The Effect of Lipid Composition on the Liposomal Delivery of Camptothecin Developed by Active Click Loading.

In the present study, we investigated the role of lipid composition of camptothecin (CPT)-loaded liposomes (CPT-Lips) to adjust their residence time, drug distribution, and therefore the toxicities and antitumor activity. The CPT was loaded into liposomes using a click drug loading method, which utilized liposomes preloaded with GSH and then exposed to CPT-maleimide. The method produced CPT-Lips with a high encapsulation efficiency (>95%) and sustained drug release. It is shown that the residence times of CPT-Lips in the body were highly dependent on lipid compositions with an order of non-PEGylated liposomes of unsaturated lipids < non-PEGylated liposomes of saturated lipids < PEGylated liposomes of saturated lipids. Interestingly, the fast clearance of CPT-Lips resulted in significantly decreased toxicities but did not cause a significant decrease in their in vivo antitumor activity. These results suggested that the lipid composition could effectively adjust the residence time of CPT-Lips in the body and further optimize their therapeutic index, which would guide the development of a liposomal formulation of CPT.

Catalytic Oxidative Cleavage of C(OH)-C Bonds in Lignin Model Compounds to Carboxylic Acids by Fe(NO3)3.9H2O/NaI/DMSO.

The secondary C(OH)-C bonds are abundant in biomass such as lignin and cellulose. Thus, selective cleavage of the C(OH)-C bonds into value chemicals attracted much attention. Molecular iodine has received considerable attention as an inexpensive and readily available catalyst to yield the corresponding products in excellent yields with high selectivity, but it is highly corrosive and toxic, making its use somewhat unattractive. In this study, I2 was generated in situ from Fe(NO3)3.9H2O/NaI, which was further combined with Fe(NO3)3.9H2O to catalyze the oxidation process. In the reaction, the H2O molecule from the reaction and Fe(NO3)3.9H2O attacked the phenylglyoxal to form benzaldehyde, which was further oxidized to benzoic acid. Aryl primary and secondary benzylic alcohols from lignin were successfully transformed into aryl carboxylic acids by Fe(NO3)3.9H2O/NaI/DMSO. The catalytic system was green and efficient, avoiding the usage of toxic and corrosive molecular I2. From the experiments, it was clear that the yield of the product from the substrates with an electron-donating group was higher than that of electron-withdrawing substituted substrates, which was similar to the aryl secondary alcohols. Aryl alkyl ketones were also successfully conducted by the Fe(NO3)3.9H2O/NaI/DMSO catalytic system.

[Determination of 19 illegally added chemical ingredients in hair loss prevention cosmetics by ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry].

Cosmetic products for hair loss prevention are often mixed with prohibited substances such as hormones, antibiotics, and forbidden pharmacologically active substances. Although drugs increase the efficacy of cosmetic products, they cause skin irritation and allergic reactions, upon long-term exposure. Given the increasing number of hair loss prevention cosmetics on the market, the need to guarantee product safety calls for efficient and reliable methods to identify illegal ingredients in these products. Chromatography combined with high-resolution mass spectrometry offers the advantages of high resolution and high throughout, thus being a powerful technique for simultaneously detecting illegal ingredients in cosmetics. In this study, an ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF-MS) method for detecting 19 illegal chemical components was established. Combined with the scientific database, a screening platform for hair loss prevention cosmetics was constructed. The effect of extraction solvent was investigated. The chromatographic and mass spectrometry conditions were optimized. Under the optimal conditions, separation was achieved within 20 min on an ACQUITY UPLC BEH C18 column (100 mm×2.1 mm, 1.7 µm). Acetonitrile and 2 mmol/L ammonium formate solution containing 0.05% formic acid were used as mobile phases for gradient elution. The 19 compounds were detected by positive ion electrospray ionization (ESI) in the MSE mode. The chromatographic retention time, precursor ions, product ions of the target analytes, and abundance ratio were collected to construct a screening database with UNIFI software. The 19 compounds were well separated, with good linearity. The limits of detection (LODs) and limits of quantification (LOQs) were 0.025-0.05 µg/g and 0.075-0.15 µg/g, respectively. Hair lotion and shampoo, which are commonly marketed as hair loss prevention cosmetics, were selected as the respective matrices for the recovery experiment. The average recoveries of the 19 compounds ranged from 68.6% to 118.6%, and the relative standard deviations (RSDs) were 0.3%-10.3%. Then, 77 batches of cosmetic samples were detected and screened under the same conditions. The TOF-MS information, including the retention time, ion addition mode, mass-to-charge ratio of the parent ions and fragment ions, as well as the abundance ratio, were compared between the cosmetic samples and the standard MS information with UNIFI software. Finally, two batches of samples that were illegally adulterated with minoxidil and finasteride were identified. The ESI fragmentation pathway of the product ions from minoxidil was also proposed. The matrix matching external standard method was used to determine the amounts of minoxidil and finasteride in the two batches of hair lotion, and they were as high as 60 mg/g and 0.31 mg/g, respectively. This result revealed that multiple chemical components were simultaneously added to hair loss prevention cosmetics. Furthermore, the amount of the illegally added drug was very high, indicating high safety risk for consumers using such cosmetics. The present method has the advantages of simple operation, high sensitivity, and good reproducibility. It can be used for rapid screening and simultaneous quantitative analysis of various illegal chemicals in hair loss prevention cosmetics.