Real time microcalorimetric profiling of prebiotic inulin metabolism

The in vitro assessment of prebiotics involves elaborate microbiological techniques or a combination of culture techniques and molecular methods. In this study, the isothermal microcalorimeter, an instrument which can monitor the real time growth of bacteria was applied to investigate the prebiotic effect of inulin in real time. Fresh and standardized frozen faecal slurries were prepared, placed and monitored in the isothermal microcalorimeter. The faecal samples and commercial probiotic strains Lactobacillus acidophilus LA-5®, Bifidobacterium lactis BB-12® were cultured in a mixed medium of cooked meat medium (CMM) and brain heart infusion (BHI) broth with and without supplementation with inulin and monitored in the microcalorimeter. The results showed power-time (p-t) curves that were characteristic for the samples. The p-t curves of the fresh and frozen faecal samples were similar. Augmented microbial activity was observed when the faecal sample was inoculated into CMM-BHI mixed broth with significant enhancement of microbial activity detected in the presence of inulin which was reproducible. Deconvoluted p-t curves showed multiple peaks with time and intensity variance depending on presence or absence of inulin suggesting possible differences in utilization of inulin by the different groups of bacteria in the polymicrobial sample. P-t curves of the pure species did not show any significant change when inulin was supplemented into the medium likely due to the inability of the bacteria to primarily utilize inulin

Ciprofloxacin-loaded electrospun nanofibres for antibacterial wound dressings

A wound is an injury that damages the normal structure and function of the skin and the underlying tissue. Disruption of the wound healing process causes chronic wounds, which are usually associated with microbial infections. In this work, ciprofloxacin was loaded into electrospun nanofibres to generate antibacterial wound dressings. Electrospun nanofibres are suitable for wound dressings due to their adaptability to the wound contour, high porosity for gas exchange, and a high surface area for absorbing wound exudate. Ciprofloxacin was successfully incorporated in polyvinyl alcohol (PVA) and PVA/alginate-blended electrospun nanofibres, with mean diameters ranging from 258 to 460 nm. The materials were characterized using differential scanning calorimetry (DSC) and X-ray diffraction (XRD) to examine the thermal properties and physical form of the drug and polymers. Fourier transform infrared spectroscopy (FTIR) was used to characterise intermolecular interactions within the materials. DSC thermograms showed all the fibres have a PVA enthalpy relaxation peak at 47 °C and a PVA melting endotherm at 229 °C. The XRD patterns indicated decreased crystallinity of PVA after electrospinning. No crystalline drug could be detected in the fibres by either XRD or DSC. FTIR spectra showed the formation of hydrogen bonds between PVA and alginate in the fibres. All the electrospun nanofibres have high water uptake capacity (190%–381%). The ciprofloxacin-loaded electrospun nanofibres also have high drug encapsulation efficiency, above 90%. The drug release profiles demonstrated controlled-release of the drug, following the Korsmeyer-Peppas model. The antibacterial efficacy of the nanofibres was evaluated by isothermal microcalorimetric assays, with the ciprofloxacin-loaded nanofibres found to exhibit equivalent antibacterial efficacy against Staphylococcus aureus and Pseudomonas aeruginosa to pure ciprofloxacin. Hence, the fibres fabricated in this work have the potential to be used as advanced systems to prevent infection during wound healing

The potential for isothermal microcalorimetry to detect venous catheter infection isolates and establish antibiograms

OBJECTIVES: Because bloodstream infection and venous catheter (or cannula) bloodstream infection are associated with high morbidity and cost, early identification and treatment are important. Isothermal microcalorimetry can detect microbial growth using thermal power (heat flow), essentially in real time. The aim of this study was to examine the potential of this technique in clinical practice. METHODS: Thermal power of wild-type bacteria (Escherichia coli, Staphylococcus epidermidis, Klebsiella pneumoniae, and Enterococcus faecium) isolated from blood cultures of adult inpatients receiving parenteral nutrition in routine clinical practice was measured at 37°C every 10s using a Thermometric 2277 instrument. Temporal patterns of heat flow were used to detect the presence of bacteria, differentiate between them, and test their antibiotic sensitivity. Within and between batch reproducibility (% coefficient of variation [%CV]) was also established. RESULTS: Isothermal microcalorimetry always correctly detected the absence or presence of wild-type bacteria. Thermograms differed distinctly between species. Key thermographic features, such as peak heights, timing of peak heights, and interval between peak heights, were highly reproducible within each species (within-batch %CV usually about ≤1%, although between-batch %CV was usually higher). The antibiotic sensitivities (tested only for S. epidermidis and K. pneumoniae) confirmed the results obtained from the hospital laboratory. CONCLUSIONS: Isothermal microcalorimetry is a promising and highly reproducible real-time measurement technique with potential application to the investigation, species identification, and targeted antibiotic treatment of bloodstream infection and venous catheter (or cannula) bloodstream infection

The Role of Artificial Intelligence in Generating Original Scientific Research

Artificial intelligence (AI) is a revolutionary technology that is finding wide application across numerous sectors. Large language models (LLMs) are an emerging subset technology of AI and have been developed to communicate using human languages. At their core, LLMs are trained with vast amounts of information extracted from the internet, including text and images. Their ability to create human-like, expert text in almost any subject means they are increasingly being used as an aid to presentation, particularly in scientific writing. However, we wondered whether LLMs could go further, generating original scientific research and preparing the results for publication. We taskedGPT-4, an LLM, to write an original pharmaceutics manuscript, on a topic that is itself novel. It was able to conceive a research hypothesis, define an experimental protocol, produce photo-realistic images of printlets, generate believable analytical data from a range of instruments and write a convincing publication-ready manuscript with evidence of critical interpretation. The model achieved all this is less than 1h. Moreover, the generated data were multi-modal in nature, including thermal analyses, vibrational spectroscopy and dissolution testing, demonstrating multi-disciplinary expertise in the LLM. One area in which the model failed, however, was in referencing to the literature. Since the generated experimental results appeared believable though, we suggest that LLMs could certainly play a role in scientific research but with human input, interpretation and data validation. We discuss the potential benefits and current bottlenecks for realising this ambition here

Assessing gastric viability of probiotics: real testing in real human gastric fluid

Background: It is believed that the harsh conditions of the upper gastrointestinal tract, such as gastric fluid acidity, may affect the viability of ingested probiotics. Thus far, this notion has been verified in vitro by viability testing in simulated gastric fluid. // Objective: In this study, the survival of 8 probiotic bacteria was investigated in real human gastric fluid to determine the response of the bacteria in the actual biological medium. // Methods: Gastric tolerance of the different probiotic bacteria was determined by inoculation of the bacteria in human gastric fluid, sampling at 30 min, 60 min, 120 min, 180 min, serial dilution and spread plating. Tolerance was also determined in traditionally simulated fluids at pH of 2.2 ± 0.1 and 2.8 ± 0.1, mimicking the pH of the human gastric fluid. // Results: All the probiotic bacteria tested except for one strain, which showed less than 1 log CFU/mL loss in viability in the two fluids, were susceptible to the gastric fluids. The results showed significant (p 0.05) and hence provided a comparable environment to the actual human fluid at a similar pH. // Conclusion: More than 80% of the tested probiotic strains were susceptible to real human gastric fluids. The results demonstrated strain differences in the susceptibility of different probiotic bacteria to gastric fluid. Also noteworthy are the differences in the behaviour of some of the probiotic bacteria in the real fluid against the simulated fluid. The result highlights the importance of using biorelevant test systems in viability assays

Simultaneous differential scanning calorimetry – synchrotron X-ray powder diffraction : a powerful technique for physical form characterisation in pharmaceutical materials

© 2016 American Chemical Society. We report a powerful new technique: hyphenating synchrotron X-ray powder diffraction (XRD) with differential scanning calorimetry (DSC). This is achieved with a simple modification to a standard laboratory DSC instrument, in contrast to previous reports which have involved extensive and complex modifications to a DSC to mount it in the synchrotron beam. The high-energy X-rays of the synchrotron permit the recording of powder diffraction patterns in as little as 2 s, meaning that thermally induced phase changes can be accurately quantified and additional insight on the nature of phase transitions obtained. Such detailed knowledge cannot be gained from existing laboratory XRD instruments, since much longer collection times are required. We demonstrate the power of our approach with two model systems, glutaric acid and sulfathiazole, both of which show enantiotropic polymorphism. The phase transformations between the low and high temperature polymorphs are revealed to be direct solid-solid processes, and sequential refinement against the diffraction patterns obtained permits phase fractions at each temperature to be calculated and unit cell parameters to be accurately quantified as a function of temperature. The combination of XRD and DSC has further allowed us to identify mixtures of phases which appeared phase-pure by DSC

Crystallisation in printed droplets: understanding crystallisation of d-mannitol polymorphs

Crystallisation of mannitol in the confinement of inkjet printed droplets was studied; the effects of droplet size and the presence of a foreign surface were investigated in comparison to the commonly used manufacturing technique of spray drying. Only the metastable polymorphs (α and δ) were observed in printed droplets with predominance of the α polymorph with increasing the droplet size, except for the smallest droplets generated (�100 pL) where the stable β polymorph was observed. The β polymorph was also predominant in spray-dried samples, with metastable forms appearing upon the addition of a polymer (Eudragit). We propose a dependence of the crystallisation of mannitol polymorphs on either the presence or absence of a surface to favour either the stable or the metastable polymorphs. These findings expand the experimental work that could be conducted to understand the crystallisation behaviour in droplets. By proposing heterogeneous nucleation to favour the formation of the metastable polymorphs while homogeneous nucleation favouring the stable β polymorph, one might understand why the same manufacturing method such as spray drying would produce one polymorph when processed alone but another when present in a formulation. This is of great importance to the pharmaceutical industry to aid in understanding the implications of crystallisation in manufacturing processes such as spray drying

Damage limitation: comparing the impact of polymers on bleached hair, when applied within or as post-bleach treatments

Hair bleaching causes undesirable chemical and structural changes to the cortex, the most prominent process being the oxidation of the disulphide bonds of the amino acid cystine and the creation of cysteic acid. It is known that this process affects mostly the Keratin Associated Proteins (KAP) which are amorphous and sulphur-rich. A major secondary effect is the overall destabilisation of the cortex structure within which the crystalline Intermediate Filaments’ (IF) proteins are supported by KAP. An overall decrease in the proportion of ordered protein structure, reduction of mechanical strength and the denaturation temperature of hair have been used to quantify the degree of damage. The cuticle also undergoes oxidative damage during bleaching which causes reduced thickness and increased surface roughness. Mitigating and counteracting these changes in the hair surface and internal structure have been a prime objective of the haircare industry. Such action would be expected to deliver immediate sensory benefits perceivable by the consumer. This project was to compared the impact of three actives said to deliver structural benefits to bleached hair. Their impact was evaluated in two conditions: when applied with the bleaching cream (WB) and after bleaching (AT)

Virtually Possible: Enhancing Quality Control of 3D-Printed Medicines with Machine Vision Trained on Photorealistic Images

Three-dimensional (3D) printing is an advanced pharmaceutical manufacturing technology, and concerted efforts are underway to establish its applicability to various industries. However, for any technology to achieve widespread adoption, robustness and reliability are critical factors. Machine vision (MV), a subset of artificial intelligence (AI), has emerged as a powerful tool to replace human inspection with unprecedented speed and accuracy. Previous studies have demonstrated the potential of MV in pharmaceutical processes. However, training models using real images proves to be both costly and time consuming. In this study, we present an alternative approach, where synthetic images were used to train models to classify the quality of dosage forms. We generated 200 photorealistic virtual images that replicated 3D-printed dosage forms, where seven machine learning techniques (MLTs) were used to perform image classification. By exploring various MV pipelines, including image resizing and transformation, we achieved remarkable classification accuracies of 80.8%, 74.3%, and 75.5% for capsules, tablets, and films, respectively, for classifying stereolithography (SLA)-printed dosage forms. Additionally, we subjected the MLTs to rigorous stress tests, evaluating their scalability to classify over 3000 images and their ability to handle irrelevant images, where accuracies of 66.5% (capsules), 72.0% (tablets), and 70.9% (films) were obtained. Moreover, model confidence was also measured, and Brier scores ranged from 0.20 to 0.40. Our results demonstrate promising proof of concept that virtual images exhibit great potential for image classification of SLA-printed dosage forms. By using photorealistic virtual images, which are faster and cheaper to generate, we pave the way for accelerated, reliable, and sustainable AI model development to enhance the quality control of 3D-printed medicines