The main aim of this review is to assess the potential use of natural cross-linking agents, such as genipin, citric acid, tannic acid, epigallocatechin gallate, and vanillin in preparing chemically cross-linked hydrogels for the biomedical, pharmaceutical, and cosmetic industries. Chemical cross-linking is one of the most important methods that is commonly used to form mechanically strong hydrogels based on biopolymers, such as alginates, chitosan, hyaluronic acid, collagen, gelatin, and fibroin. Moreover, the properties of natural cross-linking agents and their advantages and disadvantages are compared relative to their commonly known synthetic cross-linking counterparts. Nowadays, advanced technologies can facilitate the acquisition of high-purity biomaterials from unreacted components with no additional purification steps. However, while planning and designing a chemical process, energy and water consumption should be limited in order to reduce the risks associated with global warming. However, many synthetic cross-linking agents, such as N,N′-methylenebisacrylamide, ethylene glycol dimethacrylate, poly (ethylene glycol) diacrylates, epichlorohydrin, and glutaraldehyde, are harmful to both humans and the environment. One solution to this problem could be the use of bio-cross-linking agents obtained from natural resources, which would eliminate their toxic effects and ensure the safety for humans and the environment.

The role of oxidative stress in activity of anticancer thiosemicarbazones The role of oxidative stress in activity of anticancer thiosemicarbazones

Ionic liquids are viewed as green media for many engineering applications and exhibit exceptional properties, including negligible vapor pressure, null flammability, wide liquid range, and high thermal and chemical stabilities. We present new thermophysical properties of 1-alkyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imides ([C_nC₁pyr][NTf₂] with n = 3, 4) for future application them as heat-transfer media. The speed of sound was measured at pressures up to 100 MPa and at temperatures from 293 K to 318 K. The pρT, pC_pT data, and derived thermophysical properties were determined using the acoustic method. TGA of [C_nC₁pyr][NTf₂] and cytotoxicity of [C_nC₁pyr][NTf₂] and their imidazolium counterparts ([C_nC₁im][NTf₂]) are investigated. The physicochemical properties of [C_nC₁pyr][NTf₂] are compared with those of [C_nC₁im][NTf₂] and commercial heat-transfer fluids (Therminol VP-1, Therminol 66, Marlotherm SH). [C₃C₁pyr][NTf₂] and [C₄C₁pyr][NTf₂] have a wide liquid range of ∼480 K and high decomposition onset temperatures of 771 and 776 K, respectively. [C_nC₁pyr][NTf₂] exhibit high energy storage density of ∼1.98 MJ m^–3 K^–1, which is slightly dependent on temperature and pressure. The thermal conductivity of [C_nC₁pyr][NTf₂] is comparable to that of commercial heat-transfer fluids. [C_nC₁pyr][NTf₂] have lower toxicity for normal human dermal fibroblast cells than [C_nC₁im][NTf₂]. Thus, [C_nC₁pyr][NTf₂] are promising heat-transfer fluid candidates.