Nowadays the cancer treatments consist of surgery, radiotherapy, and chemotherapy. In spite of some successes of these approaches, they also damage healthy cells and cause toxicity to the patient body. There are also some difficulties in the administration of drug molecules, including aggregation of drug molecules and inefficient distribution, insolubility of drugs, and lack of selectivity. It should be also added another problem that the cell membrane only allows certain structures to pass through. Many studies are being made to invent efficient cancer treatments which directly deliver the drug to the cancerous cells without damaging the healthy cells whereas improve viability and toxicity profiles [1]. Carbon nanostructures are ideal nominees for these goals because they can be functionalized with disparate groups. They can also provide enclosed nanopores to carry the drug molecules [1]. They can also passively cross the cell membranes of many [2].

Among the different carbon nanostructures, the fullerenes have been paid much attention in the nano drug delivery process [3]. Fullerenes not only are antioxidant, neuroprotective and antitumor properties [4], but also they are capable of carrying radiopharmaceuticals and drugs [5]. The low toxicity of fullerenes [6] also plays an important role in the research regarding their use as drug delivery systems and biologic active molecules themselves [[7], [8], [9]]. Recent toxicology studies suggest that nanosized aggregates of fullerene molecules can enter cells and alter their functions, and also cross the blood–brain barrier [10]. However, the fullerenes are hydrophobic which have low solubility in water. This may restrict their potential bio-medical applications. One of the methods to increase their solubility is to attach certain functional groups (such as hydroxyl) to its cage [1,11]. Fullerene derivatives are reported to have remarkable anti-amyloid properties for Alzheimer's disease [12,13]. Many fullerene derivatives can be also used in different pharmaceutical applications. With increasing the water solubility, there is no doubt that fullerene-based delivery systems present many opportunities in disease treatment. However, more tests including toxicological studies must be conducted before clinical examinations [8].

There are many theoretical and simulation studies in the recent years which have paid to the nano drug delivery process using carbon nanostructures. For example, Hilder and Hill [14] simulated encapsulation process of drug molecules into boron nitride (BN), boron carbide (BC), and silicon carbide (SiC) nanotubes and concluded that the BN nanotube is better than other nanotubes which produces less toxicity. Panczyk et al. [15] simulated the release of drug molecules from the carbon nanotube (CNT) which was capped by magnetic nanoparticles using an external magnetic field. Roosta et al. [16] simulated the encapsulation and release of drug molecule in BN nanotubes using C60 molecules (as the realizing agents). Panczyk et al. [17] simulated the adsorption/desorption of drug and dyes molecules on/in the CNT at the environment with different pH values. Recently, Mehrjouei et al. [18] simulated the release of drug molecules from different nanotubes using a silver nanowire. They found that the van der Waals interactions play a major role in the drug delivery process.

In this research, we have investigated the delivery of cis-diamminedichloridoplatinum (II), known as cisplatin, as the anti-cancer drug molecule encapsulated into C240 fullerene with different number of water and carbon dioxide molecules by increasing the temperature. Cisplatin is one of the most famous drug molecules used in the treatment of solid tumors. But, its clinical use is limited because cisplatin has drastic side effects. By developing the nano drug delivery systems, we can now overcome these limitations and specifically direct the cisplatin molecules toward the cancerous tissues [19].

Endohedral fullerenes offer a robust shell that can prevent contact between the body and the entrapped atoms, serving, as a carrier for radionuclides, for instance Ref. [20]. The drug molecule encapsulates in the fullerene and therefore, it has not any effects on the healthy tissues. When the fullerene arrives near the tumor, we can destroy the fullerene wall by increasing its temperature using a laser beam and therefore, the drug releases near the infected tissue.

C240 fullerene is known as a giant fullerene which has more stability than C60 fullerene because of the more heat of formation [21]. Previous studies indicated that C240 fullerene can be a solution for problems faced by medicine and pharmacy [21]. Recent MD study performed on the deformation of different fullerene (C60-C2000) under tension force indicated that C240 fullerene has maximum force capacity among the different fullerenes [22]. Therefore that C240 fullerene is best choice as a nano carrier for the drug molecules.

Experimentally, a surgical method has been used to insert small molecules such as hydrogen and water into C60 or C70 by creation of an opening to the fullerene [[23], [24], [25], [26]]. Then, the opening is closed with the molecules contained within the cage. Theoretically, the confinement of water molecules into nanocavities of fullerenes has been also studied using molecular dynamics (MD) simulations [23,27,28].

The previous studies indicated that nitrogen (N) doping of carbon materials is an effective method to change the mechanical and chemical properties of graphene and CNT [27]. Boron (B) doping is also an effective way to improve carbon materials due to the similarity of size and valence bond of boron

In comparison with the carbon atoms [30,31].The B-doped carbon materials have also some applications in the Li-ion batteries and new carbon composites [32,33]. The experimental

Studies indicated that the silicon nanotubes have more bio-compatibility than the normal CNTs [34]. Recently, the B, N, and Si-doped CNTs have been used for efficient drug delivery using metal nanoparticles and nanowires [35]. More recently, Escobedo-Morales et al. [36] investigated the effect of carbon doping on different properties of BN fullerenes using density functional theory (DFT) computations. Their results showed that the carbon doping decreases the cohesive energy of the fullerenes whereas most of them remain stable. They also showed that the carbon doping enhances the capability of fullerenes to interact with other chemical species. Investigation of the effect of N, B, and N-doping in the fullerene in the drug releasing processes is another target of this work.