Live chicken egg embryos as an alternative in vivo tumour model for deep surface enhanced Raman spectroscopy.

Live chicken egg embryos offer new opportunities for evaluation and continuous monitoring of tumour growth for in vivo studies compared to traditional rodent models. Here, we report the first use of surface enhanced Raman scattering (SERS) mapping and surface enhanced spatially offset Raman scattering (SESORS) for the detection and localisation of targeted gold nanoparticles in live chicken egg embryos bearing a glioblastoma tumour.

Sepsis scoring systems and use of the Sepsis six care bundle in maternity hospitals.

BACKGROUND: This study aimed to assess the predictive power of three different Sepsis Scoring Systems (SSSs), namely maternity Systematic Inflammatory Response Syndrome (mSIRS), quick Sepsis-related Organ Failure Assessment (qSOFA) and Modified Early Warning System (MEWS) in identifying sepsis by comparing them with positive culture. This study also sought to evaluate compliance with using the Sepsis Six Care Bundle (SSCB) operated in an individual health board. METHODS: A retrospective cohort study was conducted in 3 maternity hospitals of a single Scottish health board that admitted 2690 pregnancies in a 12 weeks period in 2016. Data for study was obtained from medical notes, handheld and electronic health records for women who were prescribed antibiotics with a confirmed or suspected diagnosis of sepsis. Data on clinical parameters was used to classify women according to mSIRS, qSOFA and MEWS as having sepsis or not and this was compared to results of positive culture to obtain sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and area under Receiver Operating Characteristic curve (AUROC) along with their 95% confidence intervals. Data was also obtained on SSCB compliance. RESULTS: A total of 89 women were diagnosed with sepsis, of which 14 had missing data, leaving 75 for final analysis. Sensitivity, specificity, PPV, NPV and AUROC of mSIRS and MEWS were almost similar with AUROC of both being around 50%. Only 33 (37.1%) had identifiable sepsis six sticker displayed on medical notes and only 2 (2.2%) had all elements of SSCB delivered within the recommended one-hour post-diagnosis period. Blood culture and full blood count with other lab tests had been performed for most women (97%) followed by intravenous antibiotics and fluids (93.9%). CONCLUSIONS: mSIRS and MEWS were quite similar in detecting sepsis when compared to positive culture, with their ability to detect sepsis being close to chance. This underlines the need for creating a valid SSS with high sensitivity and specificity for clinical use in obstetric settings. Clinical use of SSCB was limited despite it being a health board policy, although there is considerable possibility of improvement following detailed audits and removal of barriers for implementing SSCB.

Antileishmanial efficacy and tolerability of combined treatment with non-ionic surfactant vesicle formulations of sodium stibogluconate and paromomycin in dogs.

Infection with Leishmania infantum causes the disease visceral leishmaniasis (VL), which is a serious clinical and veterinary problem. The drugs used to treat canine leishmaniasis (CanL) do not cause complete parasite clearance; they can be toxic, and emerging drug resistance in parasite populations limits their clinical utility. Therefore, in this study we have evaluated the toxicity and efficacy of joint treatment with a 1:1 mixture of sodium stibogluconate-NIV (SSG-NIV, 10 mg Sbv/day) and paromomycin-NIV (PMM-NIV, 10 mg PMM/kg/day), given intravenously daily for seven days from day 270 post-infection, to nine-month-old female beagle dogs (n = 6) experimentally infected with Leishmania infantum. Treatment significantly improved the clinical symptoms of VL infection in all the treated dogs, reduced parasite burdens in lymph nodes and bone marrow, and all symptomatic treated dogs, were asymptomatic at 90 days post-treatment. Treatment was associated with a progressive and significant decrease in specific IgG anti-Leishmania antibodies using parasite soluble antigen (p < 0.01) or rK39 (p < 0.01) as the target antigen. In addition, all dogs were classified as parasite negative based on Leishmania nested PCR and quantitative real time PCR tests and as well as an inability to culture of promastigote parasites from lymph nodes and bone marrow tissue samples taken at day 90 post-treatment. However, treatment did not cure the dogs as parasites were detected at 10 months post-treatment, indicating that a different dosing regimen is required to cause long term cure or prevent relapse.

Evaluating the appropriateness of carbapenem and piperacillin-tazobactam prescribing in a tertiary care hospital in Saudi Arabia.

BACKGROUND: Antimicrobial resistance (AMR) is presently considered an emergent major global public health concern and excessive and/or inappropriate use of broad-spectrum antimicrobials contribute to the development of AMR. OBJECTIVE: To evaluate the appropriateness of carbapenems and piperacillin-tazobactam use in a tertiary care hospital. METHODS: A retrospective, observational, cross-sectional, drug-utilization study was conducted. The study included all adult hospitalized patients who had received at least one dose of the antimicrobials during their admission for the period between 1 January 2016 and 31 December 2017. The appropriateness of antimicrobial therapy was evaluated according to the Infectious Diseases Society of America (IDSA) guidelines with the consideration of the institutional antibiogram. RESULTS: Overall, 2731 patients received 5005 courses with one of the antimicrobials, for a total of 5045.9 defined daily doses (DDD) of imipenem-cilastatin, 6492.3 of meropenem and 15,595 of piperacillin-tazobactam (4.93, 6.34 and 15.24 DDD/100 bed days, respectively). The mean age of the patients who received either antimicrobial was 55.5 ± 20.3 years, with a 14-day average length of hospital stay. About half (52%) of the prescriptions were written for patients treated in the medical ward. Pneumonia (26.6%) and sepsis (24.9%) were the most common indication for the initiation of antimicrobial therapy. Of the assessed prescriptions, only 2787 (56.5%) were prescribed appropriately, with 2142 (43.5%) deemed inappropriate. The three most common reasons for inappropriate prescription were: the spectrum of activity was too broad (44.6%), followed by antimicrobial use without culture request (32.4%), and failure of suitable antimicrobial de-escalation (19.9%). CONCLUSIONS: The study indicates that the overall rate of inappropriateness was high, emphasizing the need to develop initiatives to effectively improve broad-spectrum antimicrobial prescribing.

Proof of concept studies for siRNA delivery by nonionic surfactant vesicles: in vitro and in vivo evaluation of protein knockdown.

RNA interference is an effective and naturally occurring post-transcriptional gene regulatory mechanism. This mechanism involves the degradation of a target messenger RNA (mRNA) through the introduction of short interfering RNA (siRNA) that is complementary to the target mRNA. The application of siRNA-based therapeutics is limited by the development of an effective delivery system, as naked siRNA is unstable and cannot penetrate the cell membrane. In this study, we investigated the use of cationic niosomes (CN) prepared by microfluidic mixing for siRNA delivery. In an in vitro model, these vesicles were able to deliver anti-luciferase siRNA and effectively suppress luciferase expression in B16-F10 mouse melanoma cells. More importantly, in an in vivo mouse model, intratumoral administration of CN-carrying anti-luciferase siRNA led to significant suppression of luciferase expression compared with naked siRNA. Thus, we have established a novel and effective system for the delivery of siRNA both in vitro and in vivo, which shows high potential for future application of gene therapeutics.

Optimizing carbapenem use through a national quality improvement programme.

Background: Concern about increasing carbapenem and piperacillin/tazobactam use led the Scottish Antimicrobial Prescribing Group (SAPG) to develop national guidance on optimal use of these agents, and to implement a quality improvement programme to assess the impact of guidance on practice. Objectives: To evaluate how SAPG guidance had been implemented by health boards, assess how this translated into clinical practice, and investigate clinicians' views and behaviours about prescribing carbapenems and alternative agents. Methods: Local implementation of SAPG guidance was assessed using an online survey. A bespoke point prevalence survey was used to evaluate prescribing. Clinicians' experience of using carbapenems and alternatives was examined through semi-structured interviews. National prescribing data were analysed to assess the impact of the programme. Results: There were greater local restrictions for carbapenems than for piperacillin/tazobactam. Laboratory result suppression was inconsistent between boards and carbapenem-sparing antibiotics were not widely available. Compliance with local guidelines was good for meropenem but lower for piperacillin/tazobactam. Indication for use was well documented but review/stop dates were poorly documented for both antibiotics. Decisions to prescribe a carbapenem were influenced by local guidelines and specialist advice. Many clinicians lacked confidence to de-escalate treatment. Use of both antibiotics decreased during the course of the programme. Conclusions: A multifaceted quality improvement programme was used to gather intelligence, promote behaviour change, and focus interventions on the use of carbapenems and piperacillin/tazobactam. Use of these antimicrobials decreased during the programme-a trend not seen elsewhere in Europe. The programme could be generalized to other antimicrobials.

Formulation of Nonionic Surfactant Vesicles (NISV) Prepared by Microfluidics for Therapeutic Delivery of siRNA into Cancer Cells.

Small interfering RNAs (siRNA) have a broad potential as therapeutic agents to reversibly silence any target gene of interest. The clinical application of siRNA requires the use of safe and effective delivery systems. In this study, we investigated the use of nonionic surfactant vesicles (NISV) for the delivery of siRNA. Different types of NISV formulations were synthesized by microfluidic mixing and then evaluated for their physiochemical properties and cytotoxicity. The ability of the NISV to carry and transfect siRNA targeting green fluorescent protein (GFP) into A549 that stably express GFP (copGFP-A549) was evaluated. Flow cytometry and Western blotting were used to study the GFP expression knockdown, and significant knockdown was observed as a result of siRNA delivery to the cells by NISV. This occurred in particular when using Tween 85, which was able to achieve more than 70% GFP knockdown. NISV were thus demonstrated to provide a promising and effective platform for therapeutic delivery of siRNA.

An association between socioeconomic deprivation and primary care antibiotic prescribing in Scotland.

OBJECTIVE: To evaluate the association between socioeconomic deprivation and antibiotic prescribing in Scotland. PATIENTS AND METHODS: Data for dispensed antibiotic prescriptions written by general practitioners were obtained for all Scottish National Health Service boards from 2010 to 2012. Deprivation was assessed linking dispensing events to the Scottish Index of Multiple Deprivation (SIMD) score for the patient's datazone (neighbourhood area). The relationship between the deprivation area and antibiotic use (items per 1000 persons per day) was stratified according to the patient's age and sex and the antibiotic class dispensed. A multivariate Poisson regression model was used to formally test the associations. RESULTS: Approximately 12 million prescription items during 2010-2012 were assessed. Patients in the most deprived SIMD quintile had an overall prescription rate that was 36.5% higher than those in the least deprived quintile. The effect of deprivation upon prescription rates was most pronounced for women aged 40-59 years, and for penicillins and metronidazole. CONCLUSIONS: Deprivation was found to have a consistent association with increased rates of antibiotic prescribing in Scotland, which may have significant implications for antimicrobial stewardship and public health campaigns.

Assessment of the antigen-specific antibody response induced by mucosal administration of a GnRH conjugate entrapped in lipid nanoparticles.

Vaccines administered parenterally have been developed against gonadotrophin-releasing hormone (GnRH) for anti-fertility and anti-cancer purposes. The aim of this study was to demonstrate whether mucosal delivery using GnRH immunogens entrapped in lipid nanoparticles (LNP) could induce anti-GnRH antibody titers. Immunogens consisting of KLH (keyhole limpet hemocyanin) conjugated to either GnRH-I or GnRH-III analogues were entrapped in LNP. Loaded non-ionic surfactant vesicles (NISVs) were administered subcutaneously, while nasal delivery was achieved using NISV in xanthan gum and oral delivery using NISV containing deoxycholate (bilosomes). NISV and bilosomes had similar properties: they were spherical, in the nanometre size range, with a slightly negative zeta potential and surface properties that changed with protein loading and inclusion of xanthan gum. Following immunization in female BALB/c mice, systemic antibody responses were similar for both GnRH-I and GnRH-III immunization. Only nasal delivery proved to be successful in terms of producing systemic and mucosal antibodies. FROM THE CLINICAL EDITOR: The main research question addressed in this study was whether mucosal delivery using gonadotrophin-releasing hormone immunogens entrapped in lipid nanoparticles could induce anti-GnRH antibody titers. Only nasal delivery proved to be successful in terms of producing systemic and mucosal antibodies with this approach.

Pharmaceutical care issues in lung cancer: can community pharmacists support patients receiving systemic anticancer therapy?

OBJECTIVES: Most patients receive systemic anticancer therapy (SACT) as day cases and toxicities, if they occur, are likely to appear first in primary care. Pharmaceutical care can be delivered by community pharmacists, but little is known about the epidemiology of SACT toxicities in the community and potential interventions to address these which raise the following questions: what are the typologies of SACT-associated toxicities experienced by community-based patients and what are the associated pharmaceutical care issues (PCIs)? The aim of this study was to identify toxicities and pharmaceutical care issues of patients prescribed SACT for lung cancer and understand the potential for community pharmacists to deliver aspects of cancer care including toxicity management. METHODS: Retrospective analysis of clinical records of patients prescribed oral and parenteral SACT in 2013-14, to describe patient characteristics; SACT toxicity; PCIs and episodes of unscheduled care. KEY FINDINGS: Twelve categories of toxicity and 13 categories of PCIs were identified from 50 patients. More PCIs were observed with oral SACT/oral-parenteral combinations than with parenteral regimens. The PCIs which could be managed by community pharmacists were mucositis; skin toxicity; gastrointestinal toxicity; reinforcing patient education and identification/prevention of drug interactions. CONCLUSIONS: Community pharmacists are ideally placed to provide pharmaceutical care to patients with lung cancer prescribed SACT. Cancer specialists in secondary care can signpost patients to community pharmacists for early management of low-grade SACT toxicity.

Exploring Physicians' Views, Perceptions and Experiences about Broad-Spectrum Antimicrobial Prescribing in a Tertiary Care Hospital Riyadh, Saudi Arabia: A Qualitative Approach.

Antimicrobial resistance (AMR) is a global public health threat associated with increased mortality, morbidity and costs. Inappropriate antimicrobial prescribing, particularly of broad-spectrums antimicrobials (BSAs), is considered a major factor behind growing AMR. The aim of this study was to explore physician perception and views about BSAs and factors that impact upon their BSAs prescribing decisions. Qualitative semistructured telephone interviews over an eleven-week period were conducted with physicians in a single tertiary care hospital in Riyadh, Saudi Arabia. Purposeful and snowball sampling techniques were adopted as sampling strategy. All interviews were audio recorded, transcribed verbatim, uploaded to NVivo® software and analysed following thematic analysis approach. Four major themes emerged: views on BSAs, factors influencing BSA prescribing and antimicrobial stewardship: practices and barriers and recommendations to improve appropriate BSA prescribing. Recommendations for the future include improving clinical knowledge, feedback on prescribing, multidisciplinary team decision-making and local guideline implementation. Identification of views and determinants of BSA prescribing can guide the design of a multifaceted intervention to support physicians and policymakers to improve antimicrobial prescribing practices.

Translational modifications to improve vaccine efficacy in an oral influenza vaccine.

Oral vaccination using protein antigens is complicated by the degradative effects of the inhospitable conditions in the gastrointestinal tract, such as low pH and digestive enzymes, nescessitating protection and effective delivery of the antigen. The bilosome is a lipid-based, vesicle delivery system incorporating bile salts, which is believed to protect the antigen from degradation, and has been shown to induce significant antibody responses when delivered orally with various vaccines. In translational research, from laboratory bench to industrial scale-up, it is necessary to optimise the manufacturing process in order to improve efficiency and simplify production, giving a more economical end-product. In this study we tested two simplified production methods (3-step and 1-step) along with two different storage methods (lyophilised and non-lyophilised), as well as looking at the effect of buffer pH. The formulations were assessed in a murine system for immunogenicity, alongside characterisation in terms of size and antigen entrapment, with the stability of these aspects assessed with respect to time. Both lyophilised and non-lyophilised 3-step formulations induced significant IgG1, IgG2a and IgA titres, with the lyophilised version showing stable size and antigen entrapment up to 9months.

An Observational Cohort Study Evaluating Antimicrobial Use in Peripartum Sepsis: A Tendency towards Overdiagnosis?

(1) Background: Sepsis is the leading cause of maternal death in 11-15% of women worldwide. This emphasises the importance of administrating timely and appropriate antibiotic therapy to women with sepsis. We aimed to evaluate the appropriateness of antimicrobial prescribing in women diagnosed with peripartum sepsis. (2) Method: A prospective observational cohort study in a single Scottish health region with 12,233 annual live births. Data were collected on women diagnosed with sepsis in the peripartum period using physical and electronic medical records, drug Kardex® (medication administration) and ward handover records. (3) Results: A sepsis diagnosis was concluded in 89 of the 2690 pregnancy cases reviewed, with a median hospital stay of four days. Good overall adherence to the local guidelines for the empiric antimicrobial treatment of sepsis was observed. Group B Streptococcus was associated with 20.8% of maternal sepsis cases, whilst in 60% of clinical specimens tested no causative pathogen was isolated. (4) Conclusion: The lack of specific and sensitive clinical markers for sepsis, coupled with their inconsistent clinical application to inform diagnosis, hindered effective antimicrobial stewardship. This was further exacerbated by the lack of positive culture isolates from clinical specimens, which meant that patients were often continued on broader-spectrum empiric treatment.

A Qualitative Study Investigating the Barriers to the Implementation of the 'Sepsis Six Care Bundle' in Maternity Wards.

Background: In 2014, the Sepsis Six Care Bundle (SSCB) was introduced into a Scottish health region to improve patient outcomes. Poor compliance was demonstrated with the SSCB across different specialities. This study explored determinants of non-compliance with the SSCB in maternity wards. Methods: In-depth interviews were conducted with midwives in a single Scottish health region. Convenience sampling was used to recruit interviewees. The interviews were digitally recorded, transcribed verbatim, entered into NVivo software, and analysed using thematic analysis. Results: Thirteen face-to-face interviews were completed and lasted an average of 33 min. Three main barriers were identified to SSCB implementation; the difficulty of diagnosing sepsis, the suitability of the SSCB in a maternity setting as part of the pre-conditions phase, and the lack of staff training as part of the pre-implementation phase. Conclusion: The findings emphasize the importance of adapting improvement initiatives with sufficient preparation of staff in the rationale use to the context of care bundles.

Metabolism of two new benzodiazepine-type anti-leishmanial agents in rat hepatocytes and hepatic microsomes and their interaction with glutathione in macrophages.

OBJECTIVES: To measure the metabolism and toxicity of 7-chloro-4-(cyclohexylmethyl)-1-methyl-3,4-dihydro-1H-1,4-benzodiazepine-2,5-dione (BNZ-1) and 4-cyclohexylmethyl-1-methyl-3,4-dihydro-1H-1,4-benzodiazepine-2,5-dione (BNZ-2), two new benzodiazepine analogues found to be effective against Leishmania amastigotes in vitro. METHODS: The metabolism of BNZ-1 and -2 was investigated in isolated rat hepatocytes and rat liver microsomes. The toxicity of the compounds was assessed in a murine macrophage cell line by determining cell viability and reduced glutathione (GSH) content. The metabolism and toxicity of flurazepam was assessed for comparison. KEY FINDINGS: BNZ-1 and BNZ-2 underwent similar metabolic transformations by the liver systems, forming N-demethylated and hydroxylated metabolites, with subsequent O-glucuronidation. Flurazepam and both analogue compounds depleted macrophage GSH levels without affecting cell viability at the concentrations used (up to 100 microM), but only flurazepam inhibited glutathione reductase activity, indicating that it is acting by a different mechanism. CONCLUSIONS: The exact mechanism responsible for GSH depletion is unknown at present. Further experiments are needed to fully understand the effects of BNZs on the parasite GSH analogue, trypanothione, which may be a direct or indirect target for these agents. Pharmacokinetic evaluation of these compounds is required to further progress their development as potential new treatments for leishmaniasis.

Plasma Metabolomics Identifies Lipid and Amino Acid Markers of Weight Loss in Patients with Upper Gastrointestinal Cancer.

Cachexia is a multifactorial wasting syndrome associated with high morbidity and mortality in patients with cancer. Diagnosis can be difficult and, in the clinical situation, usually relies upon reported weight loss. The 'omics' technologies allow us the opportunity to study the end points of many biological processes. Among these, blood-based metabolomics is a promising method to investigate the pathophysiology of human cancer cachexia and identify candidate biomarkers. In this study, we performed liquid chromatography mass spectrometry (LC/MS)-based metabolomics to investigate the metabolic profile of cancer-associated weight loss. Non-selected patients undergoing surgery with curative intent for upper gastrointestinal cancer were recruited. Fasting plasma samples were taken at induction of anaesthesia. LC/MS analysis showed that 6 metabolites were highly discriminative of weight loss. Specifically, a combination profile of LysoPC 18.2, L-Proline, Hexadecanoic acid, Octadecanoic acid, Phenylalanine and LysoPC 16:1 showed close correlation for eight weight-losing samples (≥5% weight loss) and nine weight-stable samples (<5%weight loss) between predicted and actual weight change (r = 0.976, p = 0.0014). Overall, 40 metabolites were associated with ≥5% weight loss. This study provides biological validation of the consensus definition of cancer cachexia (Fearon et al.) and provides feasible candidate markers for further investigation in early diagnosis and the assessment of therapeutic intervention.

Probing polydopamine adhesion to protein and polymer films: microscopic and spectroscopic evaluation.

Polydopamine has been found to be a biocompatible polymer capable of supporting cell growth and attachment, and to have antibacterial and antifouling properties. Together with its ease of manufacture and application, it ought to make an ideal biomaterial and function well as a coating for implants. In this paper, atomic force microscope was used to measure the adhesive forces between polymer-, protein- or polydopamine-coated surfaces and a silicon nitride or polydopamine-functionalised probes. Surfaces were further characterised by contact angle goniometry, and solutions by circular dichroism. Polydopamine was further characterised with infrared spectroscopy and Raman spectroscopy. It was found that polydopamine functionalisation of the atomic force microscope probe significantly reduced adhesion to all tested surfaces. For example, adhesion to mica fell from 0.27 ± 0.7 to 0.05 ± 0.01 nN nm-1. The results suggest that polydopamine coatings are suitable to be used for a variety of biomedical applications.

Untargeted Metabolomics Profiling of an 80.5 km Simulated Treadmill Ultramarathon.

Metabolomic profiling of nine trained ultramarathon runners completing an 80.5 km self-paced treadmill-based time trial was carried out. Plasma samples were obtained from venous whole blood, collected at rest and on completion of the distance (post-80.5 km). The samples were analyzed by using high-resolution mass spectrometry in combination with both hydrophilic interaction (HILIC) and reversed phase (RP) chromatography. The extracted putatively identified features were modeled using Simca P 14.1 software (Umetrics, Umea, Sweden). A large number of amino acids decreased post-80.5 km and fatty acid metabolism was affected with an increase in the formation of medium-chain unsaturated and partially oxidized fatty acids and conjugates of fatty acids with carnitines. A possible explanation for the complex pattern of medium-chain and oxidized fatty acids formed is that the prolonged exercise provoked the proliferation of peroxisomes. The peroxisomes may provide a readily utilizable form of energy through formation of acetyl carnitine and other acyl carnitines for export to mitochondria in the muscles; and secondly may serve to regulate the levels of oxidized metabolites of long-chain fatty acids. This is the first study to provide evidence of the metabolic profile in response to prolonged ultramarathon running using an untargeted approach. The findings provide an insight to the effects of ultramarathon running on the metabolic specificities and alterations that may demonstrate cardio-protective effects.

In-vitro/in-vivo correlation of pulsatile drug release from press-coated tablet formulations: a pharmacoscintigraphic study in the beagle dog.

The aim of the current study was to investigate the in-vitro and in-vivo performance of a press-coated tablet (PCT) intended for time delayed drug release, consisting of a rapidly disintegrating theophylline core tablet, press-coated with barrier granules containing glyceryl behenate (GB) and low-substituted hydroxypropylcellulose (L-HPC). The PCTs showed pulsatile release with a lag time dependent upon the GB and L-HPC composition of the barrier layer. In-vivo gamma-scintigraphic studies were carried out for PCTs containing GB:L-HPC at 65:35 w/w and 75:25 w/w in the barrier layer in four beagle dogs, in either the fed or fasted state. The in-vivo lag time in both the fed and fasted states did not differ significantly (p>0.05) from the in-vitro lag time. Additionally, no significant difference (p<0.05) between in-vivo fed and fasted disintegration times was observed, demonstrating that in-vivo performance of the PCT was not influenced by the presence or absence of food in the gastrointestinal tract. A distinct lag time was obtained prior to the appearance of drug in plasma and correlated (R2=0.98) with disintegration time observed from scintigraphic images. However, following disintegration, no difference in pharmacokinetic parameters (AUC(0-6 dis), K(el), Cmax) was observed. The current study highlighted the potential use of these formulations for chronopharmaceutical drug delivery.

Comparison of the physical characteristics of monodisperse non-ionic surfactant vesicles (NISV) prepared using different manufacturing methods.

Non-ionic surfactant vesicles (NISV) are synthetic membrane vesicles formed by self-assembly of a non-ionic surfactant, often in a mixture with cholesterol and a charged chemical species. Different methods can be used to manufacture NISV, with the majority of these requiring bulk mixing of two phases. This mixing process is time-consuming and leads to the preparation of large and highly dispersed vesicles, which affects the consistency of the final product and could hinder subsequent regulatory approval. In this study, we have compared the physical characteristics of NISV prepared using two conventional methods (thin-film hydration method and heating method) with a recently introduced microfluidic method. The resulting particles from these methods were assessed for their physical characteristics and in vitro cytotoxicity. Through microfluidics, nano-sized NISV were prepared in seconds, through rapid and controlled mixing of two miscible phases (lipids dissolved in alcohol and an aqueous medium) in a microchannel, without the need of a size reduction step, as required for the conventional methods. Stability studies over two months showed the particles were stable regardless of the method of preparation and there were no differences in terms of EC50 on A375 and A2780 cell lines. However, this work demonstrates the flexibility and ease of applying lab-on-chip microfluidics for the preparation of NISV that could be used to significantly improve formulation research and development, by enabling the rapid manufacture of a consistent end-product, under controlled conditions.