Biomedical materials (Bristol, England)最新文献

Pollen grains are being explored as innovative biomaterials for different applications, ranging from oral drug delivery to encapsulation of food additives, with the production of pollen-based building blocks standing on its robust, chemically inert, and mechanically durable sporopollenin wall. Yet, concerns remain regarding the safety of sporopollenin microcapsules (SMCs) or derivatized sporopollenin materials purified from pollen grains, traditionally linked to allergies. Herein, we address the critical question of whether sporopollenin shells purified from bee pollen may cause allergic reactions by evaluating their interaction with human immunoglobulin E (IgE) antibodies in sera from patients with and without allergic sensitization to pollen of specific species. Clean SMCs fromCastanea sativa, Amaranthaceae (Chenopodium album), andOlea europaeapollen grains were successfully produced using a species-independent chemical treatment and characterized. The Covaris Adaptive Focused Acoustics™ (AFA) technology was employed for protein extraction from the bee pollen and the SMCs, yielding 0.72-1.25 ng and 0.026 ng-0.028 ng of protein per pollen grain, respectively. X-ray photoelectron spectroscopy (XPS) analysis also confirmed that the surface nitrogen content of the SMCs was minimal, ranging from 0.9% to 2.7%. SDS-PAGE, followed by immunoblotting analysis, showed that proteins extracted from bee pollen strongly reacted with IgE antibodies in human sera, whereas SMCs did not trigger allergic sensitization. Overall, our findings suggest that while bee pollen proteins could elicit allergic reactions in sensitive patients, SMCs do not, highlighting their potential as safe biomaterials for various applications and offering valuable insights into the allergenic potential of bee pollen.

Avascular necrosis (AVN) is a bone degenerative condition characterized by disrupted blood supply, leading to bone necrosis and subsequent bone collapse. Current AVN treatments, such as core decompression and surgical interventions, exhibited limited success rates due to donor site morbidity, infection, and structural mismatch. Existing treatments fail to regenerate the necrotic bone and prevent bone collapse. Thus, the current study explores the potential of 3D-printed composite scaffolds consisting of calcium peroxide nanoparticles (CaO₂NPs) and manganese dioxide (MnO₂) within a polylactide (PLA) matrix. These 3D-printed composite scaffolds can provide mechanical support to the collapsing bone, while CaO₂NPs and MnO₂particles can provide a localized and sustained molecular oxygen delivery at the site of necrosis. PLA/Mn/Ca4% exhibited the highest mechanical strength compared with other tested compositions (2% and 6%). Moreover, the 4% composition demonstrated consistent and sustained oxygen release.In vitrostudies with MG-63 cells demonstrated excellent biocompatibility and cell proliferation under hypoxic conditions. Also, enhanced mineralization on the 4% composite scaffolds suggested osteogenic potential of these scaffolds in a hypoxic environment. These findings suggest that these 3D printed composite scaffolds can effectively promote bone regeneration in hypoxic conditions, potentially offering a promising clinical strategy for treating AVN.

Three-dimensional (3D) cell printing is rapidly redefining how we engineer tissues by enabling the precise delivery of living cells within bio-inks to build complex, cell-laden structures. Unlike traditional approaches that seed cells onto inert scaffolds, this technique allows direct integration of cells into the construct, promoting enhanced cell infiltration, extracellular matrix (ECM) remodeling, and tissue-like functionality. Despite the explosion of interest, the field remains fragmented, with limited efforts to unify emerging data across platforms and applications. Our review addresses this gap by synthesizing recent advances in 3D cell printing in terms of key printing factors and parameters and adaptive bioprinting, presenting consensus and translative information such as printing parameters, identifying current established applications, and proposing future research directions based on the currentin vivoor clinical results. We map current trends across biomaterial choices-including gelatin, decellularized ECM, alginate, collagen I, and fibrin-and explore how diverse cell types, from primary human cells to engineered stem cell derivatives, are shaping the future of tissue fabrication. These innovations are already influencingin vivoresearch in skin regeneration, cartilage repair, and vascular grafts, while the high-resolution capabilities of 3D printing are powering next-generation organ-on-chip models. We conclude with key translational challenges and propose future research priorities to move from bench to bedside.

Bioceramic-incorporated polymer-based scaffolds have gained more interest as a promising and effective approach in bone tissue engineering (BTE) applications. This study is the first to investigate the role of incorporated manganese-doped hydroxyapatite (Mn-HA) and gelatin coating in increased bioactivity and biological properties, specifically the cell attachment potencies of three-dimensional (3D) porous electrospun polycaprolactone (PCL). In this context, novel 3D porous composite scaffolds were synthesized by wet electrospinning of PCL incorporated with Mn-HA. The scaffolds were then coated with a thin gelatin layer to enhance the cell adhesion capacity. The effects of Mn-HA and the gelatin coating were evaluated in terms of structural, physicochemical, and biological properties. The results demonstrated that Mn-HA was successfully synthesized with doping of 2 mol% Mn, with MnSO₄(manganese sulfate) and MnCl₂(manganese chloride) precursors. Mn-HA powder with a MnSO₄precursor indicated better cell viability results. Therefore, Mn-HA/PCL scaffolds with 2.5% and 5% (w/w) bioceramic content were prepared with the MnSO₄precursor. The scaffolds' porosity increased from 24% (PCL/gelatin group) to approximately 34% in both the 2.5% and 5% (w/w) bioceramic-containing groups. The addition of Mn-HA powder improved thein vitrobioactivity and degradation rate of the scaffolds. Specifically, the 5% and 2.5% (w/w) Mn-HA incorporated scaffolds indicated 40% and 30% weight loss after 21 d of incubation, respectively. In contrast to the PCL/gelatin and HA-containing groups, the Mn-doped HA containing scaffolds exhibited a weight loss of around 17%-20%, indicating a decrease in degradation. The presence of the Mn-HA powder and gelatin coating elevated the cell viability results significantly, as opposed to the PCL scaffolds. Incorporation of 5% (w/w) Mn-HA improved the alkaline phosphatase activity and intracellular calcium levels, contrary to other groups. Thus, the incorporation of Mn-doped HA and gelatin into the PCL scaffold supports the potency towards properties required for BTE applications and suggests it as a prospective biomaterial for further evaluations.

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.