Biomedical Materials

This study aimed to investigate the osteogenic function of polyetheretherketone (PEEK) scaffolds modified with bone morphogenetic protein 2 (BMP2) and its possibility for orbital fracture repair. The 3D-printed PEEK sheets were combined with BMP2-loaded hyaluronic acid hydrogel (HAH) to fabricate PEEK-BMP2-HAH composite scaffolds. Bone marrow mesenchymal stem cells (BMSCs) were seeded onto PEEK or PEEK-BMP2-HAH scaffolds. Cell adhesion and cell proliferation were measured by transmission electron microscopy and CCK-8 assay. Alkaline phosphatase (ALP) chromogenic, alizarine red S staining, and PCR analysis of Runt-related transcription factor 2 (Runx2), collagen-I (Col-I), Osterix, and osteopontin (OPN) were performed to assess osteogenic activity. The rat orbital fracture defect model is proposed for evaluating the biocompatibility, osteogenic integration, and functional recovery of PEEK orbital implants. Compared with PEEK, cell adhesion and cell proliferation were increased in PEEK-BMP2-HAH scaffolds. ALP activity and mineralized nodule formation were increased in PEEK-BMP2-HAH scaffolds than that in PEEK the mRNA expression of Runx2, Osterix, Col-I and OPN was increased on PEEK-BMP2-HAH scaffolds than that on PEEK at 14 d of osteogenic induction. Besides, a bone defect animal model revealed that BMP2-HAH-modified PEEK scaffolds could effectively facilitate the repair of the orbital bone defect, with increased expression of OPN and Runx2. BMP2-loaded HAH effectively increased adhesion, proliferation, and osteogenic differentiation of BMSCs on PEEK. PEEK-BMP2-HAH scaffolds are expected to become new materials for orbital fracture repair.

Intervention without implantation has become a requirement for developing percutaneous coronary intervention for coronary heart disease. In this paper, the recent advances of three representative types of bioresorbable metal coronary drug-eluting stents (DESs) are reviewed, and the material composition, structural design, mechanical properties and degradability of iron-based, magnesium-based and zinc-based bioresorbable metal coronary DES are analyzed. The methods of regulating the radial strength and degradation rate of the coronary stents are summarized, and the in vivo/in vitro performance evaluation methods and ideal testing systems of the bioresorbable metal coronary DES are analyzed. Advances made in bioresorbable metal coronary DES, the existing shortcomings and optimization methods are proposed, and the future development direction is prospected.

Nanozymes based on metals have been regarded as a promising candidate in the metabolic reprogramming of low-survival, refractory glioblastoma multiforme (GBM). However, due to size limitations, nanozymes struggle to balance catalytic activity with the ability to cross the blood-brain barrier (BBB), limiting their efficiency in GBM therapy. Herein, we establish a hybrid nanocluster, AuMn NCs, by cross-linking ultrasmall nano-gold (Au) and manganese oxide (MnO₂), which overcomes the size requirement conflict for integrating catalytic activities, long-period circulation, photothermal effect, glucose consumption, and chemodynamic effect for multimodality treatment against GBM. After administered intravenously, the overall large-size AuMn NCs can escape kidney filtration and cross the BBB for GBM accumulation. Then the individual ultrasmall nano-MnO₂ components effectively catalyze H₂O₂ degradation as catalase to produce oxygen, which is utilized by individual ultrasmall nano-Au components to consume glucose as glucose oxidase for starvation therapy. The H₂O₂ generated during Au-catalyzed glucose consumption further facilitates MnO₂ catalytic activity. Such positive feedback overwhelmingly intervenes in the glucose metabolism of GBM. Concurrently, clustered Au-induced photothermal effect and released Mn²⁺-induced chemodynamic effect further contribute to eliminating GBM cells. The versatile clustered nanozyme offers a feasible strategy for the multimodality intervention of GBM.

Titanium alloy dental implants play a crucial role in the field of oral rehabilitation. However, the use of solid designs can give rise to mechanical problems such as mismatched compressive elastic modulus with the host bone tissue, resulting in stress shielding and stress concentration. These problems have been a persistent bottleneck in their application effectiveness. To overcome this challenge, this study creatively designed five types of porous structures with cylindrical thin wall based on the Gibson–Ashby theoretical model. The aim is to optimize the mechanical performance of dental implants, enhance their compatibility with the host bone tissue, and utilize selective laser melting technology for precise fabrication of porous structures using Ti6Al4V material. Through a combination of simulation analysis and compression experiments, the stress and strain distributions of the five structures are systematically investigated under different bite conditions. The experimental results demonstrate that all five porous structures designed in this study effectively alleviate stress shielding phenomenon in dental implants, significantly improving the bonding performance between the implants and bone tissue. This meets the clinical implantation requirements and provides strong theoretical support for the application of dental implants in clinical settings.

In 3D bioprinting, two promising approaches have gained significant attention: the use of support materials during printing and the utilization of bioinks gelled through ruthenium(II) tris-bipyridyl dication ([Ru(bpy)₃]²⁺)-catalyzed photocrosslinking consuming sodium persulfate (SPS). Integrating these approaches while ensuring simplicity and printability remains a challenge. To address this challenge, we propose a technique in which the support material containing SPS is alternately extruded with the bioink containing polymer having phenolic hydroxyl moieties (polymer-Ph) and [Ru(bpy)₃]²⁺ under visible light irradiation. This method eliminates the problems of light shading and deformation caused by the support material, as the contact between the alternately extruded ink and the support material initiates the gelation of the ink via photocrosslinking. Using an ink containing 0.5 w/v% hyaluronic acid with phenolic hydroxyl moieties (HA-Ph) and 2.0 mM [Ru(bpy)₃]²⁺ alongside a support material containing 10 mM SPS, various constructs were successfully printed under 450 nm visible light. The human hepatoblastoma cells embedded in the printed construct showed approximately 95% viability after printing and proliferation over 14 d of culture. These results highlight the potential of this method to advance 3D bioprinting for tissue engineering applications.

Intervention without implantation has become a requirement for developing percutaneous coronary intervention for coronary heart disease. In this paper, the recent advances of three representative types of bioresorbable metal coronary drug-eluting stents (DESs) are reviewed, and the material composition, structural design, mechanical properties and degradability of iron-based, magnesium-based and zinc-based bioresorbable metal coronary DES are analyzed. The methods of regulating the radial strength and degradation rate of the coronary stents are summarized, and the in vivo/in vitro performance evaluation methods and ideal testing systems of the bioresorbable metal coronary DES are analyzed. Advances made in bioresorbable metal coronary DES, the existing shortcomings and optimization methods are proposed, and the future development direction is prospected.

Temporary anchorage devices (TADs) have evolved as useful anchorage providers for orthodontic tooth movements. To improve the stability of TADs, a number of modifications on their surface have been developed and investigated. This review comprehensively summarizes recent findings of clinically applied surface modifications of TADs and compared the biological improvement of these modifications. We focused on sandblasting, large-grit, acid etching (SLA), anodic oxidation (AO) and ultraviolet photofunctionalization (UVP). In vitro, in vivo and clinical studies of these surface modifications on TADs with clear explanations, low possibility of bias and published in English were included. Studies demonstrated that SLA, AO and UVP enhance cell attachment, proliferation, and differentiation in vitro. The biocompatibility and osteoconductivity of TAD surface are improved in vivo. However, in clinical studies, the changes are generally not so impressive. Furthermore, this review highlights the promising potential in combinations of different modifications. In addition, some other surface modifications, for instance, the biomimetic calcium phosphate coating, deserve to be proposed as future strategies.

Bioprinting, an advanced additive manufacturing technology, enables the fabrication of complex, viable three-dimensional (3D) tissues using bioinks composed of biomaterials and cells. This technology has transformative applications in regenerative medicine, drug screening, disease modeling, and biohybrid robotics. In particular, in situ bioprinting has emerged as a promising approach for directly repairing damaged tissues or organs at the defect site. Unlike traditional 3D bioprinting, which is confined to flat surfaces and require complex equipment, in situ techniques accommodate irregular geometries, dynamic environments and simple apparatus, offering greater versatility for clinical applications. In situ bioprinting via hand-held devices prioritize flexibility, portability, and real-time adaptability while allowing clinicians to directly deposit bioinks in anatomically complex areas, making them cost-effective, accessible, and suitable for diverse environments, including field surgeries. This review explores the principles, advancements, and comparative advantages of robotic and hand-held in situ bioprinting, emphasizing their clinical relevance. While robotic systems excel in precision and scalability, hand-held bioprinters offer unparalleled flexibility, affordability, and ease of use, making them a valuable tool for personalized and minimally invasive tissue engineering. Future research should focus on improving biosafety, aseptic properties, and bioink formulations to optimize these technologies for widespread clinical adoption.

Natural polymer-based hydrogels, generally composed of hydrophilic polymers capable of absorbing large amounts of water, have garnered attention for biomedical applications because of their biocompatibility, biodegradability, and eco-friendliness. Natural polymer-based hydrogels derived from alginate, starch, cellulose, and chitosan are particularly valuable in fields such as drug delivery, wound dressing, and tissue engineering. However, compared with synthetic hydrogels, their poor mechanical properties limit their use in load-bearing applications. This review explores recent advancements in the enhancement of the mechanical strength of natural hydrogels while maintaining their biocompatibility for biomedical applications. Strategies such as chemical modification, blending with stronger materials, and optimized cross-linking are discussed. By improving their mechanical resilience, natural hydrogels can become more suitable for demanding biomedical applications, like tissue scaffolding and cartilage repair. Additionally, this review identifies the ongoing challenges and future directions for maximizing the potential of natural polymer-based hydrogels in advanced medical therapies.

Bone defects, resulting from trauma, tumor removal, infection, or congenital anomalies, are increasingly prevalent in clinical practice. Progress in bone tissue engineering has significantly advanced bone regeneration techniques. Chitosan-based nanoparticles (ChNPs) have emerged as a promising drug delivery system due to their inherent ability to enhance bone regeneration. These nanoparticles can extend the activity of osteogenic factors while ensuring their controlled release. Common synthesis methods for ChNPs include ionic gelation, complex coacervation, and polyelectrolyte complexation. ChNPs have demonstrated effectiveness in bone regeneration by delivering osteogenic agents, including DNA/RNA, proteins, and therapeutics. This review provides a comprehensive analysis of recent studies on ChNPs in bone regeneration, sourced from the PubMed database. It examines their synthesis techniques, advantages as drug delivery systems, incorporation into scaffold materials, and the challenges that remain in the field.

Bone injury presents a prevalent challenge in clinical settings, with traditional treatment modalities exhibiting inherent limitations. Recent advancements have highlighted the potential of combining physical exercise intervention and innovative materials to enhance bone repair and recovery. This review explores the synergistic effects of physical exercise and novel materials in promoting bone regeneration, with a particular focus on the role of neurovascular coupling mechanisms. Physical exercise not only stimulates bone cell function and blood circulation but also enhances the bioactivity of novel materials, such as nanofiber membranes and smart materials, which provide supportive scaffolds for bone cell attachment, proliferation, and differentiation. Neurovascular coupling, involving the interaction between neural activity and blood flow, is integral to the bone repair process, ensuring the supply of nutrients and oxygen to the injured site. Studies demonstrate that the combination of physical exercise and novel materials can accelerate bone tissue regeneration, with exercise potentially enhancing the bioactivity of materials and materials improving the effectiveness of exercise. However, challenges remain in clinical applications, including patient variability, material biocompatibility, and long-term stability. Optimizing the integration of physical exercise and novel materials for optimal therapeutic outcomes is a key focus for future research. This review examines the collaborative mechanisms between physical exercise, novel materials, and neurovascular coupling, emphasizing their potential and the ongoing challenges in clinical settings. Further exploration is needed to refine their application and improve bone repair strategies.

Compared with traditional soft tissue wound closure methods such as sutures and staplers, bioadhesives have significant advantages in terms of tissue compatibility, ease of use, and wound adaptability, making them a hot topic among current wound repair materials. This study aimed to select polyurethane materials with good biocompatibility and high mechanical strength, optimize the prepolymer formula, develop new curing agents, and obtain a new dual-component polyurethane bioadhesive. Furthermore, key research will be conducted on its mechanical properties and tissue adhesion performance. The results show that through the optimization of prepolymer formulations and the development of novel curing agents, a dual-component polyurethane bioadhesive with good biocompatibility, flexibility, and high adhesive strength was obtained. This adhesive can quickly and effectively bond common soft tissue (skin, muscle) traumatic wounds, with an adhesive strength of up to 72 kPa. This adhesive matches well with the mechanical properties of soft tissues and safely and tightly adheres to the surface of soft tissues. Additionally, this dual-component polyurethane adhesive holds promise for repairing other soft tissues, such as the lungs and intestines, with broad application prospects.

Although human periodontal ligament stem cell (hPDLSC)-based tissue engineering have been promising for regenerating periodontal bone tissue, their effectiveness is limited by the lack of an optimal delivery vehicle for these cells. Therefore, this study reports a gelatin methacryloyl (GelMA) microsphere system, incorporating injectable platelet-rich fibrin (i-PRF) and nano-hydroxyapatite (nHA) as carriers for hPDLSCs. These hybrid microspheres were effectively produced using droplet microfluidics technology, achieving a size range of 100–300 μm. Importantly, the release profile of multiple growth factors (GFs) from the microspheres was significantly extended, lasting up to 28 days. Moreover, the released GFs and nHA considerably enhanced the proliferation of encapsulated hPDLSCs along with their spreading and osteogenic differentiation. The microspheres facilitated the development of Spheroid-like cell aggregates within two weeks of culture, demonstrating a promising approach for advanced periodontal bone tissue regeneration.

Anterior foregut endoderm (AFE) derived from induced pluripotent stem cells (iPSCs) is an important cell source in stem cell technology by giving rise to some important linages like lung progenitors and thyroid cells. Coating substrates play a critical role in AFE generation. Currently, conventional large molecule proteins like Matrigel are used in most differentiation protocols. However, the complex components and mechanisms of these coatings have limited both exploration of cell-ECM interaction and potential clinical applications. In this study, we identified eight pure synthetic integrin-binding short peptides as effective coatings for iPSC growth and AFE generation with an integrin-binding peptide array. Our results showed that integrin α5β1, αVβ8 and αIIbβ3-binding peptides supported adhesion, expansion of iPSCs and AFE generation in guided differentiation via definitive endoderm in full-anchorage-dependent manner, and AFE generation was also found on coatings based on integrin α3β1, α6β1, αVβ1, αVβ6, αMβ2-binding peptides following a process with temporal suspension growth in DE inducing stage, with lower AFE generation efficiency compared with full-anchorage-dependent peptide groups and Matrigel. According to the results, integrin α5β1-binding peptide is the most promising defined substrate for AFE inducing because of the equivalent efficiency with traditional Matrigel coating on supporting iPSC expansion and differentiation towards AFE. Additionally, the other seven peptide-based coatings also exhibit potential and could be further investigated for developing synthetic coating strategies in future studies involving AFE. Our findings provide valuable insights into the role of integrin and ECM function and hold great potential for disease modeling as well as therapeutic exploration of AFE origin organs.

The erosion and drug release behavior of an injectable hydrogel composed of ethoxylated trimethylolpropane tri-3-mercaptopropionate (ETTMP) and poly(ethylene glycol) diacrylate (PEGDA) were determined under physiological conditions. The water and polymer mass changes were monitored over time to characterize the swelling/deswelling and erosion of the hydrogel tablets. Experimental data were collected for hydrogels with varying polymer fractions. These data were used to develop an empirical model for predicting the eroding mass change and equilibrium water content across different compositions. Three easily detectable model drugs (methylene blue, sulforhodamine 101, and chloroquine) were loaded into 25, 35, and 50 wt% polymer hydrogels to understand their drug release behavior. The gelation time and time for total release was dependent on the weight fraction of the polymer in the hydrogel and varied with the pH of the drug solutions, with more acidic drugs increasing gelation time. Complete drug release was not observed for methylene blue due to the reaction with ETTMP thiol groups, demonstrating the importance of understanding the potential interactions between the drug and polymer. Drug-loaded hydrogels were also monitored for erosion and were found to swell more than their neat counterparts for all drugs tested, suggesting an effect of drug loading on the extent of hydrogel crosslinking.

Osteoporosis poses a significant public health challenge, necessitating advanced bone regeneration solutions. While gelatin methacrylate (GelMA) hydrogels show promise, conventional fabrication methods using aqueous two-phase systems (ATPS) often result in inconsistent mechanical properties and structural irregularities. This study presents an approach synthesizing new methods and parameters for bR-GelMA, utilizing stop-flow lithography (SFL) to fabricate highly elastic micro-particles incorporating bioactive glass particles. SFL, in contrast to ATPS, offers precise control over micro-particle formation, enabling the production of uniform and stable structures ideal for biomedical applications. The resulting elastic micro-particles demonstrate rapid degradation, enhanced cell proliferation, and improved mechanical strength without compromising flexibility. This innovative approach using SFL to fabricate GelMA-based micro-particles holds significant promise for bone regeneration and other critical therapeutic applications.

The erosion and drug release behavior of an injectable hydrogel composed of ethoxylated trimethylolpropane tri-3-mercaptopropionate (ETTMP) and poly(ethylene glycol) diacrylate (PEGDA) were determined under physiological conditions. The water and polymer mass changes were monitored over time to characterize the swelling/deswelling and erosion of the hydrogel tablets. Experimental data were collected for hydrogels with varying polymer fractions. These data were used to develop an empirical model for predicting the eroding mass change and equilibrium water content across different compositions. Three easily detectable model drugs (methylene blue, sulforhodamine 101, and chloroquine) were loaded into 25, 35, and 50 wt% polymer hydrogels to understand their drug release behavior. The gelation time and time for total release was dependent on the weight fraction of the polymer in the hydrogel and varied with the pH of the drug solutions, with more acidic drugs increasing gelation time. Complete drug release was not observed for methylene blue due to the reaction with ETTMP thiol groups, demonstrating the importance of understanding the potential interactions between the drug and polymer. Drug-loaded hydrogels were also monitored for erosion and were found to swell more than their neat counterparts for all drugs tested, suggesting an effect of drug loading on the extent of hydrogel crosslinking.

The development of magnesium-based intraocular drug delivery devices holds significant promise for biomedical applications, particularly in treating wet age-related macular degeneration (AMD) using vascular endothelial growth factor (VEGF) inhibitors such as bevacizumab. Magnesium's rapid degradation, which can be finely tuned to achieve the controlled release required for AMD treatment, along with its well-established biocompatibility and biodegradable properties, positioning it as an ideal material for these applications. The study aimed to evaluate magnesium's potential as a carrier for ocular drug delivery systems by demontrating the stability of monoclonal antibodies, specifically bevacizumab, in the presence of magnesium corrosion products and the biocompatibility of these products with various cell lines, including murine fibroblasts (3T3), rat retinal Müller cells (RMC-1), and human retinal pigment epithelial cells (ARPE19). The stability of bevacizumab with pure magnesium (Mg) was investigated through an indirect ELISA protocol, developed and customized for this specific aim. The biocompatibility of Mg corrosion products was assessed by toxicological evaluations through MTT and Trypan Blue Viability assays, along with cell cycle analysis. Results demonstrated no significant impact of Mg corrosion products on bevacizumab stability, with changes in mean values consistently below or equal to 10%. Furthermore, Mg extracts showed minimal cytotoxicity, as metabolic activity exceeded 80% across all cell lines, classified as Grade 0/1 cytotoxicity under ISO 10993–5 standards. Cell viability, proliferation, and morphology remained unaffected for up to 72 hours of exposure. This study provides the first in vitro evaluation of bevacizumab's stability in the presence of magnesium corrosion products and its biocompatibility with retinal cell lines, laying the foundation for future ophthalmic research and underscoring magnesium's potential as a material for intraocular drug delivery systems.

Temporary anchorage devices (TADs) have evolved as useful anchorage providers for orthodontic tooth movements. To improve the stability of TADs, a number of modifications on their surface have been developed and investigated. This review comprehensively summarizes recent findings of clinically applied surface modifications of TADs and compared the biological improvement of these modifications. We focused on sandblasting, large-grit, acid etching (SLA), anodic oxidation (AO) and ultraviolet photofunctionalization (UVP). In vitro, in vivo and clinical studies of these surface modifications on TADs with clear explanations, low possibility of bias and published in English were included. Studies demonstrated that SLA, AO and UVP enhance cell attachment, proliferation, and differentiation in vitro. The biocompatibility and osteoconductivity of TAD surface are improved in vivo. However, in clinical studies, the changes are generally not so impressive. Furthermore, this review highlights the promising potential in combinations of different modifications. In addition, some other surface modifications, for instance, the biomimetic calcium phosphate coating, deserve to be proposed as future strategies.

Bioprinting, an advanced additive manufacturing technology, enables the fabrication of complex, viable three-dimensional (3D) tissues using bioinks composed of biomaterials and cells. This technology has transformative applications in regenerative medicine, drug screening, disease modeling, and biohybrid robotics. In particular, in situ bioprinting has emerged as a promising approach for directly repairing damaged tissues or organs at the defect site. Unlike traditional 3D bioprinting, which is confined to flat surfaces and require complex equipment, in situ techniques accommodate irregular geometries, dynamic environments and simple apparatus, offering greater versatility for clinical applications. In situ bioprinting via hand-held devices prioritize flexibility, portability, and real-time adaptability while allowing clinicians to directly deposit bioinks in anatomically complex areas, making them cost-effective, accessible, and suitable for diverse environments, including field surgeries. This review explores the principles, advancements, and comparative advantages of robotic and hand-held in situ bioprinting, emphasizing their clinical relevance. While robotic systems excel in precision and scalability, hand-held bioprinters offer unparalleled flexibility, affordability, and ease of use, making them a valuable tool for personalized and minimally invasive tissue engineering. Future research should focus on improving biosafety, aseptic properties, and bioink formulations to optimize these technologies for widespread clinical adoption.

Curcumin is a natural polyphenol extracted from plants that interacts with various molecular targets and exhibits antioxidant, antibacterial, anticancer, and anti-aging properties. Due to its various pharmacological activities and high safety margin, curcumin has been used in the prevention and treatment of various diseases, including Alzheimer's, heart, and rheumatic immune diseases. To develop curcumin eye drops that can be used as antioxidant and antibacterial agents after phacoemulsification, we designed a nano-based drug delivery system to improve curcumin bioavailability and duration of action. We successfully prepared a zeolitic imidazolate framework-8 (ZIF-8) coated with chitosan-liposome for curcumin delivery (Cur@ZIF-8/CS-Lip). This system enables sustained curcumin release for over 20 h in vitro and exhibits excellent biosafety, antioxidant, and antibacterial activities. Therefore, we proposed that Cur@ZIF-8/CS-Lip may reduce the incidence of oxidative stress and infections following cataract surgery.

NanoMIPs are nanoscale molecularly imprinted polymers (MIPs) ranging in size between 30 to 300 nm offering a high affinity binding reagent as an alternative to antibodies. They are being extensively researched for applications in biological extraction, disease diagnostics and biosensors. Various methodologies for nanoMIP production have been reported demonstrating variable timescales required, sustainability, ease of synthesis and final yields. We report herein a fast (<2 h) method for one pot aqueous phase synthesis of nanoMIPs using an acrylamide-based monomer and N,N'-methylenebisacrylamide crosslinker. NanoMIPs were produced for a model protein template namely haemoglobin from bovine species. We demonstrate that nanoMIPs can be produced within 15 min. We investigated reaction quenching times between 5 and 20 min. Dynamic light scattering results demonstrate a distribution of particle sizes (30–900 nm) depending on reaction termination time, with hydrodynamic particle diameter increasing with increasing reaction time. We attribute this to not only particle growth due to polymer chain growth but based on AFM analysis, also a tendency (after reaction termination) for particles to agglomerate at longer reaction times. Batches of nanoMIPs ranging 400–800 nm, 200–400 nm and 100–200 nm were isolated using membrane filtration. The batches were captured serially on decreasing pore size microporous polycarbonate membranes (800–100 nm) and then released with sonication to isolate nanoMIP batches in the aforementioned ranges. Rebinding affinities of each batch were determined using electrochemical impedance spectroscopy, by first trapping nanoMIP particles within an electropolymerized thin layer. Binding constants determined for NanoMIPs using the E-MIP sensor approach are in good agreement with surface plasmon resonance results. We offer a rapid (<2 h) and scalable method for the mass production (40–80 mg per batch) of high affinity nanoMIPs.

This study aims to employ poly-L-lactic acid (PLLA) and poly(p-dioxanone) (PPDO), loaded with naringin (NAR) to fabricate a functionalized degradable mesh which can promote abdominal wall hernia (AWH) repair. Three meshes named PPDO, PLLA/PPDO, and PLLA/PPDO/NAR were fabricated by electrospinning. The physical and chemical properties of the meshes were evaluated from the aspects of morphology, wettability, chemical composition, mechanical properties, and in vitro degradation. Then, the meshes were implanted into rats to evaluate their repair effects on abdominal wall defect models. The mechanical properties of PLLA/PPDO/NAR mesh were superior to the other two meshes, with a fixed tensile strength of 36.47 ± 2.40 N cm⁻¹ and an elongation at break of 287.98% ± 51.67%, which adequately met the mechanical strength required for the human abdominal wall. The core–shell structure effectively delayed the degradation of PLLA/PPDO as well as PLLA/PPDO/NAR mesh, and drug release of PLLA/PPDO/NAR mesh. On the 7th, 14th, and 28th day after implantation, more neovascularization and tissue formation were observed in the PLLA/PPDO/NAR group and the newborn collagen was arranged in a regular and neat manner compared to the other two groups. The immunohistochemical results showed that the PLLA/PPDO/NAR mesh promoted abdominal wall repair by inhibiting the expression of matrix metalloproteinase2 as well as interleukin-6, and increasing the expression of vascular endothelial growth factor. The PLLA/PPDO/NAR mesh is promising for application in AWH repair.

Rapid and strategic cell placement is necessary for high throughput tissue fabrication. Current adhesive cell patterning systems rely on fluidic shear flow to remove cells outside of the patterned regions, but limitations in washing complexity and uniformity prevent adhesive patterns from being widely applied. Centrifugation is commonly used to study the adhesive strength of cells to various substrates; however, the approach has not been applied to selective cell adhesion systems to create highly organized cell patterns. This study shows centrifugation as a promising method to wash cellular patterns after selective binding of cells to the surface has taken place. After patterning H9C2 cells using biotin-streptavidin as a model adhesive patterning system and washing with centrifugation, there is a significant number of cells removed outside of the patterned areas of the substrate compared to the initial seeding, while there is not a significant number removed from the desired patterned areas. This method is effective in patterning multiple size and linear structures from line widths of 50–200 μm without compromising immediate cell viability below 80%. We also test this procedure on a variety of tube-forming cell lines (MPCs, HUVECs) on various tissue-like surface materials (collagen 1 and Matrigel) with no significant differences in their respective tube formation metrics when the cells were seeded directly on their unconjugated surface versus patterned and washed through centrifugation. This result demonstrates that our patterning and centrifugation system can be adapted to a variety of cell types and substrates to create patterns tailored to many biological applications.

The reconstruction of large-sized soft tissue defects remains a substantial clinical challenge, with adipose tissue engineering emerging as a promising solution. The acellular dermal matrix (ADM), known for its intricate spatial arrangement and active cytokine involvement, is widely employed as a scaffold in soft tissue engineering. Since ADM shares high similarity with decellularized adipose matrix, it holds potential as a substitute for adipose tissue. This study explores the adipogenic ability of a spongy material derived from ADM via vacuum-thermal crosslinking (T-ADM), characterized by high porosity, adjustable thickness, and suitable mechanical strength. Adipose-derived stem cells (ADSCs) are considered ideal seed cells in adipose tissue engineering. Nevertheless, whether pre-adipogenic induction is necessary before their incorporation remains debatable. In this context, ADSCs, both with and without pre-adipogenic induction, were seeded into T-ADM to regenerate vascularized adipose tissue. A comparative analysis of the two constructs was performed to evaluate angiogenesis and adipogenesis in vitro, and tissue regeneration efficacy in vivo. Additionally, RNA-seq analysis was utilized to investigate the potential mechanisms. The results showed that T-ADM exhibited good performance in terms of volume retention and maintenance of adipocyte phenotype, confirming its suitability as a scaffold for adipose tissue engineering. In-vitro outcomes demonstrated that pre-adipogenic induction enhanced the adipogenic level of ADSCs, but reduced their ability to promote vascularization. Furthermore, constructs utilizing pre-induced ADSCs showed an insignificant superiority in in-vivo fat formation, and neovascularization compared with those with non-induced ADSCs, which may be attributed to similar macrophage regulation, and balanced modulation of the proliferator-activated receptor-γ and hypoxia-inducible factor 1 α pathways. Consequently, the direct use of ADSCs is advocated to streamline the engineering process and reduce associated costs. The combined strategy of T-ADM with ADSCs proves to be feasible, convenient and effective, offering substantial potential for addressing large-sized tissue deficits and facilitating clinical applications.