Journal of biomedical materials research. Part A最新文献

The excessive accumulation of reactive oxygen species (ROS) and prolonged inflammatory response in diabetic wounds impair neovascularization, resulting in chronic wounds that cause significant pain and financial burden. To address this issue, a novel mucin/tannic acid antioxidant hydrogel (Mu-TA) was developed in a simple and eco-friendly method, leveraging the unique properties of mucin as a hydrogel substrate and the antioxidant capabilities of tannic acid. The in vitro experiments demonstrated that the hydrogel possessed excellent self-healing properties, effective ROS-scavenging capability, and high biocompatibility, significantly mitigating oxidative damage to cells. Furthermore, in the diabetic wound model established in rats, Mu-TA hydrogels downregulated pro-inflammatory factor expression, facilitated the transition of macrophages from the M1 to M2 phenotype, and enhanced neovascularization, thereby accelerating diabetic wound healing. The novel Mu-TA antioxidant hydrogel developed in this study holds significant potential for applications in regenerative medicine and tissue engineering.

Autosomal recessive polycystic kidney disease (ARPKD) is a severe inherited disorder caused primarily by mutations in PKHD1 and in a minority of cases, CYS1. These genes encode fibrocystin and cystin, respectively. ARPKD typically manifests in infancy with enlarged kidneys, progressive cyst formation, and an estimated peri-natal high mortality rate of 20%. Given the lack of efficient therapies and the genetic complexity of many rare diseases such as ARPKD, strategies that restore functional proteins defective in the disease may offer a disease-modifying approach. Urinary extracellular vesicles (uEVs) are naturally secreted by renal and urinary tract cells and contain functional kidney proteins, including fibrocystin and cystin. As such, uEVs may be capable of supplementing these missing proteins and delivering them directly to diseased cells in ARPKD. To investigate the therapeutic potential of uEVs for ARPKD, we first isolated and characterized uEVs from healthy mouse urine by nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and Western blotting for EV markers. PCR confirmed the presence of Cys1 and Pkhd1 mRNAs in uEVs, while cellular uptake was verified by fluorescence microscopy and flow cytometry in collecting duct epithelial cells (mpkCCDc14). In vitro, uEV treatment enhanced Cys1 and Pkhd1 levels in healthy cells, and rescued Cys1 levels in Cys1-deficient cells, derived from Cys1^cpk/cpk (cpk) mice. Upon administration in the cpk mouse model of ARPKD, uEV improved the survival rate in cpk mice. Furthermore, in utero administration of uEVs demonstrated accumulation in the fetal kidney and enhanced Cys1 level following intra-amniotic (IA) administration, highlighting the feasibility of prenatal therapy for the most severe cases of ARPKD that are lethal in utero or within the first 24-48 h after birth. Taken together, our findings reveal that uEVs represent a promising therapeutic modality for ARPKD, capable of restoring deficient CYS1 protein levels and mitigating disease progression.

Biomaterial-based skeletal muscle tissue engineering approaches have largely focused on mimicking the 3D aligned architecture of native muscle, which is critical for guiding myotube formation and force transmission. In contrast, fewer studies incorporate glycosaminoglycan (GAG)-mediated biochemical cues despite their known role in regulating myogenesis and growth factor sequestration. In this study, we develop aligned collagen-GAG (CG) scaffolds using directional freeze-drying and systematically vary GAG type by incorporating GAGs of increasing sulfation levels (hyaluronic acid, chondroitin sulfate, and heparin). While all scaffold variants support myoblast adhesion, metabolic activity, and myotube alignment, heparin-modified CG scaffolds significantly enhance myoblast metabolic activity and myogenic differentiation as measured by myosin heavy chain (MHC) expression and myotube size. We additionally show that heparin-modified scaffolds sequester and retain significantly higher levels of insulin-like growth factor-1 (IGF-1), a potent promoter of myogenesis, compared to other scaffold groups. Together, these results highlight the importance of tailoring GAG type in CG scaffolds for targeted applications and underscore the promise of heparin-modified CG scaffolds as a material platform for skeletal muscle tissue engineering.

The endometrium, the mucosal lining of the uterus, is a highly regenerative tissue that undergoes cyclic remodeling guided by tightly regulated levels of estrogen and progesterone. Stromal cells, including fibroblasts, are embedded within the connective tissue of the endometrium and contribute to the rapidly changing extracellular matrix (ECM). During the secretory phase, high levels of progesterone induce decidualization of endometrial fibroblasts, which changes their morphology and protein secretion. While it has been shown that the mechanical properties of endometrial tissue, such as the elastic modulus, also contribute to tissue homeostasis and pathology, the interplay between hormones and tissue modulus in contributing to ECM remodeling remains unknown. To address this, we used hydrogels of varying elastic moduli (5 and 15 kPa) to induce decidualization of endometrial fibroblasts. Using metabolic labeling of glycosylated nascent ECM proteins, we then visualized and measured the deposition of newly secreted (nascent) ECM proteins during decidualization. In addition, we designed an automated ImageJ-based workflow for unbiased quantification of nascent ECM deposition. Our results demonstrate that both 5 and 15 kPa hydrogels support decidualization of endometrial stromal fibroblasts as shown by an increase in cell flattening and prolactin secretion. While increased hydrogel modulus alone enhances nascent ECM deposition, decidualization produces an additional increase that converges to similar levels regardless of the initial hydrogel modulus. Collectively, these findings demonstrate that endometrial stromal fibroblasts deposit nascent ECM that is enhanced during decidualization. These observations may provide new insights toward future studies addressing the mechanisms of ECM remodeling in endometrial tissue.

Brain tissue is the softest, most viscoelastic tissue in mammals and these mechanical properties strongly influence cell phenotypes. However, conventional hydrogels for 3D cultures rarely provide the ability to tune the elasticity (G') independently of the viscosity (G″), making it impossible to decouple the effects of each mechanical component on cell behavior. To address this deficiency, we have developed a hyaluronic acid (HA)-based, double network hydrogel platform, in which G' and G″ can be tuned independently, keeping G' within the range observed in native brain tissue. The double network hydrogel includes a covalently photocrosslinked HA network (thiolene) to control the elasticity and a dynamically crosslinked HA (hydrazone) network to regulate the viscosity. Addition of the dynamic network to the static single networks increased viscoelasticity, as assessed by the stress-relaxation time and dissipation factor (tan(δ)), of the biomaterial fourfold over that of the covalent network alone, without affecting the storage modulus (G'). The proliferation and spreading of two neural cell types, patient-derived glioblastoma (GBM) tumor cells and mouse neural stem cells (mNSCs), were evaluated in single and double network hydrogels with varying elasticities. An increase in viscoelasticity increased cell proliferation in one patient-derived GBM line, independently of elasticity, while the converse was found in mNSCs. In both GBM and mNSCs cultures, increased cell spreading was observed in stiff double network, compared to stiff single network, gels. This double network hydrogel model allows for the orthogonal tuning of elasticity and viscosity to better represent the mechanics of CNS tissue.

Glioblastoma is the most common primary malignant brain tumor with a 5-year survival rate < 5%. The standard of care involves surgical resection followed by treatment with the alkylating agent temozolomide (TMZ). GBM cells that evade surgery eventually become resistant to TMZ and lead to recurrence of tumors in patients. With only four drugs currently FDA-approved for GBM treatment, there is a need for a clinically relevant model capable of accelerating the identification of new therapies. Microgels are microscale (~10-1000 μm) hydrogel particles that can be used to encapsulate cells in a tailorable 3D matrix. Microdroplets offer short diffusion lengths relative to conventional hydrogel constructs (> 1 mm) to limit spatial distributions of hypoxia and potentially screen therapeutics in a controlled and physiologically relevant environment. Here, we establish a method to encapsulate GBM cells in gelatin and polyethylene glycol (PEG) microgels. We show that microgel composition can affect cell morphology and further, that collections of GBM-laden hydrogels can be used to quantify the effect of single versus metronomic doses of TMZ. GBM metabolic activity is maintained in microgel culture and GBM cells display drug response kinetics similar to previously established literature using macro-scale hydrogel constructs. Finally, we show microgels can be integrated with a liquid handler to enable high-throughput screening using cell-laden microgels.

This study presents a facile and controlled approach for fabricating alginate-based microspheres integrated with biogenic hydroxyapatite (HAp) derived from bovine bone. The direct crosslinking strategy enabled the formation of uniform, stable microspheres that closely replicate the composition and architecture of native bone tissue. Incorporation of biogenic HAp markedly enhanced the physicochemical stability and biological performance of the alginate matrix. The optimized microspheres demonstrated accelerated apatite nucleation within 7 days, indicating superior bioactivity and promoted the rapid sprouting of new blood vessels within 3 h, confirming their proangiogenic potential. These synergistic properties highlight the dual functionality of the developed system in supporting both osteogenic and angiogenic responses. The results further reveal that naturally sourced HAp can effectively replace synthetic analogues, providing a sustainable, cost-effective, and highly bioactive alternative for bone tissue engineering. Overall, this work establishes a simple, eco-conscious fabrication route for multifunctional biomaterials with enhanced mineralization and vascularization potential, paving the way for next-generation regenerative therapies.

In this study, we describe the gelation kinetics, cytocompatibility, and mechanical properties of interpenetrating networks of collagen (COL), fibrin (FIB), hyaluronan (HA), and laminin (LAM) to evaluate their potential to produce mature skeletal muscle tissue. Skeletal muscle is a dynamic tissue that relies on the fusion of myoblasts into multinucleated myofibers to maintain homeostasis. In progressively degenerative conditions, impaired myoblast fusion leads to skeletal muscle atrophy and significant mass loss. Three-dimensional (3D) in vitro models for skeletal muscle disease have been developed to better understand disease mechanisms and facilitate drug screening. However, most rely on Matrigel, a tumor-derived matrix that supports robust cell growth but has limited clinical relevance. To address this limitation, we focused on creating natural, multi-component scaffolds specifically tailored for muscle applications with clinically relevant drug testing use. Using spectrophotometry and rheology, we characterized the gelation kinetics and viscoelastic properties of interpenetrating networks with varying mass ratios of COL to FIB, supplemented with fixed proportions of HA and LAM. Tunable gelation was achieved within a range of 10 to 16 min. Cytocompatibility studies with C2C12 murine myoblasts demonstrated favorable cell viability in 1:1 and 1:2 (w/w) COL:FIB blends incorporating HA and LAM. Immunostaining of differentiated C2C12 cells confirmed Myosin 4 Monoclonal Antibody (MF-20) expression in these blends when seeded into polydimethylsiloxane (PDMS)-anchored bundles. Notably, in cell-laden 1:1 COL:FIB gels with a seeding density of 10 × 10⁶ cells/mL, the compressive modulus increased three-fold between days 4 and 7 of differentiation. These findings highlight the potential of COL:FIB interpenetrating networks, enhanced with HA and LAM, as promising scaffolds for developing clinically relevant models of skeletal muscle tissue.

Postoperative infections remain a major complication after spinal fusion surgery, often caused by biofilm-forming bacteria that resist short-term antibiotic prophylaxis. Vancomycin (VAN) is sometimes delivered locally during surgery; however, levels diminish rapidly, leaving patients vulnerable to late-onset infections. We developed a composite hydrogel integrating perfluorohexane-based emulsions within alginate or fibrin matrices to enable both sustained and ultrasound-triggered VAN release. Water-in-oil-in-water emulsions were prepared using fluorosurfactant-stabilized perfluorohexane as the volatile oil phase, then embedded in hydrogels and exposed to ultrasound (2.5 MHz, 5.5 MPa peak negative pressure) to initiate acoustic droplet vaporization for triggered release. Drug release was quantified spectrophotometrically and with fluorescent-labeled VAN, while antibacterial efficacy was tested against Staphylococcus aureus. Hydrogels directly loaded with free VAN exhibited burst release (~55%-67% within 24 h) followed by limited sustained release, which is suboptimal for prolonged coverage. In contrast, emulsion-loaded hydrogels reduced premature leakage, retaining > 70% VAN on Day 1 and providing gradual baseline release. Ultrasound application enhanced VAN release up to 8.75-fold in alginate and 27.5-fold in fibrin hydrogels after 7 days (p < 0.0001), supporting both continuous and on-demand delivery. Only alginate-emulsion hydrogels showed measurable antibacterial activity, as drug-matrix interactions in fibrin prevented release; ultrasound-treated samples displayed significantly greater efficacy over 7 days (p < 0.05 vs. no ultrasound). This dual-mode delivery platform enables spatial and temporal control of VAN release, combining early prophylaxis with ultrasound-triggered reinforcement, and holds promise for improving infection prevention in orthopedic surgeries by aligning drug delivery with clinical timelines.

This study aimed to develop electrospun thermoplastic polyurethane (TPU) membranes incorporating ciprofloxacin (CIP)-loaded montmorillonite (MMT) nanoclays to achieve controlled antibiotic release for wound healing applications. CIP was intercalated into MMT and then dispersed homogeneously within the TPU matrix to fabricate nanofibrous membranes via electrospinning. Structural and chemical analyses using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) confirmed successful drug intercalation and interactions among CIP, MMT, and TPU. Morphological characterization by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) revealed uniform, bead-free fibers with well-dispersed additives. Drug release studies showed that CIP-loaded MMT membranes exhibited significantly slower and sustained release (12.4%-20.8% over 6 days) compared to membranes with CIP directly embedded in TPU (59.1%-73.4%), indicating effective modulation of release kinetics by MMT. Cytotoxicity tests on 3T3 fibroblasts demonstrated good biocompatibility of pure TPU membranes (> 85% viability), while MMT-containing membranes showed reduced cell viability over time, suggesting potential dose-dependent effects. Antibacterial assays confirmed that only CIP-containing membranes inhibited Staphylococcus aureus and Escherichia coli growth, with no activity observed in pure TPU or TPU/MMT controls. Overall, the results indicate that CIP-loaded MMT electrospun TPU membranes provide a promising platform for sustained drug delivery and antibacterial activity in wound dressing applications.