Biophysica, Volume 6, Issue 1 (February 2026) – 10 articles

Cancer is one of the leading causes of mortality worldwide, with breast and colon cancers being among the most common neoplasms in men and women, respectively. Despite significant advancements in treatment, there is a pressing need to enhance specificity and reduce systemic side effects. Importantly, a distinctive feature of cancer cells is their acidic extracellular environment, which profoundly influences cancer progression. In this study, we evaluated the anticancer activity of a pH-sensitive nanocomposite based on silver nanoparticles and pegylated carboxymethyl chitosan (AgNPs-CMC-PEG) in breast cancer (MCF-7) and colon cancer (HCT 116) cell lines. To achieve this, we synthesized and characterized the nanocomposite using UV-Vis spectroscopy, Dynamic Light Scattering (DLS), Fourier-Transform Infrared Spectroscopy (FT-IR), and Scanning Electron Microscopy (STEM-in-SEM). Furthermore, we assessed cytotoxic effects, apoptosis, and reactive oxygen species (ROS) generation using MTT, DAPI, and H2DCFDA assays. Additionally, we analyzed the expression of DNA methyltransferases (DNMT3a) and histone acetyltransferases (MYST4, GCN5) at the mRNA level using RT-qPCR, along with the acetylation and methylation of H3K9ac and H3K9me2 through Western blot analysis. The synthesized nanocomposite demonstrated an average hydrodynamic diameter of approximately 175.4 nm. In contrast, STEM-in-SEM analyses revealed well-dispersed nanoparticles with an average core size of about 14 nm. Additionally, Fourier-transform infrared (FTIR) spectroscopy verified the successful surface functionalization of the nanocomposite with polyethylene glycol (PEG), indicating effective conjugation and structural stability. The nanocomposite exhibited a pH and concentration dependent cytotoxic effect, with enhanced activity observed at an acidic pH 6.5 and at concentrations of 150 µg/ml, 75 µg/ml, and 37.5 µg/ml for both cell lines. Notably, the nanocomposite preferentially induced apoptosis accompanied by ROS generation. Moreover, expression analysis revealed a decrease in H3K9me2 and H3K9ac in both cell lines, with a more pronounced effect in MCF-7 at an acidic pH. Furthermore, the expression of DNMT3a at the mRNA level significantly decreased, particularly at acidic pH. Regarding histone acetyltransferases, GCN5 expression decreased in the HCT 116 line, while MYST4 expression increased in the MCF-7 line. These findings demonstrate that the AgNPs-CMC-PEG nanocomposite has therapeutic potential as a pH-responsive nanocomposite, capable of inducing significant cytotoxic effects and altering epigenetic markers, particularly under the acidic conditions of the tumor microenvironment. Overall, this study highlights the advantages of utilizing pH-sensitive materials in cancer therapy, paving the way for more effective and targeted treatment strategies. Full article

Fish collagen is derived from processing residues of marine and freshwater fish (such as fish skin, scales, and bones), primarily composed of amino acids including glycine, proline, and hydroxyproline. It functions include maintaining tissue integrity and promoting cell proliferation and repair. Extraction methods primarily include acid, alkali, enzymatic, and physical approaches, while purification techniques involve gel filtration chromatography, ultrafiltration, and precipitation. Furthermore, thermal instability, insufficient mechanical strength, immunological concerns, and biocompatibility limitations restrict its application across various fields. This review summarizes the composition, extraction, purification, and existing challenges of fish collagen, proposing improvement strategies. It systematically addresses issues related to fish collagen's biocompatibility, filling a gap in the literature. However, effectively enhancing its biocompatibility remains an urgent priority. Approaches such as nanotechnology and composite material development offer novel avenues for improving biocompatibility and future applications. Full article

Mitochondria serve as central hubs of cellular metabolism, integrating catabolic and anabolic pathways through the controlled exchange of metabolites across their membranes. Although mitochondrial transport of several metabolites has been well documented, the mechanisms underlying the trafficking of fumarate, glutamine, and phosphoenolpyruvate as well as the role of the mitochondrial pyruvate kinase remain insufficiently represented in modern biochemistry textbooks. Here, we revisit the biochemical evidence supporting specific transport activities for these metabolites, discuss their physiological roles in major metabolic pathways, and highlight how foundational experimental studies have been overlooked in contemporary literature. Re-examining these mechanisms provides new insight into the dynamic interplay between mitochondrial function, cytosolic metabolism, and overall cellular homeostasis. Full article

Thrombosis is a cardiovascular disease characterized by the pathological formation of a fibrin clot in blood vessels. Currently available fibrinolytic enzymes have some limitations, including severe side effects, high cost, short half-life, and low fibrin specificity. Proteins from microalgae and cyanobacteria have various biological effects and are emerging as promising sources for fibrinolytic enzymes. In this study, bioinformatics tools were used to evaluate the intrinsic disorder predisposition of microalgal fibrinolytic proteins, their capability to undergo liquid–liquid phase separation (LLPS), and the presence of disorder-based functional regions, and short linear motifs (SLiMs). Analysis revealed that these proteins are predominantly hydrophilic and exhibit acidic (pI 3.96–6.49) or basic (pI 8.05–11.0) isoelectric points. Most of them are expected to be moderately (61.4%) or highly disordered proteins (6.8%) and associated with LLPS, with nine proteins being predicted to behave as droplet drivers (i.e., being capable of spontaneous LLPS), and twenty-five proteins being expected to be droplet clients. These observations suggest that LLPS may be related to the regulation of the functionality of microalgal fibrinolytic proteins. The majority of these proteins belong to the blood coagulation inhibitor (disintegrin) 1 hit superfamily, which can inhibit fibrinogen binding to integrin receptors, preventing platelet aggregation. Furthermore, the SLiM-centered analysis indicated that the main motifs found in these proteins are MOD_GlcNHglycan and CLV_PCSK_SKI1_1, which can also play different roles in thrombolytic activity. Finally, Fisher and conservation analysis indicated that CLV_NRD_NRD_1, CLV_PCSK_FUR_1, CLV_PCSK_PC7_1, and MOD_Cter_Amidation motifs are enriched in intrinsically disordered regions (IDRs) of these proteins, showing significant conservation and suggesting compatibility with proteolytic activation and post-translational processing. These data provide important information regarding microalgal proteins with potential thrombolytic effects, which can be realized through protein–protein interactions mediated by SLiMs present in intrinsically disordered regions (IDRs). Additional analyses should be conducted to confirm these observations using experimental in vitro and in vivo approaches. Full article

ORF8 is the second most mutated protein in SARS-CoV-2. It can form oligomers such as trimers and can bind to the IL-17RA/RC receptor. To understand the possible role of ORF8 in SARS-CoV-2, the first step of this study involved predicting the ORF8 trimer structure and the complex structure of the ORF8 monomer bound to the IL-17RA receptor using docking and molecular dynamics simulation methods. It was found that ORF8 molecules bound to the central ORF8 molecule through covalent and noncovalent interactions exhibit similar RMSD and RMSF values as the central ORF8 molecule and form a similar buried surface area, but display different numbers of hydrogen bonds and varying dynamic correlations. Additionally, trimer formation increases the dynamic correlation of the noncovalently bound ORF8 unit. ORF8 can bind with the IL-17RA receptor stably. Regions on ORF8, including C25–I47, L60–S67, T80–C90, and S103–E110, and regions on IL-17RA, including L1–H63 and D122–M165, are involved in the binding interface of the complex. ORF8 becomes less rigid when bound to IL-17RA than in its monomer, dimer, and trimer forms. Based on dihedral angle correlation predictions, binding of ORF8 to IL-17RA reduces internal correlations within ORF8 while strengthening correlations within IL-17RA. The G50–T80 region of ORF8 appears to be critical for interaction with IL-17RA, and the L1–V150 region of IL-17RA should be critical for its dynamics once bound to ORF8. These results help elucidate the structure and dynamics of ORF8 in SARS-CoV-2. Full article

Here we present a retrospective, integrative review of the approaches and discoveries of our “collaboratory”, a meta-laboratory comprising cross-disciplinary collaborations across laboratories at fourteen different universities and clinics in seven different countries with shared lead investigators. By tying together insights from four decades of research and discovery, applied across cell types, as well as different tissues, organ systems, and organisms, we have aimed to elucidate the interplay between organisms’ movement and the physiology of their tissues, organs, and organ systems’ resident cells. We highlight the potential of increasing imaging and computing power, as well as machine learning/artificial intelligence approaches, to delineate the Laws of Biology. Codifying these laws will provide a foundation for the future, to promote not only the discovery of underpinning mechanisms but also the sustainability of our natural resources, from our brains to our bones, which serve as veritable “hard drives”, physically rendering a lifetime of cellular experiences and millennia of evolution. Full article

The glomerular filtration barrier poses a significant challenge for circulating proteins, with molecules below ~60–70 kDa facing rapid renal clearance. Endogenous proteins have evolved sophisticated evasion mechanisms including oligomerization, carrier binding, electrostatic repulsion, and FcRn-mediated recycling. Understanding these natural strategies provides blueprints for engineering therapeutic proteins with improved pharmacokinetics. This review examines how endogenous proteins resist filtration, evaluates their application in protein engineering, and discusses clinical translation including established technologies (PEGylation, Fc-fusion) and emerging strategies (albumin-binding domains, glycoengineering). We address critical challenges of balancing half-life extension with tissue penetration, biological activity, and immunogenicity—essential considerations for the rational design of next-generation therapeutics with optimized dosing and enhanced efficacy. Full article

Cedrus atlantica wood tar (CAWT) is traditionally used as a medicinal product, especially in low- and middle-income countries. Despite its traditional use, scientific support for its efficacy remains limited. This study evaluated the biological properties of CAWT using an integrated approach that combined qualitative and quantitative phytochemical analysis, disc diffusion and microdilution tests for antimicrobial assays (disc diffusion and microdilution), antioxidant activity (DPPH and ferric-reducing power assays), in silico ADMET/toxicity, docking, and MD/MMGBSA and provided a balanced comparison with reference antioxidants. This study demonstrated that CAWT is rich in secondary metabolites linked to biological activity, including polyphenols (307.39 ± 58.45 mg GAE/g), tannins (124.42 ± 6.14 mg TAE/g), and flavonoids (15.62 ± 2.53 mg QE/g). For free radical scavenging, CAWT inhibited DPPH with an IC50 of 19.781 ± 2.51 µg/mL and showed ferric-reducing activity with an IC50 of 83.7 ± 2.88 µg/mL for its antimicrobial activity against Pseudomonas aeruginosa; inhibition zones reached 35.66 ± 0.58 mm. In silico analysis, Swiss ADMET and pkCSM predicted ≥94% intestinal absorption, no cytochrome P450 liabilities, and low acute toxicity for six dominant terpenoids. Docking pinpointed trans-cadina-1(6),4-diene and α/β-himachalene as high-affinity ligands of LasR and gyrase B (ΔG ≈ −8 kcal mol⁻¹). A 100 ns GROMACS run confirmed stable hydrophobic locking of the lead LasR complex (RMSD 0.22 nm), while MM/GBSA calculated a dispersion-dominated binding free energy of −37 kcal mol⁻¹. Overall, CAWT showed in vitro antioxidant activity (DPPH and ferric-reducing assays) and inhibitory effects in disc diffusion assays, while in silico predictions for major terpenoids suggested favorable oral absorption and low acute toxicity. However, chemical composition analysis and bio-guided fractionation are necessary to confirm the antimicrobial activity and to validate the compounds responsible for the observed effects. Full article

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by memory loss, cognitive decline, and oxidative stress-driven neuronal damage. Catalase, a key antioxidant enzyme, plays a vital role in decomposing hydrogen peroxide (H₂O₂) into water and oxygen, thereby protecting neurons from reactive oxygen species (ROS)-mediated toxicity. In AD, the catalase function is compromised due to reduced enzymatic activity and aggregation, which not only diminishes its protective role but also contributes to amyloid plaque formation through catalase-Aβ co-oligomers. Hence, therapeutic strategies aimed at simultaneously preventing catalase aggregation and enhancing its enzymatic function are of great interest. In this study, we screened twelve naturally occurring metabolites for their ability to modulate catalase aggregation and activity. Among these, dimethylglycine (DMG) emerged as the most potent candidate. DMG significantly inhibited thermally induced aggregation of catalase and markedly enhanced its enzymatic activity in a concentration-dependent manner. Biophysical analyses revealed that DMG stabilizes catalase by promoting its native folded conformation, as evidenced by increased melting temperature (T_m), higher Gibbs free energy of unfolding (ΔG°), and reduced exposure of hydrophobic residues. TEM imaging and Thioflavin T assays further confirmed that DMG prevented amyloid-like fibril formation. Molecular docking and dynamics simulations indicated that DMG binds to an allosteric site on catalase, providing a structural basis for its dual role in stabilization and activation. These findings highlight DMG as a promising therapeutic molecule for restoring catalase function and mitigating oxidative stress in AD. By maintaining catalase stability and activity, DMG offers potential for slowing AD progression. Full article

Making advancements in Quantitative Structure-Activity Relationship (QSAR) modeling is crucial for predicting biological activities in new compounds. Traditional 2D-QSAR and 3D-QSAR methods often face challenges in terms of computational efficiency and predictive accuracy. This study introduces a machine learning approach using 3D Discrete Tchebichef Moments (3D-DTM) to address these issues. The 3D-DTM method offers efficient computation, robust descriptor generation, and improved interpretability, making it a promising alternative to conventional QSAR techniques. By capturing global 3D shape information, this method provides better representation of molecular interactions essential for biological activities. We applied the 3D-DTM model to a dataset of 46 molecules derived from the Dihydrophenanthrene scaffold, screened against the enzymatic activity of 3-chymotrypsin-like protease, a key antiviral target. Principal Component Analysis and k-means clustering refined descriptors, followed by stepwise Multiple Linear Regression (step-MLR), Partial Least Squares Regression (PLS-R), and Feed-Forward Neural Network (FFNN) techniques for 3DTMs-QSAR model development. The results showed high correlation and predictive accuracy, with significant validation from internal and external tests. The step-MLR model emerged as the optimal method due to its balance of predictive power and simplicity. Validation through y-Randomization and applicability domain analysis confirmed the model’s robustness. Virtual screening of 100 novel compounds identified 32 with improved pIC₅₀ values. This study highlights the potential of 3D-DTMs in QSAR modeling, providing a scalable and reliable tool for computational chemistry and drug discovery. A user-friendly software tool was also developed to facilitate 3D-DTM extraction from input 3D molecular images. Full article