During the processing of the fishery resources, the significant portion is either discarded or used to produce low-value fish meal and oil. However, the discarded portion is the rich source of valuable proteins such as collagen, vitamins, minerals, and other bioactive compounds. Collagen is a vital protein in the living body as a component of a fibrous structural protein in the extracellular matrix, connective tissue and building block of bones, tendons, skin, hair, nails, cartilage and joints. In recent years, the use of fish collagen as an increasingly valuable biomaterial has drawn considerable attention from biomedical researchers, owing to its enhanced physicochemical properties, stability and mechanical strength, biocompatibility and biodegradability. This review focuses on summarizing the growing role of fish collagen for biomedical applications. Similarly, the recent advances in various biomedical applications of fish collagen, including wound healing, tissue engineering and regeneration, drug delivery, cell culture and other therapeutic applications, are discussed in detail. These applications signify the commercial importance of fish collagen for the fishing industry, food processors and biomedical sector.

Background: Increasing antibiotic resistance continues to focus on research into the discovery of novel antimicrobial agents. Due to its antimicrobial and wound healing-promoting activity, metal nanoparticles have attracted attention for dermatological applications. This study is designed to investigate the scope and bactericidal potential of zinc ferrite nanoparticles (ZnFe₂O₄NPs), and the mechanism of anti-bacterial action along with cytocompatibility, hemocompatibility, and wound healing properties.Results: ZnFe₂O₄NPs were synthesized via a modified co-precipitation method. Structure, size, morphology, and elemental compositions of ZnFe₂O₄NPs were analyzed using X-ray diffraction pattern, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. In PrestoBlue and live/dead assays, ZnFe₂O₄NPs exhibited dose-dependent cytotoxic effects on human dermal fibroblasts. In addition, the hemocompatibility assay revealed that the NPs do not significantly rupture red blood cells up to a dose of 1000 µg/mL. Bacterial live/dead imaging and zone of inhibition analysis demonstrated that ZnFe₂O₄NPs showed dose-dependent bactericidal activities in various strains of Gram-negative and Gram-positive bacteria. Interestingly, NPs showed antimicrobial activity through multiple mechanisms, such as cell membrane damage, protein leakage, and reactive oxygen species generation, and were more effective against gram-positive bacteria. Furthermore, in vitro scratch assay revealed that ZnFe₂O₄NPs improved cell migration and proliferation of cells, with noticeable shrinkage of the artificial wound model.Conclusions: This study indicated that ZnFe₂O₄NPs have the potential to be used as a future antimicrobial and wound healing drug.

The development of novel cutaneous wound treatments particularly for burns is of paramount importance due to complex pathophysiology, prevalent infection and clinical complexities associated with burn care. The main focus of the current study was to investigate the in vivo burn wound healing potential of bacterial cellulose (BC) and titanium dioxide (TiO₂) nanocomposites (BC–TiO₂). The physicochemical characterization of BC–TiO₂ was carried out using FE-SEM, XRD and FT-IR. The antimicrobial activity of the nanocomposite was tested against Escherichia coli and Staphylococcus aureus through agar disc diffusion protocol. The in vivo wound healing efficacy was evaluated in burn wound model through wound area measurement, percent contraction and histopathology. The characterization results confirmed the successful incorporation of TiO₂ nanoparticles into BC. The nanocomposites exhibited 81 ± 0.4% and 83 ± 0% inhibition against E. coli and S. aureus, respectively. The composite bandage showed good healing pattern with 71 ± 2.41% wound contraction. Histopathological evidence like the formation of healthy granulation tissue and the re-epithelization indicated the healing progression in the composite treated group. In comparison, the BC treated group has partial epithelization and signs of inflammation. These results proved that the composite dressing possesses an excellent healing potential with faster re-epithelization rate and accelerated wound contraction ability and thus could be a candidate for the development of cutaneous wound care products to address the limitations of the conventional wound dressing for burns.

Low availability of phosphorus (P) in calcareous soils is a major problem for sustainable improvement in cereals crops yield. A higher amount of calcium in soils precipitates the P, thus making it immobile in soil. Inoculation of arbuscular mycorrhizal fungi (AMF) and phosphate solubilizing bacteria (PSB) could be helpful in the sustainable management of immobile P in soil. However, their combined use in releasing P from rock phosphate (RP) in alkaline calcareous soils have been little investigated. In this regard, two successive field experiments were conducted to assess the interactive inoculation potential of AMF and PSB strain Bacillus sp. PIS7 with RP on the yield and P uptake of maize (Zea mays L.) and wheat (Triticum aestivum L.) crops in alkaline calcareous soil. The first field experiment was conducted in a complete randomized block design with 10 treatments and three replications by inoculating maize seeds with AMF and Bacillus sp. PIS7 inoculum alone and in combination with RP. Their performance was compared with single super phosphate (SSP) inorganic fertilizer. Afterward, the residual effects of inoculated AMF and Bacillus sp. PIS7 were investigated on wheat as a subsequent crop. Maize and wheat yield parameters, P uptake, AMF root colonization, and PSB population was measured. The results of both trials indicated the beneficial effects of AMF and Bacillus sp. PIS7 with RP in increasing the plants grain yield and P uptake until the second season after inoculation, as compared to controls. Likewise, maize and wheat roots colonization, PSB population density, and post-harvest soil properties were also improved by the combined inoculation of AMF and Bacillus sp. PIS7 with RP. It is concluded that PSB solubilizes the unavailable forms of P in combination with RP fertilizers in soil, and AMF ultimately transfers it to plants for growth promotion. Moreover, the combined inoculation of AMF and PSB with ground RP had more potential to improve maize-wheat yields and P uptake comparable to those obtained by using expensive phosphatic fertilizers in P deficient calcareous pH soils.