The utilization of marine-based collagen is growing fast due to its unique properties in comparison with mammalian-based collagen such as no risk of transmitting diseases, a lack of religious constraints, a cost-effective process, low molecular weight, biocompatibility, and its easy absorption by the human body. This article presents an overview of the recent studies from 2014 to 2020 conducted on collagen extraction from marine-based materials, in particular fish by-products. The fish collagen structure, extraction methods, characterization, and biomedical applications are presented. More specifically, acetic acid and deep eutectic solvent (DES) extraction methods for marine collagen isolation are described and compared. In addition, the effect of the extraction parameters (temperature, acid concentration, extraction time, solid-to-liquid ratio) on the yield of collagen is investigated. Moreover, biomaterials engineering and therapeutic applications of marine collagen have been summarized.

Engineering biomaterials for tissue healing and regeneration using natural compounds have gained much attention in recent years. As a hydrolysable tannin derivative of gallic acid with several water-soluble polar groups...

In this work, phospho-calcified cellulose nanowhiskers (PCCNWs) were prepared from wastepaper powder (WPP) and were dispersed in poly­(ε-caprolactone) (PCL). The biocompatible and biodegradable (PCL)/PCCNW bimodal foam nanocomposites with two species cell sizes were prepared by the solvent casting/particulate leaching method in different weight percentage of PCCNWs. The mechanical, thermal, and in vitro biological properties of PCL/PCCNW nanocomposites were investigated. All PCL/PCCNW scaffolds were hydrophilic, biodegradable, and also noncytotoxic. The human mesenchymal stem cells were cultured on the prepared PCL/PCCNW bimodal foam nanocomposites and differentiated to osteoblasts. On the basis of evaluating tests such as MTT assay, acridine orange/ethidium bromide staining, alkaline phosphatase assay, calcium content assay, and alizarin red staining, PCL/PCCNW scaffolds were introduced as an appropriate option for emulating the behavior of extracellular matrix. Increasing PCCNWs improves the mechanical, hydrophilic, and biodegradability properties of the nanocomposites as well as their osteoconductivity.

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This study aims to valorize chitin polymer from the side stream of an insect farm and to determine the chitin content and its physicochemical properties obtained from different processing steps in the insect farm (Adult Black Soldier Fly insect, Puparia, and Flake). We used an acid-base method (using 1M HCl and 1M NaOH) as a conventional technique and the acid detergent fiber (ADF) with acid detergent lignin (ADL) methods. The chitin samples are then characterized for thermal stability (TGA-DTA), crystallinity (XRD), chemical compounds (FTIR), and C/N content, and the results were compared to the commercial shrimp chitin. The Puparia had the highest chitin content of 21-33%, followed by the Flake 20-28% and the Adult insect with 7-13% chitin, depending on the extraction method. The chitin yield from ADF-ADL method was on par with the conventional method, while the ADF results were approximately 3-10% higher than the ADF-ADL results. The insect farm side stream is an abundant rich source of high-quality chitin with physiochemical properties comparable with the commercially available shrimp derived chitin.

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Keratin dissolution is the first step toward reusing protein-rich biomass such as waste wool, hair, and feather.

An artificial ovary is a promising approach for preserving fertility in prepubertal girls and women who cannot undergo current cryopreservation strategies. However, this approach is in its infancy, due to the possible challenges of creating a suitable 3D matrix for encapsulating ovarian follicles and stromal cells. To maintain the ovarian stromal cell viability and proliferation, as a first step towards developing an artificial ovary, in this study, a double network hydrogel with a high water swelling capacity (swelling index 15–19) was developed, based on phenol conjugated chitosan (Cs-Ph) and silk fibroin (SF) through an enzymatic crosslinking method using horseradish peroxidase. The addition of SF (1%) to Cs (1%) decreased the storage modulus (G’) from 3500 Pa (Cs1) to 1600 Pa (Cs-SF1), and the hydrogels with a rapid gelation kinetic produced a spatially homogeneous distribution of ovarian cells that demonstrated 167% proliferation after 7 days. This new Cs-SF hydrogel benefits from the toughness and flexibility of SF, and phenolic chemistry could provide the potential microstructure for encapsulating human ovarian stromal cells.