**Surface Characterization and Physiochemical Evaluation of P(3HB-***co***-4HB)-Collagen Peptide Scaffolds with Silver Sulfadiazine as Antimicrobial Agent for Potential Infection-Resistance Biomaterial**

**Sevakumaran Vigneswari <sup>1</sup> , Tana Poorani Gurusamy 2, Wan M. Khairul 1, Abdul Khalil H.P.S. <sup>3</sup> , Seeram Ramakrishna <sup>4</sup> and Al-Ashraf Abdullah Amirul 2,5,6,\***


**Abstract:** Poly(3-hydroxybutyrate-*co*-4-hydroxybutyrate) [P(3HB-*co*-4HB)] is a bacterial derived biopolymer widely known for its unique physical and mechanical properties to be used in biomedical application. In this study, antimicrobial agent silver sulfadiazine (SSD) coat/collagen peptide coat-P(3HB-*co*-4HB) (SCCC) and SSD blend/collagen peptide coat-P(3HB-*co*-4HB) scaffolds (SBCC) were fabricated using a green salt leaching technique combined with freeze-drying. This was then followed by the incorporation of collagen peptides at various concentrations (2.5–12.5 wt.%) to P(3HB-*co*-4HB) using collagen-coating. As a result, two types of P(3HB-*co*-4HB) scaffolds were fabricated, including SCCC and SBCC scaffolds. The increasing concentrations of collagen peptides from 2.5 wt.% to 12.5 wt.% exhibited a decline in their porosity. The wettability and hydrophilicity increased as the concentration of collagen peptides in the scaffolds increased. In terms of the cytotoxic results, MTS assay demonstrated the L929 fibroblast scaffolds adhered well to the fabricated scaffolds. The 10 wt.% collagen peptides coated SCCC and SBCC scaffolds displayed highest cell proliferation rate. The antimicrobial analysis of the fabricated scaffolds exhibited 100% inhibition towards various pathogenic microorganisms. However, the SCCC scaffold exhibited 100% inhibition between 12 and 24 h, but the SBCC scaffolds with SSD impregnated in the scaffold had controlled release of the antimicrobial agent. Thus, this study will elucidate the surface interface-cell interactions of the SSD-P(3HB-*co*-4HB)-collagen peptide scaffolds and controlled release of SSD, antimicrobial agent.

**Keywords:** P(3HB-*co*-4HB); silver sulfadiazine; collagen peptide; infection-resistance scaffolds
