Hemorrhage and bacterial infections are major hurdles in the management of life‐threatening surgical wounds. Most bioadhesives for wound closure lack sufficient hemostatic and antibacterial ...properties. Furthermore, they suffer from weak sealing efficacy, particularly for stretchable organs, such as the lung and bladder. Accordingly, there is an unmet need for mechanically robust hemostatic sealants with simultaneous antibacterial effects. Here, an injectable, photocrosslinkable, and stretchable hydrogel sealant based on gelatin methacryloyl (GelMA), supplemented with antibacterial zinc ferrite (ZF) nanoparticles and hemostatic silicate nanoplatelets (SNs) for rapid blood coagulation is nanoengineered. The hydrogel reduces the in vitro viability of Staphylococcus aureus by more than 90%. The addition of SNs (2% w/v) and ZF nanoparticles (1.5 mg mL−1) to GelMA (20% w/v) improves the burst pressure of perforated ex vivo porcine lungs by more than 40%. Such enhancement translated to ≈250% improvement in the tissue sealing capability compared with a commercial hemostatic sealant, Evicel. Furthermore, the hydrogels reduce bleeding by ≈50% in rat bleeding models. The nanoengineered hydrogel may open new translational opportunities for the effective sealing of complex wounds that require mechanical flexibility, infection management, and hemostasis.
An injectable, photocrosslinkable, and stretchable tissue sealant is developed using a gelatin methacryloyl hydrogel, supplemented with zinc ferrite nanoparticles and silicate nanoplatelets. It improves tissue adhesion by ≈250% compared with a commercial sealant and reduces bleeding by ≈50% in rat models. This engineered hydrogel platform may open new translational opportunities for the effective sealing of complex wounds that require mechanical flexibility, infection management, and hemostasis.
Despite many efforts to fabricate high-aspect-ratio atomic force microscopy (HAR-AFM) probes for high-fidelity, high-resolution topographical imaging of three-dimensional (3D) nanostructured ...surfaces, current HAR probes still suffer from unsatisfactory performance, low wear-resistivity, and extravagant prices. The primary objective of this work is to demonstrate a novel design of a high-resolution (HR) HAR AFM probe, which is fabricated through a reliable, cost-efficient benchtop process to precisely implant a single ultrasharp metallic nanowire on a standard AFM cantilever probe. The force–displacement curve indicated that the HAR-HR probe is robust against buckling and bending up to 150 nN. The probes were tested on polymer trenches, showing a much better image fidelity when compared with standard silicon tips. The lateral resolution, when scanning a rough metal thin film and single-walled carbon nanotubes (SW-CNTs), was found to be better than 8 nm. Finally, stable imaging quality in tapping mode was demonstrated for at least 15 continuous scans indicating high resistance to wear. These results demonstrate a reliable benchtop fabrication technique toward metallic HAR-HR AFM probes with performance parallel or exceeding that of commercial HAR probes, yet at a fraction of their cost.
The human brain and central nervous system (CNS) present unique challenges in drug development for neurological diseases. One major obstacle is the blood–brain barrier (BBB), which hampers the ...effective delivery of therapeutic molecules into the brain while protecting it from blood‐born neurotoxic substances and maintaining CNS homeostasis. For BBB research, traditional in vitro models rely upon Petri dishes or Transwell systems. However, these static models lack essential microenvironmental factors such as shear stress and proper cell–cell interactions. To this end, organ‐on‐a‐chip (OoC) technology has emerged as a new in vitro modeling approach to better recapitulate the highly dynamic in vivo human brain microenvironment so‐called the neural vascular unit (NVU). Such BBB‐on‐a‐chip models have made substantial progress over the last decade, and concurrently there has been increasing interest in modeling various neurological diseases such as Alzheimer's disease and Parkinson's disease using OoC technology. In addition, with recent advances in other scientific technologies, several new opportunities to improve the BBB‐on‐a‐chip platform via multidisciplinary approaches are available. In this review, an overview of the NVU and OoC technology is provided, recent progress and applications of BBB‐on‐a‐chip for personalized medicine and drug discovery are discussed, and current challenges and future directions are delineated.
Organ‐on‐a‐chip technology has emerged as a new in vitro modeling approach to recapitulate the human blood–brain barrier (BBB), and BBB‐on‐a‐chip has made substantial progress over the last decade. In this review, an overview of the BBB‐on‐a‐chip models is provided, recent progress and key applications are discussed, current challenges are presented, and future directions are proposed.
Real-time monitoring of human health can be significantly improved by designing novel electronic skin (E-skin) platforms that mimic the characteristics and sensitivity of human skin. A high-quality ...E-skin platform that can simultaneously monitor multiple physiological and metabolic biomarkers without introducing skin irritation is an unmet medical need. Conventional E-skins are either monofunctional or made from elastomeric films that do not include key synergistic features of natural skin, such as multi-sensing, breathability, and thermal management capabilities in a single patch. Herein, we engineered and demonstrated a biocompatible and biodegradable E-skin patch based on flexible gelatin methacryloyl aerogel (FGA) for non-invasive and continuous monitoring of multiple biomarkers of interest. Taking advantage of cryogenic temperature treatment and slow polymerization, we fabricated FGA with a highly interconnected porous structure that displays good flexibility, passive-cooling capabilities, and ultra-lightweight properties that make it comfortable to wear for long periods of time. It also provides numerous permeable capillary channels for thermal-moisture transfer, ensuring its excellent breathability. Therefore, the engineered FGA-based E-skin can simultaneously monitor body temperature, hydration, and biopotentials
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electrophysiological sensors and detect glucose, lactate, and alcohol levels
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electrochemical sensors. This work offers a previously unexplored materials strategy for next-generation E-skin platforms with superior practicality.
A breathable, passive-cooling, non-inflammatory, biodegradable, and flexible aerogel electronic skin is developed to monitor physical, electrophysiological, and metabolic biomarkers from the human body continuously and simultaneously.
•We compare the efficacy of bioinspired nanomaterials with that of existing conventional dressings.•We discuss the anti-microbial and anti-biofilms activities of bioinspired nanomaterials in ...promoting wound healing.•We review approaches used to target bioinspired nanomaterials for delivery at wound sites.
Chronic wounds are ubiquitously inhabited by bacteria, and they remain a challenge as they cause significant discomfort and because their treatment consumes huge clinical resources. To reduce the burden that chronic wounds place upon both patients and health services, a wide variety of approaches have been devised and investigated. Bioinspired nanomaterials have shown great success in wound healing when compared to existing approaches, showing better ability to mimic natural extracellular matrix (ECM) components and thus to promote cell adhesion, proliferation, and differentiation. Wound dressings that are based on bioinspired nanomaterials can be engineered to promote anti-inflammatory mechanisms and to inhibit the formation of microbial biofilms. We consider the extensive potential of bioinspired nanomaterials in wound healing, revealing a scope beyond that covered previously.
Hepatocellular carcinoma (HCC) is a malignant and deadly form of liver cancer with limited treatment options. Transcatheter arterial chemoembolization, a procedure that delivers embolic and ...chemotherapeutic agents through blood vessels, is a promising cancer treatment strategy. However, it still faces limitations, such as inefficient agent delivery and the inability to address tumor‐induced immunosuppression. Here, a drug‐eluting shear‐thinning hydrogel (DESTH) loaded with chemotherapeutic and immunotherapeutic agents in nanocomposite hydrogels composed of gelatin and nanoclays is presented as a therapeutic strategy for a catheter‐based endovascular anticancer approach. DESTH is manually deliverable using a conventional needle and catheter. In addition, drug release studies show a sustained and pH‐dependent co‐delivery of the chemotherapy doxorubicin (acidic pH) and the immune‐checkpoint inhibitor aPD‐1 (neutral pH). In a mouse liver tumor model, the DESTH‐based chemo/immunotherapy combination has the highest survival rate and smallest residual tumor size. Finally, immunofluorescence analysis confirms that DESTH application enhances cell death and increases intratumoral infiltration of cytotoxic T‐cells. In conclusion, the results show that DESTH, which enables efficient ischemic tumor cell death and effective co‐delivery of chemo‐ and immunotherapeutic agents, may have the potential to be an effective therapeutic modality in the treatment of HCC.
In this article, drug‐eluting shear‐thinning hydrogel (DESTH) loaded with chemotherapeutic and immunotherapeutic agents in nanocomposite hydrogels is described as a therapeutic strategy for a catheter‐based endovascular anticancer approach. The results show that DESTH, which enables efficient ischemic cell death and effective co‐delivery of chemo‐ and immunotherapeutic agents, has the potential to become a therapeutic modality for hepatocellular carcinoma.
Viral infection is one of the leading causes of mortality worldwide. The growth of globalization significantly increases the risk of virus spreading, making it a global threat to future public ...health. In particular, the ongoing coronavirus disease 2019 (COVID‐19) pandemic outbreak emphasizes the importance of devices and methods for rapid, sensitive, and cost‐effective diagnosis of viral infections in the early stages by which their quick and global spread can be controlled. Micro and nanoscale technologies have attracted tremendous attention in recent years for a variety of medical and biological applications, especially in developing diagnostic platforms for rapid and accurate detection of viral diseases. This review addresses advances of microneedles, microchip‐based integrated platforms, and nano‐ and microparticles for sampling, sample processing, enrichment, amplification, and detection of viral particles and antigens related to the diagnosis of viral diseases. Additionally, methods for the fabrication of microchip‐based devices and commercially used devices are described. Finally, challenges and prospects on the development of micro and nanotechnologies for the early diagnosis of viral diseases are highlighted.
Viral infections are the leading causes of mortality worldwide. Micro and nanoscale technologies have been used to develop diagnostic platforms for rapid and accurate detection of viral diseases. Here, these technologies are reviewed for sampling, sample processing, enrichment, amplification, and detection of viral particles and antigens. Challenges and future directions in this area are highlighted.
M@RF-COOH (M=Au nanoparticle to AuPt nanoalloys with controlled compositions and sizes, up to Pt nanoparticles) are facilely obtained and their support in a radial mesoporous silica shell is ...simultaneously realized, with the corresponding M@RF-COOH submicrospheres as templates. The upper series are M@RF-COOH submicrospheres, and the under series are M@SiO2 submicrospheres. Display omitted
•Noble nanoparticles (Au, Pt or AuPt) are easily encapsulated in hollow space of SiO2 submicrospheres.•AuPt@SiO2 show activity for epoxidation of styrene with conversion and selectivity of 74% and 85%.•The approach reported in this study simplify the fabrication process of noble metal nanoalloys.
Noble metal nanocrystals (Au, Pt or AuPt) with controlled compositions and nanostructures were embedded into hollow silica submicrospheres with highly ordered radial mesopores through a one-step sol–gel process. 2,4-Dihydroxybenzoic acid–formaldehyde (RF-COOH) resin submicrospheres were utilized simultaneously as a hard template to create hollow interiors inside the silica submicrospheres and as carriers to transport pregrown metal nanocrystals, including Au nanoparticle (NP), Pt NP, and AuPt nanoalloy, into the submicrospheres. Calcination removes the resin submicrospheres and causes metal nanocrystals embedded into the RF-COOH submicrospheres break into multiple smaller nanoparticles (2–6nm) that are randomly dispersed in the hollow space of SiO2 submicrospheres M@SiO2 (M=Au, Pt or AuPt). The AuPt@SiO2 submicrospheres showed good catalytic performance for epoxidation of styrene with the conversion and selectivity of 74% and 85%, respectively. The approach reported in this study could potentially be used to simplify the fabrication process of noble metal nanoalloys, which usually entails multiple steps and a previously synthesized hard metal template, and thus guide the design and creation of high-performance catalysts.
The remarkable ability of biological systems to sense and adapt to complex environmental conditions has inspired new materials and novel designs for next-generation wearable devices. Hydrogels are ...being intensively investigated for their versatile functions in wearable devices due to their superior softness, biocompatibility, and rapid stimulus response. This review focuses on recent strategies for developing bioinspired hydrogel wearable devices that can accommodate mechanical strain and integrate seamlessly with biological systems. We will provide an overview of different types of bioinspired hydrogels tailored for wearable devices. Next, we will discuss the recent progress of bioinspired hydrogel wearable devices such as electronic skin and smart contact lenses. Also, we will comprehensively summarize biosignal readout methods for hydrogel wearable devices as well as advances in powering and wireless data transmission technologies. Finally, current challenges facing these wearable devices are discussed, and future directions are proposed.
The contact lens (CL) industry has made great strides in improving CL‐wearing experiences. However, a large amount of CL wearers continue to experience ocular dryness, known as contact lens‐induced ...dry eye (CLIDE), stemming from the reduction in tear volume, tear film instability, increased tear osmolarity followed by inflammation and resulting in ocular discomfort and visual disturbances. In this article, to address tear film thinning between the CL and the ocular surface, the concept of using a CL with microchannels to deliver the tears from the pre‐lens tear film (PrLTF) to the post‐lens ocular surface using in vitro eye‐blink motion is investigated. This study reports an eye‐blink mimicking system with microfluidic poly(2‐hydroxyethyl methacrylate) (poly(HEMA)) hydrogel with integrated microchannels to demonstrate eye‐blink assisted flow through microchannels. This in vitro experimental study provides a proof‐of‐concept result that tear transport from PrLTF to post‐lens tear film can be enhanced by an artificial eyelid motion in a pressure range of 0.1–5 kPa (similar to human eyelid pressure) through poly(HEMA) microchannels. Simulation is conducted to support the hypothesis. This work demonstrates the feasibility of developing microfluidic CLs with the potential to help prevent or minimize CLIDE and discomfort by the enhanced transport of pre‐lens tears to the post‐lens ocular surface.
The soft contact lens can cause eye dryness and discomfort. This proof‐of‐concept work reports a novel microfluidic contact lens integrated with microchannels to maintain tear flow between the CL and ocular surface. External eyelid pressure is demonstrated to enhance the tear exchange between the pre‐lens tear film and the post‐lens tear film through the microfluidic contact lens.
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