The subject invention pertains to novel materials and methods for use in delivering and sequestering substances, such as pharmacological agents, within a patient. One aspect of the invention is directed towards core-shell particles having a core encapsulated within a calcium carbonate shell, with an intermediate layer composed of an amphiphilic compound surrounding the core. When the particles of the subject invention are administered to a patient, they are capable of removing lipophilic drugs by absorption of the drug through their mineral shell and into their core. The particles of the subject invention can also be administered to a patient as controlled release, drug delivery vehicles. Thus, in another aspect, the subject invention concerns a method of delivering pharmacological agents by administering the core-shell particles of the subject invention to a patient in need of such administration.