Physiochemical and bactericidal activity evaluation: Silver‐augmented 3D‐printed scaffolds—An in vitro study

• Published in: Journal of biomedical materials research. Part B, Applied biomaterials Vol. 110; no. 1; pp. 195 - 209
• Main Authors: Nayak, Vasudev Vivekanand, Tovar, Nick, Hacquebord, Jacques Henri, Duarte, Simone, Panariello, Beatriz H. D., Tonon, Caroline, Atria, Pablo J., Coelho, Paulo G., Witek, Lukasz
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.01.2022; Wiley Subscription Services, Inc
• Subjects: 3D printing; Alkaline phosphatase; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; antibacterial; Antibacterial activity; Antiinfectives and antibacterials; Bactericidal activity; bioceramic; Biocompatibility; Biomedical materials; Bone and Bones; Bone grafts; Calcium phosphates; Calorimetry; Cytotoxicity; Differential scanning calorimetry; Electron microscopy; Fluorescence; Fourier analysis; Fourier transforms; human osteoblast precursor; Humans; Inductively coupled plasma mass spectrometry; Infrared spectroscopy; Ions; Mass spectroscopy; Materials research; Materials science; metathesis reaction; Methicillin; Microscopy; Morbidity; Osteoblasts; Osteoprogenitor cells; Physical properties; Physiochemistry; Printing, Three-Dimensional; Scaffolds; Silver; Silver nitrate; Spectrum analysis; Staphylococcus aureus; Substitute bone; Thermogravimetric analysis; Three dimensional printing; Tissue Scaffolds - chemistry; Toxicity; Tricalcium phosphate; X-ray diffraction; metathesis reaction; bioceramic; antibacterial; human osteoblast precursor; 3D printing; Staphylococcus aureus
• DOI: 10.1002/jbm.b.34902
• ISSN: 1552-4973; 1552-4981

Hypothesis Injuries requiring resection of tissue followed by autogenous bone transfer may be prone to infection by Staphylococcus aureus, impeding recovery and increasing medical costs. For critical sized defects, the common approach to reconstruction is a tissue transfer procedure but is subject to limitations (e.g., donor site morbidity, cost, operating time). Utilizing beta tricalcium phosphate (β‐TCP) as bone grafting material augmented with silver (Ag), a custom graft may be 3D printed to overcome limitations and minimize potential infections. Experiments Scaffolds were 3D printed and augmented with Ag by external attack on the surface by silver nitrate (AgNO3) at varying concentrations (0.1, 1.0, 10% wt/wt of scaffold). The augmented scaffolds were evaluated utilizing X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and inductively coupled plasma mass spectroscopy (ICP‐MS) to verify the presence of Ag and phosphate (PO4) groups followed by electron microscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) to gather information of chemical and physical properties. Preliminary biocompatibility and bactericidal capacity of the scaffolds were tested using human osteoprogenitor (hOP) cells and methicillin‐sensitive S. aureus strain, respectively. Results XRD, FTIR, ICP‐MS, TGA, and DSC confirmed presence of Ag and PO4 groups, whereas electron microscopy showed a decrease in Ca and an increase in Ag ions, decreasing Ca/P ratio with increasing surfactant concentrations. PrestoBlue assays yielded an increase in fluorescence cell counts among experimental groups with lower concentrations of Ag characterized by their characteristic trapezoidal shape whereas cytotoxicity was observed at higher concentrations. Similar observations were made with alkaline phosphatase assays. Antimicrobial evaluation showed reduced colony‐forming units (CFU) among all experimental groups when compared to 100% β‐TCP. β‐TCP scaffolds augmented with Ag ions facilitate antibacterial effects while promoting osteoblast adhesion and proliferation.