How long after Sculptra treatment do I need to wait to do PRP w/microneedling?

I would say in most cases, it probably would not make much difference how long you waited to have PRP with micro needling after a Scultpra treatment.  Sculptra is normally injected fairly deep and the depth of the micro needling would not reach as far as the Sculptra.  Just to be on the safe side, I would say you could wait a month in between the treatments.  

Sculptra is a
dermal filler that is injected deeply into the dermis or just below
the dermis of the skin to promote the production of new collagen.
Microneedling is performed on the surface (the epidermis) and can
reach down into the dermis, depending on the thickness of the skin
and length of the microneedles. You would not want deep
microneedling and Sculptra on the same day, as the Sculptra could
move too superficially and make a bump. Sculptra is a better
stimulator of collagen and is used to volumize, create a beautiful
facial shape, and firm up loose skin. Microneedling is more for
superficial skin texture and very fine wrinkles. If you have problems
with both volume loss and poor skin texture, I recommend completing
your 2 or 3 Sculptra sessions first. You may have so much skin
improvement that microneedling will be unnecessary. After treatment,
Sculptra can last 24 months or longer, so it will last much longer
than microneedling. However, if you just need surface improvement,
microneedling may be preferred. .
Generally,
I perform Sculptra injections and microneedling with PRP on the same
day. If you have Sculptra first, that's fine. You can go ahead and
find a board-certified dermatologist to help you with microneedling
at any time.

Thank you for the question. I have done both procedures at the same time with very good results. Both procedures work quite effectively for acne scarring and complement each other in terms of stimulating collagen production, "softening" the scars. In the same treatment session, I prefer to do the Sculptra injections first and finish with the PRP and micro needling. This way the PRP solution can be "painted" on the skin leaving a healing layer to continue to stimulate collagen superficially. 
Good luck and have a wonderful day.