• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.51.2-51.2
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• 2011

A novel electrospun nanofiber membrane was fabricated using combined poly (vinylphosphonic acid) (PVPA) and polyvinyl alcohol (PVA) intended for bone tissue engineering applications. PVPA is a proton-conducting polymer used as primer for bone implants and dental cements to prevent corrosion and brush abrasion. The phosphonate groups of PVPA have the ability to crosslink and attach itself to the hydroxyapatite surface facilitating faster integration of the biomaterial to the bone matrix. PVA was combined with PVPA to provide hydrophilicity, biocompatibility and improve its spinnability. To improve its mechanical strength, PVPA/PVA and neat PVA mixtures were combined to produce a multilayer scaffold. The physical and chemical properties of the of the fabricated matrix was investigated by SEM and TEM morphological analyses, tensile strength test, XRD, FT-IR spectra, swelling behavior and biodegradation rates, porosity and contact angle measurements. Biocompatibility was also examined in vitro by cytotoxicity and cell proliferation studies with MTT assay and cell adhesion behavior by SEM and confocal microscopy.

• FLOWER RESEARCH JOURNAL
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• v.16 no.4
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• pp.325-332
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• 2008

This paper outlines the system and operation of plant variety protection right and plant patent of ornamental crops in USA to guide for application of new varieties developed in Korea and to use for national examination of applied variety from USA. The Plant Variety Protection Act(PVPA) in USA is given as PVPR to the developers of new variety for the seed propagating crops and tubers and provides as plant patent for asexually reproducing crops. A certificate of PVPR and plant patent is awarded to an owner of a variety has shown that it is new, distinct from other varieties, genetically uniform and stable through successive generations by official evaluation without the growing trial. The term of protection for plant patent and PVPR for most crops is 20 years but 25 years for trees, shrubs, and vines. The application of ornamental variety in USA is mostly for plant patent. The application of ornamental crops accounted for 87% of total applications for plant patent. The ratio of new variety applications for plant patent from national and foreign countries is not significant differences.