• 공업화학
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• 제17권1호
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• pp.52-57
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• 2006

천연 항진균 물질인 황련(Coptidis Rhizoma)은 감염성 피부염을 유발시키는 주 원인균인 Cadida albicans에 항세균 작용이 있다고 알려져 있다. 본 연구에서는 황련유래 단백질(Proteins derived from Coptidis Rhizoma, CRP)의 유효 성분을 추출하여 안정성 도모 및 피부 세포 내에 안정하게 흡수시키는 물질 전달체로서 리포좀을 제조하였다. 황련유래 단백질을 함유한 리포좀 입자의 평균 크기는 187 nm, 표면전하는 3.337 mV이며 포집효율은 33%이었다. 온도, 저장시간에 따른 CRP의 방출 거동을 확인하였으며, 리포좀의 안정성을 증가시키기 위하여 리포좀을 poly(vinyl alcohol) (PVA)로 코팅하였다. 코팅된 리포좀은 코팅 안된 리포좀에 비하여 낮은 방출율을 나타내었다. 또한, 리포좀에 함유된 CRP의 항캔디다 효과는 $50^{\circ}C$ 또는 자외선(UV)으로 24 h 처리한 후에도 지속됨을 확인하였다.

• 생체재료학회지
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• 제22권4호
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• pp.328-336
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• 2018

Background: Biogenic fabrication of silver nanoparticles from naturally occurring biomaterials provides an alternative, eco-friendly and cost-effective means of obtaining nanoparticles. It is a favourite pursuit of all scientists and has gained popularity because it prevents the environment from pollution. Our main objective to take up this project is to fabricate silver nanoparticles from lichen, Usnea longissima and explore their properties. In the present study, we report a benign method of biosynthesis of silver nanoparticles from aqueous-ethanolic extract of Usnea longissima and their characterization by ultraviolet-visible (UV-vis), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses. Silver nanoparticles thus obtained were tested for antimicrobial activity against gram positive bacteria and gram negative bacteria. Results: Formation of silver nanoparticles was confirmed by the appearance of an absorption band at 400 nm in the UV-vis spectrum of the colloidal solution containing both the nanoparticles and U. longissima extract. Poly(ethylene glycol) coated silver nanoparticles showed additional absorption peaks at 424 and 450 nm. FTIR spectrum showed the involvement of amines, usnic acids, phenols, aldehydes and ketones in the reduction of silver ions to silver nanoparticles. Morphological studies showed three types of nanoparticles with an abundance of spherical shaped silver nanoparticles of 9.40-11.23 nm. Their average hydrodynamic diameter is 437.1 nm. Results of in vitro antibacterial activity of silver nanoparticles against Staphylococcus aureus, Streptococcus mutans, Streptococcus pyrogenes, Streptococcus viridans, Corynebacterium xerosis, Corynebacterium diphtheriae (gram positive bacteria) and Escherichia coli, Klebsiella pneuomoniae and Pseudomonas aeruginosa (gram negative bacteria) showed that it was effective against tested bacterial strains. However, S. mutans, C. diphtheriae and P. aeruginosa were resistant to silver nanoparticles. Conclusion: Lichens are rarely exploited for the fabrication of silver nanoparticles. In the present work the lichen acts as reducing as well as capping agent. They can therefore, be used to synthesize metal nanoparticles and their size may be controlled by monitoring the concentration of extract and metal ions. Since they are antibacterial they may be used for the treatment of bacterial infections in man and animal. They can also be used in purification of water, in soaps and medicine. Their sustained release may be achieved by coating them with a suitable polymer. Silver nanoparticles fabricated from edible U. longissima are free from toxic chemicals and therefore they can be safely used in medicine and medical devices. These silver nanoparticles were stable for weeks therefore they can be stored for longer duration of time without decomposition.