In one embodiment, a radiation shielding composition comprises lead oxide or lead composite material of predetermined particle size, and an adhesive, wherein the composition comprises free flow property. A gravity flow photobioreactor farm comprised of a settling tank ; a pump ; a plurality of bioreactor cores connected in series at decreasing elevations and a return pipe. A tip extends from the housing for touching a patient’s skin. During a first predetermined part of an operational cycle of the dispenser, the gas generator is energized at a first level.