A sustainable thermochemical conversion of animal biomass to N-heterocycles

The production of high-valued organonitrogen chemicals,especially N-heterocycles,requires artificial N_(2)fixation accompanied by the consumption of fossil resources.To avoid the use of these energy-and resource-intensive processes,we develop a sustainable strategy to convert nitrogen-rich animal biomass into N-heterocycles through a thermochemical conversion process(TCP)under atmospheric pressure.A high percentage of N-heterocycles(87.51%)were obtained after the TCP of bovine skin due to the abundance of nitrogen-containing amino acids(e.g.,glycine,proline,and L-hydroxyproline).Animal biomass with more diverse amino acid composition(e.g.,muscles)yielded higher concentrations of amines/amides and nitriles after TCP.In addition,by introducing catalysts(KOH for pyrrole and Al_(2)O_(3)for cyclo-Gly-Pro)to TCP,the production quantities of pyrrole and cyclo-Gly-Pro increased to 30.79 mg g^(-1)and 38.88 mg g^(-1),respectively.This approach can be used to convert the significant animal biomass waste generated annually from animal culls into valued organonitrogen chemicals while circumventing NH3-dependent and petro-chemical-dependent synthesis routes.

A biomimetic and pH-sensitive polymeric micelle as carrier for paclitaxel delivery

As nano-scale drug delivery systems,smart micelles that are sensitive to specific biological environment and allowed for target site-triggered drug release by reversible stabilization of micelle structure are attractive.In this work,a biocompatible and pH-sensitive copolymer is synthesized through bridging poly(2-methacryloyloxyethyl phosphorylcholine)(PMPC)block and poly(D,L-lactide)(PLA)block by a benzoyl imine linkage(Blink).Biomimetic micelles with excellent biocompatibility based on such PLA-Blink-PMPC copolymer are prepared as carriers for paclitaxel(PTX)delivery.Due to the rapid breakage of the benzoyl imine linkage under acidic condition,the micelle structure is disrupted with accelerated PTX release.Such pH-sensitive triggered drug release behavior in synchronization with acidic conditions at tumor site is helpful for improving the utilization of drug and facilitating antitumor efficacy.These micelles can be used as promising drug delivery systems due to their biocompatible and smart properties.

A fully absorbable biomimetic polymeric micelle loaded with cisplatin as drug carrier for cancer therapy

cis-dichlorodiammineplatinum(II)(CDDP)-loaded polymeric micelles for cancer therapy have been developed to reduce the serious side effects of cisplatin CDDP.Herein,polymeric micelles incorporated with cisplatin are prepared based on the complexation between CDDP and hydrophilic poly(L-glutamic acid)-b-poly(2-methacryloyloxyethyl phosphorylcholine)(PLG-b-PMPC)diblock copolymers.These CDDP-loaded micelles possess an average size of 91nm with narrow distribution,providing remarkable stability in media containing proteins.The release of CDDP from the micelles is faster at pH 5.0 and pH 6.0 than that at pH 7.4 and in a sustained manner without initial burst release.In addition,there is almost no difference in cellular uptake between these CDDP-loaded micelles and free CDDP.Moreover,in vitro cytotoxicity test shows they possess high efficacy to kill 4T1 cells as compared with free drug.Thus,PLG-b-PMPC copolymer might be a promising carrier for CDDP incorporating in cancer therapy.