Microcarrier Processing within the Cell

Microcarrier Processing within the Cell

Development and design of colloidal microcarriers as drug delivery system require a profound knowledge of the carrier adsorption on cell membranes, endo-/phagosomal uptake by cells, processing within endo-/phagolysosomes and the potential release of the carriers within the targeted cell compartment, such as endo-/phagolysosome or cytoplasm, to deliver the agents with full activity but only low carrier-induced negative effects on the cell.

Focus on:

  • Biopolymers with specific properties for multilayer disassembly in

    • phagolycosomes
    • cytoplasm

  • LbL particles vs. LbL capsules
  • Integration of and for carrier tracking and quantification during all stages of processing using

    • pH sensors
    • plasmid-DNA coded for fluorescent proteins
    • nanoparticles
    • fluorescence labelled polymers

  • Development and integration of to facilitate specific demands to

    • protect active agents
    • gain access to cytoplasm
    • support targeted multilayer disassembly

Fig.: Processing Carriers

Carrier and Drug Delivery into Cytoplasm

One the one hand, we focus on the carrier transport into cytoplasm, the cell compartment most frequently targeted for drug delivery. After uptake, the endo-/phagolysosomal barrier has to be overcome, a general problem in efficient drug delivery, since the degrading potential of enzymes may reduce the carrier efficacy.

However, to design an efficient drug delivery system, sensor components are required to assess and quantify carrier release rate, time frame and remaining activity of the delivered agent. Recent investigations use multilayer-integrated plasmid DNAs (pEGFP, pDsRed) as reporters which are coded for fluorescent proteins (1,2) to prove the carrier efficacy. Successful transport and delivery into the cytoplasm of cells can thus be visualized by confocal microscopy (CLSM) and flow cytometry (FCM) after protein expression(1). The additional integration of pH sensors into the core as well as fluorescence labelled polymers facilitate the quantification of the carrier processing from endo-/ phagolysosome to cytoplasm(2-4). The following time-dependent multilayer decomposition within the cytoplasm can be observed e.g. by using magnetite nanoparticles as reporters which are integrated into the multilayer(5). Their release by means of a step-by-step multilayer disassembly is then detectable by means of ion beam techniques (as Proton-Induced X-ray Emission (PIXE)).

Relevant Publications

Reibetanz, U., Claus, C., Typlt, E., Hofmann, J., Donath, E. Defoliation and Plasmid Delivery with Layer-by-Layer Coated Colloids. Macromol. Biosci.  6 (2006) 153-160. [DOI, PubMed]

Reibetanz U, Chen MHA, Mutukumaraswamy S, Liaw ZY, Oh BHL, Venkatraman S, Donath E, Neu B. Colloidal DNA Carriers for Direct Localization in Cell Compartments by pH Sensoring. Biomacromolecules 11 (2010) 1779-1784.  [http://dx.doi.org/10.1021/bm100237rPubMed]

Reibetanz, U., Halozan, D., Brumen, M., Donath, E. Flow Cytometry of HEK 293T Cells Interacting with Polyelectrolyte Multilayer Capsules Containing Fluorescein-Labeled Poly(acrylic acid) as a pH Sensor. Biomacromolecules 8 (2007) 1927-1933. [DOI, PubMed]

Reibetanz U, Chen M H A, Mutukumaraswamy S, Liaw Z Y, Oh B H L, Donath E, Neu B. Functionalization of Calcium Carbonate Microparticles as a Combined Sensor and Transport Sytem for Active Agents in Cells. J. Biomat. Sci.-Polym. E. 22 (2011) 1845–1859. [DOI]

Reibetanz U, Jankuhn S. Magnetite Nanoparticles as Reporters for Microcarrier Processing in Cell Cytoplasm. Nucl. Instrum. Meth. Phys. Res. B 269 (2010) 2281-2285. [DOI] 

Fig.: Multilayer

letzte Änderung: 08.06.2017