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BACKGROUND: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) represent severe manifestations of a potentially life-threatening spectrum defined by a desquamating rash of the skin and mucous membranes. This study was prompted by the observed increase in the off-label use of lamotrigine as a causal agent in SJS/TEN in our regional burn center. METHODS: A retrospective cohort of 48 patients presenting to the Connecticut Burn Center from 2015-2022 with suspicion for SJS/TEN were reviewed for age, sex, causative drug, presenting symptoms, hospital course, biopsy confirmation, length of stay, comorbidities, and 30-day mortality. Descriptive statistical analysis was conducted to identify trends in causative agent, clinical presentation, and mortality. RESULTS: Thirty patients in our cohort received a final diagnosis of SJS/TEN. While antibiotics remain the most frequent cause of SJS/TEN across the study period (33.3 %, n = 10), the incidence of cases attributable to lamotrigine increased from 1 case between 2015 and 2018 (6.7 %) to 6 cases between 2019 and 2022 (40 %). In 2020 alone, 50 % of all cases were attributable to lamotrigine (n = 4). Of the patients where lamotrigine was implicated, 71.4 % (n = 5) were prescribed lamotrigine for off-label use in the treatment of non-bipolar mood disorders. The average lamotrigine-associated SJS/TEN patient was younger (p < 0.001), had fewer comorbidities, and was more likely to be female than the general SJS/TEN population. CONCLUSION: Off-label use of lamotrigine is emerging as a major driver of SJS/TEN with notable changes in patient demographics. Further research is necessary to understand how changing trends in the patient population will impact clinical course and optimal management.
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Chronic, non-healing wounds represent a significant challenge for healthcare systems worldwide, often requiring significant human and financial resources. Chronic wounds arise from the complex interplay of underlying comorbidities, such as diabetes or vascular diseases, lifestyle factors, and genetic risk profiles which may predispose extremities to local ischemia. Injuries are further exacerbated by bacterial colonization and the formation of biofilms. Infection, consequently, perpetuates a chronic inflammatory microenvironment, preventing the progression and completion of normal wound healing. The current standard of care (SOC) for chronic wounds involves surgical debridement along with localized wound irrigation, which requires inpatient care under general anesthesia. This could be followed by, if necessary, defect coverage via a reconstructive ladder utilizing wound debridement along with skin graft, local, or free flap techniques once the wound conditions are stabilized and adequate blood supply is restored. To promote physiological wound healing, a variety of approaches have been subjected to translational research. Beyond conventional wound healing drugs and devices that currently supplement treatments, cellular and immunotherapies have emerged as promising therapeutics that can behave as tailored therapies with cell- or molecule-specific wound healing properties. However, in contrast to the clinical omnipresence of chronic wound healing disorders, there remains a shortage of studies condensing the current body of evidence on cellular therapies and immunotherapies for chronic wounds. This review provides a comprehensive exploration of current therapies, experimental approaches, and translational studies, offering insights into their efficacy and limitations. Ultimately, we hope this line of research may serve as an evidence-based foundation to guide further experimental and translational approaches and optimize patient care long-term.
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Diabetes Mellitus , Cicatrização , Humanos , Cicatrização/fisiologia , Desbridamento/métodos , Pele , ImunoterapiaRESUMO
BACKGROUND: Smoking cessation therapy, including nicotine replacement therapy (NRT), is used perioperatively to assist patients to reduce their tobacco smoke intake and consequently decrease their risk of smoking-associated complications. There are, however, theoretical concerns that nicotine-induced peripheral vasoconstriction could impair wound healing. This study investigated the effect of NRT on postoperative outcomes in patients undergoing breast surgery. METHODS: A retrospective chart review of patients undergoing breast surgery within the Yale New Haven Health System from the years 2014 to 2020 was performed. Documented smoking status within 6 months before surgery, use or prescription of NRT, type of surgery, and surgical complications of infection, wound dehiscence, tissue necrosis, hematoma, seroma, fat necrosis, and return to operating room within 30 days were recorded. Demographic and complication data were compared between patients with NRT usage and those without using t-tests and chi-square analyses. Multivariable logistic regression models were created to predict the effect of NRT usage on the occurrence of any complication. RESULTS: A total of 613 breast procedures met inclusion criteria, of which 105 (17.2%) had documented NRT use. The NRT cohort and the non-NRT cohort were well balanced with respect to demographics and procedural variables. Upon multivariable modeling for risk of any surgical complication, NRT was not a significant predictor (odds ratio [OR]: 1.199, p = 0.607 and OR: 0.974, p = 0.912, respectively), whereas procedure type, increased body mass index, and increased age were. CONCLUSION: NRT use was not associated with an increased risk of postoperative complications compared with not using NRT as part of smoking cessation therapy prior to operation.
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Neoplasias da Mama , Abandono do Hábito de Fumar , Humanos , Feminino , Abandono do Hábito de Fumar/métodos , Agonistas Nicotínicos , Terapia de Substituição da Nicotina , Estudos Retrospectivos , Dispositivos para o Abandono do Uso de Tabaco , Prevenção do Hábito de Fumar , Complicações Pós-OperatóriasRESUMO
Apoptosis and clearance of apoptotic cells via efferocytosis are evolutionarily conserved processes that drive tissue repair. However, the mechanisms by which recognition and clearance of apoptotic cells regulate repair are not fully understood. Here, we use single-cell RNA sequencing to provide a map of the cellular dynamics during early inflammation in mouse skin wounds. We find that apoptotic pathways and efferocytosis receptors are elevated in fibroblasts and immune cells, including resident Lyve1+ macrophages, during inflammation. Interestingly, human diabetic foot wounds upregulate mRNAs for efferocytosis pathway genes and display altered efferocytosis signaling via the receptor Axl and its ligand Gas6. During early inflammation in mouse wounds, we detect upregulation of Axl in dendritic cells and fibroblasts via TLR3-independent mechanisms. Inhibition studies in vivo in mice reveal that Axl signaling is required for wound repair but is dispensable for efferocytosis. By contrast, inhibition of another efferocytosis receptor, Timd4, in mouse wounds decreases efferocytosis and abrogates wound repair. These data highlight the distinct mechanisms by which apoptotic cell detection coordinates tissue repair and provides potential therapeutic targets for chronic wounds in diabetic patients.
Our skin is constantly exposed to potential damage from the outside world, and it is vital that any injuries are repaired quickly and effectively. Diabetes and many other health conditions can hamper wound healing, resulting in chronic wounds that are both painful and at risk of becoming infected, which can lead to serious illness and death of patients. After an injury to the skin, the wound becomes inflamed as immune cells rush to the site of injury to fight off infection and clear the wound of dead cells and debris. Some of these dead cells will have died by a highly controlled process known as apoptosis. These so-called apoptotic cells display signals on their surface that nearby healthy cells recognize. This triggers the healthy cells to eat the apoptotic cells to remove them from the wound. Previous studies have linked changes in cell death and the removal of dead cells to chronic wounds in patients with diabetes, but it remains unclear how removing dead cells from the wound affects healing. Justynski et al. used a genetic technique called single-cell RNA sequencing to study the patterns of gene activity in mouse skin cells shortly after a wound. The experiments found that, as the area around the wound started to become inflamed, the wounded cells produced signals of apoptosis that in turn triggered nearby healthy cells to remove them. Other signals relating to the removal of dead cells were also widespread in the mouse wounds and treating the wounds with drugs that inhibit these signals resulted in multiple defects in the healing process. Further experiments used the same approach to study samples of tissue taken from foot wounds in human patients with or without diabetes. This revealed that several genes involved in the removal of dead cells were more highly expressed in the wounds of diabetic patients than in the wounds of other individuals. These findings indicate that for wounds to heal properly it is crucial for the body to detect and clear apoptotic cells from the wound site. Further studies building on this work may help to explain why some diabetic patients suffer from chronic wounds and help to develop more effective treatments for them.
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Apoptose , Eferocitose , Humanos , Animais , Camundongos , Apoptose/genética , Fibroblastos , Inflamação , Inibição PsicológicaRESUMO
Introduction: hiPSC-VSMCs have been suggested as therapeutic agents for wound healing and revascularization through the secretion of proangiogenic factors. However, methods of increasing cell paracrine secretion and survivability have thus far yielded inconsistent results. This study investigates the effect of pre-conditioning of hiPSC-VSMCs with TNF-α and their integration into 3D collagen scaffolds on cellular viability and secretome. Methods: hiPSC-VSMCs were dual-plated in a 2D environment. TNF-α was introduced to one plate. Following incubation, cells from each plate were divided and added to type-I collagen scaffolds. TNF-α was introduced to two sets of scaffolds, one from each 2D plate. Following incubation, scaffolds were harvested for their media, tested for cell survivability, cytotoxicity, and imaged. Intra-media VEGF and bFGF levels were evaluated using ELISA testing. Results: hiPSC-VSMCs exposed to TNF-α during collagen scaffold proliferation and preconditioning showed an increase in cell viability and less cytotoxicity compared to non-exposed cells and solely-preconditioned cells. Significant increases in bFGF expression were found in pre-conditioned cell groups with further increases found in cells subsequently exposed during intra-scaffold conditioning. A significant increase in VEGF expression was found in cell groups exposed during both pre-conditioning and intra-scaffold conditioning. Fibroblasts treated with any conditioned media demonstrated increased migration potential. Conclusions: Conditioning hiPSC-VSMCs embedded in scaffolds with TNF-α improves cellular viability and increases the secretion of paracrine factors necessary for wound healing mechanisms such as migration. Supplementary Information: The online version contains supplementary material available at 10.1007/s12195-023-00764-0.
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BACKGROUND: Sooner-than-expected progression to statewide lockdown at the height of the coronavirus disease 2019 pandemic left minimal time for medical specialty boards, including The American Board of Plastic Surgery, to issue guidance for their respective programs. As a result, programs were tasked with developing creative alternatives to their standard resident curricula and department schedules. OBJECTIVE: To capture attending and resident experience of the coronavirus disease 2019 lockdown in narrative form and to understand what specific changes enacted to maintain adequate education should be considered for continuation after the pandemic's conclusion. METHODS: Qualitative, semistructured interviews of residents, fellows, and faculty of the Section of Plastic and Reconstructive Surgery during 2019 to 2020 academic year were conducted on the following topics: (1) general reflection on lockdown, (2) resident maintenance of daily logs, (3) multi-institutional collaborative lectures, (4) modified didactic curriculum, (5) virtual 3-dimensional craniofacial planning sessions, (6) maintenance of department camaraderie, and (7) effect on preparation to become a surgeon. RESULTS: Twenty interviews (response rate 77%) were conducted between October 2020 and February 2021. Of residents, 100% felt observing the craniofacial planning sessions was beneficial, with many explicitly noting it provided a unique perspective into the surgeon's thought process behind planned manipulations, to which they usually are not privy. Of residents, 100% felt confident at the time of the interview that the lockdown would have no lasting effects on their preparation to become a surgeon. CONCLUSIONS: Rapid changes enacted at Yale enabled resident training to advance, and documentation of the success of these changes can inform future curriculum design.
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COVID-19 , Cirurgia Geral , Internato e Residência , Cirurgia Plástica , Humanos , Estados Unidos , COVID-19/epidemiologia , Cirurgia Plástica/educação , Controle de Doenças Transmissíveis , Currículo , Pesquisa Qualitativa , Cirurgia Geral/educaçãoRESUMO
Wound repair requires the coordination of multiple cell types including immune cells and tissue resident cells to coordinate healing and return of tissue function. Diabetic foot ulceration is a type of chronic wound that impacts over 4 million patients in the US and over 7 million worldwide (Edmonds et al., 2021). Yet, the cellular and molecular mechanisms that go awry in these wounds are not fully understood. Here, by profiling chronic foot ulcers from non-diabetic (NDFUs) and diabetic (DFUs) patients using single-cell RNA sequencing, we find that DFUs display transcription changes that implicate reduced keratinocyte differentiation, altered fibroblast function and lineages, and defects in macrophage metabolism, inflammation, and ECM production compared to NDFUs. Furthermore, analysis of cellular interactions reveals major alterations in several signaling pathways that are altered in DFUs. These data provide a view of the mechanisms by which diabetes alters healing of foot ulcers and may provide therapeutic avenues for DFU treatments.
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OBJECTIVE: To understand the effects of nutrition security and social determinants of health (SDOHs) on pressure injury (PI) progression through a scoping review and retrospective review of patients reporting to New England's largest healthcare system. METHODS: Authors performed a scoping review for full-text, original articles reporting outcomes data specific to PIs in patients with socially informed nutrition insecurity. Investigators also performed a retrospective review of all patients from 2012 to 2021 to search for patients with PI documentation and International Classification of Diseases, Tenth Revision Z codes related to the SDOHs. RESULTS: A full-text review of 2,323 articles from 1965 to 2020 failed to locate any eligible studies. Investigators identified 1,044 patients who met the inclusion criteria; 50.7% were men, 74.3% were White, and 13.3% had evidence of detrimental SDOHs. The average PI duration was 12.13 days (interquartile range, 6 days). Multivariate regression analysis revealed that PI duration was longer in men, Black patients, and patients with evidence of detrimental SDOHs compared with their converse counterparts (P < .0001). The presence of detrimental SDOHs independently predicted an increased duration of disease by 13.07 days (95% CI, 8.99-17.15; t = 6.29, P < .0001). CONCLUSIONS: A patient's SDOH history has a significant and considerably stronger correlation with disease progression than predictors that are traditionally studied such as sex, race, or body mass index. These findings are novel, as highlighted by the absence of data uncovered in the literature. These data carry relevance for plastic surgeons wishing to prevent early recurrence following operative closure of PI-related wounds.
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Úlcera por Pressão , Determinantes Sociais da Saúde , Feminino , Humanos , Masculino , Estudos RetrospectivosRESUMO
Significance: The global burden of diabetic wounds, particularly diabetic foot ulcers, continues to have large economic and social impact throughout the world. Current strategies are not sufficient to overcome this burden of disease. Finding newer, more advanced regenerative cell and tissue-based strategies to reduce morbidity remains paramount. Recent Advances: Recent advances in stem cell therapies are discussed. We also highlight the practical issues of translating these advancing technologies into the clinical setting. Critical Issues: We discuss the use of somatic and induced pluripotent stem cells and the stromal vascular fraction, as well as innovations, including the use of 3D bioprinting of skin. We also explore related issues of using regenerative techniques in clinical practice, including the current regulatory landscape and translatability of in vivo research. Future Directions: Advances in stem cell manipulation showcase the best therapeutic resources available to enhance mechanisms of wound healing such as angiogenesis, cell proliferation, and collagen synthesis; potential methods include changing the scaffold microenvironment, including relative oxygen tension, and the use of gene modification and nanotechnology. Secretome engineering, particularly the use of extracellular vesicles, may be another potential cell-derived therapeutic that may enable use of cell-free translational therapy.
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Diabetes Mellitus , Pé Diabético , Células-Tronco Pluripotentes Induzidas , Humanos , Cicatrização , Transplante de Células-Tronco , Pé Diabético/terapia , Pele , Diabetes Mellitus/terapiaRESUMO
Objective: Chronic skin wounds are one of the most devastating complications in diabetic patients due to the formation of advanced glycation end-products (AGEs) resulting from nonenzymatic glycation of proteins and lipids in hyperglycemia. AGEs, upon binding their receptors (RAGEs), trigger proinflammatory signals that impair wound healing in diabetes and contribute to the pathology of chronic skin wounds. Approach: We previously developed a recombinant fusion protein containing the binding domain of RAGE (vRAGE) linked to elastin-like polypeptides (ELPs) that acts as a competitive inhibitor of AGEs, and another ELP fusion protein containing stromal cell-derived factor 1 (SDF1) that promotes revascularization. In this study, we report the effects of protein coacervates incorporating both vRAGE-ELP and SDF1-ELP on wound healing in an in vitro diabetes-mimicking cell culture system, and in in vivo in full-thickness wounds on diabetic mice. Results: The combination of vRAGE-ELP and SDF1-ELP increased cell metabolic activity in AGE-stimulated endothelial cells, promoted in vitro tube formation and accelerated healing in an in vitro cell migration assay. When used in a single topical application on full-thickness excisional skin wounds in diabetic mice, wound closure in the combination groups reached almost 100% on postwounding day 35, compared to 62% and 85% on the same days in animals treated with fibrin gel control and vehicle control consisting of ELP alone. Innovation: To our knowledge, this is the first study that attempts to reverse the AGE-RAGE-mediated signaling as well as to promote cell proliferation and vascularization in one single treatment. Conclusion: The codelivery of vRAGE-ELP and SDF1-ELP has potential for the treatment of diabetic wounds.
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Diabetes Mellitus Experimental , Elastina , Camundongos , Animais , Elastina/química , Células Endoteliais/metabolismo , Peptídeos , Proteínas Recombinantes , Produtos Finais de Glicação AvançadaRESUMO
Responsibilities placed on nurses increased during the COVID-19 pandemic. Hospital-acquired PI monitoring was deferred in favor of more critical patient needs. It was hypothesized that a counterintuitive dip in HAPI reporting would be observed despite maximum hospital capacity across much of the United States. The electronic medical records of patients treated in the YNHH System between December 2017 and February 2021 were retrospectively reviewed to identify patients with HAPIs, defined as PIs not documented upon admission but subsequently present during the patient's hospital stay. Paired t test revealed a significantly lower number of reported incidents mid-pandemic than during the prepandemic baseline months (P <.0001). The data in this report show interdisciplinary clinician-led teams must continue to monitor for HAPIs and congruous conditions to minimize reporting gaps and progression in PI severity despite COVID-19 pandemic-related conditions and additional related responsibilities.
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COVID-19 , Úlcera por Pressão , COVID-19/epidemiologia , Humanos , Doença Iatrogênica , Pandemias , Úlcera por Pressão/epidemiologia , Estudos Retrospectivos , Estados Unidos/epidemiologiaRESUMO
Human-induced pluripotent stem cells (hiPSC) and their differentiated vascular cells have been revolutionizing the field of regenerative wound healing. These cells are shown to be rejuvenated with immense potentials in secreting paracrine factors. Recently, hiPSC-derived vascular smooth muscle cells (hiPSC-VSMC) have shown regenerative wound healing ability via their paracrine secretion. The quest to modulate the secretory function of these hiPSC-VSMC is an ongoing effort and involves the use of both biochemical and biophysical stimuli. This study explores the development and optimization of a reproducible, inexpensive protocol to form hiPSC-VSMC derived spheroids to investigate the implications of spheroid size on viability and paracrine secretion. Our data show the successful formation of different sizes of spheroids using various amount of hiPSC-VSMC. The hiPSC-VSMC spheroids formed with 10,000 cells strike an ideal balance between overall cell health and maximal paracrine secretion. The conditioned medium from these spheroids was found to be bioactive in enhancing human dermal fibroblast cell proliferation and migration. This research will inform future studies on the optimal spheroid size for regenerative wound healing applications.
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Células-Tronco Pluripotentes Induzidas , Diferenciação Celular , Meios de Cultivo Condicionados , Humanos , Músculo Liso Vascular , Miócitos de Músculo Liso , Esferoides CelularesRESUMO
As the surgical community continues to work towards greater diversity, equity, and inclusion, the need for buy-in from all surgeons-including those of the White majority-becomes increasingly apparent. This article invites all surgeons to aid in diversity, equity, and inclusion efforts as "allies," "upstanders," and "champions for change," and provides 2 specific frameworks for enacting allyship within the surgical field. Overt and conscious efforts to embrace allyship are imperative as we seek to fulfill our professional responsibilities to patients and will help create a workplace environment where all persons feel accepted, valued, welcomed, and respected.
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Cirurgiões , HumanosRESUMO
Chronic skin wounds are commonly found in older individuals who have impaired circulation due to diabetes or are immobilized due to physical disability. Chronic wounds pose a severe burden to the health-care system and are likely to become increasingly prevalent in aging populations. Various treatment approaches exist to help the healing process, although the healed tissue does not generally recapitulate intact skin but rather forms a scar that has inferior mechanical properties and that lacks appendages such as hair or sweat glands. This article describes new experimental avenues for attempting to improve the regenerative response of skin using biophysical techniques as well as biochemical methods, in some cases by trying to harness the potential of stem cells, either endogenous to the host or provided exogenously, to regenerate the skin. These approaches primarily address the local wound environment and should likely be combined with other modalities to address regional and systemic disease, as well as social determinants of health.
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Pele , Cicatrização , Idoso , Humanos , Regeneração/fisiologia , Células-Tronco , Cicatrização/fisiologiaRESUMO
Diabetic foot ulceration (DFU) is a devastating complication of diabetes whose pathogenesis remains incompletely understood. Here, we profile 174,962 single cells from the foot, forearm, and peripheral blood mononuclear cells using single-cell RNA sequencing. Our analysis shows enrichment of a unique population of fibroblasts overexpressing MMP1, MMP3, MMP11, HIF1A, CHI3L1, and TNFAIP6 and increased M1 macrophage polarization in the DFU patients with healing wounds. Further, analysis of spatially separated samples from the same patient and spatial transcriptomics reveal preferential localization of these healing associated fibroblasts toward the wound bed as compared to the wound edge or unwounded skin. Spatial transcriptomics also validates our findings of higher abundance of M1 macrophages in healers and M2 macrophages in non-healers. Our analysis provides deep insights into the wound healing microenvironment, identifying cell types that could be critical in promoting DFU healing, and may inform novel therapeutic approaches for DFU treatment.
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Diabetes Mellitus/genética , Pé Diabético/genética , Fibroblastos/metabolismo , Macrófagos/metabolismo , Transcriptoma , Cicatrização/genética , Biomarcadores/metabolismo , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Proteína 1 Semelhante à Quitinase-3/genética , Proteína 1 Semelhante à Quitinase-3/metabolismo , Diabetes Mellitus/metabolismo , Diabetes Mellitus/patologia , Pé Diabético/metabolismo , Pé Diabético/patologia , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Fibroblastos/patologia , Regulação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Queratinócitos/metabolismo , Queratinócitos/patologia , Leucócitos/metabolismo , Leucócitos/patologia , Macrófagos/patologia , Metaloproteinase 1 da Matriz/genética , Metaloproteinase 1 da Matriz/metabolismo , Metaloproteinase 11 da Matriz/genética , Metaloproteinase 11 da Matriz/metabolismo , Metaloproteinase 3 da Matriz/genética , Metaloproteinase 3 da Matriz/metabolismo , Análise de Célula Única/métodos , Pele/metabolismo , Pele/patologia , Sequenciamento do ExomaRESUMO
Significance: Nonhealing wounds are a significant burden for the health care system all over the world. Existing treatment options are not enough to promote healing, highlighting the urgent need for improved therapies. In addition, the current advancements in tissue-engineered skin constructs and stem cell-based therapies are facing significant hurdles due to the absence of a renewable source of functional cells. Recent Advances: Induced pluripotent stem cell technology (iPSC) is emerging as a novel tool to develop the next generation of personalized medicine for the treatment of chronic wounds. The iPSC provides unlimited access to various skin cells to generate complex personalized three-dimensional skin constructs for disease modeling and autologous grafts. Furthermore, the iPSC-based therapies can target distinct wound healing phases and have shown accelerating wound closure by enhancing angiogenesis, cell migration, tissue regeneration, and modulating inflammation. Critical Issues: Since the last decade, iPSC has been revolutionizing the field of wound healing and skin tissue engineering. Despite the current progress, safety and heterogeneity among iPSC lines are still major hurdles in addition to the lack of large animal studies. These challenges need to be addressed before translating an iPSC-based therapy to the clinic. Future Directions: Future considerations should be given to performing large animal studies to check the safety and efficiency of iPSC-based therapy in a wound healing setup. Furthermore, strategies should be developed to overcome variation between hiPSC lines, develop an efficient manufacturing process for iPSC-derived products, and generate complex skin constructs with vasculature and skin appendages.
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Células-Tronco Pluripotentes Induzidas , Medicina Regenerativa , Animais , Células-Tronco Pluripotentes Induzidas/metabolismo , Medicina Regenerativa/métodos , Pele , Engenharia Tecidual/métodos , Cicatrização/fisiologiaRESUMO
iPSC technology is revolutionizing the field of regenerative medicine. The generation of patient-specific cells has huge potential for disease modeling as well as for clinical applications. iPSCs have been used as a renewable source of vascular cells, and in particular vascular smooth muscle cells. The use of these human iPSC-derived vascular smooth muscle cells is attractive for vascular tissue engineering. The cells are used in developing vascular grafts as well as in engineering disease models. Recent studies have shown the proangiogenic potentials of human iPSC-derived vascular smooth muscle cells in treating wounds. Here, we describe the VSMC differentiation protocol from human iPSCs and encapsulation methods in collagen scaffolds to promote proangiogenic potentials.
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Células-Tronco Pluripotentes Induzidas , Diferenciação Celular , Humanos , Músculo Liso Vascular , Miócitos de Músculo Liso , Engenharia Tecidual/métodosRESUMO
Tissue-engineered constructs have immense potential as autologous grafts for wound healing. Despite the rapid advancement in fabrication technology, the major limitation is controlling angiogenesis within these constructs to form a vascular network. Here, we aimed to develop a 3D hydrogel that can regulate angiogenesis. We tested the effect of fibronectin and vascular smooth muscle cells derived from human induced pluripotent stem cells (hiPSC-VSMC) on the morphogenesis of endothelial cells. The results demonstrate that fibronectin increases the number of EC networks. However, hiPSC-VSMC in the hydrogel further substantiated the number and size of EC networks by vascular endothelial growth factor and basic fibroblast growth factor secretion. A mechanistic study shows that blocking αvß3 integrin signaling between hiPSC-VSMC and fibronectin impacts the EC network formation via reduced cell viability and proangiogenic growth factor secretion. Collectively, this study set forth initial design criteria in developing an improved pre-vascularized construct.
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Human-induced pluripotent stem cell-derived-vascular smooth muscle cells (hiPSC-VSMC) and their secretome have been shown to promote angiogenesis and wound healing. However, there is a paucity of research on how the extracellular matrix (ECM) microenvironment may impact the hiPSC-VSMC's functions. In this study, we investigated the effect of specific ECM ligand-integrin interaction on hiPSC-VSMC's paracrine secretion, cell viability, and morphology. Here, we show precise modulation of hiPSC-VSMC in a fibronectin functionalized fibrillar collagen scaffold by targeting their integrin ß3. The secretion of proangiogenic growth factor, basic fibroblast growth factor (bFGF) was found to be fibronectin-dependent via αvß3 integrin interactions. In addition, our data show the possible role of a positive feedback loop between integrin ß3, bFGF, and matrix metalloproteinase-2 in regulating hiPSC-VSMC's morphology and cell viability. Finally, the secretome with enhanced bFGF shows potential for future wound healing applications.