Master of Science in Biomedical Engineering, Cleveland State University, 2023, Washkewicz College of Engineering

Tendons serve to attach muscles to bones, and are dense structures composed of fibers. Tendon injuries, as well as tendinopathies, in which a tendon is overused or has been degenerated due to sport injuries or age, are a large problem for many adult patients and account for about 30% of musculoskeletal diseases. Around 33 million musculoskeletal injuries have been reported per year in the United States alone, 50% of which involve tendon and ligament injuries. In American healthcare, only the flexor tendon lacerations sustain estimated costs of anywhere between $240.8 to $409.1 million per year. Having a slow metabolism, tendon tissue needs a substantial period to redevelop enough strength after injury. In most of the cases, tendon tissue does not have full functional recovery because of low regeneration capacity and scar tissue formation. Therefore, the healing of tendon injuries is a significant and clinically challenging problem requiring an urgent need to find alternative and cost-effective treatments. To address this problem, a combinatorial approach involving synergetic use of a 3- dimensional (3D) scaffold system with adult mesenchymal stem cells (MSCs) and locally applied electrical stimulation (ES) was used to produce bioactive extracellular vesicles (EVs) as novel therapeutic tools to enhance tendon regeneration. For this purpose, whey protein isolate (WPI)-based 3D scaffolds were developed to provide favorable microenvironment for MSCs attachment and growth. Conductive graphene and biodegradable Polylactic Acid (PLA) based flexible electronic coil was integrated to the 3D WPI scaffold to provide wireless ES of MSCs and modulate EVs secretion. The isolated EVs were characterized and applied to primary tenocyte cells to evaluate the regenerative activity. The results indicated that the isolated EVs, as well as applied ES, promoted the regeneration capacity of tenocyte cells in vitro and promoted the expression of tendon markers. This re (open full item for complete abstract)

Committee: Metin Uz (Committee Chair); Prabaha Sikder (Committee Member); Chandra Kothapalli (Committee Member) Subjects: Biomedical Engineering; Biomedical Research

Master of Science, The Ohio State University, 2024, Veterinary Clinical Sciences

Equine superficial digital flexor tendon (SDFT) injuries heal primarily through fibrosis, in part due to persistent macrophage-induced inflammation throughout the healing process. Despite the low retention and short life of bone marrow mesenchymal stem cells (BM-MSC) following intratendinous injections, benefits including reducing local inflammation, improving histological structure, and reducing tendon re-injury rates, in experimental and naturally occurring equine tendonitis, are well-known. Extracellular vesicle (EV) release at the healing milieu is one of the speculated mechanisms for the immunomodulatory and anti-fibrotic benefits of BM-MSC. EVs are secreted membrane-bound cytokine, growth factor and mRNA/miRNA cargo reflective of the parent cells and facilitate intercellular communication. From a clinical standpoint, EVs circumvent donor site morbidity, time lag for culture expansion and allogenic cell-related immunogenicity limitations of BM-MSC and comprise an ‘off-the-shelf' cell-free therapy for equine tendon injuries.    This research investigates the mitogenic, anti-inflammatory, and extracellular matrix (ECM) remodeling effects of equine BM-MSC-derived EVs (BM-EV) on tenocytes cultured on acellular SDFT matrix. We hypothesized that (1) BM-EV increases the adherence and proliferation of tenocytes during culture on acellular SDFT matrix, and (2) BM-EV modulates inflammation and stimulates extracellular matrix (ECM) remodeling during direct (cell-to-cell contact) tenocyte-macrophage co-culture on acellular SDFT matrix.   Undifferentiated (7-day basal media), pro-inflammatory (6-day GM-CSF and 24-hour LPS+IFN-γ priming) and regulatory (6-day basal media and 24-hour IL-4+IL-10 priming) macrophages were generated from peripheral blood CD14+ monocytes. Passage 3 tenocytes (CD90+105+27-45-) were isolated from freshly euthanized cadaveric forelimb mid-metacarpal SDFT via collagenase I digestion and monolayer culture.   BM-EV were isolated via ultra (open full item for complete abstract)

Committee: Sushmitha Durgam (Advisor); Alison Gardner (Committee Member); Laura Hostnik (Committee Member); Amit Sharma (Committee Member) Subjects: Comparative; Medicine

Master of Science, The Ohio State University, 2023, Biomedical Sciences

Injury to the superficial digital flexor tendon (SDFT) accounts for up to half of the musculoskeletal injuries in Thoroughbred racehorses and is a common reason for retirement. There is growing evidence that SDFT injuries are the result of cumulative microdamage from racehorses working at high speeds that place the tendon under maximal tensile capacity, rather than a single traumatic event. Current therapies consisting of prolonged rest, rehabilitation, and intralesional biologics aim to improve healing of the SDFT, but reduced elasticity of the ‘healed' tendon results in re-injury rates of up to 50%. Therefore, documenting flexor tendon adaptation to athletic training and delineating the mechanisms leading to SDFT injury in racing Thoroughbreds is crucial for reducing tendon injury incidence and associated loss. The objectives of this research are two-fold. First, to assess changes in SDFT hierarchical structure and elastin in mid-metacarpal SDFTs obtained from 2-, 3-, and 4year-old training/racing Thoroughbred cadaver distal limbs. Second, to determine if the biomechanical properties of SDFT are altered by athletic training. Distal forelimb SDFTs were collected from 2-, 3-, and 4-year-old Thoroughbred racehorses (N=50) within 48 hours of death or euthanasia for reasons other than SDFT injuries and that were necropsied through the California Animal Health and Food Safety Laboratory System (CAHFS). A randomly chosen forelimb SDFT was processed for histology and whole tendon biochemical quantification. The contralateral forelimb SDFT was stored at -20°C for whole tendon biomechanical testing. For histological assessment, cryopreserved sections from 1-cm mid-metacarpal SDFT segments were used for elastin immunostaining, prior to concurrent immunofluorescence and second harmonic generation (SHG) confocal microscopy. Stained, paraffin-embedded, histological sections were used for fascicle cross-sectional area (CSA) and interfascicular matrix (IFM) measurements using (open full item for complete abstract)

Committee: Sushmitha Durgam BVSc, MS, PhD (Advisor); Rebecca Urion (Committee Member); Hilary Rice DVM, MS (Committee Member) Subjects: Animal Sciences; Biomechanics; Biomedical Research