A molecular method for the delivery of small molecules and proteins across the cell wall of algae using molecular transporters

Abstract

Interest in algae has significantly accelerated with the increasing recognition of their potentially unique role in medical, materials, energy, bioremediation, and synthetic biological research. However, the introduction of tools to study, control, or expand the inner-workings of algae has lagged behind. Here we describe a general molecular method based on guanidinium-rich molecular transporters (GR-MoTrs) for bringing small and large cargos into algal cells. Significantly, this method is shown to work in wild-type algae that have an intact cell wall. Developed using Chlamydomonas reinhardtii , this method is also successful with less studied algae including Neochloris oleoabundans and Scenedesmus dimorphus thus providing a new and versatile tool for algal research.

Cell penetrating peptide can transport dsRNA into microalgae with thin cell walls

“…It has been reported that fluorescein-labeled octa-arginine (Fl-R8) can cross the cell wall of C. reinhardtii, algal cell uptake of Fl-R8 increases as the concentration of Fl-R8 increases, and a concentration of 50 μM is sufficient for strong internalization of F1-R8 [7]. It was also shown that Fl-R8 could enter different species of freshwater green algae but that cellular uptake was species specific.…”

“…The translocation of CPPs into microalgae was performed following a previously described method with slight modifications [7]. FITC-R9 and free FITC were dissolved separately in phosphate buffered saline (PBS) to 50 μM.…”

“…To date, few studies of the use of CPPs have been conducted on higher plant cells [11][12][13]. As for algae, Hyman, Geihe, Trantow, Parvin and Wender [7] used octa-arginine and nona-arginine to transfer fluorescein, protein, and enzyme into Chlamydomonas reinhardtii, and Suresh and Kim [14] compared the internalization efficiency of different CPPs applied to C. reinhardtii. These studies showed that CPPs can be used to transport proteins into algal cells, but transductions of other macromolecules, such as nucleic acid substances, into algae have not yet been verified.…”

“…Complex microalgal cell barriers, which are difficult to overcome, have severely limited the delivery of exogenous substances into cells. Recently, however, researchers developed a new molecular tool that uses cell penetrating peptides (CPPs) to carry macromolecules across cell walls and cell membranes into microalgae [7]. This method is easy to apply and inexpensive and has opened up new possibilities for algal transforming research.…”

Template-synthesized gold microneedle arrays for gene delivery to the Chlamydomonas reinhardtii chloroplast

“…Genetic modification is a crucial component for microalgal studies to understand and control the complex biological pathways, and realize higher photosynthetic efficiency, more consistent product quality, and higher resistance to pathogens [6,7]. However, the hard cell wall of the microalgae acts as a formidable barrier to the insertion (or delivery) of genetic materials [8].…”