Modular micro-PCR system for the onsite rapid diagnosis of COVID-19.

Effective containment of the COVID-19 pandemic requires rapid and accurate detection of the pathogen. Polymerase chain reaction (PCR) remains the gold standard for COVID-19 confirmation. In this article, we report the performance of a cost-effective modular microfluidic reverse transcription (RT)-PCR and RT-loop mediated isothermal amplification (RT-LAMP) platform, Epidax®, for the point-of-care testing and confirmation of SARS-CoV-2.

Layer-by-layer coated nanoliposomes for oral delivery of insulin.

Crossing the intestinal epithelial cell barrier safely and reaching the blood with therapeutic levels of bioactive insulin have been the ultimate goal of oral insulin delivery. The optimum way to overcome the barrier lies in the design of an efficient high drug loading carrier, that can protect insulin from the harsh Gastrointestinal (GI) environment and enhance its uptake and transport by epithelial cells. In the present study, we developed a multi-layered insulin loading strategy on an anionic nanoliposome surface based on electrostatic interaction with chitosan.

Adventitial injection delivery of nano-encapsulated sirolimus (Nanolimus) to injury-induced porcine femoral vessels to reduce luminal restenosis.

Endovascular therapy in peripheral intervention has grown exponentially in the past decade, but the issue of high restenosis rates in lower extremity arteries still persist. While drug-coated balloons (DCB) have been the device of choice, recent controversary regarding the long-term safety of paclitaxel have raised concern over current DCBs. In our study, we proposed that the direct injection of a sirolimus nanoliposomal formulation (Nanolimus) using a infusion catheter can attenuate inflammation response in injured vessels.

Controlled-release nanotherapeutics: State of translation.

This is a review of nanotherapeutic systems, specifically those that exhibit controlled release of the encapsulated bioactive compound. The survey includes the delivery of a range of bioactive compounds, from lipophilic small molecules to hydrophilic proteins and siRNA molecules. The research into enabling sustained delivery of these compounds from nanocarriers has been prolific, but clinical success has been harder to achieve.

A bilayer swellable drug-eluting ureteric stent: Localized drug delivery to treat urothelial diseases.

A bilayer swellable drug-eluting ureteric stent (BSDEUS) is engineered and implemented, as a sustained drug delivery platform technology that enhances localized drug delivery to the highly impermeable urothelium, for the treatment of urothelial diseases such as strictures and carcinomas. On deployment, the device swells to co-apt with the ureteric wall and ensure drug availability to these tissues. BSDEUS consists of a stent spray-coated with a polymeric drug containing polylactic acid-co-caprolactone (PLC) layer which is overlaid by a swellable polyethylene glycol diacrylate (PEGDA) based hydrogel.

Materials technology in drug eluting balloons: Current and future perspectives.

The coating material technology is important for the delivery of anti-proliferative drugs from the surface of drug-eluting balloons (DEBs), which are emerging as alternatives to drug-eluting stents (DES) in the field of interventional cardiology. Currently, several shortcomings limit their competition with DES, including low drug transfer efficiency to the arterial tissues and undesirable particulate generation from the coating matrix. In this review, we provide a survey of the materials used in existing DEBs, and discussed the mechanisms of actions of both the drugs and coating materials.

Single-step synthesis of heparin-doped polypyrrole nanoparticles for delivery of angiogenic factor.

Aim: To perform one-pot synthesis of heparin-immobilized polypyrrole (PPy) nanoparticles and evaluate the use of these nanoparticles for the delivery of VEGF.

Materials & Methods: Heparin-stabilized synthesis of PPy nanoparticles was performed via oxidative polymerization. VEGF-bound PPy-heparin nanoparticles were delivered to endothelial cells and bioactivity of VEGF was assessed by Matrigel tube formation.

Surface modification of PVDF using non-mammalian sources of collagen for enhancement of endothelial cell functionality.

Although polyvinylidene fluoride (PVDF) is non-toxic and stable in vivo, its hydrophobic surface has limited its bio-applications due to poor cell-material interaction and thrombus formation when used in blood contacting devices. In this study, surface modification of PVDF using naturally derived non-mammalian collagen was accomplished via direct surface-initiated atom transfer radical polymerisation (SI-ATRP) to enhance its cytocompatibility and hemocompatibility. Results showed that Type I collagen was successfully extracted from fish scales and bullfrog skin.

PCL microspheres tailored with carboxylated poly(glycidyl methacrylate)-REDV conjugates as conducive microcarriers for endothelial cell expansion.

Microcarrier cell culture systems provide one of the most promising techniques for cell amplification due to their high surface area-to-volume ratio. In this study, biodegradable polycaprolactone (PCL) microspheres tethered with carboxylated poly(glycidyl methacrylate)-REDV conjugates were developed by a combination of surface-initiated atom transfer radical polymerization (ATRP) and azide-alkyne click chemistry as conducive microcarriers for rapid cell expansion of human umbilical vein endothelial cells (HUVECs). Azido-terminated poly(glycidyl methacrylate) (PGMA-N) brushes were grafted onto the PCL microspheres by surface-initiated ATRP.

Multifunctional REDV-conjugated zwitterionic polycarboxybetaine-polycaprolactone hybrid surfaces for enhanced antibacterial activity, anti-thrombogenicity and endothelial cell proliferation.

Ideal synthetic polymeric vascular scaffolds should provide an excellent physiological environment to facilitate cell adhesion and growth, and appropriate physicochemical properties to prevent thrombogenicity and secondary infection. In the current study, a multifunctional polycaprolactone (PCL) surface for simultaneously enhancing the adhesion and proliferation of endothelial cells (ECs), as well as inhibiting pathogenic microbial adhesion and preserving hemocompatibility was demonstrated. The achievement of such a multifunctional surface was accomplished by the conjugation of Arg-Glu-Asp-Val (REDV) short peptides to zwitterionic polycarboxybetaine brush-grafted PCL films via surface-initiated atom transfer radical polymerization (ATRP).

Development of a miniaturized stimulation device for electrical stimulation of cells.

Background: Directing cell behaviour using controllable, on-demand non-biochemical methods, such as electrical stimulation is an attractive area of research. While there exists much potential in exploring different modes of electrical stimulation and investigating a wider range of cellular phenomena that can arise from electrical stimulation, progress in this field has been slow. The reasons for this are that the stimulation techniques and customized setups utilized in past studies have not been standardized, and that current approaches to study such phenomena rely on low throughput platforms with restricted variability of waveform outputs.

Imparting electroactivity to polycaprolactone fibers with heparin-doped polypyrrole: Modulation of hemocompatibility and inflammatory responses.

Hemocompatibility, anti-inflammation and anti-thrombogenicity of acellular synthetic vascular grafts remains a challenge in biomaterials design. Using electrospun polycaprolactone (PCL) fibers as a template, a coating of polypyrrole (PPy) was successfully polymerized onto the fiber surface. The fibers coated with heparin-doped PPy (PPy-HEP) demonstrated better electroactivity, lower surface resistivity (9-10-fold) and better anti-coagulation response (non-observable plasma recalcification after 30min vs.

Polymer-Enriched 3D Graphene Foams for Biomedical Applications.

Graphene foams (GFs) are versatile nanoplatforms for biomedical applications because of their excellent physical, chemical, and mechanical properties. However, the brittleness and inflexibility of pristine GF (pGF) are some of the important factors restricting their widespread application. Here, a chemical-vapor-deposition-assisted method was used to synthesize 3D GFs, which were subsequently spin-coated with polymer to produce polymer-enriched 3D GFs with high conductivity and flexibility.

RAE1 ligands for the NKG2D receptor are regulated by STING-dependent DNA sensor pathways in lymphoma.

The immunoreceptor NKG2D originally identified in natural killer (NK) cells recognizes ligands that are upregulated on tumor cells. Expression of NKG2D ligands (NKG2DL) is induced by the DNA damage response (DDR), which is often activated constitutively in cancer cells, revealing them to NK cells as a mechanism of immunosurveillance. Here, we report that the induction of retinoic acid early transcript 1 (RAE1) ligands for NKG2D by the DDR relies on a STING-dependent DNA sensor pathway involving the effector molecules TBK1 and IRF3.

Endothelial cell thrombogenicity is reduced by ATRP-mediated grafting of gelatin onto PCL surfaces.

Reducing the thrombogenicity of a tissue-engineered vascular graft prior to implantation is important for improving graft patency. As functionalization of synthetic materials with cell-adhesive proteins is routinely utilized as a means to promote endothelial cell (EC) growth, we conducted detailed investigation on the proliferation and thrombogenicity of ECs on such functionalized surfaces. We observed that polycaprolactone (PCL) surfaces functionalized with poly(glycidyl methacrylate) [(P(GMA)] brushes via atom transfer radical polymerization (ATRP) alone resulted in the enhancement of an activated EC profile characterized by low production of nitric oxide (NO), platelet activation and elevated expression levels of von Willebrand factor (vWF) and matrix metalloproteinase-2 (MMP-2).

Immobilization of gelatin onto poly(glycidyl methacrylate)-grafted polycaprolactone substrates for improved cell-material interactions.

To enhance the cytocompatibility of polycaprolactone (PCL), cell-adhesive gelatin is covalently immobilized onto the PCL film surface via two surface-modified approaches: a conventional chemical immobilization process and a surface-initiated atom transfer radical polymerization (ATRP) process. Kinetics studies reveal that the polymer chain growth from the PCL film using the ATRP process is formed in a controlled manner, and that the amount of immobilized gelatin increases with an increasing concentration of epoxide groups on the grafted P(GMA) brushes. In vitro cell adhesion and proliferation studies demonstrate that cell affinity and growth are significantly improved by the immobilization of gelatin on PCL film surfaces, and that this improvement is positively correlated to the amount of covalently immobilized gelatin.

Differential pulmonary transcriptomic profiles in murine lungs infected with low and highly virulent influenza H3N2 viruses reveal dysregulation of TREM1 signaling, cytokines, and chemokines.

Investigating the relationships between critical influenza viral mutations contributing to increased virulence and host expression factors will shed light on the process of severe pathogenesis from the systems biology perspective. We previously generated a mouse-adapted, highly virulent influenza (HVI) virus through serial lung-to-lung passaging of a human influenza H3N2 virus strain that causes low virulent influenza (LVI) in murine lungs. This HVI virus is characterized by enhanced replication kinetics, severe lung injury, and systemic spread to major organs.