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The study addresses the challenge of temperature sensitivity in pristine gelatin hydrogels, widely used in biomedical applications due to their biocompatibility, low cost, and cell adhesion properties. Traditional gelatin hydrogels dissolve at physiological temperatures, limiting their utility. Here, we introduce a novel method for creating stable hydrogels at 37 °C using pristine gelatin through photopolymerization without requiring chemical modifications. This approach enhances consistency and simplifies production and functionalization of the gelatin with bioactive molecules. The stabilization mechanism involves the partial retention of the triple-helix structure of gelatin below 25 °C, which provides specific crosslinking sites. Upon activation by visible light, ruthenium (Ru) acts as a photosensitizer that generates sulphate radicals from sodium persulphate (SPS), inducing covalent bonding between tyrosine residues and "locking" the triple-helix conformation. The primary focus of this work is the characterization of the mechanical properties, swelling ratio, and biocompatibility of the photopolymerized gelatin hydrogels. Notably, these hydrogels supported better cell viability and elongation in normal human dermal fibroblasts (NHDFs) compared to GelMA, and similar performance was observed for human pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). As a proof of concept for functionalization, gelatin was modified with selenous acid (GelSe), which demonstrated antioxidant and antimicrobial capacities, particularly against E. coli and S. aureus. These results suggest that pristine gelatin hydrogels, enhanced through this new photopolymerization method and functionalized with bioactive molecules, hold potential for advancing regenerative medicine and tissue engineering by providing robust, biocompatible scaffolds for cell culture and therapeutic applications. [ABSTRACT FROM AUTHOR]

Purpose: To compare bone substitutes composed of glycated collagen with synthetic micro-sized (1 to 10 µm) hydroxyapatite (OB) vs non-cross-linked collagen matrix with large-particle (250 to 1,000 µm) bovine-derived hydroxyapatite (BOC). Materials and Methods: The P1 to P4 premolars were bilaterally extracted from the mandibles of 19 Beagle dogs. After 21 days, osteotomies were created in each dog that received OB or BOC and were covered with a collagen membrane or were left untreated. The animals were randomly divided into three groups based on sacrifice time (4, 12, or 24 weeks). The right and left hemimandibles were trimmed to facilitate imaging and histology, and all tissues were placed in 10% neutral-buffered formalin. Microcomputed tomography (MicroCT 40 Scanner, Scanco) was used to analyze bone sections. Bone volume, residual material volume, and bone mineral density were determined for each treatment site (OB and BOC) based on a volume of interest that encompassed the original defect. Additionally, blinded histopathologic assessment (based on the ISO 10993-6 scoring system) and histomorphometry were performed on sections ground to < 100 µm thick and stained with Stevenel's blue. Results: No clinical side effects were noted. No statistical differences were observed for OB vs BOC regarding the mineral volume percentage. Compared to OB, BOC had significantly higher mean mineralization densities at 12 weeks (P < .01), but this difference did not extend to 24 weeks. For residual grafting material, bone maturation, alveolar ridge restoration, and inflammatory response, OB showed a residual amount of bone graft and no statistical differences compared to BOC. Conclusion: Both OB and BOC represent valid treatment options for critically sized bone defects. Both bone fillers outperformed the sham-operated, ungrafted (empty) control, demonstrating statistically improved bone growth and ridge restoration. [ABSTRACT FROM AUTHOR]

Performing soft tissue augmentation (STA) at implant sites to improve esthetics, patient satisfaction, and peri-implant health is common. Several soft tissue grafting materials can be used to increase soft tissue thickness at the second-stage surgery, including human dermal matrices and xenogeneic collagen scaffolds. This study assessed and compared the volumetric outcomes, from second-stage surgery to crown delivery, around implants that received STA with a xenogeneic cross-linked collagen scaffold (XCCS) vs nonaugmented implant sites. Thirty-one patients (31 implant sites) completed the study. Intraoral digital scans were taken at the second stage and prior to crown delivery, and the STL files were imported in an image-analysis software to assess volumetric changes. XCCS-augmented implants showed significantly greater volumetric changes compared to control sites, which showed volume loss. The mean thickness of the XCCS-augmented area was 0.73 mm. There was no difference in patient-reported esthetic evaluations between groups. STA with XCCS provided significantly greater volumetric outcomes compared to nonaugmented sites. Further studies are needed to evaluate the long-term behavior of the augmented peri-implant mucosa and the effects of STA on peri-implant health. [ABSTRACT FROM AUTHOR]

BACKGROUND: Gradient artificial bone repair scaffolds can mimic unique anatomical features in musculoskeletal tissues, showing great potential for repairing injured musculoskeletal tissues. OBJECTIVE: To review the latest research advances in gradient artificial bone repair scaffolds for tissue engineering in the musculoskeletal system and describe their advantages and fabrication strategies. METHODS: The first author of the article searched the Web of Science and PubMed databases for articles published from 2000 to 2023 with search terms "gradient, bone regeneration, scaffold". Finally, 76 papers were analyzed and summarized after the screening. RESULTS AND CONCLUSION: (1) As an important means of efficient and high-quality repair of skeletal system tissues, gradient artificial bone repair scaffolds are currently designed bionically for the natural gradient characteristics of bone tissue, bone-cartilage, and tendon-bone tissue. These scaffolds can mimic the extracellular matrix of native tissues to a certain extent in terms of structure and composition, thus promoting cell adhesion, migration, proliferation, differentiation, and regenerative recovery of damaged tissues to their native state. (2) Advanced manufacturing technology provides more possibilities for gradient artificial bone repair scaffold preparation: Gradient electrospun fiber scaffolds constructed by spatially differentiated fiber arrangement and loading of biologically active substances have been developed; gradient 3D printed scaffolds fabricated by layered stacking, graded porosity, and bio-3D printing technology; gradient hydrogel scaffolds fabricated by in-situ layered injections, simple layer-by-layer stacking, and freeze-drying method; and in addition, there are also scaffolds made by other modalities or multi-method coupling. These scaffolds have demonstrated good biocompatibility in vitro experiments, were able to accelerate tissue regeneration in small animal tests, and were observed to have significantly improved histological structure. (3) The currently developed gradient artificial bone repair scaffolds have problems such as mismatch of gradient scales, unclear material-tissue interactions, and side effects caused by degradation products, which need to be further optimized by combining the strengths of related disciplines and clinical needs in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: It has been confirmed that the mixing of decellularized matrix and polymer electrospinning can not only improve the structural properties of fibers, but also preserve the biological decellularized of decellularized matrix. However, there is no relevant report on the preparation of skin tissue engineering scaffolds by electrospinning polyurethane and decellularized skin matrix. OBJECTIVE: To investigate the reparative effect of a decellularized skin matrix/polyurethane blended fibrous scaffold on rat skin defects. METHODS: Polyurethane electrospun fibrous scaffold and decellularized skin matrix/polyurethane blended fibrous scaffold were fabricated using the electrospinning technique. The fiber structure was observed under scanning electron microscope. Rat adipose mesenchymal stem cells were inoculated on two kinds of scaffolds respectively. The morphology of the scaffolds was observed under scanning electron microscope. Three full-thickness skin defects of 1 cm×1 cm were fabricated on the back of 10 SD rats. Polyurethane electrospun fibrous scaffolds (control group) and decellularized skin matrix/polyurethane blended fibrous scaffolds (experimental group) were implanted in two of the defects, and no material was implanted in the remaining defects (blank control group). The skin wound healing was observed at 1, 2, and 3 weeks after operation. At 3 weeks after implantation, the wound was stained with hematoxylin and eosin and the scar area was calculated. RESULTS AND CONCLUSION: (1) Under scanning electron microscope, the two kinds of electrospun fibers were reticulated, and the rat adipose mesenchymal stem cells attached to the fibers on the two kinds of scaffolds, and the adhesion was good. (2) With the extension of the postoperative time, the skin wounds of each group gradually healed. By week 3 after the operation, the skin wounds of the experimental group and the control group were basically healed, and small ulcers could be seen on the wounds of the blank control group. Hematoxylin-eosin staining of skin wounds showed that the epidermal coverage of the wound was basically complete in the control group and the experimental group, and fibroblast growth and inflammatory cell infiltration could be seen in the dermis. In addition, the collagen fibers of the wound in the experimental group were abundant and arranged in a regular order, basically parallel to the epidermal surface. The wound epidermis of blank control group was still defective. The scar area of the experimental group was smaller than that of the other two groups (P < 0.05, P < 0.01). (3) These results indicate that the decellularized skin matrix/polyurethane blended fibrous scaffold can effectively repair full-thickness skin defects and improve scar formation in rats [ABSTRACT FROM AUTHOR]

BACKGROUND: Polylactic acid (PLA) has good biocompatibility and a controllable degradation rate and is currently widely used in biomedical engineering. However, PLA has shortcomings such as low mechanical strength and insufficient biological activity, which limits its further application in bone tissue engineering. OBJECTIVE: To construct polylactic acid/polydopamine/tantalum (PLA/PDA/Ta) bone tissue engineering scaffolds, and explore their biosafety and in vitro osteogenesis. METHODS: A PLA scaffold with a porous structure was prepared through liquid crystal display light-curing technology. PLA/PDA scaffolds and PLA/PDA/Ta scaffolds were prepared by soaking PLA scaffolds in dopamine solution and dopamine-tantalum nanoparticle solution, respectively. The microstructure and water contact angle of scaffolds were characterized. MC3T3-E1 cells were co-cultured with PLA, PLA/PDA, and PLA/PDA/Ta scaffolds, respectively, and CCK-8 assay and live/dead cell staining were performed. After osteogenic differentiation, alkaline phosphatase, alizarin red staining, and osteogenic gene detection were performed. RESULTS AND CONCLUSION: (1) The scanning electron microscope results exhibited that the three kinds of prepared scaffolds had an interconnected porous three-dimensional structure, and the average pore diameter was 200 μm. The water contact angle of PLA/PDA/Ta scaffolds was lower than that of PLA and PLA/ PDA scaffolds (P < 0.05). (2) CCK-8 assay showed that compared with PLA and PLA/PDA scaffolds, PLA/PDA/Ta scaffolds could promote cell proliferation (P < 0.05). Live/dead cell staining showed good cell proliferation in the three groups. (3) Alkaline phosphatase and alizarin red staining showed that compared with PLA and PLA/PDA scaffolds, PLA/PDA/Ta scaffolds could promote the expression of alkaline phosphatase and the formation of mineralized nodules. RT-qPCR showed that compared with PLA and PLA/PDA scaffolds, PLA/PDA/Ta scaffolds could enhance the mRNA expression of cell bone morphogenetic protein, Runx- 2, and type I collagen (P < 0.05, P < 0.01). (4) The results showed that the PLA/PDA/Ta scaffold had excellent osteogenic activity and the ability to promote cell proliferation. [ABSTRACT FROM AUTHOR]

Poly-ether-ether-ketone (PEEK) is a high strength polymer with strong potential for medical use, especially for bone implants. In this research, a novel method of making biomimetic porous PEEK scaffolds is developed. PEEK and polyethersulfone (PES) are blended at a proper ratio to generate a co-continuous phase structure. With solid-state foaming, PES is efficiently removed by leaching to yield interconnected porous PEEK scaffolds. The pore size and pore gradient of the PEEK scaffolds can be easily controlled by controlling the annealing time and temperature of the PEEK/PES blend. This study presents the conditions of the proposed fabrication process and compares the fabricated porous PEEK scaffolds with those fabricated using other methods. It is shown that the structural morphology and mechanical properties of the fabricated porous PEEK is generally comparable to those of trabecular bones, suggesting these scaffolds could be excellent candidates for bone implant applications. [ABSTRACT FROM AUTHOR]

Poly (3-hydroxybutyrate) and poly (ethylene glycol) are frequently used as materials for designing scaffolds in tissue engineering. This work aimed the production of P3HB-PEG scaffolds in different weight ratio of PEG using electrospinning and characterized. Samples also were examined for rabbit chondrocyte cell assay. 5 wt% of PEG decreased the nanofiber diameter with more uniformity and enhanced hydrophilicity. The biodegradation rate increased while the mechanical features tended to decrease. In vitro tests showed good chondrocyte cell viability and adhesion. These results manifested that electrospun the P3HB-PEG scaffolds could enhance cartilage regeneration, showing their marvelous prospect as scaffolds for cartilage tissue engineering. [ABSTRACT FROM AUTHOR]

[Display omitted] Cartilage is severely limited in self-repair after damage, and tissue engineering scaffold transplantation is considered the most promising strategy for cartilage regeneration. However, scaffolds without cells and growth factors, which can effectively avoid long cell culture times, high risk of infection, and susceptibility to contamination, remain scarce. Hence, we developed a cell- and growth factor-dual free hierarchically structured nanofibrous sponge to mimic the extracellular matrix, in which the encapsulated core–shell nanofibers served both as mechanical supports and as long-lasting carriers for bioactive biomass molecules (glucosamine sulfate). Under the protection of the nanofibers in this designed sponge, glucosamine sulfate could be released continuously for at least 30 days, which significantly accelerated the repair of cartilage tissue in a rat cartilage defect model. Moreover, the nanofibrous sponge based on carboxymethyl chitosan as the framework could effectively fill irregular cartilage defects, adapt to the dynamic changes during cartilage movement, and maintain almost 100 % elasticity even after multiple compression cycles. This strategy, which combines fiber freeze-shaping technology with a controlled-release method for encapsulating bioactivity, allows for the assembly of porous bionic scaffolds with hierarchical nanofiber structure, providing a novel and safe approach to tissue repair. [ABSTRACT FROM AUTHOR]

Objective To prepare composite scaffolds for rat H9C2 cardiomyocytes, and to optimize the scaffolds that facilitate the growth of H9C2 cardiomyocytes. Methods The electrospinning method was used to prepare three types of compo-site scaffolds, i.e., polycaprolactone (PCL)/chitosan (CS) scaffold (scaffold A), PCL/CS/zinc oxide (ZnO) scaffold (scaffold B), and PCL/CS/ZnO/carbon nanotubes (CNTs) scaffold (scaffold C), and the preparation of scaffolds was verified by the methods including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric (TG) analysis, and Raman spectroscopy. Electron microscopy and tensile stress, water contact angle, conductivity, and expansion rate tests were used to eva-luate the physical and chemical properties of the three types of scaffolds, and DAPI staining, electron microscopy, and CCK-8 assay were used to evaluate the biocompatibility of the three types of scaffolds. Results XRD, FTIR spectroscopy, TG analysis, and Raman spectroscopy showed that the three types of scaffolds were successfully prepared. Electron microscopy showed that scaffold C had a significantly longer fiber diameter than scaffold A (F=73.050,t=8.724,9.747,P

Introduction: Physical factors like stiffness and surface features are among the characteristics that affect the performance of barrier membranes and determine the results of regenerative processes. A perfect equilibrium between the membrane’s rigidity and mechanical stability guarantees effective periodontal regeneration. The study’s novelty lies in comparing the physical characteristics, namely morphology, tensile strength, wettability, and biological characteristics, namely biocompatibility and enzyme resistance properties, of the Fix-GideTM membrane against the gold standard membrane, Bio-Gide®. Aim: To explore the physical and biological properties of two commercially available barrier membranes in oral tissue regeneration. Materials and Methods: The present in-vitro study compared two commercially available membranes, namely Bio-Gide® and Fix-GideTM. Both membranes are bilayered resorbable membranes, with Bio-Gide composed of porcine dermis Type-I and III collagen and Fix-GideTM of bovine origin. The study was conducted at the Central Leather Research Institute, and the membranes were procured from Sri Ramachandra Institute of Higher Education and Research. Morphological characterisation was done using Scanning Electron Microscopy (SEM). Physical properties were evaluated using a tensile strength test, enzyme resistance test, and wettability measurement. Biocompatibility assessment was also performed. The Statistical Package for Social Sciences (SPSS) software was used to run the Mann-Whitney U test to analyse the statistical data obtained in the enzyme resistance test. Results: Biocompatibility assessment showed no cytotoxic profile of both membranes, portraying their biocompatible nature. Morphological analysis using SEM showed the surface of the Bio-Gide® membrane to be considerably smoother than the Fix-GideTM membrane. Both membranes, however, have fibrous and porous features on their inner surfaces. Tensile strength assessment found that the percentage of elongation was better with Bio-Gide (1.7±0.4 and 4.8±0.4) when compared to Fix-Gide (15.8±0.2 and 2.2±0.2) in both wet and dry states, respectively. The enzyme resistance test evaluated in dry and wet settings showed that the membranes, namely, Bio-Gide® membrane exhibited around 29±2% of degradation, whereas the Fix-GideTM exhibited only 18±2%. These mechanical profiles exhibited that the membranes has appreciable differences, although there wasn’t a statistically significant difference between them (p=0.68). According to wettability studies, Bio-Gide is hydrophilic, but Fix-GideTM is hydrophobic. Conclusion: The observations of the present study showed that Fix-Gide had comparable physio-biological properties to that of the Bio-Gide membrane. This supports the suitability of the use of both membranes for various oral tissue regeneration procedures.

Hydrogels are widely used in biological dressing, tissue scaffolding, drug delivery, sensors, and other promising applications owing to their water‐rich soft structures, biocompatibility, and adjustable mechanical properties. However, most of the conventional hydrogels are isotropic. The anisotropic structures existed widely in the organizational structure of plants and animals, which played a crucial role in biological systems. In this work, a method of limited domain swelling to prepare anisotropic hydrogels is proposed. Through spatially controlled swelling, the extension direction of hydrogels can be limited by a tailored mold, further achieving anisotropic hydrogels with concentration gradients. The external solution serves as a swelling solution to promote swelling and extension of the hydrogel matrix in a mold which can control the extension direction. Due to the diversity of external solutions, the method can be applied to prepare a variety of stimulus‐responsive polymers. The limited domain swelling method is promising for the construction of anisotropic hydrogels with different structures and properties. [ABSTRACT FROM AUTHOR]

Tissue engineering scaffolds are three-dimensional structures that provide an appropriate environment for cellular attachment, proliferation, and differentiation. Depending on their specific purpose, these scaffolds must possess distinct features, including appropriate mechanical properties, porosity, desired degradation rate, and cell compatibility. This investigation aimed to fabricate a new nanocomposite scaffold using a 3D printing technique composed of poly(ε-caprolactone) (PCL)/Gelatin (GEL)/ordered mesoporous calcium-magnesium silicate (om-CMS) particles. Different weight ratios of om-CMS were added and optimized, and a series of scaffolds were constructed for comparison purposes, including PCL 50%/Gel 50%, PCL 50%/Gel 45%/om-CMS%5, and PCL 50%/Gel 40%/om-CMS%10. The optimized weight ratio of om-CMS was 10% without leaving behind negative effects on the filaments' structure. The scaffolds' physical and chemical properties were assessed using various techniques, and their degradation rate, bioactivity potential, cell viability, attachment, and ALP activity were evaluated in vitro. The results demonstrated that the PCL 50%/Gel 40%/om-CMS10% scaffold had promising potential for further studies in bone tissue regeneration. [ABSTRACT FROM AUTHOR]

An antioxidant, antibacterial, and biocompatible biomaterial is essential to repair skin wounds effectively. Here, we have employed two natural biopolymers, isabgol (ISAB) and konjac glucomannan (KGM), to prepare microporous scaffolds by freezing and lyophilization. The scaffolds are loaded with thymol (THY) to impart potent antioxidant and antibacterial activities. The physicochemical properties of the ISAB+KGM+THY scaffold, like porosity (41.8±2.4 %), swelling, and biodegradation, were optimal for tissue regeneration application. Compared to the control, ISAB+KGM+THY scaffolds promote attachment, migration, and proliferation of L929 fibroblasts. The antioxidant activity of the ISAB+KGM+THY scaffold was significantly improved after loading THY. This would protect the tissues from oxidative damage. The antibacterial activity of the ISAB+KGM+THY scaffold was significantly higher than that of the control, which would help prevent bacterial infection. The vascularization ability of the ISAB+KGM scaffold was not altered by incorporating THY in the ISAB+KGM scaffold. Therefore, a strong antioxidant, antibacterial, and biocompatible nature of the ISAB+KGM+THY scaffold could be useful for various biomedical applications. [ABSTRACT FROM AUTHOR]

Sulfur dots (S‐dots) eliminate the need of expensive and toxic conventional photocatalysts or transition metal in photoinduced reversible deactivation radical polymerization (photoRDRP). Herein, non‐metallic S‐dots mediated photoRDRP of N,N‐dimethyl acrylamide (DMA) are developed for the first time. This technique allows for the precise synthesis of narrow‐dispersed poly(N,N‐dimethyl acrylamide) (PDMA) and double hydrophilic poly(N, N‐dimethyl acrylamide)‐block‐poly(2‐hydroxyethyl acrylamide) (PDMA‐b‐PHEAA) diblock copolymer suitable for contaminant removal from water. Also, its subsequent modification into a poly(N,N‐dimethyl acrylamide)‐block‐poly(N‐(2‐((4‐vinylbenzyl)oxy)ethyl)acrylamide) (PDMA‐b‐PVBEAA) diblock copolymer gives ultra‐fast gelation and production of writable ink‐gel, which is exceptionally well‐suited for 3D printing applications, enabling the creation of precise and defined shapes. This innovative material serves as an intriguing scaffold for tissue engineering and other biomaterial applications, especially in areas that demand rapid and customizable manufacturing solutions. [ABSTRACT FROM AUTHOR]

Skinless, hierarchical porous 3D polymer scaffolds are of critical importance in tissue engineering, enabling improved cell infiltration, nutrient, metabolite and energy exchange, and biomimetic structures, crucial for regenerative medicine, drug delivery, and advanced material applications. However, it is still a great challenge to construct this kind of material with traditional 3D printing techniques. Herein, a novel simple, and versatile in situ precipitation‐assisted direct‐write‐3D printing strategy for skinless, hierarchical porous 3D scaffolds is reported. Homogenous ink containing molecularly dissolved fructose (soluble porogen molecule) and polymer (whether it is hydrophilic, hydrophobic or amphiphilic) is directly extruded into a nonsolvent bath, where simultaneously solidification of the polymer and in situ precipitation of the porogen molecules both on the exterior surface and inside the separated polymer fibers happen. Subsequently, by simply leaching the in situ formed porogen particles, skinless hierarchical porous polymeric 3D scaffolds can be obtained. It is believed that 3D printing, polymer/macromolecule‐based scaffolds, especially the skinless hierarchical porous biomaterials, and the tissue engineering market can benefit tremendously from this simple and versatile approach. [ABSTRACT FROM AUTHOR]

Introduction: Bacterial infection and biofilm formation contribute to impaired healing in chronic diabetic wounds. Staphylococcus aureus and Pseudomonas aeruginosa are found in human diabetic wound biofilms. They may develop antibiotic resistance, increasing the urgency for alternative or complementary therapies. Diabetic wound healing may be improved with the use of biomedically engineered scaffolds, which can also serve as delivery systems for antibacterial compounds. Manuka honey is a potent antibacterial and wound care agent due to its high osmolarity, low pH, and constituents (such as methylglyoxal). Honey exhibits bacteriostatic and bactericidal effects, modulates the expression of biofilm forming genes, and restores antibiotic susceptibility in previously drug resistant pathogens. Methods: In this study, we created a dermal regeneration template (DRT) composed of polycaprolactone-gelatin (PCL-gelatin) and Manuka honey to retain honey in the wound and also provide a scaffold for tissue regeneration. Results and discussion: Soluble Manuka honey inhibited the planktonic and biofilm growth of both S. aureus (UWH3) and P. aeruginosa (PA14) co-cultures. Manuka honey embedded PCL-gelatin scaffolds did not exhibit bacteriostatic or bactericidal effects on cocultures of UHW3 and PA14; however, they promoted the expression of AgrA, a gene associated with dispersal of S. aureus biofilms. [ABSTRACT FROM AUTHOR]

Composite track-etched membranes (CTeMs) emerged as a versatile and high-performance class of materials, combining the precise pore structures of traditional track-etched membranes (TeMs) with the enhanced functionalities of integrated nanomaterials. This review provides a comprehensive overview of the synthesis, functionalization, and applications of CTeMs. By incorporating functional phases such as metal nanoparticles and conductive nanostructures, CTeMs exhibit improved performance in various domains. In environmental remediation, CTeMs effectively capture and decompose pollutants, offering both separation and detoxification. In sensor technology, they have the potential to provide high sensitivity and selectivity, essential for accurate detection in medical and environmental applications. For energy storage, CTeMs may be promising in enhancing ion transport, flexibility, and mechanical stability, addressing key issues in battery and supercapacitor performance. Biomedical applications may benefit from the versality of CTeMs, potentially supporting advanced drug delivery systems and tissue engineering scaffolds. Despite their numerous advantages, challenges remain in the fabrication and scalability of CTeMs, requiring sophisticated techniques and meticulous optimization. Future research directions include the development of cost-effective production methods and the exploration of new materials to further enhance the capabilities of CTeMs. This review underscores the transformative potential of CTeMs across various applications and highlights the need for continued innovation to fully realize their benefits. [ABSTRACT FROM AUTHOR]

To repair damaged mesothelium tissue, which lines internal organs and cavities, a tissue engineering approach with mesothelial cells seeded to a functional nanostructured scaffold is a promising approach. Therefore, this study explored the uses of electrospun nanofiber membrane scaffolds (NMSs) as scaffolds for mesothelial cell culture and transplantation. We fabricated a composite NMS through electrospinning by blending polycaprolactone (PCL) with gelatin. The addition of gelatin enhanced the membrane's hydrophilicity while maintaining its mechanical strength and promoted cell attachment. The in vitro study demonstrated enhanced adhesion of mesothelial cells to the scaffold with improved morphology and increased phenotypic expression of key marker proteins calretinin and E-cadherin in PCL/gelatin compared to pure PCL NMSs. In vivo studies in rats revealed that only cell-seeded PCL/gelatin NMS constructs fostered mesothelial healing. Implantation of these constructs leads to the regeneration of new mesothelium tissue. The neo-mesothelium is similar to native mesothelium from hematoxylin and eosin (H&E) and immunohistochemical staining. Taken together, the PCL/gelatin NMSs can be a promising scaffold for mesothelial cell attachment, proliferation, and differentiation, and the cell/scaffold construct can be used in therapeutic applications to reconstruct a mesothelium layer. [ABSTRACT FROM AUTHOR]

Polylactic acid/chitosan (PLA/CS) and poly(vinyl alcohol)/chitosan (PVA/CS) are considered potential blends for use in tissue engineering, since when obtained in the form of 3D fibers they can form structures with high porosity, biocompatibility, antimicrobial activity and morphology similar to tissues and organs. However, there is a scarce number of reports in the literature addressing the production of systems based on 3D fibrous mixtures of PVA or PLA with high chitosan amount because of the difficulty in spinning CS into stable structures using acidic solutions, and without further employment of cross-linking agents. Therefore, this work focused on a novel procedure to prepare 3D fibrous structures of PVA and PLA with high chitosan content, combining the solution blow spinning technique, a heated air environment and the use of eco-friendly solvents, without using crosslinking agents. The influence of CS incorporation on the as-prepared structures was assessed by scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, contact angle measurement, porosity, swelling and degradation tests. Rheological tests evidenced that an increase in the CS content implies a greater viscosity of the spinning solutions, hindering the fibrillar structures formation. Fibers produced showed a randomly interconnected and highly porous fibrous cotton-wool-like structure, with fiber diameters ranging from 481 to 637 nm for PVA/CS systems, and from 1276 to 2050 nm for PLA/CS systems. A decrease in the thermal stability of the blend-based fibers and an increase in hydrophilicity, porosity, swelling and in vitro biodegradation were observed in the blend systems. Results indicate that the obtained fibrillar structures possess morphological and physical characteristics that may be interesting for application as 3D fibrous scaffolds in tissue engineering. [ABSTRACT FROM AUTHOR]

Bioactive ceramic bone scaffolds are limited by their brittleness. To address this limitation, we developed a new method for preparing β-tricalcium phosphate (β-TCP)/polycaprolactone (PCL) porous composite scaffolds with a gradient structure using digital light processing technology and an impregnation process. The composite scaffolds exhibited compressive strength comparable to that of pure β-TCP scaffolds but with substantially higher toughness and reliability, especially during in vitro degradation. Owing to the gradient structure, the composite scaffolds could gradually shift from high strength and stiffness to moderate strength and low stiffness, which is beneficial for bone healing and remodeling. In femoral condyle defects without mechanical stimulation, the β-TCP/PCL composite scaffolds exhibited slightly lower cellular compatibility and osteoinductive ability than those of the pure β-TCP scaffolds. However, in radial defects, composite scaffolds demonstrated a better mechanical response and bone growth capacity. The composite scaffolds maintained their structural integrity after 2–4 months, whereas the β-TCP scaffolds fractured within 2 months. This study provides a novel methodology for the development of effective scaffold fabrication strategies for load-bearing or large segmental defects with complex stress applications for use in bone healing and remodeling. [ABSTRACT FROM AUTHOR]

Recent interest in tissue engineering (TE) has focused on electrically conductive biomaterials. This has been inspired by the characteristics of the cells' microenvironment where signalling is supported by electrical stimulation. Numerous studies have demonstrated the positive influence of electrical stimulation on cell excitation to proliferate, differentiate, and deposit extracellular matrix. Even without external electrical stimulation, research shows that electrically active scaffolds can improve tissue regeneration capacity. Tissues like bone, muscle, and neural contain electrically excitable cells that respond to electrical cues provided by implanted biomaterials. To introduce an electrical pathway, TE scaffolds can incorporate conductive polymers, metallic nanoparticles, and ceramic nanostructures. However, these materials often do not meet implantation criteria, such as maintaining mechanical durability and degradation characteristics, making them unsuitable as scaffold matrices. Instead, depositing conductive layers on TE scaffolds has shown promise as an efficient alternative to creating electrically conductive structures. A stratified scaffold with an electroactive surface synergistically excites the cells through active top-pathway, with/without electrical stimulation, providing an ideal matrix for cell growth, proliferation, and tissue deposition. Additionally, these conductive coatings can be enriched with bioactive or pharmaceutical components to enhance the scaffold's biomedical performance. This review covers recent developments in electrically active biomedical coatings for TE. The physicochemical and biological properties of conductive coating materials, including polymers (polypyrrole, polyaniline and PEDOT:PSS), metallic nanoparticles (gold, silver) and inorganic (ceramic) particles (carbon nanotubes, graphene-based materials and Mxenes) are examined. Each section explores the conductive coatings' deposition techniques, deposition parameters, conductivity ranges, deposit morphology, cell responses, and toxicity levels in detail. Furthermore, the applications of these conductive layers, primarily in bone, muscle, and neural TE are considered, and findings from in vitro and in vivo investigations are presented. Tissue engineering (TE) scaffolds are crucial for human tissue replacement and acceleration of healing. Neural, muscle, bone, and skin tissues have electrically excitable cells, and their regeneration can be enhanced by electrically conductive scaffolds. However, standalone conductive materials often fall short for TE applications. An effective approach involves coating scaffolds with a conductive layer, finely tuning surface properties while leveraging the scaffold's innate biological and physical support. Further enhancement is achieved by modifying the conductive layer with pharmaceutical components. This review explores the under-reviewed topic of conductive coatings in tissue engineering, introducing conductive biomaterial coatings and analyzing their biological interactions. It provides insights into enhancing scaffold functionality for tissue regeneration, bridging a critical gap in current literature. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Different materials have been used as wound dressings after vital pulp therapies. Some of them have limitations such as delayed setting, difficult administration, slight degree of cytotoxicity, crown discoloration and high cost. Therefore, to overcome these disadvantages, composite scaffolds have been used in regenerative dentistry. This study aims to construct and characterize the physicochemical behavior of a novel injectable alginate hydrogel loaded with different bioactive glass nanoparticles in various concentrations as a regenerative pulpotomy filling material. Methods: Alginate hydrogels were prepared by dissolving alginate powder in alcoholic distilled water containing mesoporous bioactive glass nanoparticles (MBG NPs) or boron-doped MBG NPs (BMBG NPs) at 10 and 20 wt% concentrations. The mixture was stirred and incubated overnight in a water bath at 50 0 C to ensure complete solubility. A sterile dual-syringe system was used to mix the alginate solution with 20 wt% calcium chloride solution, forming the hydrogel upon extrusion. Then, constructed hydrogel specimens from all groups were characterized by FTIR, SEM, water uptake percentage (WA%), bioactivity and ion release, and cytotoxicity. Statistical analysis was done using One-Way ANOVA test for comparisons between groups, followed by multiple pairwise comparisons using Bonferroni adjusted significance level (p < 0.05). Results: Alginate/BMBG loaded groups exhibited remarkable increase in porosity and pore size diameter [IIB1 (168), IIB2 (183) (µm)]. Similarly, WA% increased (~ 800%) which was statistically significant (p < 0.05). Alginate/BMBG loaded groups exhibited the strongest bioactive capability displaying prominent clusters of hydroxyapatite precipitates on hydrogel surfaces. Ca/P ratio of precipitates in IIA2 and IIB1 (1.6) were like Ca/P ratio for stoichiometric pure hydroxyapatite (1.67). MTT assay data revealed that the cell viability % of human gingival fibroblast cells have declined with increasing the concentration of both powders and hydrogel extracts in all groups after 24 and 48 h but still higher than the accepted cell viability % of (˃70%). Conclusions: The outstanding laboratory performance of the injectable alginate/BMBGNPs (20 wt%) composite hydrogel suggested it as promising candidate for pulpotomy filling material potentially enhancing dentin regeneration in clinical applications. [ABSTRACT FROM AUTHOR]

Articular cartilage damage and wear can result in cartilage degeneration, ultimately culminating in osteoarthritis. Current surgical interventions offer limited capacity for cartilage tissue regeneration and offer only temporary alleviation of symptoms. Tissue engineering strategies are increasingly recognized as promising modalities for cartilage restoration. Currently, various biological scaffolds utilizing tissue engineering materials are extensively employed in both fundamental and clinical investigations of cartilage repair. In order to optimize the cartilage repair ability of tissue engineering scaffolds, researchers not only optimize the structure and properties of scaffolds from the perspective of materials science and manufacturing technology to enhance their histocompatibility, but also adopt strategies such as loading cells, cytokines, and drugs to promote cartilage formation. This review provides an overview of contemporary tissue engineering strategies employed in cartilage repair, as well as a synthesis of existing preclinical and clinical research. Furthermore, the obstacles faced in the translation of tissue engineering strategies to clinical practice are discussed, offering valuable guidance for researchers seeking to address these challenges. [ABSTRACT FROM AUTHOR]

AbstractOral diseases are a prevalent global issue, causing significant health and economic burdens that greatly diminish the quality of life for affected individuals. Tissue engineering strategies employing scaffolds offer a promising approach to restoring the original structures and biological functions of dental and dentoalveolar tissues. Among the various building materials, polysaccharides, known for their inherent biocompatibility, have gained significant attention. Topical advances in tissue engineering have led to the fabrication of composite scaffolds with the greatest utilization of favorable properties of each material. This review aims to explore the application of polysaccharide-based composite scaffolds for regenerating dental and dentoalveolar tissues, including both hard and soft tissues, as well as tissue complexes. To begin, we will provide a brief overview to commonly used polysaccharides. Subsequently, we will introduce the commonly used forms of composite polysaccharide scaffolds together with fabricating, engineering, and optimizing methods for dental and dentoalveolar tissue regeneration. Next, we will examine the latest progress and the potential of polysaccharide composite scaffolds in dental and dentoalveolar tissue regeneration applications. To conclude, this review will reflect on the limitations and prospects associated with polysaccharide composite scaffolds for dental and dentoalveolar tissue regeneration. By addressing these aspects, we aim to contribute to the understanding and development of effective strategies for improving oral health outcomes. [ABSTRACT FROM AUTHOR]

Electroactive scaffolds are increasingly used to mimic the microenvironment of electroactive tissues such as the heart and nerves. Multi-network hydrogels have emerged as an important platform in the field of tissue engineering. In this study, alginate (Alg)-based conductive and multi-network nanocomposite hydrogels were prepared and characterized as promising scaffolds for electroactive tissues. Alg, which is derived from natural sources, was modified with methacrylate (AlgMA) to render it photosensitive (photoactive). Multiwall carbon nanotubes (MWCNTs) were chosen as potential nanomaterials for electrical conductivity. MWCNTs were modified with –COOH groups to produce MWCNT–COOH nanomaterials. Nanocomposite hydrogels were fabricated by incorporating 0.5%, 1.0%, and 3.0 wt% of MWCNT–COOH into the AlgMA network. The hydrogel scaffolds were assessed for their chemical, physical, mechanical, electrical, and biological characteristics. This study demonstrated that incorporating modified MWCNTs into an AlgMA network enhances its electrical activity. According to our results, good rheological properties, natural tissue-like mechanical properties, optimal electrical conductivity, and biological performance make AlgMA/MWCNT–COOH multi-network nanocomposite hydrogels crucial in the field of electroactive tissues. [ABSTRACT FROM AUTHOR]

Degenerative disc disease is the leading cause of lower back and leg pain, considerably impacting daily life and incurring substantial medical expenses for those affected. The development of annulus fibrosus tissue engineering offers hope for treating this condition. However, the current annulus fibrosus tissue engineering scaffolds fail to accurately mimic the natural biological environment of the annulus fibrosus, resulting in limited secretion of extracellular matrix produced by the seeded cells and poor biomechanical properties of the constructed biomimetic annulus fibrosus tissue. This inability to match the biomechanical performance of the natural annulus fibrosus hinders the successful treatment of annulus fibrosus defects. In this study, we fabricated decellularized annulus fibrosus matrix (DAFM)/chitosan hydrogel-1 (DAFM: Chitosan 6:2) and DAFM/chitosan hydrogel-2 (DAFM: Chitosan 4:4) by varying the ratio of DAFM to chitosan. Rat annulus fibrosus (AF)-derived stem cells were cultured on these hydrogel scaffolds, and the cell morphology, AF-related gene expression, and Interleukin-6 (IL-6) levels were investigated. Additionally, magnetic resonance imaging, Hematoxylin and eosin staining, and Safranine and Fast Green staining were performed to evaluate the repair effect of the DAFM/chitosan hydrogels in vivo. The gene expression results showed that the expression of Collagen type I (Col-I), Collagen type I (Col-II), and aggrecan by annulus fibrosus stem cells (AFSCs) cultured on the DAFM/chitosan-1 hydrogel was higher compared with the DAFM/chitosan-2 hydrogel. Conversely, the expression of metalloproteinase-9 (MMP-9) and IL-6 was lower on the DAFM/chitosan-1 hydrogel compared with the DAFM/chitosan-2 hydrogel. In vivo, both the DAFM/chitosan-1 and DAFM/chitosan-2 hydrogels could partially repair large defects of the annulus fibrosus in rat tail vertebrae. In conclusion, the DAFM/chitosan-1 hydrogel could be regarded as a candidate scaffold material for the repair of annulus fibrosus defects, offering the potential for improved treatment outcomes. [ABSTRACT FROM AUTHOR]

One of the challenges and limitations of bone tissue engineering includes fast degradation rates, reduced bioactivity, donor site morbidity, and unresolved risks of pathogen transmission. In the field of bone tissue engineering, gradient materials are promising for treating bone defects because they can create graded structures and compositions similar to natural bone. By controlling the amount of components in the structure, the degradation rate, bioactivity, and osteogenic capacity can be manipulated. In the current study, a gradient, multilayer, porous nanocomposite of calcium sulfate/glass (Gn CS/BG) with a gelatin coating (Gn CS/BG-Gel) was prepared using rotational casting technique. The SEM results showed an average pore size of approximately 400 μm within the Gn CS/BG-Gel nanocomposite. An elastic modulus (E) of around 240 MPa and an ultimate tensile strength (σ) of approximately 5.5 MPa were achieved for Gn CS/BG-Gel nanocomposite. The degradation analysis in a dynamic tris-buffer environment revealed a degradation rate of 68 % over a 63-day period, with a decrease in degradation rate as the bioactive glass (BG) content increased in each layer, indicating the influence of BG on the degradation process. The bioactivity results in a dynamic simulated body fluid suggested that increased BG content in each layer promoted hydroxyapatite formation, indicating improved bioactive behavior. The evaluation of ion release with ICP-OES, MTT and Acridine Orange assays using human bone marrow-derived mesenchymal stem cells (hBMSCs) confirmed the non-toxic nature of Gn CS/BG-Gel. Assessments of alkaline phosphatase (ALP) activity, calcium content, Alizarin Red staining and cell attachment behavior substantiated the osteogenic potential of Gn CS/BG-Gel. Collectively, the three-dimensional structure along with the Gn CS/BG-Gel composition contributed to the enhanced cellular responses. These findings hold significant promise for the development of biomaterials with potential applications in bone tissue engineering, and they contribute valuable insights to the field. [Display omitted] [ABSTRACT FROM AUTHOR]

Recently, advancements in fabrication technology have brought a new aspect to the field of tissue engineering. By utilizing advanced techniques in 3D manufacturing and biomaterials, scientists have successfully created tissue engineering scaffolds with complex three-dimensional structures and customized chemical compositions that closely mimic the natural environment of living tissues. These methodologies show potential not only for developing therapies that restore lost tissue function but also for creating in vitro models that replicate living tissue. The current investigation involved the synthesis of methacrylated polycaprolactone (PCLMA) by incorporating methacryloyl chloride (Meth-Cl) into polycaprolactone (PCL) with a molecular weight of 80,000 Da. Afterwards, PCLMA was subjected to crosslinking with glycerol acrylate (GA) and, by utilizing Diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO) as a photoinitiator, achieved the three-dimensional (3D) printing of tissue materials using Stereolithography (SLA). Analytical techniques included nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Cell viability was investigated using Human Osteoblast (HOB) cells. The biocompatibility of glycerol acrylate (GA) crosslinked polymethacrylated polycaprolactone (PCLMA) was confirmed using cell viability experiments. Overall, the GA-crosslinked PCLMA bioresin, particularly PCLMA-8, shows promise for further use in tissue engineering applications. [ABSTRACT FROM AUTHOR]

The skin is crucial for homeostasis and body defense, requiring quick healing to maintain internal balance. Initially used for bone repair, calcium hydroxyapatite (HAp) is now being studied for soft tissue engineering. This literature review investigated HAp's role in tissue repair through searches on PubMed, Scopus (Elsevier), Science Direct, Springer Link, and Google Scholar databases without time restrictions, using keywords "hydroxyapatite AND skin AND wound" and "hydroxyapatite AND skin repair". Inclusion criteria encompassed in vivo studies in humans and animals, English publications, full access, and sufficient data on HAp's role in tissue repair. Exclusions included duplicates, unrelated articles, editor letters, reviews, comments, conference abstracts, dissertations, and theses. Out of the 472 articles initially identified, 139 met the inclusion criteria, with 21 focusing on HAp for tissue repair. Findings indicate that HAp and nano-HAp in skin regeneration are promising, especially when combined with other biomaterials, offering antimicrobial and anti-inflammatory benefits and stimulating angiogenesis. This suggests their potential application in dermatology, surgery, and dentistry, extending HAp's versatility from hard tissues to enhancing critical properties for soft tissue repair and accelerating healing. [ABSTRACT FROM AUTHOR]

Rotator cuff repair is a common orthopaedic procedure. Despite advancements in the mechanics of rotator cuff repair, the re-tear rate post repair remains significant. This review assesses the available literature on usage of collagen bio-inductive scaffolds for rotator cuff repairs. Augmentation of biology is a key strategy to improving success of rotator cuff repair. Current evidence suggests that augmentation of rotator cuff repairs with a collagen bio-inductive scaffold improves the thickness of the rotator cuff. There is a favourable safety profile, and its usage may improve re-tear rates. However, there is currently no consensus on whether clinical outcomes are improved by the usage of collagen bio-inductive scaffolds. Further research is necessary to increase our understanding of the clinical effects of using collagen bio-inductive scaffolds and to determine which patient profiles will best benefit from its usage. [ABSTRACT FROM AUTHOR]

This review research aims to enhance the sustainability and functionality of shape-memory polymer composites (SMPCs) by integrating advanced 4D printing technologies and sustainable manufacturing practices. The primary objectives are to reduce environmental impact, improve material efficiency, and expand the design capabilities of SMPCs. The methodology involved incorporating recycled materials, bio-based additives, and smart materials into 4D printing processes, and conducting a comprehensive environmental impact and performance metrics analysis. Significant findings include a 30% reduction in material waste, a 25% decrease in energy consumption during production, and a 20% improvement in shape-memory recovery with a margin of error of ±3%. Notably, the study highlights the potential use of these SMPCs as biomimetic structural biomaterials and scaffolds, particularly in tissue engineering and regenerative medicine. The ability of SMPCs to undergo shape transformations in response to external stimuli makes them ideal for creating dynamic scaffolds that mimic the mechanical properties of natural tissues. This increased design flexibility, enabled by 4D printing, opens new avenues for developing complex, adaptive structures that support cell growth and tissue regeneration. In conclusion, the research demonstrates the potential of combining sustainable practices with 4D printing to achieve significant environmental, performance, and biomedical advancements in SMPC manufacturing. [ABSTRACT FROM AUTHOR]

Calcium-based materials, such as calcium carbonate, calcium phosphate, and calcium silicate, have attracted significant attention in biomedical research, owing to their unique physicochemical properties and versatile applications. The distinctive characteristics of these materials, including their inherent biocompatibility and tunable structures, hold significant promise for applications in bone regeneration and tissue engineering. This review explores the biomedical applications of calcium-containing materials, particularly for bone regeneration. Their remarkable biocompatibility, tunable nanostructures, and multifaceted functionalities make them pivotal for advancing regenerative medicine, drug delivery system, and biomimetic scaffold applications. The evolving landscape of biomedical research continues to uncover new possibilities, positioning calcium-based materials as key contributors to the next generation of innovative biomaterial scaffolds. [ABSTRACT FROM AUTHOR]

Osteochondral lesions may be due to trauma or congenital conditions. In both cases, therapy is limited because of the difficulty of tissue repair. Tissue engineering is a promising approach that relies on designed scaffolds with variable mechanical attributes to favor cell attachment and differentiation. Human adipose-derived stem cells (hASCs) are a very promising cell source in regenerative medicine with osteochondrogenic potential. Based on the assumption that stiffness influences cell commitment, we investigated three different scaffolds: a semisynthetic animal-derived GelMA hydrogel, a combined scaffold made of rigid PEGDA coated with a thin GelMA layer and a decellularized plant-based scaffold. We investigated the role of different biomechanical stimulations in the scaffold-induced osteochondral differentiation of hASCs. We demonstrated that all scaffolds support cell viability and spontaneous osteochondral differentiation without any exogenous factors. In particular, we observed mainly osteogenic commitment in higher stiffness microenvironments, as in the plant-based one, whereas in a dense and softer matrix, such as in GelMA hydrogel or GelMA-coated-PEGDA scaffold, chondrogenesis prevailed. We can induce a specific cell commitment by combining hASCs and scaffolds with particular mechanical attributes. However, in vivo studies are needed to fully elucidate the regenerative process and to eventually suggest it as a potential approach for regenerative medicine. [ABSTRACT FROM AUTHOR]

Three-dimensional cancer cell cultures have been a valuable research model for developing new drug targets in the preclinical stage. However, there are still limitations to these in vitro models. Scaffold-based systems offer a promising approach to overcoming these challenges in cancer research. In this study, we show that two-photon polymerization (TPP)-assisted printing of scaffolds enhances 3D tumor cell culture formation without additional modifications. TPP is a perfect fit for this task, as it is an advanced 3D-printing technique combining a μm-level resolution with complete freedom in the design of the final structure. Additionally, it can use a wide array of materials, including biocompatible ones. We exploit these capabilities to fabricate scaffolds from two different biocompatible materials—PEGDA and OrmoClear. Cubic spheroid scaffolds with a more complex architecture were produced and tested. The biological evaluation showed that the human ovarian cancer cell lines SKOV3 and A2780 formed 3D cultures on printed scaffolds without a preference for the material. The gene expression evaluation showed that the A2780 cell line exhibited substantial changes in CDH1, CDH2, TWIST, COL1A1, and SMAD3 gene expression, while the SKOV3 cell line had slight changes in said gene expression. Our findings show how the scaffold architecture design impacts tumor cell culture 3D spheroid formation, especially for the A2780 cancer cell line. [ABSTRACT FROM AUTHOR]

Porous Ti-6Al-4V scaffold materials can be used to heal massive bone defects because they can provide space for vascularisation and bone formation. During new bone tissue development, rapid vascular ingrowth into scaffold materials is very important. Osteoblast-derived exosomes are capable of facilitating angiogenesis–osteogenesis coupling. Low-intensity pulsed ultrasound (LIPUS) is a physical therapy modality widely utilised in the field of bone regeneration and has been proven to enhance the production and functionality of exosomes on two-dimensional surfaces. The impact of LIPUS on exosomes derived from osteoblasts cultured in three dimensions remains to be elucidated. In this study, exosomes produced by osteoblasts on porous Ti-6Al-4V scaffold materials under LIPUS and non-ultrasound stimulated conditions were co-cultured with endothelial cells. The findings indicated that the exosomes were consistently and stably taken up by the endothelial cells. Compared to the non-ultrasound group, the LIPUS group facilitated endothelial cell proliferation and angiogenesis. After 24 h of co-culture, the migration ability of endothelial cells in the LIPUS group was 17.30% higher relative to the non-ultrasound group. LIPUS may represent a potentially viable strategy to promote the efficacy of osteoblast-derived exosomes to enhance the angiogenesis of porous Ti-6Al-4V scaffold materials. [ABSTRACT FROM AUTHOR]

Background: Connective tissue graft substitutes have been used widely to overcome autogenous graft limitations. Nevertheless, they do not provide comparable results in the treatment of periodontal and peri‐implant soft tissue defects. Based on the principles of tissue‐engineered materials, injectable platelet‐rich fibrin (i‐PRF) has been combined with collagen matrices (CMs) to enhance their clinical efficacy. To the best of our knowledge, this is the first case series demonstrating the use of i‐PRF for the biofunctionalization of a volume‐stable collagen matrix (VCMX) as an adjunct to coronally advanced flap (CAF) to treat single gingival recession (GR) defects. Methods & Results: The study included 10 patients. Bleeding on probing, probing depth, GR height, clinical attachment level, esthetics, and dentin hypersensitivity were evaluated. After 6 months, a significant GR reduction (RecRed: 2.15 ± 0.7 mm; p = 0.005) and percentage of root coverage (% RC) of 81.13% were observed. Additionally, 40% of the sites showed complete root coverage. Gingival thickness increased 0.64 mm. Patient‐centered evaluations demonstrated dentin hypersensitivity and esthetics improvements by the end of follow‐up. Conclusion: VCMX biofunctionalized with i‐PRF associated with CAF technique showed promising clinical outcomes in the treatment of single RT1 GR defects. [ABSTRACT FROM AUTHOR]

The rapid evolution of clinical medicine, materials science, and regenerative medicine has rendered traditional implantable scaffolds inadequate for addressing the complex therapeutic demands of various diseases. Currently, implantable scaffolds in clinical practice are mainly made of metal, with the disadvantages of high stiffness, poor toughness, and low deformation. This paper offers a thorough review of shape memory scaffolds (SMSs), emphasizing their distinctive self‐recovery and adaptive functionalities that enhance compatibility with injured tissues, surpassing the capabilities of conventional metallic biomaterials. It delves into the limitations of current clinical scaffolds and the requisite performance metrics for effective implants and outlines the essential materials and fabrication methods for SMSs. Moreover, we enumerate the biomedical applications of SMMs with different response types, including thermology‐responsive, water‐responsive, and light‐responsive. The discussion extends to the burgeoning applications of SMSs in biomedical engineering, including their utility in bone tissue engineering, cardiovascular stenting, tubular structures, and cardiac patches, which underscore their potential in minimally invasive procedures and dynamic tissue interactions. This review concludes with an analysis of current challenges and prospects, providing valuable insights for developing and applying SMSs in the biomedical sector. [ABSTRACT FROM AUTHOR]

Since the introduction of 3D printing to biomedical fields, numerous advancements have been achieved in tissue engineering due to the advantages it offers. However, 3D-printed polymeric scaffolds may lack certain properties, impacting their functionality and success, such as bioactivity and cell affinity. In this study, the dip coating method was employed to enhance the biological and mechanical properties of 3D-printed polylactic acid (PLA) scaffolds using fused deposition modeling (FDM) technology. Specifically, the scaffolds were dip-coated with a polyvinyl alcohol (PVA)/nano-diopside solution. The thermal features of the 3D-printed scaffolds were analyzed using the differential scanning calorimetry method, revealing a calculated crystallinity of about 13%. To assess bioactivity, both coated and non-coated scaffolds were immersed in simulated body fluid (SBF) for 28 days, and their evaluation was conducted through scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDAX). At 40 °C, compared to the thermal conductivity of the nanofluid, the thermal conductivities of the non-coated 3D-printed sample and the coated 3D-printed sample were reduced by 9.91 and 22.52%, respectively. The results of this study guided the design and fabrication of improved tissue engineering scaffolds for bone regeneration applications. [ABSTRACT FROM AUTHOR]

The electrospinning process is an effective technique for creating micro- and nanofibers from synthetic and natural polymers, with significant potential for biomedical applications and drug delivery systems due to their high drug-loading capacity, large surface area, and tunable release times. Poly(L-lactic acid) (PLLA) stands out for its excellent thermo-mechanical properties, biodegradability, and bioabsorbability. Electrospun PLLA nanofibrous structures have been extensively investigated as wound dressings, sutures, drug delivery carriers, and tissue engineering scaffolds. This study aims to create and characterize electrospun PLLA membranes loaded with spironolactone (SP), mimicking active compounds of Ganoderma lucidum (GL), to develop a biodegradable patch for topical wound-healing applications. GL, a medicinal mushroom, enhances dermal wound healing with its bioactive compounds, such as polysaccharides and ganoderic acids. Focusing on GL extracts—obtained through green extraction methods—and innovative drug delivery, we created new fibers for wound-healing potential applications. To integrate complex mixtures of bioactive compounds into the fibers, we developed a prototype using a single pure substance representing the extract mixture. This painstaking work presents the results of the fabricating, wetting, moisture properties, material resilience, and full characterization of the product, providing a robust rationale for the fabrication of fibers imbued with more complex extracts. [ABSTRACT FROM AUTHOR]

Bone has the ability to heal itself; however, bone defects fail to heal once the damage exceeds a critical size. Bone regeneration remains a significant clinical challenge, with autograft considered the ideal bone graft material due to its sufficient porosity, osteogenic cells, and biological growth factors. However, limitations to bone grafting, such as limited bone stock and high resorption rates, have led to a great deal of research into developing bone graft substitutes. The P28 peptide is a small molecule bioactive biomimetic alternative to mimic the bone morphogenetic protein 2 (BMP-2). In this study, we investigated the potential of P28-loaded hybrid scaffolds to mimic the natural bone structure for enhancing the bone regeneration process. We hypothesized that the peptide-loaded scaffolds and nude scaffolds both have the potential to promote bone healing, and the bone healing process is accelerated by the release of the peptide. To verify our hypothesis, C2C12 cells were evaluated for the presence of calcium deposits by histological stain at 7 and 14 days in cultures with hybrid scaffolds. Total RNA was isolated from C2C12 cells cultured with hybrid scaffolds for 7 and 14 days to assess osteoblast differentiation. The project findings demonstrated that the hybrid scaffold could enhance osteoblast differentiation and significantly improve the therapeutic effects of the scaffold in bone regeneration. [ABSTRACT FROM AUTHOR]

Objectives: The high porosity of tissue engineering scaffolds is advantageous as they provide a high degree of infiltration of nutrients, enable cell penetration, and support vascularisation. However, the mechanical strength is also critical for providing structural support to the defect site throughout the regeneration process. In this study, we aimed to establish a relationship between internal phase volume and emulsion-templated scaffolds' physical, morphological and mechanical characteristics. Methods: In this work, tetra methacrylate functionalised polycaprolactone (4PCLMA) polymers were synthesised via ring-opening polymerisation followed by methacrylation. 4PCLMA-based emulsion templated matrices with 60%, 75% and 82% internal phase volumes were fabricated (P60, P75, and P82). These scaffolds' densities, porosities, average pore and window sizes, degree of interconnectivity values, and mechanical properties were investigated. Results: Increasing internal phase volume reduced the density of the foams by almost two-fold. No direct correlation was observed between average pore size and internal phase volume. Both the average window sizes and the degree of interconnectivity values increase with increasing internal phase volume. Compression modulus values are calculated as 0.46±0.04 MPa, 0.23±0.02 MPa and 0.14±0.01 MPa for P60, P75, and P82, respectively. Increasing internal phase volume from 60% to 82% caused a more than 2-fold reduction in the stiffness of the emulsion-templated matrices. Conclusions: Accordingly, by reporting on this experimental framework, we established a relationship between internal phase volume and the physical, morphological and mechanical characteristics of 4PCMA-based scaffolds to precisely engineer these characteristics for specific tissue engineering applications. [ABSTRACT FROM AUTHOR]

Fe-Ca-SAPO-34/CS/PANI, a novel hybrid bio-composite scaffold with potential application in dental tissue engineering, was prepared by freeze drying technique. The scaffold was characterized using FT-IR and SEM methods. The effects of PANI on the physicochemical properties of the Fe-Ca-SAPO-34/CS scaffold were investigated, including changes in swelling ratio, mechanical behavior, density, porosity, biodegradation, and biomineralization. Compared to the Fe-Ca-SAPO-34/CS scaffold, adding PANI decreased the pore size, porosity, swelling ratio, and biodegradation, while increasing the mechanical strength and biomineralization. Cell viability, cytotoxicity, and adhesion of human dental pulp stem cells (hDPSCs) on the scaffolds were investigated by MTT assay and SEM. The Fe-Ca-SAPO-34/CS/PANI scaffold promoted hDPSC proliferation and osteogenic differentiation compared to the Fe-Ca-SAPO-34/CS scaffold. Alizarin red staining, alkaline phosphatase activity, and qRT-PCR results revealed that Fe-Ca-SAPO-34/CS/PANI triggered osteoblast/odontoblast differentiation in hDPSCs through the up-regulation of osteogenic marker genes BGLAP, RUNX2, and SPARC. The significance of this study lies in developing a novel scaffold that synergistically combines the beneficial properties of Fe-Ca-SAPO-34, chitosan, and PANI to create an optimized microenvironment for dental tissue regeneration. These findings highlight the potential of the Fe-Ca-SAPO-34/CS/PANI scaffold as a promising biomaterial for dental tissue engineering applications, paving the way for future research and clinical translation in regenerative dentistry. [ABSTRACT FROM AUTHOR]

Tendinopathy is a leading cause of mobility issues. Currently, the cell–matrix interactions involved in the development of tendinopathy are not fully understood. In vitro tendon models provide a unique tool for addressing this knowledge gap as they permit fine control over biochemical, micromechanical, and structural aspects of the local environment to explore cell–matrix interactions. In this study, direct-write, near-field electrospinning of gelatin solution was implemented to fabricate micron-scale fibrous scaffolds that mimic native collagen fiber size and orientation. The stiffness of these fibrous scaffolds was found to be controllable between 1 MPa and 8 MPa using different crosslinking methods (EDC, DHT, DHT+EDC) or through altering the duration of crosslinking with EDC (1 h to 24 h). EDC crosslinking provided the greatest fiber stability, surviving up to 3 weeks in vitro. Differences in stiffness resulted in phenotypic changes for equine tenocytes with low stiffness fibers (∼1 MPa) promoting an elongated nuclear aspect ratio while those on high stiffness fibers (∼8 MPa) were rounded. High stiffness fibers resulted in the upregulation of matrix metalloproteinase (MMPs) and proteoglycans (possible indicators for tendinopathy) relative to low stiffness fibers. These results demonstrate the feasibility of direct-written gelatin scaffolds as tendon in vitro models and provide evidence that matrix mechanical properties may be crucial factors in cell–matrix interactions during tendinopathy formation. [ABSTRACT FROM AUTHOR]

Here, a novel kind of composite scaffold was fabricated by loading vascular endothelial growth factor (VEGF) and gastrodin liposome (GAS-LP) into electrospun silk fibroin/graphene oxide(SF/GO)nanofibrous and silk fibroin sponge-filled, respectively. Our results demonstrated that VEGF and GAS exhibited different release patterns in vitro which VEGF showed rapid release rate in the first few days while GAS was released slowly and continuously as encapsulated in liposomes. The scaffolds realized the combination of intraneural vascularization drugs and electrical stimulation effectively, leading to enhanced growth of RSC96 cells. Furthermore, the scaffolds could protect RSC96 cells in an inflammatory environment. [ABSTRACT FROM AUTHOR]

Nerve repair and regeneration are still challenging issues in the world, mainly due to the complex anatomic structure and limited regeneration ability of natural nerves. Tissue engineering provides a structure and function similar to nerve tissue through scaffold materials, seed cells, and active factors, which is a promising method to treat nerve injury. Gelatin methacrylate (GelMA) hydrogel is a kind of gelatin modified by methacrylamide, which possesses adjustable mechanical properties, convenient processability, and excellent biocompatibility, has been widely used in nerve tissue engineering. In this paper, the research progress of GelMA-based hydrogel in nerve repair and regeneration in recent five years is reviewed, with emphasis on the advanced manufacturing technologies of three-dimensional (3D) GelMA scaffold and the application systems that can effectively promote nerve repair and regeneration. We also evaluated the challenges and prospects of GelMA-based hydrogels in the field of nerve repair and regeneration, which is of guiding significance to the research of nerve tissue engineering. [ABSTRACT FROM AUTHOR]

Revitalization has emerged as an innovative treatment approach for immature permanent teeth with necrotic pulp. This article presents a comprehensive analysis of revitalization, focusing on its principles, clinical protocols and outcomes. The article highlights the importance of thorough diagnosis and assessment of the pulp and peri-apical condition to determine the suitability of revitalization. Various factors influencing the success of revitalization, such as the use of scaffolds, growth factors and stem cells, are discussed. Additionally, a case that was treated with a PRP scaffold is also presented. Overall, revitalization shows promise in promoting pulp regeneration and improving treatment outcomes in selected cases of pulp necrosis. CPD/Clinical Relevance: To introduce research-based knowledge to GDPs about the procedure and prognosis of tooth revitalization. [ABSTRACT FROM AUTHOR]