Cell-free plasma next-generation sequencing assists in the evaluation of secondary pneumonia in patients with COVID-19: a case series.

Secondary pneumonia occurs in 8-24% of patients with Coronavirus 2019 (COVID-19) infection and is associated with increased morbidity and mortality. Diagnosis of secondary pneumonia can be challenging. The purpose of this study was to evaluate the use of plasma microbial cell free DNA sequencing (mcfNGS) in the evaluation of secondary pneumonia after COVID-19. We performed a single-center case series of patients with COVID-19 who underwent mcfNGS to evaluate secondary pneumonia and reported the organisms identified, concordance with available tests, clinical utility, and outcomes. In 8/13 (61%) cases, mcfNGS detected 1-6 organisms, with clinically significant organisms identified in 4 cases, including Pneumocystis jirovecii, and Legionella spp. Management was changed in 85% (11/13) of patients based on results, including initiation of targeted therapy, de-escalation of empiric antimicrobials, and avoiding contingent escalation of antifungals. mcfNGS may be helpful to identify pathogens causing secondary pneumonia, including opportunistic pathogens in immunocompromised patients with COVID-19. However, providers need to carefully interpret this test within the clinical context.

Nanobodies as allosteric modulators of Parkinson's disease-associated LRRK2.

Mutations in the gene coding for leucine-rich repeat kinase 2 (LRRK2) are a leading cause of the inherited form of Parkinson's disease (PD), while LRRK2 overactivation is also associated with the more common idiopathic form of PD. LRRK2 is a large multidomain protein, including a GTPase as well as a Ser/Thr protein kinase domain. Common, disease-causing mutations increase LRRK2 kinase activity, presenting LRRK2 as an attractive target for drug discovery. Currently, drug development has mainly focused on ATP-competitive kinase inhibitors. Here, we report the identification and characterization of a variety of nanobodies that bind to different LRRK2 domains and inhibit or activate LRRK2 in cells and in in vitro. Importantly, nanobodies were identified that inhibit LRRK2 kinase activity while binding to a site that is topographically distinct from the active site and thus act through an allosteric inhibitory mechanism that does not involve binding to the ATP pocket or even to the kinase domain. Moreover, while certain nanobodies completely inhibit the LRRK2 kinase activity, we also identified nanobodies that specifically inhibit the phosphorylation of Rab protein substrates. Finally, in contrast to current type I kinase inhibitors, the studied kinase-inhibitory nanobodies did not induce LRRK2 microtubule association. These comprehensively characterized nanobodies represent versatile tools to study the LRRK2 function and mechanism and can pave the way toward novel diagnostic and therapeutic strategies for PD.

Keratinocyte-Macrophage Crosstalk by the Nrf2/Ccl2/EGF Signaling Axis Orchestrates Tissue Repair.

Unveiling the molecular mechanisms underlying tissue regeneration provides new opportunities to develop treatments for diabetic ulcers and other chronic skin lesions. Here, we show that Ccl2 secretion by epidermal keratinocytes is directly orchestrated by Nrf2, a prominent transcriptional regulator of tissue regeneration that is activated early after cutaneous injury. Through a unique feedback mechanism, we find that Ccl2 from epidermal keratinocytes not only drives chemotaxis of macrophages into the wound but also triggers macrophage expression of EGF, which in turn activates basal epidermal keratinocyte proliferation. Notably, we find dysfunctional activation of Nrf2 in epidermal keratinocytes of diabetic mice after wounding, which partly explains regenerative impairments associated with diabetes. These findings provide mechanistic insight into the critical relationship between keratinocyte and macrophage signaling during tissue repair, providing the basis for continued investigation of the therapeutic value of Nrf2.

Revisiting the Reverse Sural Artery Flap in Distal Lower Extremity Reconstruction: A Systematic Review and Risk Analysis.

BACKGROUND: The reverse sural artery flap (RSAF) is a popular option for patients with distal lower extremity defects who are not ideal candidates for free flap reconstruction. This is the first systematic review and pooled analysis of surgical characteristics, risk factors, and outcomes of the RSAF. METHODS: A systematic literature review was conducted. All studies reporting on patients undergoing RSAF reconstruction and their outcomes were included. Outcomes were pooled and analyzed using Fisher exact or χ test. RESULTS: Forty-three studies (479 patients, 481 flaps) were analyzed. The majority of patients were male (70.3%), and average ± SD age was 46.9 ± 16.7 years. Rates of smoking, diabetes mellitus (DM), and peripheral vascular disease (PVD) were 34.6%, 35.4%, and 12.3%, respectively. Defect etiologies were largely traumatic (60.4%). The most common defect location was the heel (40.8%). Flap modifications were reported in 123 flaps (25.6%). The most common modification was adipofascial extension (20.3%).Overall, the partial and total flap loss rates were 15.4% and 3.1%, respectively. Partial flap loss was significantly increased in smokers (28.9% vs 12.2% in nonsmokers, P = 0.0195). Technical modifications decreased the odds of partial necrosis by almost 3-fold compared with traditional RSAF reconstruction (7.2% vs 17.9%; odds ratio, 2.8 [1.4-5.8]; P = 0.0035). Patient age, DM, and PVD were not significantly associated with flap loss. CONCLUSIONS: The RSAF remains a safe salvage option for patients with DM or PVD but should be used with caution in smokers. Technical modifications to minimize pedicle compression significantly reduce rates of partial necrosis.

Subcutaneous-Only Gluteal Fat Grafting: A Prospective Study of the Long-Term Results with Ultrasound Analysis.

In recent years, gluteal fat augmentation has exhibited some of the most significant growth among all plastic surgery procedures. However, as the popularity of and media attention to gluteal fat augmentation continue to rise, reports of fatalities, largely attributed to fat embolism, have raised valid concerns. Many plastic surgeons inject fat in the intramuscular plane and claim better graft take in the muscles and the possibility of injecting more volume in the gluteal region. Because of the large caliber of vessels, subcutaneous fat augmentation has been a preference of many. However, the long-term outcome of fat injected into the subcutaneous layer has been questionable, and there is a lack of prospective quantitative studies of subcutaneous-only fat grafting. Therefore, the authors evaluated the long-term maintenance of gluteal adipose thickness when fat was injected only subcutaneously. Fifty consecutive female patients were evaluated in this prospective clinical study. All patients underwent gluteal fat augmentation in the subcutaneous plane only. Ultrasound analysis of the adipose tissue thickness of the gluteal region was performed preoperatively, immediately postoperatively, and at 12 months postoperatively. Immediate postoperative measurements revealed an average increase in gluteal subcutaneous layer thickness of 56.51 percent (range, 39.5 to 108.6 percent) (p < 0.0001). At 12 months postoperatively, the gluteal adipose tissue thickness decreased by an average of 18.16 percent (range, 6.8 to 24.8 percent) (p < 0.0001). Subcutaneous-only gluteal fat augmentation is shown to be as effective as previous studies reporting intramuscular fat injection with regard to long-term fat retention in the buttocks. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, IV.

Diabetes is not associated with increased rates of free flap failure: Analysis of outcomes in 6030 patients from the ACS-NSQIP database.

BACKGROUND: Diabetes affects a significant proportion of the population in the United States. Microsurgical procedures are common in this patient population, and despite many conflicting reports in the literature, there are no large studies evaluating the direct association between diabetes and outcomes, specifically failure, following free flap reconstruction. In this study, we sought to determine the impact of diabetes on postoperative outcomes following free flap reconstruction using a national multi-institutional database. METHODS: We reviewed the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to identify patients undergoing free flap reconstruction from 2010 to 2015. Preoperative variables and outcomes were compared between diabetic and nondiabetic patients. Univariate and multivariate analyses were performed to control for confounders. RESULTS: We identified 6030 eligible patients. No significant difference in flap failure rates was observed. However, diabetic patients presented significantly higher rates of wound complications, including deep incisional surgical site infection (SSI) (OR = 1.35; P = .01) and wound dehiscence (OR = 1.17; P = .03). Diabetic patients also presented a significantly longer hospital length of stay (LOS) (ß = .62; P < .001). CONCLUSIONS: Our study evaluated the largest national cohort of free flap procedures. These results suggest that diabetes is not associated with increased rates of flap failure. However, diabetic patients are at significantly higher risk of postoperative deep incisional SSI, wound dehiscence, and longer LOS. Our findings provide the most concrete evidence to date in support of free flap reconstruction in diabetic patients, but highlight the need for heightened clinical vigilance and wound care for optimal outcomes.

A Prospective, Randomized, Blinded Trial Comparing Digital Simulation to Textbook for Cleft Surgery Education.

BACKGROUND: Simulation is progressively being integrated into surgical training; however, its utility in plastic surgery has not been well described. The authors present a prospective, randomized, blinded trial comparing digital simulation to a surgical textbook for conceptualization of cleft lip repair. METHODS: Thirty-five medical students were randomized to learning cleft repair using a simulator or a textbook. Participants outlined markings for a standard cleft lip repair before (preintervention) and after (postintervention) 20 minutes of studying their respective resource. Two expert reviewers blindly graded markings according to a 10-point scale, on two separate occasions. Intrarater and interrater reliability were calculated using intraclass correlation coefficients. Paired and independent t tests were performed to compare scoring between study groups. A validated student satisfaction survey was administered to assess the two resources separately. RESULTS: Intrarater grading reliability was excellent for both raters for preintervention and postintervention grading (rater 1, intraclass correlation coefficient = 0.94 and 0.95, respectively; rater 2, intraclass correlation coefficient = 0.60 and 0.92, respectively; p < 0.001). Mean preintervention performances for both groups were comparable (0.82 ± 1.17 versus 0.64 ± 0.95; p = 0.31). Significant improvement from preintervention to postintervention performance was observed in the textbook (0.82 ± 1.17 versus 3.50 ± 1.62; p < 0.001) and simulator (0.64 ± 0.95 versus 6.44 ± 2.03; p < 0.001) groups. However, the simulator group demonstrated a significantly greater improvement (5.81 ± 2.01 versus 2.68 ± 1.49; p < 0.001). Participants reported the simulator to be more effective (p < 0.001) and a clearer tool (p < 0.001), that allowed better learning (p < 0.001) than textbooks. All participants would recommend the simulator to others. CONCLUSION: The authors present evidence from a prospective, randomized, blinded trial supporting online digital simulation as a superior educational resource for novice learners, compared with traditional textbooks.

Current Management of Self-Inflicted Wounds in Surgery: A Critical Review.

OBJECTIVE: Despite the presence of self-inflicted wounds (SIWs) across all of medicine, our current understanding of SIWs in surgery is limited. Here, we detail the pertinent aspects of the history, diagnosis, decision making, and management of SIWs as they relate to the field of surgery. In addition, we present the first comprehensive review of SIWs across the surgical literature. SUMMARY BACKGROUND DATA: Self-inflicted wounds have been recognized for much of recorded human history and span a wide spectrum of patient behaviors, motivations, and underlying psychiatric illnesses. METHODS: We performed a comprehensive literature review of SIWs in the surgical literature. In total, 189 articles were identified. RESULTS: The most common site of primary SIW was the upper extremity (36.2%), and the most common presenting injuries were lacerations (22.7%). Forty-two percent of patients had received prior surgical procedures for their SIWs, and the average length of time preceding treatment or diagnosis of an injury as an SIW was 2.29 years. Self-inflicted wounds resulting from foreign body insertions were most common (25.9%). Psychiatric factors accounted for most SIW production (35%), of which factitious disorder was the most common (12.7%). Other motivations for SIW production included autoeroticism (8.6%), substance related (6.6%), organic brain disease (5.0%), and self-therapy/surgery by patients (1.7%). Surgical management was ultimately required for nearly 75% of SIWs and was successful in most cases. CONCLUSIONS: Self-inflicted wounds are frequently encountered in all surgical specialties and encompass many anatomic locations, presentations, and patient-motivating factors. Surgical intervention is common, and successful outcomes are often achieved.

Abdominal Panniculectomy: Determining the Impact of Diabetes on Complications and Risk Factors for Adverse Events.

BACKGROUND: The prevalence of obesity along with bariatric surgery and massive weight loss requiring panniculectomy is increasing in the United States. The effect of diabetes mellitus on outcomes following panniculectomy remains poorly defined despite its prevalence. This study aims to evaluate the impact of diabetes mellitus on complications following panniculectomy and determine risk factors for adverse events. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was used to identify patients undergoing panniculectomy between 2010 and 2015. Patients were stratified based on diabetes status. RESULTS: Review of the database identified 7035 eligible patients who underwent panniculectomy, of which 770 (10.9 percent) were diabetic. Multivariate regression showed that diabetes mellitus was a significant risk factor for wound dehiscence (OR, 1.92; 95 percent CI, 1.41 to 3.15; p = 0.02). Obesity was a significant risk factor for superficial (OR, 2.78; 95 percent CI, 1.53 to 3.69; p < 0.001) and deep (OR, 1.52; 95 percent CI, 1.38 to 3.97; p = 0.01) incisional surgical-site infection. Smokers were also at an increased risk for superficial (OR, 1.42; 95 percent CI, 1.19 to 1.75; p = 0.03) and deep (OR, 1.63; 95 percent CI, 1.31 to 2.22; p = 0.02) incisional surgical-site infection. CONCLUSIONS: Diabetes mellitus is an independent risk factor for wound dehiscence following panniculectomy. Obesity and smoking were significant risk factors for superficial and deep incisional surgical-site infection. These results underscore the importance of preoperative risk factor evaluation in patients undergoing panniculectomy for safe outcomes. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

Assessing the Value of a Multimedia-Based Aesthetic Curriculum in Plastic Surgery Residency: A Single-Center Pilot Study.

BACKGROUND: Although global demand for cosmetic surgery continues to rise, plastic surgery residents feel that current models of aesthetic training are inadequate in preparing them for future practice. Digital learning resources offer promising educational possibilities, yet there are no formal studies investigating the integration of these technologies into the aesthetic curriculum. OBJECTIVES: Here, we review the current state of aesthetic training for plastic surgery residents and present a pilot study investigating the value of a dedicated multimedia-based aesthetic curriculum at a single, large academic program. METHODS: Twenty plastic surgery residents participated in an 8-week curriculum consisting of weekly multimedia-based modules covering a specific aesthetic topic. Participants completed pre- and post-intervention surveys at 0 and 10 weeks, respectively. Surveys evaluated resident perspectives of the current state of aesthetic training, confidence in performing surgical and non-surgical aesthetic procedures, perceived efficacy of multimedia interventions for learning, and preferences for inclusion of such approaches in future curricula. RESULTS: 16.7% of participants planned on entering an aesthetic fellowship following residency. The mean number of months of dedicated cosmetic surgery rotations was 1.65 months. Resident confidence level in performing a particular aesthetic procedure significantly increased in 6/14 modules. More than 90% of residents were interested in incorporating the modules into residency. CONCLUSIONS: Technology-based aesthetic training is critical for producing the finest future practitioners and leaders of this specialty. Here, we show that plastic surgery residents can benefit from a multimedia-based aesthetic curriculum, even if they do not plan on pursuing a career devoted to cosmetic surgery.

Use of Tranexamic Acid to Reduce Blood Loss in Liposuction.

BACKGROUND: The use of tranexamic acid for blood loss prevention has gained popularity in many specialties, including plastic surgery. However, its use in liposuction has not been studied. The authors present a prospective, double-blind, nonrandomized study evaluating the efficacy of tranexamic acid in reducing perioperative blood loss during liposuction. METHODS: Twenty women undergoing liposuction were divided into two cohorts. Group 1 (n = 10) received a standard dose of 10 mg/kg of tranexamic acid intravenously in the preoperative and postoperative periods, whereas group 2 (n = 10) received a placebo. Patient hematocrit levels were evaluated preoperatively and postoperatively. Blood volume in the infranatant of the lipoaspirate was also measured; t tests were used for statistical analysis. RESULTS: Age, body mass index, and volume of lipoaspirate were comparable between the two cohorts. The volume of blood loss for every liter of lipoaspirate was 56.2 percent less in the tranexamic group compared with the control group (p < 0.001). Hematocrit levels at day 7 postoperatively were 48 percent less in group 1 compared with group 2 (p = 0.001). Furthermore, a 1 percent drop in the hematocrit level was found after liposuction of 812 ± 432 ml in group 1 and 379 ± 204 ml in group 2. Thus, the use of tranexamic acid could allow for aspiration of 114 percent more fat, with comparable variation in hematocrit levels. CONCLUSIONS: Tranexamic acid has been shown to be effective for minimizing perioperative blood loss in liposuction. Further large randomized controlled studies are required to corroborate this effect. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Achievements and Challenges in Facial Transplantation.

: The first facial transplantation in 2005 ushered in a new era in reconstructive surgery, offering new possibilities for the repair of severe disfigurements previously limited by conventional techniques. Advances in allograft design, computerized preoperative planning, surgical technique, and postoperative revisions have helped push the boundaries in this new frontier of vascularized composite allotransplantation. Over the past 12 years, 40 of these procedures have been performed across the world, offering the field the opportunity to reflect on current outcomes. Successes achieved in the brief history of facial transplantation have resulted in a new set of obstacles the field must now overcome. In this review, we aim to highlight the achievements, major challenges, and future directions of this rapidly evolving field.

Microenvironmental cues enhance mesenchymal stem cell-mediated immunomodulation and regulatory T-cell expansion.

Mesenchymal stem cells (MSCs) are known to both have powerful immunosuppressive properties and promote allograft tolerance. Determining the environmental oxygen tension and inflammatory conditions under which MSCs are optimally primed for this immunosuppressive function is essential to their utilization in promoting graft tolerance. Of particular interest is the mechanisms governing the interaction between MSCs and regulatory T cells (Tregs), which is relatively unknown. We performed our experiments utilizing rat bone marrow derived MSCs. We observed that priming MSCs in hypoxia promotes maintenance of stem-like characteristics, with greater expression of typical MSC cell-surface markers, increased proliferation, and maintenance of differentiation potential. Addition of autologous MSCs to CD4+/allogeneic endothelial cell (EC) co-culture increases regulatory T cell (Treg) proliferation, which is further enhanced when MSCs are primed in hypoxia. Furthermore, MSC-mediated Treg expansion does not require direct cell-cell contact. The expression of indolamine 2,3-dioxygenase, a mediator of MSC immunomodulation, increases when MSCs are primed in hypoxia, and inhibition of IDO significantly decreases the expansion of Tregs. Priming with inflammatory cytokines IFNγ and TNFα increases also expression of markers associated with MSC immunomodulatory function, but decreases MSC proliferation. The expression of IDO also increases when MSCs are primed with inflammatory cytokines. However, there is no increase in Treg expansion when MSCs are primed with IFNγ, suggesting an alternate mechanism for inflammatory-stimulated MSC immunomodulation. Overall, these results suggest that MSCs primed in hypoxia or inflammatory conditions are optimally primed for immunosuppressive function. These results provide a clearer picture of how to enhance MSC immunomodulation for clinical use.

Targeted Nrf2 activation therapy with RTA 408 enhances regenerative capacity of diabetic wounds.

AIMS: Though unmitigated oxidative stress in diabetic chronic non-healing wounds poses a major therapeutic challenge, currently, there are no effective pharmacological agents. We targeted the cytoprotective Nrf2/Keap1 pathway, which is dysfunctional in diabetic skin and the regenerative environment in the diabetic wound. We assessed the efficacy of a potent Nrf2-activator, RTA 408, a semi-synthetic oleanane triterpenoid, on accelerating diabetic wound healing. METHODS: Using Leprdb/dbmice, we made 10 mm-diameter excisional humanized wounds in dorsal skin. We administered RTA 408 formulations daily, and used ANOVA for comparison of time to closure, in vivo real-time ROS, histology, molecular changes. RESULTS: We found that RTA 408, specifically a 0.1% formulation, significantly reduced wound healing time and increased wound closure rate. While either systemic or topical administration of RTA 408 is effective, wound closure time with the latter was far superior. RTA 408-treated diabetic wounds upregulated Nrf2 and downstream antioxidant genes, and exhibited well-vascularized granulation tissue that aided in re-epithelialization. Reintroduction of redox mechanisms via RTA 408-induced Nrf2 resulted in reduction of the oxidative status of wounds, to coordinate successful wound closure. CONCLUSIONS: This preclinical study shows that promoting Nrf2-mediated antioxidant activity in the localized regenerative milieu of a diabetic wound markedly improves the molecular and cellular composition of diabetic wound beds. RTA 408 treats and corrects the irregularity in redox balance mechanisms involving Nrf2, in an avenue not explored previously for treatment of diabetic wounds and tissue regeneration. Our study supports development of RTA 408 as a therapeutic modality for chronic diabetic wounds.

Ex vivo allotransplantation engineering: Delivery of mesenchymal stem cells prolongs rejection-free allograft survival.

Current pharmacologic regimens in transplantation prevent allograft rejection through systemic recipient immunosuppression but are associated with severe morbidity and mortality. The ultimate goal of transplantation is the prevention of allograft rejection while maintaining recipient immunocompetence. We hypothesized that allografts could be engineered ex vivo (after allotransplant procurement but before transplantation) by using mesenchymal stem cell-based therapy to generate localized immunomodulation without affecting systemic recipient immunocompetence. To this end, we evaluated the therapeutic efficacy of bone marrow-derived mesenchymal stem cells in vitro and activated them toward an immunomodulatory fate by priming in inflammatory or hypoxic microenvironments. Using an established rat hindlimb model for allotransplantation, we were able to significantly prolong rejection-free allograft survival with a single perioperative ex vivo infusion of bone marrow-derived mesenchymal stem cells through the allograft vasculature, in the absence of long-term pharmacologic immunosuppression. Critically, transplanted rats rejected a second, nonengineered skin graft from the same donor species to the contralateral limb at a later date, demonstrating that recipient systemic immunocompetence remained intact. This study represents a novel approach in transplant immunology and highlights the significant therapeutic opportunity of the ex vivo period in transplant engineering.

The Nrf2/Keap1/ARE Pathway and Oxidative Stress as a Therapeutic Target in Type II Diabetes Mellitus.

Despite improvements in awareness and treatment of type II diabetes mellitus (TIIDM), this disease remains a major source of morbidity and mortality worldwide, and prevalence continues to rise. Oxidative damage caused by free radicals has long been known to contribute to the pathogenesis and progression of TIIDM and its complications. Only recently, however, has the role of the Nrf2/Keap1/ARE master antioxidant pathway in diabetic dysfunction begun to be elucidated. There is accumulating evidence that this pathway is implicated in diabetic damage to the pancreas, heart, and skin, among other cell types and tissues. Animal studies and clinical trials have shown promising results suggesting that activation of this pathway can delay or reverse some of these impairments in TIIDM. In this review, we outline the role of oxidative damage and the Nrf2/Keap1/ARE pathway in TIIDM, focusing on current and future efforts to utilize this relationship as a therapeutic target for prevention, prognosis, and treatment of TIID.

How many people work in your operating room? An assessment of factors associated with instrument recounts within plastic surgery.

BACKGROUND: Intraoperative instrument recounts are performed to avoid retained foreign surgical items. These additional counts, however, beget risks of their own, including prolonged operative times, exposure to radiation, and increased cost. Our study aimed to identify factors that increase the likelihood of instrument recounts during plastic surgery procedures, and use our findings to guide potential solutions for preventing unnecessary recounts across all surgical fields. STUDY DESIGN: This is a retrospective review of all plastic surgical cases in the main operating setting at New York University Langone Medical Center (NYULMC) between March 2014 and February 2015. RESULTS: Of 1285 plastic surgery cases, 35 (2.7%) reported a missing instrument necessitating a recount. Of all subspecialties within plastic surgery, only microsurgery conferred an increased risk of a recount event. We identified multiple factors that increased the odds of a recount event, including increased operative time, number of surgical sites, and intraoperative instrument handoffs. CONCLUSION: Instrument recounts, although designed to prevent inadvertently retained surgical items, present inherent risks of their own. In a large retrospective review of plastic surgery cases at our medical center, we identified many factors that increased the likelihood of an instrument recount. On the basis of our findings and prior literature, we recommend limiting the number of staff handling instrument, the number of handoffs, and a heightened awareness by surgeons and perioperative staff of specific procedures and factors that increase the risk of a miscount event.

Novel lipoproteoplex delivers Keap1 siRNA based gene therapy to accelerate diabetic wound healing.

Therapeutics utilizing siRNA are currently limited by the availability of safe and effective delivery systems. Cutaneous diseases, specifically ones with significant genetic components are ideal candidates for topical siRNA based therapy but the anatomical structure of skin presents a considerable hurdle. Here, we optimized a novel liposome and protein hybrid nanoparticle delivery system for the topical treatment of diabetic wounds with severe oxidative stress. We utilized a cationic lipid nanoparticle (CLN) composed of 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and the edge activator sodium cholate (NaChol), in a 6:1 ratio of DOTAP:NaChol (DNC). Addition of a cationic engineered supercharged coiled-coil protein (CSP) in a 10:1:1 ratio of DNC:CSP:siRNA produced a stable lipoproteoplex (LPP) nanoparticle, with optimal siRNA complexation, minimal cytotoxicity, and increased transfection efficacy. In a humanized murine diabetic wound healing model, our optimized LPP formulation successfully delivered siRNA targeted against Keap1, key repressor of Nrf2 which is a central regulator of redox mechanisms. Application of LPP complexing siKeap1 restored Nrf2 antioxidant function, accelerated diabetic tissue regeneration, and augmented reduction-oxidation homeostasis in the wound environment. Our topical LPP delivery system can readily be translated into clinical use for the treatment of diabetic wounds and can be extended to other cutaneous diseases with genetic components.

Cross-Reactive and Potent Neutralizing Antibody Responses in Human Survivors of Natural Ebolavirus Infection.

Recent studies have suggested that antibody-mediated protection against the Ebolaviruses may be achievable, but little is known about whether or not antibodies can confer cross-reactive protection against viruses belonging to diverse Ebolavirus species, such as Ebola virus (EBOV), Sudan virus (SUDV), and Bundibugyo virus (BDBV). We isolated a large panel of human monoclonal antibodies (mAbs) against BDBV glycoprotein (GP) using peripheral blood B cells from survivors of the 2007 BDBV outbreak in Uganda. We determined that a large proportion of mAbs with potent neutralizing activity against BDBV bind to the glycan cap and recognize diverse epitopes within this major antigenic site. We identified several glycan cap-specific mAbs that neutralized multiple ebolaviruses, including SUDV, and a cross-reactive mAb that completely protected guinea pigs from the lethal challenge with heterologous EBOV. Our results provide a roadmap to develop a single antibody-based treatment effective against multiple Ebolavirus infections.