Green synthesis of antibacterial Ge-Sr phosphate scaffolds enhanced with eco-friendly pore-forming agents for biomedical use

This study investigates the development of composite ceramics for application in hard tissue augmentation, using GeO₂ and germanium-strontium phosphates as base materials. Various pore-forming agents, including cetyltrimethylammonium bromide (CTB), polyethylene (PE), caffeine (CFF), and natural materials such as lemon peel (LMN), silk (SLK), loofah (LFH), and yam (YAM), were employed to introduce porosity into the scaffolds. The impact of these agents on phase composition, particle size, and surface properties was analyzed, revealing that some agents induced phase transformations, while others preserved a multi-phase structure. The incorporation of phosphorus and strontium into the scaffolds to enhance bioactivity was evaluated using XRF analysis. The scaffolds' porosity, particularly meso- and macroporosity, was significantly influenced by the pore-forming agents. Antimicrobial activity, demonstrated against both gram-negative and gram-positive bacteria, was also an important factor for scaffolds intended for medical implants and wound healing. Among the materials tested, SGP-SLK and SGP-CTB showed the most promising results, combining excellent bioactivity, enhanced bone regeneration potential, and superior antimicrobial performance. These findings suggest that composite scaffolds incorporating phosphorus, strontium, and suitable porosity are promising candidates for tissue engineering applications.