3D-printed Scaffolds Research Articles

3D Printing of Stiff, Tough, and ROS-Scavenging Nanocomposite Hydrogel Scaffold for in Situ Corneal Repair

Despite significant advancements in hydrogels in recent years, their application in corneal repair remains limited by several challenges, including unfitted curvatures, inferior mechanical properties, and insufficient reactive oxygen species (ROS)-scavenging activities. To address these issues, this study introduces a 3D-printed corneal scaffold with nanocomposite hydrogel consisting of gelatin methacrylate (GelMA), poly (ethylene glycol) diacrylate (PEGDA), Laponite, and dopamine. GelMA and PEGDA act as matrix materials with photo-crosslinking abilities. As a two-dimensional nanoclay, Laponite enhances the rheological properties of the hydrogel, making it suitable for 3D printing. Dopamine self-polymerizes into polydopamine (PDA), providing the hydrogel with ROS-scavenging activity. The incorporation of Laponite and the synergistic effect of PDA endow the hydrogel with good mechanical properties. In vitro investigations demonstrated the cytocompatibility of GelMA-PEGDA-Laponite-dopamine (GPLD) hydrogel and its ROS-scavenging activity. Furthermore, in vivo experiments using a rabbit model of lamellar keratoplasty showed accelerated corneal re-epithelialization and complete stromal repair after the implantation of the 3D-printed scaffold. Overall, due to its high bioactivity and simple preparation, the 3D-printed scaffold using GPLD hydrogel offers an alternative for corneal repair with potential for clinical translation. Statement of Significance: The clinical application of hydrogel corneal scaffolds has been constrained by their inadequate mechanical properties and the complex microenvironment created by elevated levels of reactive oxygen species (ROS) post-transplantation. In this study, we developed a kind of nanocomposite hydrogel by integrating Laponite and dopamine into GelMA and PEGDA. This advanced hydrogel was utilized to 3D print a corneal scaffold with high mechanical strength and ROS-scavenging abilities. When applied to a rabbit model of lamellar keratoplasty, the 3D-printed scaffold enabled complete re-epithelialization of the cornea within a week. Three months after surgery, the corneal stroma was fully repaired, and regeneration of corneal nerve fibers was also observed. This 3D-printed scaffold demonstrated exceptional efficacy in repairing corneal defects with potential for clinical translation.

Amyloid Nanofilm-Induced surface mineralization of 3D-Printed Polyetheretherketone scaffolds for in situ orbital bone regeneration and repair

Orbital bone defect repair is both challenging and crucial and requires the comprehensive consideration of anatomical complexity, functional preservation, aesthetic outcomes, postoperative risks, and long-term effects. Polyetheretherketone (PEEK) is a promising orthopedic substitute material due to its cortical bone-like elastic modulus, biocompatibility, chemical stability, and natural radiolucency. However, PEEK is bioinert and lacks interfacial bioactivity, which limits its ability to promote bone growth and osseointegration. In this study, we fabricated porous PEEK scaffolds using Fused Deposition Modeling (FDM) 3D printing technology. We employed a phase-transitioned lysozyme (PTL) nanofilm as the organic matrix template to construct a robust hydroxyapatite (HAp) coating both inside and outside the porous PEEK scaffold, generating HAp@PTL@PO-PEEK. The PTL nanofilm acted as a strong glue, enhancing the interfacial bonding strength between the HAp coating and PEEK. In vitro cell biology experiments revealed that HAp@PTL@PO-PEEK promoted the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells. Furthermore, the modified scaffolds exhibited excellent osteoconductivity and osteoinductivity in the in vivo repair of rabbit orbital bone defects, promoting new bone formation and guiding new bone growth into the scaffold. Therefore, HAp@PTL@PO-PEEK scaffolds hold potential for clinical craniomaxillofacial bone regeneration and repair.

Enhanced mechanical strength and bioactivity of 3D-printed β-TCP scaffolds coated with bioactive glasses

Enhanced mechanical strength and bioactivity of 3D-printed β-TCP scaffolds coated with bioactive glasses

Optimization of chitosan-gelatin-based 3D-printed scaffolds for tissue engineering and drug delivery applications

The combination of biocompatible materials and advanced three-dimensional (3D) additive manufacturing technologies holds great potential in the development of finely tuned complex scaffolds with reproducible macro- and micro-structural characteristics for biomedical applications, such as tissue engineering and drug delivery. In this study, biocompatible printable inks based on chitosan, collagen and gelatin were developed and 3D-printed with a pneumatic-based extrusion printer. The printability of various chitosan–gelatin (CS-Gel) hydrogel inks was assessed by evaluating the quality of the printed constructs. The inks required an extrusion pressure of 150 ± 40 MPa with G22 and G25 nozzles for optimal printing. Inks with low chitosan concentrations (<4% w/v) exhibited poor printability, while inks with 4 % w/v chitosan and 1 % w/v gelatin (CG) demonstrated satisfactory extrusion and printing quality. The addition of collagen (0.1 % w/v) to the optimized ink (CGC) did not compromise printability. Post-printing stabilization using KOH produced self-supporting scaffolds with consistent morphological integrity, while weaker bases like NaOH/EtOH and ammonia vapors resulted in lower pore sizes and reduced structural stability. Water evaporation studies showed that neutralized samples had slower evaporation rates due to the strong intermolecular interactions formed during the neutralization process, contributing to a stable crosslinked network. FTIR spectra confirmed the formation of polyelectrolyte complexes in the CS-Gel and CS-Gel-Collagen blends, further enhancing structural stability. Swelling tests indicated that neutralized constructs maintained stability in different pH environments, with KOH-treated samples exhibiting the lowest swelling ratios and the highest structural stability. After optimizing the ink composition, 10 wt% Levofloxacin was loaded in the constructs as a model antibiotic and it’s in vitro release rate was quantified. Drug loading was approximately 4 % for both ink compositions GC and CGC. CG Levo released over 80 % of levofloxacin within the first hour, reaching full release in 24 h, indicating inadequate control, while CGK Levo exhibited slower initial release (55 % in 15 min) followed by stabilized release after 4 h, likely due to controlled diffusion from expanded constructs. These findings demonstrate that the developed hydrogel inks and optimized printing parameters can produce scaffolds suitable for tissue engineering applications. Finally, the cell compatibility of the 3D-printed constructs was confirmed with MTT assay on fibroblasts and the antimicrobial activity of the drug-loaded constructs was tested against E. coli and S. aureus, showing an increase of the bacteria free zone from 8 ± 0.4 mm of the control against E. coli up to 16.4 ± 0.37 mm in the presence of the KOH-treated CG Levo printed construct.

Bone regeneration in rabbit cranial defects: 3D printed polylactic acid scaffolds gradually enriched with marine bioderived calcium phosphate

ObjectiveThis study aimed to evaluate the in vivo biocompatibility, mechanical performance and osteoconductive potential of 3D-printed polylactic acid (PLA) scaffolds enriched with marine bioderived calcium phosphate (bioCaP) for bone tissue engineering. Materials and MethodsPLA-bioCaP composite scaffolds were specifically designed for the rabbit cranial defect model by 3D printing, with a uniform distribution of open square-shaped pores and contributions in bioCaP. Physicochemical and mechanical characterization and the evaluation of biological response are presented. ResultsThe scaffolds demonstrated mechanical properties comparable to human bones, integration with the host bone, and osteoconductive behavior promoting cell ingrowth from the defect edge. Strong mineralized tissue ingrowth through the scaffolds’ pores was observed, providing notable support to the host bone. In quantitative terms, micro-CT and histomorphometry analysis post-implantation revealed no significant differences in bone regeneration across all groups. ConclusionThe 3D-printed scaffolds with perpendicular patterning, open porosity, and proposed composition displayed satisfactory mechanical properties, biocompatibility, and osteoconductive response. The scaffolds promoted bone regeneration at similar levels as the PLA. The highest contribution of bioCaP promoted a positive influence in certain histomorphometric parameters; however, it did not significantly improve their osteogenic capability. Further research is required to optimize scaffold composition and enhance their osteogenic potential. Clinical RelevanceThis study presents a significant advancement in bone tissue engineering through the development of personalized composite scaffolds for bone-related applications. The clinical implications of this research are profound, especially considering the increasing demand for functional bone regeneration technologies capable of producing cost-effective producing cost-effective customized scaffolds.

Construction of lightweight, high-energy absorption 3D-printed scaffold for electromagnetic interference shielding with low reflection

The pursuit of advanced electromagnetic interference (EMI) shielding materials, featuring lightweight, programmable structures, low reflection, and essential mechanical properties, presents both promise and challenge. In this study, a scaffold based on triply periodic minimal surface (TPMS) with 70 % porosity was designed using 3D printing technology, showcasing enhanced compressive strength and impressive energy absorption capacity. Building upon this scaffold, the monolithic layered dipping method served as an innovative strategy to easily regulate gradient distribution of carbon nanotube (CNT) on 3D-printed scaffold and ensured their integrity. Moreover, the gradient conductive 3D-printed scaffold, with a rational CNT distribution, features a dramatically reduced reflection power coefficient of 0.13, achieving an EMI shielding effectiveness (SE) up to 35.9 dB, indicating that 99.99 % of EM waves are blocked upon penetration. Finite element analysis (FEA) justifies that the 3D-printed scaffold with increased gradient CNT content was more effective in absorbing EM waves, highlighting its remarkable design flexibility and practical feasibility of gradient conductive structure. Furthermore, we analyze the EM waves attenuation mechanism of gradient conductive 3D-printed scaffold, facilitated by introduces multiple loss mechanisms, which effectively establishing an "absorption-reflection-reabsorption" process for dissipating EM waves. This work is expected to open new avenues in the field of FDM 3D printing technology in the fabrication of low reflection EMI composites.

Copper-Loaded Microporous Chitosan Generated within a 3D-Printed Polylactic Acid-Pearl Scaffold: Structure and Performance

Copper-Loaded Microporous Chitosan Generated within a 3D-Printed Polylactic Acid-Pearl Scaffold: Structure and Performance

Development of Soft Wrinkled Micropatterns on the Surface of 3D-Printed Hydrogel-Based Scaffolds via High-Resolution Digital Light Processing

The preparation of sophisticated hierarchically structured and cytocompatible hydrogel scaffolds is presented. For this purpose, a photosensitive resin was developed, printability was evaluated, and the optimal conditions for 3D printing were investigated. The design and fabrication by additive manufacturing of tailor-made porous scaffolds were combined with the formation of surface wrinkled micropatterns. This enabled the combination of micrometer-sized channels (100–200 microns) with microstructured wrinkled surfaces (1–3 μm wavelength). The internal pore structure was found to play a critical role in the mechanical properties. More precisely, the TPMS structure with a zero local curvature appears to be an excellent candidate for maintaining its mechanical resistance to compression stress, thus retaining its structural integrity upon large uniaxial deformations up to 70%. Finally, the washing conditions selected enabled us to produce noncytotoxic materials, as evidenced by experiments using AlamarBlue to follow the metabolic activity of the cells.

Design and In Vivo Testing of an Anatomic 3D-Printed Peripheral Nerve Conduit in a Rat Sciatic Nerve Model.

Background: Three-dimensional (3D) printer technology has seen a surge in use in medicine, particularly in orthopedics. A recent area of research is its use in peripheral nerve repair, which often requires a graft or conduit to bridge segmental defects. Currently, nerve gaps are bridged using autografts, allografts, or synthetic conduits. Purpose: We sought to improve upon the current design of simple hollow, cylindrical conduits that often result in poor nerve regeneration. Previous attempts were made at reducing axonal dispersion with the use of multichanneled conduits. To our knowledge, none has attempted to mimic and test the anatomical topography of the nerve. Methods: Using serial histology sections, 3D reconstruction software, and computer-aided design, a scaffold was created based on the fascicular topography of a rat sciatic nerve. A 3D printer produced both cylindrical conduits and topography-based scaffolds. These were implanted in 12 Lewis rats: 6 rats with the topographical scaffold and 6 rats with the cylindrical conduit. Each rodent's uninjured contralateral limb was used as a control for comparison of functional and histologic outcomes. Walking track analysis was performed, and the Sciatic Functional Index (SFI) was calculated with the Image J software. After 6 weeks, rats were sacrificed and analyses performed on the regenerated nerve tissue. Primary outcomes measured included nerve (fiber) density, nerve fiber width, total number of nerve fibers, G-ratio (ratio of axon width to total fiber width), and percent debris. Secondary outcomes measured included electrophysiology studies of electromyography (EMG) latency and EMG amplitude and isometric force output by the gastrocnemius and tibialis anterior. Results: There were no differences observed between the cylindrical conduit and topographical scaffold in terms of histological outcomes, muscle force, EMG, or SFI. Conclusion: This study of regeneration of the sciatic nerve in a rat model suggests the feasibility of 3D-printed topographical scaffolds. More research is required to quantify the functional outcomes of this technology for peripheral nerve regeneration.

3D-printing of dipyridamole/thermoplastic polyurethane materials for bone regeneration.

Tissue engineering combines biology and engineering to develop constructs for repairing or replacing damaged tissues. Over the last few years, this field has seen significant advancements, particularly in bone tissue engineering. 3D printing has revolutionised this field, allowing the fabrication of patient- or defect-specific scaffolds to enhance bone regeneration, thus providing a personalised approach that offers unique control over the shape, size, and structure of 3D-printed constructs. Accordingly, thermoplastic polyurethane (TPU)-based 3D-printed scaffolds loaded with dipyridamole (DIP) were manufactured to evaluate their in vitro osteogenic capacity. The fabricated DIP-loaded TPU-based scaffolds were fully characterised, and their physical and mechanical properties analysed. Moreover, the DIP release profile, the biocompatibility of scaffolds with murine calvaria-derived pre-osteoblastic cells, and the intracellular alkaline phosphatase (ALP) assay to verify osteogenic ability were evaluated. The results suggested that these materials offered an attractive option for preparing bone scaffolds due to their mechanical properties. Indeed, the addition of DIP in concentrations up to 10% did not influence the compression modulus. Moreover, DIP-loaded scaffolds containing the highest DIP cargo (10% w/w) were able to provide sustained drug release for up to 30 days. Furthermore, cell viability, proliferation, and osteogenesis of MC3T3-E1 cells were significantly increased with the highest DIP cargo (10% w/w) compared to the control samples. These promising results suggest that DIP-loaded TPU-based scaffolds may enhance bone regeneration. Combined with the flexibility of 3D printing, this approach has the potential to enable the creation of customized scaffolds tailored to patients' needs at the point of care in the future.

Efficacy of 3D-printed chitosan‑cerium oxide dressings coated with vancomycin-loaded alginate for chronic wounds management

Multifunctional wound dressings with antibacterial and antioxidant properties hold significant promise for treating chronic wounds; however, achieving a balance of these characteristics while maintaining biocompatibility is challenging. To enhance this balance, this study focuses on the design and development of 3D-printed chitosan-matrix composite scaffolds, which are incorporated with varying amounts of cerium oxide nanoparticles (0, 1, 3, 5, and 7 wt%) and subsequently coated with a vancomycin-loaded alginate layer. The structure, antibiotic drug delivery kinetics, biodegradation, swelling, biocompatibility, antibacterial, antioxidant, and cell migration behaviors of the fabricated dressings were evaluated in-vitro. The findings reveal that all of the formulations demonstrated a robust antibacterial effect against S. aureus bacterial strains in disk diffusion tests. Furthermore, the dressings containing cerium oxide nanoparticles exhibited proper antioxidant capabilities, with over 78.1 % reactive oxygen species (ROS) scavenging efficiency achieved with 7 % cerium oxide nanoparticles. The sample containing 5 % cerium oxide nanoparticles was identified as the optimal formulation, characterized by the most favorable cell biocompatibility, an ROS scavenging ability of over 73.4 %, and the potential to close the wound bed within 24 h. This study highlights that these dressings are promising for managing chronic wounds by preventing infection and oxidative stress in a correct therapeutic sequence.

Cartilage Tissue Construct from Human Adipose-Derived Mesenchymal Stem Cells on 3D-Printed Polylactic Acid Scaffold

Cartilage Tissue Construct from Human Adipose-Derived Mesenchymal Stem Cells on 3D-Printed Polylactic Acid Scaffold

Ionic substitution through bredigite doping for microstructure and performance adjustment in DLP 3D-printed TPMS porous HA bone scaffolds

ABSTRACT Hydroxyapatite (HA) is widely used in bone scaffold development, but still faces problems of forming difficulty, slow degradation, and limited biological performance. In this study, triply periodic minimal surface (TPMS) porous HA scaffolds were prepared using desktop-level DLP and then doped with bredigite (BR) to enhance their performance through ion substitution to adjust microstructure. The DLP-prepared scaffolds displayed intricate curved surface porous structure, and their micro-porosity decreased while grain size increased with sintering holding time. During sintering, Mg2+ from BR substituted Ca2+ in HA, forming new secondary phases, which slightly decreased grain size while significantly increased micro-porosity. These factors slightly reduced mechanical properties while significantly enhanced degradation. The rapid release of inorganic active ions from BR and new phases enhanced the biomineralization and cell response. This study demonstrated the potential of using desktop-level DLP to construct complex porous ceramic scaffolds and using ion substitution to modulate their microstructure and performance.

3D Printing Hierarchical Porous Nanofibrous Scaffold for Bone Regeneration.

Current limitations in 3D printing pose significant challenges for the fabrication of hierarchical 3D scaffolds with nanofibrous structures that simulate the natural bone extracellular matrix (ECM) for enhanced bone regeneration. This study presents an innovative approach to 3D printing customized hierarchical porous scaffolds with nanofiber structures using biodegradable nanofibrous microspheres as the bio-ink. In vitro investigations demonstrate that the hierarchical porous architecture substantially enhances cell infiltration and proliferation rates, while the nanofiber topology provides physical cues to guide osteogenic differentiation and ECM deposition. When serving as a cell carrier, the 3D-printed nanofibrous scaffold promotes bone tissue regeneration and integration in vivo. Additionally, the facile and versatile chemical modification facilitates the precise tailoring of the scaffold's functionality. Using nanofibrous microspheres with highly biomimetic and versatile modification properties as the foundational constituent in this universal 3D printing methodology enables comprehensive manipulation of scaffolding biological properties, spanning from macroscopic external morphology to molecular-scale biochemical kinetics, thereby addressing a diverse spectrum of clinical requisites.

Antibacterial bioadaptive scaffold promotes vascularized bone regeneration by synergistical action of intrinsic stimulation and immunomodulatory activity

The coupling of angiogenesis and osteogenesis is the fundamental necessity in bone fracture healing, thus simulative action of tissue-engineered bone provides powerful and beneficial effects in the treatment of bone defect. Herein, an immunoregulatory biocomposite scaffold with intrinsic activities of coupling angiogenesis and osteogenesis was constructed based on polyelectrolytes-modified 3D-printed scaffold for enhanced bone regeneration. The doping of Sr-doped hydroxyapatite (SrHA) within 3D-printed polycaprolactone (PCL) scaffold and subsequent slit guidance ligand 3 (SLIT3) protein adsorption through surface coating of carboxymethyl chitosan (CCS)/hyperbranched polylysine (HBPL) achieved on-demand delivery of SLIT3 and Sr ions. The antibacterial property of polyelectrolytes-modified scaffold was characterized and was directly proportional to the layer number of polyelectrolytes coating. The dual-factor delivery scaffold had good biocompatibility to support cell proliferation and migration, and was capable of stimulating angiogenesis and osteogenesis by intrinsic stimulation from released SLIT3 protein and Sr ions. Importantly, the multifunctional scaffold had immunomodulatory effects of promoting M2-type polarization of macrophages and thereby increasing anti-inflammatory factors level, as well as indirectly promoting angiogenesis and osteogenesis. The in vivo experiments revealed that the anti-inflammatory effect was significantly reinforced for providing a better regenerative microenvironment and bone regeneration capacity was dramatically enhanced accompanied with type H vessels formation when implanted with multifunctional scaffold. Therefore, the bioadaptive scaffold possessed amplified bone regeneration performance through intrinsic stimulation and immunomodulatory effects, suggesting a promising therapeutic candidate for bone defect repair.

Micro-thin hydrogel coating integrated in 3D printing for spatiotemporal delivery of bioactive small molecules

Three-dimensional (3D) printing incorporated with controlled delivery is an effective tool for complex tissue regeneration. Here, we explored a new strategy for spatiotemporal delivery of bioactive cues by establishing a precise-controlled micro-thin coating of hydrogel carriers on 3D-printed scaffolds. We optimized the printing parameters for three hydrogel carriers, fibrin cross-linked with genipin, methacrylate hyaluronic acid, and multidomain peptides, resulting in homogenous micro-coating on desired locations in 3D printed polycaprolactone microfibers at each layer. Using the optimized multi-head printing technique, we successfully established spatial-controlled micro-thin coating of hydrogel layers containing profibrogenic small molecules (SMs), Oxotremorine M and PPBP maleate, and a chondrogenic cue, Kartogenin. The delivered SMs showed sustained releases up to 28 d and guided regional differentiation of mesenchymal stem cells, thus leading to fibrous and cartilaginous tissue matrix formation at designated scaffold regionsin vitroandin vivo. Our micro-coating of hydrogel carriers may serve as an efficient approach to achieve spatiotemporal delivery of various bioactive cues through 3D printed scaffolds for engineering complex tissues.

DNAR-04. TUMOUR TREATING FIELDS (TTFIELDS) AND DNA DAMAGE RESPONSE (DDR) INHIBITORS ENHANCE GLIOMA CELL DEATH THROUGH CHEMO-/RADIOSENSITISATION

Abstract High grade gliomas are the most common primary brain cancer malignancies with ~300,000 global diagnoses each year with glioblastomas (WHO grade IV) conferring the worst prognoses. This arises from their treatment resistance, rationalised by the presence of glioma stem cell-like (GSC) tumour sub-regions and high intratumoural spatio-heterogeneity. TTFields are clinically approved alternating electric fields of intermediate frequency that exert anti-mitotic effects and invoke downregulation of the DDR. Therefore, TTFields alongside clinically developed, and blood brain barrier (BBB) penetrating DDR inhibitors (DDRi) could boost cell death and overcome treatment resistance through chemo-/radiosensitisation. Primary GSC cell lines were derived from surgically resected and clinically defined tumour core and invasive edge regions and grown in more biologically relevant 3D-printed AlvetexTM scaffolds, offering highly clinically relevant models. Cells were then pre-treated with DDRi, subjected to chemo-/radiotherapy and then incubated under TTFields (200 kHz, 72 hrs) with their survival measured by clonogenic assays after 3 weeks. Immunofluorescence and western blot analysis were used to analyse the combination treatment effects on the DDR. In multiple 3D-grown core/edge GSC models, western blot analyses revealed that the DDR was altered by TTFields and clonogenic survival assays revealed that TTFields alongside DDRi led to significant chemo-/radiosensitisation. TTFields alongside DDRi effectively enhances cell death by significant treatment sensitisation effects in clinically relevant 3D GSCs which exhibit extensive intra and intertumoral spatio-heterogeneity. Given that all the DDRi used are BBB penetrable and are either clinically approved or in clinical trials, TTFields could additionally compliment these treatment regimens in gliomas to boost their efficacy.

3D-Printed Gelatin-Based Scaffold Crosslinked by Genipin: Evaluation of Mechanical Properties and Biological Effect.

In this study, scaffolds based on natural polymer gelatin A, blended with polyvinylpyrrolidone were crosslinked by genipin (0.5 and 1 wt%), in order to investigate their mechanical performance and potential for biomedical application. Semi-solid extrusion (SSE) 3D printing technique was used, enabling insitu crosslinking of the blend during processing. Swelling test showed that the swelling ratio reduces with higher concentration of genipin due to an increased crosslinking. The FTIR analysis confirmed the crosslinking of scaffolds by genipin. DSC analysis and mechanical testing have shown improved thermal and mechanical properties. Morphological analysis of scaffolds by FESEM showed increased toughening of the material with the crosslinking. Tensile strength and microhardness showed a significant rise in scaffolds with the increase in genipin content, which was up to 93.8% and 125.3%, respectively. These findings were in accordance with morphological features present in samples. The biological effect of the scaffold matrix system was evaluated by qualitative and quantitative cytotoxicity assessment invitro, demonstrating the absence of cytotoxicity in tested preparations in a direct test. The cytotoxicity index based on the metabolic activity of cells in an indirect test showed up to 20% reduction of viability compared with the control, confirming the absence of cytotoxicity, which was additionally verified by propidium iodine staining of the cells exposed to scaffolds. The presented gelatin-based crosslinked scaffolds obtained by 3D printing represent good candidates for biomedical application and future research that includes further invitro and invivo analysis.

3D-Printed Bifunctional Scaffold for Treatment of Critical Bone Defects Based on Osteoimmune Microenvironment Regulation and Osteogenetic Effects.

The critical-sized bone defect resulting from trauma, tumor resection, and congenital deformity fails to undergo spontaneous healing due to its substantial size, while the ensuing inflammatory process and hypoxic environment further impede the regenerative process. Therefore, it has consistently presented a significant clinical challenge. In the present study, we incorporate a glycyrrhizic acid (GA)-functionalized hydrogel onto the surface of a Hydroxyapatite (Hap)-modified Polycaprolactone (PCL) scaffold to fabricate a composite scaffold. The composed scaffold showed favorable anti-inflammatory and antioxidative capabilities by modulating macrophage polarization and scavenging reactive oxygen species (ROS); the modification of Hap enhanced its osteogenic ability. An in vivo rat skull defect model confirmed that the composed scaffold efficiently promotes bone regeneration. In general, the composed scaffold with the ability of osteoimmune microenvironment regulation can effectively repair critical-sized bone defects. This strategy provides a promising method for the reconstruction of large segmental bone defects.

3D-printed bioactive scaffolds: an emerging strategy for the regeneration of infectious bone defects

3D-printed bioactive scaffolds: an emerging strategy for the regeneration of infectious bone defects