Retracted: Synthesis, Characterization, and In vitro Studies of PLGA–PEG Nanoparticles for Oral Insulin Delivery

Abstract

Therapeutic proteins and peptides are corresponding to a major area of research in biotechnology companies and current pharmaceutical. Because of their natural instability, the enormous majority of these drugs require parentéral administration. Oral insulin delivery would be a highly attractive alternative process of administration, though it continues to be a mysterious target due to the enzymatic digestion of insulin and low levels of absorption from the gastrointestinal region. Hydrogel polymers can be considered as potential carriers for oral insulin delivery. In particular, a pH responsive hydrogel composed of PLGA-PEG has shown the ability to protect insulin from enzymes in the gastric environment and release in small intestines. However, this material has not shown similar potential for oral protein delivery of further model drugs. To date, the unique interaction between PLGA-PEG and insulin, as a potential drug for oral delivery, is not completely understood. The focus of this research is synthetization and characterization of hydrogels PLGA-PEG insulin nanoparticles and also pH sensitivity of insulin nanoparticles was investigated.

Functionalizing PLGA and PLGA Derivatives for Drug Delivery and Tissue Regeneration Applications

“…[58] ROP has been used to produce PLGA-PEG copolymers through the reaction of lactide, glycolide, and monomethoxy-PEG. [59] The carbodiimide chemistry can also be applied to produce this copolymer, reacting acid-terminated PLGA and the heterobifunctional amine-PEGcarboxyl. [60] Basically, the process consists on the activation of the carboxyl groups of PLGA using a coupling agent and further reaction of the activated PLGA with the amine-PEGcarboxyl polymer, which may be conducted in the presence of N,N-diisopropylethylamine if the desalting of the terminal PEG amine group is needed.…”

Delivering Natural Products and Biotherapeutics to Improve Drug Efficacy

“…However, it is highly challenging to deliver insulin using this approach for a number of reasons, including pH inactivation, harsh chemicals in the digestive tract, enzymatic and cellular barriers [68]. All these can lead to very low insulin bioavailability (<1%) [69]. Recent studies have been carried out using liposomes, microspheres and microemulsions to increase the bioavailability of insulin when it is administered orally.…”

“…Recent studies have been carried out using liposomes, microspheres and microemulsions to increase the bioavailability of insulin when it is administered orally. Encapsulation of proteins like insulin in such vehicles will protect them from the harsh stomach environment [69]. In terms of inhaled insulin, the lungs have been targeted for insulin delivery due to the large surface area (100 m 2 ), and the onset of action following inhalation [70].…”

The Ins and Outs of Nanoparticle Technology in Neurodegenerative Diseases and Cancer

“…PLGA-PEG were also studied for the oral delivery of insulin avoiding thus parenteral administration [72] which may represent a quality-life improvement for patients. This is particularly crucial for the delivery of peptides.…”