Related Experiment Video
Updated: Aug 13, 2026
10:30
Delivery of Proteins, Peptides or Cell-impermeable Small Molecules into Live Cells by Incubation with the Endosomolytic Reagent dfTAT
Published on: September 2, 2015
D-TAT transporter as an ocular peptide delivery system
Daniel F Schorderet1, Violaine d'Allèves Manzi, Kriss Canola
1IRO-Institut de Recherche en Ophtalmologie, Sion, Switzerland. daniel.schorderet@iro.vsnet.ch
Clinical & Experimental Ophthalmology
|January 13, 2006
Summary
The retro-inverso TAT (D-TAT) peptide effectively delivers molecules to eye cells, offering a promising alternative to gene therapy. This D-TAT peptide shows longer persistence in retinal cells compared to its counterpart, suggesting therapeutic potential.
Area of Science:
- Ophthalmology
- Molecular Biology
- Biotechnology
Background:
- Virus-mediated gene therapy for genetic diseases faces ethical and scientific challenges.
- Alternative molecular treatments are being explored for conditions like genetic eye diseases.
- The HIV-1 trans-activator protein (TAT) peptide facilitates cellular membrane transport, but has a short half-life.
Purpose of the Study:
- To investigate the potential of the retro-inverso form of TAT (D-TAT) peptide as a molecular transporter for eye diseases.
- To evaluate the efficacy and duration of D-TAT peptide transduction in photoreceptor cells.
Main Methods:
- FITC-labelled D-TAT (D-TAT FITC) was applied to murine photoreceptor cell lines in culture.
- D-TAT FITC was administered via intravitreal or subretinal injection in adult mice.
- Fluorescence microscopy and coimmunostaining were used to analyze peptide uptake and cell transduction.
Main Results:
- D-TAT effectively transduced photoreceptor cells in both cell culture and in vivo models.
- In vivo, D-TAT FITC demonstrated longer persistence in retinal cells compared to L-TAT FITC.
- Visible D-TAT FITC was observed in the retina for at least 14 days post-injection.
Conclusions:
- The D-TAT peptide is effective in transducing various eye cell compartments.
- D-TAT offers a more sustained molecular transport mechanism than L-TAT.
- D-TAT holds potential as a molecular transporter for targeted ocular therapies requiring long-lasting effects.
Related Concept Videos
01:23Ophthalmic Drug Delivery Systems
Ophthalmic drug delivery faces major limitations due to poor absorption across the corneal membrane. This process is primarily driven by diffusion and is influenced by two main factors: the physicochemical properties of the drug and tear drainage. Most ophthalmic drugs, such as pilocarpine, epinephrine, atropine, and local anesthetics, are weak bases. They are typically formulated at an acidic pH to enhance chemical stability. However, this leads to high ionization, reducing their ability to...
01:24Site-Targeted Drug Delivery Systems: Polymeric Carriers
Polymeric carriers enhance targeted drug delivery by increasing efficacy while minimizing off-target effects. These carriers comprise a biodegradable polymeric backbone integrated with functional elements that enable targeting, improve physicochemical properties, and regulate drug release.Targeting MechanismsThe targeting ability of polymeric carriers is mediated by a homing device, which is a molecular recognition component designed to selectively bind to specific tissues or cells. Monoclonal...
01:06Carrier-Mediated Transport
Carrier-mediated transport is a pivotal process in drug absorption, particularly for lipid-insoluble drugs, and encompasses facilitated diffusion and active transport. Facilitated diffusion allows drugs to move along their concentration gradient without energy expenditure, while active transport utilizes ATP to drive drug movement against this gradient.
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
01:24Modified-Release Drug Delivery Systems: Site-Targeted
Site-targeted drug delivery systems enhance therapeutic efficacy while minimizing systemic toxicity and treatment costs. Unlike conventional methods, these systems ensure precise drug delivery, improving bioavailability and reducing side effects. Targeted drug delivery is classified into three levels. First-order targeting directs drugs to the capillary beds of specific organs or tissues. Second-order targets specific cell types, such as tumor cells, using receptor-mediated interactions.
01:22Protein Transport to the Thylakoids
Thylakoids are membrane-bound sac-like structures within the chloroplast that serve as sites for photosynthesis. Thylakoid lumen contains many electron transport proteins and is enclosed by a thylakoid membrane rich in the light-harvesting complex. Proteins targeted to the thylakoids are transported as precursors and are sorted by the general TOC/TIC import pathway. Once the precursor reaches the stroma, stromal processing peptidases remove their transit signal and expose thylakoid signal...
01:11Protein Transport to the Outer Chloroplast Membrane
Chloroplast outer membrane proteins encoded by the nucleus are synthesized in the cytosol. Soon after synthesis, they bind cytosolic factors such as 14-3-3 protein and the Hsp70 chaperones that keep these precursors in an unfolded state until their translocation.
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.