A review of animal models from 2015 to 2020 for preclinical chronic wounds relevant to human health.

SIGNIFICANCE: Chronic wounds fail to heal in a timely manner and exhibit sustained inflammation with slow tissue repair and remodelling. They decrease mobility and quality of life, and remain a major clinical challenge in the long-term care of many patients, affecting 6.5 million individuals annually in the U.S., decreasing mobility and quality of life. Treatment costs are a major burden on the U.S. healthcare system, totalling between $25 and $100 billion annually. Chronic wound severity depends upon several factors such as comorbidities, severity of tissue damage, infection and presence of necrosis and vary greatly in their healing mechanisms. In vivo animal models are critical for studying healing pathways of chronic wounds and seek to replicate clinical factors for trials of topical, systemic, and device-based therapeutics. This comprehensive review discusses murine, rat, lapine, canine, feline and porcine models of chronic wounds. RECENT ADVANCES: Foundational chronic wound models for several species are discussed together with refinements and advances in the time period between 2015 and 2020 which have the potential for broad utility in investigating biological and device-based wound treatment therapies for human health. CRITICAL ISSUES: Chronic wounds fail to heal in a timely manner and have differing aetiologies, rendering no single in vivo animal model universally applicable. FUTURE DIRECTIONS: Further studies are required to develop clinically relevant chronic wound animal model which reflect the clinical reality of the various influences of age, disease, comorbidities and gender on delayed healing and enhance understanding of the biological processes of human wound healing.

Wheelchair Mobility-Related Injuries Due to Inadvertent Lower Extremity Displacement on Footplates: Analysis of the FDA MAUDE Database From 2014 to 2018.

OBJECTIVES: The aims of the study were to assess reports of wheelchair mobility-related injuries from inadvertent lower extremity displacement (ILED) on footplates, which were submitted to the Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database during 2014-2018, characterize injury types, and evaluate MAUDE data quality. METHODS: A systematic MAUDE database review was performed. Annual reports were searched using keywords: (a) "power wheelchair" and "injury" and (b) "mechanical (also known as manual) wheelchair" and "injury." Reports related to injuries from ILED on the footplate were reviewed. RESULTS: Reports of 1075 wheelchair injuries were found across the review period. Twenty nine (3%) met our inclusion criteria. The most common source of reports was "manufacturer." The wheelchair was unavailable for evaluation in 55.17% of reports. Manufacturers' submission dates (number of days that passed after they were notified) ranged from 3 to 159. Reported injuries decreased by 60% from 2014 to 2018. The end user used a power wheelchair for all but one report. The most common injuries were single fractures, multiple fractures, wounds/cuts/infections, and amputations (in order of incidence). The most common mechanism was the foot slipping off the footplate during wheelchair mobility. CONCLUSIONS: We observed inherent weaknesses in the MAUDE database reporting process and a concerning level of reporting bias. Although there were limited reports of injuries related to ILED on the footplate during wheelchair mobility, the injuries reported were significant. More standardized reporting of the mechanism and impact of these injuries is needed to better inform wheelchair design, prescription, and patient/family education.

Biomarkers for recurrent pressure injury risk in persons with spinal cord injury.

Objective: To investigate potential linkages between pressure injury (PrI) recurrence following spinal cord injury (SCI) and muscle-based and circulatory biomarkers, specifically fatty metabolites and inflammatory cytokines. Design: Observational study. Setting: Tertiary Care Center. Participants: 30 individuals with complete or incomplete SCI. Study participants either had never developed a PrI (Group I) or had a history of recurrent PrI (Group II). Interventions: Not applicable. Outcome Measures: Gluteal muscle histology, immunohistochemistry, muscle-based and circulatory fatty metabolites and inflammatory cytokines. Results: Gluteal intramuscular adipose tissue (IMAT) was greater than 15% in most Group II (83%) individuals. Muscle tissue histology confirmed intramuscular structural differences. Fatty acid binding protein 4 (FABP4) and fatty acid binding protein 3 (FABP3) were reliably detected in muscle and blood and significantly correlated with IMAT (P < 0.001). FABP4 was significantly higher in Group II muscle and blood (P < 0.05). FABP3 was significantly higher in Group I muscle (P < 0.05). Circulatory FABP3 levels were lower for Group I. Inflammatory biomarkers were more reliably detected in blood. Colony-Stimulating Factor-1 was slightly higher in Group II muscle. Circulatory interleukin-13 was significantly higher (P < 0.01) in Group I. Vascular endothelial growth factor (VEGF-A) was significantly increased (P < 0.05) in Group I muscle and blood. Conclusion: Identifying individuals with SCI at highest risk for recurrent PrI may impact patient management. IMAT content evaluation illustrates that muscle quality is a key biomarker. Low circulatory inflammatory biomarker expression potentially limits clinical significance for between group differences. Circulatory levels of FABP4 hold great potential as a recurrent PrI risk biomarker.