Biology subjects

Song, Y. E.

Publications and source records attributed to Song, Y. E..

5 recordsLinked to original sources

bioRxiv2025

Preventing peritendinous adhesions using lubricious supramolecular hydrogels

Of the 1.5 million emergency room visits each year in the United States due to flexor tendon injuries in the hand, over 30-40% result in peritendinous adhesions which can limit range of motion (ROM) and severely impact an individuals quality of life. Adhesions are fibrous scar-like tissues which can form between adjacent tissues in the body in response to injury, inflammation, or during normal healing following surgery. Currently, there is no widespread solution for adhesion prevention in the delicate space of the digit while allowing a patient full ROM quickly after surgery. There is a clear clinical need for a material capable of limiting adhesion formation which is simple to apply, does not impair healing, remains at the application site during motion and initial inflammation (days - weeks), and leaves tendon glide unencumbered. In this work, we developed dynamically crosslinked, bioresorbable supramolecular hydrogels as easy-to-apply lubricious barriers to prevent the formation of peritendinous adhesions. These hydrogels exhibit excellent long-term stability, injectability, and thermally stable viscoelastic properties that allow for simple storage and facile application. We evaluated interactions at the interface of the hydrogels and relevant tissues, including human tendon and skin, in shear and extensional stress modes and demonstrated a unique mechanism of adhesion prevention based on maintenance of a lubricious hydrogel barrier between tissues. Ex vivo studies show that the hydrogels did not impair the gliding behavior nor mechanical properties of tendons when applied in cadaveric human hands following clinically relevant flexor tendon repair. We further applied these hydrogels in a preclinical rat Achilles tendon injury model and observed prolonged local retention at the repair site as well as improved recovery of key functional metrics, including ROM and maximal dorsiflexion. Further, these hydrogels were safe and did not impair tendon strength nor healing compared to the current standard of care. These dynamic, biocompatible hydrogels present a novel solution to the significant problem of peritendinous adhesions with clear translational potential.

bioengineering↗

bioRxiv2024

Highly extensible physically crosslinked hydrogels for high-speed 3D bioprinting

Hydrogels have emerged as promising materials for bioprinting and many other biomedical applications due to their high degree of biocompatibility and ability to support and/or modulate cell viability and function. Yet, many hydrogel bioinks have suffered from low efficiency due to limitations on accessible printing speeds, often limiting cell viability and/or the constructs which can be generated. In this study, we report a highly extensible bioink system created by modulating the rheology of physically crosslinked hydrogels comprising hydrophobically-modified cellulosics and either surfactants or cyclodextrins. We demonstrate that these hydrogels are highly shear-thinning with broadly tunable viscoelasticity and stress-relaxation through simple modulation of the composition. Rheological experiments demonstrate that increasing concentration of rheology-modifying additives yields hydrogel materials exhibiting extensional strain-to-break values up to 2000%, which is amongst the most extensible examples of physically crosslinked hydrogels of this type. We demonstrate the potential of these hydrogels for use as bioinks by evaluating the relationship between extensibility and printability, demonstrating that greater hydrogel extensibility enables faster print speeds and smaller print features. Our findings suggest that optimizing hydrogel extensibility can enhance high-speed 3D bioprinting capabilities, reporting over 5000-fold enhancement in speed index compared to existing works reported for hydrogel-based bioinks in extrusion-based printing.

bioengineering↗

bioRxiv2024

Generation of an inflammatory niche in an injectable hydrogel depot through recruitment of key immune cells improves efficacy of mRNA vaccines

Messenger RNA (mRNA) delivered in lipid nanoparticles (LNPs) rose to the forefront of vaccine candidates during the COVID-19 pandemic due in part to scalability, adaptability, and potency. Yet there remain critical areas for improvements of these vaccines in durability and breadth of humoral responses. In this work, we explore a modular strategy to target mRNA/LNPs to antigen presenting cells with an injectable polymer-nanoparticle (PNP) hydrogel depot technology which recruits key immune cells and forms an immunological niche in vivo. We characterize this niche on a single cell level and find it is highly tunable through incorporation of adjuvants like MPLAs and 3M-052. Delivering commercially available SARS-CoV-2 mRNA vaccines in PNP hydrogels improves the durability and quality of germinal center reactions, and the magnitude, breadth, and durability of humoral responses. The tunable immune niche formed within PNP hydrogels effectively skews immune responses based on encapsulated adjuvants, creating opportunities to precisely modulate mRNA/LNP vaccines for various indications from infectious diseases to cancers.

bioengineering↗

bioRxiv2024

Star-polymers as potent broad-spectrum extracellular virucidal antivirals

Viruses pose a significant threat to both global health and the global economy. It is clear that novel antiviral strategies are urgently needed, with a broad-spectrum approach being most desired. We have discovered a broad-spectrum, non-toxic polymer virucide that can tackle the viral threat. This polymeric virucide is effective at nanomolar concentrations, against a broad-spectrum of viruses and, demonstrated using an intranasal respiratory syncytial virus (RSV) murine model, has excellent efficacy, low anti-coagulant properties and low toxicity in vivo. Molecular dynamic simulations show that this polymer achieves its virucidal antiviral effect via self-assembly of viral-receptors leading to increased envelope forces and viral disassembly. The discovery of this cheap and readily produced polymer marks the start of a new type of receptor-crosslinking broad-spectrum antiviral that has significant potential to combat the global threat posed by viruses.

microbiology↗

bioRxiv2024

Sustained vaccine exposure elicits more rapid, consistent, and broad humoral immune responses to multivalent influenza vaccines

With the ever-present threat of pandemics, it is imperative we develop vaccine technologies eliciting broad and durable immunity to high-risk pathogens. Yet, current annual influenza vaccines, for example, fail to provide robust immunity against the 3-4 homologous strains they contain, let alone heterologous strains. Herein, we demonstrate that sustained delivery of multivalent influenza vaccines from an injectable polymer-nanoparticle (PNP) hydrogel technology induces more rapid, consistent, and potent humoral immune responses against multiple homologous viruses, as well as potent responses against heterologous viruses and potential pandemic subtypes H5N1, H7N9 and H9N2. Further, admixing PNP hydrogels with commercial influenza vaccines results in stronger hemagglutination inhibition against both heterologous and homologous viruses. We show this enhanced potency and breadth arises from higher affinity antibodies targeting both the hemagglutinin stem and head. Overall, this simple and effective sustained delivery platform for multivalent annual influenza vaccines generates durable, potent, and remarkably broad immunity to influenza.

bioengineering↗