Regenerative Biomaterials最新文献

Androgenic alopecia (AGA), the most common form of progressive hair loss in both males and females, significantly impacts patients' quality of life and confidence. Current therapies, such as minoxidil, are limited by poor patient compliance and low transdermal bioavailability, highlighting the need for more effective treatments. In this study, we identified collagen XVII (COL17) as a key player in AGA-like model pathogenesis, observing its significant downregulation in a testosterone-induced AGA-like mouse model. This reduction was accompanied by abnormal hair follicle morphology, decreased proliferation and impaired angiogenesis. To address this, we developed recombinant human COL17 fragment (800-1300 aa) (rhCOL17p) expressed and purified from E. coli, which demonstrated dose-dependent enhancement of dermal papilla cell adhesion, migration and proliferation in vitro. To overcome transdermal delivery challenges, we designed a dissolving microneedle (MN) patch using hyaluronic acid as a matrix. The rhCOL17p-MN achieved 96% skin penetration and sustained release of 96% within 28 h in vitro, with residual fluorescence detectable in mouse skin for up to 6 days. In vivo, the 4-mg/ml rhCOL17p-MN achieved a mean hair coverage of ∼97% by Day 14, which was statistically equivalent to the efficacy of 5% minoxidil, with increased follicle density, anagen-phase transition and CD31⁺ vascularization. Histological analysis revealed restored follicle structure and upregulated β-catenin⁺ and SRY-box gene 9 (SOX9⁺), indicating activation of stem cell and proliferative signaling pathways. The rhCOL17p-MN also demonstrated low hemolysis (<0.5%) and robust mechanical stability (≥0.2 N/needle), confirming its safety and feasibility. These findings establish COL17 downregulation as a critical mechanism in AGA and demonstrate that MN-delivered rhCOL17p promotes hair regeneration through multi-pathway regulation, offers preclinical evidence supporting its potential as a candidate strategy for further investigation in AGA-related research.

Craniosynostosis (CS), characterized by the premature fusion of cranial sutures, often results from aberrant activation of Fibroblast growth factor receptor 2 (FGFR2), a major regulator of osteogenic differentiation in cranial mesenchyme. Despite surgical interventions, recurrence and complications remain common, underscoring the need for targeted molecular therapies. In this study, we developed a novel formulation of bioactive nanocomposite hydrogel-based ink designed for localized, sustained delivery of therapeutic small interfering RNAs (siRNAs) targeting FGFR2. The delivery system combines gelatin methacryloyl (GelMA), a biocompatible and photo-crosslinkable hydrogel, with poly-lactic-co-glycolic acid (PLGA) nanoparticles (NPs), creating an injectable and mouldable platform with potential for future craniofacial application. Selected siRNAs achieved up to 90% FGFR2 mRNA knockdown and reduced downstream protein signalling activation, including pFGFR2 (60%), pERK1/2 (37%) and RUNX2 (43%) in patient-derived cells. PLGA NPs demonstrated high siRNA encapsulation efficiency, efficient cytoplasmic delivery and lysosomal escape. When embedded in GelMA and 3D-printed, the GelMA-NP system showed sustained NP retention and a controlled-release profile, maintaining functional gene silencing for up to 20 days. This multifunctional platform not only supports FGFR2 modulation in CS but also holds translational promise as a customizable scaffold for delivering other bioactive compounds, advancing paediatric cranioplasty outcomes.

Artificial energy supply modules that can produce adenosine triphosphate (ATP) through natural or synthetic structures are crucial for supporting artificial cells with therapeutic purposes. However, their advanced biomedical application is hindered by poor stability, short lifespan and low output efficiency. In this study, an artificial light-controlled energetic module with long-term activity, termed thylakoid-loaded microgel (TM), is created by encapsulating spinach-derived thylakoid into alginate/gelatin microgels. The TM effectively retains the photosynthetic light reactions of thylakoids, including the electron transfer capacity of photosystem II and ATP production, and releases the produced ATP to external environment. As a proof of concept, the TM successfully drives the luciferin/luciferase reaction both within and outside the microgel compartment. In addition, the encapsulated thylakoids exhibit a significantly prolonged activity, with the high photosystem II activity and ATP production lasting for at least 96 h. The long-term activity is attributed to the oxidation shielding efficacy, protein and pigment degradation inhibition and membrane structural stabilization. This study presents a strategy for developing artificial energy supply modules with efficient energy output and long-term activity, holding great promise in artificial cell construction and biosynthesis.

We previously described the production of hydrophilic hydrogel scaffolds of cross-linked chitosan that closely matched the biomechanical properties of native human tarsus. In the present preclinical study we appraised the spatio-temporal tissue response to the implantation of these chitosan scaffolds into rat eyelids. Acellular hydrogel scaffolds were produced from Good Manufacturing Practice (GMP)-compliant chitosan and implanted into rat eyelids. Tissue was harvested and fixed up to 24 weeks post-surgery for histological examination of the tissue response to both the surgical procedure itself and to the chitosan implantation. Assessment encompassed inflammation, the foreign body reaction (FBR) and infiltration of native cells into the implant region, along with scaffold degradation. Three days after implantation of the chitosan into rat eyelids, neutrophils were observed in the vicinity of the chitosan but their prevalence declined rapidly thereafter. Both pro-inflammatory M1-macrophages and anti-inflammatory M2-macrophages were also observed post-implantation at the scaffold-tissue interface but the former cells declined after 4 weeks. Unlike the M1-macrophages, the M2-macrophages rarely infiltrated the scaffold at any time point. T cells and MHC class II antigen-presenting cells were predominantly increased at the tissue-scaffold interface and, to a minor degree, within the scaffold, in the weeks following surgery. In the weeks following implantation, a fibro-collagenous capsule gradually formed at the margins of the scaffolds, denoting the classic FBR. This was accompanied by the appearance of foreign body giant cells, moderate to substantial degradation and engulfment of chitosan by infiltrating cells, and localized tissue remodelling characterized by proliferation of fibroblasts, deposition of collagenous extracellular matrix (ECM) material and rudimentary formation of vascular elements within the scaffold. Although the chitosan scaffolds initially elicited widespread inflammation and an FBR, longer-term tissue remodelling and scaffold degradation suggested their biocompatibility. These data support that chitosan hydrogel scaffolds could, therefore, serve as suitable tarsal substitute material in situ.

Natural functional regeneration of the tendon-bone interface in rotator cuff repair surgery remains a major challenge and requires the development of innovative therapeutic strategies. Hydrogels with biomechanical adaptability and regenerative microenvironment modulation are promising candidates for treating such injuries. In this study, an ROS-responsive adhesive nanocomposite hydrogel (TPGA@CZB) was developed to enhance tendon-to-bone interface repair by on-demand drug release to modulate the inflammatory microenvironment and promote cell differentiation. The hydrogel consisted of baicalin (Ba)-loaded Cu-Zn bimetallic-organic framework (CZB), N-[tris(hydroxymethyl) methyl] acrylamide (THMA), poly(ethylene glycol) diacrylate (PEGDA) and phenylboronic acid modified methacrylated gelatin (GelMA-CPBA). Owing to its multi-crosslinked structure, TPGA@CZB exhibits excellent adhesive properties (lap shear strength reaching 110.90 ± 15.38 kPa) and mechanical adaptability (compressive strain exceeding 80% and tensile strain of 196.24 ± 3.87%). Additionally, TPGA@CZB demonstrated favorable ROS-responsive release characteristics, with the cumulative release of Ba in H₂O₂ solution (63.90 ± 4.76% at 96 h) being significantly higher than that in PBS solution (48.39 ± 1.56% at 96 h). Furthermore, cellular experiments revealed that TPGA@CZB effectively scavenged intracellular ROS, inhibits the NF-κB signaling pathway, regulates macrophage polarization and promotes osteogenic differentiation and chondrogenesis. In vivo studies confirmed that TPGA@CZB treatment effectively optimized collagen remodeling, enhanced osteogenesis and cartilage formation, as well as modulated the inflammatory microenvironment at the injury site. In conclusion, this nanocomposite hydrogel integrates "mechanical support-controlled drug release-microenvironment regulation" into a single platform, offering a promising multifunctional therapeutic strategy for enhancing tendon-bone interface regeneration.

Skeletal muscle ischemia, resulting from impaired blood flow, is a prevalent clinical issue and a leading cause of amputation. Plant-derived exosome-like nanovesicles (ELNs) have emerged as promising candidates due to their diverse bioactive components with antioxidant, anti-inflammatory and regenerative properties. In this study, exosome-like nanovesicles (RhELNs) extracted from the root of Rhodiola rosea, a traditional Chinese medicine, were proved to have a good ability to promote the regeneration of vascular endothelial cells under hypoxia by EdU experiment and transwell experiment in vitro. After the treatment of mice with RhELNs injected into the tail vein, it was found that the inflammation level of the skeletal muscle of the mice was decreased, the degree of fibrosis was alleviated, the blood flow was restored, skeletal muscle atrophy and limb gangrene were improved. These results indicate that RhELNs can promote the recovery of ischemic skeletal muscle and angiogenesis. Furthermore, we identified a novel microRNA (novel-mirNA-115-5p) in RhELNs, which plays an important role in RhELNs. It protects vascular endothelial cells from mitochondrial damage by targeting TXNIP and it promotes vascular regeneration by reducing cellular pyroptosis under hypoxia conditions through inhibition of the TXNIP- NLRP3 pathway. These results suggest that RhELNs represent a promising new approach for treating lower limb skeletal muscle ischemic diseases.

Periodontitis is a chronic inflammatory disease affecting periodontal supporting tissues. Untreated, it causes irreversible alveolar bone destruction, ultimately leading to tooth loss. Periodontitis-associated pathogenic bacteria/metabolites and pro-inflammatory factors can initiate or exacerbate systemic disease through the circulation. Endothelial cells, forming the interface between circulation and tissues, play a key role in disease progression. As microfluidic organ chips enable the establishment of tissue-tissue interfaces and simulation of the in vivo microenvironment, we constructed a bone-vessel interface-on-a-chip. Within this physiological model, human bone marrow mesenchymal stem cells (hBMSCs) and human umbilical vein endothelial cells (HUVECs) were successfully co-cultured with high viability. HUVECs formed a confluent monolayer exhibiting selective vascular permeability. Osteo-differentiated hBMSCs expressed alkaline phosphatase, secreted bone-related proteins, and formed mineralized deposits. By introducing the Porphyromonas gingivalis (P. gingivalis) metabolite LPS and the pro-inflammatory factor TNF-α, we established an inflammatory microenvironment. The chip model subsequently exhibited vascular endothelial intercellular junction disruption, upregulated adhesion protein expression, enhanced monocyte adhesion, impaired vascular endothelial barrier function, and reduced bone-related protein expression. These results demonstrate that bone-vessel interface-on-a-chip can effectively study the effects of periodontitis metabolites and pro-inflammatory factors on the vascular barrier and bone tissue through controlled integration of biochemical and biophysical cues. This model provides a robust platform for investigating endothelial cell-targeted therapies for inflammatory diseases, including periodontitis and associated systemic diseases.

Human dental pulp stem cells (hDPSCs) exhibit replicative senescence during in vitro expansion, leading to a reduction in osteogenic differentiation capacity and thereby limiting their potential for bone defect regeneration. Magnesium ion (Mg²⁺), one of the most abundant divalent cations in the human body, is involved in numerous physiological processes. Mg²⁺ deficiency has been closely associated with bone fragility and various systemic aging-related diseases, underscoring its critical role in aging and bone metabolism. However, the effects of Mg²⁺ on mesenchymal stem cells (MSCs) replicative senescence remain poorly understood. In this study, we developed magnesium-doped bioactive glass (Mg-BG) powder with a graded magnesium doping ratio through the sol-gel method, and characterized the pore structure and ion release profiles of each Mg-BG group. We demonstrated that 20 Mg-BG (Mg-BG containing 20 mol% MgO) can effectively reverse the replicative senescence of hDPSCs, improve mitochondrial function, reduce ROS levels and enhance the expression of surface markers associated with differentiation, migration and adhesion in replicatively senescent hDPSCs, thereby enhancing their osteogenic differentiation potential. Furthermore, in vivo experiments using a rat calvarial defect model also confirmed that 20 Mg-BG significantly enhances bone defect repair mediated by replicatively senescent hDPSCs. Mechanistically, we found that the IKBKGP1-mediated NF-κB pathway may play a key role in this process, as revealed by transcriptome sequencing. These findings indicate that Mg-BG could serve as an effective, innovative approach to reverse replicative senescence in hDPSCs and enhance their bone defect repair capabilities.

Chronic diabetic wounds are notoriously difficult to heal due to the self-perpetuating cycle of persistent inflammation and oxidative stress, while current therapies are limited by single-action mechanisms and inefficient drug delivery. This study developed a reactive oxygen species (ROS)/pH dual-responsive hydrophilicity switching intelligent hydrogel (GC-HA@ZIF-8@Cur) by integrating a zeolitic imidazolate framework-8 (ZIF-8) with a dynamically crosslinked hydrogel for synergistic therapy. The system employs inflammation-targeting hyaluronic acid (HA)-modified ZIF-8 nanoparticles (HA@ZIF-8@Cur) to encapsulate curcumin (Cur), which are embedded into a ROS-responsive hydrogel matrix formed by ultraviolet-initiated polymerization of methacrylated gelatin and lipoic acid-grafted chitosan. In the ROS microenvironment of diabetic wounds, oxidation of thioether bonds in the hydrogel to sulfoxide bonds enhanced the hydrophilicity, while acidic conditions induced pH-responsive dissociation of ZIF-8 to cascade-release Cur and Zn²⁺. Experiments demonstrated that GC-HA@ZIF-8@Cur hydrogel reshapes the immune microenvironment by downregulating pro-inflammatory factors (interleukin [IL]-6, tumor necrosis factor [TNF]-α), polarizing macrophages toward the M2 phenotype, and upregulating IL-10, eliminating vascular generation disorders. Additionally, Zn²⁺ promotes vascular endothelial growth factor (VEGF) expression, accelerating angiogenesis. This dual-responsive system achieves spatiotemporally precise drug release, concurrently addressing inflammation, oxidative stress, and vascular regeneration barriers, significantly improving diabetic wound healing efficiency (96.372 ± 0.779% wound closure at day 14). It provides a novel multi-targeted co-delivery strategy for chronic wound therapy.

Liver tissue engineering offers a promising therapeutic strategy for acute liver injury (ALI). Although traditional biomaterial scaffolds exhibit favorable biocompatibility, they still face limitations in the construction of precise structures and the design of functional properties, making it difficult to fully meet the requirements for the repair of specific organs and tissues. In recent years, 3D-printed silk fibroin (3D-SF) scaffolds have demonstrated broad application prospects in tissue and organ repair owing to their excellent biological properties. In this study, a silk fibroin (SF) solution was used as bioink to successfully fabricate 3D-SF scaffolds with fine microarchitectures and mechanical properties matching those of ALI-affected liver tissue, employing a 4K-resolution micro-nano 3D printer integrated with digital light processing technology. In vitro results demonstrated that adipose-derived mesenchymal stem cells (ADSCs) were able to adhere, proliferate and differentiate into hepatocyte-like cells within the 3D-SF scaffolds under specific inductive factors. In vivo, after transplanting 3D-SF onto the liver surface of ALI mice, liver function was partially improved and hepatic injury was repaired. The combination of ADSCs and 3D-SF (ADSCs@3D-SF) significantly enhanced the efficiency of ALI repair. Pathological analysis revealed the formation of vascular and biliary duct-like structures at the scaffold-liver interface. Transcriptomic analysis further indicated that ADSCs@3D-SF upregulated the mRNA and protein expression levels of β-Catenin, LEF1 and Cyclin D1 in the Wnt signaling pathway, promoting cell proliferation and facilitating the recovery from ALI. These findings suggest that ADSCs@3D-SF hold promise as a scaffold candidate for liver tissue engineering, offering a novel strategy for the treatment of liver diseases and the reconstruction of vascular systems.