Staff

Abstract:
Bacterial keratitis (BK) is a severe eye infection commonly associated with Staphylococcus aureus (S. aureus), posing a significant risk to vision, especially among contact lens wearers. This research introduces a novel smart nanoplatform (deMS@cNF), developed from demineralized mussel shells (deMS) and reinforced with chitin (CT) nanofibrils, specifically designed for portable photothermal disinfection of contact lenses. The nanoplatform leverages the photothermal properties of eumelanin in mussel shells (MS), which, when activated by a simple bike flashlight, rapidly heats to temperatures up to 95 °C, effectively destroying bacterial contamination. In vitro tests demonstrate that the nanoplatform is biocompatible and non-toxic, making it suitable for medical applications. This study highlights an innovative approach to converting marine biowaste into a safe, effective, and low-cost portable method for disinfecting contact lenses, showcasing the potential of the deMS@cNF platform for broader antimicrobial applications.

Abstract:
Hierarchical nanostructures fabricate by electrospinning in combination with light-responsive agents offer promising scenarios for developing novel activable antibacterial interfaces. This study introduces an innovative antibacterial face mask developed from poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers integrated with indocyanine green (ICG), targeting the urgent need for effective antimicrobial protection for community health workers. The research focuses on fabricating and characterizing this nanofibrous material, evaluating the mask's mechanical and chemical properties, investigating its particle filtration, and assessing antibacterial efficacy under photothermal conditions for reactive oxygen species (ROS) generation. The PHBV/ICG nanofibers are produced using an electrospinning process, and the nanofibrous construct's morphology, structure, and photothermal response are investigated. The antibacterial efficacy of the nanofibers is tested, and substantial bacterial inactivation under both near-infrared (NIR) and solar irradiation is demonstrated due to the photothermal response of the nanofibers. The material's photothermal response is further analyzed under cyclic irradiation to simulate real-world conditions, confirming its durability and consistency. This study highlights the synergistic impact of PHBV and ICG in enhancing antibacterial activity, presenting a biocompatible and environmentally friendly solution. These findings offer a promising path for developing innovative face masks that contribute significantly to the field of antibacterial materials and solve critical public health challenges.

Abstract:
The cartilage tissue is neither supplied with blood nor innervated, so it cannot heal by itself. Thus, its reconstruction is highly challenging and requires external support. Cartilage diseases are becoming more common due to the aging population and obesity. Among young people, it is usually a post-traumatic complication. Slight cartilage damage leads to the spontaneous formation of fibrous tissue, not resistant to abrasion and stress, resulting in cartilage degradation and the progression of the disease. For these reasons, cartilage regeneration requires further research, including use of new type of biomaterials for scaffolds. This paper shows cartilage characteristics within its most frequent problems and treatment strategies, including a promising method that combines scaffolds and human cells. Structure and material requirements, manufacturing methods, and commercially available scaffolds were described. Also, the comparison of poly(L-lactide) (PLLA) and polyethersulfone (PES) 3D membranes obtained by a phase inversion method using nonwovens as a pore-forming additives were reported. The scaffolds' structure and the growth ability of human chondrocytes were compared. Scaffolds' structure, cells morphology, and protein presence in the membranes were examined with a scanning electron microscope. The metabolic activity of cells was tested with the MTT assay. The structure of the scaffolds and the growth capacity of human chondrocytes were compared. Obtained results showed higher cell activity and protein content for PES scaffolds than for PLLA. The PES membrane had better mechanical properties (e.g. ripping), greater chondrocytes proliferation, and thus a better secretion of proteins which build up the cartilage structure.

Keywords:
3D-scaffolds, membrane structure, polyethersulfone, poly(L-lactide), chondrocyte culture, cartilage regeneration

Abstract:
Biodegradability or materials physicochemical stability are the key biomaterials selection parameters for various medical and tissue engineering applications. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a natural copolymer known from its biocompatibility with great support for cells growth and attachment on films and fibers. In our studies, the physicochemical properties of electrospun PHBV fibers and spin-coated films aged for 1, 4 and 8 weeks were analyzed using bulk (FTIR) and surface chemistry (XPS) methods and water contact angle. Further, we characterized the zeta potential changes after aging, by means of electrokinetic measurements, and cell responses to it, using NIH 3T3 murine fibroblasts. Colorimetric MTS cell viability test allowed the assessment of cell proliferation. Additionally, the morphology of fibroblasts and biointerfaces were studied by confocal laser and electron scanning microscopy (CLSM and SEM). These studies indicated that the activity, attachment and proliferation of fibroblasts is independent of aging of PHBV fibers and films. PHBV films show very stable zeta potential over 8 weeks of aging, opposite to PHBV fibers. Importantly, the flat film of PHBV increases cell proliferation, while the fibrous meshes are an excellent support for their stretching. The results of the study revealed clear advantages of PHBV films and fibrous meshes in cell-material interaction.

Keywords:
cell morphology, fibroblast, electrospun fibers, PHBV, Zeta potential