Journal of Materials Chemistry B最新文献

For decades, implant-associated infections (IAIs) caused by pathogenic bacteria have been associated with high failure and mortality rates in implantation surgeries, posing a serious threat to global public health. Therefore, developing a functionalized biomaterial coating with anti-fouling and anti-bacterial functions is crucial for alleviating implant infections. Herein, a near-infrared-responsive anti-bacterial and anti-adhesive coating (Ti-PEG-Cu_2−xS) constructed on the surface of titanium (Ti) implants is reported. This coating is composed of nano-Cu_2−xS with anti-bacterial activity and super-hydrophilic polyethylene glycol (PEG). Under near-infrared irradiation, the nano-catalyst Cu_2−xS on the surface of Ti-PEG-Cu_2−xS induces bacterial death by catalyzing the production of singlet oxygen (¹O₂). The Ti-PEG-Cu_2−xS coating can effectively prevent bacterial adhesion and biofilm formation. This coating combines the antibacterial mechanisms of “active attack” and “passive defense”, which can kill bacteria and inhibit biofilm formation. The results of in vitro and in vivo experiments have shown that Ti-PEG-Cu_2−xS exhibits excellent anti-bacterial properties under near-infrared irradiation and can effectively prevent implant-related infections caused by Escherichia coli (E. coli) ATCC 8739 and Staphylococcus aureus (S. aureus). The antibacterial efficiency of Ti-PEG-Cu_2−xS coatings against E. coli was 99.96% ± 0.058% and that of S. aureus was 99.66% ± 0.26%, respectively. In addition, the Ti-PEG-Cu_2−xS coating has good blood compatibility and excellent bactericidal ability. Therefore, this multifunctional coating combines a non-adhesive surface strategy and a near-infrared phototherapy sterilization method, effectively blocking the initial attachment and proliferation of bacteria on implants via photothermal/photodynamic effects and providing a promising method for preventing bacterium-induced IAIs.

Tissue damage and cell death occurring during photothermal therapy (PTT) for tumors can induce an inflammatory response that is detrimental to tumor therapy. Herein, ultrathin Mo metallene nanosheets with a thickness of <5 nm prepared by liquid phase exfoliation were explored as functional hyperthermia agents for non-inflammatory ablation of tumors. The obtained Mo metallene nanosheets exhibited good photothermal conversion properties and significant reactive oxygen species (ROS) scavenging ability, thus achieving superior cancer cell ablation and anti-inflammatory effects in vitro. For in vivo experiments, 4T1 tumors were ablated while the inflammation-related cytokine levels did not obviously increase, demonstrating that the inflammatory response induced by PTT was inhibited by the anti-inflammatory properties of Mo metallene nanosheets. Moreover, Mo metallene nanosheets depicted good dispersibility and biocompatibility, beneficial for biomedical applications. This work introduces Mo metallenes as promising hyperthermia agents for non-inflammatory PTT of tumors.

Lipid nanoparticles (LNPs) are commonly employed for drug delivery owing to their considerable drug-loading capacity, low toxicity, and excellent biocompatibility. Nevertheless, the formation of protein corona (PC) on their surfaces significantly influences the drug's in vivo fate (such as absorption, distribution, metabolism, and elimination) upon administration. PC denotes the phenomenon wherein one or multiple strata of proteins adhere to the external interface of nanoparticles (NPs) or microparticles within the biological milieu, encompassing ex vivo fluids (e.g., serum-containing culture media) and in vivo fluids (such as blood and tissue fluids). Hence, it is essential to claim the PC formation behaviors and mechanisms on the surface of LNPs. This overview provided a comprehensive examination of crucial aspects related to such issues, encompassing time evolution, controllability, and their subsequent impacts on LNPs. Classical studies of PC generation on the surface of LNPs were additionally integrated, and its decisive role in shaping the in vivo fate of LNPs was explored. The mechanisms underlying PC formation, including the adsorption theory and alteration theory, were introduced to delve into the formation process. Subsequently, the existing experimental outcomes were synthesized to offer insights into the research and application facets of PC, and it was concluded that the manipulation of PC held substantial promise in the realm of targeted delivery.

Abnormal neuronal polarity leads to early deficits in Alzheimer's disease (AD) by affecting the function of axons. Precise and rapid evaluation of polarity changes is very important for the early prevention and diagnosis of AD. However, due to the limitations of existing detection methods, the mechanism related to how neuronal polarity changes in AD is unclear. Herein, we reported a ratiometric fluorescent probe characterized by neutral molecule to disclose the polarity changes in nerve cells and the brain of APP/PS1 mice. Cy7-K showed a sensitive and selective ratiometric fluorescence response to polarity. Remarkably, unlike conventional intramolecular charge transfer fluorescent probes, the fluorescence quantum yield of Cy7-K in highly polar solvents is higher than that in low polar solvents due to the transition of neutral quinones to aromatic zwitterions. Using the ratiometric fluorescence imaging, we found that beta-amyloid protein (Aβ) inhibits the expression of histone deacetylase 6, thereby increasing the amount of acetylated Tau protein (AC-Tau) and ultimately enhancing cell polarity. There was a high correlation between polarity and AC-Tau. Furthermore, Cy7-K penetrated the blood–brain barrier to image the polarity of different brain regions and confirmed that APP/PS1 mice had higher polarity than Wild-type mice. The probe Cy7-K will be a promising tool for assessing the progression of AD development by monitoring polarity.

Cancer immunotherapy, as an emerging approach to cancer treatment, has tremendous potential for application. Compared to traditional methods such as surgery, chemotherapy, and radiation therapy, it has the ability to restore the patient's immune system, leading to long-term immune memory with less damage to normal tissues. However, immunotherapy has its limitations, including limited therapeutic efficacy, restricted patient populations, and inconsistent treatment responses. Finding effective immunotherapeutic approaches has become a key focus of its clinical application. The adenosine pathway is a recently discovered tumor immune regulatory signaling pathway. It can influence the metabolism and growth of tumor cells by acting through key enzymes in the adenosine pathway, thereby affecting the development of tumors. Therefore, inhibiting the adenosine pathway is an effective cancer immunotherapy. Common adenosine pathway inhibitors include small molecules and antibody proteins, and extensive preclinical trials have demonstrated their effectiveness in inhibiting tumor growth. The short half-life, low bioavailability, and single administration route of adenosine pathway inhibitors limit their clinical application. With the advent of nanotechnology, nano-delivery of adenosine pathway inhibitors has addressed these issues. Compared to traditional drugs, nano-drugs extend the drug's circulation time and improve its distribution within the body. They also offer targeting capabilities and have low toxic side effects, making them very promising for future applications. In this review, we discuss the mechanism of the adenosine pathway in tumor immune suppression, the clinical applications of adenosine pathway inhibitors, and nano-delivery based on adenosine pathway inhibitors. In the final part of this article, we also briefly discuss the technical issues and challenges currently present in nano-delivery of adenosine pathway inhibitors, with the hope of advancing the progress of adenosine inhibitor nano-drugs in clinical treatment.

Gallic acid (GA), derived from land plants, possesses diverse physiological benefits, including anti-inflammatory and anticancer effects, making it valuable for biomedical applications. In this study, GA was used to modify the surface of dendritic mesoporous silica nanoparticles (DMSNs) via carbamate (DMSN-NCO-GA) or amide (DMSN-NH-GA) bonds, using a post-grafting technique. To explore GA-conjugated materials' potential in modulating cancer cell redox status, three variants of osteosarcoma cells (U2-OS) were used. These variants comprised the wild-type cells (NEO), the cells overexpressing the wild-type human Golgi anti-apoptotic protein (hGAAP), and the null mutant of hGAAP (Ct-mut), as this protein was previously demonstrated to play a role in intracellular reactive oxygen species (ROS) accumulation and cell migration. In the absence of external ROS triggers, non-modified DMSNs increased intracellular ROS in Ct-mut and NEO cells, while GA-conjugated materials, particularly DMSN-NH-GA, significantly reduced ROS levels, especially pronounced with higher GA concentrations and notably in hGAAP cells with inherently higher ROS levels. Additionaly, NH-GA conjugates were less cytotoxic, more effective in reducing cell migration, and had higher ROS buffering capacity compared to DMSN-NCO-GA materials. However, in the presence of the external stressor tert-butyl-hydroperoxide (TBHP), NCO-GA conjugates showed more efficient reduction of intracellular ROS. These findings suggest that varying chemical decoration strategies of nanomaterials, along with the accessibility of functional groups to the cellular environment, significantly influence the biological response in osteosarcoma cells. Highlighting this, GA-conjugation is a promising method for implementing antioxidant properties and inhibiting cancer cell migration, warranting further research in anticancer treatment and drug development.

Gambogic acid (GA) as a naturally derived chemotherapeutic agent is of increasing interest for antitumor therapy. However, current research mainly focuses on improving the pharmacological properties to overcome the shortcomings in clinical applications or as a synergistic anticancer agent in combination with chemotherapy and chemophototherapy. Yet, the material properties of GA (e.g., self-assembly) are often neglected. Herein, we validated the self-assembly function of GA and its huge potential as a single-component active carrier for synergistic delivery using pyropheophorbide-a (PPa) as a drug model. The results showed that self-assembled GA drives the formation of nano-GA/PPa mainly through noncovalent interactions such as π–π stacking, hydrophobic interactions, and hydrogen bonding. Additionally, although no significant differences in cytotoxicity were found between the individual in vitro chemotherapy and combined chemophototherapy, the as-prepared nano-GA/PPa exhibits remarkably improved water solubility and multiple favorable therapeutic features, leading to a prominent in vivo photochemotherapy efficiency of 89.3% inhibition rate with reduced hepatotoxicity of GA. This work highlights the potential of self-assembled GA as a drug delivery carrier for synergistic biomedical applications.

In cardiac tissue engineering, myocardial surface patches and hydrogel intramyocardial injections represent the two primary hydrogel-based strategies for myocardial infarction (MI) treatment. However, the comparative effectiveness of these two treatments remains uncertain. Therefore, this study aimed to compare the effects of the two treatment modalities by designing a simple and reproducible hydrogel cross-linked with γ-PGA and 4-arm-PEG-SG. To improve mitochondrial damage in cardiomyocytes (CMs) during early MI, we incorporated the mitochondria-targeting antioxidant MitoQ into the hydrogel network. The hydrogel exhibited excellent biodegradability, biocompatibility, adhesion, and injectability in vitro. The hydrogel was utilized for rat MI treatment through both patch adhesion and intramyocardial injections. In vivo results demonstrated that the slow release of MitoQ peptide from the hydrogel hindered ROS production in CM, alleviated mitochondrial damage, and enhanced CM activity within 7 days, effectively inhibiting MI progression. Both hydrogel intramyocardial injections and patches exhibited positive therapeutic effects, with intramyocardial injections demonstrating superior efficacy in terms of cardiac function and structure in equivalent treatment cycles. In conclusion, we developed a MitoQ/hydrogel system that is easily prepared and can serve as both a myocardial patch and an intramyocardial injection for MI treatment, showing significant potential for clinical applications.

Diabetic foot ulcers are a significant complication affecting roughly 15% of diabetic patients. These chronic wounds can be incredibly burdensome, leading to high treatment costs, potential amputations, and additional health complications. Microbiological studies reveal that bacterial infections are the primary culprit behind delayed wound healing. To solve the problem of infection at the wound site, the most fundamental thing is to kill the pathogenic bacteria. Herein, a neoteric strategy to construct novel antibacterial hydrogel COA-T3 that combined photosensitizers (PSs) and antimicrobial peptides (AMPs) via covalent coupling was proposed. Hydrogel COA-T3 composed of quaternized chitosan (QCS) and oxidized dextran (OD) was constructed for co-delivery of the photosensitizer TPI-PN and the antimicrobial peptide HHC10. In vitro and in vivo experiments demonstrated remarkable effectiveness of COA-T3 against drug-resistant bacteria. Furthermore, the hydrogel significantly promoted healing of diabetic infected wounds. This enhanced antibacterial activity is attributed to the pH-sensitive release of both PSs and AMPs within the hydrogel. Additionally, COA-T3 exhibits excellent biocompatibility, making it a promising candidate for wound dressing materials. These findings indicated that the COA-T3 hydrogel is a promising wound dressing material for promoting the healing of diabetic foot ulcers by providing an environment conducive to improved wound healing in diabetic patients.

Rapid and sensitive detection of food-borne bacteria has remained challenging over the past few decades. We propose a surface-enhanced Raman scattering sensing strategy based on a novel bioinspired surface-enhanced Raman scattering substrate, which can directly detect dye molecular residues and food-borne pathogen microorganisms in the environment. The surface-enhanced Raman scattering platform consists of a natural diatomite microporous array decorated with a metal-phenolic network that enables the in situ reduction of gold nanoparticles. The as-prepared nanocomposites display excellent surface-enhanced Raman scattering activity with the lowest limit of detection and the maximum Raman enhancement factor of dye molecules up to 10⁻¹¹ M and 1.18 × 10⁷, respectively. For food-borne bacterial detection, a diatomite microporous array decorated with a metal polyphenol network and gold nanoparticle-based surface-enhanced Raman scattering analysis is capable of distinguishing the biochemical fingerprint information of Staphylococcus aureus and Escherichia coli, indicating the great potential for strain identification.