ACS Applied Bio Materials最新文献

Piezoelectric materials, renowned for their ability to convert mechanical energy into electrical energy, have gained attention for their potential in biomedical applications. In particular, piezoelectric nanoparticles, such as barium titanate nanoparticles, hold great promise for treating neurologically related diseases. In this study, barium titanate piezoelectric nanoparticles are used as stimulators to directly treat epileptic neurons. After being modified by polyethylene glycol, barium titanate nanoparticles have shown excellent biocompatibility and dispersibility. Furthermore, such nanoparticles offer wireless piezoelectric stimulation to neurons in response to low-intensity pulsed ultrasound. More importantly, our experiments reveal that piezoelectric stimulation immediately reduces neuronal intracellular calcium concentration and restores cell viability. These effects are attributed to the opening of voltage-gated calcium channels and the release of active substances. These findings offer insights into the potential of piezoelectric stimulation as an approach for epilepsy treatment and enhance our understanding of the mechanisms underlying electrical stimulation in epileptic neurons.

The immune system is imperative to the survival of all biological organisms. A functional immune system protects the organism by detecting and eliminating foreign and host aberrant molecules. Conversely, a dysfunctional immune system characterized by an overactive or weakened immune system causes life-threatening autoimmune or immunodeficiency diseases. Therefore, a critical need exists to develop technologies that regulate the immune system to ensure homeostasis or treat several diseases. Accumulating evidence shows that biomaterials─artificial materials (polymers, metals, ceramics, or engineered cells and tissues) that interact with biological systems─can trigger immune responses, offering a materials science-based strategy to modulate the immune system. This Review discusses the expanding frontiers of biomaterial-based immunomodulation, focusing on principles for designing these materials. This Review also presents examples of immunomodulatory biomaterials, which include polymers and metal- and carbon-based nanomaterials, capable of regulating the innate and adaptive immune systems.

This Perspective explores the potential of nonpsychoactive cannabinoids (NPCs) such as CBD, CBG, CBC, and CBN in developing innovative biomaterials for biomedical and sports applications. It examines their physicochemical properties, anti-inflammatory, analgesic, and neuroprotective effects, and their integration into various biomaterials such as hydrogels, sponges, films, and scaffolds. It also discusses the current challenges in standardizing formulations, understanding long-term effects, and understanding their intrinsical regulatory landscapes. Further, it discusses the promising applications of NPC-loaded materials in bone regeneration, wound management, and drug delivery systems, emphasizing their improved biocompatibility, mechanical properties, and therapeutic efficacy demonstrated in vitro and in vivo. The review also addresses innovative approaches to enhance NPC delivery including the use of computational tools and explores their potential in both biomedical and sports science contexts. By providing a comprehensive overview of the current state of research, this review aims to outline future directions, emphasizing the potential of NPCs in biomaterial science and regenerative medicine.

The limitations of individual imaging modalities have led to significant interest in hybrid imaging methods that combine the advantages of multiple techniques. The development of diverse dual imaging agents, which offer the exceptional sensitivity of single-photon emission computed tomography (SPECT) and the high spatial resolution of magnetic resonance imaging (MRI), has been addressing the demand for more advanced diagnostic pharmaceuticals. In this study, ^99mTc-labeled manganese oxide-loaded mesoporous silica nanoparticles (MSNs), conjugated with folic acid as the targeting moiety and the chelating agent H₂pentapa-en-NH₂ (^99mTc-MnO_x-MSN-FA-pa), were developed for targeted SPECT-MRI dual imaging. The toxicity of the nanoparticles was confirmed through an MTT assay, showing >90% viability in HEK-293 and MDA-MB-231 cells at concentrations up to 200 μg/mL, indicating nonsignificant toxicity. Cellular uptake studies showed that folic acid functionalization effectively accentuated tumor-specific intracellular uptake of nanoparticles in MDA-MB-231 cells through folate receptor-mediated endocytosis. Additionally, the radiolabeling yield of ^99mTc-MnO_x-MSN-FA-pa was found to be 99.6 ± 0.8% (n = 3), and the pH-responsive release of paramagnetic manganese ions increased the r₁ relaxivity of the nanoprobe to 11.37 mM^-1 s^-1. In vivo SPECT imaging demonstrated rapid tracer accumulation in MDA-MB-231 xenografts, with a tumor-to-muscle ratio of 6.01 ± 0.51 at 2 h, and minimal uptake in nontargeted organs. In vivo MRI studies indicated the strongest tumor contrast at 2 h postinjection. Given its desirable contrast enhancement in T₁ MRI and SPECT imaging, along with low toxicity, MnO_x-MSN-FA-pa shows potential as an effective multifunctional nanoprobe for precise tumor imaging.

In this study, poly(vinyl alcohol) (PVA)/silk fibroin particle (SFP) hydrogel scaffolds are prepared by mixing compound calcium phosphate (CCP) in different weight ratios (0, 4, 8, and 16%) via the repeated freeze-thawing method. The physicochemical characteristics and biological behavior of the hydrogel are evaluated, and the results show a decreased porous structure of the hydrogel composite with a swelling ability upon CCP addition; however, the mechanical strength and degradation rate increase. Cell attachment and growth analyses demonstrate PVA/SFP/CCP as nontoxic to cells. Furthermore, osteogenesis evaluation shows that the group with 8% CCP in PVA/SFP hydrogel exhibits higher cell adhesion and proliferation than other groups. Additionally, the group exhibits better osteogenic performance than the other groups when alkaline phosphatase activity, total protein content, and calcium deposition are compared. Considered as a mixture, the PVA/SFP/CCP hydrogel is promising for bone tissue engineering applications; particularly, PVA/SFP/8% CCP serves as an optimal choice.

Medical devices composed of titanium (Ti) should exhibit antibacterial and osteogenic activities to achieve both infection prevention and rapid bone reconstruction. Here, a Ti surface was modified by performing magnetron sputtering (MS) using pure Mg or Mg-30Ca alloy targets for surface functionalization. MC0, prepared with a pure Mg target, had a crystalline metallic-Mg coating layer, whereas MC30, prepared with an Mg-30Ca alloy target, had an amorphous coating composed of Mg and Ca. Both samples rapidly dissolved when immersed in a cell culture medium and exhibited antibacterial activities against methicillin-resistant Staphylococcus aureus and cytotoxicity against MC3T3-E1 cells. Furthermore, MC30 promoted the proliferation and calcification of MC3T3-E1 cells because of the subsequent deposition of calcite on the surface after rapid dissolution. Our findings are the first to reveal that MS performed by using an Mg-30Ca alloy target endowed Ti surfaces with functional changes from antibacterial to osteogenic activities over time. Our results provide fundamental insights into the surface design of Ti-based medical devices for enhanced bone reconstruction and infection prevention and offer possibilities for biomedical applications of Mg-based coatings.

Soft materials are crucial for epidermal interfaces in biomedical devices due to their capability to conform to the body compared to rigid inorganic materials. Gels, liquids, and polymers have been extensively explored, but they lack sufficient electrical and thermal conductivity required for many application settings. Gallium-based alloys are molten metals at room temperature with exceptional electrical and thermal conductivity. These liquid metals and their composites can be directly applied onto the skin as interface materials. In this Spotlight on Applications, we focus on the rapidly evolving field of liquid metal-enabled epidermal interfaces featuring unique physical properties beyond traditional gels and polymers. We delve into the role of liquid metal in electrical and thermal biointerfaces in various epidermal applications. Current challenges and future directions in this active area are also discussed.

Recent advances have been made in second near-infrared (NIR-II) fluorescence bioimaging and many related applications because of its advantages of deep penetration, high resolution, minimal invasiveness, and good dynamic visualization. To achieve high-performance NIR-II fluorescence bioimaging, various materials and probes with bright NIR-II emission have been extensively explored in the past few years. Among these NIR-II emissive materials, conjugated polymers and conjugated small molecules have attracted wide interest due to their native biosafety and tunable optical performance. This review summarizes the brightness strategies available for NIR-II emissive conjugated materials and highlights the recent developments in NIR-II fluorescence bioimaging. A concise, detailed overview of the molecular design and regulatory approaches is provided in terms of their high brightness, long wavelengths, and superior imaging performance. Then, various typical cases in which bright conjugated materials are used as NIR-II probes are introduced by providing step-by-step examples. Finally, the current problems and challenges associated with accessing NIR-II emissive conjugated materials for bright NIR-II fluorescence bioimaging are briefly discussed, and the significance and future prospects of these materials are proposed to offer helpful guidance for the development of NIR-II emissive materials.

Tumor exosomes, known as maternal cell messengers, play an important role in cancer occurrence, proliferation, metastasis, immune escape, drug resistance, and other processes and are an entry point for cancer research. However, there is still a lack of an efficient detection technology for exosomes. In this study, the ultrahigh sensitivity SERS nanoprobe with a three dimensional (3D) magnetic core/Au nanocolumn/Au nanoparticles shell strongly coupling multistage structure (Fe₃O₄@NR-NPs) was constructed by crystal growth of nanocrystals in the confined space of a central radiating single particle mesoporous molecular sieve channel and strong coupling secondary growth of gold particles. The exosomes were confined onto the "hot spot" of plasmonic nanoparticles and rapidly enriched by CD63 antibody functional-Fe₃O₄@NR-NPs to achieve high sensitivity detection, with the limit of detection of 1 × 10³ particles/mL (S/N = 3). The spectral data set of different exosomes is applied to train for multivariate classification of cell types and to estimate how the normal exosome data resemble cancer cell exosomes by principal component analysis (PCA). Finally, this detection method has also been successfully employed for the detection of exosomes in complex samples; this proves that the proposed SERS-based method is a promising tool for clinical cancer screening.