A new method for precise delivery of nanoparticles and small molecules to individual cells

Delivering experimental materials to individual cells with precision and exclusivity has long been an elusive and highly sought-after capability in biology. With this comes the promise of deciphering many of the cell’s long-held secrets.

A research team from the Max-Planck-Zentrum für Physik und Medizin in Erlangen led by Professor Vahid Sandoghdar has successfully shown how small molecules and unique nanoparticles can be applied directly to the surface of cells.

In the study published in Natural methodsThe scientists describe their technique as a “μkiss” (microkiss) – a new, simple and cost-effective method, opening new possibilities in single-cell science for next-generation therapeutic applications.

Traditional approaches in biology often consider the characteristics of entire cell populations, without accounting for nuanced variations in properties from cell to cell. To study biology more precisely at the individual cellular level, the development of new tools and methods is imperative.

“A crucial gap remains in our ability to deliver chemicals, tags and pharmaceuticals to individual cells with precision and control, over short durations and at tiny microscopic scales,” says Professor Vahid Sandoghdar, director of the Max Planck Institute for the Science of Light. and Max-Planck-Zentrum für Physik und Medizin. Professor Sandoghdar and his team are actively tackling this challenge.

“Like a paintbrush”, easy and economical to use

The researchers developed a simple but elegant solution to this problem: using two closely spaced micropipettes with an opening as small as a micrometer, scientists were able to create a stable micrometer-sized droplet at the ends of the micropipette using a micropipette to distribute the product. material, while the other sucks it in at a slightly higher rate.

“It’s then like a paintbrush,” says postdoctoral researcher and team member Richard W. Taylor, adding, “You can easily maneuver the micropipettes and gently brush this confined droplet against the cell of your choice, delivering a little kiss of matter.”

This simple implementation, using readily available components, allows their technique to be easily implemented at low cost on any microscope in biological laboratories.

“The cost-effective and pragmatic approach of our solution is important for its practical use,” says Professor Sandoghdar, adding: “The lack of similar solutions has so far delayed progress towards new therapeutic approaches at the single-cell level.”

Full control over location, time and scale

The new method gives the experimenter complete control. “With μkiss, we are reaching a completely new dimension in the precise application of substances to cells,” explains Cornelia Holler, doctoral student in biology and member of the research group. Materials can now be precisely delivered to any chosen cell at the subcellular level, with full control over the time and position that the material is in contact with the cell.

“We can now observe entire biological processes, such as the uptake of iron by the cell, without missing a step. This allows us to finally piece together the puzzle of the complex characteristics of each individual cell,” explains Holler.

Recently, the team managed to precisely place a single virus-like particle on a living cell. This experimental capability creates the opportunity to examine the intricacies of disease spread, providing complete control over the location, timing, and extent of cellular infection.

“The capacity of μkiss opens new avenues for quantitative studies in cell biology and medicine,” explains Professor Sandoghdar.