This link is representative of using nano gold particles (aka colloidal inert gold) as a possible delivery system medically for chemo agents or antibiotics in living systems. I am finding basically only "drug delivery" studies on PubMed for nano gold particle use medically.

The influence of the route of administration of gold nanoparticles on their tissue distribution and basic biochemical parameters: In vivo studies. - PubMed - NCBI
This article is from 2015.

Now, the following link is an example of the confusion about gold mentioned in the first post I made here about ionized
gold. (gold chloride which is soluble gold)

Colloidal Gold Benefits

It appears to me that the second link here, in this post is confusing ionic with colloidal (inert gold).

One needs to be very careful looking up things on the internet, as lay articles can be misleading.

Adding to this discussion:

As Neurochic and mrsD have pointed out, gold metal (Au) is quite inert. That is why it is sometimes used in dental fillings and as an (expensive!) additive to some food products. Some allegedly beneficial health products are marketed as being "colloidal gold". Roughly speaking, what colloidal means in this context is "containing very small bits of gold metal". This does not change the fact that gold metal is chemically inert so I think that it is very unlikely that these products will provide any benefit.

Gold cations (Au(I) or Au(III)) are different. They are soluble in water (gold metal is not) and are chemically quite reactive. As mrsD has explained, there is evidence that ingesting gold cations (in the same way as ingesting cations of other heavy metals) can have adverse health effects.

In my view eating gold metal is pointless from a health perspective but eating heavy metal cations potentially leads to significant health risks.