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Results for “Contact angle”

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9 recordsLinked to original sources

PubMed2026

Integrated experimental and bioinformatics analysis reveals ECM-integrin and redox signaling associated with PMMA/NiO nanocomposites for craniofacial applications.

BACKGROUND: Poly(methyl methacrylate) (PMMA) is widely used in dental and craniofacial applications; however, its clinical performance is limited by poor surface wettability, moderate mechanical strength, and restricted biological activity. Integrating nanomaterial engineering with computational biology offers an opportunity to better understand biomaterial-cell interactions and support the rational design of functional biomaterials. METHODS: Nickel oxide (NiO) nanoparticles were synthesized via chemical precipitation and incorporated into PMMA to fabricate nanocomposites. Physicochemical characterization included contact angle measurements, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Vickers hardness testing. Biocompatibility was evaluated using zebrafish embryo developmental assays. To explore biological processes potentially associated with biomaterial-cell interactions, bioinformatics analyses including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and STRING protein-protein interaction (PPI) network analyses were performed. RESULTS: Incorporation of NiO nanoparticles improved the surface and mechanical properties of PMMA, reducing the contact angle from 105.35° to 90.46° and increasing Vickers hardness compared with unmodified PMMA. Structural and morphological analyses confirmed successful synthesis and homogeneous nanoparticle incorporation. Zebrafish embryo studies demonstrated minimal developmental toxicity, supporting the biocompatibility of the nanocomposite. Bioinformatics analyses identified significant enrichment of pathways related to extracellular matrix organization, cell adhesion, focal adhesion, PI3K-Akt signaling, and oxidative stress regulation. Protein-protein interaction analysis revealed highly interconnected networks associated with ECM-integrin signaling and redox homeostasis, highlighting biological processes potentially associated with biomaterial-cell communication. CONCLUSIONS: PMMA/NiO nanocomposites exhibited improved physicochemical performance and favorable biocompatibility characteristics. The integration of experimental characterization with bioinformatics and network-based analyses provides a systems-level perspective on biomaterial-associated cellular processes and identifies ECM-integrin signaling and oxidative stress-related pathways as candidate biological processes for future experimental validation. These findings support the continued development of PMMA/NiO nanocomposites for oral and craniofacial biomedical applications.

Nanocomposites↗

PubMed2026

Transforming Curcuma longa leaf waste into cellulose scaffolds.

The constant dearth of transplantable tissues and organs in India required the development of substitute biomaterials for tissue engineering. Plant-based decellularized scaffolds have become attractive options because of their abundance, ethical acceptability, architectural diversity, and lower risks of zoonotic transmission. Curcuma longa leaves were investigated in this study as a possible source of cellulose-based scaffolding for use in biomedical applications. After cuticle removal, an immersion decellularization technique utilizing sodium dodecyl sulphate (SDS) and triton-X-100 was developed to successfully remove cellular and nuclear material while maintaining leaf parenchyma architecture. Histology, DAPI staining, scanning electron microscopy, and a notable decrease in leftover DNA content all demonstrated efficient decellularization. When contrasted with native leaves, the resultant decellularized C. longa leaf scaffolds showed significant increase in porosity, water vapor transmission rate and swelling percent, and significantly lower contact angle with an optimum surface roughness promoting cell adhesion. Mechanical test manifest higher tensile strength with decreased stiffness. Fourier transform infrared spectra of leaf scaffold reveals persistence of different components except cuticle but the intensity of different peaks was decreased. The leaf scaffolds showed superior hemocompatibility and excellent compatibility with Madin-Darby canine kidney cells (MDCK) which is demonstrated by cell attachment and proliferation. MTT assay of seeded scaffold showed significantly higher metabolically active cell. In vivo subcutaneous implantation of decellularized scaffolds showed host tissue incorporation, accumulation of collagen, and neovascularization. C. longa leaf scaffolds can be utilized as cost effective and sustainable biomaterials for soft tissue engineering and regenerative medicine.

Curcuma↗

PubMed2026

Alginate-based edible coating incorporating green tea extract for preserving postharvest quality and safety of white mushrooms (Agaricus bisporus).

This study aimed to evaluate the effects of a sodium alginate based edible coating incorporated with green tea extract (GTE) (Camellia sinensis) on the postharvest quality attributes and antimicrobial activity against Listeria monocytogenes in white mushrooms during refrigerated storage. The phenolic profile of GTE was characterized, and its minimum inhibitory concentration (MIC) against L. monocytogenes (1.6 mg/mL) was determined. Sodium alginate coatings, with (ALG-GTE) or without GTE (ALG) at MIC (1.6 mg/mL), were characterized (functional groups, solubility in water, moisture, thickness, water contact angle and color) for their chemical and physical properties. The effects of ALG-GTE coatings on quality parameters (firmness, weight loss, color, pH, sugars and organic acids), enzymatic activity [polyphenol oxidase (PPO), peroxidase (POD) and pectin methylesterase (PME)], antimicrobial activity against L. monocytogenes (5 log CFU/g), and surface characteristics (3D optical profilometry) were assessed in white mushrooms (Agaricus bisporus) during refrigerated storage (8 days, 4 ± 1 °C, 90-95% RH). The ALG-GTE coatings preserved sugar composition, particularly rhamnose, reduced organic acids accumulation and delayed weight and firmness loss, reduced color changes, and decreased PME activity in coated white mushrooms. L. monocytogenes counts decreased by 1.4 log CFU/g after 1 day, and no viable cells were detected after 2 days (< 1.5 log CFU/g) in ALG-GTE coated white mushrooms. In addition, ALG-GTE coated white mushrooms exhibited smoother surfaces than uncoated samples. These findings highlight the potential of ALG-GTE coatings as a sustainable alternative capable of improving the microbiological safety and delaying the postharvest changes in fresh mushrooms.

Agaricus↗

PubMed2024

Molecular basis for antibody recognition of multiple drug-peptide/MHC complexes.

The HapImmuneTM platform exploits covalent inhibitors as haptens for creating major histocompatibility complex (MHC)-presented tumor-specific neoantigens by design, combining targeted therapies with immunotherapy for the treatment of drug-resistant cancers. A HapImmune antibody, R023, recognizes multiple sotorasib-conjugated KRAS(G12C) peptides presented by different human leukocyte antigens (HLAs). This high specificity to sotorasib, coupled with broad HLA-binding capability, enables such antibodies, when reformatted as T cell engagers, to potently and selectively kill sotorasib-resistant KRAS(G12C) cancer cells expressing different HLAs upon sotorasib treatment. The loosening of HLA restriction could increase the patient population that can benefit from this therapeutic approach. To understand the molecular basis for its unconventional binding capability, we used single-particle cryogenic electron microscopy to determine the structures of R023 bound to multiple sotorasib-peptide conjugates presented by different HLAs. R023 forms a pocket for sotorasib between the VH and VL domains, binds HLAs in an unconventional, angled way, with VL making most contacts with them, and makes few contacts with the peptide moieties. This binding mode enables the antibody to accommodate different hapten-peptide conjugates and to adjust its conformation to different HLAs presenting hapten-peptides. Deep mutational scanning validated the structures and revealed distinct levels of mutation tolerance by sotorasib- and HLA-binding residues. Together, our structural information and sequence landscape analysis reveal key features for achieving MHC-restricted recognition of multiple hapten-peptide antigens, which will inform the development of next-generation therapeutic antibodies.

Humans↗

PubMed2026

Mapping Allosteric Communication in the Nucleosome with Conditional Activity.

The nucleosome core particle (NCP) regulates genome accessibility through dynamic allosteric communication between histone proteins and DNA. Building on the concept of conditional activity introduced by Lin (2016), we use molecular dynamics simulations and develop an open-source Python library, CONDACT (CONDitional ACTivity), to quantify time-resolved kinetic correlations in nucleosome systems. We analyze long-time simulations of the nucleosome core particle, including two different DNA sequences, the Widom-601 (PDB ID: 3LZ0) and ASP (alpha-satellite palindromic) sequences (PDB ID: 1KX5). By tracking dihedral angle transitions, we identify residues with high dynamical memory and map inter-residue communication pathways across histone subunits and DNA. Our analysis reveals kinetically connected domains involving post-translational modification sites, oncogenic mutation sites, and DNA contact regions, with dynamic coupling observed over distances up to 7.5 nm. These findings offer new insight into the long-range allosteric behavior of the nucleosome and its potential role in regulating chromatin accessibility. Quantifying this allosteric behavior potentially identifies targetable residues and domains for therapeutic intervention.

Nucleosomes↗

PubMed2025

Mapping Allosteric Communication in the Nucleosome with Conditional Activity.

The nucleosome core particle (NCP) regulates genome accessibility through dynamic allosteric communication between histone proteins and DNA. Building on the concept of conditional activity introduced by Lin (2016), we use molecular dynamics simulations and develop an open-source Python library, CONDACT (CONDitional ACTivity), to quantify time-resolved kinetic correlations in nucleosome systems. We analyze long-time simulations of the nucleosome core particle, including two different DNA sequences, the Widom-601 and ASP (alpha-satellite palindromic) sequences. By tracking dihedral angle transitions, we identify residues with high dynamical memory and map inter-residue communication pathways across histone subunits and DNA. Our analysis reveals kinetically connected domains involving post-translational modification sites, oncogenic mutation sites, and DNA contact regions, with dynamic coupling observed over distances up to 7.5 nm. These findings offer new insight into the long-range allosteric behavior of the nucleosome and its potential role in regulating chromatin accessibility. Quantifying this allosteric behavior potentially identifies targetable residues and domains for therapeutic intervention.

Journal Article↗

PubMed2026

[Effect of electroacupuncture combined with suspension exercise therapy on lower limb motor function in elderly patients with post-stroke spastic hemiplegia].

OBJECTIVE: To observe the efficacy of electroacupuncture (EA) combined with suspension exercise therapy in elderly patients with post-stroke spastic hemiplegia and its effect on lower limb motor function. METHODS: A total of 120 elderly patients with post-stroke spastic hemiplegia were enrolled. Using a 2×2 factorial design, all the patients were assigned to a group A (conventional treatment), a group B (conventional treatment combined with suspension exercise therapy), a group C (conventional treatment combined with EA at Jiaji [EX-B2] and limb acupoints), and a group D(conventional treatment combined with suspension exercise therapy and EA at Jiaji [EX-B2] and limb acupoints), with 30 patients in each group. The main acupoints were bilateral Jiaji (EX-B2) points at the C2-C7, T2-T12, L1-L5, and S1 segments. The adjunct acupoints included Jianyu (LI15), Binao (LI14), Huantiao (GB30), Chengfu (BL36), etc. on the affected side.Continuous wave was applied at a frequency of 100 Hz with a current intensity of 1.5-3.0 mA, and needles were retained for 30 min, once daily for 4 weeks. Before treatment and after 2 and 4 weeks of treatment, the modified Ashworth scale (MAS),Fugl-Meyer assessment (FMA), Berg balance scale (BBS), and Barthel index scores were evaluated in the four groups. Root mean square (RMS) values of surface electromyography (sEMG) of the erector spinae and rectus abdominis muscles on the affected side, as well as balance function indexes, including the mean pressure symmetry index (SI), contact area SI, ellipse area, and displacement distances of the center of pressure in the anteroposterior (AP) and mediolateral (ML) directions, were measured. Clinical efficacy was also compared among the four groups. RESULTS: After 2 and 4 weeks of treatment, MAS scores in all groups were lower than those before treatment (P<0.05), whereas FMA, BBS, and Barthel index scores were higher than those before treatment (P<0.05). After 4 weeks of treatment, MAS scores were lower than those after 2 weeks of treatment (P<0.05), whereas FMA, BBS, and Barthel index scores were higher than those after 2 weeks of treatment (P<0.05) in the four groups. At both 2 and 4 weeks after treatment, group D had lower MAS scores (P<0.05) and higher FMA,BBS, and Barthel index scores (P<0.05) than the other three groups. After 2 and 4 weeks of treatment, RMS values of sEMG of the erector spinae and rectus abdominis muscles on the affected side at all tested angles were higher than those before treatment in all groups (P<0.05), and the values after 4 weeks of treatment were higher than those after 2 weeks of treatment(P<0.05). At both 2 and 4 weeks after treatment, all these indexes in the group D were higher than those in the other three groups (P<0.05). After 2 and 4 weeks of treatment, the mean pressure SI, contact area SI and ellipse area of each group were lower than those before treatment (P<0.05). After 4 weeks of treatment, the mean pressure SI, contact area SI and ellipse area of each group were lower than those after 2 weeks of treatment (P<0.05). After 2 and 4 weeks of treatment, the AP displacement distances of groups A, C and D were lower than those before treatment (P<0.05), and after 4 weeks of treatment, the AP displacement distances of groups A, C and D were lower than those after 2 weeks of treatment (P<0.05);after 2 weeks of treatment, there was no statistically significant difference in AP displacement distance in the group B compared with before treatment (P>0.05), and after 4 weeks of treatment, the AP displacement distance of group B was lower than that before treatment (P<0.05). After 2 weeks of treatment, there was no statistically significant difference in ML displacement distance in group A compared with before treatment (P>0.05); after 4 weeks of treatment, the ML displacement distance of group A was lower than that before treatment (P<0.05). After 2 and 4 weeks of treatment, there was no statistically significant difference in ML displacement distance in the group B compared with that before treatment (P>0.05).After 2 and 4 weeks of treatment, the ML displacement distances of groups C and D were lower than those before treatment(P<0.05), and after 4 weeks of treatment, the ML displacement distances of groups C and D were lower than those after 2 weeks of treatment (P<0.05). At both 2 and 4 weeks after treatment, mean pressure SI, contact area SI, ellipse area, and AP and ML displacement distances in the group D were lower than those in the other three groups (P<0.05). Factorial analysis of variance showed that EA had the strongest main effect on FMA score (F=6.243, P<0.05), suspension exercise therapy had the strongest main effect on BBS score (F=6.292, P<0.05), and the interaction effect was most significant for MAS score (F=5.941, P<0.05), indicating that the combined therapy produced a greater synergistic effect on reducing muscle tone than on the other outcome measures. The total effective rate in the group D was 93.3% (28/30), which was higher than those in the group A (53.3% [16/30]), group B (56.7% [17/30]), and group C (66.7% [20/30], P<0.05). CONCLUSION: EA combined with suspension exercise therapy could effectively promote the recovery of lower limb function in elderly patients with post-stroke spastic hemiplegia, improve motor and balance functions, and enhance activities of daily living.

Humans↗

PubMed2025

MIA-Jet: Multi-scale Identification Algorithm of Chromatin Jets.

The mammalian genome is organized into large-scale chromosome territories, compartments, domains, and at the smallest scale, chromatin loops and stripes. The newest element is a chromatin jet, a diffused line perpendicular to the main diagonal in the Hi-C contact map, which was reported in quiescent mammalian lymphocytes supporting a two-sided symmetric cohesin loop extrusion model. A similar structure is observed in Repli-HiC data, where relatively thin and straight chromatin fountains indicate coupling of DNA replication forks. However, the precise biological implications of these jet-like structures are unknown due to the limitations in computational methods. We developed MIA-Jet, a multi-scale ridge detection algorithm that can accurately detect jets of variable lengths, widths, and angles. When tested on Hi-C, Repli-HiC, ChIA-PET, ChIA-Drop, and Micro-C data in mouse, human, roundworm, and zebrafish cells, MIA-Jet outperformed existing methods. In human cells, jets were enriched in cohesin loading sites and early replication initiation zones. Applying MIA-Jet to Hi-C data generated from protein-degraded cells revealed that jets are dependent on cohesin but not YY1, and jet signals are strengthened after depleting WAPL. We envision MIA-Jet to be broadly applicable to any 3D genome mapping data, thereby providing new insights into the functional roles of chromatin jets.

3D genome mapping↗

PubMed2026

A structural bridge between dengue virus tandem xrRNAs facilitates coordination of exonuclease resistance.

Orthoflavivirus RNA genomes resist host 5'-3' exoribonucleases to produce subgenomic flaviviral RNAs (sfRNAs). This resistance is conferred by exoribonuclease-resistant RNA (xrRNA) structures within the viral 3' untranslated region that often occur in tandem, and whose function can be coupled. In dengue virus serotype 2 (DENV2), this coupling results in changing patterns of sfRNA identity and abundance associated with the ability of the virus to adapt to host vs. vector infections. The physical basis of this coupling was unknown. Using a combination of virology, biochemistry, bioinformatics, structural biology, and biophysics, we explored the structural and sequence determinants of tandem xrRNA coupling in DENV2. We discovered that the spatial proximity, order, and structural integrity of the tandem xrRNAs are all important for coupling. Furthermore, an unpaired A-rich linker that lies between the two xrRNAs is essential in stabilizing a specific structure that correlates to coupling. This A-rich sequence likely forms tertiary contacts with an adjacent stem-loop structure to form a physical bridge between the two xrRNAs, a finding that is supported by a mid-resolution cryo-electron microscopy (cryo-EM) map of the DENV2 tandem xrRNAs. Disruption of the structure of this bridge by mutation changes the relative orientation or spacing between the tandem xrRNAs, which is correlated to their functional coupling. These findings help provide an explanation for the coupling between tandem xrRNAs, suggesting a new mechanistic hypothesis in which the two tandem xrRNAs can simultaneously encounter Xrn1.IMPORTANCEDengue virus (DENV) generates non-coding subgenomic flaviviral RNAs (sfRNAs) that affect several cellular pathways and are important for successful infection. These sfRNAs are formed by structured RNA elements in the viral genome called exoribonuclease-resistant RNAs (xrRNAs), which fold into a distinct three-dimensional topology to block degradation by host cell exoribonucleases and often occur in tandem. Specific patterns of sfRNAs made during infection are important for host vs. vector fitness, and in DENV2, this pattern depends on functional coupling between tandem xrRNAs. However, the source of this functional coupling was unknown. We determined that an unpaired A-rich linker between the tandem xrRNAs is necessary for creating a structural bridge between the tandem xrRNAs. This bridge appears to favor a specific orientation between the tandem xrRNAs that is correlated to coupling and therefore to the patterns and relative abundance of sfRNAs produced during infection.

Dengue Virus↗