Synthesis, Characterization, and Functionalization of Chitosan and Gelatin Type B Nanoparticles to Develop Novel Highly Biocompatible Cell-Penetrating Agents

Cristina González,Juan C Cruz,Luis H Reyes,Carolina Muñoz-Camargo

doi:10.3390/iocn2020-07816

Abstract

Nowadays, nanoparticles (NPs) are used to make safe and more effective biomedical technologies for applications in highly targeted therapeutics and drug-delivery vehicles. This helps avoid low cellular penetration and accumulation of the drug in intracellular endosomal compartments that are not of interest to a particular therapy. A way to enhance therapeutic efficiency is through nanoparticle loading systems. This study aims to develop low molecular weight (LMW) and high molecular weight (HMW) chitosan and type B gelatin NPs. To enhance cell penetration, the NPs were interfaced with the translocating peptide Buforin II. The obtained nanobioconjugates were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), confocal microscopy, and transmission electron microscopy (TEM). Their size and surface zeta potential were estimated via DLS (Zetasizer Nano). Furthermore, to visualize their endosomal escape, the NPs were marked with the fluorophore Rhodamine B and imaged with the aid of confocal microscopy. The FTIR results showed bands corresponding to the polymers and Buforin II after conjugation. The average NPs diameters were about 250 nm. The zeta potential of the chitosan NPs approached neutrality, which may be problematic due to low colloidal stability. The gelatin zeta potential of −7 mV was closer to the value required for colloidal stability, i.e., ±10 mV. SEM microscopy of LMW and HMW chitosan NPs showed a round-shape and oval morphology, respectively, while the gelatin NPs had a filamentous morphology. SEM also shows agglomerates of the NPs. TEM microscopy results confirmed the LMW chitosan NPs morphology and showed that their nominal size was 5–10 nm.

Highlights

Nanotechnology has emerged as a powerful route to develop safer and more effective treatments for monitoring, diagnosing, and preventing diseases [1]
Low and high molecular weight chitosan were obtained from Sigma-Aldrich, and Buforin
For three replicas (n = 3), gelatin NPs approached an average diameter of 297 ± 79 nm, while high molecular weight (HMW) chitosan and LMW chitosan NPs of 255 ± 52 nm and 182 ± 62 nm, respectively

Summary

Introduction

Nanotechnology has emerged as a powerful route to develop safer and more effective treatments for monitoring, diagnosing, and preventing diseases [1]. Proceedings 2020, 4, x FOR PEER REVIEW defense mechanisms, only a small number of administered drugs reach the targeted cells in a medical treatment [3]. Some strategies to improve cell-penetrating efficiency include the use of cellpenetrating peptides as well as viral or non-viral vectors, such as nanomaterials [4,5]. Polymeric nanomaterials have shown high effectiveness in protecting and maintaining the stability of peptides, proteins, or DNA during potential degradation processes. Characteristics such as size, surface charge, and morphology can be controlled to define the uptake and internalization pathways and the nanocarriers’ final fate [3,4]

Objectives

Methods

Results