Hyaluronic-Acid-Tagged Cubosomes Deliver Cytotoxics Specifically to CD44-Positive Cancer Cells.

Delivery of chemotherapy drugs specifically to cancer cells raises local drug doses in tumors and therefore kills more cancer cells while reducing side effects in other tissues, thereby improving oncological and quality of life outcomes. Cubosomes, liquid crystalline lipid nanoparticles, are potential vehicles for delivery of chemotherapy drugs, presenting the advantages of biocompatibility, stable encapsulation, and high drug loading of hydrophobic or hydrophilic drugs. However, active targeting of drug-loaded cubosomes to cancer cells, as opposed to passive accumulation, remains relatively underexplored. We formulated and characterized cubosomes loaded with potential cancer drug copper acetylacetonate and functionalized their surfaces using click chemistry coupling with hyaluronic acid (HA), the ligand for the cell surface receptor CD44. CD44 is overexpressed in many cancer types including breast and colorectal. HA-tagged, copper-acetylacetonate-loaded cubosomes have an average hydrodynamic diameter of 152 nm, with an internal nanostructure based on the space group Im3m. These cubosomes were efficiently taken up by two CD44-expressing cancer cell lines (MDA-MB-231 and HT29, representing breast and colon cancer) but not by two CD44-negative cell lines (MCF-7 breast cancer and HEK-293 kidney cells). HA-tagged cubosomes caused significantly more cell death than untargeted cubosomes in the CD44-positive cells, demonstrating the value of the targeting. CD44-negative cells were equally relatively resistant to both, demonstrating the specificity of the targeting. Cell death was characterized as apoptotic. Specific targeting and cell death were evident in both 2D culture and 3D spheroids. We conclude that HA-tagged, copper-acetylacetonate-loaded cubosomes show great potential as an effective therapeutic for selective targeting of CD44-expressing tumors.

Integration of Point-of-Care Ultrasound Education Into the Internal Medicine Core Clerkship Experience.

Point-of-care ultrasound (POCUS) is becoming an essential skill for internists. To date, there are no professional guidelines for how POCUS skills should be taught to medical students. A panel of POCUS experts from seven academic medical centers in the United States was convened to describe the components of independently developed IM clerkship POCUS training programs, identify areas of similarity and difference, and propose recommendations for alignment.

Affimer-Based Europium Chelates Allow Sensitive Optical Biosensing in a Range of Human Disease Biomarkers.

The protein biomarker measurement has been well-established using ELISA (enzyme-linked immunosorbent assay), which offers good sensitivity and specificity, but remains slow and expensive. Certain clinical conditions, where rapid measurement or immediate confirmation of a biomarker is paramount for treatment, necessitate more rapid analysis. Biosensors offer the prospect of reagent-less, processing-free measurements at the patient's bedside. Here, we report a platform for biosensing based on chelated Eu3+ against a range of proteins including biomarkers of cardiac injury (human myoglobin), stroke (glial fibrillary acidic protein (GFAP)), inflammation (C-reactive protein (CRP)) and colorectal cancer (carcinoembryonic antigen (CEA)). The Eu3+ ions are chelated by modified synthetic binding proteins (Affimers), which offer an alternative targeting strategy to existing antibodies. The fluorescence characteristics of the Eu3+ complex with modified Affimers against human myoglobin, GFAP, CRP and CEA were measured in human serum using λex = 395 nm, λem = 590 and 615 nm. The Eu3+-Affimer based complex allowed sensitive detection of human myoglobin, GFAP, CRP and CEA proteins as low as 100 fM in (100-fold) diluted human serum samples. The unique dependence on Eu3+ fluorescence in the visible region (590 and 615 nm) was exploited in this study to allow rapid measurement of the analyte concentration, with measurements in 2 to 3 min. These data demonstrate that the Affimer based Eu3+ complexes can function as nanobiosensors with potential analytical and diagnostic applications.

Development of a Ru Nanoparticle Loaded Thiol Functionalized Meso Porous Silica Modified Screen Printed Au Electrode for Electrochemical Detection and Estimation of Glucose.

Here we report the development of a glucose sensor based on electrochemical detection. The working electrode was a screen printed Au electrode, which was modified with Ru nanoparticle loaded thiol functionalized mesoporous silica. This sensor demonstrated its capability of detecting and estimating glucose concentration in aqueous medium over a wide range of concentration with high sensitivity, durability and reproducibility.

Biosensors for whole-cell bacterial detection.

Bacterial pathogens are important targets for detection and identification in medicine, food safety, public health, and security. Bacterial infection is a common cause of morbidity and mortality worldwide. In spite of the availability of antibiotics, these infections are often misdiagnosed or there is an unacceptable delay in diagnosis. Current methods of bacterial detection rely upon laboratory-based techniques such as cell culture, microscopic analysis, and biochemical assays. These procedures are time-consuming and costly and require specialist equipment and trained users. Portable stand-alone biosensors can facilitate rapid detection and diagnosis at the point of care. Biosensors will be particularly useful where a clear diagnosis informs treatment, in critical illness (e.g., meningitis) or to prevent further disease spread (e.g., in case of food-borne pathogens or sexually transmitted diseases). Detection of bacteria is also becoming increasingly important in antibioterrorism measures (e.g., anthrax detection). In this review, we discuss recent progress in the use of biosensors for the detection of whole bacterial cells for sensitive and earlier identification of bacteria without the need for sample processing. There is a particular focus on electrochemical biosensors, especially impedance-based systems, as these present key advantages in terms of ease of miniaturization, lack of reagents, sensitivity, and low cost.

Low-dose methotrexate toxicity leading to pancytopenia: leucovorin as a rescue treatment.

Low-dose methotrexate has several known side effects associated with mild toxicity including nausea, oral ulcers, and anemia. However, it is rare for patients taking low-dose methotrexate to present with symptoms of severe toxicity including pancytopenia, macular punctate rash, and severe stomatitis. Here we present an 83-year-old patient with a history of rheumatoid arthritis on low-dose methotrexate for 1 year presenting with 5 days of worsening facial swelling, oral lesions, and a macular rash to the extremities. Initial workup revealed severe leukopenia, thrombocytopenia, and previously undiagnosed chronic kidney injury. Computed tomography showed edema surrounding a left maxillary dental implant suggestive of infection. The patient was admitted for suspected methotrexate toxicity complicated by possible dental infection. Methotrexate was withheld. The patient's stomatitis and facial swelling improved with administration of folate, leucovorin, and piperacillin/tazobactam. The patient's severe neutropenia gradually resolved following administration of granulocyte colony-stimulating factor. Infectious workup was negative throughout admission. This case report details factors that precipitate severe methotrexate toxicity at low doses.

Photoactive imaging and therapy for colorectal cancer using a CEA-Affimer conjugated Foslip nanoparticle.

Theranostic nanoparticles hold promise for simultaneous imaging and therapy in colorectal cancer. Carcinoembryonic antigen can be used as a target for these nanoparticles because it is overexpressed in most colorectal cancers. Affimer reagents are synthetic proteins capable of binding specific targets, with additional advantages over antibodies for targeting. We fabricated silica nanoparticles using a water-in-oil microemulsion technique, loaded them with the photosensitiser Foslip, and functionalised the surface with anti-CEA Affimers to facilitate fluorescence imaging and photodynamic therapy of colorectal cancer. CEA-specific fluorescence imaging and phototoxicity were quantified in colorectal cancer cell lines and a LS174T murine xenograft colorectal cancer model. Anti-CEA targeted nanoparticles exhibited CEA-specific fluorescence in the LoVo, LS174T and HCT116 cell lines when compared to control particles (p < 0.0001). No toxicity was observed in LS174T cancer mouse xenografts or other organs. Following photo-irradiation, the anti-CEA targeted particles caused significant cell death in LoVo (60%), LS174T (90%) and HCT116 (70%) compared to controls (p < 0.0001). Photodynamic therapy (PDT) at 24 h in vivo showed a 4-fold reduction in tumour volume compared to control mouse xenografts (p < 0.0001). This study demonstrates the efficacy of targeted fluorescence imaging and PDT using Foslip nanoparticles conjugated to anti-CEA Affimer nanoparticles in in vitro and in vivo colorectal cancer models.

Novel impedimetric immunosensor for detection of pathogenic bacteria Streptococcus pyogenes in human saliva.

Streptococcus pyogenes , also known as group A streptococcus (GAS), is a Gram positive human pathogen responsible for invasive and noninvasive human infections with a high incidence rate. Traditional detection methods involve cell culture and PCR, which are limited by long processing times or the need for high cost equipment. Impedance-based electrochemical immunosensors provide an alternative by which precise and rapid quantitative detection of the organism can help with rapid clinical decisions. To bring a biosensor for point-of-care applications to market, strict optimization of each level of construction and operation is required. In this paper, commercial screen-printed gold electrodes have been used to construct polytyramine (Ptyr)-based immunosensors. Biotin tagged whole antibodies against S. pyogenes were conjugated to Ptyr amine group via biotin-NeutrAvidin coupling. Sensors were optimized at each level of construction, particularly for Ptyr electrodeposition and antibody concentration, to optimize signal and specificity. Scanning electron microscopy, fluorescence microscopy, and on-sensor analysis (HRP conjugated enhanced chemiluminescence-based semiquantitative method) to detect Ptyr surface amine and bound antibody were performed as supporting techniques. Cumulative and single shot incubations had shown detection range of 100 to 10(5) cells per 10 µL and 100 to 10(4) cells per 10 µL of bacteria in PBS, respectively. Sensors were also able to specifically detect S. pyogenes in 50% (v/v) human saliva, with good selectivity and low cross-reactivity.

Diagnosis and Outcomes of Fungal Co-Infections in COVID-19 Infections: A Retrospective Study.

The SARS-CoV-2 pandemic has resulted in a public health emergency with unique complications such as the development of fungal co-infections. The diagnosis of fungal infections can be challenging due to confounding imaging studies and difficulty obtaining histopathology. In this retrospective study, 173 patients with COVID-19 receiving antifungal therapy due to concern for fungal co-infection were evaluated. Patient characteristics, clinical outcomes, and the utility of fungal biomarkers were then evaluated for continuation of antifungal therapy. Data were collected from the electronic health record (EPIC) and analyzed using SPSS (version. 28, IBM, Inc., Armonk, NY, USA) Data are presented as mean ± SD or percentages. A total of 56 COVID-19 patients were diagnosed with fungal co-infection and 117 COVID-19 + patients had no fungal infection. Significantly fewer female patients were in the fungal+ group compared to COVID-19 control patients (29% in fungal+ compared to 51% in controls p = 0.005). Fungal diagnostics were all significantly higher in fungal+ patients. These include 1,4-beta-D-glucan (BDG), fungal culture, and bronchoalveolar lavage galactomannan (BAL GM). Intensive care unit hospitalization, mechanical ventilation, and mortality in fungal+ patients with COVID-19 were significantly higher than in control patients. Finally, significantly more fungal+ patients received voriconazole, isavuconazonium, or amphotericin B therapies, whereas control patients received significantly more short-course fluconazole. COVID-19+ patients with fungal co-infection were significantly more likely to be in the ICU and mechanically ventilated, and they result in higher mortality compared to control COVID-19 patients. The use of fungal diagnostics markers were helpful for diagnosis.

Bevacizumab combined with platinum-based chemotherapy in primary or relapsed ovarian cancer patients: Meta-analysis and literature to review.

Introduction: Earlier, patients with advanced ovarian cancer were treated with a combination of cytoreductive surgery and platinum-based chemotherapy, which had significant outcomes in the past until an increase in relapse and resistance to treatment, which led to the use or development of bevacizumab (a vascular endothelial growth factor inhibitor) in the treatment of primary or relapsed ovarian cancer. Method and Methodology: This study includes five-phase three randomized controlled clinical trials designed to study the impact of bevacizumab in combination with platinum-based chemotherapy compared with platinum-based chemotherapy alone. Results: This study demonstrated significant improvement in the progression-free span but no improvement in overall survival in the treatment group when compared with the control group. Also, adverse effects reported with combination therapy were tolerable and easily manageable by decreasing the infusion rate or by decreasing the frequency of infusion.

Flow cell design for effective biosensing.

The efficiency of three different biosensor flow cells is reported. All three flow cells featured a central channel that expands in the vicinity of the sensing element to provide the same diameter active region, but the rate of channel expansion and contraction varied between the designs. For each cell the rate at which the analyte concentration in the sensor chamber responds to a change in the influent analyte concentration was determined numerically using a finite element model and experimentally using a flow-fluorescence technique. Reduced flow cell efficiency with increasing flow rates was observed for all three designs and was related to the increased importance of diffusion relative to advection, with efficiency being limited by the development of regions of recirculating flow (eddies). However, the onset of eddy development occurred at higher flow rates for the design with the most gradual channel expansion, producing a considerably more efficient flow cell across the range of flow rates considered in this study. It is recommended that biosensor flow cells be designed to minimize the tendency towards, and be operated under conditions that prevent the development of flow recirculation.

Bilateral Endogenous Bacterial Endophthalmitis Secondary to Methicillin-Resistant Staphylococcus aureus (MRSA) Bacteremia.

Endogenous bacterial endophthalmitis (EBE) is a rare but vision-threatening complication of bacteria spreading contiguously through the blood-ocular border. The condition is frequently associated with a poor visual prognosis and has even resulted in death. We present a case of a 48-year-old female with bilateral endogenous methicillin-resistant Staphylococcus aureus (MRSA)endophthalmitis further complicated by septic emboli, endocarditis, osteomyelitis, and septic polyarthralgia. Her vision did not return despite aggressive antibiotic therapy and urgent bilateral vitrectomy. This case presents an interesting and rare clinical vignette resulting in infection and damage of multiple organ systems that required aggressive management and carefully orchestrated multidisciplinary care.

Surface modified hexagonal upconversion nanoparticles for the development of competitive assay for biodetection.

Up-conversion nanoparticles (UCNPs) of sodium yttrium fluoride with ytterbium and erbium ions as sensitizer and activator (ß-NaYF4/Yb3+/Er3+) have been synthesised by a solvothermal method. The synthesised particles were found to be highly uniform in size (~50 nm) and of hexagonal crystal phase producing strong up-conversion luminescence dominated in the green wavelength region. During the synthesis, photoluminescence properties of the reaction mixture were monitored at regular intervals to ensure the required particle size distribution and luminescence efficiency. The hydrophobic particles thus obtained were modified by coating with silica, yielding particles that were stable in aqueous media. The silica coated UCNPs were further modified with maleimide-polyethylene glycol-silane (mal-PEG-silane) to provide thiol reactive surface groups. The silanized, maleimide-bearing UCNPs were effective for conjugating to reductively-cleaved half antibodies against ofloxacin, a veterinary antibiotic, to produce photoluminescent nanobiosensors for its detection and quantification. The speed and minimum detection concentration (~10 nM) that we report for a competitive assay of ofloxacin in this study is promising for developing sensors for this and other biomolecules.

Misconceiving patient reported outcome measures (PROMs) as primarily a reporting requirement rather than a quality improvement tool: perceptions of independent healthcare sector stakeholders in the UK.

BACKGROUND: The independent healthcare sector in the UK collects PROMs for several surgical procedures, but implementation has been challenging. We aimed to understand the enablers and barriers to PROMs implementation in the independent healthcare sector in the UK. METHOD: Between January and May 2021, we remotely conducted semi-structured interviews with hospital consultants, hospital managers and other clinical staff using a topic guide developed from an implementation science framework called the Theoretical Domains Framework (TDF). RESULTS: We interviewed 6 hospital consultants, 5 hospital managers, and 3 other clinical staff (1 nurse and 2 physiotherapists) across 8 hospitals. Common barriers included: the perception that PROMs are predominantly a reporting requirement rather than a quality improvement tool, absence of feedback mechanisms for PROMs data for clinicians, poor awareness of PROMs among healthcare professionals and the public, absence of direction or commitment from leadership, and limited support from hospital consultants. Common enablers included: regular feedback of PROMs data to clinicians, designating roles and responsibilities, formally embedding PROMs collection into patient pathways, and involvement of hospital consultants in developing strategies to improve PROMs uptake. CONCLUSION: To support PROMs implementation, independent hospitals need to develop long-term organisational strategies that involve sustained leadership commitment, goals or targets, training opportunities to staff, and regular feedback of PROMs data at clinical or governance meetings. The primary purpose of PROMs needs to be reframed to independent healthcare sector stakeholders as a quality improvement tool rather than a reporting requirement.

Affimer Tagged Cubosomes: Targeting of Carcinoembryonic Antigen Expressing Colorectal Cancer Cells Using In Vitro and In Vivo Models.

Nanomedicines, while having been approved for cancer therapy, present many challenges such as low stability, rapid clearance, and nonspecificity leading to off-target toxicity. Cubosomes are porous lyotropic liquid crystalline nanoparticles that have shown great premise as drug delivery vehicles; however, their behavior in vivo is largely underexplored, hindering clinical translation. Here, we have engineered cubosomes based on the space group Im3m that are loaded with copper acetylacetonate as a model drug, and their surfaces are functionalized for the first time with Affimer proteins via copper-free click chemistry to actively target overexpressed carcinoembryonic antigens on LS174T colorectal cancer cells. Unlike nontargeted cubosomes, Affimer tagged cubosomes showed preferential accumulation in cancer cells compared to normal cells not only in vitro (2D monolayer cell culture and 3D spheroid models) but also in vivo in colorectal cancer mouse xenografts, while exhibiting low nonspecific absorption and toxicity in other vital organs. Cancerous spheroids had maximum cell death compared to noncancerous cells upon targeted delivery. Xenografts subjected to targeted drug-loaded cubosomes showed a 5-7-fold higher drug accumulation in the tumor tissue compared to the liver, kidneys, and other vital organs, a significant decrease in tumor growth, and an increased survival rate compared to the nontargeted group. This work encompasses the first thorough preclinical investigation of Affimer targeted cubosomes as a cancer therapeutic.

Fabrication and activity of silicate nanoparticles and nanosilicate-entrapped enzymes using polyethyleneimine as a biomimetic polymer.

In nature, some peptides induce precipitation of silicic acid into silica nanoparticles such as is found in marine algae called diatoms. However, polybasic polymers can act as peptide mimics; one such polymer, polyethyleneimine (PEI), has the advantage that it is stable at room temperature and is inexpensive, in comparison with synthetic peptides. We describe the fabrication and characterization of biosilicate nanoparticles formed by mimicking the peptides using PEI. Brownian motion nanoparticle tracking analysis and field emission gun scanning electron microscopy have been used for the first time to characterize nanoparticles made with tetramethyl orthosilicate (TMOS) and PEI to investigate the fundamental factors that affect particle properties. These factors include the effect of phosphate concentration, PEI molecular weight, TMOS concentration, and species of alkoxy-silane used. The properties of the particles are compared with other particles made with polymers that induce silication. Our results show that using PEI gives differences in particle size compared with previous work using other polymers that induce silication. The entrapment of enzymes during the silication process, rationale for using nonphosphate and phosphate buffers during enzyme entrapment, and the analysis of enzyme activity are also presented. Because enzymes can be entrapped during fabrication, it means that there are many future possibilities for the use of silicate nanoparticles containing enzymes, such as biosensors and biocatalytic reactors.

Selection and characterisation of Affimers specific for CEA recognition.

Carcinoembryonic antigen (CEA) is the only blood based protein biomarker at present, used for preoperative screening of advanced colorectal cancer (CRC) patients to determine the appropriate curative treatments and post-surveillance screening for tumour recurrence. Current diagnostics for CRC detection have several limitations and development of a highly sensitive, specific and rapid diagnostic device is required. The majority of such devices developed to date are antibody-based and suffer from shortcomings including multimeric binding, cost and difficulties in mass production. To circumvent antibody-derived limitations, the present study focused on the development of Affimer proteins as a novel alternative binding reagent for CEA detection. Here, we describe the selection, from a phage display library, of Affimers specific to CEA protein. Characterization of three anti-CEA Affimers reveal that these bind specifically and selectively to protein epitopes of CEA from cell culture lysate and on fixed cells. Kinetic binding analysis by SPR show that the Affimers bind to CEA with high affinity and within the nM range. Therefore, they have substantial potential for used as novel affinity reagents in diagnostic imaging, targeted CRC therapy, affinity purification and biosensor applications.

The Trimeric Autotransporter Adhesin YadA of Yersinia enterocolitica Serotype O:9 Binds Glycan Moieties.

Yersinia adhesin A (YadA) is a key virulence factor of Yersinia enterocolitica and Yersinia pseudotuberculosis. YadA is a trimeric autotransporter adhesin, a class of adhesins that have been shown to enable many Gram-negative pathogens to adhere to/interact with the host extracellular matrix proteins such as collagen, vitronectin, and fibronectin. Here, we show for the first time that YadA of Yersinia enterocolitica serotype O:9 not only interacts with proteinaceous surface molecules but can also attach directly to glycan moieties. We show that YadA from Y. enterocolitica serotype O:9 does not interact with the vitronectin protein itself but exclusively with its N-linked glycans. We also show that YadA can target other glycan moieties as found in heparin, for example. So far, little is known about specific interactions between bacterial autotransporter adhesins and glycans. This could potentially lead to new antimicrobial treatment strategies, as well as diagnostic applications.

Rasburicase-Induced Methemoglobinemia.

Methemoglobinemia occurs as iron in heme is oxidized to its ferric state, resulting in a decreased ability of hemoglobin to bind and release oxygen. Rasburicase is a recombinant urate-oxidase enzyme used in the prevention of tumor lysis syndrome. Methemoglobinemia can occur as a rare complication of treatment with rasburicase, primarily in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Methylene blue, an agent used for treating methemoglobinemia, should be avoided in patients with G6PD deficiency. In patients with G6PD deficiency, methylene blue is inadequately reduced to its active form, which then causes the methylene blue to further the oxidize the hemoglobin to methemoglobin that can result in hemolysis.

Reagentless Affimer- and antibody-based impedimetric biosensors for CEA-detection using a novel non-conducting polymer.

Polyoctopamine (POct), an amine-functionalised non-conducting polymer, as the transducer layer in an electrochemical biosensor, is presented. This polymer offers versatile covalent coupling either through thiol linker conjugation, carboxyl or aldehyde functional groups without the requirement of pre- or post-surface activation. The colorectal cancer biomarker carcinoembryonic antigen (CEA) was selected as the target analyte, whilst an antibody and a synthetic binding protein, an Affimer, were used as distinct bioreceptors to demonstrate the versatility of polyoctopamine as a transducer polymer layer for oriented immobilisation of the bioreceptors. The electrodeposited polymer layer was characterised using cyclic voltammetry, electrochemical impedance spectroscopy, and on-sensor chemiluminescent blotting. The performance of optimised POct-based biosensors were tested in spiked human serum. Results showed that the electropolymerisation of octopamine on screen printed gold electrode generates a thin polymer film with low resistance. Close proximity of the immobilised bioreceptors to the transducer layer greatly enhanced the sensitivity detection. The sensitivity of the smaller monomeric bioreceptor (Affimer, 12.6 kDa) to detect CEA was comparable to the dimeric antibody (150 kDa) with limit of detection at 11.76 fM which is significantly lower than the basal clinical levels of 25 pM. However, the Affimer-based sensor had a narrower dynamic range compared to the immunosensor (1-100 fM vs. 1 fM - 100 nM, respectively). All electrochemical measurements were done in less than 5 min with small sample volumes (10 µl). Hence, polyoctopamine features a simple fabrication of impedimetric biosensors using amine-functionalisation technique, provides rapid response time with enhanced sensitivity and label-free detection.