Biology subjects

Scott, E. A.

Publications and source records attributed to Scott, E. A..

16 recordsLinked to original sources

bioRxiv2026

Preserving Nanotherapy-Induced Allogeneic Murine Islet Graft Tolerance During Distal Methicillin-Resistant Staphylococcus aureus Skin Infection

Eliminating lifelong immunosuppression can make islet transplantation a durable alternative to insulin therapy for type 1 diabetes. As short-course tolerogenic regimens are developed to replace lifelong immunosuppression, it is critical to test their robustness against perturbations such as hospital-acquired infections, which transplant recipients routinely encounter. Herein, we investigated whether rapamycin-loaded polymersomes (rPS), a subcutaneous nanotherapy that induces long-term murine islet allograft survival, can preserve host defenses in a Methicillin-resistant Staphylococcus aureus (MRSA) skin infection, and whether the resulting immune response from this distal infection relative to graft location erodes rPS-induced tolerance. rPS maintained neutrophil antibacterial activity despite inhibiting oxidative mechanisms in vitro, and rPS-treated mice demonstrated normal recovery following MRSA challenge. However, MRSA skin infection caused a decline of ~43% in recipient survival for rPS-treated mice, despite surviving recipients retaining glucose-stimulated insulin responsiveness. This erosion of allograft acceptance coincided with a burst of IL-6 within 24h of the infection followed by elevated TNF-[a] and neutrophilia at 13 days post-infection. Combining rPS with a single dose of methylprednisolone reduced IL-6 and TNF- without altering neutrophilia, nearly doubling survival among infected recipients to 80%. Our findings demonstrate that partial dampening of inflammatory insults can restore superior islet allograft acceptance following perioperative infection.

bioengineering↗

bioRxiv2026

Nanotherapy-mediated biased antigen-presenting cell reprogramming supports T cell anergy to prevent type 1 diabetes

Engineering immune tolerance using endogenously expressed autoantigens could enable early intervention in autoimmune disease. Present therapies suppress T cells to slow disease progression. Here, we develop rapamycin-loaded poly(ethylene glycol)-b-poly(propylene sulfide) polymersomes (rPS) to modulate antigen-presenting cells (APCs) during disease-associated antigen presentation. The rPS morphology enables lymphatic drainage following subcutaneous administration to access APCs in draining lymph nodes. Treatment reduced APC costimulatory marker coexpression and shifted CD4+ T cells toward an FR4hi CD73hi anergic phenotype. In a type 1 diabetes (T1D) nonobese diabetic (NOD) mouse model, rPS significantly delayed disease onset relative to the standard of care and selectively prevented hyperglycemia. Mediation via APCs, rPS avoids adverse effects including transient lymphopenia. These findings demonstrate how biomaterial-directed drug delivery can reshape APC--T cell interactions, supporting an antigen-agnostic strategy for delaying autoimmune diabetes without systemic lymphocyte depletion.

bioengineering↗

bioRxiv2025

PROX1 loss in adult mouse Schlemm's canal causes permanent ocular hypertension

Glaucoma is associated with ocular hypertension and lowering intraocular pressure is a key objective of glaucoma therapies. Recent studies have established a role for the Schlemms canal endothelium in this pressure increase and have shown it to have a unique, lymphatic-like, hybrid phenotype. However, the role of these lymphatic phenotypes in the adult canal remains uncertain. Long-term functional studies have been limited by systemic importance of lymphatic genes and lack of Schlemms canal-specific animal models. Here, we designed and validated a strategy using 4OH-tamoxifen-loaded nanocarriers to generate targeted, Schlemms canal specific knockout mice lacking lymphatic phenotypes. Using this system, we selectively deleted Prox1, the master transcription factor governing lymphatic fate. Within four weeks, intraocular pressure significantly increased, and ocular hypertension was maintained for at least 24 weeks. Unlike lymphatic vessels, which degenerate following Prox1 deletion, Schlemms canal reverted to a less functional vein-like phenotype with no change in size or morphology. These results highlight the utility of nanocarriers for tissue-specific genetic recombination and demonstrate that changes in lymphatic phenotypes alter intraocular pressure, providing new targets for glaucoma therapy. Moreover, as we found that PROX1 was downregulated with age in human Schlemms canal, these canal-specific conditional Prox1 knockout mice are a valuable new adult-onset model of ocular hypertension that captures key features of age-related human disease.

physiology↗

bioRxiv2025

Filomicelle-Embedded Composite Hydrogels for Localized Gelation within the Anterior Chamber of the Eye

Nanocarriers hold transformative potential for treating anterior segment eye diseases, yet corneal epithelium impermeability necessitates intraocular injection. Given the discomfort and infection risk, an injectable hydrogel-based depot offers a promising strategy for sustained nanocarrier delivery in intraocular therapy. However, because the aqueous humor is a large, fluid-filled environment, achieving spatially confined gelation remains a key challenge as injected materials rapidly diffuse. Herein, we present a composite hydrogel (C-gel) that enables localized in situ gelation and sustained nanocarrier release within the anterior chamber. This is achieved using poly(ethylene glycol)-b-poly(propylene sulfide) (PEG-b-PPS) filomicelles (FMs), whose filamentous structure confines crosslinking reactions spatially, promoting efficient gel formation. As a result, 90% of the injected polymer is retained within the crosslinked hydrogel matrix. Embedded FMs then undergo oxidation-induced cylinder-to-sphere transitions, facilitating gradual release of micellar nanocarriers. The rheological properties, gelation timing, and microstructure of the C-gel are adjustable, allowing precise control of nanocarrier release dynamics. In vivo evaluation in mice confirmed excellent biocompatibility without inducing intraocular pressure elevation, ocular toxicity, or immune cell infiltration. Sustained release of nanocarriers was observed for over a month under conditions mimicking that of the anterior chamber of the eye, underscoring the potential of C-gels for long-term drug delivery in anterior segment eye diseases therapy.

bioengineering↗

bioRxiv2025

Enabling Organ- and Injury-Specific Nanocarrier Targeting via Surface-Functionalized PEG-b-PPS Micelles for Acute Kidney Injury

While nanomedicine holds great promise for kidney disease, targeted delivery remains a major challenge. Most nanocarriers rely on passive accumulation or epithelial-specific ligands, limiting their utility in complex, inflamed renal environments. In acute kidney injury (AKI), inflammation and vascular dysfunction play central roles, yet targeting strategies beyond the tubule remain underexplored. Here, dual-ligand micelles are developed to enhance nanocarrier localization to the inflamed kidney by simultaneously engaging both organ- and injury-specific cues. Poly(ethylene glycol)-block-poly(propylene sulfide) (PEG-b-PPS) micelles were engineered to display two peptide ligands: CLPVASC, which preferentially distributes to the kidney, and CYNTTTHRC, which binds selectively to inflamed endothelium. These targeting motifs were incorporated via lipid-anchored peptide amphiphiles, enabling modular surface functionalization without disrupting micelle morphology, size, or charge. In vitro, dual-targeted micelles demonstrated enhanced uptake by human endothelial cells exposed to hypoxia-reoxygenation. In vivo, following unilateral renal ischemia-reperfusion injury (IRI) in mice, targeted micelles achieved selective accumulation in the injured kidney, outperforming both non-targeted controls and contralateral kidneys. Off-target distribution to liver, lung, and spleen was markedly reduced, confirming the spatial precision of the dual-ligand approach. This strategy offers a scalable, modular, and biologically informed platform for precision delivery in AKI and related inflammatory conditions.

bioengineering↗

bioRxiv2024

Therapeutic expression of RAS Degrader RRSP in Pancreatic Cancer via Nanocarrier-mediated mRNA delivery

Therapeutic gene expression can address many of the challenges associated with the controlled delivery of intracellularly active biologics, such as enzymes that degrade RAS for treatment of RAS-driven cancers. Here, we demonstrate that an optimized synthetic nonviral gene delivery platform composed of poly(ethylene glycol)-b-poly(propylene sulfide) (PEG-PPS) can block copolymers conjugated to a dendritic cationic peptide (PPDP2) for nontoxic delivery and therapeutic expression of mRNA within human pancreatic cancer cells and tumors. The naturally occurring bacterial enzyme RAS/RAP1-specific endopeptidase (RRSP) is a potent RAS degrader that specifically targets all RAS isoforms. Using PPDP2, rrsp-mRNA is delivered to human pancreatic cells resulting in RRSP protein expression, degradation of RAS, and loss of cell proliferation. Further, pancreatic tumors are reduced with residual tumors lacking detectable RAS and phosphorylated ERK. Using structural modeling, we further demonstrate that a noncatalytic RAS-binding domain of RRSP provides high specificity for RAS. These data support that the synthetic nanocarrier PPDP2 can deliver rrsp-mRNA to pancreatic tumor cells to interrupt the RAS signaling system.

cancer biology↗

bioRxiv2023

Cerebrospinal Fluid Flow Extends to Peripheral Nerves

Cerebrospinal fluid (CSF) is an aqueous solution responsible for nutrient delivery and waste removal for the central nervous system (CNS). The three-layer meningeal coverings of the CNS support CSF flow. Peripheral nerves have an analogous three-layer covering consisting of the epineurium, perineurium, and endoneurium. Peripheral axons, located in the inner endoneurium, are bathed in "endoneurial fluid" similar to CSF but of undefined origin. CSF flow in the peripheral nervous system has not been demonstrated. Here we show CSF flow extends beyond the CNS to peripheral nerves in a contiguous flowing system. Utilizing gold nanoparticles, we identified that CSF is continuous with the endoneurial fluid and reveal the endoneurial space as the likely site of CSF flow in the periphery. Nanogold distribution along entire peripheral nerves and within their axoplasm suggests CSF plays a role in nutrient delivery and waste clearance, fundamental aspects of peripheral nerve health and disease. One Sentence SummaryCerebrospinal fluid unites the nervous system by extending beyond the central nervous system into peripheral nerves.

neuroscience↗

bioRxiv2023

Design of a symmetry-broken tetrahedral protein cage by a method of internal steric occlusion

Methods in protein design have made it possible to create large and complex, self-assembling protein cages with diverse applications. These have largely been based on highly symmetric forms exemplified by the Platonic solids. Prospective applications of protein cages would be expanded by strategies for breaking the designed symmetry, e.g., so that only one or a few (instead of many) copies of an exterior domain or motif might be displayed on their surfaces. Here we demonstrate a straightforward design approach for creating symmetry-broken protein cages able to display singular copies of outward-facing domains. We modify the subunit of an otherwise symmetric protein cage through fusion to a small inward-facing domain, only one copy of which can be accommodated in the cage interior. Using biochemical methods and native mass spectrometry, we show that co-expression of the original subunit and the modified subunit, which is further fused to an outward-facing anti-GFP DARPin domain, leads to self-assembly of a protein cage presenting just one copy of the DARPin protein on its exterior. This strategy of designed occlusion provides a facile route for creating new types of protein cages with unique properties.

biochemistry↗

bioRxiv2023

Vaccination with mycobacterial lipid loaded nanoparticle leads to lipid antigen persistence and memory differentiation of antigen-specific T cells

Mycobacterium tuberculosis (Mtb) infection elicits both protein and lipid antigen-specific T cell responses. However, the incorporation of lipid antigens into subunit vaccine strategies and formulations has been underexplored, and the characteristics of vaccine-induced Mtb lipid-specific memory T cells have remained elusive. Mycolic acid (MA), a major lipid component of the Mtb cell wall, is presented by human CD1b molecules to unconventional T cell subsets. These MA-specific CD1b-restricted T cells have been detected in the blood and disease sites of Mtb-infected individuals, suggesting that MA is a promising lipid antigen for incorporation into multicomponent subunit vaccines. In this study, we utilized the enhanced stability of bicontinuous nanospheres (BCN) to efficiently encapsulate MA for in vivo delivery to MA-specific T cells, both alone and in combination with an immunodominant Mtb protein antigen (Ag85B). Pulmonary administration of MA-loaded BCN (MA-BCN) elicited MA-specific T cell responses in humanized CD1 transgenic mice. Simultaneous delivery of MA and Ag85B within BCN activated both MA- and Ag85B-specific T cells. Notably, pulmonary vaccination with MA-Ag85B-BCN resulted in the persistence of MA, but not Ag85B, within alveolar macrophages in the lung. Vaccination of MA-BCN through intravenous or subcutaneous route, or with attenuated Mtb likewise reproduced MA persistence. Moreover, MA-specific T cells in MA-BCN-vaccinated mice differentiated into a T follicular helper-like phenotype. Overall, the BCN platform allows for the dual encapsulation and in vivo activation of lipid and protein antigen-specific T cells and leads to persistent lipid depots that could offer long-lasting immune responses.

immunology↗

bioRxiv2022

Shaping neonatal immunization by tuning delivery of synergistic adjuvants via nanocarriers

Adjuvanted nanocarrier-based vaccines hold substantial potential for applications in novel early-life immunization strategies. Here, via mouse and human age-specific in vitro modelling, we identified the combination of a small molecule STING agonist (2'3'-cyclic GMP-AMP, cGAMP) and a TLR7/8 agonist (CL075) to drive synergistic activation of neonatal dendritic cells and precision CD4 Th cell expansion via the IL-12/IFN{gamma} axis. We further demonstrate that vaccination of neonatal mice with quadrivalent influenza recombinant hemagglutinin (rHA) and an admixture of two polymersome (PS) nanocarriers separately encapsulating-cGAMP (cGAMP-PS) and CL075 (CL075-PS) drove robust T helper (Th)1 bias, high frequency of T follicular helper (TFH) cells and germinal center B (GC B) cells along with IgG2c-skewed humoral response in vivo. Dual loaded cGAMP/CL075-PSs did not outperform admixed cGAMP-PSs and CL075-PSs in vivo. These data validate an optimally designed adjuvantation system, via age-selected small molecule synergy and a multi-component nanocarrier formulation, as an effective approach to induce type 1 immune responses in early life.

immunology↗

bioRxiv2021

Targeted Delivery of Chloroquine to Plasmacytoid Dendritic Cells Enhances Inhibition of the Type I Interferon Response

Systemic lupus erythematosus (SLE) causes damaging inflammation in multiple organs via the accumulation of immune complexes. These complexes activate plasmacytoid DCs (pDCs) via TLR7 and TLR9, contributing to disease pathogenesis by driving secretion of inflammatory type I IFNs. Antimalarial drugs, such as chloroquine (CQ), are TLR antagonists used to alleviate inflammation in SLE. However, they require ~3 months of continuous use before achieving therapeutic efficacy and can accumulate in the retinal pigment epithelium with chronic use resulting in retinopathy. We hypothesized that poly(ethylene glycol)-b-poly(propylene sulfide) (PEG-b-PPS) filamentous nanocarriers, filomicelles (FMs) could improve drug activity and reduce toxicity by directly delivering CQ to pDCs via passive, morphology-based targeting. Healthy human PBMCs were treated with soluble CQ or CQ-loaded FMs, stimulated with TLR agonists or SLE patient sera, and type I IFN secretion was quantified via multi-subtype IFN- ELISA and MX1 gene expression using real-time RT-qPCR. Our results showed that 50 {micro}g CQ/mg FM decreased MX1 expression and IFN- production after TLR activation with either synthetic nucleic acid agonists or immune complex rich sera from SLE patients. Cellular uptake and biodistribution studies showed that FMs preferentially accumulate in human pDCs in vitro and in tissues frequently damaged in SLE patients (i.e., liver and kidneys) while sparing the eye in vivo. These results showed that nanocarrier morphology enables drug delivery, and CQ-FMs may be equally effective and more targeted than soluble CQ at inhibiting SLE-relevant pathways.

bioengineering↗

bioRxiv2021

Surface Engineering of FLT4-Targeted Nanocarriers Enhances Cell-Softening Glaucoma Therapy

Primary open-angle glaucoma is associated with elevated intraocular pressure (IOP) that damages the optic nerve and leads to gradual vision loss. Several agents that reduce the stiffness of pressure-regulating Schlemms canal endothelial cells, in the conventional outflow pathway of the eye, lower IOP in glaucoma patients and are approved for clinical use. However, poor drug penetration and uncontrolled biodistribution limit their efficacy and produce local adverse effects. Compared to other ocular endothelia, FLT4/VEGFR3 is expressed at elevated levels by Schlemms canal endothelial cells and can be exploited for targeted drug delivery. Here, we validate FLT4 receptors as a clinically relevant target on Schlemms canal cells from glaucomatous human donors and engineer polymeric self-assembled nanocarriers displaying lipid-anchored targeting ligands that optimally engage this receptor. Targeting constructs were synthesized as lipid-PEGX-peptide, differing in the number of PEG spacer units (x), and were embedded in micelles. We present a novel proteolysis assay for quantifying ligand accessibility that we employ to design and optimize our FLT4-targeting strategy for glaucoma nanotherapy. Peptide accessibility to proteases correlated with receptor-mediated targeting enhancements. Increasing the accessibility of FLT4-binding peptides enhanced nanocarrier uptake by Schlemms canal cells while simultaneously decreasing uptake by off-target vascular endothelial cells. Using a paired longitudinal IOP study in vivo, we show this enhanced targeting of Schlemms canal cells translates to IOP reductions that are sustained for a significantly longer time as compared to controls. Histological analysis of murine anterior segment tissue confirmed nanocarrier localization to Schlemms canal within one hour after intracameral administration. This work demonstrates that steric effects between surface-displayed ligands and PEG coronas significantly impact targeting performance of synthetic nanocarriers across multiple biological scales. Minimizing the obstruction of modular targeting ligands by PEG measurably improved the efficacy of glaucoma nanotherapy and is an important consideration for engineering PEGylated nanocarriers for targeted drug delivery.

bioengineering↗

bioRxiv2020

Subcutaneous nanotherapy repurposes the immunosuppressive mechanism of rapamycin to enhance allogeneic islet graft viability

Oral rapamycin administration rapamycin is plagued by poor bioavailability and wide biodistribution. Thus, this pleotropic mTOR inhibitor has a narrow therapeutic window, numerous side effects and provides inadequate transplantation protection. Parental formulation was not possible due to rapamycins hydrophobicity (log P 4.3). Here, we demonstrate that subcutaneous rapamycin delivery via poly(ethylene glycol)-b-poly(propylene sulfide)(PEG-b-PPS) polymersome (PS) nanocarriers modulates cellular biodistribution of rapamycin to change its immunosuppressive mechanism for enhanced efficacy while minimizing side effects. While oral rapamycin inhibits naive T cell proliferation directly, subcutaneously administered rapamycin-loaded polymersomes (rPS) instead modulated Ly-6Clow monocytes and tolerogenic semi-mature dendritic cells, with immunosuppression mediated by CD8+ Tregs and rare CD4+ CD8+ double-positive T cells. As PEG-b-PPS PS are uniquely non-inflammatory, background immunostimulation from the vehicle was avoided, allowing immunomodulation to be primarily attributed to rapamycins cellular biodistribution. Repurposing mTOR inhibition significantly improved maintenance of normoglycemia in a clinically relevant, MHC-mismatched, allogeneic, intraportal (liver) islet transplantation model. These results demonstrate the ability of engineered nanocarriers to repurpose drugs for alternate routes of administration by rationally controlling cellular biodistribution.

bioengineering↗

bioRxiv2020

The Combination of Morphology and Surface Chemistry Defines the Biological Identity of Nanocarriers in Human Blood

Following intravenous administration, an adsorbed corona of blood proteins immediately forms on the surfaces of nanocarriers to confer a distinct biological identity that dictates interactions with the immune system. While the nanocarrier surface chemistry has long been the focus of protein corona formation, the influence of the nanocarrier structure has remained unclear despite well-documented influences on biodistribution, clearance and inflammation. Here, we present design rules for the combined engineering of both nanocarrier structure and surface chemistry derived from a comprehensive proteomic analysis of protein corona formation in human blood. A library of nine soft PEGylated nanocarriers that differ in their combination of morphology (spheres, vesicles, and cylinders) and surface chemistry (methoxy, hydroxyl, and phosphate) were synthesized to represent properties of commonly employed drug delivery vehicles. Using label-free proteomics and high-throughput techniques, we examined the relationship between physicochemical properties and the resulting nanocarrier biological identity, including dynamic changes in protein corona composition, differential immunostimulation and uptake by relevant immune cell populations. In human blood, non-polar spherical micelles developed a similar biological identity to polar vesicles, whereas the identities of polar spheres and cylinders resembled that of non-polar vesicles. The formed protein coronas were compositionally dynamic and morphology-dependent, and these time-dependent fingerprints altered nanocarrier complement activation as well as their uptake by human monocytes, macrophages, and dendritic cells. This comprehensive analysis provides mechanistic insights into rational design choices that impact nanocarrier fate in human blood. One Sentence SummaryWe demonstrate that not only the surface chemistry, but the combined chemical and structural properties of soft drug delivery vehicles impact the composition of blood proteins that adsorb to their surfaces, and these differences specify their interactions with and modulation of human immune cells.

bioengineering↗

bioRxiv2020

Co-administration of macropinocytosis inhibitory nanoparticles (MiNP) for enhanced nanoparticle circulation time and target tissue accumulation following subcutaneous injection

A signficant barrier to the application of nanoparticles for precision medicine is the mononuclear phagocyte system (MPS), a diverse population of phagocytic cells primarily located within the liver, spleen and lymph nodes. The majority of nanoparticles are indiscriminantly cleared by the MPS via macropinocytosis before reaching their intended targets, resulting in side effects and decreased efficacy. This work demonstrates that the biodistribution and desired tissue accumulation of targeted nanoparticles can be significantly enhanced by co-injection with polymeric micelles containing the actin depolymerizing agent latrunculin A. These macropinocytosis inhibitory nanoparticles (MiNP) were found to selectively inhibit non-specific uptake of a second "effector" nanoparticle in vitro without impeding receptor-mediated endocytosis. In tumor bearing mice, co-injection with MiNP in a single multi-nanoparticle formulation significantly increased the accumulation of folate-receptor targeted nanoparticles within tumors. Furthermore, subcutaneous co-administration with MiNP allowed effector nanoparticles to achieve serum levels that rivaled a standard intravenous injection. This effect was only observed if the effector nanoparticles were injected within 24 h following MiNP administration, indicating a temporary avoidance of MPS cells. Co-injection with MiNP therefore allows reversible evasion of the MPS for targeted nanoparticles and presents a previously unexplored method of modulating and improving nanoparticle biodstribution following subcutaneous administration. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=194 SRC="FIGDIR/small/267054v1_ufig1.gif" ALT="Figure 1"> View larger version (54K): org.highwire.dtl.DTLVardef@e2e675org.highwire.dtl.DTLVardef@883af7org.highwire.dtl.DTLVardef@1d74912org.highwire.dtl.DTLVardef@fe6bd9_HPS_FORMAT_FIGEXP M_FIG C_FIG TOC Text: Polymeric macropinocytosis inhibiting nanoparticles reduce non-specific uptake of an "effector" nanoparticle by cells of the mononuclear phagocyte system. This macropinocytosis specific inhibition allows for greater accumulation and uptake of targeted nanoparticles in tissues of interest thereby increasing their efficacy and reducing side effects.

bioengineering↗

bioRxiv2020

Surface chemistry-mediated modulation of adsorbed albumin folding state specifies nanocarrier clearance by distinct macrophage subsets

Controlling nanocarrier interactions with the immune system requires a thorough understanding of the surface properties that modulate protein adsorption in biological fluids, since the resulting protein corona redefines cellular interactions with nanocarrier surfaces. Albumin is initially the dominant protein to adsorb to nanobiomaterial surfaces, a process that is considered benign or beneficial by minimizing opsonization or inflammation. Here, we demonstrate the surface chemistry of a model self-assembled nanocarrier can be engineered to stabilize or denature the three-dimensional conformation of adsorbed albumin, which respectively promotes evasion or non-specific clearance in vivo. Interestingly, certain common chemistries that have long been considered to convey stealth properties were found to promote albumin recognition by macrophage class A1 scavenger receptors (SR-A1), providing a means for their eventual removal from systemic circulation. We establish that the surface chemistry of nanocarriers can be specified to modulate adsorbed albumin structure and thereby tune clearance by macrophage scavenger receptors.

bioengineering↗