Tissue engineering and regenerative medicine最新文献

Background: Recently, magnetic composite biomaterials have raised attention in bone tissue engineering as the application of dynamic magnetic fields proved to modulate the proliferation and differentiation of several cell types.

Methods: This study presents a novel method to fabricate biofunctional magnetic scaffolds by the deposition of superparamagnetic iron oxide nanoparticles (SPIONs) through thermal Drop-On-Demand inkjet printing on three-dimensional (3D) printed scaffolds. Firstly, 3D scaffolds based on thermoplastic polymeric composed by poly-L-lactic acid/poly-caprolactone/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) were fabricated by Fused Deposition Modelling. Then, in a second step, SPIONs were incorporated onto the surface of the scaffolds by inkjet printing following a designed 2D pattern.

Results: A complete characterization of the resulting magnetic scaffolds was carried out attending to the surface SPIONs deposits, demonstrating the accuracy and versatility of the production technique, as well as the stability under physiological conditions and the magnetic properties. Biological evaluation with human bone marrow mesenchymal stems cells demonstrated biocompatibility of the scaffolds and increased osteogenic capability under the application of a magnetic field, due to the activation of mechanotransduction processes.

Conclusion: These results show that the developed 3D magnetic biofunctional scaffolds can be a very promising tool for advanced and personalised bone regeneration treatments.

Background: Liver fibrosis is a reversible but complex pathological condition associated with chronic liver diseases, affecting over 1.5 billion people worldwide. It is characterized by excessive extracellular matrix deposition resulting from sustained liver injury, often advancing to cirrhosis and cancer. As its progression involves various cell types and pathogenic factors, understanding the intricate mechanisms is essential for the development of effective therapies. In this context, extensive efforts have been made to establish three-dimensional (3D) in vitro platforms that mimic the progression of liver fibrosis.

Methods: This review outlines the pathophysiology of liver fibrosis and highlights recent advancements in 3D in vitro liver models, including spheroids, organoids, assembloids, bioprinted constructs, and microfluidic systems. It further assesses their biological relevance, with particular focus on their capacity to reproduce fibrosis-related characteristics.

Results: 3D in vitro liver models offer significant advantages over conventional two-dimensional cultures. Although each model exhibits unique strengths, they collectively recapitulate key fibrotic features, such as extracellular matrix remodeling, hepatic stellate cell activation, and collagen deposition, in a physiologically relevant 3D setting. In particular, multilineage liver organoids and assembloids integrate architectural complexity with scalability, enabling deeper mechanistic insights and supporting therapeutic evaluation with improved translational relevance.

Conclusion: 3D in vitro liver models represent a promising strategy to bridge the gap between in vitro studies and in vivo realities by faithfully replicating liver-specific architecture and microenvironments. With enhanced reproducibility through standardized protocols, these models hold great potential for advancing drug discovery and facilitating the development of personalized therapies for liver fibrosis.

Background: To evaluate the structural, biochemical, and functional performance of decellularized porcine corneal extracellular matrix (dECM) scaffolds for engineering human corneal endothelium.

Methods: Porcine corneas were decellularized using either 0.3% sodium dodecyl sulfate (SDS) or 1.5 M sodium chloride (NaCl), followed by enzymatic nucleic acid digestion. Histological and biochemical analyses were performed to assess decellularization efficiency and extracellular matrix preservation. Human corneal endothelial cells (hCECs) were cultured on SDS-dECM scaffolds to evaluate cytocompatibility, morphology, and functional outcomes. Therapeutic efficacy was further assessed using a rabbit model of corneal endothelial dystrophy (CED).

Results: SDS-treated corneas showed superior nuclear clearance (residual DNA: 123.60 ± 8.92 ng/mg) compared to NaCl (146.15 ± 5.49 ng/mg), with 95.2% retention of sulfated glycosaminoglycans (sGAGs) and moderate collagen loss (40% of native). In contrast, NaCl better preserved collagen (100% of native) but exhibited incomplete decellularization and lower sGAG retention (71.0%). In vitro, hCECs cultured on SDS-dECM exhibited progressive proliferation, with cell viability surpassing that of TCPS by day 14 (389.01 ± 5.68 vs. 359.65 ± 7.92, p < 0.05). Immunofluorescence confirmed polygonal morphology and ZO-1 expression, indicating intact barrier phenotype. Transparency of dECM scaffolds improved with hCEC culture, with light transmittance at 400 nm increasing from 65.82% (acellular) to 90.13% (double-sided culture). In vivo transplantation of hCEC-seeded SDS-dECM resulted in dose-dependent corneal clarity restoration, with the high-dose group achieving transparency and pachymetry comparable to normal corneas (thickness ~ 602 µm, grading score 0.00 ± 0.00) by 16 weeks.

Conclusions: SDS-dECM scaffolds demonstrated excellent biocompatibility and functional support for human corneal endothelial cells, both in vitro and in vivo. These findings support their potential use as bioengineered alternatives to donor corneas for treating endothelial dysfunction.

Background: This study investigated anti-inflammatory effects of exosomes derived from human fetal cartilage progenitor cells (hFCPC-Exo) and their microRNAs (miRNAs) on the osteoarthritis (OA) phenotype in vitro in comparison with exosomes from bone marrow mesenchymal stem cells (MSC-Exo).

Methods: SW982 cells (synoviocytes) or hFCPCs (chondrocytes) were stimulated with 10 ng/mL IL-1β to mimic OA phenotypes. The effects of hFCPC-Exo and MSC-Exo were compared by measuring the expression of inflammatory cytokines and an anti-inflammatory protein. miRNA profiles of hFCPC-Exo and MSC-Exo were analyzed using a 2588 human miRNA dataset, and miRNAs potentially involved in the anti-inflammatory effect of hFCPC-Exo were selected. miRNA mimics and antisense inhibitors were used to investigate the role of selected miRNAs in the IL-1β signaling pathways.

Results: Both hFCPC-Exo and MSC-Exo significantly decreased the expression of inflammatory cytokines (IL-1β, IL-6, and MCP-1), while slightly increased an anti-inflammatory protein (SOCS1) in IL-1β-treated SW982 cells. miRNA sequencing revealed anti-inflammatory miRNAs present in large amounts in both hFCPC-Exo and MSC-Exo. Among them, miR-125b-5p mimic significantly suppressed the expression of inflammatory cytokines induced by IL-1β, while anti-sense inhibitor of miR-125b-5p efficiently blocked anti-inflammatory effects of hFCPC-Exo. Both hFCPC-Exo and miR-125b-5p inhibited IκBα down-regulation and -NF-κB stabilization in IL-1β-treated SW982 cells. Additionally, hFCPC-Exo and miR-125b-5p showed similar effects on IL-1β-treated hFCPCs as an OA model in chondrocytes by down-regulating the expression of IL-1β, MMP13, and ADAMTS-5 and up-regulating the expression of aggrecan (ACAN) and type II collagen (COL2A1).

Conclusion: This study demonstrated that hFCPC-Exo exhibits anti-inflammatory effects on IL-1β-treated synoviocytes and chondrocytes in vitro possibly by down-regulating the IL-1β-TRAF6-NF-κB pathway via anti-inflammatory miRNAs such as miR-125b-5p.

Background: Strontium ranelate (SR) is an effective bone regeneration drug; however, its low bioavailability and strong hydrophilicity cause a strong cytotoxicity, venous thrombosis, and allergic reactions when administered in its free form. This study aims to enhance the SR bioavailability by utilizing nanostructured lipid carriers (NLC) as a drug delivery system (DDS).

Methods: To improve the drug delivery efficiency and sustained release of the NLC, their surfaces were coated with chitosan oligosaccharide (COS), a natural polymer. The synthesis of COS-NLC was confirmed by measuring particle size and zeta potential, while surface morphology was evaluated using atomic force microscopy (AFM). SR loading efficiencies and release profiles were analyzed via reversed-phase high-performance liquid chromatography (RP-HPLC), and cytotoxicity was evaluated in mouse fibroblast L929 cells.

Results: Particle characterization indicated that the COS coating slightly increased the particle size (i.e., from 128.99 ± 2.77 to 131.46 ± 2.13 nm) and zeta potential (i.e., from - 13.94 ± 0.49 to - 6.58 ± 0.32 mV) of the NLC. The COS-NLC exhibited a high SR-loading efficiency of ~ 86.31 ± 3.28%. An in vitro release test demonstrated an improved sustained release tendency of SR from the COS-NLC compared to that from the uncoated NLC. In cytotoxicity assays using L929 cells, the COS coating reduced the cytotoxicity of the formulated DDS, and the SR-COS-NLC exhibited a 1.4-fold higher cell regeneration effect than SR alone.

Conclusion: These findings suggest that the developed COS-NLC serve as an effective and biocompatible DDS platform for the delivery of poorly bioavailable drugs.

Background: Autotaxin (ATX), an ENPP2 enzyme, regulates lipid signaling by converting lysophosphatidylcholine to lysophosphatidic acid (LPA). Dysregulation of the ATX/LPA axis promotes inflammation and disease progression. BMP-22, a lipid ATX inhibitor, effectively reduces LPA production. However, its clinical utility is hampered by limitations in solubility and pharmacokinetics. To overcome these limitations, we developed BMP-22-incorporated lipid nanoparticles (LNP-BMP) to improve utility while maintaining ATX inhibition efficacy.

Methods: LNP-BMP was synthesized by incorporating DOTAP, DOPE, cholesterol, 18:0 PEG₂₀₀₀-PE, and together with BMP-22. The formulation of LNP-BMP was optimized and characterized by testing different molar ratios of BMP-22. The autophagy recovery and anti-inflammatory effects of LNP-BMP via ATX inhibition were evaluated in both macrophage cell line and mouse-derived primary macrophages.

Results: LNP-BMP was shown to retain its functionality as an ATX inhibitor and maintain the physical characteristics upon BMP-22 integration. Synthesized LNP-BMP exerted superior ability to inhibit ATX activity. When applied to M1-induced macrophages, LNP-BMP exhibited substantial anti-inflammatory effects and successfully restored autophagy activity.

Conclusion: The results demonstrate that LNP-BMP effectively inhibits ATX, achieving both anti-inflammatory effects and autophagy restoration, highlighting its potential as a standalone immunotherapeutic agent. Furthermore, the capacity to load therapeutic drugs into this formulation offers promising opportunities for further therapeutic strategies.

Background: Skin wound healing is a complex process requiring coordinated cellular and molecular interactions. Polynucleotides (PN) and hyaluronic acid (HA) have emerged as promising agents in regenerative medicine due to their ability to enhance cellular proliferation, angiogenesis, and extracellular matrix (ECM) remodeling. Combining PN and HA offers potential synergistic effects, accelerating wound repair.

Methods: PN and HA hydrogels were prepared and evaluated for viscosity and gel stability. Their effects on human dermal fibroblasts (HDF) and keratinocytes (HaCaT) were assessed using migration, proliferation assays, and gene expression analyses for vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9), and matrix metalloproteinase-10 (MMP-10). In vivo studies were conducted using a mouse wound model to observe wound closure and tissue regeneration over 14 days.

Results: The PN-HA mixture demonstrated superior mechanical stability compared to individual components. In vitro, PN-HA significantly enhanced HDF and HaCaT migration, proliferation, and upregulated VEGF, MMP-9, and MMP-10 expression. In vivo, PN-HA treatment accelerated wound closure, improved dermal thickness, and enhanced ECM remodeling, as evidenced by histological analyses.

Conclusion: The PN-HA combination synergistically accelerates wound healing by promoting angiogenesis, cellular migration, and ECM remodeling. These findings highlight its potential as an advanced wound dressing for acute and chronic wound management.

Background: Curcumin, a well-known wound healing agent, faces clinical limitations due to its poor water solubility, rapid degradation, and short plasma half-life. To address these challenges, we developed a self-assembling peptide incorporating an antioxidant sequence (YGDEY), which is capable of not only delivering curcumin but also exhibiting additional bioactivity to enhance wound healing.

Methods: An antioxidant nanocarrier was developed via peptide self-assembly. To design an amphiphilic peptide for the nanocarrier assembly, antioxidant peptide sequence (YGDEY) as the hydrophilic segment and the hydrophobic block (WLWL) were incorporated to single peptide molecule. The peptide's self-assembly behavior and curcumin encapsulation were initially analyzed. Subsequent evaluations included cytocompatibility, cellular uptake, and antioxidant activity.

Results: Driven by strong interactions among their hydrophobic blocks (WLWL), the peptides formed well-defined nanostructures exhibiting high thermal stability. Furthermore, the encapsulation of curcumin within the micelle significantly improved its cellular penetration efficiency. When applied to fibroblast cells, the peptide-curcumin nanocomplexes exhibited synergistically enhanced antioxidant activity, which notably outperformed free curcumin and free peptide in scavenging reactive oxygen species.

Conclusion: These findings highlight the potential of the designed peptide-based nanocarrier to overcome intrinsic limitations of curcumin and enhance its therapeutic efficacy, providing a promising strategy for advanced wound healing applications.

Background: Vascular diseases, including atherosclerosis and thrombosis, are leading causes of morbidity and mortality worldwide, often resulting in vessel stenosis that impairs blood flow and leads to severe clinical outcomes. Traditional mechanical interventions, such as balloon angioplasty and bare-metal stents, provided initial solutions but were limited by restenosis and thrombosis. The advent of drug-eluting stents improved short-term outcomes by inhibiting vascular smooth muscle cell proliferation, however, they faced challenges including delayed reendothelialization and late-stage thrombosis.

Methods: This review highlights the progression from mechanical to biological interventions in treating vascular stenosis and underscores the need for integrated approaches that combine mechanical precision with regenerative therapies.

Results: To address long-term complications, bioresorbable stents were developed to provide temporary scaffolding that gradually dissolves, yet they still encounter challenges with mechanical integrity and optimal degradation rates. Consequently, emerging therapies now focus on biological approaches, such as gene therapy, extracellular vesicle treatments, and cell therapies, that aim to promote vascular repair at the cellular level. These strategies offer the potential for true vascular regeneration by enhancing endothelialization, modulating immune responses, and stimulating angiogenesis.

Conclusion: Integrating mechanical precision with regenerative biological therapies offers a promising future for treating vascular stenosis. A comprehensive approach combining these modalities could achieve sustainable vascular health.

Background: Branched polymers, including star, dendrimers, comb, and biomimetic polymers, are increasingly recognized for their potential in tissue engineering. Their unique architectures and functional properties contribute to enhanced mechanical strength, bioactivity, and adaptability of scaffolds and hydrogels.

Objective: This review explores the diverse applications of branched polymers in tissue engineering and regenerative medicine, emphasizing their role in mimicking the extracellular matrix (ECM) and modulating interactions at the material-bio interface. The structural features of branched polymers, including branching density and functional group distribution, are highlighted for their influence on drug delivery, mechanical properties, and cellular interactions.

Results: Branched polymers offer distinct advantages in tissue engineering: Star polymers: Provide tunable elasticity and facilitate long-range mechanical networking. Dendrimers: Enable precise functionalization for targeted drug delivery and cell signaling. Comb polymers: Enhance porosity and nutrient exchange in scaffolds. Biomimetic polymers: Mimic natural biological systems, promoting cellular adhesion, proliferation, and differentiation.

Conclusion: Branched polymers represent a versatile and promising platform for tissue engineering and regenerative medicine. Their ability to modulate biological interactions and adapt to diverse functional requirements underscores their potential to advance the field.