Cartilage structure-inspired nanofiber-hydrogel composite with robust proliferation and stable chondral lineage-specific differentiation function to orchestrate cartilage regeneration for artificial tracheal construction.

Tissue engineering strategies hold promise for constructing biomimetic tracheal substitutes to repair circumferential tracheal defects. However, current strategies for constructing off-the-shelf cartilage analogs for artificial trachea grafts face challenges of chondrocyte scarcity and inadequate culture strategies, which require extensive cell expansion and prolonged culture to generate robust neo-cartilage. To address these issues, we developed a nanofiber-hydrogel composite with superior mechanical performance by incorporating fragment oxidized bacterial cellulose (BC) nanofibers into a gelatin methacryloyl (GelMA) hydrogel network.

A multifunctional bacterial cellulose-based dressing modified by quaternized chitosan and grafted protocatechuic acid for diabetic ulcer.

Herein, we developed a multifunctional bacterial cellulose-based dressing (PHBC) modified by quaternized chitosan (HACC) along with protocatechuic acid (PA), through in situ biosynthesis combined with covalent immobilization. The obtained PHBC dressing maintained the excellent physicochemical characteristics of BC, such as high porosity (above 76 %); high water absorption ratio, >80 % of water absorption rate (approximately 30 g/g) has completed in half an hour; favorable hydrophilicity with contact angle of about 50° and excellent flexibility. The introduction of PA-grafted HACC endows exhibited outstanding antibacterial properties against, anti-inflammatory performance and antioxidant capacity.

Targeting Bacteria-Induced Ferroptosis of Bone Marrow Mesenchymal Stem Cells to Promote the Repair of Infected Bone Defects.

The specific mechanisms underlying bacteria-triggered cell death and osteogenic dysfunction in host bone marrow mesenchymal stem cells (BMSCs) remain unclear, posing a significant challenge to the repair of infected bone defects. This study identifies ferroptosis as the predominant cause of BMSCs death in the infected bone microenvironment. Mechanistically, the bacteria-induced activation of the innate immune response in BMSCs leads to upregulation and phosphorylation of interferon regulatory factor 7 (IRF7), thus facilitating IRF7-dependent ferroptosis of BMSCs through the transcriptional upregulation of acyl-coenzyme A synthetase long-chain family member 4 (ACSL4).

Microarray analysis of tRNA-derived small RNA (tsRNA) in LPS-challenged macrophages treated with metformin.

Metformin, a widely used anti-diabetic drug, has demonstrated its efficacy in addressing various inflammatory conditions. tRNA-derived small RNA (tsRNA), a novel type of small non-coding RNA, exhibits diverse regulatory functions and holds promise as both a diagnostic biomarker and a therapeutic target for various diseases. The purpose of this study is to investigate whether the abundance of tsRNAs changed in LPS versus LPS + metformin-treated cells, utilizing microarray technology.

The Role and Mechanism of Metformin in Inflammatory Diseases.

Metformin is a classical drug used to treat type 2 diabetes. With the development of research on metformin, it has been found that metformin also has several advantages aside from its hypoglycemic effect, such as anti-inflammatory, anti-aging, anti-cancer, improving intestinal flora, and other effects. The prevention of inflammation is critical because chronic inflammation is associated with numerous diseases of considerable public health.

Iodine-Doped 3D Print Ti Alloy for Antibacterial Therapy on Orthopedic Implants.

This study presents a novel approach to mitigating bacterial infections and antibiotic resistance in medical implants through the integration of iodine-doping and 3D printing techniques. Iodine, with its potent antibacterial properties, and titanium alloy (Ti), a popular metal for implants due to its mechanical and biological properties, were combined via electrodeposition on 3D-printed titanium alloy (3D-Ti) implants. Scanning electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy confirmed the successful creation of iodine-doped titanium implants with improved iodine content due to the rough surface of the 3D-printed material.

Homogeneous silver nanoparticle loaded polydopamine/polyethyleneimine-coated bacterial cellulose nanofibers for wound dressing.

Utilizing mussel-inspired chemistry is an advanced strategy for surface modification, because dopamine (DA) can form a material-independent adhesive coating and further functionalization can be achieved, including the production of silver nanoparticles (AgNPs). Nevertheless, DA easily aggregates in the nanofiber network structure of bacterial cellulose (BC), which not only blocks the pores in the BC structure but also leads to the formation of large silver particles and the burst release of highly cytotoxic silver ions. Herein, a homogeneous AgNP-loaded polydopamine (PDA)/polyethyleneimine (PEI) coated BC was constructed via a Michael reaction between PDA and PEI.

A dual functional Ti-Ga alloy: inhibiting biofilm formation and osteoclastogenesis differentiation via disturbing iron metabolism.

Background: Although biomedical implants have been widely used in orthopedic treatments, two major clinical challenges remain to be solved, one is the bacterial infection resulting in biofilm formation, and the other is aseptic loosening during implantation due to over-activated osteoclastogenesis. These factors can cause many clinical issues and even lead to implant failure. Thus, it is necessary to endow implants with antibiofilm and aseptic loosening-prevention properties, to facilitate the integration between implants and bone tissues for successful implantation.

Metformin Improves Burn Wound Healing by Modulating Microenvironmental Fibroblasts and Macrophages.

Metformin, a biguanide, exerts different functions through various signaling pathways. In order to investigate the function and mechanism of metformin in burn wounds, we established burn rat models, subcutaneously injected metformin to treat the wounds, and observed the morphologies and the expression of collagen I, collagen III, fibronectin, and pro-inflammatory markers. In vitro experiments were performed to investigate the effects of metformin on the proliferation, migration, and collagen I synthesis of the mouse embryonic fibroblast (NIH 3T3) cell line and on the proliferation, apoptosis, and immune response of the mouse mononuclear macrophage (RAW 264.

Smart-Temporary-Film-Based Local-Delivery System with Controllable Drug-Release Behavior.

The development of a simple local drug-delivery system that exhibits the advantages of macro- and microscale carriers with controllable drug-release behavior is still highly desired. Herein, in this work, a smart temporary film was prepared from doxorubicin (DOX)-loaded shape-memory microgels via a simple hot-compression programming method. The temporary film showed a very smooth surface and easy handing, as well as macroscopy mechanical properties, which could disintegrate into the microgels with heating at 45 °C.

Fabrication of gentamicin loaded Col-I/HA multilayers modified titanium coatings for prevention of implant infection.

In this study, gentamicin loaded collagen I/hyaluronic acid multilayers modified titanium coating (TC-AA(C/H)-G) was fabricated a layer-by-layer (LBL) covalent immobilization method. The drug releasing properties of collagen I/Hyaluronic acid (Col-I/HA) multilayers and the effect of loaded gentamicin on the antibacterial properties and cytocompatibility of modified TC were investigated. The gentamicin release assay indicated that the Col-I/HA multilayers modified TC exhibited agreeable drug-loading amount (537.

Designment of polydopamine/bacterial cellulose incorporating copper (II) sulfate as an antibacterial wound dressing.

Improving antibacterial performance is one of the prerequisites for the clinical application of bacterial cellulose (BC)-based dressings. In this study, a novel copper (Cu) ion loaded BC-based antibacterial wound dressing was prepared via codeposition of polydopamine (PDA) and copper ion. The scanning electron microscope (SEM) results showed that the copper ion/PDA coating was more uniform than the PDA coating, and the 3D nanopore structure of BC was retained in Cu@PBC.

De novo strategy with engineering a multifunctional bacterial cellulose-based dressing for rapid healing of infected wounds.

The treatment and healing of infected skin lesions is one of the major challenges in surgery. To solve this problem, collagen I (Col-I) and the antibacterial agent hydroxypropyltrimethyl ammonium chloride chitosan (HACC) were composited into the bacterial cellulose (BC) three-dimensional network structure by a novel membrane-liquid interface (MLI) culture, and a Col-I/HACC/BC (CHBC) multifunctional dressing was designed. The water absorption rate and water vapor transmission rate of the obtained CHBC dressing were 35.

Rational Design of All-Organic Nanoplatform for Highly Efficient MR/NIR-II Imaging-Guided Cancer Phototheranostics.

Organic theranostic nanomedicine has precision multimodel imaging capability and concurrent therapeutics under noninvasive imaging guidance. However, the rational design of desirable multifunctional organic theranostics for cancer remains challenging. Rational engineering of organic semiconducting nanomaterials has revealed great potential for cancer theranostics largely owing to their intrinsic diversified biophotonics, easy fabrication of multimodel imaging platform, and desirable biocompatibility.

Engineering a novel antibacterial agent with multifunction: Protocatechuic acid-grafted-quaternized chitosan.

As a mild cationic antibacterial agent, hydroxypropyltrimethyl ammonium chloride chitosan (HACC) could kill gram-positive bacteria and gram-positive drug-resistant bacteria without cytotoxicity. Nevertheless, it was not effective against gram-negative bacteria. Herein, protocatechuic acid (PA) with broad-spectrum antibacterial properties and pharmacological activities was grafted on HACC.

Optimized Nanointerface Engineering of Micro/Nanostructured Titanium Implants to Enhance Cell-Nanotopography Interactions and Osseointegration.

The success of orthopedic implants requires rapid and complete osseointegration which relies on an implant surface with optimal features. To enhance cellular function in response to the implant surface, micro- and nanoscale topography have been suggested as essential. The aim of this study was to identify an optimized Ti nanostructure and to introduce it onto a titanium plasma-sprayed titanium implant (denoted NTPS-Ti) to confer enhanced immunomodulatory properties for optimal osseointegration.

Improved antibacterial properties of collagen I/hyaluronic acid/quaternized chitosan multilayer modified titanium coatings with both contact-killing and release-killing functions.

Implant infection is one of the most severe complications after orthopedic surgery. The construction of an antibacterial coating on orthopedic implants with release-killing or contact-killing is one of the most efficient strategies to prevent implant-related infections. Here we reported a hydroxypropyltrimethyl ammonium chloride chitosan (HACC) based multilayer modified plasma-sprayed porous titanium coating generated via the layer-by-layer covalent-immobilized method.

Interpenetrated nano- and submicro-fibrous biomimetic scaffolds towards enhanced mechanical and biological performances.

Developing fibrous scaffolds with hierarchical structures that closely mimic natural extracellular matrix (ECM) is highly desirable. However, fabricating scaffolds with true nanofibers (<100 nm) and submicrofibers (<1 μm) remains a big challenge. In this work, to mimic the fibrillar structure of natural ECM, bacterial cellulose (BC) nanofibers were hybridized with cellulose acetate (CA) submicrofibers for the first time.

Studies on bacterial cellulose/poly(vinyl alcohol) hydrogel composites as tissue-engineered corneal stroma.

Corneal transplantation is currently the major solution in the treatment of severe corneal diseases. However, it is restricted due to the limited number of corneal donors. A tissue-engineered cornea is a potential substitute which could help overcome this limitation.

An in vivo study on the effect of coating stability on osteointegration performance of collagen/hyaluronic acid multilayer modified titanium implants.

Aseptic loosening of implant is one of the main causes of Ti-based implant failure. In our previous work, a novel stable collagen/hyaluronic acid (Col/HA) multilayer modified titanium coatings (TCs) was developed by layer-by-layer (LBL) covalent immobilization technique, which showed enhanced biological properties compared with TCs that were physically absorbed with Col/HA multilayer . In this study, a rabbit model with femur condyle defect was employed to compare the osteointegration performance of them.

Preparation, structural characterization, and in vitro cell studies of three-dimensional SiO-CaO binary glass scaffolds built ofultra-small nanofibers.

Three-dimensional (3D) nanofibrous scaffolds hold great promises in tissue engineering and regenerative medicine. In this work, for the first time, 3D SiO-CaO binary glass nanofibrous scaffolds have been fabricated via a combined method of template-assisted sol-gel and calcination by using bacterial cellulose as the template. SEM with EDS, TEM, and AFM confirm that the molar ratio of Ca to Si and fiber diameter of the resultant SiO-CaO nanofibers can be controlled by immersion time in the solution of tetraethyl orthosilicate and ethanol.

Immobilizing bacitracin on titanium for prophylaxis of infections and for improving osteoinductivity: An in vivo study.

Bacitracin immobilized on the titanium (Ti) surface significantly improves anti-bacterial activity and biocompatibility in vitro. In the current study, we investigated the biologic performance (bactericidal effect and bone-implant integration) of bacitracin-modified Ti in vivo. A rat osteomyelitis model with femoral medullary cavity placement of Ti rods was employed to analyze the prophylactic effect of bacitracin-modified Ti (Ti-BC).