Mohammed Berrada

By Asmae Laaraibi, Fatiha Moughaoui, Fouad Damiri, Amine Ouakit, Imane Charhouf, Souad Hamdouch, Abdelhafid Jaafari, Abdelmjid Abourriche, Noureddine Knouzi, Ahmed Bennamara and Mohammed Berrada

The aim of this work is to design newer material for food packaging applications and to valorize the Moroccan marine wastes using chitosan (CS) prepared from exoskeletons of shrimps. Biodegradable and uniform nanocomposite films developed from sodium bentonite nanoparticles dispersed in chitosan matrix were carefully studied. The montmorillonite is used as nanofiller, and aqueous acetic acid solution is employed as a medium for dissolving and dispersing chitosan and montmorillonite. The existence of dialdehyde chitosan as cross-linking agent was examined. Morphology, thermal behavior, and mechanical properties of the nanocomposite films have been studied using FTIR, TGA, FEGSEM, TEM, XRD, and a tensile test. The XRD results indicate the formation of an intercalated and exfoliated nanostructure at low bentonite content and an intercalated and flocculated nanostructure at high bentonite content. Plastic deformation of the chitosan film is carried out using a thermomechanical treatment in the presence of a solvent and a plasticizer. The nanocomposite films obtained show a good tensile strength due to the reinforcement of chitosan intercalation in the silicate, which is an interesting mechanical property needed for food packaging applications. These nanocomposite films made from naturally occurring materials might play an important role in advanced research in food and environmental science.

Part of the book: Chitin-Chitosan

By Damiri Fouad, Yahya Bachra, Grouli Ayoub, Amine Ouaket, Ahmed Bennamara, Noureddine Knouzi and Mohammed Berrada

Recently, chitosan (CS) was given much attention as a functional biopolymer for designing various hydrogels for industrial, environmental and biomedical applications, but their biomedical use is limited due to the toxicity of the crosslinker agents. To overcome this inconvenience, we developed an auto cross-linked material based on a chitosan backbone that carries an amino and aldehyde moieties. This new drug delivery system (DDS) was designed by using oxidized chitosan (OCS) that crosslinks chitosan (CS). In the first part, a simple, rapid, low-cost and eco-friendly green method was introduced to synthesize magnetite nanoparticles (Fe3O4-NPs) successfully. These nanoparticles Fe3O4 have received a great deal of attention in the biomedical field. Especially in a targeted drug delivery system, drug-loaded Fe3O4-NPs can accumulate at the tumor site by the aid of an external magnetic field and increase the effectiveness of drug release to the tumor site. In the second part, we have incorporated the Fe3O4-NPs into chitosan/oxidized chitosan solution because of their unique magnetic properties, outstanding magnetism, biocompatibility, lower toxicity, biodegradability, and other features. Three drugs (5-Fluorouracil (5-FU), Caffeine and Ascorbic acid)) were embedded into the magnetite solution that became quickly a hydrogel. The successful fabrication of the hydrogels and ferrogels was confirmed by (FT-IR), (TGA), (SEM), (VSM) analysis at room temperature. Finally, results showed that our hydrogels and ferrogels may be technologically used as devices for drug delivery in a controllable manner.

Part of the book: Chitin and Chitosan

By Fouad Dabbarh, Noureddin Elbakali-Kassimi and Mohammed Berrada

Bone is the second most transplanted organ, just after blood. It provides structural support, protection for organs and soft tissues. It holds some critical biological processes such as the bone marrow blood forming system. It is responsible for storing and supplying minerals such calcium and phosphate. Bone is a connective tissue formed by two predominant phases: an inorganic phase containing mainly apatitic calcium and phosphate and an organic phase made of fibrous type I collagen. This natural biocomposite has many biological features such osteoconductivity, osteoinductivity, osteogenicity and is subject to a continuous remodeling process through osteoclastic and osteoblastic activities. In biomedical engineering, the restoration of damaged hard tissue with autologous bone is not always possible or even the best option. The development of some safe and low-cost alternatives such as biocomposites that mimic organic and calcified bone materials have shown very good results and offer an alternative to autologous bone implants. However, the mechanical properties of biocomposites still present a big challenge as a hard tissue substitute. This chapter reviews the properties of bone substitute materials chitosan and calcium phosphates, discusses strategies used in the treatment of calcified hard tissues as well as new approaches developed in this field.

Part of the book: Chitin and Chitosan