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Green Metal-Based Nanoparticles Synthesized Using Medicinal Plants and Plant Phytochemicals against Multidrug-Resistant Staphylococcus aureus
Published in Richard L. K. Glover, Daniel Nyanganyura, Rofhiwa Bridget Mulaudzi, Maluta Steven Mufamadi, Green Synthesis in Nanomedicine and Human Health, 2021
Abeer Ahmed Qaed Ahmed, Lin Xiao, Tracey Jill Morton McKay, Guang Yang
The preparation of plant extract is the first step in green synthesis of NPs (Fig. 10.1). The whole plant or parts of the plants should be collected from the designated area and thoroughly washed (several times) with tap water to remove all visible dirt, soil and dead tissue. Plant materials must then be washed with sterile distilled water. Further shade or sunlight drying for up to 20 days is required (Abbasi et al., 2020). Alternatively, several hours of oven drying at high temperatures are also required (Suresh et al., 2018). The dry plant materials should be powdered using a blender. Store plant powder in a dry airtight container until needed. Plant extract is prepared as required. For instance, if aqueous extract is needed, dried plant powder (around 1–10 g) can be boiled with a suitable volume of deionized distilled water (20–100 ml) at 70°C for 10 minutes. The obtained infusion is then filtered with Whatman filter paper until all insoluble materials are removed. The filtrate can be stored at 4°C until required (Ahmad et al., 2016; Iqbal et al., 2020). Other plant extracts such as ethyl acetate, chloroform, methanol and hexane extracts are prepared according to the literature (Manubolu et al., 2013; Elango and Roopan, 2015).
The administration of medicines to children
Published in Evelyne Jacqz-Aigrain, Imti Choonara, Paediatric Clinical Pharmacology, 2021
Evelyne Jacqz-Aigrain, Imti Choonara
Capsules are hard gelatin shells which can be filled with powder manually or semi-automatically. Because of difficulty with swallowing capsules, for many younger children, they are simply used as containers for powder since the capsules are often opened before administration and the contents given with liquid or food. Powders can also be individually weighed and presented in powder papers or individual containers of plastic or glass. The powder is administered in liquid or food. In general, if stored under suitable conditions away from moisture, oral capsules and powders should have greater stability than oral liquids but are more time consuming to prepare. They are fixed dosage forms so many different strengths may be required to satisfy the varying dosage requirement of children of different ages.
HLA-DR and -DQ Serotyping
Published in M. Kam, Jeffrey L. Bidwell, Handbook of HLA TYPING TECHNIQUES, 2020
For cell preparations in which the B cells have been labeled with FITC-anti-immunoglobulin, ethidium bromide solution is added. Ethidium bromide is carcinogenic and appropriate precautions should be taken when handling powder and solutions. The stock solution consists of ethidium bromide, 100 μg/ml in PBS. Make 100 ml of stock solution; this should be kept in the dark at 4°C. To prepare the working solution, take 0.3 ml of stock and add 20 ml of PBS/5% EDTA. The working solution can be aliquoted into 1 or 0.5 ml amounts and kept frozen until needed. Add 0.5 μl of solution to each well. The plates are read using an inverted epifluorescence microscope in a darkened room. With this method it is possible to estimate both B and T cell death. Under fluorescence, live B cells have a green cap and dead B cells are red with a green cap; live T cells are only visible if the plate is viewed with normal light and dead T cells are red without a cap.
A consensus research agenda for optimising nasal drug delivery
Published in Expert Opinion on Drug Delivery, 2020
Ben Forbes, Rene Bommer, Jonathan Goole, Marie Hellfritzsch, Wilbur De Kruijf, Pierre Lambert, Grazia Caivano, Alain Regard, Francesca Schiaretti, Marie Trenkel, Laurent Vecellio, Gerallt Williams, Fabio Sonvico, Regina Scherließ
A variety of devices and formulations are well established for nasal delivery (reviewed elsewhere; see [7–10]). Liquid formulations dominate the market and are delivered as drops, pump or propellant-driven sprays, or by nebulization. Powders are generally delivered by devices that spray the powder or require insufflation by the patient. Spray characteristics, deposition, mucociliary clearance, dissolution and absorption strongly affect the performance of nasal drug delivery systems. All of these steps can be influenced by formulation and device design. While the formulation is often key to performance, the device supports an optimized formulation and these components should not be considered in isolation. In principle, products for nasal drug delivery should be as simple as possible to reduce failure modes, but there are scenarios where high technology concepts may offer advantages, e.g. absorption enhancement in systemic delivery, targeted deposition in nose-to-brain delivery and adjuvants for nasal vaccination. The ideal attributes of a nasal spray are efficient deposition in the nasal cavity, reproducibility, robustness, tolerability and low respirable fraction [11–13]. The dependence of nasal deposition on aspects of the spray plume is poorly defined as it is technically difficult to vary properties such as droplet size distribution, droplet velocity and spray cone angle systematically and human factors are also a big influence.
Utility of extracellular matrix powders in tissue engineering
Published in Organogenesis, 2018
Lauren Edgar, Afnan Altamimi, Marta García Sánchez, Riccardo Tamburrinia, Amish Asthana, Carlo Gazia, Giuseppe Orlando
Despite biological composition, ECM powder can induce different changes in vivo depending on particle conformation. Specifically, size and morphology of ECM particles can influence cell proliferation, differentiation, tissue development.13,15,16 ECM powder has a wide distribution in particle size that is difficult to control.17 During powder preparation, residual moisture can induce clumping and agglomeration of powder can occur resulting in particles with numerous sizes. Separating agglomerations is difficult and clumps can be trapped in the milling process.18 Although particles with diverse shape and size are satisfactory substrates for cellular adhesion and growth,19 particles with uniform morphology allow for more control of tissue development in vivo. For example, use of powder with diverse particle sizes in skin TE diversity can manifest meshes with gaps which result in non-contiguous tissue formation that is cosmetically unaesthetic.17 Further study is needed to determine whether bioengineering of certain tissues may require specific particle sizes.
Pulmonary delivery of influenza vaccine formulations in cotton rats: site of deposition plays a minor role in the protective efficacy against clinical isolate of H1N1pdm virus
Published in Drug Delivery, 2018
Yoshita Bhide, Jasmine Tomar, Wei Dong, Jacqueline de Vries-Idema, Henderik W. Frijlink, Anke Huckriede, Wouter L. J. Hinrichs
Labeled or unlabeled WIV was spray freeze dried together with inulin (4 kDa, Sensus, Roosendaal, The Netherlands) as lyoprotectant. Inulin powders were prepared (from inulin solution in water) without influenza vaccine using the similar procedure. Briefly, labeled and unlabeled vaccine solutions were prepared in an HA: inulin weight ratio of 1:200 and 1:40, respectively. The HA: inulin weight ratios of 1:200 and 1:40 were based on a dose of 5 µg (deposition study) and 25 µg HA (immunogenicity study) in 1 mg of SFD powder. The vaccine solutions were sprayed into a vessel of liquid nitrogen using the two-fluid nozzle of the Buchi 190 Mini Spray Dryer with an inner diameter of 0.5 mm. The nozzle was placed approximately 5 cm above the level of liquid nitrogen. A liquid flow rate of 5 mL/min and an atomizing airflow of 600 Ln/h were used. Then, the frozen vaccine solutions were freeze dried for 48 h under the following conditions: during the first 24 h the shelf temperature was set at −35 °C and the pressure at 0.220 mbar, after which the, temperature was gradually increased to 20 °C and the pressure was lowered to 0.05 mbar during the next 24 h. The spray freeze dried vaccine formulations were collected in a chamber with a relative humidity ≤1% and ambient temperature. Until further use, the obtained powders were stored under airtight conditions.