Abstract Protein filaments, comprising microtubules, actin, and intermediate filaments, form the eukaryotic cytoskeleton through dynamic self-assembly governed by noncovalent interactions. These structures orchestrate cellular mechanics, architecture, and critical functions, including motility, division, and transport, through precise spatiotemporal regulation of their polymerization cycles. Recent advances in synthetic biology have established synthetic cytoskeletal systems using programmable building blocks that recapitulate or extend native filament functionalities, including controllable assembly and disassembly, directional cargo transport, and mechanochemical signal transduction. This review examines the evolutionary parallels and design divergences between natural and synthetic filaments, emphasizing how biological self-assembly principles can guide the engineering of programmable architectures. Comparative analysis identifies four interconnected design principles for next-generation synthetic filaments: tunable mechanical properties, reversible and energy-coupled nonequilibrium assembly, efficient directional transport or force generation, and feedback-controlled coupling between chemical signals and supramolecular organization. Despite substantial progress, synthetic systems still lag behind natural cytoskeletons in integrating these properties within a single autonomous platform. Bridging this gap will require the convergence of biophysics, synthetic biology, AI-guided molecular design, and automated Design–Build–Test–Learn workflows to connect molecular-scale engineering with adaptive cellular-scale function.
Abstract Coronaviruses, including SARS-CoV-2 and MERS-CoV, encode two large polyproteins, pp1a and pp1ab, that are primarily processed by highly conserved 3C-like proteases, yielding an array of structural and nonstructural proteins essential for viral replication. SARS-CoV-2 3CLpro is deemed to be a well-established and validated antiviral target. During cell entry, pathogenic coronaviruses, particularly the SARS-CoV-2 Omicron variants, utilize host cell cathepsins, including cathepsin L (CatL), and the endosomal pathway for successful infection. Furthermore, SARS-CoV-2 infection results in overexpression of CatL, which, in turn, intensifies SARS-CoV-2 infection. Consequently, CatL has emerged as a potential target for the development of COVID-19 therapeutics. We report herein a series of inhibitors that incorporate in their structure a nortropinone scaffold as a design element for probing and exploiting poorly explored regions of chemical space. The inhibitors were found to be noncytotoxic and to potently inhibit CatL and the 3CLpro of MERS-CoV and SARS-CoV-2. The IC50 values of compound 12 against human CatL, MERS-CoV 3CLpro, and SARS-CoV-2 3CLpro were determined to be 0.12 nM, 0.11 μM, and 0.38 μM, respectively. Furthermore, compound 12 was found to inhibit SARS-CoV-2 infection in vitro with an EC50 value of 0.09 ± 0.05 μM and a Safety Index >1100. High-resolution cocrystal structures with SARS-CoV-2 3CLpro and MERS-CoV 3CLpro confirmed the mechanism of action of the compounds, illuminated the molecular determinants associated with binding, and informed the optimization of the inhibitors.
Abstract Copaifera multijuga Hayne oleoresin is a natural product containing bioactive terpenoid compounds that has attracted interest for pharmaceutical and topical applications. However, its incorporation into topical formulations may be limited by its physicochemical characteristics and potential cellular effects. This study aimed to develop and characterize a niosomal hydrogel containing C. multijuga oleoresin, with particular emphasis on its physicochemical, structural, rheological, and cytotoxicity properties. Niosomes composed of Tween 80 and cholesterol were developed using a design of experiments and evaluated for mean vesicle size and polydispersity index over 60 days. The most promising formulation was further characterized for ζ-potential and encapsulation efficiency, and a niosomal hydrogel containing 100 mg of Tween 80, 10 mg of cholesterol, and 300 mg of oleoresin was prepared. The formulations were evaluated for spreadability, rheological behavior, nuclear magnetic resonance relaxometry, morphology, and cytotoxicity in human fibroblasts and keratinocytes. Niosome 1 was selected for incorporation into the hydrogel, which exhibited suitable organoleptic characteristics and a pH of 6.78. The niosomal hydrogel showed a spreadability factor of 16.57 ± 0.23 mm2/g and pseudoplastic non-Newtonian behavior. Nuclear magnetic resonance relaxometry indicated an increase in T2H relaxation time, suggesting greater molecular mobility compared with the blank hydrogel. Morphological analysis showed that the vesicles remained predominantly individualized after incorporation into the hydrogel, without evident structural disruption. Free oleoresin reduced cellular metabolic activity concentration-dependently. Niosomal encapsulation attenuated this effect, particularly in fibroblasts, while the hydrogel showed concentration-dependent effects on cellular metabolic activity. Overall, the findings demonstrate the feasibility of incorporating C. multijuga oleoresin into a niosomal hydrogel and provide physicochemical, structural, rheological, and cytotoxicity data supporting its potential as a topical delivery system.
Abstract Cannabidiol (CBD) is a highly lipophilic phytocannabinoid with therapeutic potential, but its poor aqueous solubility, chemical instability, limited bioavailability, and first-pass metabolism restrict its pharmaceutical performance. An expanding range of nano- and microstructured delivery systems has been developed to rationally engineer CBD transport, stability, release, and biological activity. This review critically evaluates evidence from 55 studies, examining recent advances in CBD delivery platforms, with emphasis on the relationship between fabrication methodology, carrier architecture, molecular encapsulation mechanisms, physicochemical properties, and therapeutic function. Polymeric micelles and nanoparticles, lipid-based nanocarriers, biopolymer matrices, extracellular vesicles, inorganic–organic hybrids, nanoemulsions, liposomal systems, and Pickering emulsions are analyzed in relation to their capacity to improve CBD solubilization, protect against degradation, modulate release kinetics, enhance biodistribution, and support target-enhanced or localized delivery potential. Particular attention is given to the mechanistic contributions of hydrophobic partitioning, hydrogen bonding, electrostatic interactions, physical entrapment, and matrix diffusion to CBD encapsulation and release. Advanced fabrication technologies, including microfluidic nanoprecipitation, flash nanoprecipitation, high-pressure homogenization, microwave-assisted synthesis, and hybrid assembly strategies, further demonstrate progress from empirical formulation toward rational engineering of delivery systems. Across neurological, oncological, inflammatory, dermatological, and autoimmune applications, these platforms show potential to enhance bioavailability and therapeutic performance. Nevertheless, challenges remain regarding formulation standardization, long-term safety, scale-up, reproducibility, regulatory harmonization, and clinical translation. Overall, the field is moving toward structure–function-guided CBD delivery systems in which molecular interactions, carrier architecture, manufacturing technology, and biological barriers are deliberately integrated. This paradigm shift positions CBD nanomedicine as a promising platform for next-generation, application-specific therapeutic delivery.
Abstract Chronic pain is a persistent sensory and emotional condition that extends beyond tissue healing and imposes a substantial clinical and socioeconomic burden worldwide. It includes nociplastic, neuropathic, and inflammatory pain states that all lead to maladaptive peripheral and central sensitization, making diagnosis more challenging while reducing the overall effectiveness of long-term treatment. Many patients experience inadequate pain relief with currently available analgesic drugs, including nonsteroidal anti-inflammatory medications, opioids, antidepressants, and anticonvulsants, owing to their limited efficacy, development of tolerance, and severe adverse effects. There is increasing evidence that, ion-channel modulation serves an important role in the onset and maintenance of chronic pain. Membrane excitability, neurotransmitter release, and synaptic plasticity controlled by voltage-gated sodium (Nav), voltage-gated calcium (Cav), and transient receptor potential (TRP) channels are all considered essential components of nociceptive signaling. Pathological remodeling of Na+ channels (Nav1.7, Nav1.8, Nav1.9, and Nav1.3) has been associated with ectopic firing and nociceptor hyperexcitability in a variety of preclinical and clinical investigations, whereas Ca+ channels (Cav2.2, Cav3.x, and α2δ subunits) have been linked to enhanced central sensitization and calcium-dependent transmission. Interactions among these channel families form feed-forward mechanisms that sustain pain signaling across peripheral and central circuits. This review highlights Nav, Cav, and TRP channel crosstalk and their differential involvement across pain phenotypes and disease stages, while discussing emerging therapeutic strategies, including isoform-selective and state-dependent modulators, peripheral restriction, combination therapies, and targeted delivery systems. Integrating these mechanistic insights with ion-channel profiling and phenotype- and tissue-selective modulation may enable more rational target selection, improve therapeutic precision, and facilitate the development of selective, durable, mechanism-based treatments for chronic pain.
