搜索结果：Biointerphases

Poly(vinylidene fluoride) (PVDF) is widely used in neural tissue engineering for its strong piezoelectric response, yet its nonbiodegradability and environmental persistence limit its clinical translation. Neural regeneration demands scaffolds that not only replicate the extracellular matrix but also deliver bioelectrical cues to guide neuronal growth. Here, we introduce aligned electrospun fibers of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and cellulose acetate (CA) as biodegradable, sustainable alternatives to PVDF for studying how piezoelectricity, surface charge, and nanotopography influence neuronal function. Compared to polycaprolactone (PCL) as a nonpiezoelectric control, the PVDF, PHBV, and CA scaffolds exhibited distinct morphologies and progressively decreasing piezoelectric coefficients. All supported robust adhesion and proliferation of B35 neuronal cells; however, piezoelectric fibers significantly enhanced intracellular Ca2+ influx, neurite elongation, and β3-tubulin expression. Both PVDF and PHBV activated the WNT/GSK3β signaling pathway and downregulated the pro-apoptotic BAX/BCL-2 ratio, suggesting enhanced neuroprotective capacity. Notably, while PVDF induced strong Ca2+-mediated neuronal maturation through piezoelectric stimulation, PHBV elicited additional antiapoptotic effects, likely linked to 3-hydroxybutyrate metabolism. Together, these findings demonstrate that combining nanoscale alignment, surface charge, and intrinsic piezoelectricity generates a bioelectrically active microenvironment conducive to neuronal regeneration. Importantly, PHBV emerges as a sustainable, biodegradable alternative to PVDF, bridging environmental responsibility with functional performance in neural tissue engineering.

Efficient illumination and light management are increasingly important in modern society. Biomimetic strategies inspired by biological optical systems have, therefore, attracted considerable attention for the development of novel photonic devices. This study investigates light control mechanisms in the photophores of the bioluminescent deep-sea bristlemouth Sigmops gracilis (Gonostomatidae). The reflection and scattering properties of photophores were examined under external illumination. Strong light scattering from guanine platelets was observed on the photophore surface. The observed scattering behavior was successfully reproduced using a biomimetic model consisting of multiple aligned thin chambers containing guanine platelets suspended in water, demonstrating that multilayered platelet assemblies significantly enhance reflectivity. These results indicate that the accumulation of guanine platelets at the photophore surface contributes to increased light intensity around the photophore. In addition, guanine platelets exhibiting anisotropic directional scattering, similar to that observed on the fish body surface, were reconstructed using a magnetic rotation method. Together with previous findings on internal photophore components, these results suggest that external photophore structures in bioluminescent deep-sea fish provide an effective biomimetic strategy for the efficient reuse and redirection of light emitted from photocytes.

Ant middens represent accumulations of discarded materials and provide insight into colony-level foraging and processing behavior. While middens of granivorous ants are typically dominated by plant material, animal remains are occasionally present, yet their origin and mechanical basis remain poorly understood. Here, we investigated the occurrence of gastropod shells in an external midden of the harvester ant Messor wasmanni and evaluated ant mandible mechanics to provide some background for shell fracturing. Midden material was collected during three sampling events and sorted by material type and size. Snail shells were identified to either genus or species level, fracture locations were documented, and representative shells were fractured experimentally using major worker mandibles to quantify shell-breaking forces. The forces varied widely depending on snail species, growth stage, and fracture location, with juvenile shells and mechanically weak regions fracturing at substantially lower forces than adult shells or their reinforced regions. Nanoindentation revealed strong regional and caste-specific differences in mandible mechanical properties, with highest hardness and Young's modulus at the masticatory margin of major workers. Elemental analyses showed enrichment of zinc and other metals in cutting edges, consistent with enhanced wear resistance. This study integrates ecological, mechanical, and material data to provide a mechanistic framework for interpreting snail shell occurrence in ant middens.

Biliary stents are medical devices inserted into the bile duct to treat biliary strictures. However, inserted stents can become occluded within a few months after placement. In this study, the inner surface of a polyethylene (PE) tube was plasma-treated with helium (He), nitrogen (N2), oxygen (O2), and their gas mixtures to improve resistance to stent occlusion. Surface characteristics were analyzed by water contact angle (WCA) and x-ray photoelectron spectroscopy (XPS) measurements. In the WCA results, bare PE without plasma treatment was the most hydrophobic at 100.7°, whereas PE(He) plasma-treated with He gas became the most hydrophilic at 26.1°. XPS deconvolution analysis revealed that the PE(He) and PE(He/N2) contained a considerable proportion of O 1s present as amide (-CONH-) groups exceeding 40%, whereas the other samples had proportions below 7%. The resistance to stent occlusion was verified through microbial and cancer cell adhesion assays. In the microbial adhesion assay, Escherichia coli (E. coli) was used, and PE(He) showed a statistically significant reduction in E. coli growth compared to bare PE. Inhibition of cancer cell adhesion was the most pronounced in PE(He) and PE(He/N2), with reductions in fluorescence intensities of 75.5% and 81.5%, respectively. Overall, both surface hydrophilization and amidation were found to be effective in inhibiting the adhesion of organic contaminants. It was proposed that plasma surface treatment has the potential to improve resistance to biliary stent occlusion.

Hydrogels are high-water-content polymer networks similar to those of soft tissues and have shown immense potential in fields such as tissue engineering, flexible electronics, and intelligent sensors. However, traditional hydrogels still face challenges such as low mechanical strength, poor toughness, and susceptibility to fatigue. Inspired by tough natural soft tissues (such as muscles and tendons), the introduction of a robust fibrous network into hydrogels enables effective stress transfer, crack bridging, and energy dissipation, thus overcoming the mechanical limitations of traditional hydrogels. This paper reviews fiber-reinforced hydrogels prepared from different reinforcing fibers (e.g., natural, synthetic, inorganic, and carbon-based), as well as the interfacial interactions between the fibers and the matrix (including physical entanglement, dynamic noncovalent bonds, and covalent bonds), and summarizes the preparation methods, such as in situ infiltration, directional freezing, and 3D printing. It also discusses their applications in the fields of medicine, sensing, and wearable devices and finally provides an outlook on current challenges such as precise interface regulation and large-scale intelligent manufacturing.

Mollusks, and their particularly diverse class Gastropoda, owe much of their ecological success due to the evolution of their radula-a specialized feeding apparatus. This structure, composed of a chitinous membrane and sometimes mineralized teeth, plays a critical role in food acquisition and processing across a wide range of habitats. The radula's morphology, material composition, and mechanical properties exhibit remarkable diversity and functional optimization, shaped by millions of years of evolutionary refinement. Adaptive variations in tooth shape, composite material content (often rich in iron, calcium, silicon, or other elements), mechanical properties, and coordinated interaction among radular components enable mollusks to withstand strong contact forces, minimize structural failure and tooth wear, and thrive in distinct ecological niches. This review synthesizes current insights into the structure and mechanical properties of the radula teeth, highlighting its adaptations to the preferred ingesta and the functional principles of the teeth. In the course of adaptation to similar physical constraints of the ingesta, different solutions evolved independently. Besides main aspects interesting for ecological research and organismic biology, the radula's structural intelligence and efficiency present a rich source of inspiration for biomimetic innovation.

Real-time monitoring of biological barrier integrity is crucial for drug development and disease modeling. The gold-standard technique, transendothelial electrical resistance (TEER), is often limited by the cost and complexity of commercial alternating current systems. To address this, we developed a novel, low-cost biosensor based on a direct current (DC) series voltage division principle, featuring custom hardware and open-source firmware. Validation demonstrated a wide dynamic range (155-105 600 Ω cm2) and high accuracy (±3%). The device showed excellent correlation with a commercial EVOM3 system in monitoring TEER trends during endothelial barrier formation and oxidative stress-induced disruption. Biosensor readings were consistent with barrier kinetics captured by xCelligence RTCA and live-cell imaging. Furthermore, a strong negative correlation was established between decreasing TEER values and increasing paracellular leakage of sodium fluorescein. These results collectively validate our DC-based system as a reliable, accurate, and accessible tool for quantifying in vitro barrier integrity, with significant potential to democratize research in biomedicine and toxicology.

The Langmuir monolayer technique has proven to be an effective method for constructing lipid-based models of cell membranes. Compared to other artificial membrane systems, such as liposomes or supported lipid bilayers, it offers a relatively simple and versatile approach to reconstructing lipid components of biological membranes and systematically modifying their composition. The technique allows precise control over experimental parameters such as surface pressure and temperature, which influence the physical state and organization of lipid monolayers. Lipid monolayer models are widely used to investigate molecular interactions at membrane interfaces, including the effects of biomolecules or xenobiotics on membrane properties, identification of potential molecular targets of drugs, and evaluation of mechanisms underlying their pharmacological activity or toxicity. While the successful application of the monolayer technique in lipid membrane modeling has been extensively reported in the literature, comprehensive discussions of lipid compositions for modeling various membrane types-such as eukaryotic, prokaryotic, viral, and pathological membranes-remain limited. In particular, systematic descriptions of lipid mixtures used to model membranes characteristic of eukaryotic cells, prokaryotes, viruses, or pathological states are limited. The aim of this review is to address this gap by summarizing lipid compositions used in Langmuir monolayer models designed to mimic different biological membrane types.

Specialized bacteria can effectively nucleate ice crystals using ice nucleating proteins (INPs) anchored to the cell surface. Biogenic freezing has several applications, from snow making to cryo-medicine and freeze/antifreeze materials. For biomimetic designs of INP analogs, it is important to understand how the proteins involved in the process bind to material surfaces. In this study, we determine the binding of a model INP to hydrophobic self-assembled monolayers (SAMs) as well as hydrophilic carboxyl-terminated SAMs. INPs are large proteins with more than 1200 amino acids and a long series of repeat units. Since full-length INPs are difficult to produce and handle, we have investigated a shorter model INP dubbed InaZ9R, which has nine repeat units and still folds into the hallmark beta-helix structure known from the full-length protein. Combining x-ray photoelectron spectroscopy and near-edge x-ray absorption fine structure spectroscopy, we find that InaZ9R form closely packed monolayers on both hydrophilic and hydrophobic surfaces. Angle-resolved nitrogen K-edge near-edge x-ray absorption fine structure spectra show a high degree of orientational order associated with the native β-sheet structure.

This Special Topic Collection brings together a diverse and timely collection of contributions that reflect the expanding frontiers of biointerfaces research in India. We are deeply grateful to all the authors for their contributions. This collection explores themes that are both fundamental in scope and closely aligned with pressing biomedical challenges, including cancer metastasis, drug delivery, genetic disorders, and biomaterials design. We briefly highlight the key findings in each of the contributions that make up this collection.

This study provides in-depth insights into the thermodynamics of electrochemical processes that govern the generation and temporal modulation of open-circuit potentials in biofilms and presents the foundation and applications of open-circuit potential methods to study the bioelectrochemical behaviors of biofilms. This investigation was guided by an overarching hypothesis that models should adequately explain the open-circuit potential patterns generated by biofilms when environmental conditions change; and from this work, a generalized model of electrochemical processes endemic to the biofilm electrode was developed and validated. The proposed model accounts for open system thermodynamics and the kinetics of bioelectrochemical transformations, and the model is simplified to enable applicability to a wide range of processes that are possible within biofilms. As such, the model can account for different parameters associated with various biofilm systems and is extendable to include numerous other experimental conditions. The model predictions were compared to the experimental data generated by 48 equidistantly located microbial potentiometric sensor electrodes in a chamber capable of simulating naturally occurring water matrix, which was exposed to environmental conditions. By combining electrochemical-cell thermodynamics and kinetics approaches, the model explained the temporal dependences of the open circuit potentials in aerobic and anaerobic conditions and the interconversion of two regimes commonly observed in natural systems. At the same time, it enables extraction of the relevant kinetic parameters from experimentally measured time evolution of the open circuit potentials.

Protein-mediated underwater adhesion is vital for the survival of many aquatic organisms and plays central roles in biofouling and bioinspired material development. Metal ions are known to influence underwater adhesion by regulating cohesion between adhesive proteins and interactions at the underwater material interface. However, direct mechanistic evidence of Ca2+ involvement in adhesion of marine organisms remains insufficient. In this study, we investigated the role of Ca2+ in permanent underwater adhesion of ascidian adhesive protein 1 (AAP1), an adhesive protein identified from the ascidian Ciona robusta, a model marine invasive fouling species. Using in vitro experiments, we examined AAP1's cohesion and interfacial adhesion under varying Ca2+ concentrations (0, 1.0, 2.5, 5.0, 10.0, and 25.0 mM). Our results indicated that Ca2+ mediated both cohesion and interfacial adhesion in a concentration-dependent manner. Protein aggregation was induced at 10.0 and 25.0 mM, with denser aggregation at higher concentrations. Surface force apparatus measurements showed a peak in cohesion energy at 25.0 mM Ca2+, while interfacial adhesion energy reached a maximum at 10.0 mM. These results suggest that Ca2+ may facilitate cohesion via salt bridge formation and promote interfacial adhesion by mediating electrostatic interactions between AAP1 and material surfaces. Additionally, the cohesion of AAP1 may enhance molecular alignment on surfaces, contributing its interfacial adhesion. Overall, our results provide direct evidence for the involvement of Ca2+ in protein-mediated ascidian underwater adhesion. These findings will deepen our understanding of the mechanisms of underwater adhesion in aquatic organisms and guide the future development of antifouling strategies and bioinspired underwater adhesives.

This study evaluates the clinical outcomes associated with the use of an improved polyetheretherketone (PEEK) cranial plate in cranioplasty surgery. A total of 104 patients were involved, with significant findings revealing a reduced incidence of postoperative adverse reactions in the improved PEEK group (28.85%) compared to the conventional PEEK group (50.00%, P&#x2009;=&#x2009;0.027). Patient satisfaction rates were markedly higher in the improved PEEK cohort (P&#x2009;<&#x2009;0.05). Although the medical expenses for the enhanced PEEK group were greater (&#xa5; 144&#x2009;600&#x2009;&#xb1;&#x2009;21&#x2009;200 vs &#xa5; 127&#x2009;400&#x2009;&#xb1;&#x2009;20&#x2009;100, P&#x2009;<&#x2009;0.05), there were no notable differences in cerebral blood flow perfusion or survival time between the two groups (P&#x2009;>&#x2009;0.05). The conclusions indicate that while the enhanced PEEK cranial plates incur higher upfront costs, their benefits in terms of safety and patient satisfaction, along with improved implant stability and bone healing, support their use in clinical practice. Consequently, the upgraded PEEK material is recommended for cranioplasty procedures.

Indirect co-culture, wherein two distinct cell types are cultivated within the same medium without direct contact, remains a relatively underexplored approach in biomaterials science for simulating physiological cell-cell interactions on material surfaces in vitro. In this study, human mesenchymal stem cells (hMSCs) were cultured on two types of Ti6Al4V substrates (polished and sand-blasted/acid etched) in a co-culture system using conditioned osteogenic differentiation media (cOBM), enriched with soluble factors secreted by human osteoblasts (hOBs). The combined impact of surface microtopography of Ti6Al4V substrates and cOBM supplementation has resulted in the modulation of cell morphology, alkaline phosphatase (ALP) activity, and calcium phosphate mineralization. Enhanced mineralization (2.5-fold increase compared to baseline at day 21) was observed on Ti6Al4V substrates when hMSCs were cultured in the presence of cOBM. This was accompanied by a peak expression of the early osteogenic marker, ALP by day 14. The synergistic behavior of sandblasted and acid-etched substrates with soluble biochemical cues, derived from hOBs showcased their potential for augmenting osteogenic differentiation. The in vitro outcomes were validated in a rabbit model study, which clearly demonstrated better osseointegration of sand-blasted/acid etched implants over 12 weeks.

The lack of cementum in peri-implant tissues leads to a deficiency in anchorage points for gingival collagen fibers. This arrangement is linked to reduced protective capabilities compared to teeth. Therefore, there is a pressing need to develop surfaces that optimize the interaction between soft tissue and implants. 3D-printed titanium disks (Ti3DP), machined disks (TiMC), and glass coverslips (GS) were seeded with human gingival fibroblasts. These specimens underwent mechanical characterization via roughness and wettability assays. Biological characterization included assessments of cellular viability (live/dead), adhesion and spreading (F-actin), cell count (DAPI), cellular metabolism (Alamar blue), adhesive strength, and soluble collagen and total protein quantification up to 14 days. Data analysis employed Student's t-test and ANOVA post-hoc Tukey test (&#x3b1;&#x2009;=&#x2009;0.05). The group TiMC exhibited higher hydrophilicity and lower roughness compared to Ti3DP. All groups demonstrated cellular viability throughout the study period. Adhesive strength did not significantly differ among groups; however, cell count was higher in TiMC and GS after one day of cell seeding in comparison to Ti3DP. Morphologically, GS and TiMC displayed more fusiform cells with a uniform distribution, while Ti3DP showed smaller, irregular cells with multiple lamellipodia and filopodia. Additionally, statistically superior collagen and total protein deposition was observed in Ti3DP (p&#x2009;<&#x2009;0.01). The 3D-printed titanium surface allowed human gingival fibroblasts to adhere to it, leading to a 3D cytoskeleton morphology that culminated in increased collagen expression. Therefore, these 3D-printed devices present a promising avenue for producing transmucosal components due to their increase in collagen production.

We aimed to synthesize modified magnesium nanowire (Ti-NW-Mg) on the surface of titanium implants and to investigate its effects on bone binding by regulating macrophage polarization in vitro. The Ti-NW-Mg was synthesized from smooth titanium (CP-Ti) by hydrofluoric acid etching and high temperature alkalization, and then through the displacement reaction of magnesium sulfate solution with the titanium surface. The control groups were CP-Ti, sandblasted and etched with acid titanium (Ti-SLA), and only for micro/nano-modified titanium surfaces (Ti-NW). The physicochemical properties of the Ti-NW-Mg surface were examined. The biological effects of materials on RAW264.7 cells were compared, and the effects on osteogenesis by mediating RAW264.7 polarization were discussed. We observed the effect of the materials on osteogenesis through immunohistochemistry. In this experiment, the Ti-NW-Mg surface was interwoven into a nanotopological network, which released a specific concentration of magnesium ions and had good hydrophilicity. Compared to CP-Ti, Ti-SLA, and Ti-NW, Ti-NW-Mg reduced the proliferation of macrophages on the surface, inhibited inflammation, regulated macrophage polarization, and promoted bone formation. Ti-NW-Mg reduced the proliferation and adhesion of macrophages and decreased the release of inflammatory factors from macrophages. These results provide an essential experimental basis for the effect of Ti-NW-Mg on improving implant osteogenesis and increasing the implant success rate.

An immunological atomic force microscopy technique was used to recognize fibrinogen adsorption and functional activity on polyurethane biomaterial surfaces in the presence of other proteins. The amount of fibrinogen adsorbed on surfaces as recognized by an antifibrinogen polyclonal antibody when in competitive adsorption with human serum albumin (HSA) or human IgG was found to be related to the molar ratio of proteins. A significant decrease in fibrinogen adsorption was observed only when the fraction of smaller proteins reached a threshold value, dependent on smaller protein properties. The functional activity of fibrinogen was measured by a monoclonal antibody recognizing a region containing the dodecapeptide sequence located at the C-terminus of the &#x3b3;-chain, &#x3b3;-400-411. Results show that the presence of smaller proteins affected the conformational structure of fibrinogen and increased the availability of platelet binding sites in fibrinogen adsorbed on surfaces. Platelet adhesion was performed on polyurethane surfaces, which were competitively preadsorbed with fibrinogen and HSA. Platelet adhesion correlated well with the functional activity of fibrinogen, measured after competitive adsorption on surfaces. The work suggests that platelet adhesion is not necessarily determined by the amount of adsorbed fibrinogen but is related to the activity of fibrinogen as measured by the availability of the platelet binding sites in the fibrinogen, &#x3b3;-chain dodecapeptide.

The long-term stability of dental implants is significantly influenced by their resistance to foreign factors in the peri-implant epithelium (PIE). Despite this, enhancing the sealing properties at the implant-PIE interface continues to be an unmet clinical need. Ti-6Al-4V (Ti64) alloy has higher tensile strength and hardness than pure titanium. This study was to verify whether hydrothermal treatment of Ti64 alloy implants with distilled water (HT-DW) or calcium chloride (CaCl2) solution (HT-Ca) could improve the sealing of the PIE around Ti64 implants. The existence of calcium (Ca) on the surface of HT-Ca implants was confirmed using x-ray photoelectron spectroscopy and synchrotron-based x-ray absorption fine structure techniques. These data showed that the surface was oxidized, and Ca existed in the form of anhydrous CaCl2 and calcium titanate. Laminin-332 (Ln), which is an essential component of epithelial adhesion structures, was observed between all types of implants and the PIE, 4 weeks after implantation in rat maxillae. Ln distribution over the entire epithelial interface was similar for the HT-Ca implant and a natural tooth. Moreover, the HT-Ca implant inhibited foreign body penetration, which indicated stronger gingival sealing at the implant-PIE interface, compared with the untreated and HT-DW implants. We also investigated the attachment of mouse-derived gingival epithelial cells (GE1). GE1 adherence was stronger and Ln expression levels were higher for HT-Ca plates compared with the untreated and HT-DW plates. Our results demonstrate that hydrothermal treatment of Ti64 implants with CaCl2 solution facilitates the growth of an effective soft tissue seal around the implant.