I've been getting alot of questions about this one so I'll put some clarification here. PolyVivo AK12 (PLGA-PEG-PLGA ~1000-1000-1000) when it is dry state appears to be a gelatinous material. It is not diluted with anything, this is its normal appearance. It is very sticky and viscous when in dry state at room temperature. At -20C it is hard as glass and nearly impenetrable to most spatula's. It is suggested to warm the bottle gently (few minutes in 37C incubator) prior to transfer as it will be fluid enough in dry state at 37C to be scooped into another vial. It is not suggested that you store the bottle at 37C as long-term storage at this temperature could damage the polymer, only warm to 37C prior to transfer and try to do this as few times as possible to avoid polymer damage.
When this polymer is dissolved in water or saline at roughly 20% w/v solution it will act as a thermoreverse gelator. Dissolves best at 4C (refrigerator) temperature typically overnight or over a few days and then use for your purpose. When warmed the solution will gel. Gelation is optimal at room temperature (20-25C). The polymer tends to solidify at 37C and after a short time will release the water and return to solid polymer.