Browsing by Author "Kulwatno, Jonathan"

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    A Two-Stage Approach Integrating Provisional Biomaterial-Mediated Stabilization Followed by a Definitive Treatment for Managing Volumetric Muscle Loss Injuries
    (MDPI, 2024-06-06) Clark, Andrew R.; Kulwatno, Jonathan; Kanovka, Sergey S.; Klarmann, George J.; Hernandez, Claudia E.; Natoli, Roman M.; McKinley, Todd O.; Potter, Benjamin K.; Dearth, Christopher L.; Goldman, Stephen M.; Orthopaedic Surgery, School of Medicine
    Treatment of volumetric muscle loss (VML) faces challenges due to its unique pathobiology and lower priority in severe musculoskeletal injury management. Consequently, a need exists for multi-stage VML treatment strategies to accommodate delayed interventions owing to comorbidity management or prolonged casualty care in combat settings. To this end, polyvinyl alcohol (PVA) was used at concentrations of 5%, 7.5%, and 10% to generate provisional muscle void fillers (MVFs) of varying stiffness values (1.125 kPa, 3.700 kPa, and 7.699 kPa) to stabilize VML injuries as part of a two-stage approach. These were implanted into a rat model for a duration of 4 weeks, then explanted and either left untreated (control) or treated through minced muscle grafting (MMG). Additional benchmarks included acute MMG and unrepaired groups. At the MVF explant, the 7.5% PVA group exhibited superior neuromuscular function compared to the 5% and 10% PVA groups, the least fibrosis, and the largest median myofiber size among all groups at the 12-week endpoint. Despite the 7.5% PVA’s superiority amongst the two-stage treatment groups, neuromuscular function was neither improved nor impaired relative to acute treatment benchmarks. This suggests that the future success of a two-stage VML treatment strategy will necessitate a more effective definitive intervention.
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    In situ forming biomaterials as muscle void fillers for the provisional treatment of volumetric muscle loss injuries
    (Elsevier, 2023-09-02) Clark, Andrew; Kulwatno, Jonathan; Kanovka, Sergey S.; McKinley, Todd O.; Potter, Benjamin K.; Goldman, Stephen M.; Dearth, Christopher L.; Orthopaedic Surgery, School of Medicine
    Volumetric muscle loss (VML) represents a devastating extremity injury which leads to chronic functional deficits and disability and is unrecoverable through normal healing pathways. When left untreated, the VML pathophysiology creates many challenges towards successful treatment, such as altered residual muscle architecture, excessive fibrosis, and contracture(s). As such, innovative approaches and technologies are needed to prevent or reverse these adverse sequelae. Development of a rationally designed biomaterial technology which is intended to be acutely placed within a VML defect – i.e., to serve as a muscle void filler (MVF) by maintaining the VML defect – could address this clinical unmet need by preventing these adverse sequelae as well as enabling multi-staged treatment approaches. To that end, three biomaterials were evaluated for their ability to serve as a provisional MVF treatment intended to stabilize a VML defect in a rat model for an extended period (28 days): polyvinyl alcohol (PVA), hyaluronic acid and polyethylene glycol combination (HA + PEG), and silicone, a clinically used soft tissue void filler. HA + PEG biomaterial showed signs of deformation, while both PVA and silicone did not. There were no differences between treatment groups for their effects on adjacent muscle fiber count and size distribution. Not surprisingly, silicone elicited robust fibrotic response resulting in a fibrotic barrier with a large infiltration of macrophages, a response not seen with either the PVA or HA + PEG. Taken together, PVA was found to be the best material to be used as a provisional MVF for maintaining VML defect volume while minimizing adverse effects on the surrounding muscle.