Biointerphases最新文献

The special structure of eyes and the existence of various physiological barriers make ocular drug delivery one of the most difficult problems in the pharmaceutical field. Considering the problems of patient compliance, local administration remains the preferred method of drug administration in the anterior part of eyes. However, local administration suffers from poor bioavailability, need for frequent administration, and systemic toxicity. Administration in the posterior part of the eye is more difficult, and intravitreal injection is often used. But intravitreal injection faces the problems of poor patient compliance and likely side effects after multiple injections. The development of nanocarrier technology provides an effective way to solve these problems. Among them, liposomes, as the most widely used carrier in clinical application, have the characteristics of amphiphilic nanostructure, easy surface modification, extended release time, good biocompatibility, etc. The liposomes are expected to overcome obstacles and effectively deliver drugs to the target site to improve ocular drug bioavailability. This review summarized the various controllable properties of liposomes for ocular delivery as well as the application and research progress of liposomes in various ocular diseases. In addition, we summarized the physiological barriers and routes of administration contained in eyes, as well as the prospects of liposomes in the treatment of ocular diseases.

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 = 0.027). Patient satisfaction rates were markedly higher in the improved PEEK cohort (P < 0.05). Although the medical expenses for the enhanced PEEK group were greater (¥ 144 600 ± 21 200 vs ¥ 127 400 ± 20 100, P < 0.05), there were no notable differences in cerebral blood flow perfusion or survival time between the two groups (P > 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.

Bletilla striata polysaccharide, also known as Bletilla gum, is a water-soluble polymeric viscous polysaccharide with antimicrobial and coagulation-promoting activities. This study used Bletilla striata polysaccharide as the base material and crosslinked it with an electroactive carrier material to prepare a hydrogel with both conductivity and bioactivity. Specifically, hydroxypropyl chitosan with good bioactivity was used as a cross-linking agent. Through Schiff base reaction, oxidized hyaluronic acid grafted with aniline tetramer copolymer and oxidized Bletilla striata polysaccharide were crosslinked to prepare conductive hydrogels, and their properties were characterized. Comparative results indicate that the oxidized Bletilla striata polysaccharide-hyaluronic acid conductive hydrogel (HP/OB-OT4) prepared with 20% grafted conductive polymer aniline tetramer content exhibits good conductivity, with an electrical conductivity reaching 0.32 ± 0.013 mS/cm, meeting the requirements for microcurrent stimulation. It also shows a degradation rate of 58.46 ± 1.96% and possesses good antibacterial properties and biocompatibility, demonstrating potential for application in biomedical material fields such as wound dressings.

Despite the complexity of the photosynthetic system, a simple explanation is proposed for the photon-flux density dependence of P-I curves (biomass production rate versus flux density) and electron transfer rate curves (delivery transfer rate of excited electrons from PS II, the first stage of the photosynthetic process, to the second stage, PS I, versus flux density). It is shown that the photon-flux density dependence of these two entities is a direct consequence of the stochastic nature of photon arrival times on the chlorophyll antenna of PS II, the existence of a rate-limiting time scale of about 10 ms in the operation of the photosystem, and the magnitude of the average photon absorption cross-sectional area of the chlorophyll antennae.

Coprecipitation biomineralization was induced using nondialyzed and dialyzed aqueous wheat bran extracts as scaffolds, to which zinc (Zn) was added in a 0%-15% concentration range. Spherical particles of brushite were precipitated up to 3% Zn concentration in the nondialyzed extracts. At 5% and 10% Zn, spherical or spheroidal brushite particles were precipitated, but the internal microstructure changed from stacked plates to laid parallel strands; a secondary weddellite phase was formed. Brushite with 0.018% Zn content was formed even without external additions due to the natural presence of Zn in the nondialyzed extracts. The Zn content of doped brushite particles was between 0.74% and 1% by weight for the 3%-10% added Zn range. Higher concentrations of Zn inhibited crystal growth. In dialyzed extracts, brushite spherical particles were formed only without added external Zn. However, crystal morphology was very similar, and the radial arrangement was maintained. Amorphous material with varied elemental composition precipitated only when Zn was added to the dialyzed extracts. Lattice parameters of brushite were close to those found in the literature, with minor variations for b and c. The results show the evidence of the role of Zn in the spherical morphology of brushite.

Ligand binding to a cell receptor often insufficiently triggers cellular immune responses. Receptor clustering through cross-linking occurs when a ligand binds to two or more receptors, amplifying cellular responses. This is required in certain monoclonal antibodies (mAbs), including effector mechanism activation [binding to fragment crystallizable receptors (FcRs)] or acting as agonists for therapeutic signaling. Therefore, immobilized immunoglobulin immunoassays were developed for efficient diagnostic and therapeutic approaches. The immobilized mAb density and orientation influence the sensitivity and accuracy of these assays. Limited evidence shows that different epitope motifs with the same target mAbs affect immobilized density and orientation in the solid-phase state. Here, we developed a series of fully humanized antidendritic cell immunoreceptor (DCIR) mAbs with different epitopes but the same Fc region. Immobilized anti-DCIR mAbs trigger the effector response from FcR through the Fc region and induce inhibitory pathways from the DCIR intracellular immunoreceptor tyrosine-based inhibitory motif through the fragment variable (Fv) region. In the immobilized immunoglobulin immunoassay, the isoelectric points (pI) of the DCIR mAb Fv region, not the total pI, significantly correlate to the surface density and orientation of immobilized mAbs on negatively charged plates. Cytokine production and protein phosphorylation in human monocytes were affected by vary binding abilities of immobilized mAbs to the plate. Methods, such as increasing hydrophobicity or ionic interactions, have improved the surface density and consistent orientation of immobilized anti-DCIR mAbs. Our study highlights the critical relationship between the net charge of the antibody Fv region and its immobilization potential in the solid-phase state.

Cell-penetrating peptides are efficient tools for intracellular delivery of a variety of cargoes. In this study, we explored the effect of chain length, side chain chemistry, and the locations of conjugated molecules on the interaction between iron-chelating peptides and a mitochondrial-mimicking membrane. We report that a longer chain length enhanced peptide/membrane interactions, and conjugation at the N-terminus lowered the free-energy barrier for peptide translocation across the membrane. Peptides containing Phe side chains and those containing modified Phe (cyclohexane) side chains showed comparable peptide/membrane energetics and translocation energy barriers. Using steered molecular dynamics (SMD) simulations, we further probed the mechanistic details of translocation of each N-terminated peptide across the membrane and compared their metastable states. At a higher steering velocity, the peptide adopted a compact structure due to frequent π-π interactions among conjugated molecules, but at lower steering velocities, each N-terminated peptide adopted an extended structure. This structure allowed cationic residues to maximize their interactions with phosphate headgroups in the mitomembrane. The hydrophobic residues also formed interactions with the lipid acyl tails, facilitating the passage of peptides across the membrane with decreased free energy barriers. Our results highlight the significance of peptide chain length and conjugation in facilitating peptide transport across the membrane.

The growing threat of antibiotic-resistant bacteria necessitates the development of alternative antimicrobial agents. Gallium oxyhydroxide (GaOOH) is a promising candidate, though its direct antibacterial efficacy is unexplored. This study provides the first direct evidence of GaOOH microparticles exhibiting cytotoxic effects against both Gram-positive Staphylococcus aureus (S.aureus) and Gram-negative Escherichia coli (E. coli). Orthorhombic GaOOH particles were synthesized hydrothermally, with their morphology influenced by the pH of the synthesis process, as confirmed by scanning electron microscopy and x-ray diffraction analysis. Antibacterial assays revealed that cytotoxicity against E. coli increases with a higher synthesis pH, a trend we demonstrate to be associated with the enhanced defect density in particles, as supported by photoluminescence spectra and FTIR analysis. The study underscores the significant influence of synthesis conditions on the morphology and crystallinity of the resulting GaOOH microparticles, highlighting the influence of surface characteristics on antibacterial agents.

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.

Self-healing cement takes advantage of microbial induced carbonate precipitation (MICP), a meritorious biological process, to achieve automatic healing of cement cracks. In this study, two beneficial factors, optimization of the bacteria culture medium and encapsulation of bacterial spores, were used to improve the MICP efficiency of Sporosarcina pasteurii in self-healing cement. On the one hand, in medium optimization, we compared the growth of Sporosarcina pasteurii fed with two generally used nitrogen sources, e.g., urea and ammonium chloride, and found that ammonium chloride can promote biomineralization more efficiently than urea. It was also confirmed that nickel (0.1 mg/l) and manganese ions (10 mg/l) benefit the MICP process through enhancement of urease activity and promotion of spore production. On the other hand, spores encapsulated in sodium alginate-gelatin gel beads prepared by using a flow nozzle device can have excellent swelling performance triggered by water. As an application demonstration, self-healing of cement cracks with consideration of the above beneficial factors was successfully verified without substantial influence on the cement compressive strength.