Colloids and Surfaces B: Biointerfaces 167 (2018) 310–317 Contents lists available at ScienceDirect Colloids and Surfaces B: Biointerfaces jo ur nal ho me p ag e: www.elsevier.com/locate/colsurfb Fish sarcoplasmic proteins as a high value marine material for wound dressing applications Sara Vieira a,b , Albina R. Franco a,b , Emanuel M. Fernandes a,b , Sara Amorim a,b , Helena Ferreira a,b , Ricardo A. Pires a,b , Rui L. Reis a,b,c , Albino Martins a,b , Nuno M. Neves a,b,c,∗ a 3B’s Research Group – Biomaterials, Biodegradables and Biomimetics, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Minho, Avepark 4805-017 Barco, Guimarães, Portugal b ICVS/3B’s – PT Government Associate Laboratory, Braga, Guimarães, Portugal c The Discoveries Centre for Regenerative and Precision Medicine, Headquarters at University of Minho, Avepark 4805-017 Barco, Guimarães, Portugal a r t i c l e i n f o Article history: Received 30 November 2017 Received in revised form 1 March 2018 Accepted 1 April 2018 Available online 5 April 2018 Keywords: Cytocompatibility Membranes Physico-chemical characterization Sarcoplasmic proteins Spin coating a b s t r a c t Fish sarcoplasmic proteins (FSP) constitute around 25–30% of the total fish muscle protein. As the FSP are water soluble, FSP were isolated from fresh cod (Gadus morhua) by centrifugation. By SDS-PAGE, it was possible to determine the composition of FSP extracts (FSP-E). The FSP-E undergo denaturation at 44.12 ± 2.34 ◦ C, as characterized by differential scanning calorimetry thermograms (DSC). The secondary structure of FSP-E is mainly composed by -helix structure, as determined by circular dichroism. The cyto- compatibility of FSP-E, at concentrations ranging from 5 to 20 mg/mL, was investigated. Concentrations lower than 10 mg/mL have no cytotoxicity cultures of fibroblasts over 72 h. Further on, FSP membranes (FSP-M) were produced by spin coating to evaluate its properties. FSP-M shown having uniform sur- face as analyzed by Scanning Electron Microscopy (SEM). The relative amount of -helix structures is higher when compared with the FSP-E. The FSP-M have higher temperature stability than the FSP-E, since they presented a denaturation temperature of 58.88 ± 3.36 ◦ C, according to the DSC analysis. FSP- M shown distinctive mechanical properties, with a stiffness of 16.57 ± 3.95 MPa and a yield strength of 23.85 ± 5.97 MPa. Human lung fibroblasts cell lines (MRC-5) were cultured in direct contact with FSP-M, demonstrating its cytocompatibility for 48 h. Based on these results, FSP can be considered a potential biomaterial recovered from nature, for wound dressing applications. © 2018 Elsevier B.V. All rights reserved. 1. Introduction The proteins of the fish muscle can be divided into three major classes, based on their solubility in aqueous solutions: con- nective tissue (stroma) proteins (3%), myofibrillar proteins (MP) (70–80%) or sarcoplasmic proteins (SPs) (25–30%) [1]. The MP and the stroma proteins are water insoluble, whereas the SPs are sol- uble in water. Fish sarcoplasmic proteins (FSP) comprise several types of proteins, including heme proteins [2] (hemoglobin and myoglobin) and enzymes, such as creatine kinase [3], aldolase [3], glyceraldehyde-3-phosphate dehydrogenase (GAPDH) [3], phos- ∗ Corresponding author at: 3B’s Research Group – Biomaterials, Biodegradables and Biomimetics, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Minho, Avepark 4805-017 Barco, Guimarães, Portugal. E-mail address: nuno@dep.uminho.pt (N.M. Neves). phorylase [4], proteinase inhibitors [5], proteases A and C [6], phospholipase [7], peroxidase [8], transglutaminase (TGase) [9], fructose-bisphosphate aldolase A [10], glycogen phosphorylase [10], beta-enolase [10], triosephosphate isomerase B [10], phos- phoglucomutase [10], phosphoglycerate kinase [10], parvalbumins and calmodulins [1,11]. Over the last years, fish proteins have been proposed as edible biopolymer films to protect and preserve food or as pharmaceu- ticals, mainly due to their advantages over synthetic polymers such as their biodegradability [12–14]. Only a few studies with FSP demonstrated the film-forming potential of those materials [15,16]. Sett et al. proposed a mixture of FSP from codfish (Gadus morhua) with nylon 6 as a substitute of traditional synthetic polymers [17]. In the biomedical field, Stephansen et al. developed and charac- terized a bioactive electrospun nano/micro-fiber mesh based on FSP from codfish [18], proposing the system for the gastrointestinal delivery of insulin [19]. Stephansen et al. also proposed nanocom- plexes obtained by the electrostatic self-assembling complexation, https://doi.org/10.1016/j.colsurfb.2018.04.002 0927-7765/© 2018 Elsevier B.V. All rights reserved.