Biomedical materials (Bristol, England)最新文献

Chronic wounds represent a significant clinical challenge, necessitating the development of multifunctional dressings with bioactive compounds to accelerate healing. Carotenoids-natural pigments with potent antioxidant and anti-inflammatory properties-are emerging as promising agents for tissue repair. This study explores the therapeutic potential of carotenoid pigments biosynthesized by Kocuria sp. and their integration into a chitosan/alginate/polyvinyl alcohol (Cs/Alg/PVA) nanocomposite for wound healing applications. Carotenoids were extracted and optimized under varying conditions of temperature, salinity, pH, and culture media. The pigments were incorporated into a Cs/Alg/PVA matrix and characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry (DSC), andin vitrorelease studies. Antioxidant capacity was evaluated via DPPH assay, and anti-inflammatory properties were assessed using hemolysis assays. Cell viability and proliferation were analyzed on L929 and human dermal fibroblast cells using MTT assay.In vivowound healing efficacy was evaluated in a murine excisional wound model with histological and morphometric analyses. The carotenoid-enriched composite exhibited strong antioxidant activity, significant anti-hemolytic effects, and enhanced biocompatibility with fibroblasts. Release kinetics revealed sustained and pH-responsive delivery of carotenoids.In vivo, the composite significantly accelerated wound contraction and epithelialization compared to controls, with histopathological analysis confirming increased fibroblast presence, collagen deposition, and reduced inflammation. This study highlights the therapeutic potential of microbial carotenoids embedded in Cs/Alg/PVA dressings as a biocompatible, antioxidant-rich platform for enhanced wound healing. The approach offers a sustainable, natural alternative to synthetic additives in wound care biomaterials.

Bone formation is a dynamic process, while the stiffness of extracellular matrix increases dynamically during bone maturation. Matrix stiffness can significantly regulate the stem cell differentiation and bone repair. It is particularly important to develop dynamic stiffness scaffolds to simulate dynamic mechanical microenvironment for bone repair. This study proposed a novel method to achieve dynamic improvement of scaffold stiffness by mineralization, which is a natural process of bone matrix dynamic stiffening. The decalcified bone matrix (DBM)/collagen (Col)/silicon-substituted hydroxyapatite (SiHA) scaffold was constructed by coating the Col/SiHA on the surface of DBM. When the scaffolds contacted with body fluid, the stiffness of scaffolds were enhanced by mineralization, increasing from 9.10 ± 4.42 kPa to 19.77 ± 9.66 kPa in the DBM/Col scaffold and from 40.54 ± 6.25 kPa to 69.40 ± 8.76 kPa in the DBM/Col/SiHA scaffold. The experimental results proved that the DBM/Col/SiHA scaffold with dynamic stiffness had good biocompatibility and could promote the osteogenic differentiation of mesenchymal stem cell. The DBM/Col/SiHA scaffold, when implanted in a rat calvarial defect model, further enhanced bone regeneration and integration, as evidenced by a bone mineral density reaching 285.592 ± 19.611 mg HA ccm^-1at 12 weeks. This research may provide new insights into the application of mineralization-dependent stiffening scaffolds in bone tissue engineering.

Conductive materials play a crucial role in enhancing functional performance in muscle tissue engineering. This study investigates the impact of the conductive polymer polyaniline (PANi) in Polycaprolactone (PCL)-collagen Type I (PCL-collagen I) nanofiber scaffolds designed to support the coculture of human adipose-derived stem cells (ADSCs) and myoblasts (Mbs). The effect of varying PANi concentrations (0%, 2%, 4%, 6%) in PCL-collagen I nanofiber scaffolds was evaluated concerning the cell alignment, differentiation and gene expression of cocultured Mbs and ADSC. Nanofiber scaffolds with different PANi concentrations were analyzed. Acetic acid was used as a non-toxic and biocompatible solvent for electrospinning the nanofibers.In vitroexperiments involved a 1:1 coculture of Mbs and ADSCs for up to 28 d on the scaffolds. The cell viability, differentiation and myotube morphology were assessed using live-dead-assay, CCK-8-assay, immunofluorescence staining and gene expression analysis. Scaffolds with 2% and 4% PANi showed a higher percentage of live cells compared to the control at both 7 and 28 d. The nanofibers with 2%, 4% and 6% PANi concentration showed promising results in terms of cell differentiation and myotube morphology. After 14 d, the scaffolds with 4% PANi showed superior cell differentiation with strong myotube alignment along the nanofibers. At higher PANi concentrations (6%), only the myotube width increased significantly, whereas 4% PANi resulted in a markedly higher myotube number. PCL-collagen I nanofibers incorporating PANi enhance myoblast alignment and differentiation compared to the control group, showing promise for muscle tissue engineering applications. The non-toxic solvent makes the nanofibers suitable for translational purposes. Furtherin vivostudies are needed to explore the full impact on cellular function and regeneration.

This study aimed to characterize periosteal formation and remodeling activity by stereological quantification of osteoblasts, osteoclasts, and osteocytes in autograft blocks and human cortical shells (HCS), providing a histological basis for bone regeneration procedures. Eight male New Zealand white rabbits received paired 5 mm calvarial defects filled with either autograft blocks or mineralized freeze-dried, gamma-irradiated HCSs, after complete periosteum removal to ensure de novo healing. After 12 weeks, the specimens were harvested, and osteoblast, osteoclast, and osteocyte densities were quantified using the optical dissector method. Statistical analyses were performed using pairedt-tests. All grafts were well integrated with healthy soft tissues and had no complications. HCSs more frequently contained immature woven bone, whereas autografts predominantly contained mature lamellar bone. Osteoblast and osteoclast densities showed no significant differences between the groups, but the autografts exhibited significantly higher osteocyte density (p= 0.0026). Mineralized freeze-dried, gamma-irradiated HCSs support de novo periosteal regeneration and remodeling activity comparable to that of autograft blocks despite processing-related devitalization. While autografts mature faster, host-driven periosteal repair may offset the graft deficits over time. These findings provide preliminary histological evidence of the clinical potential of allogeneic bone regeneration, warranting further long-term studies.

Degenerative disc disease is a leading cause of chronic back pain, and current surgical treatments such as fusion and disc arthroplasty remain limited by implant wear, stress shielding, and mechanical mismatch with the native intervertebral disc (IVD). This study investigates three-dimensional (3D) printed thermoplastic polyurethane (TPU) Gyroid structures as biomimetic disc replacements. Using filaments of varying stiffness, 3D-printed constructs demonstrated high geometric fidelity and mechanical performance within physiological load and deformation ranges. Dynamic compression testing revealed damping coefficients of approximately 16%, closely matching native IVD behavior. Stiffness scaled predictably with structural density, allowing mechanical tuning toward physiological properties. These findings highlight the potential of Gyroid-structured TPU implants to replicate the natural damping and load distribution of human discs, offering a pathway toward customizable, patient-specific disc replacements. Future work will focus on medically approved TPU, biological responses, and multiaxial loading.

Myelination is a critical biological process in which Schwann cells form myelin sheaths around axons to support signal transmission and nerve regeneration. Artificial axon models can provide a useful tool for studying the process of myelination. Here, we present a high-throughput microdevice featuring ordered, suspended polydimethylsiloxane microfibers generated through mechanical stretching of micropillars. The device provides a biocompatible and optically transparent platform that facilitates cell culture, live imaging, and quantification of myelin formation. S42 Schwann cells cultured on the microfibers formed myelin sheaths that were visualized using fluorescence microscopy. Moreover, increased myelination induced by progesterone and IL-12 p80 was observed, demonstrating the potential of the device for drug screening. This three-dimensional myelination culture chip provides a robust and accessible tool for studying peripheral nerve repair and therapeutic development.

Utilization of cell derived decellularized extracellular matrices (dECM) is a highly versatile way to introduce complex cell specific native-like microenvironment in vitro. While dECMs have been used in various applications, surface functionalization of biomaterials with cell-derived dECMs that maintain their structural integrity for investigating cell behavior is rarely reported. In this study, we developed and characterized a platform combining native bone surface topography mimicked polydimethylsiloxane (BSM PDMS) surfaces with pre-osteoblast derived dECM to mimic both physical and biochemical cues of the bone microenvironment. Decellularized ECM on PDMS and BSM PDMS surfaces preserved their structure and specific matrix components, in addition to having a significant influence on microscale surface topography. Recellularization of BSM PDMS + dECM surfaces supported cell attachment and proliferation of both pre-osteoblasts and adipose derived mesenchymal stem cells (hADMSC). BSM PDMS + dECM surfaces showed significantly elevated glycosaminoglycan (GAG) content, as well as, resulted in induction and topography dependent calcification of hADMSCs. Osteogenic induction and dECM presence on BSM PDMS synergistically increased RUNX2 expression of hADMSCs while keeping YAP expression relatively unaltered. This work provides insights for designing biomimetic platforms integrating biochemical and biophysical cues for advanced bone tissue engineering.

The development of injectable and printable conductive hydrogels is of great importance for tissue engineering, particularly for supporting the regeneration of electrically active or excitable tissues. In this study, a nanocomposite hydrogel was formulated by incorporating reduced graphene oxide (rGO) into a self-healing andin situ-gelling aldehyde-functionalized xanthan gum (AXG) and gelatin (Gel) matrix. The AXG-Gel hydrogels incorporated by 0, 0.5, 1, and 2% w/v rGO were synthesized using Schiff-base chemistry and evaluated for its physicochemical, mechanical, rheological, electrical, and biological properties. The 1% rGO formulation exhibited the highest mechanical modulus (0.315 ± 0.0135 MPa) and self-healing yield (93.18 ± 1.56%), compared to 0.2157 ± 0.0145 MPa and 77.16 ± 5.98% in the 2% rGO formulation. By an increase in rGO content, an increase in porosity was observed, holding values from 90.43% in rGO-free scaffolds to 97.70% in the 2% rGO group. All samples maintained high swelling capacities (>800%), with AXG-Gel-0.5rGO showing the highest (∼940%) and AXG-Gel-2rGO the lowest (∼830%). Conductivity improved significantly in the 1% rGO hydrogel, achieving 4.16 × 10²S/m which was 24% higher than the rGO-free scaffold (3.33 × 10²S m^-1). Impedance spectroscopy showed reduced resistance and higher charge transfer efficiency in rGO-loaded scaffolds. The AXG-Gel-1rGO also exhibited favourable rheological behavior, with a storage modulus of 1.7 kPa at 1 Hz and pronounced shear-thinning. The injectability and printability were confirmed by syringe injection assay and extrusion-based 3D printing of circular structure. MTT and SEM-based cytocompatibility assays confirmed an excellent viability and cell adhesion for AXG-Gel-1rGO scaffolds after 3 d. Overall, the 1% rGO scaffold achieved a balanced combination of conductivity, printability, injectability, porosity, mechanical strength, and cytocompatibility, indicating its potential as a promising candidate for future electrically active tissue engineering applications.

Chemotherapy is an anti-cancer treatment that uses chemical drugs to suppress rapidly growing cancer cells. Nevertheless, low water solubility and poor pharmacokinetics of chemotherapeutic drugs can reduce therapeutic efficacy and limit the duration of drug action due to rapid clearance from the body. Furthermore, systemic chemotherapy can attack not only cancer cells but also normal cells, inducing severe side effects. In this study, Tri-GalNAc-decorated RNA nanoparticles (RNAPs) loaded with doxorubicin (Dox-TG-RNAP) were developed to treat hepatocellular carcinoma (HCC). The surface of RNAP was decorated with avidin and biotin-Tri-GalNAc sequentially using electrostatic and non-covalent interactions. Dox-TG-RNAP had a high loading capacity of Dox and delivered Dox to HCC cells specifically through asialoglycoprotein receptor (ASGPR)-mediated endocytosis. Consequently, Dox-TG-RNAP induced apoptosis selectively in HCC cells expressing ASGPR, while minimizing cytotoxicity in non-ASGPR-expressing cells such as HDF cells. Such ligand-modified RNAPs facilitated targeted drug delivery effectively to a range of tissues through surface functionalization with diverse ligands, thereby mitigating off-target effects.