In the ever-evolving quest to advance agricultural biotechnology, a breakthrough innovation from Iowa State University researchers is poised to revolutionize the way plant genetic modifications are carried out. For over three decades, plant scientists have relied on a technology known as the “gene gun” to deliver genetic material into plant cells, a process crucial to developing crops with improved yield, disease resistance, and adaptability to environmental stressors. However, this technology has long been hampered by inefficiencies, inconsistent results, and physical damage to plant tissues, challenges that limited its transformative potential—until now.
Since its inception in 1988, the gene gun has been the standard tool for “biolistic” delivery, wherein microscopic gold or tungsten particles coated with DNA are propelled at high velocity into plant cells, penetrate tough cellular walls, and enable the insertion of desirable genes. Despite its pioneering role in plant transformation efforts, gene guns have suffered from unpredictable particle trajectories and high-velocity impacts that caused excessive tissue damage and suboptimal gene integration. For years, these limitations were accepted as unavoidable, leaving researchers to work around the shortcomings rather than address their root causes.
That paradigm shifted dramatically when Shan Jiang, an associate professor in Iowa State’s Materials Science and Engineering department, applied his expertise in fluid dynamics and materials engineering to investigate the inner workings of gene gun devices. Fascinated by the overlooked intersection of materials science and plant biology, Jiang brought new perspectives from his experience as a post-doctoral researcher in the renowned Langer Lab at MIT—where pioneering mRNA delivery for medical applications inspired him to rethink gene delivery in agriculture.
Collaborating closely with Kan Wang, a distinguished professor of agronomy and crop bioengineering at Iowa State, Jiang initiated a multi-disciplinary research effort aimed at dissecting and improving the fundamental mechanics of gene gun operation. They hypothesized that the internal airflow dynamics within gene guns, previously unexamined with modern tools, could be a critical bottleneck limiting performance. Using advanced computational fluid dynamics modeling, the team revealed for the first time that the narrow internal barrel of the conventional gene gun created a restrictive choke point. This bottleneck caused particles to scatter unevenly, slowed their velocity, and drastically reduced the number of particles effectively delivered to plant cells.
Armed with this insight, the researchers designed a novel internal component they dubbed the “Flow Guiding Barrel.” This carefully engineered barrel optimized the airflow to channel nearly 100% of the particles directly toward target cells in stark contrast to the mere 21% efficiency of conventional guns. Drastic improvements followed, with experiments showing a 22-fold enhancement in transient transfection efficiency in onion cells and a 17-fold increase in viral infection rates in maize seedlings. Notably, the device doubled the success rates of CRISPR-mediated genome editing in wheat, demonstrating broad applicability across plant systems.
The significance of the Flow Guiding Barrel transcends raw efficiency metrics. It mitigates the collateral tissue damage that has plagued high-velocity gene gun applications by moderating particle velocity distribution and improving penetration patterns. As a result, fewer plant cells are destroyed, thereby improving regeneration success and enabling more precise genome editing outcomes. Moreover, the innovation reduces the frequency of fragmented or multiple gene insertions, a longstanding challenge that introduced unpredictability in trait expression and hindered downstream breeding and research efforts.
These transformative advancements herald far-reaching implications for agriculture and global food security. Improved transformation efficiency accelerates breeding programs, dramatically shortens the time from lab to field, and reduces costs associated with developing new crop varieties. With projections of a 10- to 20-fold increase in throughput, agricultural scientists and biotech companies can now pursue ambitious genetic engineering projects with enhanced reliability and scalability. The ability to better target shoot apical meristems—where cell division and leaf generation occur—also opens avenues for heritable genome edits, amplifying the impact of genetic improvements across plant generations.
The multidisciplinary team behind this innovation includes doctoral students, seasoned engineers, and plant scientists. Connor Thorpe, a doctoral candidate and avid 3D-printing enthusiast, translated the computational designs into physical barrels for empirical testing. His efforts, alongside contributions from Kyle Miller and Alan Eggenberger, illustrate the power of convergence between engineering and biological sciences. Their entrepreneurial drive led to the establishment of Hermes Biomaterials Inc., a startup launched with support from Iowa State’s commercialization programs and backed by the U.S. Department of Energy’s Small Business Technology Transfer (STTR) initiative.
Ahead of the commercial launch, the research group tested the Flow Guiding Barrel extensively across various plant species and genetic platforms. Professors Kan Wang and Yiping Qi from the University of Maryland underscored the barrel’s potential, highlighting its ability to make genome editing with CRISPR not only more efficient but also more robust across diverse crop species. Qi noted that the solution could extend its benefits to cereal crops such as barley and sorghum, among others, thereby impacting a wide swath of global agriculture.
This breakthrough stands as a vivid testament to the untapped synergy between engineering and plant science, demonstrating that innovations often emerge from viewing old problems through fresh disciplinary lenses. The Flow Guiding Barrel’s simplicity belies its profound impact—by refining fluid flow dynamics inside an existing tool, it overcomes four decades of entrenched limitations, accelerating the pace of crop improvement in a world facing climate uncertainty and increasing food demand.
Supported by the Digital and Precision Agriculture Research and Innovation Platform and funded by multiple agencies including the USDA’s Agriculture and Food Research Initiative, the National Science Foundation, and the Department of Energy, the work exemplifies how coordinated scientific investment can deliver disruptive advances. As Hermes Biomaterials begins commercial production of the Flow Guiding Barrel, the research team plans ongoing collaborations to further optimize the technology, explore additional plant species, and potentially adapt the approach for broader gene delivery applications.
Looking ahead, the implications of this technology extend beyond agriculture into sustainable energy and nutritional enhancement strategies. By empowering scientists with more efficient and precise genome editing tools, the Flow Guiding Barrel promises to contribute to the development of crops that better withstand environmental stressors such as drought and heat, improve nutritional profiles, and aid in the production of bioenergy. It encapsulates a critical step toward the integration of genetics, engineering, and sustainability science.
In essence, the Flow Guiding Barrel reinvents the gene gun not by reinventing the firearm, but by refining the barrel through which the genetic payload is delivered, unlocking a realm of possibilities for plant biotechnology. Its remarkable efficiency gains and adaptability signal a new era where previously insurmountable biological challenges can be tackled with elegant engineering solutions, ultimately benefiting researchers, farmers, and society at large.
Subject of Research: Cells
Article Title: Enhancing biolistic plant transformation and genome editing with a flow guiding barrel
Web References: http://dx.doi.org/10.1038/s41467-025-60761-x
Image Credits: Photo by Ryan Riley/Iowa State University College of Engineering
Keywords: gene gun, biolistic delivery, plant transformation, genome editing, flow guiding barrel, CRISPR, genetic modification, plant biotechnology, fluid dynamics, Iowa State University, Hermes Biomaterials, agricultural innovation
