Browsing by Author "Brookes, Sarah"

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    Eliciting and Characterizing Porcine Vocalizations: When Pigs Fly
    (Elsevier, 2022-04-30) Zhang, Lujuan; Fujiki, Robert Brinton; Brookes, Sarah; Calcagno, Haley; Awonusi, Oluwaseyi; Kluender, Keith; Berry, Kevin; Venkatraman, Anumitha; Maulden, Amanda; Sivasankar, M. Preeti; Voytik-Harbin, Sherry; Halum, Stacey; Otolaryngology -- Head and Neck Surgery, School of Medicine
    Background/Objectives: While voice-related therapeutic interventions are often researched preclinically in the porcine model, there are no well-established methods to induce porcine glottic phonation. Described approaches such as training animals to phonate for positive reinforcement are time-consuming and plagued by inherent variability in the type of phonation produced and contamination of background noise. Thus, a reliable method of assessing glottic phonation in the porcine model is needed. Methods: In this study, we have created a novel pulley-based apparatus with harness for “pig-lifting” with surrounding acoustic insulation and high-directional microphone with digital recorder for recording phonation. Praat and Matlab were used to analyze all porcine vocalizations for fundamental frequency (F0), intensity, duration of phonation and cepstral peak prominence (CPP). Glottic phonation was detected using F0 (≥ 2000 hz), duration (≥.3 seconds) and researcher perceptual judgment. Partial-glottic phonations were also analyzed. Reliability between researcher judgment and acoustic measures for glottic phonation detection was high. Results: Acoustic analysis demonstrated that glottic and partial-glottic phonation was consistently elicited, with no formal training of the minipigs required. Glottic vocalizations increased with multiple lifts. Glottic phonation continued to be elicited after multiple days but became less frequent. Glottic and partial-glottic phonations had similar CPP values over the 6 experimental days. Conclusion: Our cost-effective, reliable method of inducing and recording glottic phonation in the porcine model may provide a cost effective, preclinical tool in voice research.
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    Engineered collagen polymeric materials create noninflammatory regenerative microenvironments that avoid classical foreign body responses
    (Royal Society of Chemistry, 2023) Morrison, Rachel A.; Brookes, Sarah; Puls, Theodore J.; Cox, Abigail; Gao, Hongyu; Liu, Yunlong; Voytik-Harbin, Sherry L.; Medical and Molecular Genetics, School of Medicine
    The efficacy and longevity of medical implants and devices is largely determined by the host immune response, which extends along a continuum from pro-inflammatory/pro-fibrotic to anti-inflammatory/pro-regenerative. Using a rat subcutaneous implantation model, along with histological and transcriptomics analyses, we characterized the tissue response to a collagen polymeric scaffold fabricated from polymerizable type I oligomeric collagen (Oligomer) in comparison to commercial synthetic and collagen-based products. In contrast to commercial biomaterials, no evidence of an immune-mediated foreign body reaction, fibrosis, or bioresorption was observed with Oligomer scaffolds for beyond 60 days. Oligomer scaffolds were noninflammatory, eliciting minimal innate inflammation and immune cell accumulation similar to sham surgical controls. Genes associated with Th2 and regulatory T cells were instead upregulated, implying a novel pathway to immune tolerance and regenerative remodeling for biomaterials.
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    Impact of Needle Selection on Survival of Muscle-Derived Cells When Used for Laryngeal Injections
    (Longdom Publishing, 2023) Awonusi, Oluwaseyi; Harbin, Zachary J.; Brookes, Sarah; Zhang, Lujuan; Kaefer, Samuel; Morrison, Rachel A.; Newman, Sharlé; Voytik-Harbin, Sherry; Halum, Stacey; Otolaryngology -- Head and Neck Surgery, School of Medicine
    Objective: To describe how differing injector needles and delivery vehicles impact Autologous Muscle-Derived Cell (AMDC) viability when used for laryngeal injection. Methods: In this study, adult porcine muscle tissue was harvested and used to create AMDC populations. While controlling cell concentration (1 × 107 cells/ml), AMDCs including Muscle Progenitor Cells (MPCs) or Motor Endplate Expressing Cells (MEEs) were suspended in either phosphate-buffered saline or polymerizable (in-situ scaffold forming) type I oligomeric collagen solution. Cell suspensions were then injected through 23- and 27-gauge needles of different lengths at the same rate (2 ml/min) using a syringe pump. Cell viability was measured immediately after injection and 24- and 48-hours post-injection, and then compared to baseline cell viability prior to injection. Results: The viability of cells post-injection was not impacted by needle length or needle gauge but was significantly impacted by the delivery vehicle. Overall, injection of cells using collagen as a delivery vehicle maintained the highest cell viability. Conclusion: Needle gauge, needle length, and delivery vehicle are important factors that can affect the viability of injected cell populations. These factors should be considered and adapted to improve injectable MDC therapy outcomes when used for laryngeal applications.
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    Laryngeal Reconstruction Using Tissue-Engineered Implants in Pigs: A Pilot Study
    (Wiley, 2021-10) Brookes, Sarah; Zhang, Lujuan; Puls, Theodore J.; Kincaid, John; Voytik-Harbin, Sherry; Halum, Stacey; Otolaryngology -- Head and Neck Surgery, School of Medicine
    Objective/hypothesis: There are currently no treatments available that restore dynamic laryngeal function after hemilaryngectomy. We have shown that dynamic function can be restored post hemilaryngectomy in a rat model. Here, we report in a first of its kind, proof of concept study that this previously published technique is scalable to a porcine model. Study design: Animal study. Methods: Muscle and fat biopsies were taken from three Yucatan minipigs. Muscle progenitor cells (MPCs) and adipose stem cells (ASCs) were isolated and cultured for 3 weeks. The minipigs underwent a left laterovertical partial laryngectomy sparing the left arytenoid cartilage and transecting the recurrent laryngeal nerve. Each layer was replaced with a tissue-engineered implant: 1) an acellular mucosal layer composed of densified Type I oligomeric collagen, 2) a skeletal muscle layer composed of autologous MPCs and aligned oligomeric collagen differentiated and induced to express motor endplates (MEE), and 3) a cartilage layer composed of autologous ASCs and densified oligomeric collagen differentiated to cartilage. Healing was monitored at 2 and 4 weeks post-op, and at the 8 week study endpoint. Results: Animals demonstrated appropriate weight gain, no aspiration events, and audible phonation. Video laryngoscopy showed progressive healing with vascularization and re-epithelialization present at 4 weeks. On histology, there was no immune reaction to the implants and there was complete integration into host tissue with nerve and vascular ingrowth. Conclusions: This pilot study represents a first in which a transmural vertical partial laryngectomy was performed and successfully repaired with a customized, autologous stem cell-derived multi-layered tissue-engineered implant.
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    Use of autologous adipose-derived mesenchymal stem cells for creation of laryngeal cartilage
    (Wiley, 2018-04) Zhang, Hongji; Voytik-Harbin, Sherry; Brookes, Sarah; Zhang, Lujuan; Wallace, Joseph; Parker, Noah; Halum, Stacey; Biomedical Engineering, School of Engineering and Technology
    OBJECTIVES/HYPOTHESIS: Adipose-derived mesenchymal stem cells (ASCs) are an exciting potential cell source for tissue engineering because cells can be derived from the simple excision of autologous fat. This study introduces a novel approach for tissue-engineering cartilage from ASCs and a customized collagen oligomer solution, and demonstrates that the resultant cartilage can be used for laryngeal cartilage reconstruction in an animal model. STUDY DESIGN: Basic science experimental design. METHODS: ASCs were isolated from F344 rats, seeded in a customized collagen matrix, and cultured in chondrogenic differentiation medium for 1, 2, and 4 weeks until demonstrating cartilage-like characteristics in vitro. Large laryngeal cartilage defects were created in the F344 rat model, with the engineered cartilage used to replace the cartilage defects, and the rats followed for 1 to 3 months. Staining examined cellular morphology and cartilage-specific features. RESULTS: In vitro histological staining revealed rounded chondrocyte-appearing cells evenly residing throughout the customized collagen scaffold, with positive staining for cartilage-specific markers. The cartilage was used to successfully repair large cartilaginous defects in the rat model, with excellent functional results. CONCLUSIONS: This study is the first study to demonstrate, in an animal model, that ASCs cultured in a unique form of collagen oligomer can create functional cartilage-like grafts that can be successfully used for partial laryngeal cartilage replacement.