Fibroblasts are stromal cells ubiquitously distributed in the body of nearly every organ tissue. These cells were previously considered to be “passive cells”, solely responsible for ensuring the turnover of the extracellular matrix (ECM). However, their versatility, including their ability to switch phenotypes in response to tissue injury and dynamic activity in the maintenance of tissue specific homeostasis and integrity have been recently revealed by the innovation of technological tools such as genetically modified mouse models and single cell analysis. These highly plastic and heterogeneous cells equipped with multifaceted functions including the regulation of angiogenesis, inflammation as well as their innate stemness characteristics, play a central role in the delicately regulated process of wound healing. Fibroblast dysregulation underlies many chronic conditions, including cardiovascular diseases, cancer, inflammatory diseases, and diabetes mellitus (DM), which represent the current major causes of morbidity and mortality worldwide. Diabetic foot ulcer (DFU), one of the most severe complications of DM affects 40 to 60 million people. Chronic non-healing DFU wounds expose patients to substantial sequelae including infections, gangrene, amputation, and death. A complete understanding of the pathophysiology of DFU and targeting pathways involved in the dysregulation of fibroblasts are required for the development of innovative new therapeutic treatments, critically needed for these patients.

Objective: Here, we report a new method to increase the therapeutic potential of mesenchymal stem/stromal cells (MSCs) for ischemic wound healing. We tested biological effects of MSCs modified with E-selectin, a cell adhesion molecule capable of inducing postnatal neovascularization, on a translational murine model. Background: Tissue loss significantly worsens the risk of extremity amputation for patients with chronic limb-threatening ischemia. MSC-based therapeutics hold major promise for wound healing and therapeutic angiogenesis, but unmodified MSCs demonstrate only modest benefits. Methods: Bone marrow cells harvested from FVB/ROSA26Sor^mTmG donor mice were transduced with E-selectin-green fluorescent protein (GFP)/AAV-DJ or GFP/AAV-DJ (control). Ischemic wounds were created via a 4 mm punch biopsy in the ipsilateral limb after femoral artery ligation in recipient FVB mice and subsequently injected with phosphate-buffered saline or 1×10⁶ donor MSC^GFP or MSC^{E-selectin-GFP}. Wound closure was monitored daily for 7 postoperative days, and tissues were harvested for molecular and histologic analysis and immunofluorescence. Whole-body DiI perfusion and confocal microscopy were utilized to evaluate wound angiogenesis. Results: Unmodified MSCs do not express E-selectin, and MSC^{E-selectin-GFP} gain stronger MSC phenotype yet maintain trilineage differentiation and colony-forming capability. MSC^{E-selectin-GFP} therapy accelerates wound healing compared with MSC^GFP and phosphate-buffered saline treatment. Engrafted MSC^{E-selectin-GFP} manifest stronger survival and viability in wounds at postoperative day 7. Ischemic wounds treated with MSC^{E-selectin-GFP} exhibit more abundant collagen deposition and enhanced angiogenic response. Conclusions: We establish a novel method to potentiate regenerative and proangiogenic capability of MSCs by modification with E-selectin/adeno-associated virus. This innovative therapy carries the potential as a platform worthy of future clinical studies.

Objective: This study focuses on dose–response investigation using a codon-optimized and de novo–synthesized E-Selectin/AAV2 (E-Sel/AAV2) vector in preparation for Investigational New Drug enabling of subsequent clinical studies. Background: Gene therapy is a potential solution for patients suffering from chronic limb-threatening ischemia. Understanding the dose for effective gene delivery is crucial for future Investigational New Drug–enabling studies. Methods: Expression of the codon-optimized E-Selectin gene was assessed by flow cytometry following in vitro cell transfection assay and RT-qPCR for murine limbs injected in vivo with AAV-m-E-Selectin (E-Sel/AAV2). Dose–response studies involved 3 cohorts of FVB/NJ mice (n=6/group) with escalating log doses of E-Selectin/AAV2 injected intramuscularly in divided aliquots, ranging from 2 × 10⁹ VG to 2 × 10¹¹ VG, into ischemic limbs created by left femoral artery/vein ligation/excision and administration of nitric oxide synthase inhibitor, L-NAME. Limb perfusion, extent of gangrene free limb, functional limb recovery, and therapeutic angiogenesis were assessed. Results: Codon-optimized E-Sel/AAV2 gene therapy exhibits a superior expression level than WT E-Sel/AAV2 gene therapy both in vitro and in vivo. Mice treated with a high dose (2 × 10¹¹ VG) of E-Sel/AAV2 showed significantly improved perfusion indices, lower Faber scores, increased running stamina, and neovascularization compared with lower doses tested with control groups, indicating a distinct dose-dependent response. No toxicity was detected in any of the animal groups studied. Conclusions: E-Sel/AAV2 Vascular Regeneration Gene Therapy holds promise for enhancing the recovery of ischemic hindlimb perfusion and function, with the effective dose identified in this study as 2 × 10¹¹ VG aliquots injected intramuscularly.

Purpose: Coronavirus disease 2019 (COVID-19) has underscored how ill-prepared healthcare systems are for mass casualty events (MCEs,) especially as MCEs increase worldwide. We hypothesized that resident physicians (RPs) across multiple specialties are underprepared for MCE. Methods: Two similar surveys were conducted to assess awareness of disaster plans (DPs) and individual’s roles and responsibilities therein. Initially, we surveyed exclusively trainees who are trauma team members (TTMs,) including physician assistants (PAs), residents from emergency medicine (EMRs) and general surgery (GSRs.) Subsequently, we surveyed multi-specialty RPs, except GSRs and EMRs, and their program directors/associate program directors (PDs/APDs.) RPs’ awareness, knowledge of, and confidence in hospital MCE response plans were assessed, and barriers encountered were queried. Data were consolidated except with respect to PDs/APDs, who were queried only in the second survey. The Fisher exact test for multiple-group comparisons was used. Alpha = 0.05. Results: For the first survey, the response rate was 74% (123/166), whereas 34% (129/380) responded to the second survey. Combined, the response rate was 46% (252/546.) Considering the RPs only for the two surveys combined, 103 (53%) respondents reported no awareness of institutional MCE response plans, 73% (n = 143) did not know/were unsure whether they were expected to contact someone, and 68% (n = 134) reported no formal MCE/disaster management (DM) training over the prior year. Additionally, the median response reported for level of knowledge of the MCE response plan among all RPs was “not at all,” with a significant difference observed between those aware of the plan and those who were not (p < 0.001). The median response reported for confidence level of RPs in MCE/DM training, excluding GSRs and EMRs (TTMs,) was “not at all,” with significant differences between surgical and non-surgical specialty RPs (p = 0.031), and between junior and senior RPs (p = 0.027). PDs/APDs (n = 12) reported “time” as the main barrier to implementation. Conclusions: RPs across all surveyed specialties reported low levels of knowledge and minimal training regarding MCE/DM. Incorporation of MCE/DM preparedness into residency training in all specialties involving direct patient care is essential. Curricular restructuring will be required for meaningful participation of RPs in MCEs.

Objective: Targeting of healthcare infrastructures in Ukraine has served as a tactical warfare strategy. The goal of the Global Surgical and Medical Support Group (GSMSG) is to provide sustainable, high quality medical and surgical care in war zones. Interventions: GSMSG deployed United States (US) Special Operations veterans and highly specialized licensed medical experts. Training of Ukrainian civilians was implemented. Results: Over 20,000 Ukrainians trained and over 100 major surgeries performed with assistance of world experts. Specialized medical equipment was also provided. Conclusion: GSMSG lays the groundwork for effective, high quality, and sustainable surgical interventions into a nation in conflict.