Synthetic Seeds Vis-A-Vis Cryopreservation: An Efficient Technique for Long-Term Preservation of Endangered Medicinal Plants
Amit Baran Sharangi, K. V. Peter in Medicinal Plants, 2023
Synthetic seed may be either hydrated or desiccated in nature. The first hydrated synthetic seed was developed by Redenbaugh et al. (1984) for alfalfa and celery while desiccated synthetic seed was developed by Kitto and Janick (1985) for carrot (Ara et al., 2000). The hydrated artificial seeds are made up of encapsulating plant materials in hydrogel coats while the desiccated seeds are either naked or encapsulated in polyoxyethylene glycol followed by its desiccation (Kikowska and Thiem, 2011). Desiccation may be done either slowly over a period of one or two weeks sequentially decreasing relative humidity or rapidly by unsealing the petri dishes and leaving them on the bench overnight to dry under airflow. These types of synthetic seeds are prepared for desiccation tolerance while encapsulated seeds are produced for desiccation susceptible plants (Ara et al., 2000).
Fiber optic-based radiochromic dosimetry
Sam Beddar, Luc Beaulieu in Scintillation Dosimetry, 2018
Small variations in humidity, typical of normal operations, are unlikely to affect the radiochromic sensitive layer within the sealed system of the fiber-optic probe, although this has not been explicitly tested. What has a higher probability of affecting the quality of the dosimeter is the final hydration of the sensitive layer achieved during manufacturing. It has been illustrated that water plays an important role in how the monomers arrange themselves within the three-dimensional crystal of LiPCDA (Rink et al. 2008). Desiccating the sensitive layer resulted in both a shift in main spectral peak to higher wavelengths and a decrease in netOD of nearly (for a 3 Gy dose). Reintroducing water into the sensitive layer by exposing it to moisture resulted in another shift in spectrum, this time with main absorbance peak moving to lower wavelengths, but not quite to the original . Although desiccation has drastic effects both on spectral properties and on sensitivity of LiPCDA, it requires effort to achieve this. The results described above were typical for desiccation over calcium chloride in a oven for or more. Therefore, while an important issue to consider for manufacturing purposes, humidity fluctuations are not likely to be an issue for the end user.
Electrosurgical Principles In Gastrointestinal Endoscopy
John P. Papp in Endoscopie Control of Gastrointestinal Hemorrhage, 2019
Most “coagulation” in general surgery is done with fulguration. If sparks occur and it did not cut, the mode was fulguration. In contrast, pure desiccation is routinely used only in opthalmology, neurosurgery, and in laparoscopic sterilization procedures. Fulguration has several advantages over desiccation. The electrode does not have to have contact with tissue while fulgurating.Because the fulguration process is not limited to the temperature of boiling water, the tissue can be pyrolyzed to a tough strong eschar.High quality fulguration can penetrate a swiftly moving layer of blood to stop brisk arterial bleeders up to 1.5 mm in diameter.Fulguration has the potential to provide better hemostasis for most applications with less depth of penetration than desiccation.
Therapeutic advances in wound healing
Published in Journal of Dermatological Treatment, 2022
André Oliveira, Sandra Simões, Andreia Ascenso, Catarina Pinto Reis
CDOT usually consists of devices that provide a continuous oxygen supply to the wound site. As opposed to HBOT and THOT, these devices are portable and deliver oxygen at normospheric pressure and slower flow rates directly to the wound bed that must be covered with a moist wound dressing to allow oxygen diffusion. In fact, without humidification, desiccation can occur preventing oxygen solubilization in the wound fluid, and consequently, reducing its transport into the tissue. Although THOT uses high flow rates (40 L/min) which can cause desiccation, these devices provide intermittent therapy (90 min/day, five days a week), and thus not require a moist environment. It has fewer reported risks and side effects than previous modalities and offers easy therapeutic delivery (152). Despite that studies regarding this new class of devices are limited, some have shown THOT could be beneficial in the healing of DFUs, sickle cell disease ulcers as well as in the treatment of recalcitrant and painful wounds as an adjunct (159–162).
Polysaccharide nanoparticles for oral controlled drug delivery: the role of drug–polymer and interpolymer interactions
Published in Expert Opinion on Drug Delivery, 2020
Annalisa Bianchera, Ruggero Bettini
Lyophilization is the preferred technique to dry NPs, especially when heat-sensitive APIs, such as proteins, are included in the formulation: the major concern when dealing with protein freeze-drying is the prevention of stress, that often requires the addition of protectants. The choice of cryoprotectant depends on the type of polymer involved in the formation of NPs [80]. For example, Almalik et al. [81] evaluated the effect of different cryoprotectants on chitosan NPs coated with hyaluronic acid or alginate, finding that trehalose and sucrose gave the best results in terms of maintenance of particle size and prevention of aggregation; this was confirmed for the freeze drying of protein-based NPs [82,83]. The effect of freeze-drying on particle characteristics is commonly compared to the effect given by spray-drying, as described by Rampino et al. [84] who selected trehalose as the best cryoprotectant for both techniques. Also, Cerchiara et al. [85] compared freeze-dried and spray-dried nanoparticles prepared from chitosan/TPP for colon-specific delivery of vancomycin. Micro- and nanoparticles were produced by the two techniques, resulting in different release profile of the antibiotic glycopeptide: the nanoformulation obtained by spray drying showed the best profile in terms of drug release and antimicrobial activity in vitro. Lyophilization can have denaturizing effects on pharmaceuticals; moreover, resulting cakes need a secondary procedure to obtain fine particles. This step can be avoided if desiccation is performed by spray drying [86] or spray congealing.
Understanding the compaction behaviour of low-substituted HPC: macro, micro, and nano-metric evaluations
Published in Pharmaceutical Development and Technology, 2018
Amr ElShaer, Ali Al-khattawi, Afzal R. Mohammed, Monika Warzecha, Dimitrios A. Lamprou, Hany Hassanin
In order to evaluate the compressibility and tabletability of L-HPC powders, 500 mg of the powders were accurately weighted out and directly compressed. The powders were directly compressed using a uniaxial hydraulic press (Specac Tablet Presser, Kent, UK) and 13 mm split, in order to prevent mechanical failure the decompression process was controlled using. Powders were compressed at compression pressures 74, 148, 22, 295, and 443 MPa, with a dwell time of 30 s. Cylindrical tablets with diameter of ∼13 mm and flat faced surface were obtained. A desiccator containing silicon dioxide was used to maintain relative humidity under 4% (Ebro Data logger, EBI 20-IF, Ingolstadt, Germany), L-HPC powders and tablets were stored under desiccation for at least 48 h and at 25 °C prior to use.
Related Knowledge Centers
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