Cutting elements, related methods of forming a cutting element, and related earth-boring tools

A method of forming a cutting element, comprising:

• providing a plurality of particles comprising a hard material into a container;
• providing another plurality of particles into the container, the another plurality of particles substantially laterally circumscribed by the plurality of particles;
• providing a supporting substrate into the container over the plurality of particles and the another plurality of particles;
• sintering the plurality of particles and the another plurality of particles of particles in the presence of a catalyst material to form a polycrystalline compact comprising a region adjacent an end of the supporting substrate, and another region at least substantially laterally circumscribing the region and having lesser permeability than the region;
• and
• removing at least a portion of the catalyst material from the polycrystalline compact.

An earth-boring tool comprising at least one cutting element comprising:

• a supporting substrate;
• and
• a polycrystalline compact attached to an end of the supporting substrate and comprising:
• a region adjacent the end of the supporting substrate;
• and
• another region at least substantially laterally circumscribing the region and having lesser permeability than the region.