Article

pH-sensitive polymer nanospheres for use as a potential drug delivery vehicle.

Research Center for Biomolecular Nanotechnology, Department of Life Science, Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju, Republic of Korea.
Biomacromolecules (Impact Factor: 5.37). 12/2007; 8(11):3401-7. DOI: 10.1021/bm700517z
Source: PubMed

ABSTRACT We report the development and characterization of pH-sensitive poly(2-tetrahydropyranyl methacrylate) [poly(THPMA)] nanospheres and demonstrate their feasibility as an effective drug delivery vehicle. Poly(THPMA) nanospheres were prepared using either the double emulsion or single emulsion method for the encapsulation of, respectively, water soluble (rhodamine B) or organic soluble (paclitaxel) payloads. The resulting nanospheres showed pH-dependent dissolution behavior, resulting in significant morphologic changes and loss of nanoparticle mass under mild acidic conditions (pH 5.1) with a half-life of 3.3 days, as compared to physiologic condition (pH 7.4) with a half-life of 6.2 days. The in vitro drug release profile of the paclitaxel-loaded poly(THPMA) nanospheres revealed that the rate of drug release in pH 5.1 acetate buffer was relatively faster than that in pH 7.4 HEPES buffer. Furthermore, poly(THPMA) nanospheres showed lower cytotoxicity and higher cellular uptake as compared to the FDA-approved PLGA-based nanospheres currently in clinical practice.

0 Bookmarks
 · 
104 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: New type of hydrogel nanoparticles (HNp) based on chitosan are synthesized by the free radical graft-copolymerization reaction of peroxide containing chitosan derivative and 1-vinyl-2-pyrrolidone (VP) in the inverse miniemulsion droplets. Free radicals are formed upon thermal decomposition of the peroxide groups that are attached to the chitosan chain. After introduction of the cross-linker N,N-methylenebisacrylamide, more densely cross-linked HNp with a lower pH-dependant swelling rate are produced. The release behavior is investigated by fluorescence measurements using HNp loaded with either anionic sulforhodamine 101 or cationic rhodamine 123 fluorescent dye. The obtained results revealed that the crucial points in the release kinetic are the nature of used “payload” molecules and their interaction with the hydrogel matrix. Synthesized HNp are of potential interest for diverse biomedical applications including controlled drug release and diagnostic.
    Macromolecular Bioscience 04/2014; · 3.74 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction: Metal-organic frameworks (MOFs) are a unique class of hybrid porous solids based on metals and organic linkers. Compared to traditional porous materials, they possess predominance of large surface areas, tunable pore size and shape, adjustable composition and functionalized pore surface, which enable them unique advantages and promises for applications in adsorption and release of therapeutic agents. Areas covered: This review addresses MOFs as a new avenue for drug delivery and exhibits their ability to efficiently deliver various kinds of therapeutic agents. It also details the requirements that MOFs need to satisfy for biomedical application, such as toxicological compatibility, stability, particle size, and surface modification. In addition, several approaches used to enhance encapsulation efficiency are summarized and parameters influencing delivery efficiency are also discussed. Expert opinion: Benefiting from the unique advantages of MOFs materials, efficient delivery of various kinds of drugs has been achieved in some MOF materials. However, it is only the outset of MOFs in drug delivery system, and numerous work need to be done before clinical applications, for example, studying their in vivo toxicity, exploring degradation mechanisms so as to establish real stability of MOFs in body's liquid, providing appropriated surface modification avenue for MOFs, and researching in vivo efficiency and pharmacokinetics of drug-loaded MOFs.
    Expert Opinion on Drug Delivery 11/2012; · 4.87 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The possibility to control the fate of the cells responsible of secondary mechanisms following spinal cord injury (SCI) is one of the most relevant challenges to reduce the post traumatic degeneration of the spinal cord. In particular, microglia/macrophages associated inflammation appears to be a self-propelling mechanism which leads to progressive neurodegeneration and development of persisting pain state. In this study we analyzed the interactions between poly(methyl methacrylate) nanoparticles (PMMA-NPs) and microglia/macrophages in vitro and in vivo, characterizing the features that influence their internalization and ability to deliver drugs. The uptake mechanisms of PMMA-NPs were in-depth investigated, together with their possible toxic effects on microglia/macrophages. In addition, the possibility to deliver a mimetic drug within microglia/macrophages was characterized in vitro and in vivo. Drug-loaded polymeric NPs resulted to be a promising tool for the selective administration of pharmacological compounds in activated microglia/macrophages and thus potentially able to counteract relevant secondary inflammatory events in SCI.
    Journal of Controlled Release 11/2013; · 7.63 Impact Factor