9 research outputs found

    Needle-free drug delivery using shock wave techniques

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    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006."June 2006."Includes bibliographical references (leaves 93-94).A recent advancement in the area of needle-free injection systems has been the development of devices capable of epidermal delivery of powder medications. These devices use high-pressure compressed gas to accelerate drug particles 2 to 50 gpm in size to velocities of 200 to 1000 m/s. At these speeds the particles have sufficient momentum to penetrate the skin barrier and reach the viable epidermal layers. The devices offer much better control over the depth of penetration than traditional hypodermic needles, a factor particularly important in vaccine delivery. However they still have not found wide spread use, because of their cost. We studied the parameters determining the performance of these devices and used that knowledge to create a simple and reusable device capable of delivering 3 to 10 mg of powder formulation to the viable epidermis. Furthermore we showed that hydrogen-oxygen combustion could be used to create the shock wave required to accelerate the drug particles. This proves that portable reusable devices powered by hydrogen can be constructed and used for vaccine and medication delivery.by Atanas Pavlov.S.M

    Recent Progress in Amaryllidaceae Biotechnology

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    Plants belonging to the monocotyledonous Amaryllidaceae family include about 1100 species divided among 75 genera. They are well known as medicinal and ornamental plants, producing pharmaceutically important alkaloids, the most intensively investigated of which are galanthamine and lycorine. Amaryllidaceae alkaloids possess various biological activities, the most important one being their anti-acetylcholinesterase activity, used for the treatment of Alzheimer’s disease. Due to increased demand for Amaryllidaceae alkaloids (mainly galanthamine) and the limited availability of plant sources, in vitro culture technology has attracted the attention of researchers as a prospective alternative for their sustainable production. Plant in vitro systems have been extensively used for continuous, sustainable, and economically viable production of bioactive plant secondary metabolites. Over the past two decades, a significant success has been demonstrated in the development of in vitro systems synthesizing Amaryllidaceae alkaloids. The present review discusses the state of the art of in vitro Amaryllidaceae alkaloids production, summarizing recently documented plant in vitro systems producing them, as well as the authors’ point of view on the development of biotechnological production processes with a focus on the future prospects of in vitro culture technology for the commercial production of these valuable alkaloids

    Cultivation of diploid and tetraploid hairy roots of Datura stramonium L. in stirred tank bioreactor for tropane alkaloids production

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    Biomass accumulation and tropane alkaloids production by diploid and tetraploid hairy root cultures of Datura stramonium L. cultivated in stirred tank bioreactor at different aeration rates were investigated. The maximal growth for both hairy root cultures (ADB = 8.3 g/L and 6.8 g/L for diploid and tetraploid line, respectively) was achieved at aeration rate of 15.0 L/(L.h). The corresponding growth indexes were remarkably high (GIDW = 9.0 and 7.8 for diploid and tetraploid line, respectively) compared to the values, usually reported for other hairy root cultures. The optimal aeration rate for biomass accumulation was also optimal for alkaloids biosynthesis. According to our survey, the achieved maximal amounts of accumulated hyoscyamine (35.0 mg/L and 27.0 mg/L for diploid and tetraploid line) were the highest reported in the scientific literature for D. stramonium L. hairy roots. During the cultivation in stirred tank bioreactor, the hairy roots biosynthesized pharmaceutically important alkaloid scopolamine in minor concentrations. This is an important observation since scopolamine was not detected during submerged cultivation of these hairy root lines in other bioreactor types. However, the ploidy level was found to be the most important factor concerning scopolamine production by D. stramonium L. hairy roots cultures. The present work demonstrated the effect of ploidity levels on biomass accumulation and tropane alkaloids production by D. stramonium L. hairy roots cultivated in stirred tank bioreactor. This investigation show that the stirred tank bioreactor could be successfully applied for both maximal biomass accumulations, as well as for manipulation of tropane alkaloids production by diploid and tetraploid D. stramonium L. hairy root cultures

    Triterpenoids and Other Non-Polar Compounds in Leaves of Wild and Cultivated Vaccinium Species

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    The purpose of the current study was to identify and quantify triterpenoids and other non-polar compounds in the leaves of three high bush blueberry cultivars (Vaccinium corymbosum L. var. Bluegold, var. Bluecrop and var. Elliott) and three natural populations of Vaccinium species (Vaccinium uliginosum L., Vaccinium myrtillus L. and Vaccinium vitis-idaea L.) by means of gas chromatography mass spectrometry (GC-MS) and high-performance liquid chromatography with diode array detector (HPLC-DAD). Metabolite profiles differed significantly among the Vaccinium species analyzed, as well as among the populations of the same species. The populations of V. vitis-idaea predominantly contained relative concentrations of phytosterols (varying between 10.48% of total ion current (TIC) and 22.29% of TIC) and almost twice the content of triterpenes (from 29.84% of TIC to 49.62% of TIC) of the other berry species investigated. The leaves of V. corymbosum varieties biosynthesized the highest relative amount of fatty acids, while the leaves of the populations of V. uliginosum had the highest relative concentrations of fatty alcohols. The results of principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed that the diverse populations of each berry species analyzed differed from each other, most likely due to variations in the climatic and geographical conditions of their localities

    Antioxidant activity and fructan content in root extracts from elecampane (Inula helenium L.)

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    The purpose of the present study was to investigate the antioxidant activity and fructans content in ethanol and water extracts of roots of elecampane (Inula helenium L.), a Bulgarian medicinal plant. The extraction procedure included 95% (v/v) ethanol extraction and subsequent water treatment. The antioxidant activity was evaluated by several reliable methods such as DPPH-, ABTS-, FRAP- and CUPRAC-assays, as well as the total phenolic content. In addition, the total fructans and sugar content were determinated by spectrophotomeric, TLC and HPLC-RID methods. The level of fructans in ethanol extracts was 14.1 g / 100 g dry weight, as nystose and 1-kestose were only 0.3 g / 100 g dry weight, and 0.5 g / 100g dry weight, respectively. The absence of fructooligosacharides and sugars in water extracts after the ethanol pretreatment was established. Inulin content was evaluated to be 32 g / 100 g dry weight. The metabolites profile of roots revealed their potential application as radical scavengers due to the presence of polyphenols. Therefore, the root extracts of elecampane could be assumed as a rich source of biologically active substance, in particular dietary fiber with potential prebiotic effect, due to the presence of polysaccharide inulin and fructooligosacharides

    Acetylcholinesterase inhibitory, antioxidant, and antimicrobial activities of Salvia tomentosa Mill. essential oil

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    Chemical composition and bioactivity of essential oil from Salvia tomentosa Mill. natively grown in Bulgaria were investigated. GC-MS analysis identified 60 compounds which represented 98% of the oil constituents. The prevalent constituents were monoterpenes with eight dominant compounds being identified: borneol (10.3%), β-pinene (9%), camphor (7.9%), α-pinene (6%), camphene (4%), 1.8-cineole (3.8%), α-limonene (3.5%) and β-caryophyllene (3%). The essential oil showed considerable acetylcholinesterase inhibitory activity (IC50=0.28±0.06 µg/mL), comparable with that of galanthamine. Study of antioxidant activity strongly suggested that the hydrogen atom transfer reaction was preferable over the electron transfer (ORAC=175.0±0.40 µM Trolox equivalents/g oil and FRAP=1.45±0.21 mM Trolox equivalents/g oil). The essential oil showed moderate antifungal and antibacterial activities against Candida albicans and Gram-positive bacteria, whereas it was almost inactive against the investigated Gram-negative strains. The results suggested that the essential oil of Bulgarian S. tomentosa could be considered as a prospective active ingredient for prevention of oxidative stress-related and neurodegenerative disorders in aromatherapy. Because of the high antioxidant capacity, the oil could be considered as natural supplement or antioxidant in cosmetics and food products
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