Biomaterials Science最新文献

Microrobots hold broad application prospects in the field of precision medicine, such as intravenous drug injection, tumor resection, opening blood vessels and imaging during abdominal surgery. However, the rapid and controllable preparation of biocompatible hydrogel microparticles still poses challenges. This study proposes the one-step direct acquisition of biocompatible sodium alginate and gelatin methacrylate (GelMA) hydrogel microparticles using an oil-free aqueous solution, ensuring production with a controllable generation frequency. An adaptive interface shearing platform is established to fabricate alginate/GelMA microparticles using a mixture of the hydrogel, photoinitiator, and Fe₃O₄ nanoparticles (NPs). By adjusting the static magnetic field intensity (B_s), vibration frequency, and flow rate (Q) of the dispersed phase, the size and morphology of the hydrogel microparticles can be controlled. These hydrogel microparticle robots exhibit magnetic responsiveness, demonstrating precise rotating and rolling movements under the influence of an externally rotating magnetic field (RMF). Moreover, hydrogel microparticle robots with a specific critical frequency (C_f) can be customized by adjusting the B_s and the concentration of Fe₃O₄ NPs. The directional in situ untethered motion of the hydrogel microparticle robots can be successfully realized and accurately controlled in the climbing over obstacles and in vitro experiments of animals, respectively. This versatile and fully biodegradable microrobot has the potential to precisely control movement to bone tissue and the natural cavity of the human body, as well as drug delivery.

Carbon-derived compounds are gaining traction in the scientific community because of their unique properties, such as conductivity and strength, and promising innovations in technology and medicine. Graphitic nitride carbon (g-C₃N₄) stands out among these compounds because of its potential in antitumor therapies. This study aimed to assess g-C₃N₄'s antitumor potential and cytotoxic mechanisms. Prostate cancer (DU-145) and glioblastoma (U87) cell lines were used to evaluate antitumor effects, whereas RAW 264.7 and HFF-1 non-tumor cells were used for selectivity evaluation. The synthesized g-C₃N₄ particles underwent comprehensive characterization, including the assessment of particle size, morphology, and oxygen content, employing various techniques, such as X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, and atomic force microscopy. The results indicated that g-C₃N₄ significantly affected tumor cell proliferation and viability, exhibiting high cytotoxicity within 48 h. In non-tumor cells, minimal effects on proliferation were observed, except for damage to the cell membranes of RAW 264.7 cells. Moreover, g-C₃N₄ changed the cell morphology and ultrastructure, affecting cell migration in U87 cells and potentially enhancing migration in RAW 264.7 cells. Biochemical assays in Balb/C mice revealed alterations in alanine aminotransferase, aspartate aminotransferase, and amylase levels. In conclusion, g-C₃N₄ demonstrated promising antitumor effects with minimal toxicity to non-tumor cells, suggesting its potential in neoplasm treatment.

Ionizable lipid nanoparticles have demonstrated remarkable success as mRNA vaccine carriers and represent one of the most promising gene drug delivery vehicles. However, polyethylene glycol (PEG), one of the major components, can cause immunogenic reactions, anaphylaxis and increased blood clearance, leading to toxic side effects and reduced efficacy. In this study, we utilize polysorbate 80 (PS80) as a PEG alternative in formulating eGFP mRNA-loaded ionizable lipid nanoparticles (PS80-iLNPs), aiming to enhance stealth properties, uptake efficiency, and biosafety. Our findings revealed that PS80-iLNPs enhanced the stealthiness and resistance to serum interference. Compared to PEG-containing ionizable lipid nanoparticles (PEG-iLNPs), PS80-iLNPs showed a 1.14-fold increase in stealthiness. Moreover, at a total lipid concentration of 50 μg mL⁻¹, PS80-iLNPs exhibited 1.12 times higher cell viability compared to PEG-iLNPs. Notably, under serum interference, PEG-iLNPs showed a 44.97% uptake reduction, whereas PS80-iLNPs exhibited a modest 30.55% decrease, underscoring its superior serum resistance. This work demonstrated that PS80 could serve as a suitable substitute for PEG, thus signifying an excellent basis for the development of PEG-free ionizable lipid nanoparticles.

Many applications of biomaterials require hydrophilic polymers as building blocks, including hydrogels and nanomedicinal devices. Besides enabling sufficient swelling properties in aqueous environments, hydrophilic polymers provide hydration layers, which are considered a major requirement when designing non-fouling surfaces and materials. For the last few decades, polyethylene glycol has been seen as the gold standard for such applications. However, reports on its stability and immunogenicity have urged chemists to identify alternatives with comparable or superior properties. In addition to biopolymers, zwitterionic polymers have gained increasing attention by effectively offering an overall charge-neutral scaffold capable of forming strong hydration layers. Driven by an enhanced understanding of the structure–property relationship of zwitterionic materials, poly(ylides) have emerged as a new class of hydrophilic and charge-neutral polymers. By having the negative charge adjacent to the positive charge, ylides offer not only a minimal dipole moment but also maintain their overall charge-neutral nature. Despite some early reports on their synthesis during the 1980s, polymeric ylides were largely overlooked as a class of polymers, and their utility as unique hydrophilic building blocks for the design of biomaterials and nanomedicinal tools remained elusive. In recent years, several groups have reported N-oxide and carbon-centered ylide-based polymers as highly effective building blocks for the design of antifouling materials and nanomedicines. Here, by reviewing recent progress and understanding of structure–property relationships, arguments are provided explaining why polymeric ylides should be classified as a standalone class of hydrophilic polymers. Consequently, the author concludes that the term ‘poly(ylide)’ or ‘polymeric ylides’ should be routinely used to adequately describe this emerging class of polymers.

Nanozymes are a class of nanomaterials with enzyme-like activity that can mimic the catalytic properties of natural enzymes. The small size, high catalytic activity, and strong stability of nanozymes compared to those of natural enzymes allow them to not only exist in a wide temperature and pH range but also maintain stability in complex environments. Recently developed single-atom nanozymes have metal active sites composed of a single metal atom fixed to a carrier. These metal atoms can act as independent catalytically active centers. Metal single-atom nanozymes have a homogeneous single-atom structure and a suitable coordination environment for stronger catalytic activity and specificity than traditional nanozymes. The antioxidant metal single-atom nanozymes with the ability of removing reactive oxygen species (ROS) can simulate superoxidase dismutase, catalase, and glutathione peroxidase to show different effects in vivo. Furthermore, due to the similar structure of antioxidant enzymes, a metal single-atom nanozyme often has multiple antioxidant activities, and this synergistic effect can more efficiently remove ROS related to oxidative stress. The versatility of single-atom nanozymes encompasses a broad spectrum of biomedical applications such as anti-oxidation, anti-infection, immunomodulatory, biosensing, bioimaging, and tumor therapy applications. Herein, the nervous, circulatory, digestive, motor, immune, and sensory systems are considered in order to demonstrate the role of metal single-atom nanozymes in biomedical antioxidants.

Non-alcoholic fatty liver disease (NAFLD) is a form of hepatic steatosis in which more than 5% of the liver's weight is fat, primarily due to the overconsumption of soft drinks and a Western diet. In this study, we investigate the potential of plant-derived exosome-like nanovesicles (PENs) to prevent liver fibrosis and leaky gut resulting from NAFLD. Specifically, we examine whether hemp sprout-derived exosome-like nanovesicles (HSNVs) grown on smart farms could exert protective effects against NAFLD by inhibiting liver fibrosis. HSNVs ranging from 100–200 nm were measured using nanoparticle tracking analysis (NTA). HSNVs (1 mg kg⁻¹) were orally administered for 5 weeks to mice with NAFLD induced by feeding them a Western diet (WD; a fat- and cholesterol-rich diet) and fat-, fructose-, and cholesterol-rich (FFC) diet for 8 weeks. Importantly, the administration of HSNVs markedly reduced oxidative stress and fibrosis marker proteins in NAFLD mouse models and LX2 cells. Furthermore, treatment with HSNVs prevented a significant decrease in the quantity of gut barrier proteins and endotoxin levels in NAFLD mouse models. For the first time, these results demonstrate that HSNVs can exhibit a hepatoprotective effect against gut leakiness and WD/FFC-induced liver fibrosis by inhibiting oxidative stress and reducing fibrosis marker proteins.

Soft tissue engineering and regenerative medicine aim to address the intricate relationship between tissue architecture and biomechanical performance. The traditional technique used to analyze muscular architectures is histology. However, optical coherence tomography is a novel non-destructive, non-invasive imaging tool that provides real-time, high-resolution visualization of tissue microstructure, making it applicable to soft tissues. High-quality images, minimized light scattering, and different clearing agents, such as propylene glycol and iodixanol, have been employed. A stress–relaxation test was performed to characterize the effects of clearing agents on rat extensor digitorum longus and soleus muscles. Additionally, muscle fiber structure images obtained using optical correlation tomography were compared with histological images to corroborate the high precision of the optical method. The results showed that iodixanol is a promising clearing agent for characterizing muscles as it provides good quality images and a satisfactory reversibility process with no permanent damage to the extracellular matrix or muscle fiber structure of the tissue.

Searching for materials that accurately mimic the optical properties of biological tissues is essential, particularly for transcranial photobiomodulation (PBM) research, where it is necessary to comprehend how light propagates through the head tissues. In this research, we characterised, in the 500–1200 nm range, the transmittance spectra of porcine tissues (skin, muscle, cranium, brain, and cerebellum) and different agarose-based phantoms. These phantoms were developed using different combinations of titanium dioxide (TiO₂), India ink, organometallic compounds, and laser-ablated gold and zinc oxide nanoparticles. The surface and mechanical properties of these phantoms were also characterized. The results showed that an increased TiO₂ concentration decreased the optical transmittance of the phantoms. However, when TiO₂ was added to the India ink and laser-ablated nanoparticles’ phantoms, not only did it reduce transmittance amplitude, but it also flattened its spectra. Comparing the phantoms and biological tissues’ results, the spectral profiles of TiO₂ samples appeared similar to those of muscle, skin, and brain/cerebellum; organometallic compounds replicated the skin and muscle curves; India ink emulated skin and cranium; and the laser-ablated nanoparticles mimicked the muscle. Although it was possible to establish qualitative similarities between the phantoms and the biological tissues’ optical transmittance spectra, there is a need for further studies with different components’ combinations to ascertain curves that more closely mimic the biological tissues.

The field of bone repair and regeneration has undergone significant advancements, yet challenges persist in achieving optimal bone implants or scaffolds, particularly load-bearing bone implants. This review explores the current landscape of bone implants, emphasizing the complexity of bone anatomy and the emerging paradigm of biomimicry inspired by natural structures. Nature, as a master architect, offers insights into the design of biomaterials that can closely emulate the mechanical properties and hierarchical organization of bone. By drawing parallels with nacre, the mollusk shells renowned for their exceptional strength and toughness, researchers have endeavored to develop bone implants with enhanced biocompatibility and mechanical robustness. This paper surveys the literature on various nacre-inspired composites, particularly ceramic/polymer composites like calcium phosphate (CaP), which exhibit promising similarities to native bone tissue. By harnessing the principles of hierarchical organization and organic–inorganic interfaces observed in natural structures, researchers aim to overcome existing limitations in bone implant technology, paving the way for more durable, biocompatible, and functionally integrated solutions in orthopedic and dental applications.