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Liposomes carrying chemotherapeutic drugs can accumulate passively in solid tumors at high levels. However, additional targeting of the liposomes towards e.g. receptors expressed on cancer cells may improve their interaction and therapeutic properties. In this study, we designed a liposomal delivery system, which utilizes the intrinsic characteristics of HER2-positive tumors to ensure efficient delivery of oxaliplatin to the cancer cells. On the liposome surface, trastuzumab, an antibody specific to the HER2 receptor, was shown to facilitate internalization by the cancer cells. A polyethylene glycol (PEG) layer on the liposome surface provides protection from mononuclear phagocyte system uptake. To optimize the interaction between liposomes and cancer cells, a protease-sensitive cleavable peptide linker was inserted at the base of each PEG. The PEG layer is then cleaved off by intra- and extracellular matrix metalloproteinases (MMPs) upon accumulation in the tumor. Our data demonstrate that the removal of PEG significantly destabilizes the liposomes and leads to substantial oxaliplatin release. The proposed beneficial effect of combining antibody-mediated internalization with MMP sensitivity was confirmed in a series of in vivo studies using ovarian cancer xenograft models. The results demonstrated that HER2-targeted MMP-sensitive liposomes have superior anticancer activity compared to non-targeted and non-cleavable liposomes.
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Antineoplásicos , Liposomas , Neoplasias Ováricas , Oxaliplatino , Polietilenglicoles , Receptor ErbB-2 , Trastuzumab , Femenino , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/patología , Animales , Humanos , Receptor ErbB-2/metabolismo , Receptor ErbB-2/inmunología , Oxaliplatino/administración & dosificación , Línea Celular Tumoral , Polietilenglicoles/química , Polietilenglicoles/administración & dosificación , Antineoplásicos/administración & dosificación , Antineoplásicos/uso terapéutico , Antineoplásicos/farmacología , Antineoplásicos/farmacocinética , Antineoplásicos/química , Trastuzumab/administración & dosificación , Trastuzumab/química , Ratones Desnudos , Sistemas de Liberación de Medicamentos , Compuestos Organoplatinos/administración & dosificación , Compuestos Organoplatinos/química , Compuestos Organoplatinos/farmacología , Ensayos Antitumor por Modelo de Xenoinjerto , Metaloproteinasas de la Matriz/metabolismo , Ratones , Ratones Endogámicos BALB CRESUMEN
BACKGROUND: Bone infections from Staphylococcus aureus are notoriously difficult to treat and have high recurrence rates. Local antibiotic delivery systems hold the potential to achieve high in situ antibiotic concentrations, which are otherwise challenging to achieve via systemic administration. Existing solutions have been shown to confer suboptimal drug release and distribution. Here we present and evaluate an injectable in situ-forming depot system termed CarboCell. The CarboCell technology provides sustained and tuneable release of local high-dose antibiotics. METHODS: CarboCell formulations of levofloxacin or clindamycin with or without antimicrobial adjuvants cis-2-decenoic acid or cis-11-methyl-2-dodecenoic acid were tested in experimental rodent and porcine implant-associated osteomyelitis models. In the porcine models, debridement and treatment with CarboCell-formulated antibiotics was carried out without systemic antibiotic administration. The bacterial burden was determined by quantitative bacteriology. RESULTS: CarboCell formulations eliminated S. aureus in infected implant rat models. In the translational implant-associated pig model, surgical debridement, and injection of clindamycin-releasing CarboCell formulations resulted in pathogen-free bone tissues and implants in 9/12, and full eradication in 5/12 pigs. CONCLUSIONS: Sustained release of antimicrobial agents mediated by the CarboCell technology demonstrated promising therapeutic efficacy in challenging translational models and may be beneficial in combination with the current standard of care.
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The oral bioavailability of therapeutic peptides is generally low. To increase peptide transport across the gastrointestinal barrier, permeation enhancers are often used. Despite their widespread use, mechanistic knowledge of permeation enhancers is limited. To address this, we here investigate the interactions of six commonly used permeation enhancers with lipid membranes in simulated intestinal environments. Specifically, we study the interactions of the permeation enhancers sodium caprate, dodecyl maltoside, sodium cholate, sodium dodecyl sulfate, melittin, and penetratin with epithelial cell-like model membranes. To mimic the molecular composition of the real intestinal environment, the experiments are performed with two peptide drugs, salmon calcitonin and desB30 insulin, in fasted-state simulated intestinal fluid. Besides providing a comparison of the membrane interactions of the studied permeation enhancers, our results demonstrate that peptide drugs as well as intestinal-fluid components may substantially change the membrane activity of permeation enhancers. This highlights the importance of testing permeation enhancement in realistic physiological environments and carefully choosing a permeation enhancer for each individual peptide drug.
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Absorción Intestinal , Mucosa Intestinal , Humanos , Mucosa Intestinal/metabolismo , Células CACO-2 , Absorción Intestinal/fisiología , Transporte Biológico , Lípidos , PermeabilidadRESUMEN
Purpose: Obesity may alter the severity of infection with Coronavirus disease 2019 (COVID-19). Age may impact the association between body weight and severity of COVID-19 in patients with obesity. The aim of the study was to examine the association between obesity and severity of infection in a Danish cohort hospitalized with COVID-19 in the initial wave of the pandemic. Patients and methods: Based on data from the nationwide, clinical database: COVID-DK, risks of intensive care unit (ICU) admission, invasive mechanical ventilation (IMV), and mortality were compared among patients with and without obesity. Interaction with age was examined and we used Inverse Probability of Treatment Weighting regression for confounder adjustment. Results: Among 524 patients, 142 (27%) were admitted to the ICU, 112 (21%) required IMV, and 109 (21%) died. Compared to COVID-19 patients without obesity, patients with obesity displayed a non-significant increased risk of ICU admission (Relative Risk [RR] 1.19, 95% Confidence Interval [CI] 0.88; 1.60), IMV (RR 1.23, CI 0.86; 1.75) and mortality (RR 1.21, CI 0.84; 1.75). COVID-19 patients with obesity, <60 years had highly increased risk of ICU admission (RR 1.92, CI 1.14; 3.24) and IMV (RR 1.95, CI 1.09; 3.49). Conclusions: In hospitalized COVID-19 patients, obesity conferred an approximately 20% increased risk for ICU admission, IMV, and death, although these relationships did not reach statistical significance. COVID-19 patients with obesity and <60 years had an almost doubled risk of ICU admission and IMV.
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Purpose: Drug delivery to the retina remains a challenge due to ocular barriers and fast clearing mechanisms. Nanocarrier drug delivery systems (NDDSs) hold the promise of prolonging intraocular retention times and increasing drug concentrations in the retina. Methods: Anionic and cationic PEGylated liposomes, loaded with oxaliplatin (OxPt) to be used as trace element, were prepared from dry lipid powders. The differently charged liposomes were intravitreally injected in C57BL/6JrJ mice; eyes were harvested 2 hours and 24 hours post-injection. To investigate active transport mechanisms in the eye, a subset of mice were pre-injected with chloroquine before injection with cationic liposomes. Eyes were dissected and the distribution of OxPt in different tissues were quantified by inductively coupled plasma mass spectrometry (ICP-MS). Results: Both liposome formulations enhanced the retention time of OxPt in the vitreous over free OxPt. Surprisingly, when formulated in cationic liposomes, OxPt translocated through the retina and accumulated in the RPE-sclera. Pre-injection with chloroquine inhibited the transport of liposomal OxPt from the vitreous to the RPE-sclera. Conclusions: We show that liposomes can enhance the retention time of small molecular drugs in the vitreous and that active transport mechanisms are involved in the trans retinal transport of NDDS after intravitreal injections. Translational Relevance: These results highlight the need for understanding the dynamics of ocular transport mechanisms in living eyes when designing NDDS with the back of the eye as the target. Active transport of nanocarriers through the retina will limit the drug concentration in the neuronal retina but might be exploited for targeting the RPE.
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Liposomas , Retina , Animales , Ratones , Ratones Endogámicos C57BL , Esclerótica , Cloroquina , OxaliplatinoRESUMEN
Changes in the T cell receptor (TCR) repertoires have become important markers for monitoring disease or therapy progression. With the rise of immunotherapy usage in cancer, infectious and autoimmune disease, accurate assessment and comparison of the "state" of the TCR repertoire has become paramount. One important driver of change within the repertoire is T cell proliferation following immunisation. A way of monitoring this is by investigating large clones of individual T cells believed to bind epitopes connected to the disease. However, as a single target can be bound by many different TCRs, monitoring individual clones cannot fully account for T cell cross-reactivity. Moreover, T cells responding to the same target often exhibit higher sequence similarity, which highlights the importance of accounting for TCR similarity within the repertoire. This complexity of binding relationships between a TCR and its target convolutes comparison of immune responses between individuals or comparisons of TCR repertoires at different timepoints. Here we propose TCRDivER algorithm (T cell Receptor Diversity Estimates for Repertoires), a global method of T cell repertoire comparison using diversity profiles sensitive to both clone size and sequence similarity. This approach allowed for distinction between spleen TCR repertoires of immunised and non-immunised mice, showing the need for including both facets of repertoire changes simultaneously. The analysis revealed biologically interpretable relationships between sequence similarity and clonality. These aid in understanding differences and separation of repertoires stemming from different biological context. With the rise of availability of sequencing data we expect our tool to find broad usage in clinical and research applications.
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Receptores de Antígenos de Linfocitos T , Linfocitos T , Ratones , Animales , Receptores de Antígenos de Linfocitos T/metabolismo , Inmunización , Inmunoterapia , AlgoritmosRESUMEN
Oral drug delivery increases patient compliance and is thus the preferred administration route for most drugs. However, for biologics the intestinal barrier greatly limits the absorption and reduces their bioavailability. One strategy employed to improve on this is chemical modification of the biologic through the addition of lipid side chains. While it has been established that lipidation of peptides can increase transport, a mechanistic understanding of this effect remains largely unexplored. To pursue this mechanistic understanding, end-point detection of biopharmaceuticals transported through a monolayer of fully polarized epithelial cells is typically used. However, these methods are time-consuming and tedious. Furthermore, most established methods cannot be combined easily with high-resolution live-cell fluorescence imaging that could provide a mechanistic insight into cellular uptake and transport. Here we address this challenge by developing an axial PSF deconvolution scheme to quantify the transport of peptides through a monolayer of Caco-2 cells using single-cell analysis with live-cell confocal fluorescence microscopy. We then measure the known cross-barrier transport of several compounds in our model and compare the results with results obtained in an established microfluidic model finding similar transport phenotypes. This verifies that already after two days the Caco-2 cells in our model form a tight monolayer and constitute a functional barrier model. We then apply this assay to investigate the effects of side chain lipidation of the model peptide drug salmon calcitonin (sCT) modified with 4carbon and 8carbon-long fatty acid chains. Furthermore, we compare that with experiments performed at lower temperature and using inhibitors for some endocytotic pathways to pinpoint how lipidation length modifies the main avenues for the transport. We thus show that increasing the length of the lipid chain increases the transport of the drug significantly but also makes endocytosis the primary transport mechanism in a short-term cell culture model.
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Células Epiteliales , Péptidos , Humanos , Células CACO-2 , Transporte Biológico , Células Epiteliales/metabolismo , Péptidos/farmacología , Ácidos Grasos/metabolismo , Absorción Intestinal , Mucosa Intestinal/metabolismoRESUMEN
The growing interest in biopharmaceuticals combined with the challenges regarding formulation and delivery continues to encourage the development of new and improved formulations of this class of therapeutics. Nanoclusters (NCs) represent a type of formulation strategy where the biopharmaceutical is clustered in a reversible manner to function as both the therapeutic and the vehicle. In this study, insulin NCs (INCs) were formulated by a new methodology of first crosslinking proteins followed by desolvation. Crosslinking of the protein with the reducible DTSSP crosslinker improved control of the INC synthesis process to give INCs with a mean size of 198 ± 7 nm and a mean zeta potential of -39 ± 1 mV. Crosslinking and clustering of insulin did not induce cytotoxicity or major differences in the biological activity compared to the free unmodified protein. The potency of the crosslinked insulin and the INCs appeared slightly lower than that of the unmodified protein, and significantly higher doses of the INCs compared to the free protein were applied to achieve similar blood sugar lowering effects in vivo. Interestingly, the INCs allowed for high doses to be subcutaneously delivered with prolonged efficacy without being lethal in rats.
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Insulina , Proteínas , Ratas , Animales , Preparaciones de Acción Retardada/farmacología , ExcipientesRESUMEN
Despite being an indispensable clinical procedure, the transfusion of donor blood has important limitations including a short shelf-life, limited availability and specific storage requirements. Therefore, a lot of effort has been devoted to developing hemoglobin (Hb)-based oxygen carriers (HBOCs) that are able to replace or complement standard blood transfusions, especially in extreme life-threatening situations. Herein, we employed a Hb-loaded poly(lactide-co-glycolide) core which was subsequently coated with nanozymes to protect the encapsulated Hb from oxidation by reactive oxygen species. To render HBOCs with long circulation in the vasculature, which is a crucial requirement to achieve the high oxygen demands of our organism, the carrier was coated with a red blood cell-derived membrane. Three coating methods were explored and evaluated by their ability to repel the deposition of proteins and minimize their uptake by an endothelial cell line. Preservation of the oxygen carrying capacity of the membrane-coated carrier was demonstrated by an oxygen-binding and releasing assay and, the functionality resulting from the entrapped nanozymes, was shown by means of superoxide radical anion and hydrogen peroxide depletion assays. All in all, we have demonstrated the potential of the membrane-coated nanocarriers as novel oxygen carrying systems with both antioxidant and stealth properties.
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Sustitutos Sanguíneos , Sustitutos Sanguíneos/química , Recuento de Eritrocitos , Eritrocitos/metabolismo , Hemoglobinas/química , Oxígeno/químicaRESUMEN
Quantification of cytokines in cancerous tissue is important for understanding basic tumor biology and for deciphering anti-cancer mechanisms in drug development. Cytokine measurements on protein-level are often done by immunoassays such as enzyme-linked immunosorbent assay (ELISAs) and multiplex assays. However, immunoassays are prone to interference due to the presence of perturbing factors. The sum of these factors is known as the matrix effect, which results in a deviation of the measured cytokine concentration from the actual concentration. In this study, we demonstrated that matrix effects are present in tumor lysates from 11 different syngeneic murine tumors and that it can greatly affect cytokine measurements in ELISAs and multiplex assays. Dilution of tumor lysates and careful selection of lysis buffer components may decrease matrix effects. However, matrix effects are still present, and care should be taken when analyzing cytokine measurements of tumor lysates.
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Citocinas/metabolismo , Ensayo de Inmunoadsorción Enzimática/métodos , Neoplasias/metabolismo , Animales , Línea Celular Tumoral , Errores Diagnósticos , Femenino , Ratones , Ratones Endogámicos BALB C , Microambiente TumoralRESUMEN
The efficacy of anti-programmedcelldeath1therapy (aPD-1), which was recently approved for basal cell carcinoma (BCC) treatment, can be enhanced by adjuvant ablative fractional laser (AFL) in syngeneic murine tumor models. In this explorative study, we aimed to assess locally applied AFL as an adjuvant to systemic aPD-1 treatment in a clinically relevant autochthonous BCC model. BCC tumors (n = 72) were induced in Ptch1+/-K14-CreER2p53fl/fl-mice (n = 34), and the mice subsequently received aPD-1 alone, AFL alone, aPD-1+AFL, or no treatment. The outcome measures included mouse survival time, tumor clearance, tumor growth rates, and tumor immune infiltration. Both aPD-1 and AFL alone significantly increased survival time relative to untreated controls (31 d and 34.5 d, respectively vs. 14 d, p = 0.0348-0.0392). Complementing aPD-1 with AFL further promoted survival (60 d, p = 0.0198 vs. aPD-1) and improved tumor clearance and growth rates. The BCCs were poorly immune infiltrated, but aPD-1 with adjuvant AFL and AFL alone induced substantial immune cell infiltration in the tumors. Similar to AFL alone, combined aPD-1 and AFL increased neutrophil counts (4-fold, p = 0.0242), the proportion of MHCII-positive neutrophils (p = 0.0121), and concordantly, CD4+ and CD8+ T-cell infiltration (p = 0.0061-0.0242). These descriptive results suggest that the anti-tumor response that is generated by aPD-1 with adjuvant AFL is potentially promoted by increased neutrophil and T-cell engraftment in tumors. In conclusion, local AFL shows substantial promise as an adjuvant to systemic aPD-1 therapy in a clinically relevant preclinical BCC model.
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Surgery is still the first-line treatment for multiple solid cancers. However, recurrence is a common issue, especially when dealing with aggressive tumors or tumors that are difficult to completely remove due to their location. Getting clear surgical margins can be challenging, but treatment strategies combining surgery with other anti-cancer therapies can potentially improve the outcome. Photothermal therapy (PTT) is a technique that relies on photoabsorbing agents, such as gold nanoparticles, to transform light into local hyperthermia. This technique can be used to ablate tumor tissue where the photoabsorbing agent accumulates, sparing healthy surrounding tissue. In this study, we examined the potential of gold nanoparticle-based PTT as an adjuvant treatment to surgery in a mouse model of human fibrosarcoma. For this we performed subtotal tumor resection to mimic a clinical situation where total tumor removal is not achieved, and subsequent PTT was applied on the surgical field. Our results showed that animals undergoing adjuvant PTT after surgery presented sustained delayed tumor growth and improved survival when compared to animals that only underwent surgery. We believe that these findings show the potential of PTT as an adjuvant method to traditional tumor surgery and could pave way to more personalized treatment options.
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The current nucleic acid signal amplification methods for SARS-CoV-2 RNA detection heavily rely on the functions of biological enzymes which imposes stringent transportation and storage conditions, high cost and global supply shortages. Here, a non-enzymatic whole genome detection method based on a simple isothermal signal amplification approach is developed for rapid detection of SARS-CoV-2 RNA and potentially any types of nucleic acids regardless of their size. The assay, termed non-enzymatic isothermal strand displacement and amplification (NISDA), is able to quantify 10 RNA copies.µL-1. In 164 clinical oropharyngeal RNA samples, NISDA assay is 100 % specific, and it is 96.77% and 100% sensitive when setting up in the laboratory and hospital, respectively. The NISDA assay does not require RNA reverse-transcription step and is fast (<30 min), affordable, highly robust at room temperature (>1 month), isothermal (42 °C) and user-friendly, making it an excellent assay for broad-based testing.
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Prueba de Ácido Nucleico para COVID-19/métodos , COVID-19/diagnóstico , Técnicas de Amplificación de Ácido Nucleico/métodos , ARN Viral/aislamiento & purificación , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificación , COVID-19/virología , Prueba de COVID-19 , Humanos , ARN Viral/genética , Recombinación GenéticaRESUMEN
Oral delivery is a highly preferred method for drug administration due to high patient compliance. However, oral administration is intrinsically challenging for pharmacologically interesting drug classes, in particular pharmaceutical peptides, due to the biological barriers associated with the gastrointestinal tract. In this review, we start by summarizing the pharmacological performance of several clinically relevant orally administrated therapeutic peptides, highlighting their low bioavailabilities. Thus, there is a strong need to increase the transport of peptide drugs across the intestinal barrier to realize future treatment needs and further development in the field. Currently, progress is hampered by a lack of understanding of transport mechanisms that govern intestinal absorption and transport of peptide drugs, including the effects of the permeability enhancers commonly used to mediate uptake. We describe how, for the past decades, mechanistic insights have predominantly been gained using functional assays with end-point read-out capabilities, which only allow indirect study of peptide transport mechanisms. We then focus on fluorescence imaging that, on the other hand, provides opportunities to directly visualize and thus follow peptide transport at high spatiotemporal resolution. Consequently, it may provide new and detailed mechanistic understanding of the interplay between the physicochemical properties of peptides and cellular processes; an interplay that determines the efficiency of transport. We review current methodology and state of the art in the field of fluorescence imaging to study intestinal barrier transport of peptides, and provide a comprehensive overview of the imaging-compatible in vitro, ex vivo, and in vivo platforms that currently are being developed to accelerate this emerging field of research.
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Effective treatments of neurodegenerative diseases require drugs to be actively transported across the blood-brain barrier (BBB). However, nanoparticle drug carriers explored for this purpose show negligible brain uptake, and the lack of basic understanding of nanoparticle-BBB interactions underlies many translational failures. Here, using two-photon microscopy in mice, we characterize the receptor-mediated transcytosis of nanoparticles at all steps of delivery to the brain in vivo. We show that transferrin receptor-targeted liposome nanoparticles are sequestered by the endothelium at capillaries and venules, but not at arterioles. The nanoparticles move unobstructed within endothelium, but transcytosis-mediated brain entry occurs mainly at post-capillary venules, and is negligible in capillaries. The vascular location of nanoparticle brain entry corresponds to the presence of perivascular space, which facilitates nanoparticle movement after transcytosis. Thus, post-capillary venules are the point-of-least resistance at the BBB, and compared to capillaries, provide a more feasible route for nanoparticle drug carriers into the brain.
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Encéfalo/metabolismo , Capilares/metabolismo , Portadores de Fármacos , Nanopartículas/uso terapéutico , Transcitosis/fisiología , Vénulas/metabolismo , Animales , Arteriolas , Transporte Biológico , Barrera Hematoencefálica , Capilares/patología , Endotelio/diagnóstico por imagen , Endotelio/patología , Cinética , Liposomas/metabolismo , Ratones , Receptores de Transferrina/metabolismo , Vénulas/patologíaRESUMEN
Diabetes is a serious chronic disease, which globally affects more than 400 million patients. Beta cell therapy has potential to serve as an effective cure to type 1 diabetes and several studies have already shown promising results in this regard. One of the major obstacles in cell therapy, however, is the hypoxic environment that therapeutic cells are subjected to immediately after the transplantation. In this study, a new approach is presented, based on hydrogels composed of thiolated hyaluronic acid (tHA), 8-arm-Poly(ethylene glycol)-Acrylate (PEGA), and calcium peroxide (CPO) as an oxygen releasing system. Hydrogels containing 0, 7.5, and 30% CPO were prepared, and the presence of CPO was confirmed via FTIR and Alizarin Red within the network. Oxygen release kinetics were monitored over time, and the results revealed that the hydrogels containing 30% CPO could release oxygen for at least 30 h. All three combinations were found to be injectable and suitable for beta cell therapy based on their mechanical and rheological properties. Additionally, to investigate the functionality of the system, insulin secreting INS-1E reporter cell clusters were encapsulated, and their viability was evaluated, which showed that CPO incorporation enhanced cell survival for at least three days.
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Hidrogeles , Células Secretoras de Insulina , Supervivencia Celular , Humanos , Oxígeno , PolietilenglicolesRESUMEN
The blood-brain barrier (BBB) is one of the main obstacles for therapies targeting brain diseases. Most macromolecules fail to pass the tight BBB, formed by brain endothelial cells interlinked by tight junctions. A wide range of small, lipid-soluble molecules can enter the brain parenchyma via diffusion, whereas macromolecules have to transcytose via vesicular transport. Vesicular transport can thus be utilized as a strategy to deliver brain therapies. By conjugating BBB targeting antibodies and peptides to therapeutic molecules or nanoparticles, it is possible to increase uptake into the brain. Previously, the synthetic peptide GYR and a peptide derived from melanotransferrin (MTfp) have been suggested as candidates for mediating transcytosis in brain endothelial cells (BECs). Here we study uptake, intracellular trafficking, and translocation of these two peptides in BECs. The peptides were synthesized, and binding studies to purified endocytic receptors were performed using surface plasmon resonance. Furthermore, the peptides were conjugated to a fluorophore allowing for live-cell imaging studies of their uptake into murine brain endothelial cells. Both peptides bound to low-density lipoprotein receptor-related protein 1 (LRP-1) and the human transferrin receptor, while lower affinity was observed against the murine transferrin receptor. The MTfp showed a higher binding affinity to all receptors when compared to the GYR peptide. The peptides were internalized by the bEnd.3 mouse endothelial cells within 30 min of incubation and frequently co-localized with endo-lysosomal vesicles. Moreover, our in vitro Transwell translocation experiments confirmed that GYR was able to cross the murine barrier and indicated the successful translocation of MTfp. Thus, despite binding to endocytic receptors with different affinities, both peptides are able to transcytose across the murine BECs.
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Barrera Hematoencefálica/efectos de los fármacos , Encéfalo/efectos de los fármacos , Sistemas de Liberación de Medicamentos/métodos , Células Endoteliales/efectos de los fármacos , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/antagonistas & inhibidores , Péptidos/farmacología , Receptores de Transferrina/antagonistas & inhibidores , Animales , Barrera Hematoencefálica/metabolismo , Encéfalo/metabolismo , Células Cultivadas , Células Endoteliales/metabolismo , Colorantes Fluorescentes/química , Colorantes Fluorescentes/farmacología , Humanos , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/metabolismo , Glicoproteínas de Membrana/metabolismo , Ratones , Receptores de Transferrina/metabolismo , TranscitosisRESUMEN
Control of the ongoing coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) will require one or more vaccines. Currently, numerous SARS-CoV-2 vaccines are in either pre-clinical or clinical development. Twenty are in fase III development. In this review we summarise available safety and efficacy data of two RNA based vaccines, two non-replication competent vector-based vaccine, one inactivated whole-virus vaccine, and one subunit. All being either approved or nearing approval.
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Vacunas contra la COVID-19/inmunología , COVID-19/prevención & control , Pandemias/prevención & control , SARS-CoV-2 , COVID-19/epidemiología , Vacunas contra la COVID-19/efectos adversos , HumanosRESUMEN
The blood-brain barrier (BBB) is a major obstacle to treating several brain disorders. Focused ultrasound (FUS) in combination with intravascular microbubbles increases BBB permeability by opening tight junctions, creating endothelial cell openings, improving endocytosis and increasing transcytosis. Here we investigated whether combining FUS and microbubbles with transferrin receptor-targeting liposomes would result in enhanced delivery to the brain of post-natal rats compared with liposomes lacking the BBB-targeting moiety. For all animals, increased BBB permeability was observed after FUS treatment. A 40% increase in accumulation of transferrin receptor-targeting liposomes was observed in the FUS-treated hemisphere, whereas the isotype immunoglobulin G liposomes showed no increased accumulation. Confocal laser scanning microscopy of brain sections revealed that both types of liposomes were mainly observed in endothelial cells in the FUS-treated hemisphere. The results demonstrate that FUS and microbubble treatment combined with BBB-targeting liposomes could be a promising approach to enhance drug delivery to the brain.
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Barrera Hematoencefálica/efectos de la radiación , Sistemas de Liberación de Medicamentos/métodos , Liposomas , Microburbujas , Receptores de Transferrina , Ondas Ultrasónicas , Animales , Permeabilidad/efectos de la radiación , Ratas , Ratas Sprague-DawleyRESUMEN
Gautret and colleagues reported the results of a non-randomised case series which examined the effects of hydroxychloroquine and azithromycin on viral load in the upper respiratory tract of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients. The authors reported that hydroxychloroquine (HCQ) had significant virus reducing effects, and that dual treatment of both HCQ and azithromycin further enhanced virus reduction. In light of criticisms regarding how patients were excluded from analyses, we reanalysed the original data to interrogate the main claims of the paper. We applied Bayesian statistics to assess the robustness of the original paper's claims by testing four variants of the data: 1) The original data; 2) Data including patients who deteriorated; 3) Data including patients who deteriorated with exclusion of untested patients in the comparison group; 4) Data that includes patients who deteriorated with the assumption that untested patients were negative. To ask if HCQ monotherapy was effective, we performed an A/B test for a model which assumes a positive effect, compared to a model of no effect. We found that the statistical evidence was highly sensitive to these data variants. Statistical evidence for the positive effect model ranged from strong for the original data (BF+0 ~11), to moderate when including patients who deteriorated (BF+0 ~4.35), to anecdotal when excluding untested patients (BF+0 ~2), and to anecdotal negative evidence if untested patients were assumed positive (BF+0 ~0.6). The fact that the patient inclusions and exclusions are not well justified nor adequately reported raises substantial uncertainty about the interpretation of the evidence obtained from the original paper.