Biomaterials Science最新文献

The tumor microenvironment (TME) is characterized by a complex array of factors, including aerobic conditions, high glutathione (GSH) levels, acidic pH, and elevated hydrogen peroxide (H₂O₂) content, all of which promote cancer progression and contribute to poor prognosis. Fortunately, these challenges can be addressed using MnO₂-based nanomaterials. In this study, we have designed and synthesized a Curcumin/MnO₂@PLGA@4T1 cell membrane (CMP@4T1m) system aimed at remodelling the TME and enhancing sonodynamic immunotherapy for breast cancer. Through the homologous targeting ability of 4T1m, CMP@4T1m efficiently accumulates at the tumor site. Upon ultrasound irradiation, curcumin (Cur) acts as a sonosensitizer, generating cytotoxic reactive oxygen species (ROS) that induce immunogenic cell death (ICD), activate T-cell responses, and repolarize protumoral M2-like macrophages to antitumoral M1-like macrophages. In the TME, which is mildly acidic and enriched with GSH and H₂O₂, MnO₂ not only oxidizes GSH to glutathione disulfide (GSSG) but also reacts with H₂O₂ and H⁺ to produce oxygen, alleviating hypoxia and significantly enhancing the sonodynamic immunotherapy effect. Additionally, Mn²⁺ generated during this process converts H₂O₂ into cytotoxic hydroxyl radicals (˙OH). This study thus lays the foundation for advancing cancer nanomedicine, offering a novel approach that integrates TME remodelling with sonodynamic immunotherapy.

Early diagnosis of brain tumors is challenging due to their complexity and delicate structure. Conventional imaging techniques like MRI, CT, and PET are unable to provide detailed visualization of early-stage brain tumors. Early-stage detection of brain tumors is vital for enhancing patient outcomes and survival rates. So far, several scientists have dedicated their efforts to innovating advanced diagnostic probes to efficiently cross the BBB and selectively target brain tumors for optimal imaging. The integration of these techniques presents a viable pathway for non-invasive, accurate, and early-stage tumor identification. Herein, we provide a timely update on the various imaging probes and potential challenges for the diagnosis of early-stage brain tumors. Furthermore, this review highlights the significance of integrating advanced imaging probes for improving the early detection of brain tumors, ultimately enhancing treatment outcomes. Hopefully, this review will stimulate the interest of researchers to accelerate the development of new imaging probes and even their clinical translation for improving the early diagnosis of brain tumors.

Immune checkpoint inhibitors (ICIs) have demonstrated remarkable success in treating various types of solid tumors; however, only a limited number of patients currently benefit from these therapeutic agents. Developing novel ICIs that elicit systemic and durable antitumor immune responses remains a significant challenge in improving immunotherapy outcomes. In this study, we engineered PD-1/LAG-3 receptors onto cell membrane nanovesicles to simultaneously block two immune checkpoints for the treatment of colorectal cancer. This dual-checkpoint blockade strategy led to significantly more potent tumor growth suppression in mice with MC38 xenografts compared to nanovesicles targeting PD-1 or LAG-3 alone. Notably, the hybrid nanovesicles substantially rejuvenated exhausted CD8⁺ T cells, promoting dendritic cell maturation and depleting regulatory T cells (Tregs). This research highlights the promising potential of cell membrane nanovesicles as an effective platform for delivering multiple immune checkpoints in cancer immunotherapy, offering a novel strategy to enhance therapeutic efficacy.

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.