Scaffolds For Tissue Engineering Research Articles

Silk Foams with Metallic Nanoparticles as Scaffolds for Soft Tissue Regeneration

Tissue regeneration can be achieved by providing endogenous cells with a biomaterial scaffold that supports their adhesion and proliferation, as well as the synthesis and deposition of an extracellular matrix (ECM). In this work, silk fibroin protein foams were formed by lyophilization to generate tissue engineering scaffolds. Three types of medically relevant nanoparticles (NPs) (iron oxide, gold and silver) were added to this biomaterial to assess the ability of silk foams to be functionalized with these NPs. The structural and mechanical properties of the foams with and without the NPs were suitable for tissue support. The in vitro cytocompatibility of the scaffolds was confirmed according to the ISO 10993 guidelines. The biocompatibility of the scaffolds was investigated by assessing inflammation and endogenous cell colonization in a mouse subcutaneous model These in vivo experiments demonstrated a loss of acute inflammation and the absence of chronic inflammation in the grafted animals. The obtained results show that silk foams are good candidates for supporting soft tissue regeneration with the additional possibility of functionalization with NPs.

Advantages and prospects of cell derived decellularized extracellular matrix as tissue engineering scaffolds

To review the application of cell derived decellularized extracellular matrix (CDM) in tissue engineering. The literature related to the application of CDM in tissue engineering was extensively reviewed and analyzed. CDM is a mixture of cells and their secretory products obtained by culturing cells in vitro for a period of time, and then the mixture is treated by decellularization. Compared with tissue derived decellularized extracellular matrix (TDM), CDM can screen and utilize pathogen-free autologous cells, effectively avoiding the possible shortcomings of TDM, such as immune response and limited sources. In addition, by selecting the cell source, controlling the culture conditions, and selecting the template scaffold, the composition, structure, and mechanical properties of the scaffold can be controlled to obtain the desired scaffold. CDM retains the components and microstructure of extracellular matrix and has excellent biological functions, so it has become the focus of tissue engineering scaffolds. CDM is superior in the field of tissue engineering because of its outstanding adjustability, safety, and high bioactivity. With the continuous progress of technology, CDM stents suitable for clinical use are expected to continue to emerge.

Enhancing Regeneration and Functionality of Excitable Tissues via Integrating Bioelectronics and Bioengineered Constructs

Abstract The inherent complexities of excitable cardiac, nervous, and skeletal muscle tissues pose great challenges in constructing artificial counterparts with bioelectrical, structural, and mechanical properties that closely resemble their natural states. Recent advances have increasingly revealed the beneficial impact of bioelectrical microenvironments on cellular behaviors, functional tissue regeneration, and improved therapeutic outcomes for these excitable tissues. This review aims to unveil the mechanisms by which electrical microenvironments enhance the regeneration and functionality of excitable cells and tissues, considering both endogenous electrical cues from electroactive biomaterials and exogenous electrical stimuli from external electronic systems. We explore the synergistic effects of these electrical microenvironments, combined with structural and mechanical guidance, on the regeneration of excitable tissues using tissue engineering scaffolds. Additionally, the emergence of micro/nanoscale bioelectronics has significantly expanded the scope of this field, enabling intimate interactions between implantable bioelectronics and excitable tissues at the cellular, tissue, and organ levels. These interactions allow for precise data extraction and localized modulation of cell and tissue functionalities through intricately designed electronic components according to physiological needs. The integration of tissue engineering and bioelectronics holds the potential to achieve optimal outcomes, highlighting a growing trend in engineering living tissue construct-bioelectronic hybrids for restoring and monitoring damaged excitable tissues. Furthermore, we envision critical challenges in engineering the next generation of these hybrids, focusing on integrated fabrication strategies, the development of ionic conductive biomaterials, and their convergence with biosensors.

Biocomposite Scaffolds for Tissue Engineering: Materials, Fabrication Techniques and Future Directions

Tissue engineering is an interdisciplinary field that combines materials, methods, and biological molecules to engineer newly formed tissues to replace or restore functional organs. Biomaterials-based scaffolds play a crucial role in developing new tissue by interacting with human cells. Tissue engineering scaffolds with ideal characteristics, namely, nontoxicity, biodegradability, and appropriate mechanical and surface properties, are vital for tissue regeneration applications. However, current biocomposite scaffolds face significant limitations, particularly in achieving structural durability, controlled degradation rates, and effective cellular integration. These qualities are essential for maintaining long-term functionality in vivo. Although commonly utilized biomaterials can provide physical and chemical properties needed for tissue regeneration, inadequate biomimetic properties, as well as insufficient interactions of cells-scaffolds interaction, still need to be improved for the application of tissue engineering in vivo. It is impossible to achieve some essential features using a single material, so combining two or more materials may accomplish the requirements. In order to achieve a proper scaffold design, a suitable fabrication technique and combination of biomaterials with controlled micro or nanostructures are needed to achieve the proper biological responses. This review emphasizes advancements in scaffold durability, biocompatibility, and cellular responsiveness. It focuses on natural and synthetic polymer combinations and innovative fabrication techniques. Developing stimulus-responsive 3D scaffolds is critical, as these scaffolds enhance cell adhesion and promote functional tissue formation while maintaining structural integrity over time. This review also highlights the natural polymers, smart materials, and recent advanced techniques currently used to create emerging scaffolds for tissue regeneration applications.

Advancing biomedical applications: antioxidant and biocompatible cerium oxide nanoparticle-integrated poly-ε-caprolactone fibers.

Reactive oxygen species (ROS), which are expressed at high levels in many diseases, can be scavenged by cerium oxide nanoparticles (CeO2NPs). CeO2NPs can cause significant cytotoxicity when administered directly to cells, but this cytotoxicity can be reduced if CeO2NPs can be encapsulated in biocompatible polymers.In this study, CeO2NPs were synthesized using a one-stage process, then purified, characterized, and then encapsulated into an electrospun poly-ε-caprolactone (PCL) scaffold. The direct administration of CeO2NPs to RAW 264.7 Macrophages resulted in reduced ROS levels but lower cell viability. Conversely, the encapsulation of nanoceria in a PCL scaffold was shown to lower ROS levels and improve cell survival. The study demonstrated an effective technique for encapsulating nanoceria in PCL fiber and confirmed its biocompatibility and efficacy. This system has the potential to be utilized for developing tissue engineering scaffolds, targeted delivery of therapeutic CeO2NPs, wound healing, and other biomedical applications.&#xD.

Stem Cells: Innovations, Applications, and Future Directions

ABSTRACT Stem cells offer great promise in dentistry by regenerating critical oral tissues. Derived from sources such as dental pulp, periodontal ligament, and dental follicle, these cells can be pluripotent or multipotent and are capable of differentiating into various cell types, including odontoblasts and osteoblasts. This regenerative potential could transform treatments for dental conditions like periodontal disease and pulpitis. Advancing this field requires understanding stem cell differentiation and exploring tissue engineering and biomaterial scaffolds. Despite the potential, evolving legal and ethical issues shape the integration of these innovations. Research in dental stem cells represents a significant advance in regenerative medicine, promising to enhance dental treatments and patient care.

Eggshell‐Based Unconventional Biomaterials for Medical Applications

Eggshells are one of the most abundant byproducts of food processing waste. Each discarded eggshell represents a missed opportunity to convert a no‐cost waste material into a valuable product. Beyond their economic practicality and widespread availability, eggshells possess unique biological and chemical properties that support cell differentiation. Their composition includes biologically active compounds, essential trace elements, and collagenous and noncollagenous elements, mimicking the components of bones, teeth, and skin. Additionally, eggshells serve as a suitable precursor for synthesizing hydroxyapatite, calcium carbonate (CaCO3), and β‐tricalcium phosphate. Eggshells can be utilized on their own or as derived materials to produce regenerative biocomposite scaffolds for tissue engineering. These scaffolds often exhibit high porosity, excellent biocompatibility, degradability, and mechanical properties. Eggshells and their derivatives have also been employed as carriers for targeted drug delivery systems and in electrochemical biosensors. Eggshells serve as a versatile biomaterial, adept at not only addressing practical gaps but also bridging the divide between sophistication and ease of production. In this review, the chemical composition of eggshells and their numerous applications in hard and soft tissue regeneration, biomolecule delivery, and biosensor development are discussed highlighting their innovative and unconventional use as a natural biomaterial providing solutions for unmet clinical needs.

Determining the Permeability of Porous Bioceramic Scaffolds: Significance, Overview of Current Methods and Challenges Ahead

The “architectural suitability” of scaffolds for bone tissue engineering is commonly evaluated by assessing the pore volume and the mean pore size (or pore size distribution, if possible) and comparing these values with the reference ranges of human cancellous bone. However, these two parameters cannot precisely describe the complex architecture of bone scaffolds and just provide a preliminary comparative criterion. Permeability is suggested as a more comprehensive and significant parameter to characterize scaffold architecture and mass transport capability, being also related to bone in-growth and, thus, functional properties. However, assessing the permeability of bioactive ceramics and glass scaffolds is a complex task from both methodological and experimental viewpoints. After providing an overview of the fundamentals about porosity in scaffolds, this review explores the different experimental and numerical approaches used to determine the permeability of porous bioceramics, describing the methodologies used (pump-based, gravity-based, acoustic and computational methods) and highlighting advantages and limitations to overcome (e.g., reliability issues and need for better standardization of the experimental procedures).

Inorganic-Based Nanoparticles and Biomaterials as Biocompatible Scaffolds for Regenerative Medicine and Tissue Engineering: Current Advances and Trends of Development

Regenerative medicine amalgamates stem cell technology and tissue engineering strategies to replace tissues and organs damaged by injury, aging, ailment, and/or chronic conditions by leveraging the innate self-healing mechanism of the body. The term ‘regenerative medicine’ was coined by William A. Haseltine during a 1999 conference on Lake Como. Since its inception in 1968, the field has offered clinical benefits for the regeneration, repair, and restoration of bones, skin, cartilage, neural tissue, and the heart, as well as scaffold fabrication. The field of tissue engineering and regenerative medicine can vastly benefit from advancements in nanoscience and technology, particularly in the fabrication and application of inorganic-based nanoparticles and bionanomaterials. Due to the tunable intrinsic properties, i.e., size, topography, surface charge, and chemical stability, inorganic-based nanoparticles and biomaterials have surpassed traditional synthetic materials. Given the wide gamut of near-future applications of inorganic nanoparticles and biomaterials, this article gives an overview of the emerging roles in stem cell regenerative research, tissue engineering, artificial skin and cartilage regeneration, neural nerve injuries, 3D bioprinting, and development of new inorganic bio-scaffolds. The review also addresses the challenges related to the clinical application and tissue compatibility of inorganic nanoparticles and biomaterials, utilizing current state-of-the-art techniques.

3D printed sodium alginate/gelatin/tannic acid/calcium chloride scaffolds laden bone marrow mesenchymal stem cells to repair defective thyroid cartilage plate.

Due to the absence of blood vessels, cartilage exhibits extremely limited self-repair capacity. Currently, repairing laryngeal cartilage defects, resulting from conditions such as laryngeal tumors, injury, and congenital structural abnormalities, remains a significant challenge in the Department of Otolaryngology, Head and Neck Surgery. Previous research has often focused on enhancing the mechanical properties of synthetic materials. However, their low biological activity and weak cell adhesion necessitate compensatory measures. This study aims to capitalize on the advantages of natural materials in cartilage tissue engineering. Sodium alginate, gelatin, tannic acid, and calcium chloride were utilized to prepare bioinks through cross-linking for application in 3D printing cartilage scaffolds. Bone marrow mesenchymal stem cells with multidirectional differentiation potential were chosen as seed cells, with appropriate growth factors incorporated to promote their differentiation into cartilage during in vitro culture. The scaffold laden cells was subsequently implanted into rabbit thyroid cartilage plate defects at the appropriate time. HE staining, toluidine blue staining, Masson staining, and collagen type II staining were employed to assess cartilage defect repair at 4, 8, and 12 weeks, respectively. Results demonstrated that scaffolds made from natural materials could emulate the mechanical properties of fresh cartilage with commendable biocompatibility. Stained sections further confirmed the efficacy of the composite hydrogel scaffolds identified in this study in promoting rabbit thyroid cartilage plate restoration. In summary, this study successfully fabricated a natural material scaffold for rabbit laryngeal cartilage tissue engineering, thereby furnishing a new idea and experience for the clinical application of laryngeal cartilage defect reconstruction.

Application of Polylactic Acid in Clinical Medicine

Polylactic acid (PLA), a bio-based and biodegradable material, shows significant potential in environmental protection and clinical medicine. Derived from renewable resources, PLA's biodegradability reduces long-term environmental pollution by allowing it to decompose rapidly under specific conditions. This review explores PLA's applications in clinical medicine, emphasizing its mechanical properties, biocompatibility, and controlled degradation rates. The study covers PLA's extensive use in drug delivery systems, absorbable sutures, and tissue engineering scaffolds, highlighting its compatibility with human tissues and low immunogenicity. Research methods and designs, including in vitro and in vivo experiments, are discussed to evaluate PLA's efficacy and safety. The challenges of high production costs and specific degradation conditions are also addressed. Future research directions include developing new catalysts to improve synthesis efficiency and exploring renewable raw materials to reduce costs and environmental impact. As global awareness of sustainable development grows, the demand for PLA and other degradable plastics is expected to increase, expanding their applications in various fields. In conclusion, PLA offers substantial advantages in reducing reliance on fossil fuels and mitigating environmental pollution, while providing innovative solutions in the medical field. Technological advancements and increased production are anticipated to lower costs, making PLA more economically competitive and accelerating its application in both environmental protection and clinical medicine.

A Review on Advances and Challenges in Core-Shell Scaffolds for Bone Tissue Engineering: Design, Fabrication, and Clinical Translation.

This review explores core-shell scaffolds in bone tissue engineering, highlighting their osteoconductive and osteoinductive properties critical for bone growth and regeneration. Key design factors include material selection, porosity, mechanical strength, biodegradation kinetics, and bioactivity. Electrospun core-shell nanofibrous scaffolds demonstrate potential in delivering therapeutic agents and enhancing bone regeneration. Critical characterization techniques include structural, surface, chemical composition, mechanical, and degradation analyses. Scaling up production poses challenges, addressed by innovative electrospinning techniques. Future research focuses on regulatory and commercial considerations, while exploring advanced materials and fabrication methods to optimize scaffold performance for improved clinical outcomes.

Biowaste Transformation to Functional Materials: Structural Properties, Extraction Methods, Applications, and Challenges of Silk Sericin

AbstractThis review underscores the novelty of silk sericin, often regarded as a byproduct in silk production. Comprising approximately 30% of silk, sericin possesses valuable properties that have been largely overlooked in favor of silk fibroin. This work focuses on innovative extraction methods to convert sericin, typically considered waste, into a valuable resource. By examining these extraction techniques alongside diverse applications, the review aims to enhance the recognition and utilization of silk sericin in research and industry. Various extraction processes where the traditional methods, and some new techniques, are all discussed. In detail, the advantages, limitations, and strategy optimization associated with each extraction method are highlighted. For instance, silk sericin has shown promise as a wound treatment agent, a scaffold for tissue engineering, a carrier for drug delivery, and a biomaterial for regenerative medicine in the field of biomedical science due to its biocompatibility, biodegradability, and nontoxicity. Additionally, it also finds application in the cosmetic industry, where it is used in skincare products due to its moisturizing, antioxidant, and antiaging properties. Eventually, the challenges, limitations, and prospects of silk sericin are intensively discussed. This comprehensive review is expected to serve the growing body of knowledge surrounding silk sericin and foster further research and development of silk sericin‐related fields.

Tailoring the mechanical properties of macro-porous PVA hydrogels for biomedical applications

Polyvinyl alcohol (PVA) is a biocompatible biopolymer with superior dimensional and mechanical stability when compared to naturally available biomaterials such as collagen and gelatin. Furthermore, PVA in hydrogel form behaves non-linearly during mechanical loading, generating a response like soft biological tissues. Generally, PVA hydrogels are fabricated using freeze-thaw cycles (FTCs) and changing the number of FTCs gives control over its mechanical properties. Porosity of the hydrogel is another important factor which determines its mechanical properties and is also evident in biological soft tissues. Incorporating macro-pores in PVA hydrogels substantially reduces the stiffness of the material and can mimic some porous tissues such as lung, liver, bone marrow, kidneys, urethra and penile tissues (corpus cavernosa). Within this study, we developed macro-porous PVA hydrogels using the freeze-thaw process followed by particulate leaching of sacrificial 3D-printed and milled PVA (m-PVA) filler particles. This fabrication method enables control over the porosity in macro-porous PVA hydrogels, which is crucial not only for tuning mechanical properties but also for mimicking the structure of spongy tissues, such as liver tissue and corpus cavernosum in the penile tissue, for example. We investigated the level of porosity in the specimen using optical microscopy to understand the distribution of the pores and the pore size. The tunability of the mechanical properties of PVA hydrogels is, a key finding of this study and is achieved using three factors: (i) weight percentage of sacrificial fillers, (ii) number of FTCs and (iii) concentration of PVA. These macro-porous PVA specimens have wide ranging biomedical applications as biological soft tissue analogues, or tissue engineering scaffolds, where the PVA hydrogel can be tuned to match the mechanical properties of these soft biological tissues.

Investigation of Elaeocarpus ganitrus seed (EGs) powder as a sustainable composite biomaterial: Effects of particle size on the mechanical, frictional, and thermal properties for potential biomedical applications

This study explores the potential of Elaeocarpus ganitrus seed (EGs) powder as a sustainable composite biomaterial, focusing on its particle size effects on the mechanical, frictional, and thermal properties of composite materials for potential biomedical applications such as prosthetics and implants. Composite specimens were produced using the compression hot molding method, utilizing EG powder particles of varying sizes (120, 140, and 200-mesh sieving). The influence of EG powder particle size on key properties was systematically investigated. The findings reveal that reducing the particle size of EGs leads to a decrease in density and hardness of the composite, with the largest particle size (BP1) resulting in the highest density and hardness. Friction coefficient measurements indicated suitability for biomedical applications where surface interaction and wear resistance are critical, such as joint prosthetics. Thermal analysis showed that BP1 exhibited superior thermal stability, with a maximum decomposition temperature (Tmax) exceeding 375 °C. Differential scanning calorimetry identified significant differences in glass transition temperature (Tg) and crystallization temperature (Tc) across specimens. The composites demonstrated exceptional thermal performance, surpassing previous benchmarks for biomaterials in high-temperature environments. The mechanical and thermal characteristics of Specimen BP1—2.725 g/cm3 density, 74 Shore D hardness, 0.159 coefficient of friction, 93.3% total residual, 378.14 °C Tmax, 426.25 °C Tc, and 376.87 °C Tg—suggest its potential for biomedical applications requiring durability and thermal resilience, such as in orthopedic devices and tissue engineering scaffolds.

Identification of a Regenerative Protocol for Recellularizing Human Auricular Cartilage Scaffolds.

Utilizing biological scaffolds for cartilage tissue engineering is a promising tool for improving auricular reconstruction. Decellularized auricular scaffolds provide a means of regenerating cartilage for in vivo implantation, but identifying the ideal regenerative mix remains challenging. Human cadaver auricular cartilage was decellularized and recellularized with either auricular chondrocytes alone, auricular chondrocytes with adipose-derived stem cells, or both cells with platelet-rich plasma. Confirmation of decellularization and recellularization was done by hematoxylin and eosin staining. Extracellular matrix preservation and production were determined by Masson's trichrome, Alcian blue, and Verhoeff-van Gieson staining. Collagen II assessments were made using immunohistochemistry. Decellularization of cadaver auricular cartilage was confirmed by the absence of cells, reduction in glycosaminoglycans, and the preservation of collagen and elastin. Recellularization was more efficient when chondrocytes were seeded with adipose-derived stem cells, which was enhanced by adding platelet-rich plasma. Coculture with platelet-rich plasma yielded better total collagen (56% increase) and glycosaminoglycan (47% increase) induction. Moreover, when platelet-rich plasma was added, collagen II induction was significantly increased (42%; P < 0.05). We identified a regenerative protocol that included auricular chondrocytes, adipose-derived stem cells, and platelet-rich plasma, which stimulated chondrogenesis on decellularized auricular cartilage. This finding provides a model to explore cartilage formation and the potential for improving auricular and cartilage-based reconstruction.

Construction of Aligned Polycaprolactone/Poly(Glycerol Sebacate)/Polysulfone Nanofibrous Scaffolds for Tissue Engineering of the Ventricularis Layer of Heart Valves

Construction of Aligned Polycaprolactone/Poly(Glycerol Sebacate)/Polysulfone Nanofibrous Scaffolds for Tissue Engineering of the Ventricularis Layer of Heart Valves

A drug-loaded nano chitosan/hyaluronic acid hydrogel system as a cartilage tissue engineering scaffold for drug delivery

Cartilage lesions, especially osteoarthritis (OA), usually arise from aging, trauma, or obesity and require medical intervention due to the damaged site's inflammation and the cartilage tissue's poor self-healing capacity. This study aimed to prepare a drug-loaded nanoparticle hydrogel system with anti-inflammatory and chondroprotective effects to treat OA. First, hyaluronic acid (HA) was oxidized to create aldehyde functional groups and then cross-linked with adipic acid dihydrazide (ADH) to form a hydrogel. Next, chitosan nanoparticles (CS NPs) loaded with an anti-inflammatory molecule (fisetin) and or a chondrogenic and chondroprotective agent (kartogenin) were incorporated into the hyaluronan hydrogel to improve the release profile of the drug and increase its retention time in the joint cavity. Incorporating drug-loaded NPs into the hyaluronan hydrogel provided the hydrogel with controlled release features and improved properties. In addition, the real-time PCR (Polymerase chain reaction) results showed that the hyaluronan hydrogel containing both drug-loaded NPs performed better than either constituent alone on an in vitro model of OA. Finally, based on the results of in vitro evaluation, this drug-loaded nanoparticle hydrogel system can be a promising technique for treating OA by rapidly suppressing inflammation and supporting cartilage regeneration and requires further investigation in an animal model of OA. Meanwhile, this study investigated, for the first time, the effect of the simultaneous use of fisetin and kartogenin together with a nano CS/HA hydrogel system to treat OA.

Electrospun Polylactic Acid/Polyethylene Glycol/ Silicate‐Chlorinated Bioactive Glass Composite Scaffolds for Potential Bone Regeneration

ABSTRACTThe integration of bioglass with polymers in tissue engineering scaffolds holds promise for enhancing bone regeneration. This study explores the fabrication and characterization of composite scaffolds comprising polylactic acid (PLA)/polyethylene glycol (PEG) fibers incorporated with silicate‐chlorinated bioglasses (45S5 and 58S). Electrospinning was utilized to produce the scaffolds, followed by physical–chemical and in vitro evaluations. Scanning electron microscopy (SEM) revealed uniform fiber formation, with bioglass incorporation observed in the composite groups. Bioglass incorporation led to a significant reduction in fiber diameter. Thermogravimetric analysis (TGA) estimated bioglass content, with 58S exhibiting the highest incorporation. Contact angle measurements indicated enhanced hydrophilicity in bioglass‐containing groups. In vitro, bioactivity assessment in simulated body fluid (SBF) demonstrated apatite formation potential and the pH variance indicates a slightly alkaline to neutral condition. Cell culture studies revealed robust cellular adhesion and metabolic activity across all groups, with no cytotoxic effects observed. Overall, these findings suggest the potential of PLA/PEG bioglass composite scaffolds for bone tissue engineering applications.

Implementing Chicken Chorioallantoic Membrane (CAM) Assays for Validating Biomaterials in Tissue Engineering: Rationale and Methods.

Tissue engineering is a promising approach for generating or repairing living tissues. The development of innovative biomaterials for tissue engineering has the potential to address the unmet clinical needs in certain applications. However, before these biomaterials can be used in clinical settings, they must undergo preclinical testing to ensure safety and performance. The chicken chorioallantoic membrane (CAM) assay is a preferred screening tool for studying biocompatibility, angiogenesis, and inflammation induced by biomaterials owing to ethical and economic considerations. This CAM-based platform increased the throughput of biomaterial testing for tissue engineering before invivo testing. In this paper, we discuss the advantages of the CAM model. We also provided a step-by-step guide for implementing the CAM model in a research laboratory, along with tips and tricks for successfully running CAM assays. Finally, we present examples of biomaterials screened using CAM assays. CAM assay is a powerful invivo model for assessing the angiogenic potential of tissue-engineered scaffolds. This guide provides a framework for conducting the assay, but specific experimental conditions should be optimized based on the scaffold material and the research question.