Loaded Poly L-lactic Acid Research Articles

Retraction Note: RGD peptide-pegylated PLLA nanoparticles containing epirubicin hydrochloride exhibit receptor-dependent tumor trafficking in vitro and in vivo.

Purpose A novel hydrophilic conjugate of arginine-glycine-aspartic acid (RGD) and polyethylene glycol (PEG), i.e., RGD-PEGMw (MW = 300, 600, 1000 or 4000), was synthesized and employed in epirubicin (EPI) loaded poly L-lactic acid (PLLA) nanoparticles (NPs) to improve its tumor targeting effect.

Functional nerve cuff electrode with controllable anti-inflammatory drug loading and release by biodegradable nanofibers and hydrogel deposition

This paper demonstrates a polyimide nerve cuff electrode with a controllable drug loading/release function for stable recording of peripheral nerve signals and stimulation and minimizing inflammation. For control of anti-inflammatory drug loading/release, dexamethasone (DEX)-loaded poly L-lactic acid (PLLA) and/or poly lactic-co-glycol acid (PLGA) nanofibers were deposited on a functional nerve cuff electrode by the electro-spinning method, which can control the weight of DEX loading on the functional nerve cuff electrode. Then, UV patternable polyethylene glycol (PEG) was coated on the functional nerve cuff with DEX-loaded nanofibers for the acceleration of the release rate of the drug. Through high performance liquid chromatography (HPLC), DEX release rates were increased from 16 to 28% (PLLA-loaded nanofibers) and from 68 to 87% (PLGA-loaded nanofibers) due to the increased diffusion rate of DEX after 28 days, respectively. In addition, the functional nerve cuff electrode was electro-polymerized with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) as a conductive polymer in order to recover the decreased electrical properties caused by PEG patterning. The impedance measured at 1kHz was 342Ωmm2, which was extremely lower than the value of 1046Ωmm2 of PEG-patterned cuff electrodes. Through the acute ex-vivo test of SD rat's sciatic nerve, the functional nerve cuff electrode with PEDOT:PSS exhibited stable and effective recording of the nerve's signals despite PEG patterning.

RGD Peptide-Pegylated PLLA Nanoparticles Containing Epirubicin Hydrochloride Exhibit Receptor-Dependent Tumor Trafficking In Vitro and In Vivo.

A novel hydrophilic conjugate of arginine-glycine-aspartic acid (RGD) and polyethylene glycol (PEG), i.e., RGD-PEG Mw (M W = 300, 600, 1000 or 4000), was synthesized and employed in epirubicin (EPI) loaded poly L-lactic acid (PLLA) nanoparticles (NPs) to improve its tumor targeting effect. In vitro studies were performed to assess EPI release from NPs in tumor-mimic acidic medium, cytotoxicity and cell cycle assay in HepG2 cells, and cellular uptake kinetics in four types of tumor cells including A375 cells (high integrin receptor expression), HeLa cells (low integrin receptor expression), and metabolic HepG2/SMMC7721 cells. In vivo pharmacodynamics (PD) and pharmacokinetic (PK) studies were determined in a murine ascites tumor model. Cellular uptake kinetics showed integrin receptor-dependent binding and internalization. In vitro release results showed that PLLA and PEG groups retarded EPI release from NPs and promoted drug release amount in acidic medium, which benefited in vivo trafficking to the acidic tumors. In vivo PD and PK studies revealed that RGD-PEG Mw (M W = 600 ~ 1000) improved tumor targeting capacity of NPs by ~2.4-fold, compared to conventional EPI NPs. RGD-PEG Mw (M W = 600 ~ 1000) modified PLLA NPs provide a promising strategy to improve tumor selectivity in cancer treatment.