Myers, Cheryl

ABSTRACT Biofilm‐associated staphylococcal infections remain exceptionally difficult to treat due to the presence of resilient staphylococcal biofilms and the limited effectiveness of currently available antibiotics. To combat persistent infections, providers are often forced to use prolonged courses of combination antimicrobial therapies that have significant toxicities with limited effectiveness, leading to increased hospital stays, substantial health care costs and a rise in patient morbidity and mortality. Staphylococcus aureus is a dominant cause of recalcitrant biofilms, for which novel non‐antibiotic therapeutics are critically needed. Lysins, a class of protein‐based antimicrobials, rapidly kill staphylococci, exhibit potent anti‐biofilm activity, have a low propensity of resistance development and synergy with antibiotics. To address this unmet need, we evaluate an extracellular vesicle (EV)‐based delivery platform for the engineered anti‐staphylococcal lysin LYSG101, designed to improve stability and localization at sites of infection. Initial proof‐of‐concept work is provided here, demonstrating that human serum‐derived EVs can be loaded with LYSG101 to exert a potent in vitro antimicrobial effect against both planktonic and biofilm forms of S. aureus . EV‐mediated delivery achieved activity equivalent to free lysin, with additional translational advantages including stability and the potential for sustained intra‐articular retention. This work supports further development of the EV‐mediated lysin delivery as a broadly applicable antimicrobial platform, with potential future applications in biofilm‐associated infections, including prosthetic joint infection (PJI).

ABSTRACT Objective To compare antigen removal processing with conventional sodium dodecyl sulfate decellularization for generating laryngotracheoesophageal scaffolds, focusing on preservation of extracellular matrix integrity and removal of immunogenic material. Methods Laryngotracheoesophageal complexes were harvested from C57BL/6 mice and processed using either antigen removal or sodium dodecyl sulfate‐based protocols. Scaffolds were analyzed for residual double‐stranded DNA content, collagen preservation, glycosaminoglycan retention, and ultrastructural integrity via histology, quantitative image analysis, and scanning electron microscopy. Results Both antigen removal and sodium dodecyl sulfate protocols achieved effective decellularization, with comparable dsDNA removal relative to native controls ( p = 0.001; p < 0.001). Antigen removal scaffolds demonstrated better collagen preservation compared to sodium dodecyl scaffolds, which exhibited marked collagen depletion (Muscle: Collagen I, p < 0.001; Collagen III, p < 0.01; Cartilage: Collagen I, p < 0.05; Collagen III, p < 0.01). Both antigen removal and sodium dodecyl sulfate groups showed significant glycosaminoglycan depletion compared with controls ( p < 0.001). Scanning electron microscopy confirmed superior ultrastructural preservation in antigen removal‐treated scaffolds, characterized by intact fibrillar architecture and lacunar morphology, while sodium dodecyl sulfate scaffolds demonstrated collapsed lacunae and irregular extracellular matrix organization. Conclusion Antigen removal processing generates laryngotracheoesophageal scaffolds with enhanced extracellular matrix preservation compared with conventional sodium dodecyl sulfate decellularization, while maintaining equivalent levels of antigen elimination. Retention of collagen and ultrastructure suggests antigen removal scaffolds may provide superior biomechanical and biologic performance for laryngeal tissue engineering. Although glycosaminoglycan depletion remains a limitation in both approaches, antigen removal scaffolds represent a promising pathway toward clinically translatable alternatives to immunosuppression‐dependent laryngotracheoesophageal repair. Level of Evidence Preclinical.

Comparative analysis of fibrin sealant and recombinant thrombin hydrogels reveals distinct microarchitectures and cellular responses, emphasizing recombinant thrombin’s potential to enhance cellular activity and enable vesicle delivery.

Abstract Recent guidelines by the American Society of Clinical Oncologists recommend that obese individuals receive chemotherapy based on their actual body weight (ABW) without dose reduction. Contrary to prior reports, our own data demonstrate that ABW-dosed chemotherapy or immunotherapy is as effective and well tolerated by obese mice as by lean mice. Nonetheless, obese mice develop significantly greater weight loss in a dose-dependent manner during the entire period that they receive therapy, with corresponding quantifiable reductions in visceral fat depots. This disparity is not explained by altered food intake, as both lean and obese mice experience less than a week of anorexia which does not recur after Cycle 1 of treatment. Furthermore, malabsorption is absent. These observations are relevant to multiple classes of chemo agents. Altered pharmacokinetics of chemotherapy agents in adipose tissue have been reported, yet the pharmacodynamics of obesity remain speculative. Fasting blood glucose monitoring demonstrates glucose level variances which are temporally linked to treatment, rendering it likely that chemotherapy and immunotherapy provoke adipose tissue lipolysis, or alternatively cytoreduction or immunomodulation of adipocyte progenitor cells. Understanding these effects could contribute to improved treatment regimens in the setting of obesity.

Abstract Chronic inflammation associated with aging is termed inflamm-aging. It manifests as a rise in many proinflammatory mediators and contributes to a decline in immune function. Unregulated inflammasome activation initiates an inappropriate inflammatory response. It is particularly imperative to understand inflammasome dysregulation in the elderly (&gt;65 yrs), since it is a likely basis of immune dysfunction. Analyses of freshly isolated memory CD4+ and CD8+ splenic T cells demonstrated that even without further activation, inflammasome genes were already significantly up-regulated in old mice compared to young, including factors critical to myeloid-derived suppressor cell (MDSC) expansion including S100a8, S100a9, IL-1β, IL-13 and IL-6. A corresponding 2-3 fold increase in CD11b+Gr1+cells was observed in the spleens of old naïve mice compared to young. Importantly, cells with the CD11b+Gr1+ phenotype from old mice, unlike young, were functionally MDSCs and suppressed T cell proliferation. Therefore, the immunosuppressive environment of the tumor-bearing host also appears to be operative in aging, even in the absence of tumor. We hypothesize that constituitive activation of inflammasome complex results in a chronic inflammatory state, altering immune responses in the elderly similarly to the tumor-bearing state. Preemptive reversal of inflammasome-induced MDSCs may enhance T cell immunosurveillance in the elderly, a population with a heightened susceptibility to malignancy.

The lamina propria within the vocal fold (VF) is a complex multi-layered tissue that increases in stiffness from the superficial to deep layer, where this characteristic is crucial for VF sound production. Tissue engineered scaffolds designed for VF repair must mimic the biophysical nature of the native vocal fold and promote cell viability, cell spreading, and vibration with air flow. In this study, we present a unique tri-layered, partially-degradable hydrogel scaffold that mimics the multi-layered structure of the VF lamina propria. Using thiol-norbornene photochemistry, tri-layered hydrogel scaffolds were fabricated via layer-by-layer stacking with increasing polymer concentration from the top to middle to deep layer. Mechanical analysis confirmed hydrogel modulus increased with increasing polymer concentration. Partially-degradable hydrogels promoted high cell viability and cell spreading in 3D as assessed via live/dead and cytoskeleton staining, respectively. Importantly, partially-degradable hydrogels maintained some degree of the 3D polymer network following protease exposure, while still enabling encapsulated cells to remodel their local environment via protease secretion. Finally, the tri-layered hydrogel scaffold successfully vibrated and produced sound in proof-of-concept air flow studies. This work represents a critical first step towards the design of a multi-layered, hydrogel scaffold for vocal fold tissue engineering.

Objectives/HypothesisDevelop a patient‐specific tissue engineered construct for laryngeal reconstruction following a partial laryngectomy.Study DesignBench and animal research.MethodsA construct made from a porous polyethylene scaffold shaped in a canine‐specific configuration and seeded with autologous canine adipose‐derived stem cells in fibrin glue was implanted in a canine following a partial laryngectomy. After 1 year, the construct was first evaluated in vivo with high‐speed imaging and acoustic–aerodynamic measures. It was then explanted and evaluated histologically.ResultsThe canine study at 1 year revealed the construct provided voicing (barking) with acoustic and aerodynamic measures within normal ranges. The canine was able to eat and breathe normally without long‐term support. The construct was integrated with epithelialization of all areas except the medial portion of the vocal fold structure. No anti‐infective agents were needed after the standard perioperative medications were completed.ConclusionThis study provided a successful first step toward developing a patient‐specific composite construct for patients undergoing partial laryngectomies.Level of EvidenceNA Laryngoscope, 132:S1–S11, 2022

ObjectiveThe study aims to demonstrate the reproducibility and feasibility of creating a hemilaryngeal model with a medialized vocal fold (VF) using 3‐dimensional (3D) modeling techniques in both healthy larynges and those affected by cancer.Study DesignThree‐dimensional modeling of human larynges.SettingTertiary academic referral center and regenerative medicine laboratory.Subjects and MethodsComputed tomography (CT) scans from 10 healthy control and 10 patients with laryngeal cancer were segmented and imported into 3D modeling software. The larynx was cut sagittally to create a hemilaryngeal model and the vocal fold medialized. Measurements were taken from the CT and 3D model data and compared.ResultsAll control modeling data closely matched the CT data and were not statistically different from each other. There was a significant correlation between subglottic anteroposterior diameter and VF length (r2 = 0.78, P =. 0008), and it may be a valuable tool to infer true VF dimension in cases where disruption has occurred. The modeling data from patients with cancer did not show statistical difference to the control data, showing that accurate modeling can also be achieved in patients with laryngeal cancer.ConclusionCT scan‐based 3D modeling of the larynx and VF is possible and reproducible. The results closely match those previously reported in the literature and can also be replicated in cases with laryngeal cancer. This study paves the way for future de novo fabricated laryngeal scaffolds that can be synthesized using 3D printers and tailored to meet surgical demands.