Antioxidant activity of the main phenolics found in red fruits: An in vitro and in silico study.

The current study analysed the antioxidant capacity of the main phenolics found in red fruits. In total, there were analysed the antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl radical, nitric oxide and superoxide radicals (DPPH, NO and O2-, respectively) of 23 phenolics. Regarding DPPH, anthocyanins, (-)-epicatechin and kaempferol 3-O-rutinoside were the most active, while isorhamnetin 3-O-glucoside was the least active. Anthocyanins, (-)-epicatechin, quercetin 3-O-glucoside and caffeic acid showed the strongest potential against NO, while ρ-hydroxybenzoic acid was the less efficient. Regarding the O2- assay, quercetin aglycone and their derivatives were the best ones, while cyanidin aglycone did not show any potential to quench this radical. To deeper explore the biological potential of the most promising compounds, docking molecular and ADME studies were also done. The obtained data is another support regarding the biological potential of phenolics and might be useful in encouraging their use and incorporation in new products.

Krüppel-like factors: potential roles in blood-brain barrier dysfunction and epileptogenesis.

Epilepsy is a chronic and debilitating neurological disorder, known for the occurrence of spontaneous and recurrent seizures. Despite the availability of antiseizure drugs, 30% of people with epilepsy experience uncontrolled seizures and drug resistance, evidencing that new therapeutic options are required. The process of epileptogenesis involves the development and expansion of tissue capable of generating spontaneous recurrent seizures, during which numerous events take place, namely blood-brain barrier (BBB) dysfunction, and neuroinflammation. The consequent cerebrovascular dysfunction results in a lower seizure threshold, seizure recurrence, and chronic epilepsy. This suggests that improving cerebrovascular health may interrupt the pathological cycle responsible for disease development and progression. Krüppel-like factors (KLFs) are a family of zinc-finger transcription factors, encountered in brain endothelial cells, glial cells, and neurons. KLFs are known to regulate vascular function and changes in their expression are associated with neuroinflammation and human diseases, including epilepsy. Hence, KLFs have demonstrated various roles in cerebrovascular dysfunction and epileptogenesis. This review critically discusses the purpose of KLFs in epileptogenic mechanisms and BBB dysfunction, as well as the potential of their pharmacological modulation as therapeutic approach for epilepsy treatment.

Intranasal delivery of paroxetine: A preclinical study on pharmacokinetics, depressive-like behaviour, and neurochemical sex differences.

Treatment of major depressive disorder remains a major unmet clinical need. Given the advantages of intranasal administration for targeted brain delivery, the present study aimed at investigating the pharmacokinetics of paroxetine, after its intranasal instillation and assessing its potential therapeutic effect on female and male mice subjected to unpredictable chronic mild stress (UCMS) protocol. IN administration revealed direct nose-to-brain paroxetine delivery but dose- and sex-dependent differences. Pharmacokinetics was nonlinear and paroxetine concentrations were consistently higher in plasma and brain of male mice. Additionally, UCMS decreased animal preference for sucrose in both male and female mice following acute (p < 0.01) and chronic stress (p < 0.05), suggesting anhedonia. Both male and female mice exhibited depressive-like behavior in the forced swimming test. UCMS females displayed a significantly longer immobility time and shorter climbing time than the control group (p < 0.05), while no differences were found between male mice. Two weeks of paroxetine intranasal administration reduced immobility time and lengthened climbing and swimming time, approaching values similar to those observed in the healthy control group. The therapeutic effect was stronger on female mice. Importantly, melatonin plasma levels were significantly decreased in female mice following UCMS (p < 0.05), while males exhibited heightened corticosterone levels. On the other hand, treatment with IN paroxetine significantly increased corticosterone and melatonin levels in both sexes compared to healthy mice (p < 0.05). Intranasal paroxetine delivery undoubtedly ameliorated the behavioral despair, characteristic of depressive-like animals. Despite its efficiency in male and female mice subjected to UCMS, females were more prone to this novel therapeutic strategy.

A physiological approach to renal clearance: From premature neonates to adults.

AIMS: We propose using glomerular filtration rate (GFR) as the physiological basis for distinguishing components of renal clearance. METHODS: Gentamicin, amikacin and vancomycin are thought to be predominantly excreted by the kidneys. A mixed-effects joint model of the pharmacokinetics of these drugs was developed, with a wide dispersion of weight, age and serum creatinine. A dataset created from 18 sources resulted in 27,338 drug concentrations from 9,901 patients. Body size and composition, maturation and renal function were used to describe differences in drug clearance and volume of distribution. RESULTS: This study demonstrates that GFR is a predictor of two distinct components of renal elimination clearance: (1) GFR clearance associated with normal GFR and (2) non-GFR clearance not associated with normal GFR. All three drugs had GFR clearance estimated as a drug-specific percentage of normal GFR (gentamicin 39%, amikacin 90% and vancomycin 57%). The total clearance (sum of GFR and non-GFR clearance), standardized to 70 kg total body mass, 176 cm, male, renal function 1, was 5.58 L/h (95% confidence interval [CI] 5.50-5.69) (gentamicin), 7.77 L/h (95% CI 7.26-8.19) (amikacin) and 4.70 L/h (95% CI 4.61-4.80) (vancomycin). CONCLUSIONS: GFR provides a physiological basis for renal drug elimination. It has been used to distinguish two elimination components. This physiological approach has been applied to describe clearance and volume of distribution from premature neonates to elderly adults with a wide dispersion of size, body composition and renal function. Dose individualization has been implemented using target concentration intervention.

Intranasal administration of sertraline ensures sustained brain delivery and antidepressant effect in a mouse model of depression.

The pursuit of more potent and efficacious antidepressant therapies is of utmost significance. Herein, the intranasal (IN) route was investigated for sertraline brain delivery, encompassing a comparative pharmacokinetic study after a single-dose administration to mice by IN, intravenous (IV) (4.87 mg/kg) and oral (10 mg/kg) routes, and an efficacy/toxicity study to explore the therapeutic effect in mice subjected to the unpredictable chronic mild stress (UCMS) protocol. Neurotransmitters and melatonin were quantified in prefrontal cortex and plasma, respectively. A different drug biodistribution behavior was unveiled for a CNS-acting drug administered by means of the IN route. For the first time, IN administration of sertraline exhibited heightened systemic exposure (bioavailability = 166 %), and a sustained drug release into the brain, in opposition to IV and oral routes, avoiding drug fluctuation. The lower lung exposition (given by normalized area under the curve) observed after IN instillation envisions the reduction of sertraline pulmonary side effects and similarly other peripheral side effects. IN sertraline treatment displayed significant efficacy in ameliorating anhedonia after one week of administration while the 14-day IN treatment regimen translated into decreased immobility time and increased swimming time in the forced swimming test, suggesting an improvement of the depressive-like behavior displayed by the animal depressive-model. Remarkably, these effects were absent with oral sertraline, despite the higher used dose. Noteworthy neurotransmitter alterations were observed, with IN sertraline markedly reducing adrenaline in the prefrontal cortex, while serotonin and melatonin increased following both administration routes. With its sustained brain delivery and serotonin- and melatonin-enhancing potential, the innovative strategy of IN sertraline holds the potential not only to effectively address depressive symptoms but also to mitigate challenges inherent to classic treatments.

Diversity of Culture Microorganisms from Portuguese Sweet Cherries.

Consumers today seek safe functional foods with proven health-promoting properties. Current evidence shows that a healthy diet can effectively alleviate oxidative stress levels and reduce inflammatory markers, thereby preventing the occurrence of many types of cancer, hypertension, and cardiovascular and neurological pathologies. Nevertheless, as fruits and vegetables are mainly consumed fresh, they can serve as vectors for the transmission of pathogenic microorganisms associated with various disease outbreaks. As a result, there has been a surge in interest in the microbiome of fruits and vegetables. Therefore, given the growing interest in sweet cherries, and since their microbial communities have been largely ignored, the primary purpose of this study is to investigate their culturome at various maturity stages for the first time. A total of 55 microorganisms were isolated from sweet cherry fruit, comprising 23 bacteria and 32 fungi species. Subsequently, the selected isolates were molecularly identified by amplifying the 16S rRNA gene and ITS region. Furthermore, it was observed that the communities became more diverse as the fruit matured. The most abundant taxa included Pseudomonas and Ralstonia among the bacteria, and Metschnikowia, Aureobasidium, and Hanseniaspora among the fungi.

Under the umbrella of depression and Alzheimer's disease physiopathology: Can cannabinoids be a dual-pleiotropic therapy?

Depression and Alzheimer´s disease (AD) are two disorders highly prevalent worldwide. Depression affects more than 300 million people worldwide while AD affects 60-80% of the 55 million cases of dementia. Both diseases are affected by aging with high prevalence in elderly and share not only the main brain affected areas but also several physiopathological mechanisms. Depression disease is already ascribed as a risk factor to the development of AD. Despite the wide diversity of pharmacological treatments currently available in clinical practice for depression management, they remain associated to a slow recovery process and to treatment-resistant depression. On the other hand, AD treatment is essentially based in symptomatology relieve. Thus, the need for new multi-target treatments arises. Herein, we discuss the current state-of-art regarding the contribution of the endocannabinoid system (ECS) in synaptic transmission processes, synapses plasticity and neurogenesis and consequently the use of exogenous cannabinoids in the treatment of depression and on delaying the progression of AD. Besides the well-known imbalance of neurotransmitter levels, including serotonin, noradrenaline, dopamine and glutamate, recent scientific evidence highlights aberrant spine density, neuroinflammation, dysregulation of neurotrophic factor levels and formation of amyloid beta (Aß) peptides, as the main physiopathological mechanisms compromised in depression and AD. The contribution of the ECS in these mechanisms is herein specified as well as the pleiotropic effects of phytocannabinoids. At the end, it became evident that Cannabinol, Cannabidiol, Cannabigerol, Cannabidivarin and Cannabichromene may act in novel therapeutic targets, presenting high potential in the pharmacotherapy of both diseases.

Artificial Dendritic Cells: A New Era of Promising Antitumor Immunotherapy.

The accelerated development of antitumor immunotherapies in recent years has brought immunomodulation into the spotlight. These include immunotherapeutic treatments with dendritic cell (DC)-based vaccines which can elicit tumor-specific immune responses and prolong survival. However, this personalized treatment has several drawbacks, including being costly, labor-intensive, and time consuming. This has sparked interest in producing artificial dendritic cells (aDCs) to open up the possibility of standardized "off-the-shelf" protocols and circumvent the cumbersome and expensive personalized medicine. aDCs take advantage of materials that can be designed and tailored for specific clinical applications. Here, an overview of the immunobiology underlying antigen presentation by DCs is provided in an attempt to select the key features to be mimicked and/or improved through the development of aDCs. The inherent properties of aDCs that greatly impact their performance in vivo and, consequently, the fate of the triggered immune response are also outlined.

Nose-to-brain delivery of perampanel formulated in a self-microemulsifying drug delivery system improves anticonvulsant and anxiolytic activity in mice.

Perampanel (PER) is a potent third-generation antiepileptic drug only available for oral administration. Additionally, PER has shown potential in managing epilepsy comorbidities such as anxiety. Previously, we demonstrated that the intranasal (IN) administration of PER, loaded in a self-microemulsifying drug delivery system (SMEDDS), improved brain-targeting and exposure in mice. Herein, we investigated PER brain biodistribution, its anticonvulsant and anxiolytic effects, and its potential olfactory and neuromotor toxicity after IN administration to mice (1 mg/kg). PER showed a rostral-caudal brain biodistribution pattern when administered intranasally. At short times post-nasal dosing, high PER concentrations were found in olfactory bulbs (olfactory bulbs/plasma ratios of 1.266 ± 0.183 and 0.181 ± 0.027 after IN and intravenous administrations, respectively), suggesting that a fraction of the drug directly reaches brain through the olfactory pathway. In the maximal electroshock seizure test, IN PER protected 60% of mice against seizure development, a substantially higher value than the 20% protected after receiving oral PER. PER also demonstrated anxiolytic effects in open field and elevated plus maze tests. Buried food-seeking test showed no signs of olfactory toxicity. Neuromotor impairment was found in rotarod and open field tests at the times of PER maximum concentrations after IN and oral administrations. Nevertheless, neuromotor performance was improved after repeated administrations. Compared with IN vehicle, PER IN administration decreased brain levels of L-glutamate (0.91 ± 0.13 mg/mL vs 0.64 ± 0.12 mg/mL) and nitric oxide (100 ± 15.62% vs 56.62 ± 4.95%), without interfering in GABA levels. Altogether, these results suggest that the IN PER delivery through the developed SMEDDS can be a safe and promising alternative to the oral treatment, which supports the design of clinical studies to evaluate the IN PER delivery to treat epilepsy and neurological-related conditions as anxiety.

Antibody and Nanobody Radiolabeling with Copper-64: Solid vs. Liquid Target Approach.

Antibody and nanobody-based copper-64 radiopharmaceuticals are increasingly being proposed as theranostic tools in multiple human diseases. While the production of copper-64 using solid targets has been established for many years, its use is limited due to the complexity of solid target systems, which are available in only a few cyclotrons worldwide. In contrast, liquid targets, available in virtually in all cyclotrons, constitute a practical and reliable alternative. In this study, we discuss the production, purification, and radiolabeling of antibodies and nanobodies using copper-64 obtained from both solid and liquid targets. Copper-64 production from solid targets was performed on a TR-19 cyclotron with an energy of 11.7 MeV, while liquid target production was obtained by bombarding a nickel-64 solution using an IBA Cyclone Kiube cyclotron with 16.9 MeV on target. Copper-64 was purified from both solid and liquid targets and used to radiolabel NODAGA-Nb, NOTA-Nb, and DOTA-Trastuzumab conjugates. Stability studies were conducted on all radioimmunoconjugates in mouse serum, PBS, and DTPA. Irradiation of the solid target yielded 13.5 ± 0.5 GBq with a beam current of 25 ± 1.2 µA and an irradiation time of 6 h. On the other hand, irradiation of the liquid target resulted in 2.8 ± 1.3 GBq at the end of bombardment (EOB) with a beam current of 54.5 ± 7.8 µA and an irradiation time of 4.1 ± 1.3 h. Successful radiolabeling of NODAGA-Nb, NOTA-Nb, and DOTA-Trastuzumab with copper-64 from both solid and liquid targets was achieved. Specific activities (SA) obtained with the solid target were 0.11, 0.19, and 0.33 MBq/µg for NODAGA-Nb, NOTA-Nb, and DOTA-trastuzumab, respectively. For the liquid target, the corresponding SA values were 0.15, 0.12, and 0.30 MBq/µg. Furthermore, all three radiopharmaceuticals demonstrated stability under the testing conditions. While solid targets have the potential to produce significantly higher activity in a single run, the liquid process offers advantages such as speed, ease of automation, and the feasibility of back-to-back production using a medical cyclotron. In this study, successful radiolabeling of antibodies and nanobodies was achieved using both solid and liquid targets approaches. The radiolabeled compounds exhibited high radiochemical purity and specific activity, rendering them suitable for subsequent in vivo pre-clinical imaging studies.

Intranasal Microemulsion as an Innovative and Promising Alternative to the Oral Route in Improving Stiripentol Brain Targeting.

Stiripentol (STP) is a new-generation antiepileptic only available for oral administration. However, it is extremely unstable in acidic environments and undergoes gastrointestinal slow and incomplete dissolution. Thus, STP intranasal (IN) administration might overcome the high oral doses required to achieve therapeutic concentrations. An IN microemulsion and two variations were herein developed: the first contained a simpler external phase (FS6); the second one 0.25% of chitosan (FS6 + 0.25%CH); and the last 0.25% chitosan plus 1% albumin (FS6 + 0.25%CH + 1%BSA). STP pharmacokinetic profiles in mice were compared after IN (12.5 mg/kg), intravenous (12.5 mg/kg), and oral (100 mg/kg) administrations. All microemulsions homogeneously formed droplets with mean sizes ≤16 nm and pH between 5.5 and 6.2. Compared with oral route, IN FS6 resulted in a 37.4-fold and 110.6-fold increase of STP plasmatic and brain maximum concentrations, respectively. Eight hours after FS6 + 0.25%CH + 1%BSA administration, a second STP brain concentration peak was observed with STP targeting efficiency being 116.9% and direct-transport percentage 14.5%, suggesting that albumin may potentiate a direct STP brain transport. The relative systemic bioavailability was 947% (FS6), 893% (FS6 + 0.25%CH), and 1054% (FS6 + 0.25%CH + 1%BSA). Overall, STP IN administration using the developed microemulsions and significantly lower doses than those orally administrated might be a promising alternative to be clinically tested.

Population Pharmacokinetic Analysis of Perampanel in Portuguese Patients Diagnosed with Refractory Epilepsy.

Perampanel is a promising antiepileptic drug (AED) for refractory epilepsy treatment due to its innovative mechanism of action. This study aimed to develop a population pharmacokinetic (PopPK) model to be further used in initial dose optimization of perampanel in patients diagnosed with refractory epilepsy. A total of seventy-two plasma concentrations of perampanel obtained from forty-four patients were analyzed through a population pharmacokinetic approach by means of nonlinear mixed effects modeling (NONMEM). A one-compartment model with first-order elimination best described the pharmacokinetic profiles of perampanel. Interpatient variability (IPV) was entered on clearance (CL), while the residual error (RE) was modeled as proportional. The presence of enzyme-inducing AEDs (EIAEDs) and body mass index (BMI) were found as significant covariates for CL and volume of distribution (V), respectively. The mean (relative standard error) estimates for CL and V of the final model were 0.419 L/h (5.56%) and 29.50 (6.41%), respectively. IPV was 30.84% and the proportional RE was 6.44%. Internal validation demonstrated an acceptable predictive performance of the final model. A reliable population pharmacokinetic model was successfully developed, and it is the first enrolling real-life adults diagnosed with refractory epilepsy.

Therapeutic Drug Monitoring of Amikacin in Neutropenic Oncology Patients.

Amikacin is the antibiotic of choice for the treatment of Gram-negative infections, namely, those in neutropenic oncology patients. No populational pharmacokinetic studies are currently available reporting amikacin pharmacokinetics in neutropenic oncology patients despite their specific pathophysiological features and treatments. A large-scale retrospective study was herein conducted to specifically investigate the effects that tumor diseases have on the pharmacokinetic parameters of amikacin and identify whether chemotherapy, the lag time between administration of chemotherapy and amikacin, age and renal function contribute to amikacin pharmacokinetics in neutropenic cancer patients. A total of 1180 pharmacokinetic analysis from 629 neutropenic patients were enrolled. The daily dose administered to oncology patients was higher than that administered to non-oncology patients (p < 0.0001). No statistical differences were found in amikacin concentrations, probably because drug clearance was increased in cancer patients (p < 0.0001). Chemotherapy influenced amikacin pharmacokinetics and drug clearance decreased as the lag time enhanced. The elderly group revealed no statistical differences between the doses administered to both the oncology groups, suggesting that the impact of ageing is stronger than chemotherapy. Our research suggests that cancer patients require higher initial doses of amikacin, as well as when chemotherapy is received less than 30 days before amikacin treatment has started.

Air-liquid interface (ALI) impact on different respiratory cell cultures.

The intranasal route has been receiving greater attention from the scientific community not only for systemic drug delivery but also for the treatment of pulmonary and neurological diseases. Along with it, drug transport and permeability studies across the nasal mucosa have exponentially increased. Nevertheless, the translation of data from in vitro cell lines to in vivo studies is not always reliable, due to the difficulty in generating an in vitro model that resembles respiratory human physiology. Among all currently available methodologies, the air-liquid interface (ALI) method is advantageous to promote cell differentiation and optimize the morphological and histological characteristics of airway epithelium cells. Cells grown under ALI conditions, in alternative to submerged conditions, appear to provide relevant input for inhalation and pulmonary toxicology and complement in vivo experiments. Different methodologies and a variety of materials have been used to induce ALI conditions in primary cells and numerous cell lines. Until this day, with only exploratory results, no consensus has been reached regarding the validation of the ALI method, hampering data comparison. The present review describes the most adequate cell models of airway epithelium and how these models are differently affected by ALI conditions. It includes the evaluation of cellular features before and after ALI, and the application of the method in primary cell cultures, commercial 3D primary cells, cell lines and stem-cell derived models. A variety of these models have been recently applied for pharmacological studies against severe acute respiratory syndrome-coronavirus(-2) SARS-CoV(-2), namely primary cultures with alveolar type II epithelium cells and organotypic 3D models. The herein compiled data suggest that ALI conditions must be optimized bearing in mind the type of cells (nasal, bronchial, alveolar), their origin and the objective of the study.

Patients' Characterization, Pattern of Medication Use, and Factors Associated with Polypharmacy: A Cross-Sectional Study Focused on Eight Units of the Portuguese National Network for Long-Term Integrated Care.

The Portuguese National Network for Long-term Integrated Care (RNCCI) comprises several Units for Integrated Continuous Care (UCCIs) that provide medical, nursing, and rehabilitation care. This study aimed to evaluate the demographic and medical characteristics of patients admitted to the RNCCI, their patterns of medication use, and factors associated with polypharmacy. An observational, retrospective, cross-sectional, multicenter study was performed. This study population consisted of 180 patients. Polypharmacy status was divided into two groups: non-polypharmacy (taking ≤ 4 drugs) and polypharmacy (taking ≥ 5 drugs). Bivariate analysis and multivariate logistic regression analysis were used to determine the influence of predictor factors such as demographic and medical characteristics on the polypharmacy status during the UCCI stays. This study population (mean age of 78.4 ± 12.3 years, range 23-102 years, 59% female) was prescribed a median of 8 medications. Approximately 89.4% of the patients were taking ≥ 5 drugs, demonstrating that polypharmacy is highly prevalent in Portuguese RNCCI residents of the eight UCCIs studied. A subsequent analysis with multivariate logistic regression found that polypharmacy status was significantly associated with the unit of internment (facility) when compared to facility E with H and with the Charlson Comorbidity Index (CCI). The high prevalence of polypharmacy and the associated factors show that it is urgent to improve pharmacotherapy regimens through periodic monitoring and review of patients' therapeutic lists, an area in which pharmacists play a very important role.

Anti-Inflammatory and Antimicrobial Activities of Portuguese Prunus avium L. (Sweet Cherry) By-Products Extracts.

The bioactivity of natural by-products in food and pharmaceutical applications is the subject of numerous studies. Cherry production and processing generates large amounts of biowaste, most of which is not used. The recovery of these by-products is essential for promoting the circular economy and to improving sustainability in the food industry. In this work, we explored the anti-inflammatory and antimicrobial potential of two different extracts from stems, leaves, and flowers of Portuguese cherries. The anti-inflammatory potential was studied on lipopolysaccharide (LPS)-stimulated mouse macrophages (RAW 264.7) by evaluating the effect of by-products on cellular viability and nitric oxide (NO) production. Disc diffusion and minimum inhibitory concentration (MIC) were used to determine antimicrobial activity. The cherry by-products had no cytotoxic effect on RAW 264.7 cells, and were able to inhibit nitrite production in a dose-dependent manner. Moreover, all aqueous infusions showed good antioxidant activity against NO radicals. Moreover, leaf extracts showed the best activity against most of the strains studied. The results revealed, for the first time, interesting anti-inflammatory and antimicrobial properties of cherry by-products. This could potentially be of interest for their therapeutic use in the treatment of inflammation-related diseases or in controlling the growth of microorganisms.

Employ of Anthocyanins in Nanocarriers for Nano Delivery: In Vitro and In Vivo Experimental Approaches for Chronic Diseases.

Anthocyanins are among the best-known phenolic compounds and possess remarkable biological activities, including antioxidant, anti-inflammatory, anticancer, and antidiabetic effects. Despite their therapeutic benefits, they are not widely used as health-promoting agents due to their instability, low absorption, and, thus, low bioavailability and rapid metabolism in the human body. Recent research suggests that the application of nanotechnology could increase their solubility and/or bioavailability, and thus their biological potential. Therefore, in this review, we have provided, for the first time, a comprehensive overview of in vitro and in vivo studies on nanocarriers used as delivery systems of anthocyanins, and their aglycones, i.e., anthocyanidins alone or combined with conventional drugs in the treatment or management of chronic diseases.

Osteosarcoma-Derived Exosomes as Potential PET Imaging Nanocarriers for Lung Metastasis.

Lung metastases represent the most adverse clinical factor and rank as the leading cause of osteosarcoma-related death. Nearly 80% of patients present lung micrometastasis at diagnosis not detected with current clinical tools. Herein, an exosome (EX)-based imaging tool is developed for lung micrometastasis by positron emission tomography (PET) using osteosarcoma-derived EXs as natural nanocarriers of the positron-emitter copper-64 (64 Cu). Exosomes are isolated from metastatic osteosarcoma cells and functionalized with the macrocyclic chelator NODAGA for complexation with 64 Cu. Surface functionalization has no effect on the physicochemical properties of EXs, or affinity for donor cells and endows them with favorable pharmacokinetics for in vivo studies. Whole-body PET/magnetic resonance imaging (MRI) images in xenografted models show a specific accumulation of 64 Cu-NODAGA-EXs in metastatic lesions as small as 2-3 mm or in a primary tumor, demonstrating the exquisite tropism of EXs for homotypic donor cells. The targetability for lung metastasis is also observed by optical imaging using indocyanine green (ICG)-labeled EXs and D-luciferin-loaded EXs. These findings show that tumor-derived EXs hold great potential as targeted imaging agents for the noninvasive detection of small lung metastasis by PET. This represents a step forward in the biomedical application of EXs in imaging diagnosis with increased translational potential.

Clinical Application of Pharmacokinetics to Appraise Adherence to Levetiracetam in Portuguese Epileptic Patients.

Adherence to antiseizure drug treatment determines its effectiveness and safety, and consequently affects patients' quality of life. Herein, we assessed adherence to levetiracetam in Portuguese patients with refractory epilepsy (n = 115), with resort to a pharmacokinetic drug monitoring approach. The pharmacokinetic parameters of levetiracetam in each patient were determined in steady-state while admitted to the hospital. Then, adherence was assessed by comparing the plasma concentration of the drug observed on the first day of hospitalization with the predicted plasma concentration, considering previously determined pharmacokinetic parameters. The rate of adherence was assessed according to gender, age, diagnosis, and antiseizure drug regimen. Among 115 enrolled patients, 49 (42.6%) were identified as non-adherent, 30 (26.1%) classified as under-consumers, and 19 (16.5%) as over-consumers. A relationship between adherence, daily dose and plasma concentrations was herein reported for the first time. Adherent patients received higher daily doses of levetiracetam [2500 (2000-3000) mg] than non-adherent over-consumers [1500 (1000-2000) mg] and non-adherent under-consumers [2000 (1500-3000) mg]. Higher average steady-state plasma concentrations of levetiracetam were found in non-adherent under-consumers [27.28 (15.33-36.36) mg/L], followed by adherent patients [22.05 (16.62-29.81) mg/L] and non-adherent over-consumers [17.50 (10.69-24.37) mg/L]. This study demonstrates that adherence (or lack thereof) influences the plasma concentrations of levetiracetam in steady-state and its pharmacological effects. Moreover, it emphasizes the importance of educating patients to encourage adherence to therapy. Otherwise, the risk of developing toxic and subtherapeutic concentrations is undeniable, compromising the therapeutic effect and safety of treatment.

Self-Emulsifying Drug Delivery Systems: An Alternative Approach to Improve Brain Bioavailability of Poorly Water-Soluble Drugs through Intranasal Administration.

Efforts in discovering new and effective neurotherapeutics are made daily, although most fail to reach clinical trials. The main reason is their poor bioavailability, related to poor aqueous solubility, limited permeability through biological membranes, and the hepatic first-pass metabolism. Nevertheless, crossing the blood-brain barrier is the major drawback associated with brain drug delivery. To overcome it, intranasal administration has become more attractive, in some cases even surpassing the oral route. The unique anatomical features of the nasal cavity allow partial direct drug delivery to the brain, circumventing the blood-brain barrier. Systemic absorption through the nasal cavity also avoids the hepatic first-pass metabolism, increasing the systemic bioavailability of highly metabolized entities. Nevertheless, most neurotherapeutics present physicochemical characteristics that require them to be formulated in lipidic nanosystems as self-emulsifying drug delivery systems (SEDDS). These are isotropic mixtures of oils, surfactants, and co-surfactants that, after aqueous dilution, generate micro or nanoemulsions loading high concentrations of lipophilic drugs. SEDDS should overcome drug precipitation in absorption sites, increase their permeation through absorptive membranes, and enhance the stability of labile drugs against enzymatic activity. Thus, combining the advantages of SEDDS and those of the intranasal route for brain delivery, an increase in drugs' brain targeting and bioavailability could be expected. This review deeply characterizes SEDDS as a lipidic nanosystem, gathering important information regarding the mechanisms associated with the intranasal delivery of drugs loaded in SEDDS. In the end, in vivo results after SEDDS intranasal or oral administration are discussed, globally revealing their efficacy in comparison with common solutions or suspensions.