Composite Scaffolds Research Articles

3D-printed PETG/BC for bone tissue repair

Bone tissue supports the body, enables movement, protects organs, produces blood cells and stores minerals. In regenerative medicine, bone’s natural healing ability drives the need for engineered solutions to treat fractures, defects, and support implants. This study explores the development of poly(ethylene terephthalate glycol) (PETG) and PETG/bacterial cellulose (BC) composite scaffolds with varying BC contents (10, 15, and 20 wt%) for bone tissue engineering. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed porous structures with increasing surface roughness as BC content rose. Water contact angle analysis showed enhanced hydrophilicity in PETG/BC composites, particularly at higher BC levels. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) confirmed successful BC integration and interactions with PETG, along with increased crystallinity. Mechanical testing indicated that compressive strength improved with higher BC content, with 20 wt% BC achieving optimal performance. Biological tests using human adipose-derived stem cells (hADSc) showed enhanced proliferation, differentiation, and mineralization on PETG/BC scaffolds. Among all, the 20 wt% BC scaffold demonstrated the most favorable physical, mechanical, and biological properties. Overall, PETG/BC scaffolds, especially those with 20 wt% BC, show strong potential for future bone tissue engineering applications.

3D-Printing of Electroconductive MXene-Based Micro-Meshes in a Biomimetic Hyaluronic Acid-Based Scaffold Directs and Enhances Electrical Stimulation for Neural Repair Applications.

No effective treatments are currently available for central nervous system neurotrauma although recent advances in electrical stimulation suggest some promise in neural tissue repair. It is hypothesized that structured integration of an electroconductive biomaterial into a tissue engineering scaffold can enhance electroactive signaling for neural regeneration. Electroconductive 2D Ti3C2Tx MXene nanosheets are synthesized from MAX-phase powder, demonstrating excellent biocompatibility with neurons, astrocytes and microglia. To achieve spatially-controlled distribution of these MXenes, melt-electrowriting is used to 3D-print highly-organized PCL micro-meshes with varying fiber spacings (low-, medium-, and high-density), which are functionalized with MXenes to provide highly-tunable electroconductive properties (0.081±0.053-18.87±2.94 S/m). Embedding these electroconductive micro-meshes within a neurotrophic, immunomodulatory hyaluronic acid-based extracellular matrix (ECM) produced a soft, growth-supportive MXene-ECM composite scaffold. Electrical stimulation of neurons seeded on these scaffolds promoted neurite outgrowth, influenced by fiber spacing in the micro-mesh. In a multicellular model of cell behavior, neurospheres stimulated for 7 days on high-density MXene-ECM scaffolds exhibited significantly increased axonal extension and neuronal differentiation, compared to low-density scaffolds and MXene-free controls. The results demonstrate that spatial-organization of electroconductive materials in a neurotrophic scaffold can enhance repair-critical responses to electrical stimulation and that these biomimetic MXene-ECM scaffolds offer a promising new approach to neurotrauma repair.

Magnesium-reinforced PMMA composite scaffolds: Synthesis, characterization, and 3D printing via stereolithography

Abstract Metal particle-reinforced polymer resin scaffolds are becoming increasingly prominent in biomedical applications due to their potential to support tissue regeneration and healing. These scaffolds are designed to serve as temporary frameworks that support affected tissues and gradually degrade during healing. The primary focus of these research efforts has been on determining the optimal materials and methods for creating these scaffolds, ensuring that they are biocompatible, capable of withstanding structural strains, and can support cellular proliferation, tissue growth, and vascularization. Despite the growing interest in polymers and their metal composites, a notable gap exists in leveraging the benefits of fabricating these composites through additive manufacturing techniques, particularly stereolithography (SLA). Magnesium (Mg), in particular, is a biocompatible and osteoconductive material known for its remarkable mechanical properties and biodegradability, making it highly suitable for bone implants. Additionally, Mg can potentially regenerate skin tissues and inhibit bacterial infections. Mg ions are crucial for wound healing because they repair the skin barrier and facilitate blood coagulation. This research focuses on finding optimal conditions for manufacturing magnesium-induced poly(methyl methacrylate) (PMMA) resin scaffolds using SLA. To evaluate their printability and the effect of different material compositions on the 3D-printed structures, PMMA resin was mixed with high-weight percentages (wt%) of Mg alloy WE43. This mixture was then used to 3D-print test coupons and scaffolds via SLA. The impact of Mg incorporation on the scaffold’s structural integrity, thermal degradation, and biological response was assessed through physicochemical and thermal characterization and biocompatibility experiments. Notably, pure PMMA exhibited the highest tensile strength, 26.23 ± 0.14 MPa and an elastic modulus of 707.81 MPa, while PMMA resin/1% Mg showed the lowest strength (19.46 ± 0.25 MPa) and modulus (392.88 MPa), indicating a decrease in mechanical integrity with higher Mg content. However, the thermal stability was enhanced with the addition of Mg as the thermal degradation onset improved from ∼310 to 335°C. The challenges encountered in manufacturing PMMA resin/Mg composites and their potential applications were discussed, highlighting the future directions and promising avenues for further research and development.

Solvothermal Modification Can Impart Hydrophilicity, Antibacterial, and Biocompatibility Properties to Polyurethane Nanofibers: Improvisation by Titanium Dioxide (TiO2) and Silver (Ag) Nanoparticles (NPs)

ABSTRACTThis study focuses on enhancing the wound‐healing properties of polyurethane (PU) nanofibers by improving their hydrophilicity, antibacterial activity, and biocompatibility. The nanofibers were fabricated using electrospinning and subsequently coated with titanium dioxide (TiO2) and silver (Ag) nanoparticles (NPs) through a solvothermal treatment using poly(ethylene glycol) (PEG) as a nonaqueous solvent. FE‐SEM analysis revealed nanofibers exhibited a rougher texture (yielding more surface area) due to the adsorption of NPs. Furthermore, after 3 min, the water contact angle dropped from 92.84° ± 6.57° to 7.67° ± 0.73° for treated nanofibers. The nanofibers were better able to recoup moisture than their pristine counterparts, a necessary criterion for healing. Moreover, the composite mats demonstrated more remarkable thermal stability than pristine nanofibers, with residual weight loss at 700°C being 2.09% for pristine and 24.6% for the composite (7%) nanofibers. The nanofibers were strongly antibacterial compared to the pristine nanofibers, which had no effect. On increasing the concentration of the Ag NPs (7%), the inhibition zones of Escherichia coli were raised from 11.89 ± 0.66 to 14.83 ± 1.04 mm, and that of Staphylococcus aureus from 11.45 ± 0.47 to 14.46 ± 0.50 mm. Cell studies also showed a substantial increase in growth in composite scaffolds compared to pristine nanofibers. Our research presents unique scaffolds that are excellent for improved wound dressing materials.

Uniform Lithium Deposition via Optimization of the Conductive CNT-to-Insulating CaCO3 Ratio for High-Performance Lithium Metal Anodes.

Lithium metal batteries (LMBs) are promising for next-generation energy storage systems due to their high energy density. However, challenges such as uncontrolled lithium dendrite growth and volume expansion of lithium metal anodes (LMAs) limit their practical application, leading to capacity degradation and safety risks. To address these challenges, a composite scaffold combining conductive carbon nanotubes (CNTs) with insulating CaCO3 is being developed. This design enhances lithium-ion adsorption at the electrode surface through the optimized CNT-to-CaCO3 ratio, which increases the local lithium-ion concentration during deposition while balancing conductivity to suppress lithium accumulation typically induced by highly conductive CNTs. Spray pyrolysis is used to fabricate CaCO3 and carbon composite microspheres with multivoid structures (CaCO3/C), designed to fragment into smaller particles, minimizing agglomeration and enabling uniform mixing with CNTs. Among electrodes with varying CNTs-to-CaCO3/C ratios, the electrode having an equal weight ratio of CNTs and CaCO3/C (CNT50-Ca50) exhibits uniform deposition and minimizes volume expansion. In symmetric cells, this electrode demonstrates stable cycling for over 1,200 h at 1.0 mA·cm-2 and a low voltage hysteresis of 110 mV at 10.0 mA·cm-2. In full cells paired with a LiFePO4 cathode, the lithium predeposited CNT50-Ca50 electrode (Li@CNT50-Ca50) delivers 144.0 mAh·g-1 at 1.0 C initially, retaining 80% capacity after 130 cycles with an average Coulombic efficiency of 99.6%.

Comprehensive physicochemical evaluation of 3D‐printed medical‐grade poly(lactic acid)‐based composite: Mechanical, thermal, and morphological properties

Abstract Achieving a high mineral content has become a key focus in the design and additive manufacturing of 3D‐printed biodegradable composite scaffolds to enhance biodegradation, osteoconductivity, and mechanical performance. However, the effects under simulated physiological conditions, such as temperature and hydration, which are important considerations from an implant design perspective, on these composites are not well understood. In this study, we employed medical‐grade composite filaments consisting of 60% Lactoprene and 40% β‐tricalcium phosphate (β‐TCP) to 3D print scaffolds. We used various analytical techniques to characterize these scaffolds under simulated physiological conditions, including morphological, physicochemical, and thermomechanical analyses. The composite exhibited a glass transition temperature of 28°C, which significantly reduced its mechanical properties under physiological conditions. Interestingly, when gamma irradiation was used for sterilization, the compressive modulus increased by approximately 17 times, reaching 106.5 MPa. The composite also demonstrated notable recovery behavior, particularly in hydrated samples at 37°C, indicating hyperelastic characteristics. Our results highlight the importance of studying the hydration water in high‐ceramic‐content scaffold composites. We provided insights into the molecular interactions between ceramic materials, polymers, and water. This study underscores the necessity of testing composite scaffolds under physiological conditions and supports future research on the degradation behavior and in vivo testing of polymers reinforced with osteogenic fillers for scaffold‐guided bone regeneration.

Clay-reinforced polyvinyl alcohol/sodium alginate /hydroxyapatite scaffolds: Quorum sensing inhibition and enhanced osteoblast attachment for bone tissue engineering.

Clay-reinforced polyvinyl alcohol/sodium alginate /hydroxyapatite scaffolds: Quorum sensing inhibition and enhanced osteoblast attachment for bone tissue engineering.

3D-Printed Polycaprolactone Scaffolds Reinforced with Cellulose Nanocrystals and Silver Nanoparticles for Bone Tissue Engineering.

Cellulose nanocrystals (CNC) have garnered significant attention in pharmaceutical and medical applications due to their biocompatibility, biodegradability, renewability, and strong surface reactivity. In this study, we designed 3D-printed bioactive composite scaffolds via fused deposition modeling (FDM), incorporating polycaprolactone (PCL), CNC derived from Ficus thonningii bark, and silver nanoparticles (AgNps) synthesized through in situ reduction of silver nitrate AgNO3. Energy-dispersive X-ray spectroscopy (EDX) confirmed AgNps incorporation, while scanning electron microscopy (SEM) revealed a highly porous, interconnected structure. The inclusion of CNC and AgNps enhanced PCL's biodegradability, hydrophilicity, and hydroxyapatite nucleation, all crucial for osteoconductivity. The scaffolds demonstrated mechanical properties suitable for bone regeneration, effective antibacterial activity against Escherichia coli, and cytocompatibility with Mesenchymal Stem Cells (MSCs). These findings highlight the potential of PCL/CNCx/AgNps scaffolds as advanced biomaterials for bone tissue engineering, since they offer enhanced resorbability, antibacterial protection, and structural adaptability.

Near-infrared light and magnetic field dual-responsive 3D printed scaffolds for sequential treatment of infected bone defects.

The treatment of infected bone defects remains a challenge due to the complex biological processes involved, including antibacterial, anti-inflammatory, angiogenesis and bone regeneration. Polyetherimide (PEI) has promising applications in orthopaedics, but its biological inertness limits its clinical efficacy. In this study, a smart near-infrared (NIR) light and magnetic field responsive 3D printed scaffold was developed by combining PEI and Fe3O4 nanoparticles. Gelatin methacrylate (GelMA) hydrogel containing aloe-emodin (AE), a natural antimicrobial and antioxidant compound, was subsequently injected into the 3D printed scaffold to create the P-Fe3O4@GM-AE composite scaffold. This composite scaffold exhibited several key functionalities: First, it effectively eliminated methicillin-resistant Staphylococcus aureus (MRSA) when exposed to NIR light, achieving an in vivo antimicrobial rate of 99.97 ± 0.1%. Secondly, it effectively removed reactive oxygen species (ROS) and prevented the pro-inflammatory M1 polarization of macrophages in the infected bone defect microenvironment, creating favourable conditions for bone reconstruction. Moreover, during the reconstruction stage, the magnetic composite scaffold, when combined with a static magnetic field, promoted osteogenesis-angiogenesis coupling, thereby accelerating bone repair. Thus, this study provides new insights and methods for the sequential treatment of infected bone defects.

In vitro and in vivo evaluations of Loofah (Luffa cylindrica) micro- and PHBV nanofiber-integrated hydrogel scaffolds for meniscus regeneration

This study focuses on developing a composite hydrogel scaffold for meniscus regeneration by integrating loofah (Luffa cylindrica) microfibers and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers as cell adhesion sites and mechanical reinforcements into a biomimetic collagen/chitosan matrix Scaffolds were chemically cross-linked with a natural cross-linker genipin (0.1%, 0.3%, 0.5%) and fabricated via freeze-drying to achieve optimal porosity and mechanical stability. The 0.3% genipin-cross-linked composite hydrogel scaffold (PL/ChtCol-3) demonstrated the highest compressive strength, damping capacity, and water absorption, and was selected for biocompatibility evaluation. In vitro studies using rabbit bone marrow-derived mesenchymal stem cells (rMSCs) confirmed the scaffold’s nontoxicity and biocompatibility, promoting cell attachment, proliferation, and type II collagen expression. In vivo analysis was conducted using a standardized meniscus defect model in 24 New Zealand rabbits, divided into three groups: empty defect, cell-free scaffold, and cell-laden scaffold. Postimplantation assessments, including Micro-CT, biomechanical, histological, and immunohistochemical analyses showed that the cell-laden PL/ChtCol-3 scaffold significantly enhanced meniscus regeneration. Notably, it reduced defect volume and restored compressive modulus to levels comparable with native tissue. These findings demonstrate that the PL/ChtCol-3 scaffold, particularly when combined with rMSCs, holds strong potential as a biomimetic and regenerative platform for meniscus tissue engineering.Graphical abstract

Fabrication of hierarchical porous DEGDA/hydroxyapatite composite scaffolds with biocompatibility via DLP 3D printing for enhanced mechanical strength

Fabrication of hierarchical porous DEGDA/hydroxyapatite composite scaffolds with biocompatibility via DLP 3D printing for enhanced mechanical strength

Gelatin-hydroxyapatite based hybrid composites: Enhanced mechanical and biological characteristics through biomaterials integration for bone tissue engineering applications.

Gelatin-hydroxyapatite based hybrid composites: Enhanced mechanical and biological characteristics through biomaterials integration for bone tissue engineering applications.

Nanobioactive glass/chitosan/collagen composite loaded with methylene blue for tissue regeneration and bacterial infection treatment by photodynamic therapy.

Nanobioactive glass/chitosan/collagen composite loaded with methylene blue for tissue regeneration and bacterial infection treatment by photodynamic therapy.

Modulating immune-stem cell crosstalk enables robust bone regeneration via tuning compositions of macroporous scaffolds

Following bone injury, macrophages (Mφ) initiate the immune response by secreting signals that recruit mesenchymal stem cells (MSC) and other niche cells to shape healing. Despite its importance, the potential of enhancing bone regeneration by modulating immune-stem cell crosstalk is largely unexplored. Here, we report a macroporous microribbon (µRB) scaffold with tunable ratios of gelatin (Gel) and chondroitin sulfate (CS), achieving rapid endogenous bone regeneration in a critical-sized defect model without exogenous growth factors or cells. The 3D MSC/Mφ co-culture model, but not the mono-culture model, effectively identified Gel50_CS50 as the leading ratio for accelerating bone regeneration in vivo. Single-cell sequencing (scRNAseq) and CellChat analysis revealed that Gel50_CS50 significantly enhanced the cellular crosstalk among Mφ and other bone niche cell types, with signaling pathways linked to anti-inflammation, angiogenesis, and osteogenesis. This study demonstrates Gel50_CS50 µRB as a promising biomaterial-based therapy for treating critical-sized bone defects by modulating cellular crosstalk.

Antibacterial bone defect repair via PCL/PLGA/HA/MgO NPs composite scaffolds

Antibacterial bone defect repair via PCL/PLGA/HA/MgO NPs composite scaffolds

Near-infrared light triggered bio-inspired enhanced natural silk fibroin nanofiber composite scaffold for photothermal therapy of periodontitis.

Near-infrared light triggered bio-inspired enhanced natural silk fibroin nanofiber composite scaffold for photothermal therapy of periodontitis.

Cooling rate effects on non-isothermal crystallization and mechanical behaviors of poly-ether-ether-ketone/bioactive glass composite scaffolds fabricated by laser powder bed fusion

Cooling rate effects on non-isothermal crystallization and mechanical behaviors of poly-ether-ether-ketone/bioactive glass composite scaffolds fabricated by laser powder bed fusion

3D collagen nanofiber scaffold with adipose derived stem cells for functional adipose tissue regeneration

Adipose tissue engineering offers a promising approach for breast reconstruction, yet achieving efficient adipose regeneration remains challenging due to poor cell survival and tissue integration. Hence, we developed a three-dimensional (3D) electrospun collagen nanofiber scaffold integrated with adipose-derived mesenchymal stem cells (ADSCs), designed to enhance adipose tissue regeneration by providing a biomimetic extracellular matrix environment. The incorporation of collagen nanofibers enhances cell adhesion and extracellular matrix remodeling, further promoting adipogenic differentiation. Compared to conventional two-dimensional (2D) culture, ADSCs seeded on the scaffold exhibit significantly improved viability and lipid accumulation. In vivo implantation in a rat model demonstrated that the COL-ADSCs composite scaffold increased subcutaneous fat thickness from 2.69 ± 0.10 mm to 3.37 ± 0.11 mm over four weeks, while also promoting collagen remodeling and angiogenesis, as confirmed by CD31-positive staining. Despite these promising outcomes, this study is limited to a small animal model, and further validation in large animal models and clinical settings is necessary. These findings indicate that the COL-ADSCs composite scaffold provides a biomimetic microenvironment that supports ADSC adhesion, differentiation, and tissue remodeling, highlighting its potential as a clinically applicable biomaterial for breast reconstruction.

Bioactive Glass Incorporated Silk-Gelatin Composite Scaffold for Bone Tissue Engineering

Bioactive Glass Incorporated Silk-Gelatin Composite Scaffold for Bone Tissue Engineering

3D-printed titanium dioxide-reinforced calcium silicate composite scaffold promotes efficient bone defect repair through activation of osteogenic and angiogenic differentiation

3D-printed titanium dioxide-reinforced calcium silicate composite scaffold promotes efficient bone defect repair through activation of osteogenic and angiogenic differentiation