Advanced wound scaffolds that integrate active substances to treat chronic wounds have gained significant recent attention. While wound scaffolds and advanced functionalities have previously been incorporated into one medical device, the wirelessly triggered release of active substances has remained the focus of many research endeavors. To combine multiple functions including light-triggered activation, antiseptic, angiogenic, and moisturizing properties, a 3D printed hydrogel patch encapsulating vascular endothelial growth factor (VEGF) decorated with photoactive and antibacterial tetrapodal zinc oxide (t-ZnO) microparticles is developed. To achieve the smart release of VEGF, t-ZnO is modified by chemical treatment and activated through ultraviolet/ visible light exposure. This process would also make the surface rough and improve protein adhesion. The elastic modulus and degradation behavior of the composite hydrogels, which must match the wound healing process, are adjusted by changing t-ZnO concentrations. The t-ZnO-laden composite hydrogels can be printed with any desired micropattern to potentially create a modular elution of various growth factors. The VEGF-decorated t-ZnO-laden hydrogel patches show low cytotoxicity and improved angiogenic properties while maintaining antibacterial functions in vitro. In vivo tests show promising results for the printed wound patches, with less immunogenicity and enhanced wound healing.
Bariatric and metabolic surgery has shown to promote weight loss and reduce systemic inflammation. However, the sequence and timing of events regarding metabolic improvement and inflammation resolution has been rarely explored. Furthermore, data on inflammatory markers of Th17 and Th1 cell responses after bariatric surgery is scarce. We conducted a prospective study in subjects with obesity that underwent bariatric and metabolic surgery, with follow-ups at 3 and 6 months. Anthropometric and metabolic markers such as insulin levels, HOMA-IR, and lipid parameters declined significantly 3 months after surgery; while hs-CRP, TNF-α, IL-1β, IL-6, and IL-8 serum concentrations decreased 6 months after the procedure. Concentrations of Th1 signature and driver cytokines, particularly IFN-γ, IL-12, and IL-18, and of Th17 driver IL-23 also decreased significantly after 6 months. Significant positive correlations between triglyceride levels and hs-CRP, IL-1β, and IFN-γ concentrations, and between Apo B and IFN-γ levels were observed 6 months after bariatric and metabolic surgery. In addition, BMI was associated with hs-CRP and TNF-α concentrations. Fat mass correlated with hs-CRP, TNF-α, and IL-12. Analysis of the temporality of metabolic and inflammatory events suggests that improvement in the metabolic status occurs before resolution of systemic inflammation and may be a requisite for the later event.
Recapitulating inherent heterogeneity and complex microarchitectures within confined print volumes for developing implantable constructs that could maintain their structure in vivo has remained challenging. Here, we present a combinational multimaterial and embedded bioprinting approach to fabricate complex tissue constructs that can be implanted postprinting and retain their three-dimensional (3D) shape in vivo. The microfluidics-based single nozzle printhead with computer-controlled pneumatic pressure valves enables laminar flow-based voxelation of up to seven individual bioinks with rapid switching between various bioinks that can solve alignment issues generated during switching multiple nozzles. To improve the spatial organization of various bioinks, printing fidelity with the z-direction, and printing speed, self-healing and biodegradable colloidal gels as support baths are introduced to build complex geometries. Furthermore, the colloidal gels provide suitable microenvironments like native extracellular matrices (ECMs) for achieving cell growths and fast host cell invasion via interconnected microporous networks in vitro and in vivo. Multicompartment microfibers (i.e., solid, core−shell, or donut shape), composed of two different bioink fractions with various lengths or their intravolume space filled by two, four, and six bioink fractions, are successfully printed in the ECM-like support bath. We also print various acellular complex geometries such as pyramids, spirals, and perfusable branched/linear vessels. Successful fabrication of vascularized liver and skeletal muscle tissue constructs show albumin secretion and bundled muscle mimic fibers, respectively. The interconnected microporous networks of colloidal gels result in maintaining printed complex geometries while enabling rapid cell infiltration, in vivo.
Engineering three-dimensional (3D) sensible tissue constructs, along with the complex microarchitecture wiring of the sensory nervous system, has been an ongoing challenge in the tissue engineering field. By combining 3D bioprinting and human pluripotent stem cell (hPSC) technologies, sensible tissue constructs could be engineered in a rapid, precise, and controllable manner to replicate 3D microarchitectures and mechanosensory functionalities of the native sensory tissue (e.g. response to external stimuli). Here, we introduce a biofabrication approach to create complex 3D microarchitecture wirings. We develop an hPSC-sensory neuron (SN) laden bioink using highly purified and functional SN populations to 3D bioprint microarchitecture wirings that demonstrate responsiveness to warm/cold sense-inducing chemicals and mechanical stress. Specifically, we tailor a conventional differentiation strategy to our purification method by utilizing p75 cell surface marker and DAPT treatment along with neuronal growth factors in order to selectively differentiate neural crest cells into SNs. To create spatial resolution in 3D architectures and grow SNs in custom patterns and directions, an induced pluripotent stem cell (iPSC)-SN-laden gelatin bioink was printed on laminin-coated substrates using extrusion-based bioprinting technique. Then the printed constructs were covered with a collagen matrix that guided SNs growing in the printed micropattern. Using a sacrificial bioprinting technique, the iPSC-SNs were seeded into the hollow microchannels created by sacrificial gelatin ink printed in the gelatin methacryloyl supporting bath, thereby demonstrating controllability over axon guidance in curved lines up to several tens of centimeters in length on 2D substrates and in straight microchannels in 3D matrices. Therefore, this biofabrication approach could be amenable to incorporate sensible SN networks into the engineered skin equivalents, regenerative skin implants, and augmented somatosensory neuro-prosthetics that have the potential to regenerate sensible functions by connecting host neuron systems in injured areas.
Benign vascular neoplasms are common clinical problems encountered in the practice of primary care. Pyogenic granulomas are one of the most common benign vascular lesions in young adults. Although the physiopathological mechanism for the development of this condition is still not well understood, it has been commonly associated with several triggers such as treatment with retinoids, biological agents, invasive cutaneous therapies and trauma. The development of pyogenic granulomas on sites of vascular malformations like port wine stains has been described in the literature to occur rarely. Most of these types of cases have been studied to occur in the setting of pregnancy and after cryotherapy or pulsated laser therapy. The aim of this article is to present the case of a 21-year-old man with a recent appearance of a pyogenic granuloma within an underlying port wine stain in the posterior cervical region without any history of triggers or risk factors. Excision of the vascular lesion was done, and histopathological report confirmed the diagnosis. The objective of this manuscript is to discuss the possible mechanisms involved in the development of this uncommon presentation and to summarize the current literature related to this clinical scenario.
In article number 2007555, Leonard Siebert, Eunjung Lee, Su Ryon Shin, and co‐workers develop a 3D printed smart wound scaffold encapsulating growth factors decorated with light‐sensitive and antibacterial tetrapodal zinc oxide (t‐ZnO) microparticles for the treatment of chronic wounds. The multifunctional pro perties of the smart scaffold combined with light‐triggered angiogenic factor release, antibacterial properties, and tissue compatibility enable fast wound recovery.
Varicella-zoster virus is a pathogenic virus that can present itself as a primary infection or secondary infection, also known as herpes zoster. Recently, there has been a re-emergence of this vaccine-preventable disease due to gaps in vaccination. Primary varicella in immunocompetent adults is highly uncommon, and it could result in severe complications within this population. Given this delicate scenario, family physicians should be well trained to recognize the characteristic cutaneous lesions of varicella and dictate adequate management for these patients to obtain the best possible outcome and prevent life-threatening complications. We present the case of a 43-year-old immunocompetent woman with the onset of a generalized pruritic dermatosis characterized primarily by the presence of macules, vesicles, and crusts. The patients' lesions were compatible with primary varicella, and serological studies confirmed the diagnosis. Given the absence of acute complications in this individual, supportive treatment and close follow-up were the therapeutic modalities. This article focuses on the educational discussion of the primary differential diagnosis, evaluation for possible complications, and management of this uncommon clinical scenario. We also reinforce the importance of immunization in preventing re-emergent diseases as a critical element within primary care management.
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