Colloids and Surfaces B: Biointerfaces最新文献

Skin wounds are a major health problem of global concern. Prompt and proper care after skin injury is crucial for rapid healing and minimizing scar. Hydrogels are widely used wound dressings in clinical practice due to their ability to create a moist environment for wound healing. However, most hydrogels exhibit high swelling ratio and tend to compress and irritate the wound upon contact with wound exudate, which is counterproductive to the wound healing process. Supramolecular hydrogels formed by self-assembly of natural drug molecules have attracted increasing interest in wound healing due to their intrinsic pharmacological activity and excellent biocompatibility. In this study, a supramolecular nanofiber network hydrogel based on glycyrrhetinic acid (GA) was developed to promote wound healing. The hydrogel network consists of a self-assembled nanofibrous network generated by GA and a cross-linked network formed by gellan gum (GG). The resulting hydrogels have unique low swelling properties as well as good mechanical stability. What's more, the GG/GA hydrogels can absorb water and return to its original state after lyophilization, which facilitates storage. Both in vitro and in vivo studies demonstrated high biocompatibility and significant pro-angiogenic effects of GG/GA hydrogel. The wound healing ratio of the rat model treated with GG/GA hydrogel reached 95.49 ± 1.1 % at 14 days. These findings indicate that GG/GA supramolecular hydrogels possess significant potential in promoting wound healing and offer a novel approach for creating low-swelling, easy storage, inherently physiologically active, and highly biocompatibility wound dressings.

For cancer patients with a high risk of ovarian tissue metastasis, ovarian autotransplantation is not advised due to the potential spread of malignant cells. Ex vivo purging of ovarian fragments may offer a more suitable alternative for fertility restoration. Eradicating malignant cells should be done selectively without affecting follicles or ovarian stromal cells (SCs). As a clinically licensed method, photodynamic therapy (PDT) is a minimally invasive treatment to destroy cancer cells. This study evaluates the effectiveness of nanoemulsions (NE) containing two phthalocyanine photosensitizers; aluminum (III) phthalocyanine (AlPc) and zinc (II) phthalocyanine (ZnPc) in eliminating cancer cells. Human leukemic malignant (HL-60) and ovarian stromal cells (SCs) were treated with AlPc/ZnPc loaded NEs with or without diode laser irradiation. HL-60 leukemia cells in 2D culture were eliminated by treatment with 10 nM AlPc-NE or 0.1 µM ZnPc-NE, while no toxicity was observed in SCs. In 3D culture models, although the cells showed more resistance to the NEs as a result of limited oxygen and photosensitizer penetration, the treatment remained selective for cancer cells. These approaches have the potential to eliminate malignant cells from ovarian tissue fragments.

Citrus peel waste carbon dots based on nitrogen-doped (N-TanCD) were developed by a hydrothermal strategy to deliver active packaging fillers and characterized by transmission electron microscopy, photoluminescence, and Fourier transform infrared analyses. The addition of N-TanCD into chitosan-pululan (CS/Pul@N-TanCD) polymer blend amplified the tensile strength of the composite film by 22.8 %, whereas the antioxidant activities against DPPH and ABTS reached 62.7 % and 91.6 %, respectively. The proposed film showed blocked 98.8 % of UV-A and 100 % of UV-B without affecting the film's transparency. The CS/Pul@N-TanCD film lowered the contamination of L. monocytogenes and E. coli by more than 4 and 5 log CFU/mL, respectively. Sliced bread was packaged using CS/Pul-based films and stored for 12 days at 50 % relative humidity and 25 °C to investigate changes in the quality of the bread. It was found that bread packaged with CS/Pul film integrated with N-TanCD maintained excellent bread quality relating to appearance, moisture content, hardness, weight loss, and total viable bacterial count.

Biomaterial-associated infections pose severe challenges in modern medicine. Previously, we reported that polyanionic DNA surface coatings repel bacterial adhesion and support osteoblast-like cell attachment in monoculture experiments, candidate for orthopaedic implant coatings. However, monocultures lack the influence of bacteria or bacterial toxins on osteoblast-like cell adhesion to biomaterial surfaces. In this study, co-culture of staphylococcus (S. epidermidis and S. aureus) and SaOS-2 osteosarcoma cells was studied on chitosan-DNA polyelectrolyte multilayer coated glass based on the concept of `the race for the surface`. Staphylococcus was first deposited onto the surface in a microfluidic chamber to mimic peri-operative contamination, and subsequently, SaOS-2 cells were seeded. Both staphylococcus and SaOS-2 cells were cultured together on the surfaces for 24 h under flow. The presence of S. epidermidis decreased SaOS-2 cell number on all surfaces after 24 h. However, the cells that adhered spread equally well in the presence of low virulent S. epidermidis. However, highly virulent S. aureus induced cell death of all adherent SaOS-2 cells on chitosan-DNA multilayer coated glass, a worse outcome than on uncoated glass. The outcome of our co-culture study highlights the limitations of monoculture models. It demonstrates the need for in vitro co-culture assays to meaningfully bridge the gap in lab testing of biomaterials and their clinical evaluations where bacterial infection can occur. The relative failure of cell-adhesive and bacteria-repelling DNA coatings in co-cultures also suggests the need to incorporate bactericidal in addition to non-adhesive functions to protect competitive cell spreading over a long period.

Dumbbell-like hetero nanostructures based on gold and iron oxides is a promising material for biomedical applications, useful as versatile theranostic agents due the synergistic effect of their optical and magnetic properties. However, achieving precise control on their morphology, size dispersion, colloidal stability, biocompatibility and cell targeting remains as a current challenge. In this study, we address this challenge by employing biomimetic routes, using ferritin protein nanocages as template for these nanoparticles' synthesis. We present the development of an opto-magnetic nanostructures using the ferritin protein, wherein gold and iron oxide nanostructures were produced within its cavity. Initially, we investigated the synthesis of gold nanostructures within the protein, generating clusters and plasmonic nanoparticles. Subsequently, we optimized the conditions for the superparamagnetic nanoparticles synthesis through controlled iron oxidation, thereby enhancing the magnetic properties of the resulting system. Finally, we produce magnetic nanoparticles in the protein with gold clusters, achieving the coexistence of both nanostructures within a single protein molecule, a novel material unprecedented to date. We observed that factors such as temperature, metal/protein ratios, pH, dialysis, and purification processes all have an impact on protein recovery, loading efficiency, morphology, and nanoparticle size. Our findings highlight the development of ferritin-based nanomaterials as versatile platforms for potential biomedical use as multifunctional theranostic agents.

Healing wounds presents a significant challenge due to bacterial biofilm infections and the inherent drug resistance of these biofilms. This report introduces a multifunctional nanoplatform (NPs) designed to combat wound biofilm infections using NIR-II photothermal therapy. The NPs are self-assembled from amphiphilic polymers (AP) to encapsulate photothermal polymers (PT) through classic electrostatic interactions. Importantly, these NPs are electrically neutral, which enhances their ability to penetrate biofilms effectively. Once inside the biofilm, the NPs achieve complete thermal ablation of the biofilm under NIR-II laser irradiation. Additionally, when exposed to laser and the GSH microenvironment, the NPs exhibit strong photothermal effects and self-degradation capabilities. In vitro tests confirm that the NPs have excellent antibacterial and anti-biofilm properties against methicillin-resistant Staphylococcus aureus (MRSA). In vivo studies demonstrate that the NPs can efficiently clear wound biofilm infections and promote wound healing. Notably, the NPs show superior photothermal effects under NIR-II laser irradiation compared to NIR-I lasers. In summary, the developed NPs serve as an integrated diagnostic and therapeutic nano-antimicrobial agent, offering promising applications for biofilm wound infections and wound healing.

Skull base defects are a common complication after transsphenoidal endoscopic surgery, and their commonly used autologous tissue repair has limited clinical outcomes. Tissue-engineered scaffolds prepared by advanced techniques of electrostatic spinning and three-dimensional (3D) printing was an effective way to solve this problem. In this study, soft tissue scaffolds consisting of centripetal nanofiber mats and 3D-printed hard tissue scaffolds consisting of porous structures were prepared, respectively. And the two layers were combined to obtain bilayer composite scaffolds. The physicochemical characterization proved that the nanofiber mat prepared by polylactide-polycaprolactone (PLCL) electrospinning had a uniform centripetal nanofiber structure, and the loaded bFGF growth factor could achieve a slow release for 14 days and exert its bioactivity to promote the proliferation of fibroblasts. The porous scaffolds prepared with polycaprolactone (PCL), and hydroxyapatite (HA) 3D printing have a 300 μm macroporous structure with good biocompatibility. In vivo experiments results demonstrated that the bilayer composite scaffold could promote soft tissue repair of the skull base membrane through the centripetal nanofiber structure and slow-release of bFGF factor. It also played the role of promoting the regeneration of the skull base bone tissue. In addition, the centripetal nanofiber structure also had a promotional effect on the regeneration of skull base bone tissue.

Intraocular lens (IOL) implantation surgery is the most effective treatment for cataract. However, glistening formed by the incoming liquid microvacuoles can significantly damage postoperative visual quality after prolonged implantation, for which there is still lack of effective clinical treatment. In this study, inspired by the amazing water-repellency of natural superhydrophobic surface, a functionalized IOL material modified with the superhydrophobic and transparent coating was prepared using layer-by-layer electrostatic self-assembly technique combined with fluorination. After the alternate deposition of multiple cationic/anionic polyelectrolytes and silica nanoparticles of varying sizes on IOL materials, the constructed multilayered films with special surface roughness were further fluorinated to reduce surface energy. In addition to its excellent superhydrophobicity and transparency, this multilayered coating could efficiently eliminate the glistening formation of IOL under accelerated condition in vitro. Furthermore, the in vitro experiments with water droplets, cells, and bacteria suggested the superior antiadhesion property of such coating modified materials. The biocompatibility evaluation, both in vitro and in vivo, demonstrated the great biocompatibility of the materials modified with superhydrophobic and transparent coating. Therefore, this multilayered coating with excellent superhydrophobic and transparent characteristics can provide an available approach aiming at anti-glistening and antiadhesion of IOL materials. Advances in the fabrication process of surface coating with specific functions will enhance the practical application and clinical success of modified IOLs.

Inflammation and bacterial infection are important causes of implant failure, and the development of multifunctional titanium surfaces to address these issues is an effective means of treating infected bone defects. In this study, polyphenols (EGCG) and Zn²⁺ were first loaded onto the titanium surface to construct an EGCG/Zn²⁺ polyphenol metal network coating. Then melatonin (MT) was loaded into the EGCG/Zn²⁺ network structure to prepare the EGCG/Zn²⁺/MT composite coating. The results proved that the EGCG/Zn²⁺/MT coating had good mechanical properties, hydrophilicity, corrosion resistance and bioactivity. In vitro, the inhibition rates of EGCG/Zn²⁺/MT against E. coli and S. aureus were about 97 % and 81 %, respectively. In vitro experiments revealed that EGCG/Zn²⁺/MT could regulate the polarization of macrophages (RAW264.7) to M2 type, could induce vascularization of human umbilical vein endothelial cells (HUVEC), and could promote the differentiation of pro-osteoblasts (MC3T3-E1) to osteogenesis. Meanwhile, EGCG/Zn²⁺/MT achieved effective ROS scavenging within HUVEC and MC3T3-E1. In vivo experiments demonstrated that the EGCG/Zn²⁺/MT coatings possessed favorable biosafety, anti-inflammatory, antimicrobial, and bone repair capabilities. This study provides a simple and versatile strategy for designing multifunctional surfaces with both antimicrobial, anti-inflammatory, antioxidant, angiogenic and osteogenic properties.