About

Brian Belardi is an Assistant Professor in the McKetta Department of Chemical Engineering at The University of Texas at Austin. He serves on the Graduate Studies Committee for both the Interdisciplinary Life Sciences and the Department of Chemistry. Dr. Belardi completed his Ph.D. in Chemistry at the University of California, Berkeley, where he was mentored by Professor Carolyn Bertozzi. He also conducted postdoctoral research as an NIH Postdoctoral Fellow in Bioengineering at the University of California, Berkeley under the mentorship of Professor Daniel Fletcher. Prior to his graduate studies, he earned a B.S. in Chemistry from Carnegie Mellon University, working with Professor Krzysztof Matyjaszewski.

Research topics

• Biology
• Cell biology
• Biochemistry
• Biophysics
• Chemistry

Selected publications

• Insertion-Ligation Reconstitution of Transmembrane Proteins for Functional Interfaces in Synthetic Cells

  ChemRxiv · 2026-03-29

  articleOpen accessSenior author

  In living cells, transmembrane (TM) proteins transduce extracellular cues across a lipid bilayer, a structure which is otherwise impermeable to high molecular weight and charged molecules. Synthetic cells (SCs), lipid bilayer-based systems that offer complete control over composition and response, have emerged as attractive candidates for programmable transduction in biomedicine, sensing, and computing applications. However, SCs lack the complex machinery native to living cells that inserts TM proteins into lipid membranes, limiting their potential for extracellular-to-intracellular transduction. Here, we present a two-step chemical method to reconstitute functional single-pass TM proteins in SCs, termed insertion-ligation. Using the insertion-ligation approach, we report reconstitution of SC-SC interfaces that transduce extracellular adhesion activity into intracellular organization and transmembrane complexes capable of signal transduction across the bilayer. Our chemical strategy enables reconstitution of any single-pass TM proteins in SCs, allowing researchers to access this functionally diverse class of proteins without the need for insertion machinery.

  PublisherOA PDFDOI

• Passive nuclear transport deviates from Fickian behavior in prostate and breast cell types

  Figshare · 2026-01-01

  datasetOpen access

  Nuclear trafficking is essential for cellular function and biomedical applications such as nucleus-targeted drug delivery; however, how passive nuclear transport varies across cell types and phenotypic states remains poorly understood. Here, we investigate passive nuclear transport of fluorescent molecular cargoes spanning 500–20,000 Da across multiple cell lines. We observe cell-line-specific nuclear restrictions and find that passive nuclear uptake does not exhibit a monotonic dependence on molecular weight, suggesting non-Fickian transport behavior. Furthermore, transforming a healthy breast cell model into an invasive-like phenotype via TGF-Beta treatment significantly altered passive nuclear transport characteristics, closely resembling those of a well-established invasive breast cancer cell line. These phenotype-dependent changes in nuclear permeability provide new insight into fundamental biophysical alterations associated with cancerous cellular transformation.

  PublisherDOI

• Passive nuclear transport deviates from Fickian behavior in prostate and breast cell types

  Nucleus · 2026-01-31

  articleOpen access

  Nuclear trafficking is essential for cellular function and biomedical applications such as nucleus-targeted drug delivery; however, how passive nuclear transport varies across cell types and phenotypic states remains poorly understood. Here, we investigate passive nuclear transport of fluorescent molecular cargoes spanning 500-20,000 Da across multiple cell lines. We observe cell-line-specific nuclear restrictions and find that passive nuclear uptake does not exhibit a monotonic dependence on molecular weight, suggesting non-Fickian transport behavior. Furthermore, transforming a healthy breast cell model into an invasive-like phenotype via TGF-Beta treatment significantly altered passive nuclear transport characteristics, closely resembling those of a well-established invasive breast cancer cell line. These phenotype-dependent changes in nuclear permeability provide new insight into fundamental biophysical alterations associated with cancerous cellular transformation.

  PublisherDOI

• Passive nuclear transport deviates from Fickian behavior in prostate and breast cell types

  Open MIND · 2026-01-01

  dataset

  Nuclear trafficking is essential for cellular function and biomedical applications such as nucleus-targeted drug delivery; however, how passive nuclear transport varies across cell types and phenotypic states remains poorly understood. Here, we investigate passive nuclear transport of fluorescent molecular cargoes spanning 500–20,000 Da across multiple cell lines. We observe cell-line-specific nuclear restrictions and find that passive nuclear uptake does not exhibit a monotonic dependence on molecular weight, suggesting non-Fickian transport behavior. Furthermore, transforming a healthy breast cell model into an invasive-like phenotype via TGF-Beta treatment significantly altered passive nuclear transport characteristics, closely resembling those of a well-established invasive breast cancer cell line. These phenotype-dependent changes in nuclear permeability provide new insight into fundamental biophysical alterations associated with cancerous cellular transformation.

  DOI

• Inhibition of endocytosis by glycans arises from steric rather than electrostatic repulsion

  Biophysical Journal · 2026-03-13

  article
  PublisherDOI

• A balance between nucleating and elongating actin filaments controls deformation of protein condensates

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-06-21 · 2 citations

  preprintOpen access

  Protein condensates use multivalent binding and surface tension to assemble actin filaments into diverse architectures, reminiscent of filopodia and stress fibers. During this process, nucleation of new filaments and elongation of existing filaments inherently compete for a shared pool of actin monomers. Here we show that a balance between these competing processes is required to deform condensates of VASP, an actin binding protein, into structures with high aspect ratios. Addition of magnesium, which promotes filament nucleation, helped actin to deform condensates into high aspect ratio structures. In contrast, addition of profilin, which inhibits filament nucleation, allowing existing filaments to elongate, caused actin to assemble into ring-like bundles that failed to substantially increase condensate aspect ratio. Computational modeling helped to explain these results by predicting that a group of short linear filaments, which can apply asymmetric pressure to the condensate boundary, is needed to increase condensate aspect ratio. In contrast, a small number of long filaments with the same total actin content should fail to overcome the droplet surface tension, forming a ring-like bundle. To test these predictions, we introduced gelsolin, which severed log filaments within rings, creating new barbed ends. The resulting set of shorter filaments regained the ability to deform condensates into high aspect ratio structures. Collectively, these results suggest that a balance of actin filament nucleation and elongation is required to deform protein condensates. More broadly, these findings illustrate how protein condensates can balance multiple kinetic processes to direct the assembly of diverse cytoskeletal architectures.

  PublisherDOI

• Light-Controlled Synthetic Communication Networks via Paired Connexon Nanopores

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-04-11

  preprintOpen accessSenior author

  Living cells employ dynamic networks for intercellular communication and cooperation, leading to tissue-wide activity. One emerging challenge in the field of bottom-up synthetic biology is emulating such sophisticated behaviors in liposome-based synthetic cells (SCs). Fabricating communication networks in lipid bilayer-based SCs remains a challenge as signaling molecules must transit through two consecutive membranes to transfer information between different SCs. Here, we address this obstacle by engineering connexin channels that directly connect the lumens of adhering SC membranes. We focus on orthogonal channel-forming connexins, namely connexin 43 and connexin 32, and re-design their channel activity to be UV- and near IR-responsive, respectively. By combining engineered connexins into a single SC assembly, we demonstrate orthogonal transfer of reactive signaling molecules between SCs, giving rise to unique reaction products and network states in a wavelength-dependent manner - an important step toward synthetic communication networks.

  PublisherOA PDFDOI

• Light-controlled synthetic communication networks via paired connexon nanopores

  Nature Communications · 2025-11-22 · 1 citations

  articleOpen accessSenior author

  Living cells employ dynamic networks for intercellular communication and cooperation, leading to tissue-wide activity. One emerging challenge in the field of bottom-up synthetic biology is emulating such sophisticated behaviors in liposome-based synthetic cells (SCs). Fabricating communication networks in lipid bilayer-based SCs remains a challenge, as signaling molecules must transit through two consecutive membranes to transfer information between different SCs. Here, we address this obstacle by engineering connexin channels that directly connect the lumens of adhering SC membranes. We focus on orthogonal channel-forming connexins, namely connexin 43 and connexin 32, and redesign their channel activity to be UV- and near IR-responsive, respectively. By combining engineered connexins into a single SC assembly, we demonstrate orthogonal transfer of reactive signaling molecules between SCs, giving rise to unique reaction products and network states in a wavelength-dependent manner – an important step toward synthetic communication networks. Replicating intercellular communication in synthetic cells is challenging. Here, the authors report on engineered connexin nanopores that can be controlled with light to exchange distinct chemical signals between synthetic cells, creating programmable communication networks that mimic cellular interactions.

  PublisherDOI

• Paracellular Delivery of Protein Drugs with Smart EnteroPatho Nanoparticles

  ACS Nano · 2024-08-03 · 8 citations

  articleOpen accessSenior authorCorresponding

  A general platform for the safe and effective oral delivery of biologics would revolutionize the administration of protein-based drugs, improving access for patients and lowering the financial burden on the health-care industry. Because of their dimensions and physiochemical properties, nanomaterials stand as promising vehicles for navigating the complex and challenging environment in the gastrointestinal (GI) tract. Recent developments have led to materials that protect protein drugs from degradation and enable controlled release in the small intestine, the site of absorption for most proteins. Yet, once present in the small intestine, the protein must transit through the secreted mucus and epithelial cells of the intestinal mucosa into systemic circulation, a process that remains a bottleneck for nanomaterial-based delivery. One attractive pathway through the intestinal mucosa is the paracellular route, which avoids cell trafficking and other degradative processes in the interior of cells. Direct flux between cells is regulated by epithelial tight junctions (TJs) that seal the paracellular space and prevent protein flux. Here, we describe a smart nanoparticle system that directly and transiently disrupts TJs for improved protein delivery, an unrealized goal to-date. We take inspiration from enteropathogenic bacteria that adhere to intestinal epithelia and secrete inhibitors that block TJ interactions in the local environment. To mimic these natural mechanisms, we engineer nanoparticles (EnteroPatho NPs) that attach to the epithelial glycocalyx and release TJ modulators in response to the intestinal pH. We show that EnteroPatho NPs lead to TJ disruption and paracellular protein delivery, giving rise to a general platform for oral delivery.

  PublisherOA PDFDOI

• Turn-on protein switches for controlling actin binding in cells

  Nature Communications · 2024-07-11 · 3 citations

  articleOpen accessSenior author

  Within a shared cytoplasm, filamentous actin (F-actin) plays numerous and critical roles across the cell body. Cells rely on actin-binding proteins (ABPs) to organize F-actin and to integrate its polymeric characteristics into diverse cellular processes. Yet, the multitude of ABPs that engage with and shape F-actin make studying a single ABP's influence on cellular activities a significant challenge. Moreover, without a means of manipulating actin-binding subcellularly, harnessing the F-actin cytoskeleton for synthetic biology purposes remains elusive. Here, we describe a suite of designed proteins, Controllable Actin-binding Switch Tools (CASTs), whose actin-binding behavior can be controlled with external stimuli. CASTs were developed that respond to different external inputs, providing options for turn-on kinetics and enabling orthogonality and multiplexing. Being genetically encoded, we show that CASTs can be inserted into native protein sequences to control F-actin association locally and engineered into structures to control cell and tissue shape and behavior.

  PublisherOA PDFDOI

Recent grants

• Synthetic Adhesome Cells: Engineering Interfaces Between Synthetic and Live Cells for Controlled Delivery

  NSF · $1.5M · 2022–2026

• Investigating Tight Junction-Mediated Spatial Organization in Polarized Epithelia.

  NIH · $163k · 2015–2018

• A Molecular Toolkit for Controlling and Probing Cell Junction-Actin Interactions

  NIH · $1.9M · 2021–2027

Frequent coauthors

• Daniel A. Fletcher

  Berkeley College

  31 shared

• Carolyn R. Bertozzi

  Stanford University

  22 shared

• Krzysztof Matyjaszewski

  Carnegie Mellon University

  10 shared

• Geoff P. O’Donoghue

  University of California, San Francisco

  9 shared

• Adam W. Smith

  Texas Tech University

  9 shared

• Lorraine Tessier

  CEA Paris-Saclay

  9 shared

• Jay T. Groves

  University of California, Berkeley

  9 shared

• François Stoffelbach

  Institut Parisien de Chimie Moléculaire

  9 shared

Labs

• Belardi LabPI

Education

• B.S.

  Carnegie Mellon University

  2008

• Ph.D., Chemistry

  University of California, Berkeley

  2014

• Other, Bioengineering

  University of California, Berkeley

  2014

Awards & honors

• David and Lucile Packard Foundation Packard Fellowship for S…
• Advanced Drug Delivery Reviews Emerging Voices in Drug Deliv…
• Maximizing Investigators’ Research Award – National Institut…
• Postdoctoral Association Award – University of California, B…
• Ruth L. Kirschstein NRSA Fellowship – National Institutes of…