Supramolecular assembly of polycation/mRNA nanoparticles and in vivo monocyte programming.

Size-dependent phagocytosis is a well-characterized phenomenon in monocytes and macrophages. However, this size effect for preferential gene delivery to these important cell targets has not been fully exploited because commonly adopted stabilization methods for electrostatically complexed nucleic acid nanoparticles, such as PEGylation and charge repulsion, typically arrest the vehicle size below 200 nm. Here, we bridge the technical gap in scalable synthesis of larger submicron gene delivery vehicles by electrostatic self-assembly of charged nanoparticles, facilitated by a polymer structurally designed to modulate internanoparticle Coulombic and van der Waals forces. Specifically, our strategy permits controlled assembly of small poly(ß-amino ester)/messenger ribonucleic acid (mRNA) nanoparticles into particles with a size that is kinetically tunable between 200 and 1,000 nm with high colloidal stability in physiological media. We found that assembled particles with an average size of 400 nm safely and most efficiently transfect monocytes following intravenous administration and mediate their differentiation into macrophages in the periphery. When a CpG adjuvant is co-loaded into the particles with an antigen mRNA, the monocytes differentiate into inflammatory dendritic cells and prime adaptive anticancer immunity in the tumor-draining lymph node. This platform technology offers a unique ligand-independent, particle-size-mediated strategy for preferential mRNA delivery and enables therapeutic paradigms via monocyte programming.

CODA: quantitative 3D reconstruction of large tissues at cellular resolution.

A central challenge in biology is obtaining high-content, high-resolution information while analyzing tissue samples at volumes relevant to disease progression. We address this here with CODA, a method to reconstruct exceptionally large (up to multicentimeter cubed) tissues at subcellular resolution using serially sectioned hematoxylin and eosin-stained tissue sections. Here we demonstrate CODA's ability to reconstruct three-dimensional (3D) distinct microanatomical structures in pancreas, skin, lung and liver tissues. CODA allows creation of readily quantifiable tissue volumes amenable to biological research. As a testbed, we assess the microanatomy of the human pancreas during tumorigenesis within the branching pancreatic ductal system, labeling ten distinct structures to examine heterogeneity and structural transformation during neoplastic progression. We show that pancreatic precancerous lesions develop into distinct 3D morphological phenotypes and that pancreatic cancer tends to spread far from the bulk tumor along collagen fibers that are highly aligned to the 3D curves of ductal, lobular, vascular and neural structures. Thus, CODA establishes a means to transform broadly the structural study of human diseases through exploration of exhaustively labeled 3D microarchitecture.

Vascularized Denervated Muscle Targets for Headache Surgery-Presentation and Surgical Management.

Patients with substantial trauma to their occipital nerves and those with recurrent or persistent chronic headaches after occipital nerve decompression surgery require transection of their greater occipital and/or lesser occipital nerves to control debilitating pain. Current techniques, such as burying the transected nerve stump in nearby muscle, do not prevent neuroma formation, and more advanced techniques, such as targeted muscle reinnervation and regenerative peripheral nerve interface, have demonstrated only short-term anecdotal success in the context of headache surgery. Vascularized denervated muscle targets (VDMTs) are a novel technique to address the proximal nerve stump after nerve transection that has shown promise to improve chronic nerve pain and prevent neuroma formation. However, VDMTs have not been described in the context of headache surgery. Here authors describe the etiology, workup, and surgical management of 2 patients with recurrent occipital neuralgia who developed vexing neuromas after previous surgery and were successfully treated with VDMTs, remaining pain-free at 3-year follow-up.

Perforator Characteristics and Impact on Postoperative Outcomes in DIEP Flap Breast Reconstruction: A Systematic Review and Meta-Analysis.

BACKGROUND: High-quality evidence on perforator selection in deep inferior epigastric perforator (DIEP) flap harvesting is lacking, making preoperative planning and choice of perforators "surgeon-specific." This lack of consensus is a subject of continuous debate among microsurgeons. We aimed to systematically review perforator characteristics and their impact on DIEP flap breast reconstruction outcomes. METHODS: We conducted a systematic review and meta-analysis across six databases: ClinicalTrials.gov, Cochrane Library, Medline, Ovid Embase, PubMed, and Web of Science for all studies on DIEP flap breast reconstruction focused on perforator characteristics-caliber, number, and location. The primary goal was to analyze the impact of perforator characteristics on partial and/or total flap failure and fat necrosis. Data was analyzed using RevMan V5.3. RESULTS: Initial search gave us 2,768 articles of which 17 were included in our review. Pooled analysis did not show any statistically significant correlations between partial and/or total flap failure and perforator number, or perforator location. Sensitivity analysis accounting for heterogeneity across studies showed that, the risk for fat necrosis was significantly higher if single perforators (relative risk [RR] = 2.0, 95% confidence interval [CI] = 1.5-2.6, I 2 = 39%) and medial row perforators (RR = 2.7, 95% CI = 1.8-3.9, I 2 = 0%) were used. CONCLUSION: Our findings suggest that a single dominant perforator and medial row perforators may be associated with higher risk of fat necrosis after DIEP flap breast reconstruction. Adopting a standardized perforator selection algorithm may facilitate operative decision making, shorten the learning curve for novice surgeons, and optimize postoperative outcomes by minimizing the burden of major complications. This in turn would help improve patient satisfaction and quality of life.

Biostimulatory Micro-Fragmented Nanofiber-Hydrogel Composite Improves Mesenchymal Stem Cell Delivery and Soft Tissue Remodeling.

Functional microgels are preferred stem cell carriers due to the ease of delivery through minimally invasive injection and seamless integration with the surrounding host tissue. A biostimulatory nanofiber-hydrogel composite (NHC) has been previously developed through covalently crosslinking a hyaluronic acid hydrogel network with surface-functionalized poly (ε-caprolactone) nanofiber fragments. The NHC mimics the microarchitecture of native soft tissue matrix, showing enhanced cell infiltration, immunomodulation, and proangiogenic properties. Here, injectability of the pre-formed NHC is improved by mechanical fragmentation, making it into micro-fragmented NHC (mfNHC) in a granular gel form as a stem cell carrier to deliver mesenchymal stem cells (MSCs) for soft tissue remodeling. The mfNHC shows a similar storage modulus but a significantly reduced injection force, as compared with the corresponding bulk NHC. When injected subcutaneously in a rat model, mfNHC-MSC constructs initiate an elevated level of host macrophage infiltration, more pro-regenerative polarization, and subsequently, improved angiogenesis and adipogenesis response when compared to mfNHC alone. A similar trend of host cell infiltration and pro-angiogenic response is detected in a swine model with a larger volume injection. These results suggest a strong potential for use of the mfNHC as an injectable carrier for cell delivery and soft tissue remodeling.

Size-Controlled and Shelf-Stable DNA Particles for Production of Lentiviral Vectors.

Polyelectrolyte complex particles assembled from plasmid DNA (pDNA) and poly(ethylenimine) (PEI) have been widely used to produce lentiviral vectors (LVVs) for gene therapy. The current batch-mode preparation for pDNA/PEI particles presents limited reproducibility in large-scale LVV manufacturing processes, leading to challenges in tightly controlling particle stability, transfection outcomes, and LVV production yield. Here we identified the size of pDNA/PEI particles as a key determinant for a high transfection efficiency with an optimal size of 400-500 nm, due to a cellular-uptake-related mechanism. We developed a kinetics-based approach to assemble size-controlled and shelf-stable particles using preassembled nanoparticles as building blocks and demonstrated production scalability on a scale of at least 100 mL. The preservation of colloidal stability and transfection efficiency was benchmarked against particles generated using an industry standard protocol. This particle manufacturing method effectively streamlines the viral manufacturing process and improves the production quality and consistency.

Neuroma of The Supraorbital Nerve Following Forehead Flap Reconstruction - Presentation and Surgical Management.

ABSTRACT: Localized pain or headache from neuroma formation is a rare and challenging complication of forehead flap surgery. Here the authors present a patient who developed local pain and dysesthesia following iatrogenic injury to the left supraorbital nerve during forehead flap elevation. Following a diagnostic nerve block in clinic, surgical excision of the neuroma was performed through an upper blepharoplasty approach. The patient had immediate postoperative pain relief and remains pain free at fifteen-month follow-up. The authors describe etiology, workup, and surgical management of sensory nerve injury during forehead flap reconstruction.

Intensive Care Unit Monitoring After Pharyngeal Flap Surgery: Is It Necessary?

PURPOSE: To assess the incidence of perioperative complications and the utility of intensive care monitoring in patients undergoing posterior pharyngeal flap surgery for velopharyngeal dysfunction (VPD). MATERIALS AND METHODS: This study was a retrospective evaluation of patients who underwent posterior pharyngeal flap surgery for treatment of VPD and an assessment of the incidence of perioperative complications. Descriptive statistics were computed. RESULTS: Over an 18-year period, 145 patients underwent pharyngeal flap surgery for VPD; 133 (91.7%) had complete data and were included as subjects. Mean patient age was 9.4 ± 7.4 years; 50.4% were female. One hundred twenty-six patients (94.7%) had a history of cleft palate. Thirty-four patients (25.5%) had asthma or obstructive sleep apnea. Eighty-three patients (62.4%) were admitted to the intensive care unit (ICU) for postoperative monitoring. The average length of hospital stay was 1.9 ± 0.9 days (range, 1 to 5 days). There were no incidents of serious postoperative complications, including death, bleeding, flap dehiscence or loss, or airway compromise requiring reintubation. Two patients (1.5%) had perioperative complications related to respiratory issues, one of whom required readmission to the ICU (0.8%). There were no differences in complications between those who were routinely admitted to the ICU and those who went directly to the floor (P = 1.00). There was no association between respiratory comorbidities and complications (P = .06). CONCLUSION: The perioperative complication rate for posterior pharyngeal flap surgery is low (<2%). Routine ICU admission for monitoring is not necessary.

Pyoderma Gangrenosum After Breast Surgery: Diagnostic Pearls and Treatment Recommendations Based on a Systematic Literature Review.

BACKGROUND: Pyoderma gangrenosum (PG) is a rare cutaneous disorder that poses a diagnostic challenge in the postoperative period. A systematic literature review was performed to determine distinguishing characteristics of PG in the setting of breast surgery that can facilitate timely diagnosis and appropriate treatment. METHODS: PubMed, EMBASE, Scopus, and Web of Science databases were systematically searched for articles with cases of PG occurring after breast surgery. Forty-three relevant articles, including 49 case reports, were identified. RESULTS: PG manifested bilaterally in 30 of 34 cases (88%) in which bilateral surgery was performed. Abdominal wounds were present in 6 of 7 cases in which an abdominal donor site was used for breast reconstruction. Nipples were spared from wound involvement in 33 of 37 cases (89%) in which nipples were present after surgery. Presence of fever was noted in 27 cases (55%) and leukocytosis in 21 cases (43%). A total of 33 patients (67%) underwent wound debridement. Successful medical treatment most commonly involved steroids (41 cases, 84%) and cyclosporine (10 cases, 20%). CONCLUSIONS: Pertinent clinical features were identified that may aid in timely diagnosis and treatment of PG after breast surgery. Appearance of discrete wounds involving multiple surgical sites that surround but spare the nipples should raise suspicion for PG rather than infection or ischemia, even with concomitant fever and leukocytosis. Wound debridement should be minimized and skin grafting considered only after medical therapy is initiated. Cognizance of these features may enable prompt therapeutic intervention that minimizes morbidity and improves outcomes.

Facial paralysis in children.

Facial paralysis can have devastating physical and psychosocial consequences. These are particularly severe in children in whom loss of emotional expressiveness can impair social development and integration. The etiologies of facial paralysis, prospects for spontaneous recovery, and functions requiring restoration differ in children as compared with adults. Here we review contemporary management of facial paralysis with a focus on special considerations for pediatric patients.

Biosensors: An Upcoming Wave of Innovation.

SUMMARY: A biosensor uses a biological molecule to measure a chemical reaction. Wearable biosensors that attach to the body externally, including tooth enamel biosensors, contact lens biosensors, sweat biosensors, and skin tattoo biosensors, are in development. Nanoparticle-based biosensors are being developed to allow for the early detection of cancerous biomarkers. Applications relevant to plastic surgery include the development of biosensors that can detect metastatic breast cancer cells, bioimpedance spectroscopy, and intraoperative point-of-care diagnostics.

Artificial Intelligence: Singularity Approaches.

SUMMARY: Artificial intelligence (AI) has been a disruptive technology within health care, from the development of simple care algorithms to complex deep-learning models. AI has the potential to reduce the burden of administrative tasks, advance clinical decision-making, and improve patient outcomes. Unlocking the full potential of AI requires the analysis of vast quantities of clinical information. Although AI holds tremendous promise, widespread adoption within plastic surgery remains limited. Understanding the basics is essential for plastic surgeons to evaluate the potential uses of AI. This review provides an introduction of AI, including the history of AI, key concepts, applications of AI in plastic surgery, and future implications.

Commensal microbe regulation of skin cells in disease.

Human skin is the host to various commensal microbes that constitute a substantial microbial community. The reciprocal communication between these microbial inhabitants and host cells upholds both the morphological and functional attributes of the skin layers, contributing indispensably to microenvironmental and tissue homeostasis. Thus, disruption of the skin barrier or imbalances in the microbial communities can exert profound effects on the behavior of host cells. This influence, mediated by the microbes themselves or their metabolites, manifests in diverse outcomes. In this review, we examine existing knowledge to provide insight into the nuanced behavior exhibited by the microbiota on skin cells in health and disease states. These interactions provide insight into potential cellular targets for future microbiota-based therapies to prevent and treat skin disease.

Integrated transcriptomics of human blood vessels defines a spatially controlled niche for early mesenchymal progenitor cells.

Human blood vessel walls show concentric layers, with the outermost tunica adventitia harboring mesenchymal progenitor cells. These progenitor cells maintain vessel homeostasis and provide a robust cell source for cell-based therapies. However, human adventitial stem cell niche has not been studied in detail. Here, using spatial and single-cell transcriptomics, we characterized the phenotype, potential, and microanatomic distribution of human perivascular progenitors. Initially, spatial transcriptomics identified heterogeneity between perivascular layers of arteries and veins and delineated the tunica adventitia into inner and outer layers. From this spatial atlas, we inferred a hierarchy of mesenchymal progenitors dictated by a more primitive cell with a high surface expression of CD201 (PROCR). When isolated from humans and mice, CD201Low expression typified a mesodermal committed subset with higher osteogenesis and less proliferation than CD201High cells, with a downstream effect on canonical Wnt signaling through DACT2. CD201Low cells also displayed high translational potential for bone tissue generation.

qMAP enabled microanatomical mapping of human skin aging.

Aging is a major driver of diseases in humans. Identifying features associated with aging is essential for designing robust intervention strategies and discovering novel biomarkers of aging. Extensive studies at both the molecular and organ/whole-body physiological scales have helped determined features associated with aging. However, the lack of meso-scale studies, particularly at the tissue level, limits the ability to translate findings made at molecular scale to impaired tissue functions associated with aging. In this work, we established a tissue image analysis workflow - quantitative micro-anatomical phenotyping (qMAP) - that leverages deep learning and machine vision to fully label tissue and cellular compartments in tissue sections. The fully mapped tissue images address the challenges of finding an interpretable feature set to quantitatively profile age-related microanatomic changes. We optimized qMAP for skin tissues and applied it to a cohort of 99 donors aged 14 to 92. We extracted 914 microanatomic features and found that a broad spectrum of these features, represented by 10 cores processes, are strongly associated with aging. Our analysis shows that microanatomical features of the skin can predict aging with a mean absolute error (MAE) of 7.7 years, comparable to state-of-the-art epigenetic clocks. Our study demonstrates that tissue-level architectural changes are strongly associated with aging and represent a novel category of aging biomarkers that complement molecular markers. Our results highlight the complex and underexplored multi-scale relationship between molecular and tissue microanatomic scales.

Le Fort II fractures are associated with death: a comparison of simple and complex midface fractures.

PURPOSE: To investigate whether complex midface fractures have a greater association with death and intracranial injury than simple midface fractures. MATERIALS AND METHODS: A retrospective chart review was performed for patients with blunt-mechanism midface fractures who had presented to an urban trauma center from 1998 to 2010. The survival and intracranial injury status was evaluated for patients with simple and complex midface fractures, including Le Fort, naso-orbitoethmoid, and/or zygomaticomaxillary fractures. Intracranial injury included hemorrhage and brainstem injury. Patients with upper face fractures were excluded to minimize confounding. Adjusted relative risk estimates were obtained using multivariate regression analysis. RESULTS: Of 3,291 patients with midface fractures, 213 (6.3%) died and 693 (21.3%) had an intracranial injury. The cumulative mortality reached 11.6% in patients with complex midface fractures and 5.1% in those with simple midface fractures (P < .001). Patients with complex midface fractures were 57% more likely to die (relative risk = 1.57; P < .005). Specifically, Le Fort II fractures independently conferred a 94% increased risk of death (relative risk = 1.94; P < .01), but Le Fort I and III fractures were not significantly associated with death. Among patients presenting without neurologic impairment, those with Le Fort II and III fractures remained 2.88-fold (P < .01) and 2.54-fold (P < .001) more likely to have an underlying intracranial injury, respectively. CONCLUSIONS: Le Fort II fractures are associated with increased mortality. Furthermore, Le Fort II and III fractures are associated with serious intracranial injury, even in the absence of alterations in consciousness. These patients should be monitored with heightened vigilance and followed up closely during hospitalization, regardless of the presenting clinical findings.

Facial fractures of the upper craniofacial skeleton predict mortality and occult intracranial injury after blunt trauma: an analysis.

PURPOSE: The aim of this article was to assess how regional facial fracture patterns predict mortality and occult intracranial injury after blunt trauma. METHODS: Retrospective chart review was performed for blunt-mechanism craniofacial fracture patients who presented to an urban trauma center from 1998 to 2010. Fractures were confirmed by author review of computed tomographic imaging and then grouped into 1 of 5 patterns of regional involvement representing all possible permutations of facial-third injury. Mortality and the presence of occult intracranial injury, defined as those occurring in patients at low risk at presentation for head injury by Canadian CT Head Rule criteria, were evaluated. Relative risk estimates were obtained using multivariable regression. RESULTS: Of 4540 patients identified, 338 (7.4%) died, and 171 (8.1%) had intracranial injury despite normal Glasgow Coma Scale at presentation. Cumulative mortality reached 18.8% for isolated upper face fractures, compared with 6.9% and 4.0% for middle and lower face fractures (P < 0.001), respectively. Upper face fractures were independently associated with 4.06-, 3.46-, and 3.59-fold increased risk of death for the following fracture patterns: isolated upper, combined upper, panfacial, respectively (P < 0.001). Patients who were at low risk for head injury remained 4 to 6 times more likely to suffer an occult intracranial injury if they had involvement of the upper face. CONCLUSIONS: The association between facial fractures, intracranial injury, and death varies by regional involvement, with increasing insult in those with upper face fractures. Cognizance of the increased risk for intracranial injury in patients with upper face fractures may supplement existing triage tools and should increase suspicion for underlying or impending neuropathology, regardless of clinical picture at presentation.

Colonizing microbiota is associated with clinical outcomes in diabetic wound healing.

With the development of society and the improvement of life quality, more than 500 million people are affected by diabetes. More than 10 % of people with diabetes will suffer from diabetic wounds, and 80 % of diabetic wounds will reoccur, so the development of new diabetic wound treatments is of great importance. The development of skin microbe research technology has gradually drawn people's attention to the complex relationship between microbes and diabetic wounds. Many studies have shown that skin microbes are associated with the outcome of diabetic wounds and can even be used as one of the indicators of wound prognosis. Skin microbes have also been found to have the potential to treat diabetic wounds. The wound colonization of different bacteria can exert opposing therapeutic effects. It is necessary to fully understand the skin microbes in diabetic wounds, which can provide valuable guidance for clinical diabetic wound treatment.

Treatment of Persistent Post-traumatic Diplopia - An Algorithmic Approach to Patient Stratification and Operative Management.

Study Design: Retrospective chart review of revisional orbital surgery outcomes in patients with diplopia from prior operative treatment of orbital trauma. Objective: Our study seeks to review our experience with management of persistent post-traumatic diplopia in patients with previous orbital reconstruction and present a novel patient stratification algorithm predictive of improved outcomes. Methods: A retrospective chart review was performed on adult patients at Wilmer Eye Institute at Johns Hopkins Hospital and at the University of Maryland Medical Center who underwent revisional orbital surgery for correction of diplopia for the years 2005-2020. Restrictive strabismus was determined by Lancaster red-green testing coupled with computed tomography and/or forced duction. Globe position was assessed by computed tomography. Seventeen patients requiring operative intervention according to study criteria were identified. Results: Globe malposition affected fourteen patients and restrictive strabismus affected eleven patients. In this select group, improvement in diplopia occurred in 85.7% of cases with globe malposition and in 90.1% of cases with restrictive strabismus. One patient underwent additional strabismus surgery subsequent to orbital repair. Conclusions: Post-traumatic diplopia in patients with prior orbital reconstruction can be successfully managed in appropriate patients with a high degree of success. Indications for surgical management include (1) globe malposition and (2) restrictive strabismus. High resolution computer tomography and Lancaster red-green testing discriminate these from other causes that are unlikely to benefit from orbital surgery.