Dynamically loading images as sprites and setting values like pixels per unit in code

Iam trying to load images as sprites dynamically since i want the possibility to add more tiles to the game. Using resources.load was not suited for this so i tried using WWW which worked up to a certain point.

I was not able to set the filtering and the pixels per unit. This resulted in that the sprites being way too small and blurry ingame. If possible i want to set these to 16 pixels per unit and using point as filter instead of bilinear.

For ppl wondering why i need this its because iam building a editor where a player can make a map and save it. The tiles have a resolution of 16x16 and i would like that the player can add new tiles to the game.