Engineering biomimetic scaffolds for bone regeneration: Chitosan/alginate/polyvinyl alcohol-based double-network hydrogels with carbon nanomaterials

Multifaceted role of nanocomposite hydrogels in diabetic wound healing: enhanced biomedical applications and detailed molecular mechanisms

The complex microenvironment of diabetic wounds, which is characterized by persistent hyperglycemia, excessive inflammatory responses, and hypoxic conditions, significantly impedes the efficacy of traditional hydrogels. Nanocomposite hydrogels, which combine the high-water content and biocompatibility of hydrogels with the unique functionalities of nanomaterials, offer a promising solution. These hydrogels exhibit enhanced antibacterial, antioxidant, and drug-release properties. Incorporating nanomaterials increases the mechanical strength and bioactivity of hydrogels, allowing for dynamic regulation of the wound microenvironment and promoting cell migration, proliferation, and angiogenesis, thereby accelerating wound healing. This review provides a comprehensive overview of the latest advances in nanocomposite hydrogels for diabetic wound treatment and discusses their advantages and molecular mechanisms at various healing stages. The study aims to provide a theoretical foundation and practical guidance for future research and clinical applications. Furthermore, it highlights the challenges related to the mechanical durability, antimicrobial performance, resistance issues, and interactions with the cellular environments of these hydrogels. Future directions include optimizing smart drug delivery systems and personalized medical approaches to enhance the clinical applicability of nanocomposite hydrogels.

Investigation the behavior of different fullerenes on graphene surface

In the present study, the regime of motion of fullerene molecules on graphene substrate in a specific temperature range is investigated. The potential energy of fullerene molecules is analyzed using classical molecular dynamics methods. Fullerene molecules C36, C50, C60, C76, C80, and C90 are selected due to spherical shapes of different sizes and good motion performance in previous studies. Analysis of the motion regime at different temperatures is one of the main objectives of this study. To achieve this aim, the translational and rotational movements of fullerene molecules are studied independently. In the first step of the investigation, Lennard-Jone's potential energy of fullerene molecules is calculated. Subsequently, the motion regime of different fullerenes is classified based on their displacement and diffusion coefficient. Findings indicate C60 is not appropriate in all conditions. However, C90 and C76 molecules are found to be appropriate candidates in most cases in different conditions. As far as a straight-line movement is considered, the deviation of fullerene molecules is compared by their angular velocities. Although C60 has a lower angular velocity due to its symmetrical shape, it may not move well due to its low diffusion coefficient. Overall, our study helps to understand the performance of different fullerene molecules on graphene substrate and find their possible applications, especially as wheels in nanomachine or nanocarrier structures.

Fabrication of gelatin-based antibacterial bilayer wound dressing using direct writing and electrospinning methods

Fabricating a fibrous well-ordered wound dressing for accelerating full-thickness wounds is a desirable treatment vector. Here, through modifications in the material extrusion device and adding a pneumatic-based injection, a material extrusion method for gelatin was introduced with the ability to fabricate 3D structure with repeat layers to support cell activity for the under layer. Furthermore, in the upper layer, the co-electrospinning of PU with gelatin was designed to simultaneously exploit the oxygen permeability and mechanical stability of PU with regenerative properties and collagen-like structure of gelatin. Moreover, zinc oxide nanoparticles (ZnO) was added into the 3D-printed under layer to synergistically benefit from the antibacterial properties of ZnO and the excellent biocompatibility of gelatin. The controllable porosity of the under layer, enabled through the additive manufacturing method, was adjusted to mimic the extracellular matrix of natural tissue with around (127.28 ± 20.70) μm pore size after swelling with smooth fibers. S. aureus, E. coli, Bacillus subtilis, and Pseudomonas with inhibition zone diameters at ∼ 2.14 cm and ∼ 1.96 cm, ∼ 4.01 cm, and ∼ 2.24 cm, respectively. Moreover, the scaffold showed great biocompatibility toward fibroblast cells after 7 days of cell culture with ∼ 89 % cell viability.