Synthesis of raloxifene–chitosan conjugate: A novel chitosan derivative as a potential targeting vehicle

Effect of Soybean Oil on the Improvement of the Functionality of Edible Membrane-Type Food Packaging Films Based on Caseinate-Carboxymethyl Chitosan Compositions

Edible film biopolymers are gaining attention to tackle problems of plastic waste and food safety to alleviate environmental problems associated with plastic products in food packaging. In this study, caseinate-carboxymethyl chitosan (CA-CMCH) composite films were made with the incorporation of soybean oil (SO) using a casting technique. The influence of different soybean oil concentrations at 0, 0.5, and 1% (w/w) on physical, mechanical, barrier, and surface characteristics of films composed of caseinate-carboxymethyl chitosan (CA-CMCH) was evaluated. The brightest film (L* value of 95.95 ± 0.30) was obtained with the edible film made from the control group of samples with sodium caseinate (NaCA-100; 100% NaCA). The results also indicated that samples with 1% SO in NaCA-75 and CaCA-75 had lower water vapor permeability (WVP), while those with NaCA-50 and CaCA-50 showed higher values of WVP. For mechanical properties, this study found that incorporating soybean oil into the caseinate-carboxymethyl (CA-CMCH) composite films led to an enhancement of both tensile strength and elongation at break. The morphological structures, determined using SEM, of control and composite films showed compact and homogenous surfaces. Overall, the addition of soybean oil contributed to the improvement of the functional properties of the edible films, offering potential solutions to the environmental issues associated with plastic packaging and enhancing the safety and performance of food packaging.

Recent advances in carboxymethyl chitosan-based materials for biomedical applications

Chitosan (CS) and its derivatives have been applied extensively in the biomedical field owing to advantageous characteristics including biodegradability, biocompatibility, antibacterial activity and adhesive properties. The low solubility of CS at physiological pH limits its use in systems requiring higher dissolving ability and a suitable drug release rate. Besides, CS can result in fast drug release because of its high swelling degree and rapid water absorption in aqueous media. As a water-soluble derivative of CS, carboxymethyl chitosan (CMC) has certain improved properties, rendering it a more suitable candidate for wound healing, drug delivery and tissue engineering applications. This review will focus on the antibacterial, anticancer and antitumor, antioxidant and antifungal bioactivities of CMC and the most recently described applications of CMC in wound healing, drug delivery, tissue engineering, bioimaging and cosmetics.

Novel Chitosan Derivatives and Their Multifaceted Biological Applications

Chitosan is a rather attractive material, especially because of its bio-origins as well as generation from exoskeletal waste. As the mantle has been effectively transferred from chitin to chitosan, so has it been extrapolated to in-house synthesized novel chitosan derivatives. This review comprehensively lists the available novel chitosan derivatives (ChDs) and summarizes their biological applications. The fact that chitosan derivatives do comprise multifaceted biological applications is attested by the voluminous reports on their varied contributions. However, this review points out to the fact that there has been selective focus on bio functions such as antifungal, antioxidant, antibacterial, whereas other biomedical applications and antiviral applications remain relatively less explored. With their current functionality record, there is definitely no doubt that the plethora of synthesized ChDs will have a profound impact on the unexplored biological aspects. This review points out this lacuna as room for future exploration.

Chitosan-Raloxifene nanoparticle containing doxorubicin as a new double-effect targeting vehicle for breast cancer therapy

BACKGROUND

treatment of breast cancer as one of the most common cancers in the world remains an important area of drug development based on nanoparticulate systems. Effective targeted therapy of affected cells based on ligand conjugate biocompatible polymeric nanoparticles is an attractive perspective in this context.

OBJECTIVE

In this study, a novel double effect nanoparticle based on Chitosan-Raloxifene conjugate was prepared for adjuvant therapy (hormone and chemo therapy) and drug targeting to breast cancer cells via estrogen receptor (ER).

METHODS

Chitosan-raloxifene conjugate was synthesized. Related nanoparticles containing doxorubicin (DOX) were prepared and characterized. Experimental design study was performed to determine the optimum levels of variables in the preparation of nanoparticle. Drug loading, release, nanoparticle stability, and the effect of nanoparticles on cell viability were evaluated. Further, inhibition tests were performed to demonstrate that the function of these novel nanoparticles is mediated via ER.

RESULTS

Chitosan-raloxifene conjugate was successfully synthesized. The prepared nanoparticles showed sizes within 25-35 nm, more than 95% drug loading, about 60% of drug release and desired stability after 24 h. XTT assay on MCF-7 cell line illustrated that these nanoparticles could inhibit the cellular growth up to 60%. The results from inhibition tests revealed that prepared nanoparticles can inhibit cell growth via ER blocking.

CONCLUSION

This study introduced chitosan-raloxifene nanoparticles containing doxorubicin as a novel targeting agent for adjuvant therapy of breast cancer. Graphical abstract.

Experimental design data for the zinc ions adsorption based on mesoporous modified chitosan using central composite design method

In the present study, new generation of silica-based mesoporous adsorbents were introduced for the removal of heavy metals with the aim of developing new adsorption technologies in water treatment. The magnetic nanoadsorbent, prepared by modification of SBA-15 with [3-(2-Aminoethylamino) propyl] trimethoxysilane (AEAPTMS)-functionalized chitosan, was applied for the removal of Zn²⁺ from aqueous solution. The synthesized Fe₂O₃@SBA-15-CS-AEAPTMS nanoadsorbent was thoroughly characterized using XRD, TEM, FTIR and BET analysis. In order to determine the optimum condition of Zn²⁺ adsorption on Fe₂O₃@SBA-15-CS-AEAPTMS (3 ml), the experiments were performed based on central composite design in a response surface methodology method. The obtained results were further studied using adsorption kinetic, isotherm and thermodynamic relations which revealed that Zn²⁺ adsorption was spontaneous and endothermic with enhanced adsorption efficiency achieved for higher contents of functional groups. In addition, according to the results, the adsorption process was best conformed to Langmuir isotherm (with R² > 0.99 and q_max = 107.21 mg g^-1) and pseudo second-order kinetic model (with R² > 0.999). The values of standard entropy (DS°) and activation energy (E_a) reduced as the initial concentration was increased and the dominant mechanism was found to be chemisorption.

Thiolated methylated dimethylaminobenzyl chitosan: A novel chitosan derivative as a potential delivery vehicle

Chitosan is a natural mucoadhesive, biodegradable, biocompatible and nontoxic polymer which has been used in pharmaceutical industry for a lot of purposes such as dissolution enhancing, absorption enhancing, sustained releasing and protein, gene or drug delivery. Two major disadvantages of chitosan are poor solubility in physiological pH and low efficiency for protein and gene delivery. In this study thiolated methylated N-(4-N,N-dimethylaminobenzyl) chitosan was prepared for the first time in order to improve the solubility and delivery properties of chitosan. This novel chitosan derivative was characterized using ¹H NMR, Ellman test, TGA and Zetasizer. Cell toxicity studies were performed on Human Embryonic Kidney 293 (Hek293) cell line using XTT method, to investigate the potential effect of this new derivative on cell viability. ¹H NMR results showed that all substitution reactions were successfully carried out. Zeta potential of new derivative at acidic and physiological pHs was greater than chitosan and it revealed an increase in solubility of the derivative. Furthermore, it had no significant cytotoxicity against Hek293 cell line in comparison to chitosan. These findings confirm that this new derivative can be introduced as a suitable compound for biomedical purposes.

Preparation and characterization of chitosan microparticles for immunoaffinity extraction and determination of enrofloxacin

The use of chitosan microparticles as chromatographic support has received much attention. In this study, the effects of process parameters, namely, chitosan molecular weight, chitosan concentration, molar ratio of amino group to aldehyde group, volume ratio of water to oil phase and stirring speed on the size and size distribution of chitosan microparticles and their application for immunoaffinity extraction were extensively investigated. Size distribution analysis indicated that the average diameter of the microparticles was 124μm with Span value of 1.1. The obtained microparticles exhibited low non-specific adsorption and kept stable in the pH range 4.0-10.0. Immunoaffinity chromatography (IAC) column was prepared by coupling antibody against enrofloxacin (ENR) with chitosan microparticles. Further characterization indicated that the binding capacity of the column was 4392ng ENR/mL gel and the variation of ENR extraction efficiency among columns was less than 5.2%. When challenged with ENR-fortified bovine milk samples, recoveries of ENR by immunoaffinity extraction were found to be in the range of 85.9% to 101.9%, demonstrated the feasibility of the prepared IAC columns for sample clean-up in ENR residue determination.