Many particles, such as superparamagnetic nanoparticles, Gr, and ZnO have been studied for their applications in medicine. The most exciting and controllable particles are iron oxide nanoparticles, which can be delivered using external magnetic forces. Previous studies have already targeted superparamagnetic iron oxide nanoparticles (SPIONs) by using external magnets. These particles are based on a core of iron oxides and are coated with biocompatible materials, such as drugs, proteins, or plasmids. Therefore, SPIONs have been widely used in biomedicine. However, SPIONs are somewhat limited in biomedical applications. For example, SPIONs functionalized with antibodies against surface receptors bind to cell membranes and induces hyperthermia, damaging the cell membrane locally; by contrast, SPIONs exhibits slower degradation in cells, enhancing its applicability to tumor cells [1].

These new carriers have been the subject of much research. The purpose of this paper is briefly to review relationship among Gr, ZnO, and ZnC₂O₄ and subsequently to mention induced toxicity of SPIONs, Gr oxide, and ZnO. In this paper, essentially intrinsic properties of villous ZnC₂O₄ are explained and interpret as a potential candidate in nanomedicine.

SPIONs are small synthetic Fe₂O₃ or F₃O₄ particles with a core size of <10 nm and an organic or inorganic coating. Their surface modification by organic molecules fulfills different goals. First, this modification stabilizes nanoparticles with a pH of approximately 7.4 and a high salt concentration. Second, it provides functional groups at the surface for further derivatization. Finally, it avoids immediate uptake by the reticulendothelial system [1].

Researchers have also paid considerable attention to SPIONs for their in vitro applications in medical diagnostics, such as genetics research and technologies based on the immune magnetic separation of cells, proteins, DNA and RNA, bacteria, viruses, and other biomolecules. Additionally, SPIONs are useful in in vivo applications, and can be utilized as delivery systems for drugs, genes, and radionuclides. By applying an external magnetic field, the concentration of SPIONs can be increased at a local site. SPION-containing solutions act as contrast agents in magnetic resonance imaging and are routinely applied in the field of diagnostic imaging.

Graphene (Gr) derivatives have been widely investigated. Gr-based materials exhibit two-dimensional (2D) plane structures. Gr can be oxidized, reduced, and transformed into Gr oxide (GO) particles. The structure of reduced Gr oxide (rGO) is nearly the same as that of Gr. ZnO particles are synthesized using direct precipitation, sol-gel, adrothermal [2], or bilayer fluxing [3] methods. ZnO can also be prepared from zinc oxalate (ZnC₂O₄) through heating.

ZnC₂O₄ can be synthesized using various methods, such as the simple precipitation sol-gel method [4] or the solgel method using rGO and ZnO [5,6]. Research has described the relationships among rGO, ZnO, and ZnC₂O₄, and has found that ZnC₂O₄ can be regarded as the derivative of rGO and ZnO. Moreover, it can be transformed in versus.

In the domain of nanomedicine, GO is currently applied in delivery systems, tissue engineering, cancer therapy, and imaging; however, GO induces cytotoxicity [7]. The toxicity of Gr and GO is dependent on its physicochemical properties [8], the exposure environment, and the mode of interaction with cells. The cytotoxicity of GO damages the cell plasma membrane, and the interaction of GO with toll-like receptors may induce macrophage necrosis [9].

ZnO nanoparticles selectively induce apoptosis in cancer cells, which is likely to be mediated by reactive oxygen species through the p53 pathway. Most anticancer drugs trigger apoptosis through this pathway. ZnO nanoparticles also provide preliminary guidance for the development of liver cancer therapy [10]. The cytotoxicity of ZnO Involves generation of reactive oxygen species (ROS) or induction of apoptosis [11].

ZnC₂O₄ typically exhibits an elongated tetrahedral geometry with two basic structures, α-ZnC₂O₄ and β- ZnC₂O₄ [12]. The crystal form of α-ZnC₂O₄ is triclinic. Adjacent metal ions are linked in a one-dimensional chain structure, but interchain metal ions are linked in a 3D network structure through hydrogen bonding. By contrast, the structure of β-ZnC₂O₄ is determined by its cation and anion chains (i.e., C₂O₄–Zn–C₂O₄–Zn and Zn–O). The octahedral structure formed by zinc cobonding is the optimal location for the insertion of impurities.

ZnC₂O₄ is slightly soluble in water; it is also slightly soluble in a glucose solution in the human body. Even after 3 h, its wt% slightly increases to a 2–3 wt% level. Therefore, it can be slowly degraded in solution.

In ZnC₂O₄, the levels of carbon and zinc determine C–H bonding, and the counter ion effect may play a role in supersaturation. This effect produces the driving force that attracts carbon. In ZnC₂O₄ synthesized from rGO and ZnO, carbon is attracted to the open structure between the cation and anion chains, and in the ZnC₂O₄ crystals, each zinc ion coordinates with six oxygen atoms to form an octahedral structure that readily accommodates and sustains impurities. Consequently, the structure is the optimal location for the insertion of impurities. Zinc is an integral part of more than 200 enzymes in the human body. Most of these zinc-containing enzymes include zinc ions and a bioligand mixed structure. The zinc activates catalytic functions and acts as a regulator. Therefore, several studies have focused on the design of active centers and the synthesis of complexes.

Nanoparticles precoated with corona proteins have been demonstrated to exhibit reduced cytotoxicity; albumin is one of the plasma proteins that bind to nanoparticles [11]. Villous ZnC₂O₄ exhibits a less harmful structure, and can be used as a template for nucleation and surface-coated materials.

The relationships among Gr, ZnO, and ZnC₂O₄ can be understood from the synthesis perspective. Phase-refined materials of ZnC₂O₄ have potential applications in nanomedicine, and villous ZnC₂O₄ synthesized using solgel and laser methods has a structure different from the elongated tetrahedral α structure of ZnC₂O₄ produced using conventional methods. Phase-refined villous ZnC₂O₄ exhibits excellent properties, including an open and noncytotoxic structure, solubility, adherence, and affinity. These properties demonstrate that villous ZnC₂O₄ has potential uses in nanomedicine.

Figure1: Percentage of inhibition verses conc in log (μg/ml) of different extracts and Ascorbic Acid.

Note: “+” present; “-” absent

Table1: Classes of phytochemicals present in Caragana jubata.

Note: (-) absent. ± Standard Deviation (SD), n = 3.aWell size was 6mm, Inhibition zone diameter (mm)

Table 2: Zones of growth inhibition (mm) by the extracts against six bacteria.

Note: ± SD (n = 3).

Table 3: Brine shrimp mortality of extracts

Note ±: SD, n = 3.

Table 4: DPPH scavenging free radical of extracts.