Search Results (216)

Bone grafting is essential for the regeneration of bone defects where natural healing is inadequate. Octacalcium phosphate (OCP)/calcium citrate (CC)/pig gelatin (pig Gel) composites promote hydroxyapatite (HAp) formation in simulated body fluid (SBF); however, the rapid degradation of pig Gel leads to their degradation in SBF within 7 d. To address this, we developed a 35% OCP/35% CC/30% methacrylated gelatin (GelMA) composite by leveraging the tuneable photo-crosslinking ability of GelMA to enhance the initial structural stability in SBF. However, the optimal synthetic photo-crosslinking conditions and the apatite-forming abilities of the OCP/CC/GelMA composite require investigation. In this study, we employed photo-crosslinking to synthesize homogeneous OCP/CC/GelMA composites with initial structural stability in SBF and evaluated their HAp-forming ability in SBF as an indicator of osteogenic potential, in comparison with the OCP/CC/pig Gel composites. Both GelMA- and pig Gel-based composites were prepared and immersed in SBF for 7 d to assess HAp formation. Although the OCP/CC/GelMA composite showed reduced HAp nucleation compared to the OCP/CC/pig Gel composites, it exhibited enhanced initial structural stability in SBF while retaining its HAp-forming ability. These findings highlight the OCP/CC/GelMA composite as a stable and promising scaffold for bone regeneration, laying the groundwork for further research. Full article

Tissue engineering is a growing field with multidisciplinary players in cell biology, engineering, and medicine, aiming to maintain, restore, or enhance functions of tissues and organs. The extracellular matrix (ECM) plays fundamental roles in tissue development, maintenance, and repair, providing not only structural support, but also critical biochemical and biomechanical cues that regulate cell behavior and signaling. Although its specific composition varies across different tissue types and developmental stages, matrix molecules influence various cell functional properties in every tissue. Given the importance of ECM in morphogenesis, tissue homeostasis, and regeneration, ECM-based bioscaffolds, developed through tissue engineering approaches, have emerged as pivotal tools for recreating the native cellular microenvironment. The aim of this study is to present the main categories of these scaffolds (i.e., natural, synthetic, and hybrid), major fabrication techniques (i.e., tissue decellularization and multidimensional bioprinting), while highlighting the advantages and disadvantages of each category, focusing on biological activity and mechanical performance. Scaffold properties, such as mechanical strength, elasticity, biocompatibility, and biodegradability are essential to their function and integration into host tissues. Applications of ECM-based bioscaffolds span a range of engineering and regenerative strategies, including cartilage, bone, cardiac tissue engineering, and skin wound healing. Despite promising advances, challenges remain in standardization, scalability, and immune response modulation, with future directions directed towards improving ECM-mimetic platforms. Full article

Human adipose stem cells (ASCs) are multipotent cells expressing mesenchymal stem cell (MSC) markers that are capable of multilineage differentiation and secretion of bioactive factors. Their “homing” to injured tissues is mediated by chemokines, cytokines, adhesion molecules, and signaling pathways. Enhancing ASC homing is critical for improving regenerative therapies. Strategies include boosting chemotactic signaling, modulating immune responses to create a supportive environment, preconditioning ASCs with hypoxia or mechanical stimuli, co-culturing with supportive cells, applying surface modifications or genetic engineering, and using biomaterials to promote ASC recruitment, retention, and integration at injury sites. Scaffolds provide structural support and a biomimetic environment for ASC-based tissue regeneration. Natural scaffolds promote adhesion and differentiation but have mechanical limitations, while synthetic scaffolds offer tunable properties and controlled degradation. Functionalization with bioactive molecules improves the regenerative outcomes of different tissue types. Ceramic-based scaffolds, due to their strength and bioactivity, are ideal for bone healing. Composite scaffolds, combining polymers, ceramics, or metals, further optimize mechanical and biological properties, supporting personalized regenerative therapies. This review integrates concepts from cell biology, biomaterials science, and regenerative medicine to offer a comprehensive understanding of ASC homing and its impact on tissue engineering and clinical applications. Full article

Background and Objectives: Demineralized bone matrix (DBM) is a widely used bone graft substitute due to its osteoconductive and osteoinductive properties. However, its efficacy varies due to differences in donor, processing, and storage conditions. Synthetic alternatives, such as iFactor^®, combine non-organic bone mineral and a small peptide (P-15) to enhance the cellular attachment and osteogenesis. To compare the osteogenic potential and bone matrix maturity of iFactor^® and a commercial DBM scaffold through calcium nodule formation and Fourier transform infrared spectroscopy (FTIR) analysis. Materials and Methods: Human mesenchymal stem cells (hMSCs) were cultured and exposed to iFactor^® or DBM in paracrine culture conditions for 21 days. Calcium nodule formation was assessed using alizarin red staining and quantified spectrophotometrically. The FTIR analysis of hMSCs exposed to the scaffolds for three months evaluated the biomolecular composition and bone matrix maturity. Results: Calcium nodules formed in both groups but in smaller quantities than in the positive control (p < 0.05). The biomolecular components of the DBM were similar to healthy bone (p > 0.05) than those of the iFactor^® group (p < 0.005). A different rate of bone regeneration was observed through the formation of a greater number of calcium nodule aggregates identified in the extracellular matrix of mesenchymal stem cell cultures exposed to iFactor^® compared to those cultures enriched with DBM. Conclusions: Both experimental matrices demonstrated similar osteogenic potential at the 3-month follow-up. Although DBM has a closer biomolecular composition and carbonate substitution compared to healthy bone, iFactor^® showed faster matrix maturity expressed through the formation of a greater number of calcium nodule aggregates and higher hMSCs proliferation. Full article

Natural biomaterials have gained significant attention in modern dentistry due to their biocompatibility, biodegradability, and low immunogenicity. These materials, including alginate, cellulose, chitosan, collagen, and hydroxyapatite, have been widely explored for their applications in stomatology. They play a crucial role in periodontal disease treatment, caries prevention, and implantology, providing an alternative to synthetic materials. Natural polymers such as chitosan and cellulose are utilized in drug delivery systems and tissue regeneration, while hydroxyapatite serves as a bone substitute due to its osteoconductive properties. Collagen-based scaffolds and coatings enhance periodontal and bone tissue regeneration. Additionally, bioengineered and chemically modified biomaterials offer improved mechanical and biological characteristics, expanding their clinical applications. This review aims to provide a comprehensive analysis of the biological properties, advantages, and limitations of selected natural biomaterials in dentistry. It explores their applications in various aspects of stomatology, including periodontal disease prevention and regeneration, dental caries prevention, bone substitutes in implantology, and dental implant coating. Although natural biomaterials exhibit promising properties, further research is necessary to refine their performance, enhance stability, and ensure long-term safety. Advancements in nanotechnology and bioengineering continue to drive the development of innovative natural biomaterials, paving the way for more effective and biocompatible dental therapies. Full article

(1) Background: Alveolar bone regeneration in dentistry has become important with the evolution of implantology. Biomaterials used for bone grafting are increasingly used to provide resistant bone support that is favorable for the insertion of dental implants. The aim of the study was to analyze the degree of biocompatibility and bone neoformation of two biomaterials compared to natural healing. (2) Methods: Bone defects of 3 mm diameter were created in the calvaria of 15 adult male Wistar rats. Three groups were created: group A, in which natural healing was achieved; group B, in which porcine xenograft was added; and group C, in which experimental synthetic bone based on hydroxyapatite reinforced with titanium particles was added. Samples were collected at 2 and 4 months postoperatively and analyzed microscopically and histologically. (3) Results: Data were obtained on the healing pattern of the created cavities, as well as the degree of their filling with newly formed bone tissue. Following the results obtained from the stereomicroscope analysis and histological analysis, statistically significant differences were observed between the two biomaterials regarding the time required for the transformation process of the graft particles into bone. Thus, the porcine xenograft was incorporated more quickly into the native bone, while the synthetic bone required a longer period of time. (4) Conclusions: The bone graft materials used acted as scaffolds for the newly formed bone, but each biomaterial required a different amount of time for the particles to be incorporated into the native bone. Full article

Advanced bioengineering, popularly known as regenerative dentistry, has emerged and is steadily developing with the aim of replacement of lost or injured tissues in the mouth using stem cells and other biomaterials. Conventional therapies for reparative dentistry, for instance fillings or crowns, mainly entail the replenishment of affected tissues without much concern given to the regeneration of tissues. However, these methods do not enable the natural function and aesthetics of the teeth to be maintained in the long term. There are several regenerative strategies that offer the potential to address these limitations to the extent of biologically restoring the function of teeth and their components, like pulp, dentin, bone, and periodontal tissues. Hence, stem cells, especially dental tissue derived stem cells, such as dental pulp stem cells, periodontal ligament stem cells, or apical papilla stem cells, are quite promising in this regard. These stem cells have the potentiality of generating precise dental cell lineages and thus are vital for tissue healing and renewal. Further, hydrogels, growth factors, and synthetic scaffolds help in supporting the stem cells for growth, proliferation, and differentiation into functional tissues. This review aims at describing the process of stem cell-based tissue repair biomaterials in dental regeneration, and also looks into the practice and prospects of regenerative dentistry, analysing several case reports and clinical investigations that demonstrate the efficacy and limitations of the technique. Nonetheless, the tremendous potential for regenerative dentistry is a reality that is currently challenged by biological and technical constraints, such as scarcity of stem cell sources, inadequate vascularization, and the integration of the materials used in the procedure. As we move forward, the prospects for regenerative dentistry are in subsequent developments of stem cell technology, biomaterial optimization, and individualized treatment methods, which might become increasingly integrated in dental practices globally. However, there are regulatory, ethical and economic issues that may pose a hurdle in the further advancement of this discipline. Full article

Background/Objectives: Chronic ruptures of the quadriceps and Achilles tendons present significant reconstructive challenges due to factors such as tendon retraction, scar tissue formation, and compromised tissue quality. Traditional repair methods, including V–Y tendinoplasty, autografts, and synthetic scaffolds, often prove inadequate for large or neglected defects. Achilles tendon bone–tendon allografts have emerged as a promising alternative, offering strong fixation, biological incorporation, and sufficient length for bridging extensive gaps. This study aims to document the clinical, radiographic, and MRI outcomes of two challenging cases treated with Achilles tendon bone–tendon allografts and to synthesize these findings within the context of the existing literature to evaluate the broader viability of this reconstructive approach. Methods: An observational analysis was conducted at the Orthopedic and Traumatology Clinic of “Victor Popescu” Military Emergency Hospital in Timișoara, encompassing two patients with chronic, iterative tendon ruptures—one quadriceps tendon rupture and one Achilles tendon rupture. Both patients had previously failed primary repairs, resulting in significant tendon retraction and tissue deficits. Reconstruction was performed using Achilles tendon bone–tendon allografts, involving specific osteotomy techniques for patellar and calcaneal fixation. Postoperative protocols included immobilization followed by structured physiotherapy. Clinical assessments and MRI evaluations were conducted at 8, 12, and 24 weeks postoperatively. Additionally, a comprehensive literature review was performed to compare our findings with existing studies on Achilles bone–tendon allograft utilization in chronic tendon reconstructions. Results: Both patients exhibited substantial improvements in their range of motion and reported low pain levels at the 8- and 12-week follow-ups. MRI assessments indicated well-aligned graft fibers, early bone block integration, and the absence of complications such as re-rupture or infection in the long term. Functional recovery was achieved with complete bone block union and return to normal activities by 24 weeks. The literature review corroborated these outcomes, demonstrating that Achilles tendon bone–tendon allografts provide robust fixation and facilitate biological integration, particularly in cases with large defects and poor tissue quality. Comparative studies highlighted similar functional improvements and graft stability, reinforcing the efficacy of bone–tendon allograft constructs over traditional repair methods in chronic tendon ruptures. Conclusions: Achilles tendon bone–tendon allografts are effective in reconstructing chronic quadriceps and Achilles tendon ruptures, offering robust fixation and facilitating biological integration. These findings, supported by the existing literature, suggest that Achilles bone–tendon allografts are a viable alternative to traditional repair strategies, especially in patients with extensive tendon defects and compromised tissue quality. Further comparative studies are warranted to establish the superiority of bone–tendon allograft constructs over conventional methods. Full article

In recent years, the management of bone defects in regenerative medicine and orthopedic surgery has been the subject of extensive research efforts. The complexity of fractures and bone loss arising from trauma, degenerative conditions, or congenital disorders necessitates innovative therapeutic strategies to promote effective healing. Although bone tissue exhibits an intrinsic regenerative capacity, extensive fractures and critical-sized defects can severely compromise this process, often requiring bone grafts or substitutes. Tissue engineering approaches within regenerative medicine have introduced novel possibilities for addressing nonunions and challenging bone defects refractory to conventional treatment methods. Key components in this field include stem cells, bioactive growth factors, and biocompatible scaffolds, with a strong focus on advancements in bone substitute materials. Both natural and synthetic substitutes present distinct characteristics and applications. Natural grafts—comprising autologous, allogeneic, and xenogeneic materials—offer biological advantages, while synthetic alternatives, including biodegradable and non-biodegradable biomaterials, provide structural versatility and reduced immunogenicity. This review provides a comprehensive analysis of the diverse bone grafting alternatives utilized in orthopedic surgery, emphasizing recent advancements and persistent challenges. By exploring both natural and synthetic bone substitutes, this work offers an in-depth examination of cutting-edge solutions, fostering further research and innovation in the treatment of complex bone defects. Full article

Biopolymer hydrogel-based scaffold materials have received a lot of interest in tissue engineering and regenerative medicine because of their unique characteristics, which include biocompatibility, biodegradability, and the ability to replicate the natural extracellular matrix (ECM). These hydrogels are three-dimensional biopolymer networks that are highly hydrated and provide a supportive, wet environment conducive to cell growth, migration, and differentiation. They are especially useful in applications involving wound healing, cartilage, bone, and soft tissue regeneration. Natural biopolymers such as collagen, chitosan, hyaluronic acid, and alginate are frequently employed as the foundation for hydrogel fabrication, providing benefits such as low toxicity and improved cell adherence. Despite their potential, biopolymer hydrogel scaffolds have various difficulties that prevent broad clinical implementation. Key difficulties include the challenge of balancing mechanical strength and flexibility to meet the needs of various tissues, managing degradation rates to line up with tissue regeneration, and assuring large-scale manufacturing while retaining scaffold uniformity and quality. Furthermore, fostering appropriate vascularization and cell infiltration in larger tissues remains a significant challenge for optimal tissue integration and function. Future developments in biopolymer hydrogel-based scaffolds are likely to concentrate on addressing these obstacles. Strategies such as the creation of hybrid hydrogels that combine natural and synthetic materials, smart hydrogels with stimulus-responsive features, and 3D bioprinting technologies for accurate scaffold production show significant potential. Furthermore, integrating bioactive compounds and growth factors into hydrogel matrices to promote tissue regeneration is critical for enhancing therapeutic results. Full article

Bone tissue engineering has emerged as a promising approach to addressing the limitations of traditional bone grafts for repairing bone defects. This regenerative medicine strategy leverages biomaterials, growth factors, and cells to create a favorable environment for bone regeneration, mimicking the body’s natural healing process. Among the various biomaterials explored, hydrogels (HGs), a class of three-dimensional, hydrophilic polymer networks, have gained significant attention as scaffolds for bone tissue engineering. Thus, this review aimed to investigate the potential of natural and synthetic HGs, and the molecules used for its functionalization, for enhanced bone tissue engineering applications. HGs offer several advantages such as scaffolds, including biocompatibility, biodegradability, tunable mechanical properties, and the ability to encapsulate and deliver bioactive molecules. These properties make them ideal candidates for supporting cell attachment, proliferation, and differentiation, ultimately guiding the formation of new bone tissue. The design and optimization of HG-based scaffolds involve adapting their composition, structure, and mechanical properties to meet the specific requirements of bone regeneration. Current research focuses on incorporating bioactive molecules, such as growth factors and cytokines, into HG scaffolds to further enhance their osteoinductive and osteoconductive properties. Additionally, strategies to improve the mechanical strength and degradation kinetics of HGs are being explored to ensure long-term stability and support for new bone formation. The development of advanced HG-based scaffolds holds great potential for revolutionizing bone tissue engineering and providing effective treatment options for patients with bone defects. Full article

The lack of bone grafts represents a major issue in the orthopedic field, reconstructive surgery, and dentistry. There are several bone conditions that often demand the use of grafts, such as fractures, infections, and bone cancer. The number of bone cancer cases increased in the past few decades and along with it, the need for bone grafting materials. To avoid the use of autografts and allografts there has been an increased interest towards synthetic grafts. This research aims to develop some collagen/hydroxyapatite (Coll/HAp) scaffolds cross-linked with three different agents that could be used in bone tissue engineering (BTE). These scaffolds were obtained with a freeze-drying method after the in situ formation of hydroxyapatite inside the collagen matrix. They were structurally and morphologically characterized and evaluated in terms of antimicrobial activity on E. coli and S. aureus bacterial strains. The results revealed that the scaffolds have porous structures with interconnected pores of suitable dimensions and well-distributed inorganic phases. Coll/HAp samples showed great antibacterial activity even without the use of typically used antibacterial agents. These findings allow us to conclude that these scaffolds are promising candidates for use in BTE and bone cancer treatment after the incorporation of specific antitumoral drugs. Full article

This study focused on the development of a suitable synthetic polymer scaffold for bone tissue engineering applications within the biomedical field. The investigation centered on electrospun polyvinylidene fluoride (PVDF) nanofibers, examining their intrinsic properties and biocompatibility with the human osteosarcoma cell line Saos-2. The influence of oxygen, argon, or combined plasma treatment on the scaffold’s characteristics was explored. A comprehensive design strategy is outlined for the fabrication of a suitable PVDF scaffold, encompassing the optimization of electrospinning parameters with rotating collector and plasma etching conditions to facilitate a subsequent osteoblast cell culture. The proposed methodology involves the fabrication of the PVDF tissue scaffold, followed by a rigorous series of fundamental analyses encompassing the structural integrity, chemical composition, wettability, crystalline phase content, and cell adhesion properties. Full article

Cranio-maxillofacial bone reconstruction, especially for large defects, remains challenging. Synthetic biomimetic materials are emerging as alternatives to autogenous grafts. Tissue engineering aims to create natural tissue-mimicking materials, with calcium phosphate-based scaffolds showing promise for bone regeneration applications. This study developed a porous calcium metaphosphate (CMP) scaffold with physicochemical properties mimicking natural bone, aiming to create a prevascularized synthetic bone graft. The scaffold, fabricated using sintered monocalcium phosphate with poly (vinyl alcohol) as a porogen, exhibited pore sizes ranging from 0 to 400 μm, with the highest frequency between 80 and 100 μm. The co-culture of endothelial cells (ECs) with human alveolar osteoblasts (aHOBs) on the scaffold led to the formation of tube-like structures and intrinsic VEGF release, reaching 10,455.6 pg/mL This level approached the optimal dose for vascular formation. Conversely, the co-culture with mesenchymal stem cells did not yield similar results. Combining ECs and aHOBs in the CMP scaffold offers a promising approach to developing prevascularized grafts for cranio-maxillofacial reconstruction. This innovative strategy can potentially enhance vascularization in large tissue-engineered constructs, addressing a critical limitation in current bone regeneration techniques. The prevascularized synthetic bone graft developed in this study could significantly improve the success rate of maxillofacial reconstructions, offering a viable alternative to autogenous grafts. Full article

In the last thirty years, tissue engineering (TI) has emerged as an alternative method to regenerate tissues and organs and restore their function by implanting specific lineage cells, growth factors, or biomolecules functionalizing a matrix scaffold. Recently, several pathologies have led to bone loss or damage, such as malformations, bone resorption associated with benign or malignant tumors, periodontal disease, traumas, and others in which a discontinuity in tissue integrity is observed. Bone tissue is characterized by different stiffness, mechanical traction, and compression resistance as a function of the different compartments, which can influence susceptibility to injury or destruction. For this reason, research into repairing bone defects began several years ago to find a scaffold to improve bone regeneration. Different techniques can be used to manufacture 3D scaffolds for bone tissue regeneration based on optimizing reproducible scaffolds with a controlled hierarchical porous structure like the extracellular matrix of bone. Additionally, the scaffolds synthesized can facilitate the inclusion of bone or mesenchymal stem cells with growth factors that improve bone osteogenesis, recruiting new cells for the neighborhood to generate an optimal environment for tissue regeneration. In this review, current state-of-the-art scaffold manufacturing based on the use of polycaprolactone (PCL) as a biomaterial for bone tissue regeneration will be described by reporting relevant studies focusing on processing techniques, from traditional—i.e., freeze casting, thermally induced phase separation, gas foaming, solvent casting, and particle leaching—to more recent approaches, such as 3D additive manufacturing (i.e., 3D printing/bioprinting, electrofluid dynamics/electrospinning), as well as integrated techniques. As a function of the used technique, this work aims to offer a comprehensive overview of the benefits/limitations of PCL-based scaffolds in order to establish a relationship between scaffold composition, namely integration of other biomaterial phases’ structural properties (i.e., pore morphology and mechanical properties) and in vivo response. Full article