Chitin and Chitosan: Prospective Biomedical Applications in Drug Delivery,Cancer Treatment,and Wound Healing

Chitin and its derivative chitosan are highly abundant polymers in nature, appearing in both the shells and exoskeletons of various marine and non-marine species. Since they possess favorable properties, such as biocompatibility, biodegradability, non-toxicity, and non-immunogenicity, they have gained recent attention due to their enormous potential biomedical applications. The polycationic surface of chitosan enables it to form hydrogenic and ionic bonds with drug molecules, which is one of its most useful properties. Because chitosan is biocompatible, it can therefore be used in drug delivery systems. The development of chitosan-based nanoparticles has also contributed to the significance of chitin as a drug delivery system that can deliver drugs topically. Furthermore, chitin can be used in cancer treatment as a vehicle for delivering cancer drugs to a specific site and has an antiproliferative effect by reducing the viability of cells. Finally, chitosan can be used as a wound dressing in order to promote the faster regeneration of skin epithelial cells and collagen production by fibroblasts. As discussed in this review, chitin and chitosan have diverse applications in the medical field. Recognizing the biomedical applications of these two polymers is essential for future research in tissue engineering and nanobiotechnology.     

Preparation of Alginate-Based Biomaterials and Their Applications in Biomedicine

Alginates are naturally occurring polysaccharides extracted from brown marine algae and bacteria. Being biocompatible, biodegradable, non-toxic and easy to gel, alginates can be processed into various forms, such as hydrogels, microspheres, fibers and sponges, and have been widely applied in biomedical field. The present review provides an overview of the properties and processing methods of alginates, as well as their applications in wound healing, tissue repair and drug delivery in recent years.     

Marine Polysaccharides as a Versatile Biomass for the Construction of Nano Drug Delivery Systems

Marine biomass is a treasure trove of materials. Marine polysaccharides have the characteristics of biocompatibility, biodegradability, non-toxicity, low cost, and abundance. An enormous variety of polysaccharides can be extracted from marine organisms such as algae, crustaceans, and microorganisms. The most studied marine polysaccharides include chitin, chitosan, alginates, hyaluronic acid, fucoidan, carrageenan, agarose, and Ulva. Marine polysaccharides have a wide range of applications in the field of biomedical materials, such as drug delivery, tissue engineering, wound dressings, and sensors. The drug delivery system (DDS) can comprehensively control the distribution of drugs in the organism in space, time, and dosage, thereby increasing the utilization efficiency of drugs, reducing costs, and reducing toxic side effects. The nano-drug delivery system (NDDS), due to its small size, can function at the subcellular level in vivo. The marine polysaccharide-based DDS combines the advantages of polysaccharide materials and nanotechnology, and is suitable as a carrier for different pharmaceutical preparations. This review summarizes the advantages and drawbacks of using marine polysaccharides to construct the NDDS and describes the preparation methods and modification strategies of marine polysaccharide-based nanocarriers.     

Biocompatibility of the Biopolymer Cyanoflan for Applications in Skin Wound Healing

There is a great demand for the development of novel wound dressings to overcome the time and costs of wound care performed by a vast number of clinicians, especially in the current overburdened healthcare systems. In this study, Cyanoflan, a biopolymer secreted by a marine unicellular cyanobacterium, was evaluated as a potential biomaterial for wound healing. Cyanoflan effects on cell viability, apoptosis, and migration were assessed in vitro, while the effect on tissue regeneration and biosafety was evaluated in healthy Wistar rats. The cell viability and apoptosis of fibroblasts and endothelial cells was not influenced by the treatment with different concentrations of Cyanoflan, as observed by flow cytometry. Moreover, the presence of Cyanoflan did not affect cell motility and migratory capacity, nor did it induce reactive oxygen species production, even revealing an antioxidant behavior regarding the endothelial cells. Furthermore, the skin wound healing in vivo assay demonstrated that Cyanoflan perfectly adapted to the wound bed without inducing systemic or local oxidative or inflammatory reaction. Altogether, these results suggest that Cyanoflan is a promising biopolymer for the development of innovative applications to overcome the many challenges that still exist in skin wound healing.     

Marine Collagen: A Promising Biomaterial for Wound Healing,Skin Anti-Aging,and Bone Regeneration

Marine organisms harbor numerous bioactive substances that can be utilized in the pharmaceutical and cosmetic industries. Scientific research on various applications of collagen extracted from these organisms has become increasingly prevalent. Marine collagen can be used as a biomaterial because it is water soluble, metabolically compatible, and highly accessible. Upon review of the literature, it is evident that marine collagen is a versatile compound capable of healing skin injuries of varying severity, as well as delaying the natural human aging process. From in vitro to in vivo experiments, collagen has demonstrated its ability to invoke keratinocyte and fibroblast migration as well as vascularization of the skin. Additionally, marine collagen and derivatives have proven beneficial and useful for both osteoporosis and osteoarthritis prevention and treatment. Other bone-related diseases may also be targeted by collagen, as it is capable of increasing bone mineral density, mineral deposition, and importantly, osteoblast maturation and proliferation. In this review, we demonstrate the advantages of marine collagen over land animal sources and the biomedical applications of marine collagen related to bone and skin damage. Finally, some limitations of marine collagen are briefly discussed.     

Potential Biomedical Applications of Collagen Filaments derived from the Marine Demosponges Ircinia oros (Schmidt, 1864) and Sarcotragus foetidus (Schmidt, 1862)

Collagen filaments derived from the two marine demosponges Ircinia oros and Sarcotragus foetidus were for the first time isolated, biochemically characterised and tested for their potential use in regenerative medicine. SDS-PAGE of isolated filaments revealed a main collagen subunit band of 130 kDa in both of the samples under study. DSC analysis on 2D membranes produced with collagenous sponge filaments showed higher thermal stability than commercial mammalian-derived collagen membranes. Dynamic mechanical and thermal analysis attested that the membranes obtained from filaments of S. foetidus were more resistant and stable at the rising temperature, compared to the ones derived from filaments of I. oros. Moreover, the former has higher stability in saline and in collagenase solutions and evident antioxidant activity. Conversely, their water binding capacity results were lower than that of membranes obtained from I. oros. Adhesion and proliferation tests using L929 fibroblasts and HaCaT keratinocytes resulted in a remarkable biocompatibility of both developed membrane models, and gene expression analysis showed an evident up-regulation of ECM-related genes. Finally, membranes from I. oros significantly increased type I collagen gene expression and its release in the culture medium. The findings here reported strongly suggest the biotechnological potential of these collagenous structures of poriferan origin as scaffolds for wound healing.     

Electrolysis as a Universal Approach for Isolation of Diverse Chitin Scaffolds from Selected Marine Demosponges

Three-dimensional chitinous scaffolds often used in regenerative medicine, tissue engineering, biomimetics and technology are mostly isolated from marine organisms, such as marine sponges (Porifera). In this work, we report the results of the electrochemical isolation of the ready to use chitinous matrices from three species of verongiid demosponges (Aplysina archeri, Ianthella basta and Suberea clavata) as a perfect example of possible morphological and chemical dimorphism in the case of the marine chitin sources. The electrolysis of concentrated Na₂SO₄ aqueous solution showed its superiority over the chemical chitin isolation method in terms of the treatment time reduction: only 5.5 h for A. archeri, 16.5 h for I. basta and 20 h for the S. clavata sample. Further investigation of the isolated scaffolds by digital microscopy and SEM showed that the electrolysis-supported isolation process obtains chitinous scaffolds with well-preserved spatial structure and it can be competitive to other alternative chitin isolation techniques that use external accelerating factors such as microwave irradiation or atmospheric plasma. Moreover, the infrared spectroscopy (ATR-FTIR) proved that with the applied electrochemical conditions, the transformation into chitosan does not take place.