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The efficient healing of critical-sized bone defects using synthetic biomaterial-based strategies is promising but remains challenging as it requires the development of biomaterials that combine a 3D porous architecture and a robust biological activity. Bioactive glasses (BGs) are attractive candidates as they stimulate a biological response that favors osteogenesis and vascularization, but amorphous 3D porous BGs are difficult to produce because conventional compositions crystallize during processing. Here, we rationally designed a porous, strontium-releasing, bioactive glass-based scaffold (pSrBG) whose composition was tailored to deliver strontium and whose properties were optimized to retain an amorphous phase, induce tissue infiltration and encourage bone formation. The hypothesis was that it would allow the repair of a critical-sized defect in an ovine model with newly-formed bone exhibiting physiological matrix composition and structural architecture. Histological and histomorphometric analyses combined with indentation testing showed pSrBG encouraged near perfect bone-to-material contact and the formation of well-organized lamellar bone. Analysis of bone quality by a combination of Raman spectral imaging, small-angle X-ray scattering, X-ray fluorescence and focused ion beam-scanning electron microscopy demonstrated that the repaired tissue was akin to that of normal, healthy bone, and incorporated small amounts of strontium in the newly formed bone mineral. These data show the potential of pSrBG to induce an efficient repair of critical-sized bone defects and establish the importance of thorough multi-scale characterization in assessing biomaterial outcomes in large animal models.

New aromatic molecule–seed particle interactions are examined and exploited to control and guide seed-mediated gold nanorod (Au NR) growth. This new approach enables better understanding of how small molecules impact the synthesis of metallic nanostructures, catalysing their use in various biomedical applications, such as plasmonic biosensing. We perform experimental studies and theoretical molecular simulations using a library of aromatic molecules where we take advantage of the chemical versatility of the molecules with varied spatial arrangements of electron donating/withdrawing groups, charge, and Au-binding propensity. Au NR growth is regulated by two principal mechanisms, producing either a red or blue shift in the longitudinal localized surface plasmon resonance (LLSPR) peaks. Aromatic molecules with high redox potentials produced an increase in NR aspect ratio and red shift of LLSPR peaks. In contrast, molecules that strongly bind gold surfaces resulted in blue shifts, demonstrating a strong correlation between their binding energy and blue shifts produced. Through enzymatic conversion of selected molecules, 4-aminophenylphosphate to 4-aminophenol, we obtained opposing growth mechanisms at opposite extremes of target concentration, and established a chemical pathway for performing plasmonic ELISA. This unlocks new strategies for tailoring substrate design and enzymatic mechanisms for controlling plasmonic response to target detection in biosensing applications.