their stiffness, degree of swelling, and mesh size depending on their polymer architecture, crosslink density, and fabrication method—all of which influence their function and interaction with the environment. Currently, there is a lack of understanding of how the polymer composition influences the internal structure of soft microgels and how this morphology affects specific biomedical applications. In this report, we systematically vary the architecture and molar mass of polyethylene glycol‐acrylate (PEG‐Ac) precursors, as well as their concentration and combination, to gain insight in the different parameters that affect the internal structure of rod‐shaped microgels. We characterize the mechanical properties and diffusivity, as well as the conversion of acrylate groups during photopolymerization, in both bulk hydrogels and microgels produced from the PEG‐Ac precursors. Furthermore, we investigate cell‐microgel interaction, and we observe improved cell spreading on microgels with more accessible RGD peptide and with a stiffness in a range of 20 kPa to 50 kPa lead to better cell growth.

Application of gelatin microspheres in bone tissue engineering

Gelatin microspheres were discussed as a scaffold material for bone tissue engineering, with the advantages of its porosity, biodegradability, biocompatibility, and biosafety highlighted. This review discusses how bone regeneration is aided by the three fundamental components of bone tissue engineering-seed cells, bioactive substances, and scaffold materials-and how gelatin microspheres can be employed for in vitro seed cell cultivation to ensure efficient expansion. This review also points out that gelatin microspheres are advantageous as drug delivery systems because of their multifunctional nature, which slows drug release and improves overall effectiveness. Although gelatin microspheres are useful for bone tissue creation, the scaffolds that take into account their porous structure and mechanical characteristics might be difficult to be created. This review then discusses typical techniques for creating gelatin microspheres, their recent application in bone tissue engineering, as well as possible future research directions.

Application of Decellularized Adipose Matrix as a Bioscaffold in Different Tissue Engineering.

With the development of tissue engineering, the application of decellularized adipose matrix as scaffold material in tissue engineering has been intensively explored due to its wide source and excellent potential in tissue regeneration. Decellularized adipose matrix is a promising candidate for adipose tissue regeneration, while modification of decellularized adipose matrix scaffold can also allow it to transcend the limitations of adipose tissue source properties and applied to other tissue engineering fields, including cartilage and bone tissue engineering, neural tissue engineering, and skin tissue engineering. In this review, we summarized the development of the applications of decellularized adipose matrix in different tissue engineering and present future perspectives.Level of Evidence III This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Preparation and properties of silica/hydroxyapatite whiskers porous ceramics scaffold

To investigate the preparation and properties of the novel silica (SiO 2)/hydroxyapatite (HAP) whiskers porous ceramics scaffold. The HAP whiskers were modified by the SiO 2 microspheres using the Stöber method. Three types of SiO 2/HAP whiskers were fabricated under different factors (for the No.1 samples, the content of tetraethoxysilane, stirring time, calcination temperature, and soaking time were 10 mL, 12 hours, 560℃, and 0.5 hours, respectively; and in the No.2 samples, those were 15 mL, 24 hours, 650℃, and 2 hours, respectively; while those in the No.3 samples were 20 mL, 48 hours, 750℃, and 4 hours, respectively). The phase and morphology of the self-made HAP whisker and 3 types of SiO 2/HAP whiskers were detected by the X-ray diffraction analysis and scanning electron microscopy. Taken the self-made HAP whisker and 3 types of SiO 2/HAP whiskers as raw materials, various porous ceramic materials were prepared using the mechanical foaming method combined with extrusion molding method, and the low-temperature heat treatment. The pore structure of porous ceramics was observed by scanning electron microscopy. Its porosity and pore size distribution were measured. And further the axial compressive strength was measured, and the biodegradability was detected by simulated body fluid. Cell counting kit 8 method was used to conduct cytotoxicity experiments on the extract of porous ceramics. The SiO 2 microspheres modified HAP whiskers and its porous ceramic materials were prepared successfully, respectively. In the SiO 2/HAP whiskers, the amorphous SiO 2 microspheres with a diameter of 200 nm, uniform distribution and good adhesion were attached to the surface of the whiskers, and the number of microspheres was controllable. The apparent porosity of the porous ceramic scaffold was about 78%, and its pore structure was composed of neatly arranged longitudinal through-holes and a large number of micro/nano through-holes. Compared with HAP whisker porous ceramic, the axial compressive strength of the SiO 2/HAP whisker porous ceramics could reach 1.0 MPa, which increased the strength by nearly 4 times. Among them, the axial compressive strength of the No.2 SiO 2/HAP whisker porous ceramic was the highest. The SiO 2 microspheres attached to the surface of the whiskers could provide sites for the deposition of apatite. With the content of SiO 2 microspheres increased, the deposition rate of apatite accelerated. The cytotoxicity level of the prepared porous ceramics ranged from 0 to 1, without cytotoxicity. SiO 2/HAP whisker porous ceramics have good biological activity, high porosity, three-dimensional complex pore structure, good axial compressive strength, and no cytotoxicity, which make it a promising scaffold material for bone tissue engineering.

Scaffold fabrication for tissue engineering based on radiation copolymerization of polymer blends: (I) Zein/poly (vinyl butyral) blends

AbstractThe main objective of this work is to fabricate scaffold material for tissue engineering and using Vero (monkey kidney cells)/Paulownia tomentosa cells as model cells. For this objective, copolymer blends of poly(vinyl butyral) (PVB) and Zein, the main constituent, have been fabricated as thin films. Fourier‐transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimeter (DSC), and x‐ray diffraction (XRD) were used to characterize the copolymer blends. The findings showed that Zein component degradation caused the gel fraction percentage to decrease with higher irradiation doses. Zein's thermal characteristics are also decreased by the addition of PVB polymer, but they are improved by irradiation to 10 kGy through promoting phase adhesion and the generation of free radicals at boundary surfaces. Vero (Monkey kidney) cells proliferate more rapidly in the blend Zein/PVB (85/15%) irradiated to 45 kGy than in the unirradiated one. On the other hand, the Paulownia tomentosa cells proliferation was died.Highlights Copolymer blends of Zein and PVB were prepared by gamma irradiation. The copolymers were fabricated as scaffold material for tissue engineering using monkey kidney cells. PVB and Zein copolymer were characterized by FT‐IR, SEM, DSC, and XRD. The Zein/PVB (85/15%)—45 kGy has monkey kidney cells proliferation better than unirradiated one.

Sudan Black B Pretreatment to Suppress Autofluorescence in Silk Fibroin Scaffolds.

Natural polymers are extensively utilized as scaffold materials in tissue engineering and 3D disease modeling due to their general features of cytocompatibility, biodegradability, and ability to mimic the architecture and mechanical properties of the native tissue. A major limitation of many polymeric scaffolds is their autofluorescence under common imaging methods. This autofluorescence, a particular challenge with silk fibroin materials, can interfere with the visualization of fluorescently labeled cells and proteins grown on or in these scaffolds, limiting the assessment of outcomes. Here, Sudan Black B (SBB) was successfully used prefixation prior to cell seeding, in various silk matrices and 3D model systems to quench silk autofluorescence for live cell imaging. SBB was also trialed postfixation in silk hydrogels. We validated that multiple silk scaffolds pretreated with SBB (hexafluoro-2-propanol-silk scaffolds, salt-leached sponges, gel-spun catheters, and sponge-gel composite scaffolds) cultured with fibroblasts, adipose tissue, neural cells, and myoblasts demonstrated improved image resolution when compared to the nonpretreated scaffolds, while also maintaining normal cell behavior (attachment, growth, proliferation, differentiation). SBB pretreatment of silk scaffolds is an option for scaffold systems that require autofluorescence suppression.

Effect of static tensile stress on enzymatic degradation of poly(glycerol sebacate).

Poly(glycerol sebacate) (PGS) is an excellent scaffold material in tissue engineering due to good biocompatibility and tunable mechanical properties. The degradation properties of PGS have been primarily explored in static phosphate buffer solution or enzyme solution. It is vital to understand how the tensile stress affect the degradation rate. In this study, PGS was synthetized by melt polycondensation and its properties were characterized. Then an in vitro degradation device which could provide different constant tensile stresses was carefully designed and established, and the enzymatic degradation of PGS was tested under 0-150 kPa at 37°C. It was found that holes of PGS surface arranged almost parallel to each other and perpendicular to the direction of tensile stresses at 100 kPa and 150 kPa after 2-4 days degradation. After 8 days degradation, the ultimate tensile strength (UTS) of PGS at 150 kPa was 0.28 MPa and the elastic modulus was 1.11 MPa, while the UTS of PGS was 0.44 MPa and the elastic modulus was 1.63 MPa before degradation, both of them have significant differences. Hence, the tensile stress and degradation time were proportional to the appear time and size of holes, leading to the decrease of mass loss, UTS and elastic modulus. The relationship between stress and PGS degradation rates was quantitatively described through our degradation experiments, providing guidance for suitable PGS applications in the future.

Tunable Mesoscopic Collagen Island Architectures Modulate Stem Cell Behavior (Adv. Mater. 16/2023)

Tissue Engineering In article number 2207882, Ryan Y. Nguyen, Michael Mak, and co-workers report the fabrication of collagen I hydrogels with topology that mimics complex extracellular matrix architectures in tissues. The generated mesoscopic features, termed collagen islands, are tunable and modulate bulk hydrogel mechanical properties. Collagen islands can modulate stem cell behavior and differentiation. This hydrogel fabrication method provides novel scaffolding materials for tissue engineering.

Dendritic Polymers in Tissue Engineering: Contributions of PAMAM, PPI PEG and PEI to Injury Restoration and Bioactive Scaffold Evolution

The capability of radially polymerized bio-dendrimers and hyperbranched polymers for medical applications is well established. Perhaps the most important implementations are those that involve interactions with the regenerative mechanisms of cells. In general, they are non-toxic or exhibit very low toxicity. Thus, they allow unhindered and, in many cases, faster cell proliferation, a property that renders them ideal materials for tissue engineering scaffolds. Their resemblance to proteins permits the synthesis of derivatives that mimic collagen and elastin or are capable of biomimetic hydroxy apatite production. Due to their distinctive architecture (core, internal branches, terminal groups), dendritic polymers may play many roles. The internal cavities may host cell differentiation genes and antimicrobial protection drugs. Suitable terminal groups may modify the surface chemistry of cells and modulate the external membrane charge promoting cell adhesion and tissue assembly. They may also induce polymer cross-linking for healing implementation in the eyes, skin, and internal organ wounds. The review highlights all the different categories of hard and soft tissues that may be remediated with their contribution. The reader will also be exposed to the incorporation of methods for establishment of biomaterials, functionalization strategies, and the synthetic paths for organizing assemblies from biocompatible building blocks and natural metabolites.

Basic fibroblast growth factor/chitosan derivatives/collagen composite thermosensitive hydrogel promotes perio-dontal tissue regeneration in rats.

To investigate the feasibility of different thermosensitive composite hydrogels from chitosan derivatives as scaffold materials for periodontal tissue engineering. Three chitosan derivatives with different biological characteristics were prepared, namely, sulfonated chitosan (SCS), phosphorylated chitosan (PCS), and phosphorylated sulfonated chitosan (PSCS). Three thermosensitive composite hydrogels were constructed using basic fibroblast growth factor (bFGF), the chitosan derivatives, and collagen. Twenty male Wistar rats were randomly divided into control group, blank group, bFGF/SCS/collagen composite thermosensitive hydrogel group, bFGF/PCS/collagen compo-site thermosensitive hydrogel group, and bFGF/PSCS/collagen composite thermosensitive hydrogel group. Then, three-wall intrabony defects were established. The defects were treated with the different kinds of thermosensitive composite hydrogels. After 6 weeks of surgery, the animals were killed, and specimens were collected. Then, gross observation, hematoxylin-eosin staining, and Masson staining were performed. The bFGF/chitosan derivatives/collagen composite thermosensitive hydrogel groups and the control group had statistical differences in the relative alveolar bone height, relative epithelial down growth and grading count score of periodontal tissue regeneration (P<0.05). bFGF/chitosan derivatives/collagen composite thermosensitive hydrogels have good application prospects in periodontal tissue engineering.

Applications and Future Aspects of 4D Printed Biopolymeric Scaffold Materials in Tissue Engineering: A Systematic Literature Review

The emergence of smart materials (stimulus-responsive materials) and cells enables 4D printing to enhance printed structures dynamically. By undergoing controlled morphological changes, engineered tissues may be made using these dynamic scaffolds. This article provides an overview of the use of stimuli-responsive biomaterials in tissue engineering and several 4D printing methodologies based on the functional change of printed objects. This review also goes through the existing and future prospects for using 4D printing in bone tissue engineering and the limitations in this field. Using a variety of stimuli-responsive biomaterials and 4D printing techniques, the form or function of these objects might evolve. These novel technologies have the potential to meet unmet medical needs, as shown by a recent review that summarised the use of 4D printing in bone tissue engineering. This current review is about the potential of this cutting-edge technology for tissue engineering in the biomedical area by delving further into the ongoing conversations regarding future issues and perspectives.

Electrospinning Inorganic Nanomaterials to Fabricate Bionanocomposites for Soft and Hard Tissue Repair

Tissue engineering (TE) has attracted the widespread attention of the research community as a method of producing patient-specific tissue constructs for the repair and replacement of injured tissues. To date, different types of scaffold materials have been developed for various tissues and organs. The choice of scaffold material should take into consideration whether the mechanical properties, biodegradability, biocompatibility, and bioresorbability meet the physiological properties of the tissues. Owing to their broad range of physico-chemical properties, inorganic materials can induce a series of biological responses as scaffold fillers, which render them a good alternative to scaffold materials for tissue engineering (TE). While it is of worth to further explore mechanistic insight into the use of inorganic nanomaterials for tissue repair, in this review, we mainly focused on the utilization forms and strategies for fabricating electrospun membranes containing inorganic components based on electrospinning technology. A particular emphasis has been placed on the biological advantages of incorporating inorganic materials along with organic materials as scaffold constituents for tissue repair. As well as widely exploited natural and synthetic polymers, inorganic nanomaterials offer an enticing platform to further modulate the properties of composite scaffolds, which may help further broaden the application prospect of scaffolds for TE.

Silk Fibroin Combined with Electrospinning as a Promising Strategy for Tissue Regeneration.

The development of tissue engineering scaffolds is of great significance for the repair and regeneration of damaged tissues and organs. Silk fibroin (SF) is a natural protein polymer with good biocompatibility, biodegradability, excellent physical and mechanical properties and processability, making it an ideal universal tissue engineering scaffold material. Nanofibers prepared by electrospinning have attracted extensive attention in the field of tissue engineering due to their excellent mechanical properties, high specific surface area, and similar morphology as to extracellular matrix (ECM). The combination of silk fibroin and electrospinning is a promising strategy for the preparation of tissue engineering scaffolds. In this review, the research progress of electrospun silk fibroin nanofibers in the regeneration of skin, vascular, bone, neural, tendons, cardiac, periodontal, ocular and other tissues is discussed in detail.

New skin tissue engineering scaffold with sulfated silk fibroin/chitosan/hydroxyapatite and its application

Repairing skin wounds has always been challenging in clinical practice. The new skin tissue engineering scaffold provides innovative ways to address these challenges with a good chance of success because of its stable mechanical properties, biodegradability, and antibacterial properties. This paper presents the fabrication and evaluation of a three-dimensional composite scaffold made with sulfated silk fibroin, chitosan, and hydroxyapatite (SSF/CS/HAP). An electron microscope shows that the scaffold has an aperture of 15–20 μm, while an absorption performance test shows that its expansion index reaches 779%. The co-culture of L929 cells and the CCK-8 experiments demonstrated good cell compatibility and low scaffold cytotoxicity, respectively. Meanwhile, in vivo experiments demonstrate that rats with SSF/CS/HAP scaffold-treated neck wounds heal faster. In the wound skin tissue of the SSF/CS/HAP scaffold group, immunohistochemistry indicates a more rapid and mature development of hair follicles. This study successfully developed a novel skin tissue engineering scaffold material with high moisture retention, high tissue compatibility, and low cytotoxicity, demonstrating its ability to improve wound repair with promising potential for tissue engineering applications.