Effect of the linear aliphatic amine functionalization on in vitro transfection efficiency of chitosan nanoparticles

Chitosan-based biomaterials for the treatment of bone disorders

Bone is an alive and dynamic organ that is well-differentiated and originated from mesenchymal tissues. Bone undergoes continuous remodeling during the lifetime of an individual. Although knowledge regarding bones and their disorders has been constantly growing, much attention has been devoted to effective treatments that can be used, both from materials and medical performance points of view. Polymers derived from natural sources, for example polysaccharides, are generally biocompatible and are therefore considered excellent candidates for various biomedical applications. This review outlines the development of chitosan-based biomaterials for the treatment of bone disorders including bone fracture, osteoporosis, osteoarthritis, arthritis rheumatoid, and osteosarcoma. Different examples of chitosan-based formulations in the form of gels, micro/nanoparticles, and films are discussed herein. The work also reviews recent patents and important developments related to the use of chitosan in the treatment of bone disorders. Although most of the cited research was accomplished before reaching the clinical application level, this manuscript summarizes the latest achievements within chitosan-based biomaterials used for the treatment of bone disorders and provides perspectives for future scientific activities.

Relationship between phosphorylamine-modification and molecular weight on transfection efficiency of chitosan

The aim of this study is both to design the chitosan (Chi) nanoparticles with different M_w containing the phosphoester bonds and increase their amino function for the transfection. The phosphorylamine-modification of Chi and depolymerized Chi (DChi) was realized using o-phosphorylethanolamine (o-PEA) and characterized, for the first time. The nanoparticles (nMChi and nMDChi) were prepared by ionic gelation and their particle size, polydispersity index (PDI), zeta potential, stability, gene binding capacity and cytotoxicity were examined. The effects of the M_w of Chi on the cytotoxicity, gene binding capacity, and in vitro transfection efficiency of the nanoparticles on Human Embryonic Kidney 293 (HEK293) cells were also examined. Green Fluorescent Protein Circular Plasmid DNA (pEGFN1) loaded nanoparticles (gnMChi and gnMDChi) were used in the transfection. This study showed that the M_w of phosphorylamine-modified Chi significantly affected the characteristics, cytotoxicity, gene binding capacity and transfection efficiency of the nanoparticles.

Potential of chitosan/alginate nanoparticles as a non-viral vector for gene delivery: Formulation and optimization using D-optimal design

Chitosan/alginate (Chi/Alg) nanoparticles as a non-viral vector for the Smad4 encoding plasmid were optimized utilizing D-optimal design based on the nanoparticles/plasmid ratio, Chi/Alg MW, and preparation method type. Following the optimization and validation of the best formula, morphology studies and FTIR measurements were performed to evaluate the optimized Chi/Alg/S NPs. Toxicity (MTT assay) and transfection studies were performed for the best formula in comparison with Lipofectamine 2000, and Polyethyleneimine (PEI) and evaluated using Green Fluorescence Protein (GFP) assay, Flow cytometry, and RT-PCR. The model predicted a particle size of 111 nm, loading efficacy (LE) of 43%, cumulative release (CMR) of 39%, the ζ-potential of +50 mV, and PDI of 0.13. The predicted point condition was as follows: NP ratio = 13, Chi/Alg MW ratio = 2.35, and preparation method type = 1. Microscopic findings revealed that the shape of nanoparticles was spherical. The Chi/Alg/S nanoparticles showed no toxicity and transfection efficacy of 29.9% was observed in comparison with Lipofectamine (35.5%) and PEI (30.9%).

Attachment and in vitro transfection efficiency of an anti-rabies Chitosan-DNA nanoparticle vaccine

In Mexico, urban rabies has been reduced during the last decade thanks to intensive canine control and vaccination campaigns; however, rabies transmitted by wild animals, especially by bats, has been increasing due to vampire bats feeding on livestock. Vampire bat populations has been controlled by culling with vampiricides, reducing indiscriminately other bat species. Hence, bat vaccination for rabies offers an alternative for culling. Nevertheless, available rabies vaccines are not suitable for their use in wildlife from emerging countries. This project presents an alternative for the use of plasmid vaccines using bio-nanotechnology, to create low-cost and accessible vaccines. To accomplish this goal, chitosan nanoparticles were synthesized by ionic gelation and conjugated by coacervation with a pDNA rabies vaccine to test their attachment efficiency. Also, the conjugate was functionalized with Protoporphyrin IX and Folic acid as biomarkers. The nanoparticles complex was characterized by ultraviolet visible spectroscopy, infrared spectroscopy, transmission electron microscopy, dynamic light scattering, and the Z potential was obtained. In vitro tests were performed on cell viability and transfection. The nanoparticles possessed a low polydispersity, a mean size of 118.5 ± 13.6 nm and a Z potential of 17.3 mV. The attachment efficiency was of 100% independent of pDNA added. In contrast to functionalized nanoparticles which showed a max attachment efficiency of 99.6% dependent of pDNA concentration and the method of functionalization. The conjugate did not influence the viability and they improved the transfection efficiency. Results suggest that these nanoparticles are easy to prepare, inexpensive, and exhibit potential for plasmid delivery as it improves transfection efficiency of pDNA vaccines.

Chitosan nanoparticles based on their derivatives as antioxidant and antibacterial additives for active bioplastic packaging

Chitosan nanoparticles (CSNPs) based on their different derivatives were proposed as antioxidant and antimicrobial additives for active bioplastic packaging. Chitosan was modified with polyethylene glycol methyl ether methacrylate (PEGMA), stearyl methacrylate (SMA) and deoxycholic acid (DC) using radiation-induced graft polymerization and chemical conjugation. The modified CSNPs-g-pPEGMA, CSNPs-g-pSMA and CSNPs-DC self-assembled into nanoparticles with the size in the range of 25-60 nm. The CSNPs-DC derivative has superior antioxidant activity and the CSNPs-g-pSMA derivative exhibited outstanding antibacterial activity against growth of E.coli (95.33 %). All modified CSNPs showed their capacities to inhibit S.aureus bacterial growth (>98 %). PLA packaging films containing CSNPs-g-pSMA inhibited the growth of natural microorganism on bread slices. Different chemical functions of the CSNPs derivatives provided different gas permeability and mechanical properties of the PLA films. The CSNPs derivatives would be promising antioxidant and antimicrobial additives for bioplastics to be further used as bio-based active food packaging.

Chitosan-Based Nanocomposites for Glyphosate Detection Using Surface Plasmon Resonance Sensor

This article describes an optical method based on the association of surface plasmon resonance (SPR) with chitosan (CS) film and its nanocomposites, including zinc oxide (ZnO) or graphene oxide (GO) for glyphosate detection. CS and CS/ZnO or CS/GO thin films were deposited on an Au chip using the spin coating technique. The characterization, morphology, and composition of these films were performed by Fourier-transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and contact angle technique. Sensor preparation conditions including the cross-linking and mobile phase (pH and salinity) were investigated and thoroughly optimized. Results showed that the CS/ZnO thin-film composite provides the highest sensitivity for glyphosate sensing with a low detection limit of 8 nM and with high reproducibility. From the Langmuir-type adsorption model and the effect of ionic strength, the adsorption mechanisms of glyphosate could be controlled by electrostatic and steric interaction with possible formation of 1:1 outer-sphere surface complexes. The selectivity of the optical method was investigated with respect to the sorption of glyphosate metabolite (aminomethylphosphonic acid) (AMPA), glufosinate, and one of the glufonisate metabolites (3-methyl-phosphinico-propionic acid) (MPPA). Results showed that the SPR sensor offers a very good selectivity for glyphosate, but the competition of other molecules could still occur in aqueous systems.

Ginger essential oil-based microencapsulation as an efficient delivery system for the improvement of Jujube (Ziziphus jujuba Mill.) fruit quality

Microencapsulation of Zingiber officinale essential oil (EO) in polysaccharide, chitosan (CH) and sodium carboxymethyl cellulose (CMC) based on the electrostatic interaction between charged polysaccharides at pH 3.0 in dual delivery system. Ratio variations of CH and CMC in microencapsulation were studied at 1:2, 2:1 and 1:1. This study aimed to evaluate the influence of the encapsulating materials combination on freeze-dried EO powders and to present the mechanisms for loading and releasing EO involved in the preparation of CH/CMC microcapsules. The spectroscopy analysis, physical properties, microstructural, encapsulation efficiency and EO release behavior in obtained EO microparticles were evaluated by using the analysis of fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and gas chromatography mass spectrometry (GC-MS), respectively. Afterwards, the above prepared microcapsules were applied on winter jujube fruit (Ziziphus jujuba Mill.) preservation. Results demonstrated that both the microstructure and stability of microencapsulation were improved in delivery system loading with CH and CMC (1:1) with the encapsulation efficiency of 88.50%, compared to other ratios of CH and CMC (1:2 and 2:1). Furthermore, the microencapsulation had a capacity to control and reduce the EO release, therefore the morphological and sensory quality of jujube fruits in EO delivery system during storage was enhanced significantly (P < 0.05), in comparison to control. Results revealed that the microparticles produced with CH and CMC (1:1) was considered to present better characteristics of microstructure, encapsulation efficiency, as well as to maintain higher nutritional quality for jujube fruit. Thus, EO microencapsulation loaded in CH/CMC-based dual delivery system has potential application and developmental value prospects in food industries.

Modified chitosan-based nanoadjuvants enhance immunogenicity of protein antigens after mucosal vaccination

Nasal vaccination is considered to be an effective and convenient way of increasing immune responses both systemically and locally. Although various nanovaccine carriers have been introduced as potential immune adjuvants, further improvements are still needed before they can be taken to clinical usage. Chitosan-based nanovaccine carriers are one of the most widely studiedadjuvants, owing to the abilityof chitosan toopen tight junctions between nasal epithelial cells and enhance particle uptake as well as its inherent immune activating role. In present study, bovine serum albumin (BSA) loaded nanoparticles were prepared using novel aminated (aChi) and aminated plus thiolated chitosan (atChi) polymers, to further enhance mucoadhesiveness and adjuvanticity of the vaccine system by improving electrostatic interactions of polymers with negatively charged glycoproteins. Nanocarriers with optimum size and surface charge, high encapsulation efficiency of model antigen and good stability were developed. Negligible toxicity was observed in Calu-3 and A549 cell lines. In vivo studies, revealed high levels of systemic antibodies (IgG, IgG₁ and IgG_2a) throughout the study and presence of sIgA in vaginal washes showed that common mucosal system was successfully stimulated. Cytokine levels indicated a mixed Th1/Th2 immune response. A shift towards cellular immune responses was observed after nasal immunisation with antigen loaded nanoparticle formulations. These nanoparticles exhibit great potential for nasal application of vaccines.