Preparation, characterization, and in vitro and in vivo investigation of chitosan-coated poly (d,l-lactide-co-glycolide) nanoparticles for intestinal delivery of exendin-4

Abstract

Background: Exendin-4 is an incretin mimetic agent approved for type 2 diabetes treatment. However, the required frequent injections restrict its clinical application. Here, the potential use of chitosan-coated poly (d,l-lactide-co-glycolide) (CS-PLGA) nanoparticles was investigated for intestinal delivery of exendin-4. Methods and results: Nanoparticles were prepared using a modified water-oil-water (w/o/w) emulsion solvent-evaporation method, followed by coating with chitosan. The physical properties, particle size, and cell toxicity of the nanoparticles were examined. The cellular uptake mechanism and transmembrane permeability were performed in Madin-Darby canine kidney-cell monolayers. Furthermore, in vivo intraduodenal administration of exendin-4-loaded nanoparticles was carried out in rats. The PLGA nanoparticle coating with chitosan led to a significant change in zeta potential, from negative to positive, accompanied by an increase in particle size of ∼30 nm. Increases in both the molecular weight and degree of deacetylation of chitosan resulted in an observable increase in zeta potential but no apparent change in the particle size of ∼300 nm. Both unmodified PLGA and chitosan-coated nanoparticles showed only slight cytotoxicity. Use of different temperatures and energy depletion suggested that the cellular uptake of both types of nanoparticles was energy-dependent. Further investigation revealed that the uptake of PLGA nanoparticles occurred via caveolin-mediated endocytosis and that of CS-PLGA nanoparticles involved both macropinocytosis and clathrin-mediated endocytosis, as evidenced by using endocytic inhibitors. However, under all conditions, CS-PLGA nanoparticles showed a greater potential to be transported into cells, as shown by flow cytometry and confocal microscopy. Transmembrane permeability analysis showed that unmodified and modified PLGA nanoparticles could improve the transport of exendin-4 by up to 8.9-and 16.5-fold, respectively, consistent with the evaluation in rats. Conclusion:The chitosan-coated nanoparticles have a higher transport potential over both free drug and unmodified particles, providing support for their potential development as a candidate oral delivery agent for exendin-4.

An Overview of Chitosan Nanoparticles and Its Application in Non-Parenteral Drug Delivery

“…Similar mechanisms occur with chitosan-PLGA NPs, however, due to their positive charge electrostatic interactions occur with the negatively charged cell membrane resulting in a higher P app . The in vivo study revealed higher plasma drug levels and longer retention times of exendin-4 when administered as chitosan-PLGA NP compared to PLGA NP [35]. …”

Engineered nanoparticle bio-conjugates toxicity screening: The xCELLigence cells viability impact

“…14,21,[27][28][29]37 The in vivo animal model provided further toxicity information where 3 out of 9 of the in vivo animal model studies indicated partial nontoxic animal effect, one was toxic while the remaining results recommended ENPBCs as a potential candidate for drug therapy with limited information on toxicity (Table S2). Some of the in vivo ENPBCs toxicity effects demonstrated programmed cell death, causing the release of H 2 S. 29 The ENPBCs that exhibited in vivo nontoxic effect were mostly those that had the therapeutic effects of antibody-drug conjugate, 27 CTAB layers of gold for diagnosing rheumatoid arthritis, 30 surface coating polymeric NPs used for inhibiting cancerous cells 31,[38][39][40][41][42][43][44][45][46][47] and felodipine-loaded polymers for pathological examination of different organs of Wister albino mice 50. The ENPBCs with partial nontoxic effect were chitosan-coated polymers for drug delivery, 49 silver NPs coated polymers that were found localized in various body organs, 48 and drug delivery polymeric NPs for anticancer. 51 The findings indicated limited data and information regarding the regulation of ENPBCs toxicity.…”

“…These varying outcomes are described in Table S2. 24,28,[30][31]38,[44][45][46][47][48][49][50][51] Altogether, more in vivo animal predictive data are needed to validate standard methods for determining the safe applications of ENPBCs in humans.…”

“…The eligible studies were further screened for duplicates and other irrelevant studies. To reduce discrepancies, a clear screening and selection approach was used based on the headings generated in Tables S1 14, and S2 24,[28][29][30][31]38,[44][45][46][47][48][49][50][51] (see Supplementary file 1). Similarly, some findings were further discussed to find a suitable outcome especially for the same studies extracted from conference abstracts and the full published articles.…”

Poly(lactic-co-glycolic) Acid-Chitosan Dual Loaded Nanoparticles for Antiretroviral Nanoformulations

“…Chitosan (CS) has gained attention in the nanomedicine field because it carries a positive charge that can be utilized for cellular and anatomic targeting of NPs [ 12 ]. The electrostatic interactions between positively charged CS NPs and the negatively charged cell surface have been shown to enhance nanoparticle uptake [ 13 – 18 ]. By using a PLGA core in conjunction with a CS shell, both hydrophobic and hydrophilic drugs can be encapsulated within NP.…”