Biomaterials Science最新文献

Malignant fungating wounds (MFWs) are cancer-related complications that arise from metastases in advanced cancers. They appear in 5-14% of cancer patients, with higher prevalence in breast (66%) and head and neck (24%) cancers. Novel therapeutic routes for the management of MFWs rely on plant-based treatments, e.g. oxymatrine (OXM), an alkaloid derived from a Chinese plant with anticancer and anti-inflammatory properties. The objective of this work was to assess the potential of polyvinyl alcohol/casein (PVA/CAS) hydrogels to be used as dressings for OXM delivery. CAS can stimulate the immune system, while PVA is one of the most used synthetic polymers in the composition of hydrogels for medical applications. Six different hydrogel formulations were prepared following different procedures: freeze-thawing (FT) and cast drying (CD) for 24 or 48 h, with and without the addition of genipin (GE), a crosslinking agent. The hydrogels were loaded with OXM, and their release behaviour was studied. PVA/CAS-24CD + GE showed the best release profile. After being subjected to sterilisation by high hydrostatic pressure, it was further investigated in terms of physicochemical properties, mechanical characteristics and biocompatibility. Overall, this hydrogel revealed adequate characteristics to be used as a biocompatible medicated dressing for OXM release.

Signs of bacterial activities have been reported in a variety of disease models. Here, we extracted plant cytoderm ghosts (PCGs) from plant cells, acting as bacteria-responsive drug delivery systems (DDSs) that release drugs specifically in response to the presence or activity of bacteria. Cellulose, which is one of the main components of PCGs, can be degraded in the presence of specialized bacteria that secrete enzymes to convert the cellulose into simpler sugars, thus breaking down the structure of PCGs to release the loaded drugs. In our study, PCGs loaded with ciprofloxacin (PCG@CIP) could effectively inhibit the proliferation and retention of bacteria at the infection site, and improve the local wound microenvironment to accelerate wound repair. In addition, the PCG platform with anticancer drugs could effectively regulate the progression of tumor growth. Therefore, we report a new drug delivery system that responds to the microbiota based on plant cytoderm, providing a new option for drug responsive delivery.

The development of bioink-based 3D-printed scaffolds has revolutionized bone tissue engineering (BTE) by enabling patient-specific and biomimetic constructs for bone regeneration. This review focuses on the biocompatibility and mechanical properties essential for scaffold performance, highlighting advancements in bioink formulations, material combinations, and printing techniques. The key biomaterials, including natural polymers (gelatin, collagen, alginate), synthetic polymers (polycaprolactone, polyethylene glycol), and bioactive ceramics (hydroxyapatite, calcium phosphate), are discussed concerning their osteoconductivity, printability, and structural integrity. Despite significant progress, challenges remain in achieving optimal mechanical strength, degradation rates, and cellular interactions. The review explores emerging strategies such as gene-activated bioinks, nanocomposite reinforcements, and crosslinking techniques to enhance scaffold durability and bioactivity. By synthesizing recent developments, this work provides insights into future directions for bioink-based scaffolds, paving the way for more effective and personalized bone regenerative therapies.

While increased intracellular calcium (Ca²⁺) has been identified as a key effect of nanoparticles on endothelial cells, the mechanism has not been fully elucidated or examined under shear stress. Here, we show the effect of several types of 20 nm particles on Ca²⁺ in the presence of shear stress in human umbilical vein endothelial cells (HUVECs), human coronary artery endothelial cells (HCAECs), and human cardiac microvascular endothelial cells (HMVEC-Cs). Intracellular Ca²⁺ levels increased by nearly three-fold in these cell types upon exposure to 100 μg mL^-1 20 nm Au particles, which was not seen in response to larger or smaller particles. An antagonist to the calcium channel - transient receptor potential vanilloid-type 4 (TRPV4) - drastically reduced the amount of calcium by 9.3-fold in HUVECs exposed to 0.6 Pa shear stress and 100 μg mL^-1 20 nm gold particles, a trend upheld in both HCAECs and HMVEC-Cs. Cell alignment in the direction of fluid flow is a well-known phenomenon in endothelial cells, and interestingly, cells in the presence of 20 nm particles with fluid flow had a higher alignment index than cells in the fluid flow alone. When compared with previous works, these results indicated that 20 nm particles may be inducing endothelial permeability by activating the TRPV4 channel in vitro. The potential of nanoparticle delivery technologies hinges on an improved understanding of this effect toward improved delivery with limited toxicity.

Ferrous iron (Fe²⁺)-based chemodynamic therapy (CDT) shows great potential for improving chemotherapeutic efficacy and reducing side effects. However, spontaneous oxidation and biological matrixes can influence the catalytic reactive oxygen species (ROS) generation of Fe²⁺, thereby limiting the efficacy of CDT. Herein, we reported a simple and convenient method to construct hyaluronic acid (HA)-stabilized iron/zinc oxide nanoparticles (IZ@H NPs), which showed intrinsic peroxidase (POD)-like activity and excellent light-activated Fe²⁺ release performance. Moreover, we demonstrate that catalytic ROS generation follows a cascade amplification manner due to the light-activated release of Fe²⁺ from IZ@H NPs, leading to formation of iron-DNA complexes (IDCs). After loading doxorubicin (DOX), the nanosystem (termed IZD@H NPs) exhibits tumor cell targeting, robust ROS generation and high cytotoxicity, significantly suppressing tumor growth in xenograft mouse models while maintaining good biosafety. This work gives novel insight into amplifying Fe²⁺-mediated catalytic ROS generation and presents a new strategy for in vivo Fe²⁺ delivery to enhance chemodynamic/chemotherapy.

Inflammation is a carefully orchestrated response of the immune system to repair injured tissues and clear various damage factors. However, dysregulated inflammation can eventually contribute to the development and progression of various inflammatory diseases. Although anti-inflammatory drugs have demonstrated certain therapeutic efficacy in clinical settings, significant limitations still persist, highlighting the necessity for the development of improved approaches to address complex inflammatory conditions. Micro/nanomotors (MNMs) have shown significant promise for applications in the biomedical field due to their micro/nano-scale sizes and autonomous movement. Unlike traditional nanoparticles, which exhibit passive diffusion in biological fluids, MNMs can convert external energy into a driving force for self-propulsion. This capability not only enhances the tissue penetration depth and retention rates but also facilitates interaction with inflammatory lesions. Recent efforts have suggested that MNMs for inflammatory disease therapy could provide an efficient therapeutic effect. Herein, we mainly introduce the recent advances in inflammatory disease therapy based on MNMs. We conclude by discussing both the obstacles and potential opportunities for MNMs innovations in addressing inflammation.

We performed inverse synthesis to create 1152 structural analogs of polymyxin B with modified hydrophilicity and charge properties using OBOC technology. This led to the identification of two promising candidates that provided insights into structure-activity relationships. These compounds maintained high antibacterial activity while expanding the safety window 4-16 times.

Small interfering RNA (siRNA) is a potent method for silencing survivin mRNA within cells, offering a promising option for treating hepatocellular carcinoma (HCC) since survivin is specifically overexpressed in HCC cells. However, the clinical use of gene therapy with siRNA is limited by factors such as rapid enzyme degradation, low cell uptake, and non-specific distribution in the body. In this study, we investigate the use of a specially selected metal-organic framework (MOF) to encapsulate siRNA, with the aim of silencing survivin mRNA in HCC cells and reducing the survivin protein level. The MOF was functionalized with triantennary N-acetylgalactosamine (GalNAc), which has high affinity for asialoglycoprotein receptors that are overexpressed in HCC cells. Both in vitro and in vivo experiments showed that the GalNAc-decorated MOF specifically accumulated in HCC tumor tissue and was effectively endocytosed by HCC cells. The protective properties of the MOF increased the stability of siRNA and allowed for significant downregulation of survivin expression in HCC tumors, contributing to tumor inhibition through the suppression of cell proliferation and the induction of apoptosis. These findings highlight the potential of MOF-based siRNA delivery systems for targeted cancer therapy.

Polyurethane (PU) is a synthetic polymer with a micro-phase separation structure and tunable mechanical properties. Since the first successful application of thermoplastic polyurethane (TPU) in vivo in 1967, PU has become an important biomedical material for various applications in tissue engineering, artificial organs, wound healing, surgical sutures, medical catheters, and bio-flexible electronics. This review summarizes three strategies for regulating the mechanical properties of medical PU elastomers, including monomer design and selection, modification and arrangement of segments, and incorporation of nanofillers. Furthermore, we discuss the feasible strategies to achieve the biodegradability and self-healing properties of polyurethane to meet specific biomedical needs. Finally, this review highlights the latest advancements in functionalized PU for biomedical applications and offers insights into its future development.

Bacterial nanocellulose (BNC) is a versatile natural polymer with unique morphological properties. However, its susceptibility to biofouling limits its utility in healthcare. To address this challenge, this study explores the incorporation of gallic acid, a phenolic acid with potent antimicrobial and antithrombotic properties, into BNC membranes. Additionally, a novel drying method termed gradual freezing is introduced, resulting in a directionally-aligned BNC membrane with enhanced mechanical integrity and high porosity. Using glycerol as a solvent and plasticizer, gallic acid was loaded into air-dried BNC (AD-BNC), freeze-dried BNC (FD-BNC), and gradually-frozen BNC (GF-BNC) membranes. Successful drug-loading into FD-BNC and GF-BNC significantly increased the elasticity of the films, however mechanical testing indicated that GF-BNC and its gallic acid/glycerol loaded counterpart (GF-GG-BNC) achieved overall optimal mechanical strength and elasticity. These samples were selected for further antifouling testing. Antibacterial assays demonstrated the practical efficacy of GF-GG-BNC in inhibiting the proliferation and biofilm formation of E. coli and S. aureus, while favorable antithrombotic behaviour prevented clot formation and red blood cell adhesion on the material's surface when compared to GF-BNC membranes. These findings highlight the potential of GF-GG-BNC as a multifunctional biomaterial for the prevention of biofouling in biomedical applications.