Journal of Biomaterials Applications最新文献

In the current research, Thioredoxin was loaded into chitosan nanoparticles and then loaded into the matrix of collagen hydrogel containing adipose-derived stem cells (ASCs). In vitro studies including Scanning electron microscopy imaging, cell viability assay, cell migration assay, swelling assay, release assay, radical scavenging assay were performed in order to characterize the dressings. Then, the wound healing activity of these scaffolds were studied in a rat model of wound healing. Our findings indicate that the scaffolds markedly accelerated wound closure, enhanced epithelial regeneration, and increased collagen deposition. The wound closure values for the developed dressings were 60.507 ± 2.287% on Day 7 and 95.270 ± 2.600% on Day 14. ELISA results demonstrated an upregulation of VEGF, b-FGF, and TGF-β expression, while TNF-α and IL-6 levels were significantly reduced. For our developed dressings, VEGF levels were 661.307 ± 80.195 pg/mL, while bFGF was detected at 524.410 ± 81.040 pg/mL. The concentration of TGF-β was 315.357 ± 54.783 pg/mL, and TNF-α was measured at 176.093 ± 43.934 pg/mL. Additionally, IL-6 levels were found to be 187.577 ± 40.860 pg/mL. Our results suggest that our developed hydrogel system has improved wound healing via improving angiogenesis and modulating inflammation. These mechanisms can be attributed to the proangiogenic and immunomodulatory activities of ASCs and the antioxidative properties of Thioredoxin.

In this study, novel silk (SF)-fibroin based scaffolds were fabricated via 3D printing of a thixotropic SF/hydroxypropyl methyl cellulose (HPMC) hydrogel. Two different concentrations of 3D printed SF/HPMC scaffolds (20 wt% and 30 wt%) were implanted subcutaneously in SD rats for 24 weeks to investigate in vivo degradation and biocompatibility. Scaffold morphology, tissue ingrowth (collagen fibers, blood vessels), and local inflammatory responses were assessed using SEM, histology (HE, Masson staining), immunohistochemistry (CD31, CD68), and RT-qPCR (IL-6, IL-1β, IL-10, TGF-β1 mRNA). Results showed that no purulent secretions were found around the two scaffolds during implantation. Collagen fibers, blood vessels and other tissues could grow into the scaffolds after implantation. The number of collagen fibers and CD31-positive vascular endothelial cells in the 20 wt% SF/HPMC scaffolds were greater than that in the 30 wt% SF/HPMC scaffolds. SEM detection showed the pore structure in the cross section of 20 wt% SF/HPMC scaffolds began to collapse at 12 weeks; No obvious collapse of the pore structure was found in the cross section of the 30 wt% SF/HPMC scaffolds during the period of implantation. Mechanical properties test showed that the compressive modulus of 20 wt% SF/HPMC scaffolds decreased significantly at 12 weeks and was lower than that at the pre-implantation. The mechanical properties of the 30 wt% SF/HPMC scaffolds remained relatively stable, and the mechanical properties were slightly higher at 24 weeks than that before implantation. Both scaffolds did not cause severe inflammatory reactions during the degradation process, and their structures could allow the growth of blood vessels, collagen fibers and other tissues. The degradability was correlated to the concentrations of SF/HPMC and insights gained in this study can serve as a guide to match desired degradation behavior with specific applications for the 3D printed SF/HPMC scaffold.

The last two decaes have witnessed significant efforts to develop gelatin/alginate based scaffolds using variants of 3D printing techniques. However, their biocompatibility for regenerating complex soft tissues remains insufficiently explored. Addressing this gap, we fabricated 3D-printed alginate-gelatin (3A5G) and nanocellulose-reinforced (3A5G1C) hydrogel  scaffolds with clinically relevant dimensions (15 mm diameter, 5 mm height) and the host tissue responses were critically analyzed. The distinct advantages of nanocellulose in modulating mechanical strength, viscoelasticity, swelling, and degradation characteristics were established in our prior studies. This investigation aimed to comprehensively evaluate the foreign body response of these scaffolds in a rat model. The animals exhibited healthy metabolic activity, evidenced by progressive weight gain, localized tissue healing, and normal mobility over 30 days. Histological analyses could not reveal any adverse immune reaction at 7- or 30-days, post-implantation. Hematological and serum biochemical assessments indicated a progression from acute (7 days) to sub-acute (30 days) inflammation, following subcutaneous implantation, without any signature of systemic toxicity. Immune marker evaluation (TNF-α, CD-8, CD-68, COX-2, IL-6) confirmed the absence of pathological immune responses, even with nanocellulose incorporation. Immunohistochemical analysis using CD31 staining demonstrated enhanced vascularization in nanocellulose-reinforced scaffolds at both 7 and 30 days. The absence of systemic toxicity from scaffold degradation products and the favorable biocompatibility outcomes underline the potential of these hydrogel scaffolds for soft tissue regeneration. The incorporation of nanocellulose further enhanced the scaffolds' functional performance, particularly in promoting vascularization, positioning them as promising candidates for complex tissue engineering applications.

The incidence of skin cancer has increased significantly in recent decades, highlighting the need for more effective treatments due to the limitations of traditional approaches. This study focused on creating a poly (ε-caprolactone) and chitosan (PCL/CS) nanofibrous scaffold loaded with selenium nanoparticles (Se NPs) and paclitaxel (PTX) to inhibit melanoma cell growth. The synthesized Se NPs, characterized by their uniform spherical shape and nano-scale size (∼120 nm), were incorporated into the scaffold. Then, the Se NPs and PTX were concurrently loaded into PCL/CS nanofibers at 5 wt%, which resulted in fibers with an average diameter of 253 ± 35 nm, presenting a ribbon-like morphology and absence of droplets/beads. The results indicated a high fluid absorption capacity, a wettability and high tensile strength of the produced scaffold. Moreover, the controlled release of the loaded compounds was provided over several days. Remarkably, high toxicity (>90%) and higher levels of apoptosis (>85%) were observed in A375 melanoma cells treated with the PTX-Se NPs PCL/CS scaffold. Moreover, the assessment of fibroblast growth and hemolysis confirmed the scaffold's high level of biocompatibility. The PTX-Se NPs PCL/CS nanofibers exhibit favorable properties and strong anti-tumor efficacy, making them a promising scaffold for localized and selective chemotherapy in anti-melanoma treatment.

Coacervation-responsive cubosomes were prepared by loading a complex of hydrophobically modified hyaluronic acid (HmHA) and hydrophobically modified albumin (HmAlb) and steviol glycoside (SG) into the water channels. Hyaluronic acid and albumin were modified with a lipid chain, and the HmHA and HmAlb were characterized by ¹H NMR and FT-IR spectroscopy, respectively. The formation of the HmHA/HmAlb coacervate complex was optimized when the mass ratio was 1:9 under pH 4.0 conditions. The phase transition temperature of the cubic phase complex was observed to increase slightly from 60.9°C to 61.6°C as a result of the inclusion of the coacervate complex, as evidenced by differential scanning calorimetry. The maximum release degree of SG at 22°C was suppressed to 30.9% due to the coacervate at pH 3, and it was promoted to 75.9% at pH 5.5 due to the dissolution of the electrostatic complex as the pH value increased. The monoolein of the cubosDome enhanced the in vitro skin permeation of the cubosomal SG, as it could play a role as a skin permeation enhancer. The coacervation-responsive cubosome could be potentially used as a drug carrier that can release its content in a pH-controlled manner.

The combination of chitosan and alginate leads to the formation of polyelectrolyte complexes (PECs) that have been mainly used for applications such as wound dressings in biomedical areas. However, processing conditions can affect the resulting complex structure, influencing the final material properties. This work aims to evaluate the influence of processing conditions on the physical-chemical and mechanical properties of chitosan-alginate PEC films for wound dressing applications. The study was carried out using a Box-Behnken design, with controlled variables including pH, agitation speed, amounts of crosslinker and plasticizer, and the type of acid used in chitosan solubilization. Response variables were thickness, liquid absorption capacity, water vapor barrier, and mechanical properties, which are important characteristics in defining the applicability of dressings. All studied factors, as well as their interactions, showed significant effects on the properties of interest. The mathematical models obtained for the studied properties did not have a predictive character but rather a qualitative one, providing a good insight into the behavior of these materials regarding the modification of the evaluated experimental conditions, which strongly influence the characteristics of chitosan-alginate PEC films. Additional swelling and FTIR analyses performed for a selected sub-set of samples confirmed, respectively: (i) the high equilibrium values and stability at the equilibrium of the films regarding liquid absorption for both water and PBS; (ii) no degradation of the chitosan and alginate functional groups or loss of interaction between them under the considered processing conditions.

Oxidative stress arises from an imbalance between excessive production of reactive oxygen species (ROS) and the body's antioxidant defenses. In neurodegenerative diseases, this imbalance leads to ROS accumulation, causing neuronal dysfunction and cell death. Traditional drug therapies often fail to address the dynamic nature of neuroinflammation, limiting their therapeutic efficacy. To overcome this challenge, we have developed an innovative ROS-responsive injectable hydrogel. This hydrogel is designed to detect oxidative stress sensitively and release glutathione in a controlled manner, thereby modulating inflammation and restoring the damaged immune microenvironment to facilitate tissue repair. The hydrogel was synthesized by crosslinking polyvinyl alcohol (PVA) with sodium alginate modified with 3-aminophenylboronic acid (Alg-PBA). We investigated the hydrogel's formation mechanism and analyzed how component variations affect its morphological and rheological properties. Our findings demonstrate that an optimal Alg-PBA to PVA weight ratio of 2:1 yields a hydrogel with superior mechanical strength. Glutathione (GSH) release studies confirmed the hydrogel's pronounced ROS-responsive drug release behavior. Furthermore, biocompatibility assessments revealed that the hydrogel loaded with 100 μg/mL GSH exhibited excellent compatibility and significantly inhibited neuronal apoptosis under oxygen-glucose deprivation (OGD) conditions. This work presents a promising strategy for treating inflammation-related diseases and provides valuable insights for designing next-generation hydrogels that adapt to injury-responsive microenvironments.

A novel design was developed for extrusion based additive manufacturing (robocasting) of bone scaffolds and a numerical study was carried out to find the optimal design to develop a bone scaffold for critical bone defect treatments. Initially, Representative Volume Analysis (RVE) analysis was carried out to predict the Young's modulus (E) of Titanium + Calcium Silicate and Titanium + Hydroxyapatite composites. The RVE analysis outputs were used to find out the E value of various bone scaffold designs and material compositions. The novel stepped design could be used to tailor the mechanical and biological properties of the scaffold by altering the contact support area between strands and changing the pore size, shape and orientation to control the permeability and nutrient transportation. The test revealed that some of the designed scaffolds are suitable for developing scaffolds for cortical bone defects as the E value lies between 10 and 30 GPa. The CFD analysis indicated that some designs do not possess the permeability required for a scaffold to aid nutrient transportation which is ideally between 1.5 × 10^-9 and 5 × 10^-8 m². A sample model was printed and sintered in an argon atmosphere using a microwave furnace to check the feasibility of the process.

Ulcerative colitis (UC) is a chronic, non-specific inflammatory disease affecting the colon and rectum, classified as a type of inflammatory bowel disease (IBD). This study aimed to evaluate the therapeutic effects of Haematococcus carbon dots (HP-CDs) on dextran sulfate sodium (DSS)-induced ulcerative colitis in mice. HP-CDs were synthesized from Haematococcus pluvialis (HP) using a hydrothermal method involving Rhodococcus amphitrite. The effects of HP-CDs on DSS-induced ulcerative colitis in mice were evaluated through histological and pathological analyses. Results demonstrated that HP-CDs significantly alleviated colitis, reducing body weight loss, Disease Activity Index (DAI) scores, and colonic atrophy. Moreover, HP-CDs suppressed MPO activity and decreased the expression of pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6, in colonic tissues. These findings indicate that HP-CDs have potential as a novel therapeutic agent for UC.