Q: Do you need to reformulate the particles for each new cargo?

No—we do not need to reformulate the particles for each new cargo. Although surface charge can be tuned based on the payload, the coordination-stabilized core supports direct post-synthesis functionalization without modifying the underlying synthesis.

Q: What is the surface chemistry of your particle?

Our particles present a coordination-driven, zwitterionic surface composed of iron-bound ligands, including magnesium, citrate, and phosphocholine, enabling dynamic and biologically interactive interfaces.

Q: What is the surface charge of your particles?

The PA-001 particle is -27 mV. Our particles designed for RNA loading are -17 mV, to compensate for the negative charge of 5-10 RNA molecules/particle.

Q: Are these coated particles or are components integrated into the structure?

In addition to iron oxide, our particles incorporate magnesium and a coordinated set of ligands, including citrate, phosphocholine, and dextran, that are integrated during formation and collectively define particle stability and surface behavior.

Q: Can your particles be used for drug development?

Yes. Our process and particles are GMP compatible. Paretor is a manufacturer, not a pharmaceutical company. Novel cargos and uses can be patented and developed. Off the shelf particles are available to the research community for purchase.

Q: Do particles have any biological activity or are they just for delivery?

Yes, if desired. Independent of cargo, the particles demonstrate measurable biological effects. In our system, exposure to the particle alone increased cell viability under stress conditions, indicating that the material itself can modulate cellular state.

Question 1

How are your nanoparticles different from other iron oxide nanoparticles?

Accepted Answer

Our nanoparticles differ from traditional, legacy iron oxide nanoparticles in a fundamental way: instead of being stabilized by a crystalline magnetic core (like magnetite or maghemite), they are intentionally non-crystalline and non-magnetic, with stability governed by coordination chemistry during formation rather than lattice structure. This eliminates the magnetic interactions that typically drive aggregation and, importantly, leaves the particle surface accessible and chemically addressable after synthesis, enabling direct functionalization with nucleic acids or other cargos without reformulation. As a result, these particles behave less like inert magnetic carriers and more like dynamic, biologically interactive colloids—supporting post-synthetic modification, scalable single-pot manufacturing, and distinct cellular interactions that are not readily achievable with conventional spinel iron oxide systems.

Question 2

Are your nanoparticles magnetic?

Accepted Answer

No, our particles are not magnetic. They are stabilized through coordination chemistry during formation, rather than traditional spinel crystallinity.

Question 3

Is synthesis scalable?

Accepted Answer

Yes. Ours is an automatable one-pot synthesis, which takes 140 minutes to complete. Our ingredients are stoichiometrically exhausted and synthesis efficiency is >95%. Particles can be used right after synthesis without dialysis and there is very little to no free iron in the product.

Question 4

How big are your nanoparticles?

Accepted Answer

Deriving from our combinatorial mineral nanoparticle library, individual Paretor nanoparticles have a hydrodynamic diameter of 45 nm and have a uniform size distribution (PDI <0.3).

Question 5

Do you need to reformulate the particles for each new cargo?

Accepted Answer

No—we do not need to reformulate the particles for each new cargo. Although surface charge can be tuned based on the payload, the coordination-stabilized core supports direct post-synthesis functionalization without modifying the underlying synthesis.

Question 6

What is the surface chemistry of your particle?

Accepted Answer

Our particles present a coordination-driven, zwitterionic surface composed of iron-bound ligands, including magnesium, citrate, and phosphocholine, enabling dynamic and biologically interactive interfaces.

Question 7

What is the surface charge of your particles?

Accepted Answer

The PA-001 particle is -27 mV. Our particles designed for RNA loading are -17 mV, to compensate for the negative charge of 5-10 RNA molecules/particle.

Question 8

Are these coated particles or are components integrated into the structure?

Accepted Answer

In addition to iron oxide, our particles incorporate magnesium and a coordinated set of ligands, including citrate, phosphocholine, and dextran, that are integrated during formation and collectively define particle stability and surface behavior.

Question 9

Can your particles be used for drug development?

Accepted Answer

Yes. Our process and particles are GMP compatible. Paretor is a manufacturer, not a pharmaceutical company. Novel cargos and uses can be patented and developed. Off the shelf particles are available to the research community for purchase.

Question 10

Do particles have any biological activity or are they just for delivery?

Accepted Answer

Yes, if desired. Independent of cargo, the particles demonstrate measurable biological effects. In our system, exposure to the particle alone increased cell viability under stress conditions, indicating that the material itself can modulate cellular state.

Question 11

How stable are your particles?

Accepted Answer

The particles are colloidally stable, free–thaw stable, and maintain a consistent size distribution and surface charge. Their coordination-driven structure supports stability in aqueous conditions without aggregation. Particles are stable at -20℃ for 9 months and at 4℃ for up to 6 weeks.

Question 12

Do your particles release free iron or degrade under physiological conditions?

Accepted Answer

Under tested conditions, the ferric iron-based particles remain structurally intact and do not release measurable levels of diffusible iron. Buffer exchange does not alter their optical profile, supporting that iron remains particle-associated with minimal free iron residuals following synthesis.

Question 13

What types of cargo can they carry?

Accepted Answer

The particles support post-synthesis functionalization and can carry a range of cargos, including nucleic acids such as siRNA, small molecules, peptides, antibodies, as well as other molecules that can interact with the particle’s coordination-accessible surface.

Question 14

How is cargo conjugated to the particle?

Accepted Answer

Under field-ready conditions, cargo is conjugated post-synthetically through coordination-accessible iron sites and surface-presented reactive groups, such as maleimide, which enable binding to thiolated molecules like siRNA. This process is stoichiometric and scalable, allowing predictable surface loading without reformulating the particle itself. Any click chemistry that can be phosphonate-associated is also possible.

Question 15

Can you help me add my own cargo to the particle?

Accepted Answer

Yes, we offer bespoke particle synthesis. Please contact us for information.

Frequently Asked Questions