In a remarkable leap forward for synthetic biology and targeted drug delivery, researchers have unveiled a pioneering method to remotely control the function of synthetic cells using magnetically activated spherical nucleic acids (SNAs). This breakthrough exploits the power of alternating magnetic fields (AMF) to precisely orchestrate the expression of functional proteins within synthetic cell constructs, thereby enabling the controlled release of molecular cargo from these artificial systems. The implications of this technology extend far beyond laboratory curiosity, opening up transformative possibilities for in vivo therapeutics and the next generation of smart, programmable biomaterials.
The study centers on the synthesis of an inactive DNA template coding for α-haemolysin (α-HL), a pore-forming protein renowned for its capacity to perforate lipid membranes. By carefully engineering this DNA template so that it remains dormant until triggered, the researchers achieved a remarkable level of spatiotemporal control over protein expression. α-HL’s role within the synthetic cell membrane is critical—upon expression and membrane insertion, it forms nanopores that serve as gateways for cargo molecules to exit the synthetic cell environment.
The production of these synthetic cells utilized giant unilamellar vesicles (GUVs), delicate yet robust lipid bilayers formed from egg phosphatidylcholine (egg-PC) through an inverted microemulsion technique. Each GUV encapsulated a cell-free protein synthesis (CFPS) system—PURExpress—alongside the magnetically responsive SNAs, the inactive α-HL DNA templates, and a fluorescent reporter molecule, 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG). This fluorescent glucose analog served as the model cargo, its fluorescence intensity providing a real-time readout of leakage through any formed membrane pores.
Rigorous control experiments underscored the precision and specificity of this magnetic activation system. Negative controls, containing the inactive α-HL template but no SNAs or lacking exposure to AMF, retained their 2-NBDG cargo over time, highlighting the tight suppression of protein expression in the absence of the magnetic stimulus. On the other hand, positive controls leveraging fully double-stranded α-HL templates demonstrated robust cargo release, affirming the system’s efficacy at expressing functional pores capable of inducing molecular efflux from the synthetic cells.
Upon exposure to a finely tuned AMF (30 mT at 103.4 kHz) for just ten minutes, synthetic cells encapsulating magnetically activated SNAs exhibited a dramatic decrease in 2-NBDG fluorescence. This loss directly corresponded with α-HL expression and the consequent formation of membrane pores, facilitating the model cargo’s exit. Fluorescence intensity measurements dropped significantly from initial levels, mirroring the positive control, a testament to the system’s efficiency in remotely regulating synthetic cell permeability in response to magnetic stimuli.
The underlying mechanism hinges on the magnetic activation’s ability to selectively melt DNA duplexes tethered to SNAs inside the synthetic cells. The thermal energy generated by the alternating magnetic field transiently opens the DNA hairpin structures, exposing template strands that kickstart CFPS within the vesicle. This level of control is revolutionary—it circumvents traditional chemical or optical inducers, which can be invasive or limited by penetration depth, offering a non-contact, highly penetrant method ideal for biomedical applications.
Moreover, the modular nature of the SNAs and DNA templates permits customization of synthetic cell responses, paving the way for programmable systems that can be tailored to express a variety of proteins on demand. This could translate into tailored release profiles for therapeutics or the dynamic modulation of synthetic cell functions in tissue engineering and regenerative medicine.
What makes this magnetic activation strategy especially alluring is its compatibility with biological environments. The non-ionizing magnetic fields employed here are known for their deep tissue penetration and minimal adverse effects, making this technology remarkably suited for in vivo scenarios. Imagine injectable synthetic cells that lie dormant until activated remotely by a clinician’s magnetic pulse, releasing drugs precisely when and where needed—this scenario moves closer to reality with this innovation.
Structurally, the synthetic cells’ lipid bilayers act as both protective barriers and controlled gating systems. α-HL inserts into these bilayers only after translation has been magnetically triggered, creating transient pores large enough for small molecules like 2-NBDG to pass while preserving vesicle integrity. This dynamic switching between sealed and permeable states under magnetic control provides a versatile platform for molecular delivery.
The study also tackled challenges associated with DNA template design. By employing lambda exonuclease to selectively remove one strand from phosphorylated primers, researchers crafted single-stranded DNA templates capable of forming inactive, double-stranded DNA that could be specifically activated by SNAs upon magnetic actuation. This precision biochemistry ensures minimal background expression and robust activation upon demand.
Additionally, fluorescence microscopy provided clear visualization of the system’s function. Synthetic cells exposed to AMF displayed a visible diminishment in 2-NBDG fluorescence within four hours post-exposure, while unexposed cells maintained cargo fluorescence, confirming that magnetic stimulation directly controlled pore formation and cargo release without non-specific leakage or unintended activation.
Beyond its impressive technical merit, this research sets a new paradigm in synthetic biology’s quest to engineer life-like systems. Incorporating magnetically responsive components into synthetic cells bridges the gap between physical stimuli and biological function, an interdisciplinary feat combining nanotechnology, molecular biology, and materials science.
Researchers anticipate that future iterations will focus on optimizing the sensitivity and response times, expanding the repertoire of proteins expressed, and integrating feedback mechanisms for more autonomous synthetic cells. Moreover, coupling this approach with targeting moieties could enable site-specific activation in multicellular environments, furthering the applicability of synthetic cells as intelligent drug delivery vehicles.
In conclusion, this study presents a powerful new tool for remotely manipulating synthetic cells with magnetic fields, steering protein expression and cargo release with unprecedented spatiotemporal precision. It opens avenues for next-gen therapeutics, smart materials, and synthetic biology applications where control over cellular mimetics at the nanoscale is crucial. As magnetic control technologies evolve, so too will their capacity to transform medicine, bringing the promise of on-demand, programmable cell-like systems closer to clinical reality.
The intersection of magnetics and synthetic biology heralded by this work underscores the creative potential unlocked when disciplines converge. By harnessing the inherent capabilities of nucleic acid nanotechnology within magnetically responsive frameworks, the authors have laid groundwork for a future where synthetic cells can be governed wirelessly—ushering in an era of remote-controlled biomolecular engineering.
This research not only provides proof of concept but firmly establishes magnetically activated SNAs as versatile components for synthetic biology. Its implications span fundamental science and translational applications, marking an epochal step toward responsive, intelligent synthetic cells that can be deployed safely and effectively in living organisms.
The field will undoubtedly watch closely as follow-up studies explore long-term stability, biocompatibility, and scaling of these magnetically controlled systems. Yet, even now, the promise is clear: magnetic fields may become the new language through which we converse with and command synthetic life.
Subject of Research: Magnetic activation of spherical nucleic acids to remotely control protein expression and cargo release in synthetic cells.
Article Title: Magnetic activation of spherical nucleic acids enables the remote control of synthetic cells.
Article References:
Parkes, E., Al Samad, A., Mazzotti, G. et al. Magnetic activation of spherical nucleic acids enables the remote control of synthetic cells. Nat. Chem. (2025). https://doi.org/10.1038/s41557-025-01909-6
Image Credits: AI Generated
Tags: alternating magnetic fields in biologygiant unilamellar vesicles synthesisin vivo therapeutics innovationslipid bilayer engineeringmagnetic activation of synthetic cellsnanopore technology in drug deliveryprogrammable synthetic biologyremote control of biomaterialsspatiotemporal control in protein expressionspherical nucleic acids technologytargeted drug delivery systemsα-haemolysin protein applications
