Unilateral Resource Management in a Two-Country General Equilibrium Model of Trade in a Renewable Fishery Resource

We explore the effects of free trade in a renewable natural resource between two countries in the presence of incomplete property rights. While resource management by one country may benefit one or both trading partners, we demonstrate that resource management by only one of the partners may reduce welfare for both, when compared to the case in which neither manages its resource sector. These trade-induced losses may be reduced through import tariffs and production subsidies on the resource good or by permitting harvest beyond the rent-maximizing level. Our preliminary work suggests that the World Trade Organization (WTO) and North American Free Trade Agreement (NAFTA) policy makers should not always insist on free trade and resource management. Rather, they must pay careful attention to the particular relationships between trade conditions and natural resource policies among trading nations. Copyright 2000, Oxford University Press.

Chemosensitization of cancer cells by siRNA using targeted nanogel delivery

© 2010 Dickerson et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1471-2407/10/10DOI: 10.1186/1471-2407-10-10Background. Chemoresistance is a major obstacle in cancer treatment. Targeted therapies that enhance cancer cell sensitivity to chemotherapeutic agents have the potential to increase drug efficacy while reducing toxic effects on untargeted cells. Targeted cancer therapy by RNA interference (RNAi) is a relatively new approach that can be used to reversibly silence genes in vivo by selectively targeting genes such as the epidermal growth factor receptor (EGFR), which has been shown to increase the sensitivity of cancer cells to taxane chemotherapy. However, delivery represents the main hurdle for the broad development of RNAi therapeutics. Methods. We report here the use of core/shell hydrogel nanoparticles (nanogels) functionalized with peptides that specially target the EphA2 receptor to deliver small interfering RNAs (siRNAs) targeting EGFR. Expression of EGFR was determined by immunoblotting, and the effect of decreased EGFR expression on chemosensitization of ovarian cancer cells after siRNA delivery was investigated. Results. Treatment of EphA2 positive Hey cells with siRNA-loaded, peptide-targeted nanogels decreased EGFR expression levels and significantly increased the sensitivity of this cell line to docetaxel (P 0.05)

Design of Multifunctional Nanomedical Systems

Multifunctional nanoparticles hold great promise for drug/gene delivery and simultaneous diagnostics and therapeutics ( theragnostics ) including use of core materials that provide in vivo imaging and opportunities for externally modulated therapeutic interventions. Multilayered nanoparticles can act as nanomedical systems with on-board molecular programming done through the chemistry of highly specialized layers to accomplish complex and potentially decision-making tasks. The targeting process itself is a multi-step process consisting of initial cell recognition through cell surface receptors, cell entry through the membrane in a manner to prevent undesired alterations of the nanomedical system, re-targeting to the appropriate sub-region of the cell where the therapeutic package can be localized, and potentially control of that therapeutic process through feedback systems using molecular biosensors. This paper describes a bionanoengineering design process in which sophisticated nanomedical platform systems can be designed for diagnosis and treatment of disease. The feasibility of most of these subsystems has been demonstrated, but the full integration of these interacting sub-components remains a challenge for the field. Specific examples of sub-components developed for specific applications are described