Ohio State University scientists have pioneered a new class of nanocarriers, building upon the intrinsic properties of red blood cells. These groundbreaking extracellular vesicles exhibit considerable potential as highly effective conduits for gene therapy, targeted tumor treatment, and various other therapeutic applications.
These sophisticated extracellular vesicles possess the ability to circumvent immune detection and selectively engage with cancer cells. This dual functionality marks a significant advancement, promising to improve the precision and efficacy of future medical treatments. The innovative manufacturing approach leverages microfluidics to construct these vesicles from red blood cell lipids, allowing for unparalleled adaptability in encapsulating a diverse range of therapeutic substances, including genetic material, proteins, and even complete viruses utilized in gene therapy.
During in-vivo studies, these specially engineered vesicles demonstrated extended circulation times and systemic distribution, mirroring the behavior of naturally occurring extracellular vesicles, with a noticeable propensity to accumulate in the lungs. Initially, the research aimed to harness natural red blood cell-derived extracellular vesicles for drug delivery; however, challenges in scalability and cargo flexibility led the team to develop advanced engineering methodologies to surpass the limitations of biological systems. Eduardo Reátegui, a senior author and professor of chemical and biomolecular engineering at The Ohio State University, highlighted the compositional similarity of these engineered vesicles to their natural counterparts, preserving their inherent biocompatibility and advantageous biological characteristics.
The source material for these lipid-based carriers is expired red blood cells, which are typically discarded. This sustainable approach is facilitated by the laboratory of co-author Andre Palmer, also a professor of chemical and biomolecular engineering at Ohio State. Palmer's team routinely purifies hemoglobin from expired red blood cells for the development of blood substitutes, making the utilization of these otherwise waste products a highly efficient and environmentally conscious strategy. The details of this innovative platform were recently unveiled in a study featured in the esteemed journal, Advanced Healthcare Materials.
Extracellular vesicles, which are microscopic, cargo-carrying particles naturally released by cells to facilitate intercellular communication, play a crucial role in both healthy physiological processes and disease progression. The Ohio State team has been at the forefront of exploring how these engineered vesicles can be adapted for a wide array of medical uses. The microfluidics-based manufacturing process not only ensures the biocompatibility afforded by red blood cell lipids but also seamlessly integrates therapeutic cargo during vesicle formation, eliminating the need for subsequent, separate loading procedures.
Reátegui, who is also an esteemed member of The Ohio State University Comprehensive Cancer Center's Cancer Biology Program, emphasized the enhanced control offered by their process. He stated that their method provides superior mastery over the precise composition of these engineered vesicles. Research confirmed that the integration of a CD47 peptide onto the exterior of these carriers effectively shielded them from being misidentified as pathogens and subsequently engulfed by macrophages. Furthermore, the team successfully demonstrated the capacity to engineer these vesicles for targeted tumor delivery by incorporating PD-L1-recognition molecules, including anti-PD-L1 nanobodies developed in the laboratory of co-author Blaise Kimmel. This was evidenced by the preferential uptake of these anti-PD-L1-tagged vesicles by PD-L1-positive breast cancer tumors, a common target for immunotherapies.
These engineered extracellular vesicles hold the potential to emulate the therapeutic benefits of CAR T-cell therapies, which involve modifying a patient's own immune T cells to combat cancer. Palmer suggested that this method could offer a distinct approach to leveraging an individual's red blood cell lipids to encapsulate therapeutic compounds, which could then be readministered to the patient for disease treatment. The microfluidics technique also accommodates the encapsulation of larger molecules, such as entire proteins or adeno-associated viruses (AAVs), which are standard delivery systems in many gene therapies. Reátegui further explained that embedding therapeutic AAVs within engineered red blood cell extracellular vesicles, along with the CD47 peptide, could mitigate the risk of triggering an immune response and protect against neutralizing antibodies, while maintaining the gene therapy's efficacy.
With this sophisticated platform now established, the researchers plan to intensify their efforts on gene therapy and the selective delivery of therapeutics, particularly those designed to exploit the vesicles' natural inclination for pulmonary accumulation. This pioneering research received crucial backing from the National Center for Advancing Translational Sciences, as well as Ohio State's William G. Lowrie Department of Chemical and Biomolecular Engineering and the Comprehensive Cancer Center. Collaborators on this project included Chiranth Nagaraj, Xilal Rima, Kim Nguyen, Courtney Culkins, Nana Boateng, Jacob Doon-Ralls, Alejandro Bresolin, Xin Huang, Vahedi Amid, Ajeet Pal Singh, Dharti Shantaram, Anastasiia Amari, Nicholas Merriam, Zachary Schultz, Willa Hsueh, and Rachel Kopec from Ohio State, alongside Hong Li, Scott Harper, Nizar Saad, and Setty Magaña from Nationwide Children’s Hospital.
The development of these red blood cell-inspired nanocarriers represents a significant leap forward in therapeutic delivery. By harnessing the body's natural mechanisms and combining them with advanced engineering, scientists are paving the way for safer, more effective treatments for a variety of diseases. This innovation underscores the immense potential of biomimicry in medical science, offering hope for highly personalized and precise interventions that minimize adverse effects and maximize patient outcomes. Such advancements highlight a future where therapeutic solutions are not only powerful but also inherently harmonious with biological systems, leading to better health and well-being for all.
