Benefits of Aerosolized, Point-of-care, Autologous Skin Cell Suspension (ASCS) for the Closure of full Thickness Wounds from Thermal and Non-Thermal Causes: Learning Curves from the first 50 Consecutive cases at an Urban, Level 1 Trauma Center.

OBJECTIVE: To determine the utility of Autologous Skin Cell Suspension (ASCS) in closing full-thickness (FT) defects from injury and infection. SUMMARY BACKGROUND DATA: Although ASCS has documented success in closing partial-thickness burns, far less is known about the efficacy of ASCS in FT defects. METHODS: Fifty consecutive patients with FT defects (burn 17, necrotizing infection 13, crush 7, degloving 5, other 8) underwent closure with the bilayer technique of 3:1 widely-meshed, thin, split-thickness skin graft and 80:1 expanded ASCS. End points were limb salvage rate, donor site reduction, operative and hospital throughput, incidence of complications, and re-epithelialization by 4, 8, and 12 weeks. RESULTS: Definitive wound closure was achieved in 76%, 94%, and 98% of patients, at 4, 8, and 12 weeks, respectively. Limb salvage occurred in 42/43 patients (10 upper, 33 lower extremities). Mean area grafted was 435 cm2; donor site size was 212 cm2, representing a potential reduction of 50%. Mean surgical time was 71 minutes; total OR time was 124 minutes. Mean length-of-stay was 26.4 days; time from grafting to discharge was 11.2 days. 4/50 patients (8%) required 6 reoperations for bleeding (1), breakdown (4), and amputation (1). 4/50 patients (8%) developed hypertrophic scarring, which responded to silicone sheeting (2) and laser resurfacing (2). Mean follow-up was 92.7 days. CONCLUSION: When used for closure of FT wounds, point-of-care ASCS is effective and safe. Benefits include rapid re-epithelialization, high rate of limb salvage, reduction of donor site size and morbidity, and low incidence of hypertrophic scarring.

Outcomes following surgical intervention for acute hemorrhage in severe traumatic brain injury: a review of the National Trauma Data Bank.

OBJECTIVE: Severe traumatic brain injury (TBI) is a public health issue posing significant morbidity and mortality to afflicted patients. While the effect of time to surgery as the primary factor for survival has been extensively studied, long-term dispositional outcomes following intracranial hemorrhage evacuation have not been well described in the literature. Therefore, the aim of this study was to elicit potential prognostic factors in patients presenting with severe TBI that may have a significant impact on discharge disposition. METHODS: The authors searched the National Trauma Data Bank (NTDB) for patients included between 2010 and 2019, solely focusing on those with a Glasgow Coma Scale score ≤ 8, signifying severe TBI, and with associated intracranial hemorrhage treated via surgical intervention. Numerous characteristics were analyzed, including demographics (age, sex, race, ethnicity, payment status), discharge disposition, time to surgery, pupillary response, midline shift (> 5 mm), and postoperative inpatient complications and comorbidities. Disposition included routine discharge to home, discharge to home with home health services (HHSs), discharge to acute inpatient rehabilitation (AIR), discharge to a skilled nursing facility (SNF)/long-term acute care hospital (LTACH), and death. RESULTS: The authors analyzed data on 7308 patients, 69.6% of whom were White and 11.2% of whom were Black. More young Black and Hispanic patients had severe TBI events than their matched elders, whereas more elderly White patients had severe TBI events than their matched younger counterparts. The most common disposition across all ages was SNF/LTACH. Septuagenarians and octogenarians were 12.1 and 21 times more likely, respectively, to die following a severe TBI than their younger counterparts (p < 0.001). Patients aged 18-29 were 1.7 times more likely to be discharged with HHSs (p < 0.001). Minority race/ethnicity groups were less likely to be discharged to AIR. As age increased, a patient's intensive care unit stay increased by 15 days (p < 0.001) and total hospital length of stay increased by 25 days (p < 0.001). CONCLUSIONS: Neurosurgical evacuation of intracranial hemorrhage in severe TBI has variable long-term morbidity. Utilizing the largest collection of trauma data within the United States, the authors present quantitative evidence on discharge disposition. Understanding these tangible points can help neurosurgeons present potential outcomes to patients, promote preventative care, and generate tangible conversations with patients and their family members.

A CRISPR Screen Identifies the Cell Polarity Determinant Crumbs 3 as an Adeno-associated Virus Restriction Factor in Hepatocytes.

Adeno-associated viruses (AAV) are helper-dependent parvoviruses that have been developed into promising gene therapy vectors. Many studies, including a recent unbiased genomic screen, have identified host factors essential for AAV cell entry, but no genome-wide screens that address inhibitory host factors have been reported. Here, we utilize a novel CRISPR screen to identify AAV restriction factors in a human hepatocyte cell line. The major hit from our gain-of-function screen is the apical polarity determinant Crumbs 3 (Crb3). Knockout (KO) of Crb3 enhances AAV transduction, while overexpression exerts the opposite effect. Further, Crb3 appears to restrict AAV transduction in a serotype- and cell type-specific manner. Particularly, for AAV serotype 9 and a rationally engineered AAV variant, we demonstrate that increased availability of galactosylated glycans on the surfaces of Crb3 KO cells, but not the universal AAV receptor, leads to increased capsid attachment and enhanced transduction. We postulate that Crb3 could serve as a key molecular determinant that restricts the availability of AAV glycan attachment factors on the cell surface by maintaining apical-basal polarity and tight junction integrity.IMPORTANCE Adeno-associated viruses (AAVs) have recently emerged at the forefront as gene therapy vectors; however, our understanding of host factors that influence AAV transduction in different cell types is still evolving. In the present study, we perform a genome-scale CRISPR knockout screen to identify cellular host factors that restrict AAV infection in hepatocyte cultures. We discover that Crumbs 3, which determines cellular polarity, also influences the distribution of certain carbohydrate attachment factors on the cell surface. This in turn affects the ability of virions to bind and enter the cells. This study underscores the importance of cell polarity in AAV transduction and provides a potential molecular basis for the differential infectious mechanism(s) in cell culture versus organ systems.

Modulation of Sialic Acid Dependence Influences the Central Nervous System Transduction Profile of Adeno-associated Viruses.

Central nervous system (CNS) transduction by systemically administered recombinant adeno-associated viral (AAV) vectors requires crossing the blood-brain barrier (BBB). We recently mapped a structural footprint on the AAVrh.10 capsid, which, when grafted onto the AAV1 capsid (AAV1RX), enables viral transport across the BBB; however, the underlying mechanisms remain unknown. Here, we establish through structural modeling that this footprint overlaps in part the sialic acid (SIA) footprint on AAV1. We hypothesized that altered SIA-capsid interactions may influence the ability of AAV1RX to transduce the CNS. Using AAV1 variants with altered SIA footprints, we map functional attributes of these capsids to their relative SIA dependence. Specifically, capsids with ablated SIA binding can penetrate and transduce the CNS with low to moderate efficiency. In contrast, AAV1 shows strong SIA dependency and does not transduce the CNS after systemic administration and, instead, transduces the vasculature and the liver. The AAV1RX variant, which shows an intermediate SIA binding phenotype, effectively enters the brain parenchyma and transduces neurons at levels comparable to the level of AAVrh.10. In corollary, the reciprocal swap of the AAV1RX footprint onto AAVrh.10 (AAVRX1) attenuated CNS transduction relative to that of AAVrh.10. We conclude that the composition of residues within the capsid variable region 1 (VR1) of AAV1 and AAVrh.10 profoundly influences tropism, with altered SIA interactions playing a partial role in this phenotype. Further, we postulate a Goldilocks model, wherein optimal glycan interactions can influence the CNS transduction profile of AAV capsids.IMPORTANCE Understanding how viruses cross the blood-brain barrier can provide insight into new approaches to block infection by pathogens or the ability to exploit these pathways for designing new recombinant viral vectors for gene therapy. In this regard, modulation of virus-carbohydrate interactions by mutating the virion shell can influence the ability of recombinant viruses to cross the vascular barrier, enter the brain, and enable efficient gene transfer to neurons.