Validation of the 3D reconstructed human skin Comet assay, an animal-free alternative for following-up positive results from standard in vitro genotoxicity assays.

As part of the safety assessment process, all industrial sectors employ genotoxicity test batteries, starting with well-established in vitro assays. However, these batteries have limited predictive capacity for the in vivo situation, which may result in unnecessary follow-up in vivo testing or the loss of promising substances where animal tests are prohibited or not desired. To address this, a project involving regulators, academia and industry was established to develop and validate in vitro human skin-based genotoxicity assays for topically exposed substances, such as cosmetics ingredients. Here, we describe the validation of the 3D reconstructed skin (RS) Comet assay. In this multicenter study, chemicals were applied topically three times to the skin over 48 h. Isolated keratinocytes and fibroblasts were transferred to slides before electrophoresis and the resulting comet formation was recorded as % tail DNA. Before decoding, results of the validation exercise for 32 substances were evaluated by an independent statistician. There was a high predictive capacity of this assay when compared to in vivo outcomes, with a sensitivity of 77 (80)%, a specificity of 88 (97)% and an overall accuracy of 83 (92)%. The numbers reflect the calls of the performing laboratories in the coded phase, whereas those in parenthesis reflect calls according to the agreed evaluation criteria. Intra- and inter-laboratory reproducibility was also very good, with a concordance of 93 and 88%, respectively. These results generated with the Phenion® Full-Thickness skin model demonstrate its suitability for this assay, with reproducibly low background DNA damage and sufficient metabolic capacity to activate pro-mutagens. The validation outcome supports the use of the RS Comet assay to follow up positive results from standard in vitro genotoxicity assays when the expected route of exposure is dermal. Based on the available data, the assay was accepted recently into the OECD test guideline development program.

Chloroquine promotes IL-17 production by CD4+ T cells via p38-dependent IL-23 release by monocyte-derived Langerhans-like cells.

Recent studies suggest a role for autophagy in the secretion of IL-1 cytokines regulating the development of inflammatory diseases. The antimalarial drug and autophagy/lysosome inhibitor chloroquine (CHQ) is considered as potential trigger of drug-induced or drug-aggravated psoriasis, in which Th17 cells sustain a persistent inflammation. In this study, we investigated the effect of CHQ on human monocyte-derived Langerhans-like cells (MoLC) and dendritic cells (MoDC) in response to IL-1ß. The presence of CHQ reduced IL-12p70 release in both subsets, but surprisingly increased IL-6 production in MoDC and IL-23 in MoLC. Importantly, CHQ-treated MoLC promoted IL-17A secretion by CD4(+) T cells and elevated RORC mRNA levels, whereas IFN-γ release was reduced. The dysregulation of IL-12 family cytokines in MoLC and MoDC occurred at the transcriptional level. Similar effects were obtained with other late autophagy inhibitors, whereas PI3K inhibitor 3-methyladenine failed to increase IL-23 secretion. The modulated cytokine release was dependent on IL-1 cytokine activation and abrogated by a specific IL-1R antagonist. CHQ elevated expression of TNFR-associated factor 6, a common intermediate in IL-1R and TLR-dependent signaling. Accordingly, treatment with Pam3CSK4 and CHQ enhanced IL-23 release in MoLC and MoDC. CHQ inhibited autophagic flux, confirmed by increased LC3-II and p62 expression, and activated ERK, p38, and JNK MAPK, but only inhibition of p38 abrogated IL-23 release by MoLC. Thus, our findings indicate that CHQ modulates cytokine release in a p38-dependent manner, suggesting an essential role of Langerhans cells and dendritic cells in CHQ-provoked psoriasis, possibly by promoting Th17 immunity.

Inflammatory conditions distinctively alter immunological functions of Langerhans-like cells and dendritic cells in vitro.

The specific function of human skin-resident dendritic cell (DC) subsets in the regulation of immunity or tolerance is still a matter of debate. Langerhans cells (LC) induce anti-viral immune responses but, conversely to dermal DC, maintain tolerance to bacteria. However, the definite function of epidermal LC and cutaneous DC appears even more complex under inflammatory conditions. Here we investigated the immune responses of human immature monocyte-derived DC (MoDC) and LC-like cells (MoLC) upon stimulation with different Toll-like receptor ligands in the presence or absence of pro-inflammatory cytokines tumour necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß). In MoDC, bacterial antigens selectively up-regulated CD83 and CD86 expression and induced the release of T helper type 1 (Th1) and Th17 cytokines and led to a higher CCR7-dependent migratory capacity compared with a low responsiveness of MoLC. Importantly, MoLC activation with lipopolysaccharide under inflammatory conditions strongly enhanced a phenotypically mature state, increased IL-12p70, IL-23 and IL-6 production and Th1 cytokine secretion by CD4(+) T cells. Treatment with poly(I:C) specifically up-regulated surface expression of co-stimulatory molecules and increased release of IL-12p70 in MoLC and co-stimulation with TNF-α and IL-1ß further elevated Th1 and Th17 cytokine production. Poly(I:C)-induced up-regulation of type I interferon mRNA levels in MoLC and MoDC was Toll-like receptor 3-dependent but not, or only weakly, modulated by pro-inflammatory cytokines. Our results indicate that inflammatory conditions greatly facilitate recognition of bacteria by MoLC. Furthermore, we suggest a critical involvement of both subsets in innate defence against viruses, whereas inflammatory skin environments additionally favour MoLC as potent inducers of Th1 and Th17 cytokines.

Oral Drugs Against COVID-19.

BACKGROUND: Five-day oral therapies against early COVID-19 infection have recently been conditionally approved in Europe. In the drug combination nirmatrelvir + ritonavir (nirmatrelvir/r), the active agent, nirmatrelvir, is made bioavailable in clinically adequate amounts by the additional administration of a potent inhibitor of its first-pass metabolism by way of cytochrome P450 [CYP] 3A in the gut and liver. In view of the central role of CYP3A in the clearance of many different kinds of drugs, and the fact that many patients with COVID-19 are taking multiple drugs to treat other conditions, it is important to assess the potential for drug interactions when nirmatrelvir/r is given, and to minimize the risks associated with such interactions. METHODS: We defined the interaction profile of ritonavir on the basis of information derived from two databases (Medline, GoogleScholar), three standard electronic texts on drug interactions, and manufacturer-supplied drug information. We compiled a list of drugs and their potentially relevant interactions, developed a risk min - imization algorithm, and applied it to the substances in question. We also compiled a list of commonly prescribed drugs for which there is no risk of interaction with nirmatrelvir/r. RESULTS: Out of 190 drugs and drug combinations, 57 do not need any special measures when given in combination with brief, low-dose ritonavir treatment, while 15 require dose modification or a therapeutic alternative, 8 can be temporarily discontinued, 9 contraindicate ritonavir use, and 102 should preferably be combined with a different treatment. CONCLUSION: We have proposed measures that are simple to carry out for the main types of drug that can interact with ritonavir. These measures can be implemented under quarantine conditions before starting a 5-day treatment with nirmatrelvir/r.

Pharmacists' perception of educational material to improve patient safety: A cross-sectional study on practices and awareness in Germany.

ABSTRACT: Educational material (EM) addresses particular safety information of medicinal products to healthcare professionals and patients. Since 2016, German national competent authorities label approved EM with a Blue Hand symbol. However, data is scarce regarding its usability as a safety communication tool in pharmacies to improve patient safety. The purpose of this study is to investigate for the first time pharmacists' awareness and perception of EM in the setting of community and hospital pharmacies in Germany.The Drug Commission of German Pharmacists surveyed its nationwide network of 677 community and 51 hospital reference pharmacies, to investigate their awareness and perception of EM. The survey was conducted between January 16 and February 10, 2020 using SurveyMonkey. Data were analyzed using Microsoft Excel.A total of 373 community and 32 hospital pharmacists participated; response rates were 55.1% and 62.8%, respectively. Overall, 320 (85.8%) community and all hospital pharmacists confirmed awareness of EM. Community and hospital pharmacists fully (n = 172, 46.9% and n = 9, 28.1%) or rather (n = 109, 29.7% and n = 10, 31.3%) agreed that EM for healthcare professionals is suitable to reduce risks of medicinal products. Moreover, 237 (64.7%) community and 17 (53.1%) hospital pharmacists confirmed to inform patients or care facilities about EM. Asking pharmacists on their personal perception of EM, the refinement of readability and accessibility was indicated.Pharmacists confirm awareness of EM and its suitability as a safety communication tool. However, from a pharmacists' perspective, the applicability and readability of EM still needs further adjustment to improve patient safety.

Primary healthcare policy and vision for community pharmacy and pharmacists in Germany.

Germany is the highest populated country in Europe with a population of 82.3 million in 2019. As in many other developed countries, it has an aging population. Approximately 10% of the gross domestic product is spent on healthcare. The healthcare system is characterized by its accessibility. Patients are generally free to choose their primary care physicians, both family doctors and specialists, pharmacy, dentist, or emergency service. Up to a certain income, health insurance is mandatory with the statutory health insurance (SHI) system, covering 88% of the population. Major challenges are the lack of cooperation and integration between the different sectors and healthcare providers. This is expected to change with the introduction of a telematic infrastructure that is currently being implemented. It will not only connect all providers in primary and secondary care in a secure network but will also enable access to patients' electronic record/medical data and at the same time switch from paper to electronic prescriptions. Approximately 52,000 of the 67,000 pharmacists are working in approximately 19,000 community pharmacies. These pharmacies are owner-operated by a pharmacist. Pharmacists may own up to three subsidiaries nearby to their main pharmacy. Community pharmacy practice mainly consists of dispensing drugs, counselling patients on drug therapy and safety, and giving advice on lifestyle and healthy living. Many cognitive pharmaceutical services have been developed and evaluated in the past 20 years. Discussions within the profession and with stakeholders on the national level on the roles and responsibilities of pharmacists have resulted in nationally agreed guidelines, curricula, and services. However, cognitive services remunerated by the SHI funds on the national level remain to be negotiated and sustainably implemented. A law passed in November 2020 by parliament will regulate the remuneration of pharmaceutical services by the SHI funds with an annual budget of EUR 150 million. The type of services and their remuneration remain to be negotiated in 2021. The profession has to continue on all levels to advocate for a change in pharmacy practice by introducing pharmacy services into routine care.

Effect of Poly(L-lysine) and Heparin Coatings on the Surface of Polyester-Based Particles on Prednisolone Release and Biocompatibility.

A plethora of micro- and nanoparticle types are currently investigated for advanced ocular treatment due to improved drug retention times, higher bioavailability and better biocompatibility. Yet, comparative studies of both physicochemical and toxicological performance of these novel drug delivery systems are still rare. Herein, poly(L-lactic acid)- and poly(ε-caprolactone)-based micro- and nanoparticles were loaded with prednisolone as a model drug. The physicochemical properties of the particles were varied with respect to their hydrophilicity and size as well as their charge and the effect on prednisolone release was evaluated. The particle biocompatibility was assessed by a two-tier testing strategy, combining the EpiOcularTM eye irritation test and bovine corneal opacity and permeability assay. The biodegradable polyelectrolyte corona on the particles' surface determined the surface charge and the release rate, enabling prednisolone release for at least 30 days. Thereby, the prednisolone release process was mainly governed by molecular diffusion. Finally, the developed particle formulations were found to be nontoxic in the tested range of concentrations.

Development and implementation of blood pressure screening and referral guidelines for German community pharmacists.

Involvement of community pharmacists in the detection and control of hypertension improves patient care. However, current European or North-American guidelines do not provide specific guidance how to implement collaboration between pharmacists and physicians, especially when and how to refer patients with undetected or uncontrolled hypertension to a physician. The German Society of Cardiology and the ABDA - Federal Union of German Associations of Pharmacists developed and tested referral recommendations for community pharmacists, embedded in two guideline worksheets. The project included a guideline-directed blood pressure (BP) measurement and recommendations when patients should be referred to their physician. A "red flag" referral within 4 weeks was recommended when SBP was >140 mm Hg or DBP >90 mm Hg (for subjects <80 years), and >160 mm Hg or >90 mm Hg (≥80 years) in undetected individuals, or >130 mm Hg or >80 mm Hg (<65 years) and >140 mm Hg or >80 mm Hg (≥65 years) in treated patients. BP was measured in 187 individuals (86 with known hypertension, mean [±SD] age 62 ± 15 years, 64% female, and 101 without known hypertension, 47 ± 16 years, 75% female) from 17 community pharmacies. In patients with hypertension, poorly controlled BP was detected in 55% (n = 47) and were referred. A total of 16/101 subjects without a history of hypertension were referred to their physician because of uncontrolled BP. Structured BP testing in pharmacies identified a significant number of subjects with undetected/undiagnosed hypertension and patients with poorly controlled BP. Community pharmacists could play a significant role in collaboration with physicians to improve the management of hypertension.

Trends in dispensing oral emergency contraceptives and safety issues: a survey of German community pharmacists.

Background Oral emergency contraceptives containing levonorgestrel or ulipristal acetate are available without prescription and only in pharmacies in Germany since March 2015. Due to this change community pharmacists are responsible for evaluating whether the product is appropriate and to educate women on proper use. Objective To measure the utilization of emergency contraceptives without a prescription and describe potential concerns and safety issues identified by community pharmacists in Germany. Setting The Drug Commission of German Pharmacists' nationwide network of reference pharmacies which includes 860 community pharmacies. Methods Reference community pharmacies were asked to participate in the eleven-questions online survey. Respondents were asked to recall their experiences with oral emergency contraceptives in the past 3 months. Data were collected between January 8 and February 19, 2018. Main outcome measure The survey focused on the utilization of emergency contraceptives without a prescription in Germany, and on the pharmacists' experiences with (potential) problems and concerns regarding safe use. Results In total, 555 community pharmacies (64.5%) participated. Overall 38.2% of community pharmacists stated they dispensed six to ten courses of emergency contraceptives within the past 3 months. In addition, 54.3% of the pharmacists estimated they dispensed emergency contraceptives exclusively without prescription and 35.9% dispensed more than 30% of emergency contraceptives during night-time and emergency services. Moreover, 82.8% of pharmacists stated that emergency contraceptives were requested not by the women concerned but a third person and 44.3% identified uncertainties in woman's self-diagnosis. Three out of four pharmacists had concerns about the effective and safe use of emergency contraceptives. In situations suggesting sexually transmitted diseases, or suspicion for use of force, 59.5% and 55.8% of the pharmacists, respectively, dispensed emergency contraceptives. In cases of acute health impairment or chronic disease, or (potentially) relevant drug/drug interaction, the vast majority (91.0% and 90.5%) did not. Here, most pharmacists referred to gynecologists. Conclusion Pharmacists had safety concerns when dispensing emergency contraceptives. Professional expertise in evaluating the need for oral emergency contraceptives and the proper use is needed.

Characterization of reconstructed human skin containing Langerhans cells to monitor molecular events in skin sensitization.

Human cell-based approaches to assess defined key events in allergic contact dermatitis (ACD) are well-established, but lack cutaneous penetration and biotransformation as well as cellular cross-talk. Herein, we integrated in vitro-generated immature MUTZ-3-derived Langerhans-like cells (MUTZ-LCs) or monocyte-derived LC-like cells (MoLCs) into reconstructed human skin (RHS), consistent of a stratified epidermis formed by primary keratinocytes on a dermal compartment with collagen-embedded primary fibroblasts. LC-like cells were mainly localized in the epidermal compartment and distributed homogenously in accordance with native human skin. Topical application of the strong contact sensitizer 2,4-dinitrochlorobenzene (DNCB) induced IL-6 and IL-8 secretion in RHS with LC-like cells, whereas no change was observed in reference models. Increased gene expression of CD83, PD-L1, and CXCR4 in the dermal compartment indicated LC maturation. Importantly, exposure to DNCB enhanced mobility of the LC-like cells from epidermal to dermal compartments. In response to the moderate sensitizer isoeugenol and irritant sodium dodecyl sulphate, the obtained response was less pronounced. In summary, we integrated immature and functional MUTZ-LCs and MoLCs into RHS and provide a unique comparative experimental setting to monitor early events during skin sensitization.

Drug shortages may compromise patient safety: Results of a survey of the reference pharmacies of the Drug Commission of German Pharmacists.

Drug shortages are a complex problem and of growing concern. To evaluate implications of drug shortages in terms of outpatient and inpatient safety, the Drug Commission of German Pharmacists surveyed its two nationwide reference pharmacy networks: 865 community and 54 hospital pharmacies. Participants were asked to complete a six-question online survey, covering relevance and challenges of drug shortages in everyday practice as well as consequences for patient safety. Answers were given in the context of the last three months prior to the survey. In total, 482 community (55.7%) and 36 hospital pharmacies (66.7%) participated. Occurrence of drug shortages were confirmed by 88.6% of community and 80.6% of hospital pharmacies. Thus, for example, a substitute was dispensed more than 15 times (60.7% of community, 44.8% of hospital pharmacies) during the 3-month-period. Comparing community and hospital pharmacies, differences in the incidence or severity of consequences for patient safety were apparent. Community pharmacies mainly confirmed adverse effects on patients' medication adherence (60.4%) and treatment discontinuation (25.8%). A delay or deny of a life-saving treatment (39.4%) was largely reported by hospital pharmacies. Medication errors were reported by 20.1% of the community and 21.2% of the hospital pharmacies, respectively. Taken together, sustainable solutions are needed to counteract drug shortages and to ensure adequate treatment for patients.

Poly[acrylonitrile-co-(N-vinyl pyrrolidone)] nanoparticles - Composition-dependent skin penetration enhancement of a dye probe and biocompatibility.

Nanoparticles can improve topical drug delivery: size, surface properties and flexibility of polymer nanoparticles are defining its interaction with the skin. Only few studies have explored skin penetration for one series of structurally related polymer particles with systematic alteration of material composition. Here, a series of rigid poly[acrylonitrile-co-(N-vinyl pyrrolidone)] model nanoparticles stably loaded with Nile Red or Rhodamin B, respectively, was comprehensively studied for biocompatibility and functionality. Surface properties were altered by varying the molar content of hydrophilic NVP from 0 to 24.1% and particle size ranged from 35 to 244nm. Whereas irritancy and genotoxicity were not revealed, lipophilic and hydrophilic nanoparticles taken up by keratinocytes affected cell viability. Skin absorption of the particles into viable skin ex vivo was studied using Nile Red as fluorescent probe. Whilst an intact stratum corneum efficiently prevented penetration, almost complete removal of the horny layer allowed nanoparticles of smaller size and hydrophilic particles to penetrate into viable epidermis and dermis. Hence, systematic variations of nanoparticle properties allows gaining insights into critical criteria for biocompatibility and functionality of novel nanocarriers for topical drug delivery and risks associated with environmental exposure.

Biocompatibility and characterization of polyglycerol-based thermoresponsive nanogels designed as novel drug-delivery systems and their intracellular localization in keratinocytes.

Novel nanogels that possess the capacity to change their physico-chemical properties in response to external stimuli are promising drug-delivery candidates for the treatment of severe skin diseases. As thermoresponsive nanogels (tNGs) are capable of enhancing penetration through biological barriers such as the stratum corneum and are taken up by keratinocytes of human skin, potential adverse consequences of their exposure must be elucidated. In this study, tNGs were synthesized from dendritic polyglycerol (dPG) and two thermoresponsive polymers. tNG_dPG_tPG are the combination of dPG with poly(glycidyl methyl ether-co-ethyl glycidyl ether) (p(GME-co-EGE)) and tNG_dPG_pNIPAM the one with poly(N-isopropylacrylamide) (pNIPAM). Both thermoresponsive nanogels are able to incorporate high amounts of dexamethasone and tacrolimus, drugs used in the treatment of severe skin diseases. Cellular uptake, intracellular localization and the toxicological properties of the tNGs were comprehensively characterized in primary normal human keratinocytes (NHK) and in spontaneously transformed aneuploid immortal keratinocyte cell line from adult human skin (HaCaT). Laser scanning confocal microscopy revealed fluorescently labeled tNGs entered into the cells and localized predominantly within lysosomal compartments. MTT assay, comet assay and carboxy-H2DCFDA assay, demonstrated neither cytotoxic or genotoxic effects, nor any induction of reactive oxygen species of the tNGs in keratinocytes. In addition, both tNGs were devoid of eye irritation potential as shown by bovine corneal opacity and permeability (BCOP) test and red blood cell (RBC) hemolysis assay. Therefore, our study provides evidence that tNGs are locally well tolerated and underlines their potential for cutaneous drug delivery.

Regulation of Dendritic Cell Function in Inflammation.

Dendritic cells (DC) are professional antigen presenting cells and link the innate and adaptive immune system. During steady state immune surveillance in skin, DC act as sentinels against commensals and invading pathogens. Under pathological skin conditions, inflammatory cytokines, secreted by surrounding keratinocytes, dermal fibroblasts, and immune cells, influence the activation and maturation of different DC populations including Langerhans cells (LC) and dermal DC. In this review we address critical differences in human DC subtypes during inflammatory settings compared to steady state. We also highlight the functional characteristics of human DC subsets in inflammatory skin environments and skin diseases including psoriasis and atopic dermatitis. Understanding the complex immunoregulatory role of distinct DC subsets in inflamed human skin will be a key element in developing novel strategies in anti-inflammatory therapy.