Even I am in my holidays at the moment but still I am interested and reading more and more about the best way how to prevent or even decrease the risk of lumps or even nodules formation , what I have found there are scientists trying to find the best way to prevent clumping of e.g. PMMA beads ----> less nodules and lumps, as we know for a solid pmma bead ( a density of 1.2 g/cm3)you need a higher viscous carrier e.g bovine collagen ( a density of 1.04 g/cm3) (e.g. in Artefill) and thats why stil with this carrier the beads still precipitate also when the filler is in the body; our body temp. reduces the carrier viscosity and thus accelerate the precipitation of the particles. So this will be the same or even worse with the weaker brazilian pmma carrier (CMC) .
So these guys thought about decreasing the density of the beads without damaging them they void (empty) the bead and filled it either with air or gas or even fluid, and they made different volume of these voids and with different shape and either single or multiple.
So a plurality of injectable hollow particulates filler ( each hollow particle has a shell of biocompatible material and a hollow interior).
The hollow beads have effective density comparable to the carrier and suspend evenly in the carrier outside the body and in the body.
With this invention the carrier mixed with the hollow beads can posses a low vicosity without causing precipitation. The choice of a suitable carrier will depend on the particle size, the amount of filler etc. . Even the carrier can be saline or PBS solution or even water with no clumping of pmma beads ---> i.e. less chance of nodules and lumps.
How hollow can bead that small be? Is it even possible to make beads that small hollow?
I think a 10% solution with a bovine carrier is the answer. But the trouble is, Artefil have a patent and 10% isn\'t good for further top ups.
I\'ve figured out why that is now, btw. Each bead needs to be encapsulated in collagen. During the first round the amount of beads doesn\'t make much difference as the total surface area isn\'t that different as beads that are close together see collagen formation overlap or become denser. There will be a slight, but not much difference. But with round two, this slight difference becomes much more apparent as the new beads are being injected where there is already collagen formation If anything 10% will just make the old collagen more dense and hence we have seen people making no gains at all. You could almost say that you are just turning old PMMA into 20% concentration.
For an example a pmma bead of 30 micron diam. ( in artefill the beads diam. Is betw. 32-40 microns) i.e. a radius of 15 micron and you want to make it hollow :-
1- For heavy density carrier e.g. bovine collagen you wil need a smaller volume of void just to be near the density of the carrier ( i.e. 1.04 g/cm3) so what this guy made he made the radius of the void around 7.66 microns ( not to forget the radius of the pmma as a whole is 15 microns, so by this radius of the void he made the density of the hollowed pmma beads so that they won\'t precipitate in bovine collagen; so would that mean these hollow pmma beads if they were used instead of the solid pmma beads in Artefill will be better in regard of no precipitation ( because they are lighter).
2- For lighter density carrier e.g. Saline ( density around 1 g/cm3) you will need pmma beads which are lighter ( the volume of the void is larger) than the above one, so this guy found that for the 30 microns diam. pmma ( a radius of 15) he nead to make the radius of the void 8.25 microns ( i.e. an increase in radius of the void about 0.59 microns) just to prevent these type of hollow beads not to precipitate in Saline.
So in conclusion to avoid any precipitation or clumping of the beads in two different density carriers :-
1- In bovine collagen you will nead a hollow pmma bead of a radius of the void of 7.66 microns and with an outer radius of 15 microns.
2- In Saline you will nead a hollow pmma bead of a radius of the void of 8.25 microns and with an outer radius of 15 microns.
Check this site which explain it much better with diagrams :-
Sounds like a good idea, but how will the mfg \"quality control\" to make sure all the beads are hollow, evenly round and sealed? what happens of some beads leak and fluid gets inside? will one now get clumping? Will the cost of manufacturing be so high due to tighter tolerances and quality controls?
That is true, we have to know more about these hollow PMMA beads ( micro- balloons) btw these are made for a longer priod ( for drug delivery, in cosmetic etc. ).
There was always the idea to find a strong carrier which has a density almost near to the PMMA density i.e. 1.2 g/cm3 ( actually it is exactly 1.19g/cm3) but the problem with that type of carrier will be very viscose and will be very difficult even impossible to be injected through a needle, Lemperle mentioned before you need a strong carrier for the PMMA beads just to distrbute them evenly and thats why he said the carrier in the brazillian products Cellulose is a weak carrier and cannot carry the beads i.e. precipitation will definitely occur ----> nodules or even lumps.
So we have either of 2 choices :- one to increase the density of the carrier which was explained why it wil be difficult or to reduce the dendity of the PMMA beads by forming different sizes of micro- balloons PMMA i.e. different volumes of voids which depends on the chosened carrier ( i.e. its density) .
I think with this Patent the inventor did solve a major problem in regard how to make these PMMA beads floating within the carrier without a chance of precipitation.
The best way is to examine these micro- balloons mixed with a filler with the same density in vitro and in vivo ( after few monthd) under SEM.
It will be great if we could contact this inventor ..
I had a reply from Lemperle :-
this is certainly a good idea for indications copied from our \"Lemperle-Patent\" . The problem again is the FDA, who has once approved solid microspheres (from PMMA and Ca) - and all new inventions have to prove their safety and effectivity through new clinical trials... (which may cost $ 5-10 million).
That non-flexible behavior of the FDA inhibits progress tremendously. Best, Gottfried