geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Preparation of a novel PEG-clay hybrid as a DDS material: dispersion stability and sustained release profiles


, : Preparation of a novel PEG-clay hybrid as a DDS material: dispersion stability and sustained release profiles. Journal of Controlled Release 107(3): 408-416

An advanced hybrid drug carrier has been developed using porous nanocrystals of a swelling clay mineral conjugated with a block copolymer containing poly(ethylene glycol) and polyamine segments. Synthetic hectorite (Laponite) modified with ((Xacetal-poly(ethylene glycol)-block-[poly(2-(N,N-dimethylamino) ethyl methacrylate)] (Acetal-PEG-b-PAMA) produced a homogeneous dispersion of organic-inorganic hybrid in an aqueous solution, which showed flocculation-resistive properties with an elevated ionic strength. The zeta-potential measurement revealed that nonionic PEG brush layers are formed on the surface of the clay nanocrystals since negative charge of the clay surface was completely neutralized by the positive charge of the cationic PAMA segment and the entire surface charge is successfully shielded by the effect of nonionic PEG segment in the block copolymer. This charge neutralization is in good agreement with the dispersion stability in solutions of high ionic strength. The average particle size of the PEG-modified hybrid particle was estimated to be 120 nm by a dynamic light scattering (DLS) method. When pyrene was used as the model compound of hydrophobic drug, it was incorporated into the nanopore in the clay mineral without showing any remarkable expansion of the basal spacings. Fluorescence spectra and powder X-ray diffraction patterns demonstrated that pyrene molecules are captured in an amorphous state in the range of low pyrene content (< 5%), while excimer formation was seen at the higher pyrene concentration (> 5%). The PEG-clay hybrid act as a carrier for sustained release of hydrophobic substances due to the high affinity (K = 1.52 x 10(4)) between the drug and clay surface. (c) 2005 Elsevier B.V. All rights reserved.

US$19.90

PMID: 16171884

DOI: 10.1016/j.jconrel.2005.03.031


Other references

Torres, V.A., 2015: Rab'ing tumor cell migration and invasion: focal adhesion disassembly driven by Rab5. The small GTPase Rab5 has been extensively studied in the context of endocytic trafficking because it is critical in the regulation of early endosome dynamics. In addition to this canonical role, evidence obtained in recent years implicates Rab5 i...

Lewis, C.; Elnitsky, C., 1993: Ethical and policy implications for the allocation of health care services to elderly persons in rural America. Nursingconnections 6(1): 26-30

Rukazambuga, N.D.T.M.; Gold, C.S.; Gowen, S.R.; Ragama, P., 2002: The influence of crop management on banana weevil, Cosmopolites sordidus (Coleoptera: Curculionidae) populations and yield of highland cooking banana (cv. Atwalira) in Uganda. A field study was undertaken in Uganda using highland cooking banana (cv. Atwalira) to test the hypothesis that bananas grown under stressed conditions are more susceptible to attack by Cosmopolites sordidus (Germar). Four banana treatments were e...

Thornber M.R.; Morris R.C., 1983: The formation of iron ore from banded iron-formation by an electrochemical weathering process. Research Review - CSIRO Division of Mineralogy Pages 84-85

W.X.hao; Qian Fang, 1980: Geomorphology of the river valleys in the drainage system of the Golmud River. Pages 130-131 1980

Caudwell, A.; Hewitt, W.B.; Bovey, R., 1972: Viruses of grapevines. Bibliography from 1965-1970. This bibliography lists 366 references on grapevine viruses collected by representatives from 25 countries at the instigation of the International Council for the Study of Viruses and Virus Diseases of the Grape (ICVG). It continues the first list...

Kecskes, L.; Mutschler, F.; Kobor, J., 1963: Tissue estrogen determinations in ovarian tumors. Zentralblatt für Gynakologie 85: 325-328

Milroy, C.M.; Clark, J.C.; Carter, N.; Rutty, G., 1997: Toy story Airgun fatalities. Journal of Pathology 182(SUPPL ): 42A

Kawalchuk M., 1988: The effect of aspartame on weight loss. American Journal Of Clinical Nutrition: 767

Holloway Ralph L., 1985: The past, present and future significance of the lunate sulcus in early hominid evolution. Pages 47-62 1985