Self-assembled nanomicelles using PLGA–PEG amphiphilic block copolymer for insulin delivery: a physicochemical investigation and determination of CMC values

Abstract

Self-assembled nanomicelles can be used as synthetic biomaterials and colloidal carriers for poorly water-soluble drug delivery systems. Some of these micellar systems have been introduced in clinical trials and showed hopeful results relating to their therapeutic index in patients. Biodegradable nanomicelle was prepared from self-assembling amphiphilic block copolymer composed of poly(DL-lactic-co-glycolic acid) (PLGA) as a core and polyethylene glycol (PEG) as a corona. The PLGA-PEG block copolymer was first synthesized and characterized by FTIR, (1)H NMR, GPC and inherent viscosity measurements. The nanomicelle formed by PLGA-PEG block copolymer in the aqueous solution was characterized by dynamic light scattering, zeta potential, scanning electron microscopy (SEM) and fluorescence excitation and emission spectra of pyrene probe. The critical micelle concentration of obtained nanomicelle was about 0.006 mg/mL, with the size of about 160 nm and the zeta potential of -29 mV. Insulin-loaded PLGA-PEG nanomicelles were prepared by modified dialysis method and the physicochemical parameters of the micelles such as drug content, entrapment efficiency and in vitro drug release were characterized. The results showed that insulin was entrapped into PLGA-PEG nanomicelles with drug loading of 3.9 wt% and entrapment efficiency of 55 wt%. The nanomicelles containing insulin exhibited a controlled release profile. These observations suggested that the PLGA-PEG block copolymers nanomicelles have been prepared by a new synthetic route are potent nanocarrier for poorly water-soluble drugs as insulin.

Triggered insulin release studies of triply responsive supramolecular micelles

“…39,40 In this system, the release of insulin can be achieved by using three different triggers, namely, temperature, glucose, and a competitive guest. For example, certain systems presented for insulin delivery in literature do not have have glucose sensitivity.…”

Phenylboronic acid‐functionalized F127‐oligochitosan conjugate micelles for doxorubicin encapsulation

“…Critical micellar concentration (CMC) of PBA‐CS‐F127 was determined via pyrene fluorescence technique (Ashjari, Khoee, Mahdavian, & Rahmatolahzadeh, 2012). PBA‐CS‐F127 was dissolved into distilled water to form a series of solutions ranging from 1 × 10 −8 to 1 × 10 −4 g/ml.…”

Promises of Nanotherapeutics in Obesity

“…This non-specificity is sometimes not optimal for systemic application but can be overcome by attaching poly(ethylene glycol) (PEG) to their surface which induces a "stealth" property with minimal or no uptake by the reticuloendothelial system [107][108][109]. For example, a block copolymer of poly(Lactideco-glycolide) (PLGA)-PEG tends to form a micelle but requires more chemical synthesis and purification [110,111]. Micelles generally are optimal for the encapsulation of hydrophobic agents, their stability is better than nanoemulsions and liposomes, and the formulation process is also simpler.…”