Development of a new micellar anticancer drug: Cationic polymer/vitamin A conjugate covered with hyaluronic acid

PEG Grafted Polymethacrylates Bearing Antioxidants as a New Class of Polymer Conjugates for Application in Cosmetology

The amphiphilic copolymers of poly(ethylene glycol) methyl ether methacrylate (MPEGMA) and alkyne functionalized 2-hydroxyethyl methacrylate (AlHEMA) were synthesized by controlled atom transfer radical polymerization (ATRP). The reactions were carried out using the standard ATRP initiator ethyl α-bromoisobutyrate, (EiBBr) and the “bio”initiator bromoester derivative of 4-n-butylresorcinol (4nBREBr₂). Two substances with antioxidant activity used in cosmetology, (±)-α-lipoic acid (LA) and ferulic acid (FA), were subjected to esterification reactions to introduce azide groups. The “click” reactions between the alkyne contained copolymers and functionalized acids (LA-N₃, FA-N₃) were performed to obtain polymer-antioxidant conjugates (P((HEMA-click-FA)-co-MPEGMA) and P((HEMA-click-LA)-co-MPEGMA)). The conjugation was performed with an efficiency of 20–75%. In vitro experiments in a phosphate buffer saline (PBS) solution at neutral conditions demonstrated that the sufficient release was reached after 2.5 h for FA and 1 h for LA. The rapid release kinetics as well as the polymer carriers, which were applied to regulate the delivery of antioxidant substances, are beneficial in cosmetology.

Double-layered hyaluronic acid/stearic acid-modified polyethyleneimine nanoparticles encapsulating (-)-gossypol: a nanocarrier for chiral anticancer drugs

This study aimed to enhance the water solubility and antitumor efficacy of (-)-gossypol. Polyethyleneimine conjugated with stearic acid (PgS) was used for loading and protecting (-)-gossypol through hydrogen bonding. Double-layered hyaluronic acid (HA)-modified PgS nanoparticles encapsulating (-)-gossypol [(-)-G-PgSHAs] were prepared through a two-step fabrication process. The nanoparticles possessed a uniform spherical shape with a dynamic size of 110.9 ± 2.4 nm, which was determined through transmission electron microscopy and dynamic light scattering analysis. The encapsulation efficiency and drug-loading capacity of (-)-G-PgSHAs were 72.6% ± 3.1% and 9.1% ± 0.42%, respectively. The IR spectra of the samples confirmed the protection effect of hydrogen bonding on the optical activity of the encapsulated (-)-gossypol. (-)-G-PgSHAs exhibited a controlled and tumor-specific release because of the high expression of HAase in the tumor region. The tumor-targeting feature of PgSHAs due to HA-receptor mediation was confirmed by in vitro cell uptake and in vivo near infrared fluorescence imaging. The in vitro test showed that the (-)-G-PgSHAs had similar cytotoxicity to free (-)-gossypol and was smaller than that of the encapsulated (±)-gossypol [(±)-G-PgSHAs]. The in vivo study of the anti-cancer effect of (-)-G-PgSHAs revealed that (-)-G-PgSHAs had a more enhanced tumor-suppression effect and reduced systemic toxicity compared with free (-)-gossypol and (±)-G-PgSHAs (P < 0.05). Therefore, PgSHA was a useful (-)-gossypol nanocarrier that exhibits high biocompatibility, tunable release of drug, and tumor-targeting characteristics for cancer treatment. In addition, this double-layered nanocarrier provided novel strategies for the encapsulation of other chiral drugs.

Multifunctional magnetic nanoparticles modified with polyethylenimine and folic acid for biomedical theranostics

This paper describes the preparation of magnetic nanoparticles modified with polyethylenimine (PEI)-folic acid (PF) conjugate and their potential biomedical applications. Magnetic nanoparticles modified with (3-(2-aminoethylamino)propyltrimethoxysilane) (AEAPS) were first prepared using a ligand exchange method to provide biocompatibility and hydrophilicity, and further conjugated with PF to carry gene and enhance specific uptake into cancer cells. We demonstrated the feasibility of the multifunctional magnetic nanoparticles as contrast agents in magnetic resonance imaging (MRI) and as gene carriers for gene delivery. In vitro results revealed that the cytotoxicity of the multifunctional magnetic nanoparticles was lower compared to that of pristine magnetic nanoparticles. Furthermore, we demonstrated the specific uptake of the magnetic nanoparticles modified with PF to KB cells using WI-38 cells as comparison by confocal microscopy. The PF-modified magnetic nanoparticles can potentially be employed as theranostic nanoplatforms for targeted gene delivery to cancer cells and simultaneous magnetic resonance imaging.