Implant-associated-infections against the background of multi-drug-resistance cause severe complications in orthopedic and trauma surgery and burden global healthcare. Equipment of implants with antibacterial coatings loaded by lytic bacteriophages (PHAG) are seen promising in this respect. Here, we report antibacterial polyelectrolyte multilayer (PEM) coatings functionalized by PHAG, which were deposited at model substrates and metallic implants by consecutive adsorption from solutions of poly-l-lactide-modified hyaluronic acid (DAC), ethylenediamino-cellulose (EDAC) or poly(ethyleneimine) (PEI) according to layer-by-layer technique. PHAG against Staphylococcus aureus (S. aureus) bacteria were bound at five- and six-layered PEM coatings of PEI/DAC or EDAC/DAC, respectively. PEM deposition and PHAG interaction were studied by FTIR and SFM. In-vivo antibacterial properties of PHAG/PEM coatings against S. aureus bacteria were evaluated using Galleria mellonella (G. mellonella) larvae infection model. PEM coatings of EDAC/DAC revealed far higher deposited polymer amounts compared to PEI/DAC and far more PHAG were bound at thicker EDAC/DAC compared to thinner PEI/DAC coatings. Higher relative released PHAG amount (40-80%) was found for thinner PEI/DAC coatings, while lower one (10-20%) for thicker EDAC/DAC coatings. In-vivo studies revealed survival rates >80% of uninfected G. mellonella larvae treated with uncoated and PEM/PHAG coated metallic implants, indicating biocompatibility of the used materials. Infected G. mellonella larvae showed survival rates of 33%-43% for metallic implants with PEM/PHAG coatings of EDAC/DAC, which were higher with statistical significance compared to uncoated controls (13%), indicating excellent antibacterial properties.

The rising demand for safe and effective alternatives for bone regeneration has spurred extensive research into biomaterials derived from marine collagen. This systematic review aimed to evaluate the feasibility of marine collagen-based compounds and derived constructs for bone regeneration in in vivo preclinical models while critically assessing the methodological quality of the included studies. The review was conducted following PRISMA guidelines, utilizing the PICO framework to delineate the scope and research focus. After applying predefined inclusion and exclusion criteria, a comprehensive search across multiple databases identified 15 eligible studies. Methodological quality was appraised using the ARRIVE 2.0 guidelines, and the risk of bias was weighed through the SYRCLE tool. The selected studies evaluated collagens derived from fish and marine sponges, which were processed into scaffolds, membranes, and hydrogels. These biomaterials exhibited notable biocompatibility, osteoconductivity, and efficacy in promoting new bone formation. Furthermore, synergistic combinations with hydroxyapatite, chitosan, and growth factors such as BMP-2 significantly enhanced their regenerative capacity. However, several critical shortcomings were observed in experimental designs, including inadequate randomization, absence of blinding, and insufficient reporting of animal handling protocols. These limitations raise concerns regarding reproducibility and the overall validity of the findings. In conclusion, marine collagen-based biomaterials hold significant potential for bone regeneration applications. Nevertheless, achieving greater standardization and methodological rigor in preclinical research is paramount to ensuring their successful clinical translation.